JP2836154B2 - Waste heat recovery heat pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to an exhaust heat recovery type heat pump, for example, used in an air conditioner constituted by a gas engine driven heat pump device. Can be

(Prior art) An air conditioner (hereinafter abbreviated as GHP) consisting of a gas engine driven heat pump device.
It is known to use the exhaust heat of a gas engine to improve the heating capacity in winter.

For example, in the "Aisin Seiki Co., Ltd. 10 hp gas heat pump air conditioner service manual" issued in July 1989, the cooling water circuit of the gas engine installed in the GHP outdoor unit was replaced by the GHP indoor unit. To the side,
The heat of the high-temperature cooling water is radiated by an indoor heat exchanger separate from the heat pump circuit, and used as an auxiliary heating source for indoor heating.

(Problems to be Solved by the Invention) However, in the GHP using the above-described method, the piping between the outdoor unit and the indoor unit is two pipes for reciprocating heat pump circuit and two pipes for reciprocating cooling water circuit. Therefore, a total of four pipelines are required, and the installation work of the GHP is troublesome, and the installation work cost is high.

In view of the above, it is a technical object of the present invention to improve the heating performance in winter without extending the cooling water circuit to the indoor unit side of the GHP.

[Configuration of the invention]

(Means for Solving the Problems) The technical means of the present invention taken to solve the above-mentioned technical problem of the present invention is connected to a combustion engine, a compressor driven by the combustion engine, and the compressor. A first heat exchanger, a second heat exchanger connected to an expansion valve connected to the first heat exchanger, a refrigerant circuit including a compressor connected to the second heat exchanger, And a cooling circuit including a third heat exchanger and a fourth heat exchanger that are connected in parallel with the combustion engine by circulating air through the combustion engine. The third heat exchanger includes a first working chamber and a second working chamber. A first working fluid circulating in the refrigerant circuit is introduced into the first working chamber, a second working fluid circulating in the cooling circuit is introduced into the second working chamber, and suction of the first working chamber is performed. Side is connected between the first heat exchanger and the expansion valve via a first check valve, The discharge side of the working chamber is connected to the discharge side of the compressor via a second check valve, and is connected to the suction side of the compressor via a control valve which is controlled to be opened and closed by control means, and is introduced into the first working chamber. The control means opens the control valve when the first working fluid is evaporated.

(Operation) According to the technical means of the present invention described above, heat exchange can be performed with high efficiency between the cooling circuit and the heat pump circuit, and the cooling water circuit extends to the indoor unit side of the GHP. It is possible to improve the heating capacity in winter without the need.

(Example) Hereinafter, an example that embodies the technical means of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an exhaust heat recovery type heat pump 10 according to an embodiment of the present invention. FIG. 2 is an explanatory view of the hot water-refrigerant heat exchanger 14.

A passage cavity is formed in a cylinder block (not shown) of the gas engine 11 to radiate heat generated by combustion of the gas engine 11 to cooling water. The cooling circuit 12 of the gas engine 11 connects a radiator 13 and a hot water-refrigerant heat exchanger 14 in parallel. In the middle of the cooling circuit 12, a pump 15 and a switching valve 16 are provided.

The compressor 17 is driven by the gas engine 11, and its discharge side 17 a is connected to one end of the indoor heat exchanger 19 via a four-way valve 18. The other end of the indoor heat exchanger 19 is
It is connected to a receiver 21 via a manifold valve 20 composed of two check valves 20a, 20b, 20c, 20d. Next, the outflow side 21a of the receiver 21 is provided with a filter dryer 22,
It is connected to an outdoor heat exchanger 24 via an expansion valve 23 and a manifold valve 20. Further, one end of the outdoor heat exchanger 24 is connected to the inflow side 25b of the accumulator 25 through the four-way valve 18.
The outlet side 25a of the accumulator 25 is connected to the suction side 17b of the compressor 17 to constitute a heat pump 26 in which the refrigerant circulates.

The hot water-refrigerant heat exchanger 14 includes a refrigerant working chamber 14a and a hot water working chamber 14b. Here, the cooling water of the gas engine 11 circulating in the cooling circuit 12 is circulated in the hot water working chamber 14b.

On the other hand, the inlet 27 of the refrigerant working chamber 14a is connected to the outlet 21a of the receiver 21 via a check valve 28. The outlet 29 of the refrigerant working chamber 14a is divided into two parts, one of which is connected to the discharge side 17a of the compressor 17 via a check valve 30, and the other of which is a control valve which is opened and closed by a control means 32. 31
Is connected to the inflow side 25b of the accumulator 25.

Further, output signals output from the three temperature sensors 35, 36, 37 are input to the control means 32. That is, the refrigerant working chamber 14
A temperature sensor 35 disposed at a branch point 38 at the end of the outlet 29 of a
And a temperature sensor 36 provided at one end of a throttle portion 34 formed in the middle of a pipe 33 connecting the outlet 29 and the control valve 31 to the liquid refrigerant discharge side (at the time of heating) of the indoor heat exchanger 19. The temperature sensor 37 is provided.

The operation of the exhaust heat recovery type heat pump 10 having the above configuration will be described below.

The exhaust heat recovery type heat pump 10 is used in an air conditioner as described above, and its operation will be described based on the air conditioner.

FIG. 1 shows a heating state of the air conditioner. The high temperature discharged from the discharge side 17a of the compressor 17 is shown in FIG.
The high-pressure gaseous refrigerant is supplied to the indoor heat exchanger 19 through the four-way valve 18.
To heat the refrigerant by radiating the heat in the refrigerant to the room.

Thereafter, the refrigerant radiates heat to become a high-temperature and high-pressure liquid refrigerant, passes through a check valve 20c in the manifold valve 20, and flows into the receiver 21. The high-temperature and high-pressure liquid refrigerant flowing out of the receiver 21 is divided into two directions.

One of the refrigerants passes through an expansion valve 23 via a filter dryer 22, and becomes a low-temperature and low-pressure gas-liquid refrigerant at the expansion valve 23. This refrigerant is supplied to the check valve 20a in the manifold valve 20.
Although it should be able to flow to any of 20b and 20d, the outlet side of the check valves 20a and 20d is in a high temperature and high pressure state, so that the refrigerant in a low temperature and low pressure state cannot flow out. Accordingly, the refrigerant that has passed through the expansion valve 23 flows out to the outdoor heat exchanger 24.

In the outdoor heat exchanger 24, the low-temperature and low-pressure gas-liquid refrigerant absorbs the heat of the outside air and becomes a low-temperature and low-pressure gaseous refrigerant. Thereafter, the refrigerant flows through the check valve 18 to the accumulator 25.
And then circulates to the compressor 17.

Now, the other refrigerant diverted from the receiver 21 is
Through the hot water-refrigerant heat exchanger 14 to the refrigerant working chamber 14a. Here, the control valve 31 is controlled to be opened and closed by the control means 32, and the control means 32 opens the control valve 31 when the refrigerant in the refrigerant working chamber 14a is in a heated state (a state in which all of the refrigerant becomes a gas phase by evaporation). Accordingly, the liquid refrigerant is rapidly stored in the refrigerant working chamber 14a, and when the refrigerant working chamber 14a is filled with the liquid refrigerant, the control means 32 senses this and closes the control valve 31. At this time, since hot water in the cooling circuit 12 is circulating in the hot water working chamber 14b of the hot water-refrigerant heat exchanger 14, heat exchange proceeds between the hot water and the liquid refrigerant, and the liquid refrigerant gradually becomes gaseous. It will become. During this gasification, the inside of the refrigerant working chamber 14a becomes higher in pressure than the outlet side of the check valve 30, and the gaseous refrigerant is discharged from the check valve 30 to the discharge side 17a of the compressor 17, and the indoor heat exchanger 19 Radiates heat indoors.

Therefore, in the indoor heat exchanger 19, the refrigerant is
Since not only the heat obtained in step (1) but also the heat obtained in the hot water-refrigerant heat exchanger 14 is radiated, the heating capacity can be improved.

Thereafter, when all the refrigerant in the refrigerant working chamber 14a is gasified and becomes overheated, the control valve 32 is opened by the control means 32, and substantially the entire gaseous refrigerant is discharged to the inflow side 25b of the accumulator 25. Naturally, this refrigerant is also used in the indoor heat exchanger 19
Because it radiates heat, it is useful for improving the heating capacity.

At this time, the refrigerant in the refrigerant working chamber 14a flows out of the control valve 31 and at the same time, the pressure in the refrigerant working chamber 14a decreases, so that the liquid flows into the refrigerant working chamber 14a from the receiver 21 through the check valve 28. When the refrigerant is rapidly stored and the refrigerant working chamber 14a is filled with the liquid refrigerant, the control means 32 senses this and closes the control valve 31, so that the above-described heat exchange cycle is repeated.

The switching valve 16 is controlled to be switched by control means (not shown). Usually, the cooling circuit 12 is formed so as to connect the inside of the gas engine 11 and the hot water-refrigerant heat exchanger 14, and the hot water-refrigerant heat exchange is performed. Since the heat exchange capacity of the vessel 14 is limited,
When the cooling water in the cooling circuit 12 is not sufficiently cooled by the hot water-refrigerant heat exchanger 14 and hinders cooling of the gas engine 11, the cooling circuit 12 connects the inside of the gas engine 11 and the radiator 13. To form

Here, the control means 32 determines how the refrigerant working chamber 14
A method for determining whether the refrigerant a is overheated and whether the refrigerant working chamber 14a is filled with the liquid refrigerant will be described.

First, in the former detection method, the control valve 31 is closed until the refrigerant in the refrigerant working chamber 14a is filled with the liquid and becomes overheated, and the heat exchange proceeds in the hot water-refrigerant heat exchanger 14. . At this time, the control means 32 monitors the output signals of the temperature sensors 35 and 37, and if the temperature detected by the temperature sensor 35 becomes higher than the temperature output from the temperature sensor 37 even in consideration of the supercooling temperature, Naturally, it can be determined that the refrigerant in the refrigerant working chamber 14a is in an overheated state. Therefore, at this time, the control means 32 opens the control valve 31.

Next, the latter detection method, at the same time as the refrigerant in the overheated state in the refrigerant working chamber 14a escapes from the opened control valve 31,
After the liquid refrigerant accumulates in the refrigerant working chamber 14a due to the negative pressure and is completely filled, the refrigerant overflowing into the pipeline 33 flows out. At this time, the temperature of the liquid refrigerant detected by the temperature sensor 36 is lower than the temperature detected by the temperature sensor 35 because the liquid refrigerant tries to gasify in the throttle portion 34 and removes external heat by the action of the throttle portion 34. Therefore, this is
The control valve 31 is closed when the control valve 32 detects it.

On the other hand, although the cooling state of the air conditioner is not shown, the configuration of the heat recovery heat pump 10 is as follows. That is, the connection state of the four-way valve 18 is switched, the discharge side 17a of the compressor 17 and the outdoor heat exchanger 24 are connected, and the indoor heat exchanger 19 and the inflow side of the accumulator 25 are connected.
25b is connected.

In the cooling state, the control valve 31 is always closed, and the refrigerant in the refrigerant working chamber 14a of the hot water-refrigerant heat exchanger 14 is completely gasified and the control valve 31 does not open even in the overheated state. No liquid refrigerant newly flows from the receiver 21 into the chamber 14a. Therefore, the hot water-refrigerant heat exchanger 14 does not operate in the cooling state.

FIG. 3 shows another configuration of the cooling circuit. A thermostat valve 50 is provided in the cooling circuit 12 instead of the switching valve 16 of FIG. 1, and flows to the radiator 13 as the temperature of the cooling water rises. The amount of cooling water is increased.

FIG. 4 shows another configuration of the cooling circuit.
Thermostat valve at the outlet of engine 11 of cooling water circuit 60
A bypass passage 63 provided with a throttle valve 64 in the middle
Extends to the upstream side of the water pump 65.

Further, the exhaust gas heat exchanger 61 is installed in the exhaust pipe of the engine 11.
And a cooling water circuit connected to the engine 11
It is connected in parallel with the engine 11 in the middle of 60.

The hot water / refrigerant heat exchanger 14 provided in the cooling water circuit 60 has a radiator 13 and a bypass passage 66 connected in parallel and connected in series via a thermostat valve 67.

〔The invention's effect〕

As described above, in the present invention, the cooling circuit and the refrigerant circuit are respectively connected to the third heat exchanger, and the second working fluid circulating in the cooling circuit and the first working fluid circulating in the refrigerant circuit are connected to each other. Since heat is exchanged between the GHPs, the heating capacity in winter can be improved without extending the cooling circuit to the indoor unit side of the GHP.

The discharge side of the first working chamber is connected to the discharge side of the compressor via a second check valve, and is connected to the suction side of the compressor via a control valve that is controlled to be opened and closed by control means. Therefore, when the control valve is opened, the first working fluid in the first working chamber is discharged to the suction side of the compressor via the control valve. For this reason, the pressure in the first working chamber decreases, and the liquid high-temperature, high-pressure first working fluid is introduced into the first working chamber. As described above, the first working fluid can be introduced into the third heat exchanger by a simple operation of opening the control valve without requiring a pumping means such as a pump.
Further, since the opening and closing control of the control valve is performed based on the state of the first working fluid in the first working chamber, the control valve is opened when most of the first working fluid in the first working chamber is in a gaseous state. In this case, the first working fluid, which is mostly gasified by the heat exchange, is discharged from the third heat exchanger, and the liquid first working fluid is introduced into the third heat exchanger to perform heat exchange. In this way, heat exchange between the first working fluid and the second working fluid can be performed with high efficiency.

Further, the control valve is opened when all of the first working fluid introduced into the third heat exchanger evaporates, so that the refrigerant which has evaporated and becomes high temperature and high pressure is not overheated. To prevent problems caused by

[Brief description of the drawings]

FIG. 1 shows an exhaust heat recovery type heat pump 10 according to an embodiment of the present invention. FIG. 2 is an explanatory view of the hot water-refrigerant heat exchanger 14. FIG. 3 is an explanatory diagram of another configuration of the cooling circuit. FIG. 4 is an explanatory diagram of another configuration of the cooling circuit. 10 heat recovery heat pump, 11 gas engine (combustion engine), 12 cooling circuit, 13 radiator (fourth
Heat exchanger), 14 ... hot water-refrigerant heat exchanger (third heat exchanger), 14a ... first working chamber, 14b ... second working chamber, 17 ...
Compressor, 18 four-way valve, 19 indoor heat exchanger (first heat exchanger), 21 receiver, 24 outdoor heat exchanger (second heat exchanger), 25 accumulator , 28 ……
1st check valve, 30 ... 2nd check valve, 31 ... Control valve, 32 ...
Control means.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F25B 27/02 F25B 27/00

Claims (2)

(57) [Claims] 1. A combustion engine, a compressor driven by the combustion engine, a first heat exchanger connected to the compressor, and a second heat exchanger connected to an expansion valve connected to the first heat exchanger. A heat exchanger, a refrigerant circuit including the compressor connected to the second heat exchanger, a third heat exchanger circulating in the combustion engine and connected in parallel with the combustion engine, and a fourth heat exchanger. A cooling circuit including a heat exchanger, wherein the third heat exchanger includes a first working chamber and a second working chamber, and the first working chamber includes a first working chamber that circulates in a refrigerant circuit. A working fluid is introduced, a second working fluid circulating in the cooling circuit is introduced into the second working chamber, and a suction side of the first working chamber is between the first heat exchanger and the expansion valve. Is connected via a first check valve to the compressor on the discharge side of the first working chamber. Is connected to the discharge side of the compressor via a second check valve, and is connected to the suction side of the compressor via a control valve controlled to be opened and closed by control means. The control valve is introduced into the first working chamber. An exhaust heat recovery type heat pump, wherein the control means controls opening and closing based on a state of the first working fluid. 2. The control means according to claim 1, wherein
The control valve is opened when the working fluid is completely evaporated, and the control valve is closed when the first working chamber is filled with the first working fluid. Item (1): An exhaust heat recovery type heat pump according to Item (1).