CN105593610A

CN105593610A - Heat pump system, and heat pump water heater

Info

Publication number: CN105593610A
Application number: CN201480053999.4A
Authority: CN
Inventors: 大村峰正; 冈田拓也; 馆石太一; 佐藤创
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Air Conditioning and Refrigeration Systems Corp
Priority date: 2013-09-30
Filing date: 2014-07-31
Publication date: 2016-05-18
Anticipated expiration: 2034-07-31
Also published as: WO2015045247A1; CN107270570A; EP3040643B1; EP3040643A1; EP3040643A4; ES2708779T3; CN105593610B

Abstract

Provided is a two-stage compression heat pump with which the amount of refrigerant oil in the two compressors is easily kept uniform. The system is provided with: a compression mechanism (10) provided with a lower stage-side compressor (10a) and a higher stage-side compressor (10b), for compressing and discharging a refrigerant; a water-refrigerant heat exchanger (11) for heat exchange between a target to undergo heat exchange and the refrigerant compressed by the compression mechanism (10); an expansion valve (12) for decompression and expansion of the refrigerant outflowing from the water-refrigerant heat exchanger (11); a heat source-side heat exchanger (13) for heat exchange between a target to undergo heat exchange and the refrigerant decompressed and expanded by the expansion valve (12); an oil equalizing mechanism (20) connecting the lower stage-side compressor (10a) and the higher stage-side compressor (10b), through which a refrigerant oil flows; and a four-way switching valve (14) for selectively switching between a two-stage compression path in which the refrigerant flows in order to the lower stage-side compressor (10a) and the higher stage-side compressor (10b), and a one-stage compression path in which it flows either to the lower stage-side compressor (10a) or the higher stage-side compressor (10b) only.

Description

Heat pump and heat-pump-type hot-warer supplying machine

Technical field

The present invention relates to a kind of two independently heat pumps of the two-stage compression formula of compressor that are connected in series with.

Background technology

Carrying out the heat pump of hot-water supply system taking energy-conservation as object.

As its refrigerant system, known have a following two-stage compression kind of refrigeration cycle, and it possesses and is connected in series with rudimentary side pressureThe refrigerant loop of contracting machine and senior side compressor, utilize this refrigerant loop make refrigerant circulation (for example, patent documentation 1～3)。

Conventional art document

Patent documentation

Patent documentation 1: Japanese kokai publication hei 5-93552 communique

Patent documentation 2: Japanese kokai publication hei 6-2966 communique

Patent documentation 3: TOHKEMY 2009-168330 communique

The summary of invention

The technical task that invention will solve

For two-stage compression kind of refrigeration cycle is moved all the time under the good state of efficiency, need to make rudimentary side and heightTwo compressors of level side move with rotating speed independently respectively. Therefore, become maximum problem be control two compressionsIn machine, distinguish the oil level level of contained refrigerating machine oil. Be equipped with rudimentary side and senior side two in the inside of 1 housingThe compressor difference of compressing mechanism, when series connection links two independently when compressor, for two compressors are firmly moved,Need to the amount of refrigerating machine oil be remained to suitable, impartial level between two compressors.

The present invention completes based on this technical task, and it is a kind of without out of service or answer that its object is to provideAssorted operation and easily keep equably the secondary compression heat pump system of the amount of the refrigerating machine oil of two compressors. In addition,The object of the present invention is to provide a kind of high efficiency heat-pump hot water supply apparatus that possesses this two-stage compression formula heat pump.

For the means of technical solution problem

The present invention who completes based on this object is divided into the first invention and the second invention.

First, the related heat pump of the first invention, it possesses: compressing mechanism, possesses rudimentary side compressor and seniorSide compressor, compresses and the cold-producing medium that spues; Oil eliminator, is arranged at the exhaust end of senior side compressor; The 1st heat exchanger, makesThe cold-producing medium being compressed by compressing mechanism and heat exchange object carry out heat exchange; Expansion valve, makes the refrigeration flowing out from the 1st heat exchangerAgent puffing; The 2nd heat exchanger, makes the cold-producing medium of puffing in expansion valve and heat exchange object carry out heat exchange; AllOil circuit footpath, links rudimentary side compressor and senior side compressor, makes refrigerating machine oil at rudimentary side compressor and senior side compressorBetween circulation; The main pipe arrangement that returns, links between oil eliminator and the suction side of senior side compressor; Oil return path, links main returningGo back to pipe arrangement and equal oil circuit footpath; Oil return open and close valve, is arranged at oil return path; And refrigerant path switching mechanism, make cold-producing mediumFlow through successively the two-stage compression path of rudimentary side compressor and senior side compressor and only flow through rudimentary side compressor and senior sideBetween the one-level compressed path of any one in compressor, selectively switch.

For example, if imagination is set the hot-warer supplying machine of heat-pump-type, because depending on, the high-pressure of equipment enters water refrigerationThe temperature (for example, the scope of 35～75 DEG C) of the water in agent heat exchanger (water-refrigerant heat exchanger) is determined, therefore pressesThe suction side of contracting machine and the pressure differential of exhaust end may significantly change because of water temperature. If in entering of water-refrigerant heat exchangerUnder the lower state of saliva temperature, carry out two-stage compression operation, the differential pressure between rudimentary side compressor and senior side compressor becomesLittle. According to the differential pressure of this compressor chamber, determine the amount of the refrigerating machine oil returning. Therefore,, in the present invention, carrying out two-stage compressionWhen operation, if the differential pressure between rudimentary side compressor and senior side compressor reduces, be switched to one-level compression operation.

In the heat pump of the first invention, if in the time having selected the state in two-stage compression path, below meetingAny one in condition (1)～condition (3), the path of cold-producing medium is switched to one-level compressed path.

Condition (1): T_W≤T_R

T_W: in the time that the heat exchange object of the 1st heat exchanger is water, enter in water refrigerant heat exchanger (hydrothermal exchange)The temperature of water, T_R: setting

Condition (2): (P_HO-P_LI)≤ΔP_R1

P_LI: the suction pressure of rudimentary side compressor, P_HO: the pressure that spues of senior side compressor, setting: Δ P_R1

Condition (3): (P_LO-P_LI)≤ΔP_R2

P_LI: the suction pressure of rudimentary side compressor, P_LO: the pressure that spues of rudimentary side compressor, setting: Δ P_R2

And in the heat pump of the first invention, if select one-level compressed path, refrigerant path switching mechanism canBy opening oil return open and close valve, make from the refrigerating machine oil of oil eliminator not via senior side compressor via oil return pathTurn back to equal oil circuit footpath.

By the oil return path of above structure, equal oil circuit footpaths are set, at rudimentary side compressor, senior side compressor separatelyWhen the quantity not sufficient of refrigerating machine oil, can easily recover oil mass.

In the heat pump of the first invention, preferably according to the amount of the refrigerating machine oil of the prediction in rudimentary side compressor and seniorThe amount of the refrigerating machine oil of the prediction in side compressor is controlled and is returned with the switching of open and close valve and all switchings of oil open and close valve.

Two compressors obtaining according to the sensing result of the pressure sensor being possessed by heat pump, temperature sensorOil mass separately, can control refrigerating machine oil in the suitable moment.

The 1st heat exchanger of heat pump described above is carried out water as making cold-producing medium and water carry out heat exchangeThe heat-pump-type hot-warer supplying machine of the water-refrigerant heat exchanger of heating is due to the refrigeration machine of rudimentary side compressor and senior side compressorMeasuring of oil guaranteed, therefore can stably realize high efficiency hot water supply.

Secondly, the heat pump of the second invention possesses: compressing mechanism, possess rudimentary side compressor and senior side compressor,Compress and the cold-producing medium that spues; The 1st heat exchanger, the cold-producing medium being compressed by compressing mechanism and heat exchange object carry out heat exchange; SwollenSwollen valve, makes the cold-producing medium puffing flowing out from the 1st heat exchanger; The 2nd heat exchanger, the system of puffing in expansion valveCryogen and heat exchange object carry out heat exchange; Equal oily pipe arrangement, links rudimentary side compressor and senior side compressor, makes refrigerating machine oilBetween rudimentary side compressor and senior side compressor, circulate; All fuel tap, opens and closes equal oily pipe arrangement; And control device, control all oilThe on-off action of valve.

Flow through equal oily pipe arrangement if control device of the present invention is judged as cold-producing medium, the equal fuel tap of opening is closed in instruction.

In the heat pump of the second invention, control device can be according to the detected temperatures T in equal oily pipe arrangement₀With make cold-producing mediumDetected temperatures T from rudimentary side compressor towards the mobile refrigerant piping of senior side compressor₁And in senior side compressorDetected temperatures T₂In one or two the cold-producing medium that relatively judges whether flow through equal oily pipe arrangement.

In the heat pump of the second invention, preferably, in the time carrying out unsettled operation, even if it is various to open condition, control dressPut also and can indicate and continue to close equal fuel tap.

And, in the heat pump of the second invention, preferably in the time that the rotating speed of senior side compressor is less than the value of predetermining,Whether flow through the judgement of equal oily pipe arrangement regardless of cold-producing medium, control device all can indicate equal fuel tap alternately to repeat by certain hourOpen and close.

Using the 1st heat exchanger of the heat pump of the second invention described above as making cold-producing medium and water carry out heat exchangeAnd the heat-pump-type hot-warer supplying machine of water-refrigerant heat exchanger that water is heated is due to rudimentary side compressor and senior side pressure contractingMeasuring of the refrigerating machine oil of machine guaranteed, therefore can stably realize high efficiency hot water supply.

Invention effect

According to the first invention of the application, without the operation that stops rudimentary side compressor and senior side compressor, can be onlyRealize rudimentary side compressor and senior side compressor by this shirtsleeve operation of switching of the 1st magnetic valve and the 2nd magnetic valveIn the homogenising of refrigerating machine oil.

And, according to the second invention of the application, without the operation that stops compressing mechanism, and can be by equal fuel tapOpening/closing this shirtsleeve operation realizes the homogenising of the refrigerating machine oil between compressing mechanism. And, according to the present invention, if sentenceBreak as cold-producing medium flows through equal oily pipe arrangement, close the equal fuel tap of opening, therefore can avoid flowing through equal oily pipe arrangement because of cold-producing mediumAnd the loss of the compressing mechanism producing.

Brief description of the drawings

Fig. 1 is the figure that represents the loop structure of the related heat pump of the 1st embodiment.

Fig. 2 is the figure that represents the action of the heat pump of the 1st embodiment, and Fig. 2 (a) represents two-stage compression operation, Fig. 2(b) represent one-level compression operation.

Fig. 3 represents to utilize two magnetic valves to carry out the two-stage compression operation and one-level compression operation of the heat pump of Fig. 1Between the figure of loop structure of switching.

Fig. 4 is the figure that is attached with the loop structure of two oil eliminators in the heat pump of presentation graphs 1.

Fig. 5 is the figure that represents the loop structure of the supplying hot water/air conditioner of the related heat-pump-type of the 2nd embodiment.

Fig. 6 represents the loop structure of the supplying hot water/air conditioner of the related heat-pump-type of the 2nd embodiment, illustrate with Fig. 5 notSame operational mode.

Fig. 7 is the figure that represents the variation of equal oily pipe arrangement.

Fig. 8 is the figure that represents the loop structure of the related kind of refrigeration cycle of the 3rd embodiment.

Fig. 9 is the figure of the action of the kind of refrigeration cycle of presentation graphs 8, closes equal oily pipe arrangement in Fig. 9 (a), in figure (b), opens equal oilPipe arrangement.

Figure 10 is the flow chart that represents the switching order of the valve on the equal oily pipe arrangement of the kind of refrigeration cycle that is arranged at Fig. 8.

Figure 11 is the flow chart that represents the variation of the switching order of the valve of Figure 10.

Figure 12 is the figure that represents the loop structure of the supplying hot water/air conditioner of the related heat-pump-type of the 4th embodiment.

Figure 13 is the figure that represents the loop structure of the supplying hot water/air conditioner of the related heat-pump-type of the 4th embodiment, illustratesThe operational mode different from Figure 12.

Detailed description of the invention

Below, with reference to accompanying drawing, embodiments of the present invention are described.

[the 1st embodiment]

As shown in Figure 1, the related heat pump 1 of the 1st embodiment possesses: rudimentary side compressor 10a and senior side pressureContracting machine 10b, compresses and the cold-producing medium that spues; The 1st heat exchanger 11, makes the cold-producing medium being compressed by senior side compressor 10b and becomesThe fluid of the object of heat exchange carries out heat exchange; Expansion valve (following, to be only expansion valve) 12, makes to flow out from the 1st heat exchanger 11Cold-producing medium puffing; And the 2nd heat exchanger 13, the cold-producing medium that makes puffing in expansion valve 12 with become heat exchange pairThe fluid of elephant carries out heat exchange, and they are connected in series successively along the loop direction of cold-producing medium. In present embodiment, the 1st heat is handed overParallel operation 11 for example can be as by carrying out with water the condenser performance function that heat exchange is dispelled the heat, and, the 2nd heat exchanger 13Can be as by carrying out with outer gas the evaporimeter performance function that heat exchange is absorbed heat.

Heat pump 1 possesses the four-way of the connection status of following switching rudimentary side compressor 10a and senior side compressor 10bTransfer valve 14. , four-way switching valve 14 cold-producing medium by rudimentary side compressor 10a and senior side compressor 10b the twoTwo-stage compression operation (two-stage compression path) with cold-producing medium only by rudimentary side compressor 10a but roundabout senior side compressor 10bOne-level compression operation (one-level compressed path) between switch.

And heat pump 1 possesses refrigerating machine oil and the height for keeping equably rudimentary side compressor 10a to keepThe equal oil machine structure 20 of the oil mass of the refrigerating machine oil keeping in level side compressor 10b.

Heat pump 1 possess link rudimentary side compressor 10a and senior side compressor 10b pipe arrangement L1, link senior sidePipe arrangement L3, the company of pipe arrangement L2, link the 1st heat exchanger 11 and the 2nd heat exchanger 13 of compressor 10b and the 1st heat exchanger 11Tie the pipe arrangement L4 of the 2nd heat exchanger 13 and rudimentary side compressor 10a, form thus the refrigerant loop of refrigerant circulation. Wherein,For rudimentary side compressor 10a, pipe arrangement L4 forms suction side pipe arrangement, links rudimentary side compressor 10a and senior side pressure contractingThe pipe arrangement L1 of machine 10b forms intermediate pressure pipe arrangement, and for senior side compressor 10b, pipe arrangement L2 forms exhaust end pipe arrangement.

And heat pump 1 possesses the exhaust end (pipe arrangement L1) and the senior side compressor that link rudimentary side compressor 10aThe pipe arrangement L5 of the exhaust end (pipe arrangement L2) of 10b. Aforementioned four-way switching valve 14 is arranged at the telling of rudimentary side compressor 10a of pipe arrangement L5Go out the link of side. Four-way switching valve 14 is directly inhaled the cold-producing medium spuing from rudimentary side compressor 10a by pipe arrangement L1Enter to senior side pressure contracting machine 10b or by pipe arrangement L5, be supplied between the 1st heat exchanger 11 and carry out by pipe arrangement L2 againSwitch. By this switching, realize two-stage compression path and one-level compressed path) between switching.

In addition, sometimes do not distinguish rudimentary side compressor 10a and senior side compressor 10b and be referred to as compressing mechanism 10.

Then, heat pump 1 possesses oil eliminator 26 on pipe arrangement L2. Oil eliminator 26 is by oil return pipe arrangement 27 and seniorSide compressor 10b directly connects. Oil return pipe arrangement 27 possesses fixed restriction device 27a.

While carrying out two-stage compression operation, oil eliminator 26 divides from the cold-producing medium spuing from senior side compressor 10bFrom going out refrigerating machine oil, make it turn back to senior side compressor 10b via returning to pipe arrangement 27. While carrying out one-level compression operation,Oil eliminator 26 is isolated refrigerating machine oil from the cold-producing medium spuing from rudimentary side compressor 10a, makes it via oil return pipe arrangement 27Turn back to senior side compressor 10b.

Below, successively each constitutive requirements of heat pump 1 are described.

[compressing mechanism 10]

Rudimentary side compressor 10a is driven in rotation by the electro-motor that is configured to one, sucks and has passed through the 2nd thusThe cold-producing medium of the low-temp low-pressure of heat exchanger 13 is also compressed to intermediate pressure, spues towards senior side compressor 10b.

As the compressing mechanism that is applicable to rudimentary side compressor 10a, applicable Scrawl compressor structure, rotary compressorThe compressing mechanism of the known forms such as structure. Senior side compressor 10b is also identical.

Senior side compressor 10b sucks the cold-producing medium spuing from rudimentary side compressor 10a and compresses, high as high temperatureThe cold-producing medium of pressing spues towards the 1st heat exchanger 11.

[the 1st heat exchanger 11]

The 1st heat exchanger 11 is by making the fluid such as water, air of the object that becomes heat exchange and the cold-producing medium of HTHPCarrying out heat exchange heats this fluid. The cold-producing medium of the HTHP spuing from senior side compressor 10b here byCooling and condensation. The 1st heat exchanger 11 can use known heat exchanger. Then the 2nd heat exchanger 13 of explanation is also identical.

In the time that the object of heat exchange is air, on the 1st heat exchanger 11, set up Air Blast fan 11f, by Air Blast fan 11fThe air of air-supply carries out heat exchange with cold-producing medium in the process by the 1st heat exchanger 11.

[expansion valve 12, the 2nd heat exchanger 13]

The 2nd heat exchanger 13 is between the cold-producing medium and outer gas (wind pushing air) that are depressurized expansion by expansion valve 12Carry out the mechanism of heat exchange, in the process of this heat exchange, cold-producing medium evaporation absorbs heat from outer gas. The 2nd heat exchanger 13On also set up Air Blast fan 13f, the air of being blown by Air Blast fan 13f and cold-producing medium carry out heat exchange, make thus low compactingCryogen evaporates and generation heat-absorbing action.

Expansion valve 12 for example can use possesses the valve body of needle-like and for driving the expansion valve of impulse motor of valve body.

[all oil machine structures 20]

All oil machine structure 20 possess link rudimentary side compressor 10a and senior side compressor 10b equal oily pipe arrangement 21, link allThe bypass pipe arrangement 23 of oil pipe arrangement 21 and oil return pipe arrangement 27 and be arranged at the magnetic valve 25 of bypass pipe arrangement 23.

All oil machine structure 20 makes the equal oily pipe arrangement 21 of refrigerating machine oil process at rudimentary side compressor 10a and senior side compressor 10bBetween circulation. And all oil machine structure 20 makes refrigerating machine oil return from the exhaust end of senior side compressor 10b via bypass pipe arrangement 23To equal oily pipe arrangement 21. The function of this bypass pipe arrangement 23 is brought into play in the time carrying out one-level compression operation, thus equal oily pipe arrangement 21 is composedGive required differential pressure.

If will represent rudimentary side compressor 10a and the senior side compressor 10b oil level of the amount of required refrigerating machine oil separatelyAs benchmark, equal oily pipe arrangement 21 connects with rudimentary side compressor 10a and senior side compressor 10b directly over this benchmark oil levelConnect.

Fig. 1 illustrates the example that is provided with single equal oily pipe arrangement 21, as shown in Figure 7, can be set up in parallel multiple equal oily pipe arrangements 21(21A, 21B, 21C). And, on equal oily pipe arrangement 21B, 21C, open and close valve 22B, 22C are set respectively.

Multiple equal oily pipe arrangement 21A, 21B, 21C are so set, and by making open and close valve 22B, 22C carry out on-off action, pinTo flowing through excessive refrigeration machine oil condition sometimes in single equal oily pipe arrangement 21, can adjust the amount that refrigerating machine oil flows through.In addition, on equal oily pipe arrangement 21A, open and close valve also can be set.

In addition, the maximum that equal oily pipe arrangement 21A, the refrigerating machine oil of 21B, 21C flow through can be identical, also can be different. AndAnd the temperature that the switching of open and close valve 22B, 22C for example can flow into the refrigerating machine oil of senior side compressor 10b by sensing is enteredRow is controlled.

[action of heat pump 1]

Below, the action of heat pump 1 is described.

In heat pump 1, cold-producing medium circulates, and carries out two-stage compression operation. But, if possess specific condition,Carry out one-level compression operation.

First, to two-stage compression, operation describes.

When carrying out two-stage compression when operation, as shown in Fig. 2 (a), four-way switching valve 14 be switched to make pipe arrangement L1 (L11 andL12) be communicated with, be forced into the cold-producing medium of intermediate pressure by rudimentary side compressor 10a by pipe arrangement L11, four-way switching valve 14, pipe arrangementL12 is sucked into senior side compressor 10b. In Fig. 2 (a), arrow represents the direction that cold-producing medium flows through. Also phase of Fig. 2 described later (b)With.

Be compressed to the high-pressure refrigerant spuing after HTHP by senior side compressor 10b and flow into the 1st by pipe arrangement L2Heat exchanger 11, dispels the heat to heat exchange object. In the 1st heat exchanger 11, the high-pressure refrigerant of heat radiation is passing through pipe arrangement L3Afterwards by expanding and become low pressure refrigerant in the process of expansion valve 12. This low pressure refrigerant further flows into the by pipe arrangement L32 heat exchangers 13, from outdoor air heat absorption and evaporate. Thereafter the low pressure refrigerant flowing out from the 2nd heat exchanger 13, is by joiningPipe L4 is sucked into rudimentary side compressor 10a.

The low pressure refrigerant that is sucked into rudimentary side compressor 10a is compressed and after becoming intermediate pressure refrigerant, quiltSpue to pipe arrangement L1. Spued to the intermediate pressure refrigerant of pipe arrangement L1 and be sucked into senior side pressure from rudimentary side compressor 10aContracting machine 10b. The cold-producing medium that is sucked into senior side compressor 10b is compressed and spued to pipe arrangement after becoming high-pressure refrigerantL2。

Heat pump 1 is repeating the process of circulation of the compression of cold-producing medium described above, condensation, expansion and evaporationThe equal oily pipe arrangement 21 of middle process and make refrigerating machine oil circulation, thus by rudimentary side compressor 10a and senior side compressor 10b separatelyOil level level is guaranteed in required scope.

At this, turn back to the mode of compressor as refrigerating machine oil contained the cold-producing medium that makes to spue from compressor, oneAs be following mode, that is, and the exhaust end configuration of compressor by cold-producing medium and oily separate be known as establishing of oil eliminatorStandby, make isolated refrigerating machine oil turn back to the suction of compressor via the oil return circuit that possesses the fixed restriction devices such as capillarySide.

But, for example, if imagination is set the hot-warer supplying machine of heat-pump-type, because depending on, the high-pressure of equipment enters waterThe temperature (for example, the scope of 35～75 DEG C) of the water in refrigerant heat exchanger (water-refrigerant heat exchanger) and determining,Therefore the suction side of compressor and the pressure differential of exhaust end may significantly change because of water temperature. If in the heat exchange of water-cold-producing mediumUnder the lower state of the inlet water temperature of device, carry out two-stage compression operation, rudimentary side compressor 10a and senior side compressor 10b itBetween differential pressure diminish. According to the differential pressure of this compressor chamber, determine the amount of the refrigerating machine oil returning. Therefore, in present embodiment, justIn the time carrying out two-stage compression operation, if the differential pressure step-down between rudimentary side compressor 10a and senior side compressor 10b switchesBecome one-level compression operation, and open magnetic valve 25. So, heat pump 1 make refrigerating machine oil from oil eliminator 26 via bypassPipe arrangement 23, does not turn back to equal oily pipe arrangement 21 via senior side compressor 10b, the differential pressure in equal oil machine structure 20 can be begun thusGuarantee eventually for more than setting. And heat pump 1 can make oil not via the fixed restriction device being positioned on oil return pipe arrangement 2727a and senior side compressor 10b and turn back to rudimentary side compressor 10a, therefore prevent in fixed restriction device 27a or senior side pressureIn contracting machine 10b, produce the pressure loss and cause oil return flow to reduce.

While carrying out two-stage compression operation, if possess the condition of following (1)～(3), heat pump 1 switches to oneLevel compression operation. Following condition is the index of the differential pressure step-down between rudimentary side compressor 10a and senior side compressor 10b.The setting T of condition (1)～(3)_R、ΔP_R1And Δ P_R2Be not that monodrome is determined, but with each structure of applicable heat pump 1Become important document, service condition to determine accordingly. In addition, though the diagram of omission, water temperature T_W, suction pressure P_LI, pressure spuesP_LOAnd the pressure P that spues_HOBy being attached to temperature sensor in the 1st heat exchanger 11, being attached to rudimentary side compressor 10a, heightPressure sensor in level side compressor 10b detects. The information detecting is sent to the control device 30 shown in Fig. 1. ControlDevice 30 processed utilizes and the water temperature T of obtaining_W, suction pressure P_LI, pressure P spues_LOAnd the pressure P that spues_HORelevant information is sentencedFixed condition (1)～(3). While carrying out one-level compression operation, control device 30 also continues decision condition (1)～(3).

(1) enter the temperature of the water in water refrigerant heat exchanger (hydrothermal exchange): T_W, setting: T_R

T_W≤T_R

(2) the suction pressure P of rudimentary side compressor 10a_LI, the pressure P that spues of senior side compressor 10b_HO, setting: ΔP_R1

(P_HO-P_LI)≤ΔP_R1

(3) the suction pressure P of rudimentary side compressor 10a_LI, pressure P spues_LO, setting: Δ P_R2

(P_LO-P_LI)≤ΔP_R2

[two-stage compression operation → one-level compression operation]

While carrying out two-stage compression operation, any one in (1)～(3) if control device 30 is judged to be to satisfy conditionIndividual, indicate the position that four-way switching valve 14 is switched to the one-level compression operation shown in Fig. 2 (b). And, control device 30 fingersShow and open magnetic valve 25. Thus, heat pump 1 moves as follows.

Be compressed to the high-pressure refrigerant spuing after high pressure by rudimentary side compressor 10a by pipe arrangement L11, four-way switching valve14 and pipe arrangement L5 flow into the 1st heat exchanger 11, heat exchange object is dispelled the heat. In addition, at this, rudimentary side compressor 10a ratioTwo-stage compression when operation further improve service ability and by refrigerant compression to high pressure. And senior side compressor 10b stopsOperation.

In the 1st heat exchanger 11 high-pressure refrigerant of heat radiation by after pipe arrangement L3 by swollen in the process of expansion valve 12Swollen and become low pressure refrigerant. This low pressure refrigerant further flows into the 2nd heat exchanger 13 by pipe arrangement L3, from outdoor airAbsorb heat and evaporate. Thereafter the low pressure refrigerant flowing out from the 2nd heat exchanger 13, is sucked into rudimentary side compressor by pipe arrangement L410a。

One-level compression operates in the circulation of the compression, condensation, expansion and the evaporation that repeat cold-producing medium described aboveIn process, magnetic valve 25 is being opened, and therefore refrigerating machine oil, by bypass pipe arrangement 23, does not return via senior side compressor 10bGet back to equal oily pipe arrangement 21. Therefore,, more than the differential pressure in equal oil machine structure 20 can being remained to setting, therefore can make lowOil level between level side compressor 10a and senior side compressor 10b keeps balance well.

Heat pump 1 described above uses four-way while switching between two-stage compression operation and one-level compression operationTransfer valve 14, but the present invention is not limited thereto. As shown in Figure 3, heat pump 2 also can by by two magnetic valve 14a,14b is disposed at respectively pipe arrangement L1, L5 and Selective Control switching is carried out between two-stage compression operation and one-level compression moveSwitch. In the case of the example shown in Fig. 3, if open magnetic valve 14a and shut electromagnetic valve 14b, carry out two-stage compressionOperation, if shut electromagnetic valve 14a and open magnetic valve 14b carries out two-stage compression operation. In addition, in Fig. 3, to Fig. 1The identical important document mark symbol identical with Fig. 1. Fig. 4 is also identical.

Fig. 1 illustrates oil eliminator 26 and rudimentary side compressor 10a and senior side compressor 10b, and the two is corresponding and arrangeExample, but heat pump 3 is as shown in Figure 4 such, can be also four-way switching valve at the exhaust end of rudimentary side compressor 10a14 dead ahead possesses the oil eliminator 28 that rudimentary side compressor 10a uses. Oil eliminator 28 is linked to all by oil return pipe arrangement 29Oil pipe arrangement 21.

Carrying out in operating any one the process of two-stage compression operation and one-level compression, oil eliminator 26 also canFrom the cold-producing medium spuing from rudimentary side compressor 10a, isolate refrigerating machine oil, make it via oil return pipe arrangement 29 and equal oily pipe arrangement21 turn back to rudimentary side compressor 10a. Therefore, can effectively to make refrigerating machine oil turn back to rudimentary for the heat pump 3 shown in Fig. 4Side compressor 10a.

[the 2nd embodiment]

Below, the supplying hot water/air conditioner of heat-pump-type of the heat pump 1 illustrating as the 1st embodiment will be suitable for100 describe as the 2nd embodiment of the present invention.

As shown in Figure 5, supplying hot water/air conditioner 100 is made up of heat pump 200 and water system 300.

[heat pump 200]

Heat pump 200 is to utilize to be only provided with the oil shown in the heat pump 1 (Fig. 1) illustrating in the 1st embodimentThe heat pump in the loop of separator 26 carries out heat exchange between outdoor air (outer gas) and cold-producing medium. Work as heat pump200 while there is the important document corresponding with heat pump 1, mark the symbol identical with the 1st embodiment, and the description thereof will be omitted. ButThat the 1st heat exchanger 11 is replaced by water-refrigerant heat exchanger 11. Water-refrigerant heat exchanger 11 is by making water systemThe water of 300 sides and cold-producing medium carry out heat exchange and water are heated. And the 2nd heat exchanger 13 is replaced by heat source side skyGas-heat exchanger 13. In addition, heat pump 200 comprises the following important document that heat pump 1 does not possess.

Heat pump 200 is in the suction side of pipe arrangement L2 and the rudimentary side compressor 10a of the exhaust end of senior side compressor 10bPipe arrangement L4 between possess four-way switching valve 15, make the loop direction of cold-producing medium reversible by this four-way switching valve 15, Neng GouxuanSelect any one in kind of refrigeration cycle (defrost cycle) and heating circulation, in described kind of refrigeration cycle, make cold-producing medium through thermal sourceSide air heat exchanger 13 circulates along clockwise direction to water-refrigerant heat exchanger 11, in described heating circulation, makes refrigerationAgent circulates in the counterclockwise direction through water-refrigerant heat exchanger 11 thermotropism source air heat exchangers 13.

Heat pump 200 is except heat source side air heat exchanger 13, water-refrigerant heat exchanger 11 and four-way switching valve 15In addition, on refrigerant loop, also possesses the conduct decompression of the outlet side refrigerant temperature of control water-refrigerant heat exchanger 11The 1st expansion valve 12a of mechanism, to cold-producing medium carry out gas-liquid separation intermediate pressure container 16a, cross cold line circle 17, centre pressedThe 2nd expansion valve 12b and reservoir 18 that power cold-producing medium reduces pressure. Reservoir 18 is isolated in heat source side air heat exchangeThe liquid cold-producing medium not being evaporated in device 13.

And heat pump 200 possesses and has magnetic valve 16b, the spray circuits 16 of check-valves 16c and playpipe 16d, shouldMagnetic valve is sucked into senior side pressure and contracts being injected into by the refrigerant gas of the isolated intermediate pressure of intermediate pressure container 16aIn the refrigerant gas of the intermediate pressure of machine 10b.

In addition, when magnetic valve 16b is for example full of the starting of liquid refrigerant in the inside of intermediate pressure container 16a, forPrevent that liquid refrigerant is supplied to senior side compressor 10b, also performance is as the effect of the valve of sealing spray circuits 16.

And heat pump 200 possesses the secondary pipe arrangement 121 arranged side by side with equal oily pipe arrangement 21, this pair pipe arrangement 121 possesses magnetic valve122. Similarly, heat pump 200 possesses the secondary pipe arrangement 127 arranged side by side with returning to pipe arrangement 27, and this pair pipe arrangement 127 possesses magnetic valve128. In addition, secondary pipe arrangement 121,127 all possesses flow controller.

Secondary pipe arrangement 121,127 owing to flowing through equal oily pipe arrangement 21, the amount of refrigerating machine oil of returning to pipe arrangement 27 is limited, therefore thinkingWhen more refrigerating machine oil is flowed, open magnetic valve 122,128.

[water system 300]

Water system 300 possesses Warm water circulation stream 301, and in this Warm water circulation stream, the water circulating via pump 307 is being establishedWater-the refrigerant heat exchanger 11 that is placed in heat pump 200 becomes warm water from cold-producing medium heat absorption, by making this warm waterAnd the radiator (utilizing side heat exchanger) 303 of load-side between circulate and carry out profit as heating thermal source etc.With. On this Warm water circulation stream 301, be connected with heat-accumulator tank 305, warm water is via the three-way switch valve 306 of flow rate adjustable ratioImport to this heat-accumulator tank from Warm water circulation stream 301, this heat-accumulator tank can store this warm water as accumulation of heat warm water.

The warm water that heat-accumulator tank 305 circulates to radiator 303 via the warm water that makes to be heated by water-refrigerant heat exchanger 11 followsSet three-way switch valve 306 in circulation road 301, accumulation of heat warm water is got by portion from it, flows to Warm water circulation in the moment of needsBe sidelong out on road 301.

And, in heat-accumulator tank 305, be provided with to supply with and utilize by the heat of the accumulation of heat warm water of hot water storage and heated heat supplyThe health water supply circuit (omitting diagram) of the warm water that water is used, the electric heater (omitting diagram) of energising as required.

Water system 300 is configured to as follows as constructed as above: can select by the switching of controlling three-way switch valve 306Select switching, thereby selecting to implement supplies with the heating operation of warm water or supplies with the accumulation of heat fortune of warm water to heat-accumulator tank 305 to radiator 303Any one in row, or, can be by utilizing temperature to radiator 303 and heat-accumulator tank 305 these two distribution supply warm waterWater is implemented these two kinds of heating operation and regenerative operations simultaneously.

And in water system 300, the water as heating target of being supplied with by water-circulating pump 307 by heat-accumulator tank 305 passes throughIn water-refrigerant heat exchanger 11, carry out heat exchange and be heated with the cold-producing medium of heat pump 200.

On the other hand, if select heating circulation in heat pump 200, the gas refrigerant of low-temp low-pressure is by compressorStructure 10 (rudimentary side compressor 10a, senior side compressor 10b) compression, spued as the gas refrigerant of HTHP toHeat pump 200. This gas refrigerant, as shown in the solid arrow in Fig. 5, is fed to water-refrigeration by four-way switching valve 14Agent heat exchanger 11 and along clockwise direction circulation. Now, water-refrigerant heat exchanger 11 is to make by water-circulating pump 307The water of the water system 300 of circulation and the heat exchanger that high-temperature high-pressure gas refrigerant carries out heat exchange, by the condensation of cold-producing mediumAnd the condensation heat of heat radiation is as the condenser performance function that water is heated. Its result, the high temperature that flows through heat pump 200 is highThe gas refrigerant condensation of pressing and become the liquid refrigerant of HTHP, the water that flows through water system 300 absorbs heat from cold-producing mediumAnd become warm water.

Flowing into intermediate pressure by the cold-producing medium of water-refrigerant heat exchanger 11 condensations by the 1st expansion valve 12a of standard-sized sheet holdsDevice 16a. In this intermediate pressure container 16a, carry out the gas-liquid separation of cold-producing medium, and the gas system of isolated intermediate pressureCryogen is injected by magnetic valve 16b, check-valves 16c is centre between rudimentary side compressor 10a and senior side compressor 10bPressure.

On the other hand, by the cold-producing medium of the isolated liquid state of intermediate pressure container 16a via crossing cold line circle 17, by the 2ndExpansion valve 12b and being depressurized, thus the cold-producing medium of the gas-liquid two-phase of low-temp low-pressure become, be fed to heat source side air heat exchangeDevice 13. Be fed to as the gas-liquid two-phase cold-producing medium of the heat source side air heat exchanger 13 of evaporimeter performance function by with outwardGas carries out heat exchange and from outer gas, absorbs heat and gasify.

So, by heat source side air heat exchanger 13, heat absorption from outer gas and the gas refrigeration of low-temp low-pressure of gasificationAgent is attracted to rudimentary side compressor 10a through four-way switching valve 15 again. So be attracted to the low of rudimentary side compressor 10aThe gas refrigerant of temperature low pressure compresses in order and becomes HTHP through rudimentary side compressor 10a and senior side compressor 10bGas refrigerant, circulation in following identical path and repeat the state variation of gas-liquid. Now, airborne moistureDeng likely become low temperature heat source side air heat exchanger 13 outer peripheral face freeze and produce frost.

Frosting meeting hinders the heat exchange of cold-producing medium in heat source side air heat exchanger 13 and outer gas and can make heat exchange imitateRate reduces, and therefore needing has frostless accumulation to remove by implementing Defrost operation each suitable running time by sensingFrost. This Defrost operation carries out as follows in above-mentioned heat pump 200, that is, switch four-way switching valve 15 and make the circulation of cold-producing mediumDirection reverses, and makes the kind of refrigeration cycle (defrost cycle) of cold-producing medium to the direction circulation of the dotted arrow in Fig. 6 thereby switch to, willThe gas refrigerant of the HTHP spuing from senior side compressor 10b imports heat source side air heat exchanger 13, utilizes it looseThe frost that heat (condensation heat) makes to be attached on heat source side air heat exchanger 13 melts.

In the time carrying out Defrost operation based on this recycled back mode, water-refrigerant heat exchanger 11 can be sent out as evaporimeterWave function, heat absorption from flow through the water of Warm water circulation stream 301 and make cold-producing medium gasification, utilizes this heat and makes frosting in heat source sideFrost on air heat exchanger 13 melts. Now, if water temperature excessively reduces, water is interior icing in water-refrigerant heat exchanger 11,Can produce the risk of heat exchanger breakage. Therefore,, in the time defrosting, need to prevent from following in water-refrigerant heat exchanger 11The water temperature of ring and the evaporating temperature of cold-producing medium excessively reduce.

In supplying hot water/air conditioner 100 described above, also with the 1st embodiment similarly, if carrying out secondary pressureWhen contracting operation, possess the condition of following (1)～(3), switch to one-level compression operation. This switching is as with reference to figure 2 (a), (b)Illustrated.

T_W≤T_R

(P_HO-P_LI)≤ΔP_R1

(P_LO-P_LI)≤ΔP_R2

[two-stage compression operation → one-level compression operation]

If be switched to one-level compression operation, be compressed to by rudimentary side compressor 10a the height spuing after high pressure and suppressCryogen flows into water-refrigerant heat exchanger 11 by pipe arrangement L11, four-way switching valve 14 and pipe arrangement L5, and heat exchange object is carried outHeat radiation. In addition, at this, when rudimentary side compressor 10a moves than two-stage compression, further improve service ability and cold-producing medium is pressedBe reduced to high pressure. And senior side compressor 10b is out of service.

[the 3rd embodiment]

As shown in Figure 8, the related heat pump 4 of the 3rd embodiment possesses: rudimentary side compressor 10a and senior side pressureContracting machine 10b, compresses and the cold-producing medium that spues; The 1st heat exchanger 11, makes the cold-producing medium being compressed by senior side compressor 10b and becomesThe fluid of the object of heat exchange carries out heat exchange; Expansion valve 12, makes the cold-producing medium puffing flowing out from the 1st heat exchanger 11;And the 2nd heat exchanger 13, make the cold-producing medium of puffing in expansion valve 12 and the fluid of the object that becomes heat exchange carry out heatExchange, they are connected in series successively along the loop direction of cold-producing medium. In present embodiment, the 1st heat exchanger 11 for example canAs by carrying out with water the condenser performance function that heat exchange is dispelled the heat, and, the 2nd heat exchanger 13 can serve as by withOuter gas carries out heat exchange and the evaporimeter performance function of absorbing heat.

Heat pump 4 possesses refrigerating machine oil and the senior side for keeping equably rudimentary side compressor 10a to keepThe equal oil machine structure 20 of the oil mass of the refrigerating machine oil keeping in compressor 10b. As the equal oil machine structure of the feature of present embodiment20 detailed description will be in aftermentioned.

Heat pump 4 possess link rudimentary side compressor 10a and senior side compressor 10b pipe arrangement L1, link senior sidePipe arrangement L3, the company of pipe arrangement L2, link the 1st heat exchanger 11 and the 2nd heat exchanger 13 of compressor 10b and the 1st heat exchanger 11Tie the pipe arrangement L4 of the 2nd heat exchanger 13 and rudimentary side compressor 10a, form thus the refrigerant loop of refrigerant circulation. Wherein,For rudimentary side compressor 10a, pipe arrangement L4 forms suction side pipe arrangement, links rudimentary side compressor 10a and senior side pressure contractingThe pipe arrangement L1 of machine 10b forms intermediate pressure pipe arrangement, and for senior side compressor 10b, pipe arrangement L2 forms exhaust end pipe arrangement.

Below, each constitutive requirements of heat pump 4 are described successively.

[compressing mechanism 10]

[the 1st heat exchanger 11]

[expansion valve 12, the 2nd heat exchanger 13]

The 2nd heat exchanger 13 is to carry out heat exchange being depressurized by expansion valve 12 between the cold-producing medium of expansion and outer gasMechanism, in the process of this heat exchange, cold-producing medium evaporation absorbs heat from outer gas. On the 2nd heat exchanger 13, also set upAir Blast fan 13f, the air of being blown by Air Blast fan 13f and cold-producing medium carry out heat exchange, make thus low pressure refrigerant evaporation andProduce heat-absorbing action.

Expansion valve 12 is for example by possessing the valve body of needle-like and forming for the electric expansion valve of the impulse motor that drives valve body.

[all oil machine structures 20]

All oil machine structure 20 possesses: equal oily pipe arrangement 21, links rudimentary side compressor 10a and senior side compressor 10b; All fuel taps(open and close valve) 23, is arranged at equal oily pipe arrangement 21, controls the refrigeration machine between rudimentary side compressor 10a and senior side compressor 10bFlowing of oil; The 1st temperature sensor 34, with close setting of equal oily pipe arrangement 21, for detection of the temperature of equal oily pipe arrangement 21 inside; AndThe 2nd temperature sensor 35, arranges with pipe arrangement L2 is close, for detection of the temperature of pipe arrangement L2 inside.

Each temperature information (detected temperatures) T being detected by the 1st temperature sensor 34 and the 2nd temperature sensor 35₀,T₁QuiltBe sent to control device 30. Control device 30 is according to the temperature information T transmitting₀、T₁Control the opening/closing of equal fuel tap 23.

By controlling the opening/closing of equal fuel tap 23, all oil machine structure 20 supplies remaining refrigerating machine oil in senior side compressor 10bBe given to rudimentary side compressor 10a or stop supplying with.

Rudimentary side compressor 10a and senior side compressor 10b are set with respectively and represent the required refrigerating machine oil of normal operationThe benchmark oil level of amount, equal oily pipe arrangement 21 is connected in rudimentary side compressor 10a, senior on the position corresponding with benchmark oil levelSide compressor 10b. And preferably each link of equal oily pipe arrangement 21 is soaked in refrigerating machine oil all the time.

As shown in Fig. 9 (b), if open the equal fuel tap 23 of equal oily pipe arrangement 21, refrigerating machine oil is from senior side compressor 10b courtFlow through to rudimentary side compressor 10a. This be because the pressure of senior side compressor 10b inside higher than in rudimentary side compressor 10aThe pressure of portion. In addition, in Fig. 9, blacking represents the equal fuel tap 23 (Fig. 9 (a)) of closing, the equal fuel tap 23 that hollow expression is being opened(Fig. 9 (b). And, in Fig. 9, in the time that refrigerating machine oil flows through, represent equal oily pipe arrangement 21 with solid line, in the time that refrigerating machine oil does not flow through,Dot.

But the prerequisite that refrigerating machine oil flows through towards rudimentary side compressor 10a from senior side compressor 10b is senior side pressureThe link of the equal oily pipe arrangement 21 in contracting machine 10b is soaked in refrigerating machine oil. If not this prerequisite, equal oily pipe arrangement 21 can becomeThe passage of cold-producing medium. Thus, a part for the cold-producing medium being compressed by senior side compressor 10b is towards rudimentary side compressor10a is reverse to be returned. This means the power of rudimentary side compressor 10a and senior side compressor 10b compressed refrigerant in the twoBe depleted. Therefore,, in the time that refrigerating machine oil does not flow through equal oily pipe arrangement 21, as shown in Fig. 9 (a), preferably close equal fuel tap 23 and sealClose equal oily pipe arrangement 21, in order to avoid the rudimentary side compressor of refrigerant flow direction 10a.

[control device 30]

Control device 30 is arranged the action of heat pump 4, especially in the present embodiment, controls the equal oil of equal oily pipe arrangement 21Valve 23 opening/closing. Control device 30 in order to control the opening/closing of equal fuel tap 23 from the 1st temperature sensor 34 and the 2nd TEMPDevice 35 obtains respectively temperature information T₀、T₁. Control device 30 is by the temperature information T relatively obtaining₀、T₁Judge equal fuel tap23 opening/closing. , if relatively flow through the refrigerating machine oil of equal oily pipe arrangement 21 and flow through the temperature of cold-producing medium of pipe arrangement L2, refrigerationThe temperature of agent is obviously lower. But, if what flow through in equal oily pipe arrangement 21 is cold-producing medium instead of refrigerating machine oil, equal oily pipe arrangement 21The temperature information T of middle detection₀With the temperature information T detecting in pipe arrangement L2₁Difference diminish. Therefore, if control device 30 C.TsInformation T₀With temperature information T₁, can judge that what in equal oily pipe arrangement 21, flow through is refrigerating machine oil or cold-producing medium.

[action of heat pump 4]

Below, the action of heat pump 4 is described.

In heat pump 4, refrigerant circulation, and carry out two-stage compression kind of refrigeration cycle.

In heat pump 4, the cold-producing medium of the HTHP spuing from senior side compressor 10b flows into the 1st by pipe arrangement L2Heat exchanger 11, dispels the heat to exchangeable object. In 1 heat exchanger 11, the cold-producing medium of heat radiation is swollen by passing through after pipe arrangement L3In the process of swollen valve 12, expand and become low pressure refrigerant. This low pressure refrigerant further flows into the 2nd heat exchange by pipe arrangement L3Device 13, from outdoor air heat absorption and evaporate. Thereafter the low pressure refrigerant flowing out from the 2nd heat exchanger 13, is by pipe arrangement L4 quiltBe sucked into rudimentary side compressor 10a.

The low pressure refrigerant that is sucked into rudimentary side compressor 10a is compressed and become quilt after the cold-producing medium of intermediate pressureSpue to pipe arrangement L1. The cold-producing medium being spued to the intermediate pressure of pipe arrangement L1 from rudimentary side compressor 10a is sucked into senior sideCompressor 10b. The cold-producing medium that is sucked into senior side compressor 10b is compressed and after becoming high-pressure refrigerant, spued toPipe arrangement L2.

Heat pump 4 is repeating the process of circulation of the compression of cold-producing medium described above, condensation, expansion and evaporationIn alternately repeat equal fuel tap 23 at closed period t_wClose and during equal oil t_mThe action of opening. Present embodiment hasEven t during equal oil_mAlso the feature of the equal fuel tap 23 of positive closing. Below, the on-off action to equal fuel tap 23 with reference to Figure 10Order describes.

As shown in figure 10, the initial setting starting as the operation of instruction heat pump 4, control device 30 instructions are closed(OFF) equal fuel tap 23 (Figure 10 S101). When all fuel tap 23 is closed from the beginning, continue to keep this state.

Control device 30 timing self-indications move the elapsed time t having started, if this elapsed time t reaches and predeterminesClosed period t_w, (ON) all fuel taps 23 (Figure 10 S103) are opened in instruction. Reach afterwards rule in advance if indicate equal fuel tap 23 to openT during fixed equal oil_m, equal fuel tap 23 (Figure 10 S111) is closed in control device 30 instructions. As more than, the 1st embodiment allFuel tap 23 alternately repeats at closed period t_wClose and during equal oil t_mThe action of opening.

But about the switching of equal fuel tap 23, control device 30 is set with two kinds of exceptions of following explanation.

First, control device 30 judges whether stable operation of heat pump 4, in the time of stable operation, is transitioned into second exampleOuter judgement (step 105 be, S107), but in the time of astable operation, keep closing the state (Figure 10 S105 is no) of equal fuel tap 23.At this, the astable operation that is not equivalent to stable operation refers to while being for example equivalent to carry out Defrost operation. This is because this is non-steadyDetermine run duration, flow through the temperature of refrigerating machine oil of equal fuel tap 23 higher than the cold-producing medium that is sucked into senior side compressor 10bThe prerequisite of this present embodiment of temperature is likely false. And, during the starting initial stage of heat pump 4, be also equivalent to non-steadyFixed operation, but in present embodiment, this starting initial stage is counted as aforesaid closed period t_w。

Then, as second exception, the rotating speed R of the advanced side compressor of control device 30 10b and predeterminingRotating speed R₀(Figure 10 S107), when rotating speed R is less than rotating speed R₀Time, indicate equal fuel tap 23 alternately to repeat at regular intervals to openAnd close (OFF) (Figure 10 S107 be, S108) (ON).

If be not equivalent to above two exceptions, equal fuel tap 23 (Figure 10 S109) is opened in control device 30 instructions. All fuel tapsAfter 23 these instructions of reception, only t during equal oil_mMaintain open mode (Fig. 3 S111).

Control device 30 is judging the temperature information T obtaining from the 1st temperature sensor 34 during this period₀With from the 2nd temperature passThe temperature information T that sensor 35 obtains₁Difference (T₀-T₁) whether be the value Δ T following (Figure 10 S113) predetermining. At this, temperatureDegree information T₀Be regarded as flowing through the temperature of the fluid (refrigerating machine oil or cold-producing medium) of equal oily pipe arrangement 21, temperature information T₁Be regarded as byBe sucked into the temperature of the cold-producing medium of senior side compressor 10b.

If above-mentioned difference (T₀-T₁) be below Δ T, control device 30 be judged as in equal oily pipe arrangement 21, flow through be refrigerationAgent instead of refrigerating machine oil, and close equal fuel tap 23 (Figure 10 S113 is). On the other hand, if above-mentioned difference (T₀-T₁) exceed Δ T,All fuel tap 23 continues to open to t during equal oil_mExpire, if t during equal oil_mAt the expiration, all fuel tap 23 is closed (Figure 10 S113No, S111 is).

As described above, according to present embodiment, without stopping rudimentary side compressor 10a and senior side compressor 10bOperation, and can come to supply with refrigerating machine oil from the rudimentary side of senior side direction by the opening/closing this shirtsleeve operation of equal fuel tap 23, fromAnd realize the homogenising of both refrigerating machine oils. And, according to present embodiment, if control device 30 is judged as equal oily pipe arrangement 21In what flow through is cold-producing medium instead of refrigerating machine oil, close equal fuel tap 23, therefore can avoid joining because cold-producing medium flows through equal oilPipe 21 and the loss of compressing mechanism 10 that produces.

Above, describe the present invention according to embodiment, but only otherwise depart from aim of the present invention, can accept or rejectSelect the structure of enumerating in above-mentioned embodiment or suitably change to other structures.

Above, according to closed period t_wWith t during equal oil_mThe principle of controlling equal fuel tap 23 opens and closes, but the present invention is notBe limited to this. As the condition of opening equal fuel tap 23, also can utilize temperature information T₀、T₁. That is, as shown in figure 11, also can be at T₀-T₁While exceeding Δ T, open equal fuel tap 23 (Figure 11 step 203, step 109), at T₀-T₁For in time below Δ T, is closed equal fuel tap 23 (figure11 steps 113, S101).

And, with temperature information T₀The temperature information of making comparisons is not limited to temperature information T₁, also can contract with senior side pressureDetected temperatures (temperature information) T in machine 10b₂Make comparisons. The difference of now obtaining is T₂-T₀If this difference is what predetermineBelow value Δ TT, control device 30 is judged as cold-producing medium and flows through equal oily pipe arrangement 21. In addition, the temperature in senior side compressor 10bDegree store refrigerating machine oil below be detected.

[the 4th embodiment]

Below, the supplying hot water/air conditioner of heat-pump-type of the heat pump 4 illustrating as the 1st embodiment will be suitable for100 describe as the 4th embodiment of the present invention.

As shown in FIG. 12 and 13, supplying hot water/air conditioner 100 is made up of heat pump 200 and water system 300.

[heat pump 200]

Heat pump 200 utilizes the heat pump 4 illustrating in the 1st embodiment, in outdoor air (outer gas) and refrigerationBetween agent, carry out heat exchange. In the time there is the important document corresponding with heat pump 4, mark the symbol identical with the 3rd embodiment,And the description thereof will be omitted. But the 1st heat exchanger 11 is replaced by water-refrigerant heat exchanger 11. Water-refrigerant heat exchanger11 are carried out heat exchange and water are heated by the water and the cold-producing medium that make water system 300 sides. And, the 2nd heat exchanger 13 quiltsReplace to heat source side air heat exchanger 13. In addition, heat pump 200 comprises the following important document that heat pump 4 does not possess.

Heat pump 200 is in the suction side of pipe arrangement L2 and the rudimentary side compressor 10a of the exhaust end of senior side compressor 10bPipe arrangement L4 between possess four-way switching valve 15, make the loop direction of cold-producing medium reversible by this four-way switching valve 15, Neng GouxuanSelect any one in kind of refrigeration cycle (defrost cycle) and heating circulation, in described kind of refrigeration cycle, make cold-producing medium through thermal sourceSide air heat exchanger 13 circulates along clockwise direction to water-refrigerant heat exchanger 11, in described heating circulation, makes refrigerationAgent circulates in the counterclockwise direction through described water-refrigerant heat exchanger 11 thermotropism source air heat exchangers 13.

Heat pump 200 is except heat source side air heat exchanger 13, water-refrigerant heat exchanger 11 and four-way switching valve 15In addition, be also provided with as the cooling expansion valve 12a of flow controller mechanism, heating expansion valve 12b and container 39. This is cooling swollenSwollen valve 12a and heating expansion valve 12b are across container 18 arranged in series.

And heat pump 200 is provided with economizer 36 on pipe arrangement L3. Economizer 36 possesses heat for saverInterchanger 36a, saver expansion valve 36b and playpipe 36c. Pass through the liquid refrigerant of water-refrigerant heat exchanger 11A part be fed to saver heat exchanger 36a with expansion valve 36b through saver, with the liquid system that flows through pipe arrangement L3Cryogen carries out heat exchange and after evaporating, makes this gas refrigerant be injected into rudimentary side compressor 10a with high via playpipe 36cThe pipe arrangement L1 of the intermediate pressure between level side compressor 10b.

And heat pump 200 possesses oil eliminator 37 at the exhaust end of rudimentary side compressor 10a, in senior side pressure contractingThe exhaust end of machine 10b possesses oil eliminator 38. Refrigerating machine oil contained the cold-producing medium spuing from rudimentary side compressor 10a is at oilIn separator 37, from cold-producing medium, be separated, and turn back to rudimentary side compressor 10a via returning to pipe arrangement 37L. Similarly, fromIn the cold-producing medium that senior side compressor 10b spues, contained refrigerating machine oil is separated in oil eliminator 38 from cold-producing medium,And turn back to senior side compressor 10b via returning to pipe arrangement 38L.

[water system 300]

Water system 300 possesses Warm water circulation stream 301, in this Warm water circulation stream, circulates via water-circulating pump 307Water absorbs heat and becomes warm water in the water-refrigerant heat exchanger 11 being arranged in heat pump 200 from cold-producing medium, by makingThis warm water and the radiator 303 of load-side between circulation and utilizing as heating thermal source etc. This Warm water circulation streamOn road 301, be connected with heat-accumulator tank 305, warm water via the three-way switch valve 306 of flow rate adjustable ratio from Warm water circulation stream 301Import in this heat-accumulator tank, this heat-accumulator tank can store this warm water as accumulation of heat warm water.

The warm water that heat-accumulator tank 305 circulates to radiator 303 via the warm water that makes to be heated by water-refrigerant heat exchanger 11 followsSet three-way switch valve 306 in circulation road 301, accumulation of heat warm water is got by portion from it, and in moment of needs to Warm water circulationStream 301 is sidelong out.

Water system 300 is configured to as follows as constructed as above: can be by selecting switching three-way transfer valve 306 to select to implementSupply with the heating operation of warm water or supply with any one in the regenerative operation of warm water to heat-accumulator tank 305 to radiator 303, orPerson, can be by utilize warm water to implement heating operation to radiator 303 and heat-accumulator tank 305 these two distribution supply warm water simultaneouslyAnd these two kinds of regenerative operations.

On the other hand, if select heating circulation in heat pump 200, the gas refrigerant of low-temp low-pressure is by compressorStructure 10 (rudimentary side compressor 10a, senior side compressor 10b) compression, spued as the gas refrigerant of HTHP toHeat pump 200. This gas refrigerant is fed to water-refrigeration by four-way switching valve 15 as shown in the solid arrow in Figure 12Agent heat exchanger 11, in the counterclockwise direction circulation. Now, water-refrigerant heat exchanger 11 is to make to circulate by water-circulating pump 307The water of water system 300 and the heat exchanger that high-temperature high-pressure gas refrigerant carries out heat exchange, fall apart by the condensation of cold-producing mediumThe condensation heat of heat is as the condenser performance function that water is heated. Its result, flows through the HTHP of heat pump 200Gas refrigerant condensation and become the liquid refrigerant of HTHP, the water that flows through water system 300 absorbs heat and forms from cold-producing mediumFor warm water.

Cold-producing medium by 11 condensations of water-refrigerant heat exchanger flows into container 39 by the cooling expansion valve 12a of standard-sized sheet.In this container 39, carry out the gas-liquid separation of cold-producing medium, and the adjustment of the refrigerant amount circulating. In the downstream of container 39Dispose the heating expansion valve 12b that the liquid refrigerant of HTHP is reduced pressure. Cold-producing medium is at heating expansion valve 12bIn pass through, the liquid refrigerant of HTHP is depressurized and becomes the gas-liquid two-phase cold-producing medium of low-temp low-pressure thus, and is imported intoTo heat source side air heat exchanger 13. Be fed to the gas-liquid as the heat source side air heat exchanger 13 of evaporimeter performance functionTwo-phase system cryogen absorbs heat and gasifies from outer gas by carrying out heat exchange with outer gas.

Cold-producing medium in frosting meeting obstruction heat source side air heat exchanger 13 and the heat exchange of outer gas, and can make heat exchange effectRate reduces, and therefore needing has frostless accumulation to remove by implementing Defrost operation each suitable running time by sensingFrost. This Defrost operation by carrying out as follows, that is, switches four-way switching valve 15 and makes cold-producing medium in above-mentioned heat pump 200Loop direction reverses, thereby switch to, cold-producing medium (is removed to the kind of refrigeration cycle of the dashdotted direction of arrow circulation of the list in Figure 13Frost circulation), the gas refrigerant of the HTHP spuing from senior side compressor 10b is imported to heat source side air heat exchanger13, the frost that utilizes its heat radiation (condensation heat) to make to be attached on heat source side air heat exchanger 13 melts.

In the time carrying out Defrost operation based on this recycled back mode, water-refrigerant heat exchanger 11 can be sent out as evaporimeterWave function, heat absorption from flow through the water of Warm water circulation stream 301 and make cold-producing medium gasification, utilizes this heat to make frosting in heat source sideFrost on air heat exchanger 13 melts. Now, if water temperature excessively reduces, water is interior icing in water-refrigerant heat exchanger 11,Can produce the risk of heat exchanger breakage. Therefore,, in the time defrosting, need to prevent from following in water-refrigerant heat exchanger 11The water temperature of ring and the evaporating temperature of cold-producing medium excessively reduce.

In supplying hot water/air conditioner 100 described above, also similarly control and be arranged at rudimentary side pressure with the 1st embodimentThe switching of the equal fuel tap 23 between contracting machine 10a and senior side compressor 10b. Therefore, according to the supplying hot water/air-conditioning of present embodimentMachine 100, without the operation that stops rudimentary side compressor 10a and senior side compressor 10b, and can be by the switching of equal fuel tap 23This shirtsleeve operation realizes the homogenising of the refrigerating machine oil in rudimentary side compressor 10a and senior side compressor 10b.

Above, describe the present invention according to embodiment, but only otherwise depart from aim of the present invention, can accept or rejectBe chosen in the structure of enumerating in above-mentioned embodiment mode or suitably change to other structures.

For example, the part except MIN important document in the present invention who, narrates in the 1st embodiment is arbitrarily.Therefore, also the present invention can be applicable to further possess the supplying hot water/air conditioner of indoor heat exchanger, on the contrary, also canBe applicable to the hot-warer supplying machine of the heat-pump-type that only possesses hot water storage function.

Symbol description

1,2,3,4-heat pump, the rudimentary side compressor of 10a-, the senior side compressor of 10b-, 11-the 1st heat exchanger, water-Refrigerant heat exchanger, 11f-Air Blast fan, 12-expansion valve, 12a-the 1st expansion valve, cooling expansion valve, 12b-the 2nd expandsValve, heating expansion valve, 13-the 2nd heat exchanger, heat source side air heat exchanger, 13f-Air Blast fan, 14,15-four-way switchValve, 14a, 14b-magnetic valve, 16-spray circuits, 16a-intermediate pressure container, 16b-magnetic valve, 16c-check-valves, 16d-spraysPipe, 17-crosses cold line circle, 18-reservoir, the equal oil machine structure of 20-, the equal oily pipe arrangement of 21-, the equal fuel tap of 23-, 25-magnetic valve, 26,28-oilSeparator, 27,29-oil return pipe arrangement, 30-control device, 34-the 1st temperature sensor, 35-the 2nd temperature sensor, 36-saverLoop, 36a-saver heat exchanger, 36b-saver expansion valve, 36c-playpipe, 37,38-oil eliminator, 37L,38L-returns to pipe arrangement, 39-container, 100-supplying hot water/air conditioner, 121, the secondary pipe arrangement of 127-, 122,128-magnetic valve, 200-heat pumpSystem, 300-water system, 301-Warm water circulation stream, 303-radiator, 305-heat-accumulator tank, 306-three-way switch valve, 307-waterCirculating pump, L1, L11, L12, L2, L3, L4, L5-pipe arrangement.

Claims (according to the amendment of the 19th article of treaty)

1. a heat pump, is characterized in that, possesses:

Compressing mechanism, possesses rudimentary side compressor and senior side compressor, compresses and the cold-producing medium that spues;

Oil eliminator, is arranged at the exhaust end of described senior side compressor;

The 1st heat exchanger, makes the described cold-producing medium and the heat exchange object that are compressed by described compressing mechanism carry out heat exchange;

Expansion valve, makes the described cold-producing medium puffing flowing out from described the 1st heat exchanger;

The 2nd heat exchanger, makes the cold-producing medium of puffing in described expansion valve and heat exchange object carry out heat exchange;

All oil circuit footpath, links described rudimentary side compressor and described senior side compressor, makes refrigerating machine oil in described rudimentary side pressureBetween contracting machine and described senior side compressor, circulate;

Master returns to pipe arrangement, links between described oil eliminator and the suction side of described senior side compressor;

Oil return path, links described master and returns to pipe arrangement and described equal oil circuit footpath;

Oil return open and close valve, is arranged at described oil return path; And

Refrigerant path switching mechanism, makes described cold-producing medium flow through successively described rudimentary side compressor and described senior side pressure contractingThe two-stage compression path of machine and any one the one-level only flowing through in described rudimentary side compressor and described senior side compressorBetween compressed path, selectively switch,

If select described one-level compressed path, described refrigerant path switching mechanism is by opening described oil return open and close valve,Make not return via described oil return path via described senior side compressor from the described refrigerating machine oil of described oil eliminatorTo described equal oil circuit footpath.

2. heat pump according to claim 1, wherein,

If in the time having selected the state in described two-stage compression path, appointing in (the 1)～condition that meets the following conditions (3)One, the path of described cold-producing medium is switched to described one-level compressed path,

Condition (1): T_W≤T_R

T_W: in the time that the heat exchange object of the 1st heat exchanger is water, enter in the water refrigerant heat exchanger of carrying out hydrothermal exchangeThe temperature of water, T_R: setting;

Condition (2): (P_HO-P_LI)≤ΔP_R1

P_LI: the suction pressure of rudimentary side compressor, P_HO: the pressure that spues of senior side compressor, setting: Δ P_R1；

Condition (3): (P_LO-P_LI)≤ΔP_R2

P_LI: the suction pressure of rudimentary side compressor, P_LO: the pressure that spues of rudimentary side compressor, setting: Δ P_R2。

3. heat pump according to claim 1 and 2, wherein,

According to the system of the prediction in the amount of the refrigerating machine oil of the prediction in described rudimentary side compressor and described senior side compressorThe amount of cold machine oil is returned with the switching of open and close valve and the switching of described equal oil open and close valve described in controlling.

4. a heat-pump-type hot-warer supplying machine, is characterized in that,

Described the 1st heat exchanger of the heat pump in claims 1 to 3 described in any one is handed over for making cold-producing medium and water carry out heatWater-the refrigerant heat exchanger of changing and water is heated.

5. a heat pump, is characterized in that, possesses:

The 1st heat exchanger, the described cold-producing medium and the heat exchange object that are compressed by described compressing mechanism carry out heat exchange;

The 2nd heat exchanger, in described expansion valve, the described cold-producing medium of puffing and heat exchange object carry out heat exchange;

Equal oily pipe arrangement, links described rudimentary side compressor and described senior side compressor, makes refrigerating machine oil in described rudimentary side pressureBetween contracting machine and described senior side compressor, circulate;

All fuel tap, opens and closes described equal oily pipe arrangement; And

Control device, controls the on-off action of described equal fuel tap,

Flow through described equal oily pipe arrangement if described control device is judged as described cold-producing medium, the described equal oil of opening is closed in instructionValve.

6. heat pump according to claim 5, wherein,

Described control device is according to the detected temperatures T in described equal oily pipe arrangement₀With make described cold-producing medium from described rudimentary side compressorDetected temperatures T in the mobile refrigerant piping of described senior side compressor₁And detection in described senior side compressorTemperature T₂In one or two the described cold-producing medium that relatively judges whether flow through described equal oily pipe arrangement.

7. according to the heat pump described in claim 5 or 6, wherein,

In the time carrying out unsettled operation, even if it is various to open condition, described control device also can indicate continue to close described allFuel tap.

8. according to the heat pump described in any one in claim 5 to 6, wherein,

In the time that the rotating speed of described senior side compressor is less than the value of predetermining, no matter whether described cold-producing medium flows through described equal oilThe described judgement of pipe arrangement how, and described control device all can indicate described equal fuel tap alternately to repeat to open and close by certain hour.

9. a heat-pump-type hot-warer supplying machine, is characterized in that,

Described the 1st heat exchanger of the heat pump in claim 5 to 8 described in any one is handed over for making cold-producing medium and water carry out heatWater-the refrigerant heat exchanger of changing and water is heated.

Claims

1. a heat pump, is characterized in that, possesses:

Oil return open and close valve, is arranged at described oil return path; And

Refrigerant path switching mechanism, makes described cold-producing medium flow through successively described rudimentary side compressor and described senior side pressure contractingThe two-stage compression path of machine and any one the one-level only flowing through in described rudimentary side compressor and described senior side compressorBetween compressed path, selectively switch.

2. heat pump according to claim 1, wherein,

Condition (1): T_W≤T_R

Condition (2): (P_HO-P_LI)≤ΔP_R1

Condition (3): (P_LO-P_LI)≤ΔP_R2

3. heat pump according to claim 1 and 2, wherein,

4. according to the heat pump described in any one in claims 1 to 3, wherein,

5. a heat-pump-type hot-warer supplying machine, is characterized in that,

Described the 1st heat exchanger of the heat pump in claim 1 to 4 described in any one is handed over for making cold-producing medium and water carry out heatWater-the refrigerant heat exchanger of changing and water is heated.

6. a heat pump, is characterized in that, possesses:

All fuel tap, opens and closes described equal oily pipe arrangement; And

Control device, controls the on-off action of described equal fuel tap,

7. heat pump according to claim 6, wherein,

8. according to the heat pump described in claim 6 or 7, wherein,

9. according to the heat pump described in any one in claim 6 to 7, wherein,

10. a heat-pump-type hot-warer supplying machine, is characterized in that,

Described the 1st heat exchanger of the heat pump in claim 6 to 9 described in any one is handed over for making cold-producing medium and water carry out heatWater-the refrigerant heat exchanger of changing and water is heated.