JP3859568B2 - Hybrid air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hybrid air conditioner that combines an absorption refrigerator and a compression heat pump.
[0002]
[Prior art]
In an absorption refrigerator using a lithium salt solution (absorption solution) such as lithium bromide, the absorption liquid is heated by a regenerator to be separated into a solvent vapor and a concentrated absorption solution and supplied to a refrigeration unit. The refrigeration unit consists of a solvent condenser that liquefies the solvent vapor, a solvent evaporator that cools the working fluid while evaporating the liquefied solvent, and absorption water that is generated while absorbing the evaporated solvent in the concentrated absorbent solution is absorbed by the cooling water. And an absorber that cools the absorbing liquid and keeps the evaporation of the liquefied solvent in the solvent evaporator.
[0003]
When cooling operation is performed using an absorption refrigerator, a cooling mechanism is attached to the solvent condenser and the absorber in order to discharge the condensation heat and absorption heat of the solvent vapor to the atmosphere. Air conditioning fluid is circulated with the air conditioning heat exchanger. The cooling mechanism is usually a water-cooled cooling tower (cooling tower) that removes heat by circulating cooling water.
[0004]
The refrigerating capacity of the absorption refrigerator during cooling operation is proportional to the evaporation amount of the liquefied solvent in the solvent evaporator, and the evaporation amount depends on the absorption amount in the absorber. In order to improve the refrigerating capacity or downsize the refrigeration unit, it is important to improve the absorption efficiency of the solvent vapor in the absorber. The improvement in absorption efficiency can be achieved by increasing the contact area between the absorption liquid and the solvent vapor in the absorber, and by quickly transferring the generated absorption heat to the cooling water (for example, patent document). 1).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-61986
[Problems to be solved by the invention]
Water-cooled cooling towers require maintenance and management (maintenance) for the removal of water and solutes dissolved in water, which is a burden on small air conditioners such as home use and causes practicality to decline. Yes. If an air-cooled cooling tower is used, it is easy to maintain and manage, but the water-cooled cooling tower can cool the absorption solution to around 40 ° C. with cooling water (air conditioning fluid can be lowered to 5-6 ° C.), Since the air-cooled cooling tower can only cool the absorbing solution to about 50 ° C. by air (air-conditioned fluid can only be lowered to about 10 ° C.), the solution concentration must be reduced to lower the air-conditioned fluid to 5-6 ° C. by air-cooling. It will be necessary to raise it about 5%. When the concentration of the solution is increased by about 5%, problems such as crystallization of the solution, temperature increase of the regenerator, material corrosion, and generation of hydrogen occur.
[0007]
An object of the present invention is to provide a hybrid air conditioner that can increase the air conditioning capability without increasing the solution concentration and can be easily maintained and managed.
[0008]
[Means for Solving the Problems]
Hybrid air conditioner of the present invention, regenerator absorbent solution by heating is separated into a solvent and concentrated absorbent solution, the solvent condenser for condensing the separated solvent vapors, solvent evaporator for evaporating the solvent, the evaporated solvent An absorber to be absorbed into the concentrated absorbent solution, an absorption refrigerator having a pump for recirculating the diluted absorbent solution by absorbing the solvent to the regenerator, an air conditioner having an air conditioning heat exchanger through which the air conditioning fluid circulates, A hybrid air conditioner comprising a refrigerant compressor, a refrigerant heat exchanger, and a compression refrigerator having a refrigerant expansion valve, and during cooling operation, a circuit for circulating the refrigerant between the compressor refrigerator and the absorber; By switching to a circuit that circulates air-conditioned fluid between the solvent evaporator and the air-conditioning heat exchanger, the heat generated when the evaporated solvent is absorbed by the concentrated absorbent solution is exchanged for refrigerant heat in the compression refrigerator. Atmosphere At the time of heating operation, the atmospheric heat is switched by switching to a circuit for circulating the refrigerant between the compression refrigerator and the solvent evaporator and a circuit for circulating the air-conditioning fluid between the absorber and the air-conditioning heat exchanger. Is absorbed by a refrigerant heat exchanger of a compression refrigerator and discharged by a solvent evaporator.
Furthermore, this hybrid air conditioner guides and condenses the solvent vapor in the solvent condenser to an external heat exchanger that can be forcibly cooled by a blower attached to the refrigerant heat exchanger, and releases the condensation heat from the external heat exchanger to the atmosphere. It can be done.
[0009]
【The invention's effect】
In the present invention, during the cooling operation, the refrigerant is circulated through the absorber by the compression refrigerator and the absorbed heat is released to the atmosphere. For this reason, the maintenance is easy, the cooling capacity can be increased, and the problem of the absorption refrigerator can be avoided. In addition, the compression refrigeration machine is compact and produced in large quantities, so it is low-cost, enabling effective use of the installation space and cost reduction, and cooling and heating operations can be performed with a single facility. Become.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described with the embodiments shown in the drawings. FIG. 1 shows the flow of the working fluid during the hybrid air conditioner 1 and the cooling operation according to the present embodiment, and FIG. 2 shows the flow of the working fluid during the heating operation and the hybrid air conditioner 1 according to the present embodiment. The hybrid air conditioner 1 includes an absorption refrigerator 2 using a lithium salt solution (hereinafter referred to as an absorption solution) such as an aqueous lithium bromide solution and a compressive fluid (hereinafter referred to as a refrigerant) such as freon and carbon dioxide. Is a combination of a compression refrigeration machine 3 using a working fluid and an air conditioner 4 using a fluid of the same type as the refrigerant as an air conditioning fluid.
[0011]
The absorption refrigerator 2 includes a high-temperature regenerator 21, a separator 22 disposed above the high-temperature regenerator 21, and a negative pressure tank 5, each of which is connected by an absorption solution or solvent flow path. The high-temperature regenerator 21 is a solution tank 25 in which the fresh liquid recirculates from the bottom of the negative pressure tank 5 via a fresh liquid flow path 24 of a low concentration absorbing solution (referred to as a fresh liquid) provided with a solution pump 23. And a heating source (burner) B for heating the solution tank 25. The fresh liquid heated and boiled by the high-temperature regenerator 21 is separated by the separator 22 into water (solvent) vapor and a concentrated medium concentration absorbing solution (referred to as medium liquid).
[0012]
The water vapor and the high-temperature medium liquid are supplied separately through a solvent flow path 26 and a medium-liquid flow path 27 to a low-temperature regenerator 51 installed in the upper part of the negative pressure tank 5. At this time, the high-temperature intermediate liquid flowing through the intermediate liquid flow path 27 and the fresh liquid returning to the solution tank 25 via the fresh liquid flow path 24 are heat-exchanged by the high-temperature heat exchanger 11 in order to improve thermal efficiency. The A regenerative heat exchanger 52 is provided in the low-temperature regenerator 51, and heat exchange between the water vapor in the solvent flow path 26 and the intermediate liquid is performed, and the water vapor condenses into water. The middle liquid re-boils, and water vapor and a high concentration absorbing solution (referred to as a concentrated liquid) are produced.
[0013]
The water vapor generated by the low temperature regenerator 51 is guided to the solvent condenser 6 installed in the upper part of the negative pressure tank 5.
During the cooling operation, as shown in FIG. 1, the water vapor in the solvent condenser 6 is transferred to the external heat exchanger 63 that is forcedly cooled by the blower 33 of the compression refrigeration machine 3, which will be described later, through the water vapor flow path 60 having the valve 66. It is guided, condensed and refluxed to the solvent container 62. The condensation heat is released from the external heat exchanger 63 to the atmosphere.
During the heating operation, as shown in FIG. 2, the water vapor in the solvent condenser 6 flows into the internal heat exchanger 61 provided in the solvent condenser 6, and is condensed on the surface of the internal heat exchanger 61. Accumulate at 62. Condensation heat is absorbed by the air-conditioning fluid flowing in the internal heat exchanger 61.
[0014]
Under the negative pressure tank 5, an absorber 7 having an absorption heat exchanger 71 and a solvent evaporator 8 having an evaporation heat exchanger 81 are provided. In the absorption heat exchanger 71, the concentrated liquid supplied through the concentrated liquid channel 64 is sprayed from above. At this time, the concentrated liquid is heat-exchanged in the low-temperature heat exchanger 12 with the fresh liquid flowing back to the solution tank 25 via the fresh liquid flow path 24. In the evaporation heat exchanger 81, water accumulated in the solvent container 62 is sprayed from above through the solvent flow path 65.
[0015]
The water sprayed on the evaporating heat exchanger 81 evaporates on the surface of the evaporating heat exchanger 81, and cools the air-conditioning fluid flowing in the evaporating heat exchanger 81 with evaporating heat. The evaporated water is absorbed by the concentrated liquid on the surface of the absorption heat exchanger 71, and the absorption heat generated at this time is absorbed by the working fluid flowing in the absorption heat exchanger 71.
[0016]
The compression refrigerator 3 includes a refrigerant compressor 31, a refrigerant heat exchanger 32 and an expansion valve 34 connected to the refrigerant compressor 31 through a refrigerant flow path 30. A fan 33 is attached to the refrigerant heat exchanger 32.
[0017]
During the cooling operation, the refrigerant is compressed by the refrigerant compressor 31 and becomes a high temperature, and is cooled by the blower 33 in the refrigerant heat exchanger 32 to release condensed heat to the atmosphere. The condensed refrigerant expands at the expansion valve 34 and becomes a low temperature, and is supplied to the absorption heat exchanger 71. The low-temperature refrigerant absorbs the absorption heat generated on the surface of the absorption heat exchanger 71 to cool the absorption liquid. That is, the compression refrigerator 3 has an action of quickly releasing the heat generated by the absorption heat exchanger 71 to the atmosphere, thereby increasing the cooling capacity of the hybrid air conditioner 1.
[0018]
During the heating operation, the refrigerant is expanded by the expansion valve 34, supplied with heat by the blower 33 in the refrigerant heat exchanger 32 and evaporated, and absorbs atmospheric heat as evaporation heat. The evaporated refrigerant is compressed by the refrigerant compressor 31 and becomes high temperature, and is supplied to the evaporation heat exchanger 81. The refrigerant condenses in the evaporation heat exchanger 81 and supplies the condensation heat to the solvent vapor generated on the surface of the evaporation heat exchanger 81 as evaporation heat. In other words, the compression refrigerator 3 has an action of quickly supplying the atmospheric heat obtained by the refrigerant heat exchanger 32 to the solvent vapor generated by the evaporating heat exchanger 81, and increases the heating capacity of the hybrid air conditioner 1. I am letting.
[0019]
The air conditioner 4 includes a pump 41 and a load 42 such as an indoor heat exchanger that is connected to the pump 41 by an air conditioning channel 40.
[0020]
The refrigerant flow path 30, the air conditioning flow path 40, the internal heat exchanger 61, the absorption heat exchanger 71, and the evaporative heat exchanger 81 have two four-way valves 91, in order to enable switching between the cooling operation and the heating operation. 92 and one three-way valve 93. In addition, since it is necessary to reverse the refrigerant flow between the cooling operation and the heating operation, a four-way valve 94 is provided between the refrigerant compressor 31 and the refrigerant heat exchanger 32 in the refrigerant flow path 30.
[0021]
The four-way valve 91 has an absorption heat exchanger 71 as a first port, a load 42 in the air conditioning channel 40 as a second port, an expansion valve 34 in the refrigerant channel 30 as a third port, and an evaporating heat exchanger 81 as a fourth port. It is connected. The four-way valve 92 has a first port as the evaporative heat exchanger 81, a second port as the pump 41 in the air conditioning channel 40, a third port as the four-way valve 94 in the refrigerant channel 30, a fourth port as the internal heat exchanger 61, and A three-way valve 93 is connected. The four-way valve 94 has a first port connected to the inlet side of the refrigerant compressor 31, a second port connected to the four-way valve 92, a third port connected to the refrigerant heat exchanger 32, and a fourth port connected to the outlet side of the refrigerant compressor 31. Yes.
[0022]
During the cooling operation, the refrigerant absorbs the heat generated by the absorption heat exchanger 71 and is released to the atmosphere by the compression refrigerator 3. Therefore, the four-way valve 91 has a flow path from the third port to the first port, the four-way valve 92 has a flow path from the fourth port to the third port, and the three-way valve 93 has a flow path so that the refrigerant flows from the absorption heat exchanger 71 to the four-way valve 92. Switch. In the four-way valve 94, in order to release the refrigerant condensation heat into the atmosphere, the refrigerant enters the refrigerant compressor 31 from the second port via the first port, and is sent from the fourth port to the refrigerant heat exchanger 32 via the third port. Switch the flow path to.
[0023]
The air-conditioning fluid absorbs room heat by the load 42 and releases it as evaporation heat by the evaporation heat exchanger 81. Therefore, the flow path is switched so that the conditioned fluid flows from the second port to the fourth port in the four-way valve 91 and from the first port to the second port in the four-way valve 92.
[0024]
During the heating operation, the refrigerant absorbs atmospheric heat in the compression refrigerator 3 and releases it as evaporation heat in the evaporation heat exchanger 81. Therefore, the flow path is switched so that the refrigerant flows from the fourth port to the third port in the four-way valve 91 and from the third port to the first port in the four-way valve 92. In the four-way valve 94, atmospheric heat is absorbed as refrigerant evaporating heat, so that the refrigerant enters the refrigerant compressor 31 from the third port through the first port, and the evaporating heat exchanger 81 and the expansion valve 34 from the fourth port through the second port. Then, the flow path is switched so as to be sent in the order of the refrigerant heat exchanger 32.
[0025]
The air-conditioning fluid absorbs absorbed heat with the absorption heat exchanger 71, absorbs heat of condensation with the internal heat exchanger 61, and discharges it into the room with the load 42. Therefore, the air-conditioning fluid flows from the second port to the first port in the four-way valve 91, from the fourth port to the second port in the four-way valve 92, and from the absorption heat exchanger 71 to the internal heat exchanger 61 in the three-way valve 93. Switch the flow path.
[0026]
The hybrid air conditioner 1 is easy to maintain and assists cooling or heating operation by the mass-produced compression refrigerator 3. For this reason, it is highly practical, and even if the outside air temperature is high, heat dissipation from the refrigerant to the atmosphere will not be insufficient, and conversely, even if it is low, the absorption of atmospheric heat to the refrigerant will not be insufficient. .
Further, it is possible to switch between the cooling operation and the heating operation only by switching the flow paths of the three four-way valves 91, 92, 94 and the one three-way valve 93.
[0027]
[Modification]
In this embodiment, the water vapor channel 60 is used to condense the water vapor in the solvent condenser 6 during the cooling operation, but the refrigerant after passing through the absorption heat exchanger 71 is the internal heat of the solvent condenser 6. A circuit flowing in the exchanger 61 may be used so that the heat of condensation of the water vapor is absorbed by the refrigerant flowing in the internal heat exchanger 61.
[Brief description of the drawings]
FIG. 1 shows a schematic diagram of a hybrid air conditioner of the present embodiment and the flow of a working fluid during cooling operation.
FIG. 2 is a schematic diagram of the hybrid air conditioner of the present embodiment and shows the flow of working fluid during heating operation.
[Explanation of symbols]
21 High temperature regenerator 31 Refrigerant compressor 34 Expansion valve 42 Load 5 Negative pressure tank 51 Low temperature regenerator 6 Solvent condenser 7 Absorber 8 Solvent evaporator

Claims (2)

A regenerator that heats the absorption solution to separate it into a solvent and a concentrated absorption solution, a solvent condenser that condenses the separated solvent vapor, a solvent evaporator that evaporates the solvent, and absorbs the evaporated solvent into the concentrated absorption solution An absorber, an absorption refrigerator having a pump that absorbs the solvent and dilutes the diluted absorption solution to the regenerator;
An air conditioner equipped with an air conditioning heat exchanger through which air conditioning fluid circulates;
A hybrid air conditioner comprising a refrigerant compressor, a refrigerant heat exchanger, and a compression type refrigerator having a refrigerant expansion valve,
During cooling operation, by switching to a circuit for circulating refrigerant between the compression refrigerator and the absorber, and a circuit for circulating the air-conditioned fluid between the solvent evaporator and the air-conditioning heat exchanger, Absorption heat generated when the evaporated solvent is absorbed by the concentrated absorbent solution is released to the atmosphere by the refrigerant heat exchanger of the compression refrigerator, and during the heating operation, the compression refrigerator and the solvent evaporate. Switching to a circuit that circulates the refrigerant between the absorber and a circuit that circulates the air-conditioning fluid between the absorber and the air-conditioning heat exchanger, thereby converting atmospheric heat into the refrigerant heat of the compression refrigerator. Absorbed by the exchanger and discharged by the solvent evaporator ,
Solvent vapor in the solvent condenser can be led to an external heat exchanger that can be forcibly cooled by a blower attached to the refrigerant heat exchanger and condensed, and condensation heat can be released from the external heat exchanger to the atmosphere. A hybrid air conditioner characterized by 2. The hybrid air conditioner according to claim 1, wherein the regenerator is a high-temperature regenerator that heats a low-concentration lithium salt solution with a heating source to evaporate the solvent and generates a medium-concentration lithium salt solution; A hybrid air conditioner comprising a low-temperature regenerator that reheats the medium concentration lithium salt solution with condensation heat to evaporate the solvent and generate a high concentration lithium salt solution.

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