JP4546188B2 - Waste heat utilization air conditioning system - Google Patents

Description

  The present invention relates to an exhaust heat utilization air conditioning system that uses, for example, exhaust heat of a distributed power source in a refrigeration cycle of an air conditioner.

In order to obtain a reduction in so-called primary fuels such as coal and oil, distributed power sources such as phosphoric acid fuel cells, gas engine generators, and micro gas turbine generators have been put on the market in the form of cogeneration.
In recent years, efforts have been made to develop a distributed power supply of a smaller scale (for example, a power generation capacity of 10 KW or less). In such small-scale distributed power sources, attention has been focused on solid polymer fuel cells that are small in scale, have good power generation efficiency, and are easy to handle.
However, since this type of distributed power source can reduce primary fuel only in the form of cogeneration, waste heat treatment during power generation in summer is important, regardless of winter. In general, waste heat treatment in summer is performed using an absorption refrigerator in the form of change to cold, but the operating efficiency is less than 0.1 because the waste heat temperature is as low as 80 ° C. Absent.

Recently, an adsorption refrigerator using an adsorbent has been developed. Even in this type of apparatus, the efficiency is only about 0.5. On the other hand, the amount of heat discharged from the above distributed power source is about 15 kW when considering the number of economically installed units, and even if an adsorption refrigeration machine is used, all of the cooling load can be achieved only with this exhaust heat. It is difficult to cover.
[Patent Document 1] describes an absorption refrigeration system using a turbo chiller, an absorption chiller, and a cold heat transfer circulation system that circulates a refrigerant in order to transfer cold heat between these chillers. A technology for supercooling liquid refrigerant by supplying cold heat generated by a machine to a turbo refrigerator via a cold heat transfer circulation system is disclosed. That is, the obtained cold energy is utilized for the increase in supercooling with respect to the refrigerant | coolant exit side refrigerant | coolant of an air conditioner.
JP 2003-207224 A

Of course, the same means can be used by using an adsorption refrigerator that has been attracting attention recently. However, actually, even if such an adsorption refrigerator is used, there are the following drawbacks.
(1) In order to output continuously, it becomes a batch system using a plurality of systems of the same type, which is expensive and increases the system volume.
(2) In the case of an adsorption refrigeration machine, two heat exchangers must be interposed between the generated cold heat and the refrigerant in order to transmit the cold heat obtained using water as a heat medium to the refrigerant in the refrigeration cycle of the air conditioner. The efficiency is reduced.
(3) The efficiency is greatly affected by the degree of vacuum in the system. Therefore, regular maintenance is required to maintain a high degree of vacuum, which is troublesome.

  The present invention has been made paying attention to the above circumstances, and the object of the present invention is to use exhaust heat of a heat source (distributed power source) as a negative pressure (vacuum side) without using a batch system. In addition, it is an object of the present invention to provide an exhaust heat utilization air conditioning system having a simple configuration and good thermal efficiency, without requiring a heat exchanger between the generated heat and the refrigerant of the air conditioner.

In order to satisfy the above-described object, in the exhaust heat utilization air conditioning system of the present invention, an exhaust heat treatment heat exchanger, an expander, an expander cycle condenser, and a pump are sequentially communicated with the exhaust heat guided from a heat source. Exhaust heat drive type Rankine cycle, a compressor that is mechanically connected to the expander in the exhaust heat drive type Rankine cycle and driven by the expander, and a heat generator that is arranged in parallel with the condenser for the expander cycle A refrigeration cycle for heat generation in which an outdoor heat exchanger and an expansion valve are sequentially communicated, and an air conditioner having a refrigeration cycle in which a compressor, a four-way switching valve, an outdoor heat exchanger and an indoor heat exchanger are sequentially communicated, and
During the cooling operation by the air conditioner, the refrigerant of the refrigeration cycle for heat generation is merged and mixed with the refrigerant guided to the refrigeration cycle of the air conditioner, and the cold heat is transferred to the refrigeration cycle of the air conditioner. Heat transfer means for transferring heat to the refrigeration cycle of the air conditioner by combining and mixing the mixed refrigerant of the Rankine cycle and the refrigeration cycle for heat generation into the refrigerant guided to the refrigeration cycle of the air conditioner during heating operation by It comprises.

  Advantageous Effects of Invention According to the present invention, there is an effect that the efficiency of an air conditioner is improved by using, for example, exhaust heat of a distributed power source that is a heat source.

Hereinafter, an exhaust heat utilization air conditioning system according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of an exhaust heat utilization air conditioning system according to a first embodiment of the present invention, in which FIG. 1 (A) shows a cooling operation and FIG. 1 (B) shows a heating operation.
The exhaust heat utilization air conditioning system includes an exhaust heat treatment heat exchanger 1, an expander 2, an expander cycle condenser 4, and a pump 6 that are sequentially communicated via a refrigerant pipe Pa to circulate the refrigerant. A drive type Rankine cycle R is provided.

The exhaust heat treatment heat exchanger 1 guides exhaust heat generated in, for example, a distributed power source N, which is a high heat source, through an exhaust heat pipe Pb, and exchanges heat with the refrigerant circulating in the Rankine cycle R. It is like that. The exhaust heat after the heat exchange by the exhaust heat treatment heat exchanger 1 is led to the distributed power source N again.
Further, the exhaust heat utilization air conditioning system includes a compressor 3 mechanically connected to the expander 2 constituting the Rankine cycle R, and heat generation combined with the expander cycle condenser 4 so that heat exchange is possible. The outdoor heat exchanger 5 and the expansion valve 7 are comprised. A heat transfer mechanism (heat transfer means) D, which will be described later, is interposed between the expansion valve 7 and the compressor 3, and a heat generating refrigeration cycle H for sequentially circulating the refrigerant through the refrigerant pipe Pc is provided. I have.

Further, the exhaust heat utilization air conditioning system includes a compressor 14, a four-way switching valve 13, an outdoor heat exchanger 11, and an indoor heat exchanger 12. The heat transfer mechanism D is interposed between the outdoor heat exchanger 11 and the indoor heat exchanger 12, and a refrigeration cycle S for sequentially circulating the refrigerant through the refrigerant pipe Pd is provided. And this refrigeration cycle S is provided in the air conditioner K shown with the broken line in a figure.
The heat transfer mechanism D includes a first expansion valve 9, an accumulator 8, and a second accumulator 8 provided in series with a refrigerant pipe Pd that connects between the outdoor heat exchanger 11 and the indoor heat exchanger 12 constituting the refrigeration cycle S. The expansion valve 10 is provided. Further, the first expansion valve 9 is configured with a parallel circuit a in which an on-off valve 16 is connected in parallel, and an on-off valve 15 is connected in parallel with a series circuit of the accumulator 8 and the second expansion valve 10. A parallel circuit b is configured.

In the heat generating refrigeration cycle H, the other end of the refrigerant pipe Pc, one end of which is connected to the compressor 3, is inserted into the accumulator 8, where the gas refrigerant separated from the gas and liquid is used. The refrigerant gas can be introduced and guided to the compressor 3, or refrigerant gas can be guided from the compressor 3 to the accumulator 8.
Further, in the refrigeration cycle H for heat generation, the other end of the refrigerant pipe Pc whose one end is connected to the expansion valve 7 is connected to the accumulator 8 and the parallel circuit a of the first expansion valve 9 and the on-off valve 16. The refrigerant is connected to the refrigerant pipe Pd therebetween, and the refrigerant can be led from the expansion valve 7 between the accumulator 8 and the parallel circuit a or in the reverse direction.

The heat transfer mechanism D configured in this way is shared by the refrigeration cycle H for heat generation and the refrigeration cycle S of the air conditioner K, and the refrigeration cycle H for heat generation constitutes a normal refrigeration cycle. In the refrigeration cycle S of the air conditioner K, a so-called heat pump refrigeration cycle is configured.
In such an exhaust heat utilization air conditioning system, the case where the air conditioner K performs a cooling operation will be described with reference to FIG.
Exhaust heat generated by the distributed power source N that is a heat source is guided to the heat treatment heat exchanger 1 for exhaust heat treatment constituting the Rankine cycle R through the exhaust heat pipe Pb, and exchanges heat with the refrigerant circulating in the refrigerant pipe Pa. To do. Exhaust heat whose temperature has dropped due to heat exchange is led out from the heat exchanger 1 for waste heat treatment and led to the distributed power source N. On the other hand, the refrigerant gas that has been subjected to heat exchange in the heat exchanger for exhaust heat treatment 1 and increased in temperature and pressure is guided to the expander 2 to generate power by expansion work.

By performing expansion work in the expander 2, the refrigerant gas is reduced in pressure, guided to the expander cycle condenser 4 and exchanged heat with the heat generating outdoor heat exchanger 5, and then guided to the pump 7 to increase the pressure. . Next, it is led again to the heat exchanger for exhaust heat treatment 1 to absorb the exhaust heat, and is further circulated through the above-mentioned path to repeat the same operation.
Further, when the expander 2 performs compression work, the compressor 3 of the refrigeration cycle H for heat generation that is mechanically connected to the expander 2 is driven. The high-temperature and high-pressure refrigerant gas discharged from the compressor 3 is guided to the heat generating outdoor heat exchanger 5 and exchanges heat with the expander cycle condenser 4 constituting the Rankine cycle R. Here, the condensed and liquefied refrigerant is guided to the expansion valve 7 and is introduced into the accumulator 8 constituting the heat transfer mechanism D in a state of intermediate temperature and intermediate pressure.

On the other hand, in the air conditioner K, the compressor 14 is driven, and the high-temperature and high-pressure refrigerant gas is led to the outdoor heat exchanger 11 via the four-way switching valve 13 to be condensed and liquefied. This liquid refrigerant is guided to the first expansion valve 9 constituting the heat transfer mechanism D and depressurized, and is introduced into the accumulator 8 in an intermediate temperature / intermediate pressure state.
That is, the medium-temperature / medium-pressure liquid refrigerant led from the heat generation refrigeration cycle H in the accumulator 8 of the heat transfer mechanism D and the medium-temperature / medium-pressure liquid refrigerant led from the refrigeration cycle S of the air conditioner K are mixed and Liquid separation. The gas refrigerant separated into gas and liquid in the accumulator 8 is sucked into the compressor 3 through the refrigerant pipe Pc of the heat generating refrigeration cycle H, and is compressed along with the expansion work of the Rankine cycle R. And it circulates through the path mentioned above again.
Further, the liquid refrigerant separated by the accumulator 8 is led out from the accumulator, led to the second expansion valve 10, and decompressed again. After that, it is led to the indoor heat exchanger 12 to evaporate, and the room is cooled.

Thus, in the exhaust heat utilization air conditioning system of the present invention, the cold heat generated in the heat generation refrigeration cycle H is refrigerated by the air conditioner K in the accumulator 8 constituting the heat transfer mechanism D without passing through the heat exchanger. Can be transmitted to cycle S. In addition, this system is not a batch system, and unlike the adsorption refrigeration machine, the system is filled with air-conditioning refrigerant, so there is no negative pressure and maintenance is not required. Has advantageous conditions such as compactness.
Next, the case where the air conditioner K performs the heating operation in the exhaust heat utilization air conditioning system will be described with reference to FIG.
At this time, the exhaust heat generated by the distributed power source N is guided to, for example, a hot water tank and used for hot water supply. That is, the exhaust heat of the distributed power source N is not led to the Rankine cycle R, and therefore the Rankine cycle is not driven.

Since the Rankine cycle R is not driven, expansion work is not generated in the expander 2, so the compressor 3 constituting the heat generating refrigeration cycle H is not driven, and no refrigerant is circulated in the refrigeration cycle H. That is, the medium-temperature and medium-pressure refrigerant is not guided to the heat transfer mechanism D as in the cooling operation.
While the four-way switching valve 13 of the refrigeration cycle S in the air conditioner K is switched, the on-off valve 15 of the heat transfer mechanism D is opened. The compressor 14 of the refrigeration cycle S is driven, and the high-temperature and high-pressure refrigerant gas compressed here is led to the indoor heat exchanger 12 to release the condensation heat, and the room is heated.
The liquid refrigerant derived from the indoor heat exchanger 12 is guided to the on-off valve 15 in the heat transfer mechanism D and bypasses the second expansion valve 10 and the accumulator 8. Further, depending on the presence or absence of an expansion valve mounted on the outdoor heat exchanger 11, the pressure is reduced or bypassed by the first expansion valve 9, and is led to the outdoor heat exchanger 11 to evaporate. Again, it is sucked into the compressor 14 through the four-way switching valve 13 and compressed, and circulates in the above-mentioned path.
That is, during the heating operation in the first embodiment, the exhaust heat of the distributed power supply N is not used, and therefore the air conditioner K is based on the pure heat pump refrigeration cycle S.

FIG. 2 is a configuration diagram of an exhaust heat utilization air conditioning system according to the second embodiment of the present invention, in which FIG. 2 (A) shows a cooling operation and FIG. 2 (B) shows a heating operation.
As will be described later, only parts different from those of the first embodiment described above with reference to FIG. 1 will be described, and the same parts will be denoted by the same reference numerals and new description will be omitted.
A four-way switching valve 20 is provided on the discharge side of the compressor 3 constituting the heat generating refrigeration cycle Ha. The remaining ports of the four-way switching valve are connected to the suction side of the compressor 3 and the refrigerant pipes Pc communicating with the heat generating outdoor heat exchanger 5 and the accumulator 8 of the heat transfer mechanism Da, respectively.

Further, between the refrigerant pipe Pc that communicates the discharge side of the compressor 3 and the four-way switching valve 20 and the refrigerant pipe Pa that communicates the expander 2 of Rankine cycle Ra and the condenser 4 for expander cycle, A bypass pipe Pe provided with a third on-off valve 21 is connected.
Auxiliary on-off valves 17 and 18 are provided in the front and rear refrigerant pipes Pa of the expander cycle condenser 4 in the Rankine cycle Ra. One end of a bypass pipe Pf is connected between one auxiliary on-off valve 18 and the pump 6, and is bypassed in the middle of the refrigerant pipe Pc that communicates the expansion valve 7 of the refrigeration cycle Ha for heat generation and the heat transfer mechanism Da. The other end of the pipe Pf is connected, and an auxiliary opening / closing valve 19 is provided in the middle of the bypass pipe Pf.

The heat transfer mechanism Da includes a first expansion valve 9, an accumulator 8, a parallel circuit c of the second expansion valve 10 and the on-off valve 16, an outdoor heat exchanger 11 and an indoor heat exchanger 12 in the refrigeration cycle S. Are provided in series.
As described above, the accumulator 8 is inserted with the refrigerant pipe Pc communicating with the four-way switching valve 20 in the heat generation refrigeration cycle Ha, and the refrigerant of the heat generation refrigeration cycle Ha to which the bypass pipe Pf is connected. Tube Pc is inserted. The refrigerant pipe Pc introduces the liquid refrigerant separated in the accumulator 8, or leads out the liquid refrigerant from the refrigerant pipe Pc.

Furthermore, the heat transfer mechanism Da has one end connected to the side of the accumulator 8 and the other end between the refrigerant pipe Pc and the refrigerant pipe Pd of the refrigeration cycle S and the first expansion valve 9. The bypass pipe Pg connected to is provided, and an open / close valve 15 is provided in the bypass pipe Pg.
At the time of the cooling operation shown in FIG. 2 (A), the on-off valve 21 provided in the bypass pipe Pe that connects the expander 2 discharge side of the Rankine cycle Ra and the compressor 3 discharge side of the heat generating refrigeration cycle Ha, and the bypass The on-off valve 19 provided in the middle part of the pipe Pf and the on-off valve 16 of the parallel circuit c in the heat transfer mechanism Da are closed. However, the auxiliary on-off valves 17 and 18 provided before and after the expander cycle condenser 4 are opened. Accordingly, the Rankine cycle R has exactly the same operation as that of the first embodiment, and a new description is omitted here.

In the heat generation refrigeration cycle Ha, the refrigerant gas discharged from the compressor 3 driven by the expander 2 of the Rankine cycle Ra is supplied to the heat generation heat exchanger 5 via the newly provided four-way switching valve 20. And exchanges heat with the refrigerant guided to the expander cycle condenser 4 of the Rankine cycle Ra.
Then, it is guided to the heat transfer mechanism Da through the expansion valve 7 and is separated into gas and liquid by the accumulator 8. Only the gas refrigerant is sucked into the compressor 3 from the accumulator 8 through the four-way switching valve 20. On the other hand, in the refrigeration cycle S of the air conditioner K, the compressor 14 is driven and performs the same operation as in the cooling operation in the first embodiment, and the same effect can be obtained. Therefore, further explanation of the operation in the refrigeration cycle S is omitted.

The heating operation shown in FIG. 2 (B) will be described below.
The auxiliary open / close valves 17 and 18 of the Rankine cycle Ra are closed, the open / close valve 21 and the open / close valve 19 communicating the Rankine cycle Ra and the heat generation refrigeration cycle Ha, and the open / close valve 16 of the parallel circuit c in the heat transfer mechanism Da. Is released. And the refrigerant | coolant guide | induced to the heat exchanger 1 for exhaust heat processing of the distributed power supply N and the heat processing 1 of Rankine cycle Ra heat-exchanges, and is guide | induced to the expander 2. FIG. Exhaust heat whose temperature has decreased due to heat exchange is led out from the heat exchanger 1 for waste heat treatment, and again led to the distributed power source N. On the other hand, the refrigerant gas increased in temperature and pressure in the heat exchanger 1 is led to the expander 2. It generates power from expansion work.
The refrigerant gas whose pressure has been reduced by performing expansion work in the expander 2 is all guided from the bypass pipe Pe to the heat generating refrigeration cycle Ha via the on-off valve 21 and does not return to the expander cycle condenser 4. The refrigerant gas led from the Rankine cycle Ra to the heat generating refrigeration cycle Ha is mixed with the high-temperature and high-pressure gas refrigerant discharged from the compressor 3 of the refrigeration cycle and led to the four-way switching valve 20. The four-way switching valve 20 is switched from that during the cooling operation, and the mixed refrigerant is guided to the accumulator 8 through the four-way switching valve to be gas-liquid separated.

On the other hand, in the refrigeration cycle S of the air conditioner K, the compressor 14 is driven, and the high-temperature and high-pressure refrigerant gas is led to the indoor heat exchanger 12 to condense, and the condensed heat is released to perform the indoor heating function. . The liquid refrigerant led out from the indoor heat exchanger 12 bypasses the second expansion valve 10 and is led from the on-off valve 16 to the accumulator 8 to be separated into gas and liquid.
As described above, the accumulator 8 is supplied with the refrigerant mixture with the Rankine cycle Ra from the refrigeration cycle Ha for heat generation, and performs heat exchange with the refrigeration cycle S in direct contact with the accumulator 8.
The liquid refrigerant in the refrigeration cycle S absorbs heat in the accumulator 8, rises in temperature, is led out from the accumulator, and the gas refrigerant separated in the accumulator 8 is led through the on-off valve 15 and mixed. Then, the pressure is reduced in the first expansion valve 9 , evaporated in the outdoor heat exchanger 11, and then sucked into the compressor 14 through the four-way switching valve 13.

On the other hand, a part of the liquid refrigerant led out from the accumulator 8 is led to the heat generation outdoor heat exchanger 5 through the expansion valve 7 of the heat generation refrigeration cycle Ha, and further from the four-way switching valve 20 to the expander 2. It is sucked into the driven compressor 3 and circulates in the above-mentioned path.
A part of the liquid refrigerant led out from the accumulator 8 is guided to the pump 6 of the Rankine cycle Ra via the auxiliary on-off valve 19. The refrigerant guided to the pump 6 is pressurized and flows into the exhaust heat treatment heat exchanger 1 and circulates in the above-described path.
In this way, during the heating operation, the mixed refrigerant of Rankine cycle Ra and heat generation refrigeration cycle Ha is guided to heat transfer mechanism Da and merged and mixed with the refrigerant guided to refrigeration cycle S of air conditioner K, thereby air conditioning. Heat is transferred to the refrigeration cycle S of the machine K.

FIG. 3 is a configuration diagram of an exhaust heat utilization air conditioning system according to a modification of the second embodiment of the present invention. FIG. 3 (A) shows a cooling operation, and FIG. 3 (B) shows a heating operation. Show.
As will be described later, only portions different from those of the second embodiment described above with reference to FIG. 2 will be described, and the same portions will be denoted by the same reference numerals and new description will be omitted.
The heat transfer mechanism Db is provided with an on-off valve 22 in the middle of the refrigerant pipe Pc that communicates the four-way switching valve 20 of the heat generating refrigeration cycle Ha and the accumulator 8 of the heat transfer mechanism Db. One end of the bypass pipe Ph is connected between the on-off valve 22 and the four-way switching valve 20. An on-off valve 23 is provided in the middle of the bypass pipe Ph, and the other end of the bypass pipe Ph bypasses the indoor heat exchanger 12 of the refrigeration cycle S and is connected to the discharge side of the compressor 14.

In the cooling operation shown in FIG. 3A, the on-off valve 22 is opened and the on-off valve 23 is closed. The auxiliary on-off valves 17 and 18 are opened. Accordingly, the Rankine cycle R, the heat generating refrigeration cycle Ha, and the refrigeration cycle S perform the same operations as those of the second embodiment, and the same effects can be obtained. Therefore, a new description is omitted here.
During the heating operation shown in FIG.
Contrary to the cooling operation, the on-off valve 22 is closed and the on-off valve 23 is opened. The auxiliary open / close valves 17 and 18 of the Rankine cycle Ra are closed, and the open / close valve 21 and the open / close valve 19 that connect the Rankine cycle Ra and the heat generating refrigeration cycle Ha are opened.

Exhaust heat of the distributed power source N and the refrigerant guided to the heat exchanger 1 for exhaust heat treatment of the Rankine cycle Ra are heat-exchanged and guided to the expander 2. Exhaust heat whose temperature has dropped due to heat exchange is exhausted from the heat exchanger 1 for exhaust heat treatment, and is led to the distributed power source N again. On the other hand, the refrigerant gas increased in temperature and pressure by the heat exchanger 1 is led to the expander 2. It generates power from expansion work.
The refrigerant gas whose pressure has been reduced by performing expansion work in the expander 2 is all guided from the bypass pipe Pe to the heat generating refrigeration cycle Ha via the on-off valve 21 and does not return to the expander cycle condenser 4. The refrigerant gas led from the Rankine cycle Ra to the heat generating refrigeration cycle Ha is mixed with the high-temperature and high-pressure gas refrigerant discharged from the compressor 3 of the refrigeration cycle and led to the four-way switching valve 20.

The mixed refrigerant is guided from the four-way switching valve 20 to the newly provided bypass pipe Ph, and is mixed and mixed with the high-temperature and high-pressure refrigerant gas discharged from the compressor 14 in the refrigeration cycle S through the on-off valve 23.
Accordingly, a sufficient amount of refrigerant and high-temperature and high-pressure refrigerant gas is led to the indoor heat exchanger 12 to condense, and the condensation heat is released to perform the indoor heating operation. The liquid refrigerant led out from the indoor heat exchanger 12 bypasses the second expansion valve 10 and is led from the on-off valve 16 to the accumulator 8 to be separated into gas and liquid.
The liquid refrigerant separated by the accumulator 8 is led to the first expansion valve 9 to be depressurized, and led to the outdoor heat exchanger 11 to evaporate. And it is sucked into the compressor 14 from the four-way switching valve 13 and circulates in the above-mentioned path.

On the other hand, a part of the liquid refrigerant led out from the accumulator 8 is led to the heat generating outdoor heat exchanger 5 through the expansion valve 7 of the heat generating refrigeration cycle Ha, and further driven by the expander from the four-way switching valve 20. Is sucked into the compressor 3 to be circulated through the above-mentioned path.
A part of the liquid refrigerant led out from the accumulator 8 is led from the bypass pipe Pf to the pump 6 of the Rankine cycle Ra via the auxiliary on-off valve 19. The refrigerant guided to the pump 6 is pressurized and flows into the exhaust heat treatment heat exchanger 1 and circulates in the above-described path.

In this way, during the heating operation, the mixed refrigerant of the Rankine cycle Ra and the heat generating refrigeration cycle Ha is merged and mixed with the refrigerant compressed and discharged by the compressor 14 in the refrigeration cycle S via the heat transfer mechanism Db. Heat is transferred to the refrigeration cycle S.
Therefore, the high-temperature exhaust heat in the distributed power source N can be used for the heating operation of the air conditioner K, and the heating efficiency can be improved. In addition, since heat is absorbed from the outside air in the heat generation refrigeration cycle Ha, more heat that has flowed into the exhaust heat treatment heat exchanger 1 can be used for air conditioning.

FIG. 4 is a configuration diagram of an exhaust heat utilization air conditioning system that basically employs a modification of the second embodiment described in FIG. 3 and adds a part thereof. FIG. During operation, FIG. 4B shows the heating operation.
As will be described later, only portions different from those described above with reference to FIG. 3 will be described, and the same portions will be denoted by the same reference numerals and new description will be omitted.
That is, here, a bypass pipe Pi that bypasses the expander is provided for the refrigerant pipe Pa connected to the expander 2 that constitutes the Rankine cycle Ra, and the bypass pipe includes an expansion valve 24.

FIG. 4A shows a state during cooling operation, and FIG. 4B shows a state during heating operation. Both are the same as the cooling operation state previously described in FIG. 3A and the heating operation state described in FIG.
5 (A) and 5 (B) show respective control flowcharts during the cooling / heating operation of FIGS. 4 (A) and 4 (B).
FIG. 5A is a control flowchart during cooling operation. When there is a cooling operation request in step S10 from the start, the cooling operation is started. Next, the process proceeds to step S11, where the temperature of the outdoor heat exchanger 11 constituting the refrigeration cycle S in the air conditioner K, that is, the condensation temperature is detected, and the detection signal is sent to the control unit (control means) 30.

Next, moving to step S12, the control unit 30 sends a control signal for changing the flow rate of the pump 6 constituting the Rankine cycle Ra according to the detected condensation temperature in the outdoor heat exchanger 11. Therefore, the inflow amount of exhaust heat obtained from the distributed power source N by the refrigerant circulating through the Rankine cycle Ra in the exhaust heat treatment heat exchanger 1 is variable.
That is, by controlling the flow rate of the pump 6 in the Rankine cycle Ra, the work of expansion in the expander 2 is influenced, and the amount of cold heat transferred to the refrigeration cycle S of the air conditioner K can be controlled via the heat transfer mechanism Db. And
FIG. 5B is a flowchart at the time of the heating operation, and when there is a heating operation request in step S1 from the start, the heating operation is started. Next, the process proceeds to step S2 and the heating operation is continued to reduce the load in the room, and the required operating frequency (that is, the required capacity) for the air conditioner K is stored in the control unit 30 in advance. In the state (Yes) which became smaller than c1, it moves to step S3 and stops the operation of the compressor 14 of the refrigeration cycle S.

In this state, exhaust heat is absorbed from the distributed power source N in the Rankine cycle Ra, and the expansion work is continued in the expander 2, and the compressor 3 of the refrigeration cycle Ha for heat generation is driven. Therefore, the high-temperature and high-pressure refrigerant is guided from the compressor 3 to the refrigeration cycle S through the four-way switching valve 20, the bypass pipe Ph and the opening / closing valve 23 and condensed in the indoor heat exchanger 12.
In this way, even when the required operating frequency for the air conditioner K is smaller than the first set value c1 stored in the control unit 30 in advance, the heating operation in the refrigeration cycle S is continued as much as necessary. Will do.
Then, the process proceeds to step S4, and the amount of heat absorbed from the outdoor heat exchanger 11 is controlled by varying the bypass flow rate of the expansion valve 24 provided to be bypassed with the expander 2 according to the required operating frequency.

When this state continues, the indoor load is further reduced, and the required operating frequency for the air conditioner K becomes smaller than the second set value c2 stored in the control unit 30 in advance. Then, it moves to step S5 and confirms that the required setting frequency with respect to the air conditioner K became smaller than the 2nd setting value c2 memorize | stored in the control part 30 previously (Yes).
Thereafter, the process proceeds to step S6, where the expansion valve 24 of the bypass pipe Pi is controlled to be fully opened to distribute the entire flow rate to the bypass pipe Pi, and the heat flow rate from the pump flow rate and exhaust heat is controlled according to the required frequency. Thereby, the operating cost in the air conditioner K can be saved.

When the required set frequency is larger than the preset set value c1 in step S1 (No), the process proceeds to step S7 and the refrigeration cycle S of the air conditioner K is operated.
In step S8, the operation frequency of the compressor 14 constituting the refrigeration cycle S of the air conditioner K is changed and controlled in accordance with the required frequency, the flow returns to the position before step S1, and the flow from step S1 is repeated again.
If the required set frequency is greater than the predetermined set value c2 in step S5, the flow returns to the position before step S4 and the flow from step S4 is repeated again.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram of the exhaust-heat utilization air conditioning system which shows 1st Embodiment in this invention, Comprising: (A) is at the time of cooling operation, (B) is a figure explaining the refrigerant | coolant circulation at the time of heating operation. It is a block diagram of the exhaust-heat utilization air-conditioning system which shows 2nd Embodiment in this invention, Comprising: (A) is at the time of cooling operation, (B) is a figure explaining the refrigerant | coolant circulation at the time of heating operation. It is a block diagram of the exhaust-heat utilization air-conditioning system which shows the modification of the embodiment, Comprising: (A) is a figure at the time of cooling operation, (B) is a figure explaining the refrigerant | coolant circulation at the time of heating operation. It is a block diagram of the exhaust-heat utilization air-conditioning system which shows the further different modification of the embodiment, Comprising: (A) is a figure at the time of cooling operation, (B) is a figure explaining the refrigerant | coolant circulation at the time of heating operation. It is a figure explaining the control method in the modification of the embodiment, (A) at the time of cooling operation, (B) is a control flowchart diagram at the time of heating operation.

Explanation of symbols

  N ... distributed power source (heat source), 1 ... heat exchanger for exhaust heat treatment, 2 ... expander, 4 ... condenser for expander cycle, 6 ... pump, R ... Rankine cycle, 3 ... compressor, 5 ... heat generation Outdoor heat exchanger, 7 ... expansion valve, H ... refrigeration cycle for heat generation, 14 ... compressor, 13 ... four-way switching valve, 11 ... outdoor heat exchanger, 12 ... indoor heat exchanger, S ... refrigeration cycle, K ... air conditioner, D ... heat transfer mechanism (heat transfer means), 30 ... control unit (control means).

Claims (2)

A heat exchanger for exhaust heat treatment for exchanging heat with exhaust heat derived from a heat source, an expander, a condenser for an expander cycle, and an exhaust heat driven Rankine cycle in which a pump is sequentially communicated;
A compressor that is mechanically connected to and driven by the expander in the exhaust heat driven Rankine cycle, an outdoor heat exchanger for heat generation and an expansion valve that are juxtaposed with the condenser for the expander cycle Refrigeration cycle for heat generation that is sequentially communicated,
An air conditioner having a refrigeration cycle in which a compressor, a four-way switching valve, an outdoor heat exchanger and an indoor heat exchanger are sequentially communicated;
During the cooling operation by the air conditioner, the refrigerant of the refrigeration cycle for heat generation is merged and mixed with the refrigerant guided to the refrigeration cycle of the air conditioner, and heat is transferred to the refrigeration cycle of the air conditioner,
During the heating operation by the air conditioner, the mixed refrigerant of the Rankine cycle and the heat generating refrigeration cycle is mixed and mixed with the refrigerant guided to the refrigeration cycle of the air conditioner, and heat is heated to the refrigeration cycle of the air conditioner. An exhaust heat utilization air conditioning system comprising: a heat transfer means for transmitting heat. During heating operation by the air conditioner, the power generated by the expander of the Rankine cycle is determined according to the required capacity for the air conditioner, and during cooling operation, according to the condensation temperature of the outdoor heat exchanger of the air conditioner. The exhaust heat utilization air conditioning system according to any one of claims 1 and 2, further comprising control means for controlling.

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