JPH0240462A - Engine-driven type heat pump device - Google Patents

Abstract

PURPOSE:To show proper ability in each refrigerant circulating circuit by opening bypass valves of bypass circuits corresponding to compressors when the compressors exceeds the fixed discharge capacity. CONSTITUTION:Bypass valves 29, 129 are provided in bypass circuits 28, 128 connecting discharge pipes 6, 106 and suction pipes 7, 107. When compressors 5, 105 exceed the fixed discharge capacity, that is, refrigerant pressure at the discharge pipes 6, 106 exceeds the fixed value, the bypass valves 29, 129 are opened by detected signals of pressure sensors 30, 130. For example, when the discharge capacity of the compressor 105 is proper and the compressor 5 exceeds the fixed discharge capacity, the bypass valve 29 is opened, the refrigerant discharged from the compressor 5 passes through the bypass valve 29 and short-circuited from the discharge pipe 6 to the suction pipe 7 to circulate. As the result, the refrigerant pressure at the discharge pipe 6 is lowered to protect the capacity of the compressor 5 from excess.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an engine-driven heat pump device in which each compressor in a plurality of independent refrigerant circulation circuits is simultaneously driven by a single engine.

(Prior Art) Some of the heat pump devices described above are conventionally configured as follows. That is, each refrigerant circulation circuit has a compressor that compresses refrigerant, and the discharge side and suction side of the compressor are connected via an outdoor heat exchanger and an indoor heat exchanger that are connected in series.

The compressors of each refrigerant circulation circuit are simultaneously driven by one engine, and the refrigerant is compressed by this to cool or heat the room via an outdoor heat exchanger.

(Problem to be Solved by the Invention) By the way, when a plurality of independent refrigerant circulation circuits are provided, the cooling or heating capacity required of each refrigerant circulation circuit differs depending on the operating state. It is something. For this reason, when multiple compressors are driven by one engine at the same time as in the conventional configuration described above, if the compressors are in a group and the capacity of the refrigerant circulation circuit of one of them is appropriate, When the compressor is driven, the capacity of the other refrigerant circulation circuit becomes too large or too small, which is a disadvantage.

(Objective of the Invention) This invention was made in view of the above-mentioned circumstances, and even when each compressor of a plurality of refrigerant circulation circuits is driven simultaneously by one engine, each The purpose is to enable each circuit to demonstrate its appropriate capabilities.

Further, even in the case described above, it is an object of the present invention to enable each compressor of each refrigerant circulation circuit to be operated with an appropriate discharge capacity.

Furthermore, in order to make heating more effective, if waste heat from the engine is given to each of the refrigerant circulation circuits mentioned above, this waste heat can be rationally distributed to each refrigerant circulation circuit so that its use is not wasted. The purpose is to ensure that it is carried out.

(Structure of the Invention) A feature of the present invention for achieving the above object is that a bypass circuit is provided for each compressor to connect its discharge side and suction side via a bypass valve, so that the compressor When the discharge capacity is exceeded, the bypass valve of the bypass circuit corresponding to this compressor is opened.

In addition, in each refrigerant circulation circuit configured as described above, a superheat prevention circuit is provided that connects the outdoor heat exchanger and the indoor heat exchanger with the suction side of the compressor via a superheat prevention valve, and the refrigerant on the suction side is The feature is that the overheat prevention valve is opened when the temperature exceeds a predetermined value.

Furthermore, in each of the above configurations, an engine cooling circuit for cooling the engine is provided, and a waste heat exchanger is provided for each refrigerant circulation circuit to transmit the temperature of the cooling water of the engine cooling circuit to the refrigerant of each refrigerant circulation circuit, A cooling water valve is installed in each pipe of the engine cooling circuit that goes to each waste heat heat exchanger, and when the compressor exceeds a predetermined discharge capacity, the cooling water valve corresponding to this compressor is closed. That's what I did.

(for production) The effects of the above configuration are as follows.

Its discharge pipe (discharge side) 6.10 for each compressor 5.105
6 and the suction pipe (suction side) 7,107 with the bypass valve 29,
Provide a bypass circuit 28.128 connecting via 129,
When the compressor 5.105 exceeds a predetermined discharge capacity, the bypass circuit 28.128 corresponding to this compressor 5.105
Bypass valves 29 and 129 are opened, so if one engine l were to drive compressors 5 and 105 of the subcommittee at the same time, the discharge capacity of one compressor 105 would be appropriate and that of the other. When the compressor 5 exceeds a predetermined discharge capacity, the bypass valve 29 corresponding to the other compressor 5 opens, and the refrigerant discharged from the compressor 5 passes through the bypass circuit 28 and the bypass valve 29 and is compressed. machine 5
The air is short-circuited and circulated from the discharge pipe (discharge side) 6 to the suction pipe (suction side) 7. Then, the above discharge pipe (discharge side)
The pressure in the other compressor 5 decreases, so that the pressure in the other compressor 5
This prevents the discharge capacity from becoming excessive.

By the way, as mentioned above, the refrigerant discharged from the compressor 5.105 flows through the bypass circuit 28.128 and the bypass valve 29.
129 to the compressor 5.105 discharge pipe (discharge side) 6
．． If the refrigerant circulates in a short circuit from 106 to the suction pipe (suction side) 7.107 and continues for a long time, the temperature of this refrigerant may rise and become excessively high. This is not preferable because it unnecessarily increases the load on the compressor 5.105.

Therefore, in addition to the above configuration, the outdoor heat exchanger IO, 11
0 and indoor heat exchanger 11. Ill and the compressor 5, 1
05 suction pipe (suction side) 7.107 and overheat prevention valve 33
．． It is preferable to provide an overheat prevention circuit 32.132 connected through the above-mentioned suction pipe (suction side) 7.107, and open the overheat prevention valve 33.133 when the refrigerant temperature in the suction pipe (suction side) 7.107 reaches a predetermined value or higher. . According to this, when the temperature of the refrigerant becomes high as described above, the overheating prevention valve 33, 133 opens and is located between the outdoor heat exchanger IO, 110 and the indoor heat exchanger 11.111. The coolant refrigerant passes through the superheat prevention valve 33.133 and flows into the discharge pipe (discharge side) 6.106, thereby lowering the temperature of the refrigerant and preventing this temperature from becoming too high. .

Furthermore, in each of the above configurations, in order to make heating more effective, an engine cooling circuit 37 for cooling the engine 1 is provided, and the temperature of the cooling water in the engine cooling circuit 37 is adjusted to the temperature of the cooling water in each of the refrigerant circulation circuits 3 and 103. Transfer waste heat heat exchanger 45.
145 may be provided for each refrigerant circulation circuit 3.103. In this case, each waste heat exchanger 45.1
A cooling water valve 48.148 is provided in each pipe line of the engine cooling circuit 37 toward the engine cooling circuit 37, and when the compressor 5, 105 exceeds a predetermined discharge capacity, this compression F! i5.

If the cooling water valves 48 and 148 corresponding to 105 are closed, for example, heating by the indoor heat exchanger Ill of the second refrigerant circulation circuit 103 becomes excessive and the discharge capacity of the pressure m machine 105 exceeds a predetermined value. When this occurs, the cooling water valve 48 is closed, and heat from the cooling water is no longer transferred to the refrigerant in the second refrigerant circulation circuit 103. Then, that amount of heat will be given to the refrigerant in the first refrigerant circulation circuit 3.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

The figure is a diagram showing an air conditioner as an example of an engine-driven heat pump device.

In the figure, l is an engine, and this engine 1 is driven by gas fuel such as city gas or propane gas. 2
is the starting motor of this engine 1.

Further, the device has two mutually independent first and second refrigerant circulation circuits 3.103, both of which are operated simultaneously by the engine 1.

Since the two refrigerant systems 3 and 103 have almost the same configuration, the first refrigerant circulation circuit 3 will be mainly explained, and the second refrigerant circulation circuit 103 will be described with reference numerals corresponding to the first refrigerant circulation circuit 3 (e.g. , 5 (corresponding to 105) in the drawings, and the explanation thereof will be omitted.

The first refrigerant circulation circuit 3 has a compressor 5 driven by the engine l. The compressor 5 compresses a refrigerant such as fluorocarbon into a high-temperature, high-pressure gas. The discharge side of this compressor 5 is equipped with a discharge pipe 6, and the suction side is equipped with a suction pipe 7. Further, a four-way switching valve 8 is interposed between the discharge pipe 6 and the suction pipe 7.

An outdoor heat exchanger 1O is provided outdoors, and a pair of indoor heat exchangers 11, 11 are provided in parallel indoors. The four-way switching valve 8 and the outdoor heat exchanger lO are connected by a first pipe 12, the outdoor heat exchanger lO and the indoor heat exchanger 11.11 are connected by a second pipe 13, and the above-mentioned Four-way switching valve 8 and indoor heat exchanger 11. ll is the third pipe 1
Connected by 4. In the above case, the first refrigerant circulation circuit 3
A common fan 15.15 is provided for the outdoor heat exchanger IO and the outdoor heat exchanger 110 of the second refrigerant circulation circuit 103, so that forced heat exchange with the outside air is performed. There is.

An oil separator 16 is interposed in the middle of the discharge pipe 6, and this oil separator 16 separates the oil in the discharge pipe 6 and returns this oil to the suction pipe 7 through an oil return pipe 17. Further, a liquid separator 18 is interposed in the middle of the suction pipe 7, and this liquid separator 18 separates liquid from the refrigerant passing through the suction pipe 7, and causes only gas to be sucked into the compressor 5. Make it. Furthermore, an expansion valve 20 is installed in the middle of the second pipe 13,
Check valves 21, 22, 23 and also a liquid receiver 24 are provided.

In the first refrigerant circulation circuit 3 described above, the four-way switching valve 8 is operated to bring it into the state shown by the solid line in the figure, and the engine 1 operates the compressor 5.
When driven, the first refrigerant circulation E circuit 3 becomes a cooling circuit as shown by the solid arrow in the figure.

That is, the refrigerant is compressed by the compressor 5 and becomes a high-temperature, high-pressure gas, which is then passed through the discharge pipe 6, the four-way switching valve 8, and the first pipe 12.
and is sent to the outdoor heat exchanger IO. This refrigerant radiates heat and condenses into a high-pressure liquid, which passes through the check valve 22 and is temporarily stored in the liquid receiver 24.
It is fed into each indoor heat exchanger 7311.11. and,
The refrigerant is depressurized here and evaporated into a low-temperature, low-pressure atomized state, and at this time the indoor heat exchanger 11.11 cools the room. Further, this refrigerant passes through the third pipe 14, the four-way switching valve 8, the suction pipe 7, and the liquid separator 18 to the compressor 5.
The cycle is completed.

On the other hand, when the four-way switching valve 8 is switched to the state shown by the phantom line in the figure, the first refrigerant circulation circuit 3 becomes a heating circuit as shown by the phantom line arrow in the figure, contrary to the above.

That is, after the refrigerant is compressed by the compressor 5 and becomes a high-temperature, high-pressure gas, the discharge pipe 6, the four-way switching valve 8, and the third pipe 14
and into each indoor heat exchanger 11.11. The indoor heat exchanger 11.11 heats the room, and at this time, the refrigerant condenses into a high-pressure liquid.
This refrigerant passes through the check valve 23, the liquid receiver 24, the expansion valve 20, and the second pipe 13, and is sent to the outdoor heat exchanger "alO", where it is given heat and becomes a gas.
After that, this is the first pipe 12, the four-way switching valve 8, and the suction pipe 7.
, and returns to the compressor 5 through the liquid separator 18 to complete the cycle.

On the other hand, the indoor heat exchanger 1 is connected to the second refrigerant circulation circuit 103.
Only one indoor heat exchanger Ill having the same capacity as No. 1 is provided.

In the above configuration, a bypass circuit 28 is provided that connects the discharge pipe 6 and the suction pipe 7, and this bypass circuit 28 has a bypass valve 29 in the middle thereof. Further, a pressure sensor 30 is provided to detect the pressure of the refrigerant in the discharge pipe 6. Then, when the discharge capacity of the compressor 5 increases and the compressor 5 exceeds a predetermined discharge capacity, that is,
When the pressure of the refrigerant in the discharge pipe 6 exceeds a predetermined value, a detection signal from the pressure sensor 30 causes the bypass valve 29 to be closed. Note that this detection signal may be electrical or electronic, or may be physical such as directly transmitting pressure through piping. This also applies to each detection signal described later.

Then, for example, if the discharge capacity of the compressor 105 of the second refrigerant circulation circuit 103 is appropriate, and on the other hand, the compressor 5 of the first refrigerant circulation circuit 3 exceeds a predetermined discharge capacity, then the other compressor The bypass valve 29 corresponding to the compressor 5 opens, and the refrigerant discharged from the compressor 5 passes through the bypass circuit 28 and the bypass valve 29, and is short-circuited from the discharge pipe 6 of the compressor 5 to the suction pipe 7. becomes. Then, the pressure of the refrigerant in the discharge pipe 6 decreases, and therefore, the capacity of the other compressor 5 is prevented from becoming excessive.

By the way, as mentioned above, the refrigerant discharged from the compressor 5 passes through the bypass circuit 28 and the bypass valve 29, and circulates from the discharge pipe 6 of the compressor 5 to the suction pipe 7, and if this continues for a long time, this The temperature of the refrigerant may rise and become too high. This undesirably increases the load on the compressor 5 unnecessarily.

Therefore, in order to prevent the above-mentioned inconvenience, a first-order configuration is adopted. That is, in addition to the above configuration, a superheat prevention circuit 32 is provided that connects the suction pipe 7 and the second pipe 13, and a superheat prevention valve 33 and an electromagnetic on-off valve 34 are provided in the middle of this superheat prevention circuit 32. are interposed in series.

In the above case, the operation of the on-off valve 34 is to open the bypass valve 29,
It is made to coincide with the valve closing operation.

Further, the connection portion of the overheat prevention circuit 32 to the suction pipe 7 is closer to the compressor 5 than the connection portion of the oil return pipe 17 to the suction pipe 7, and furthermore, the connection portion of the overheat prevention circuit 32 to the suction pipe 7 is closer to the compressor 5 than the connection portion of the oil return pipe 17 to the suction pipe 7. A temperature sensing tube 35 is provided to detect the temperature of the refrigerant. When the temperature of this refrigerant becomes too high and exceeds a predetermined temperature, the overheat prevention valve 33 is opened in response to a detection signal from the temperature sensing cylinder 35.

Then, as described above, when the temperature of the refrigerant in the suction pipe 7 becomes high and the overheating prevention valve 33 is opened by the temperature sensing tube 35, the The refrigerant with a low target temperature is the second pipe 13,
Overheat prevention circuit 32, overheat prevention valve 33, and on-off valve 34
The refrigerant flows into the discharge pipe 6 through the refrigerant, thereby lowering the temperature of the refrigerant in this portion to prevent the temperature from becoming excessively high.

On the other hand, the engine 1 is provided with an engine cooling circuit 37 for cooling the engine.

That is, a cooling water passage 38 is formed in the engine 1, and a pump 3 pumps cooling water into the cooling water passage 38.
9 is provided. Further, a radiator 42 is provided between an outlet pipe 40 extending from the cooling water passage 38 and an inlet pipe 41 connected to the suction side of the pump 39, and this radiator 42 is also installed outside the fan 15. It is now forced to cool down.

When cooling water is sent into the cooling water passage 38 by the pump 39, the engine 1 is cooled, and the high temperature cooling water is cooled by the radiator 42 and returned to the pump 39.

Further, in the above configuration, the first and second refrigerant circulation rQ circuits 3
．． When 103 is used as a heating circuit, it is configured as follows in order to make it more effective.

That is, when the first and second refrigerant circulation circuits 3.103 are used as heating circuits as shown by the imaginary line arrows in the figure, the temperature of the cooling water in the engine cooling circuit 37 is adjusted to A double-tube waste heat heat exchanger 45 is provided which communicates to the circulation circuit 3.103.

On the other hand, a thermostat 46 is interposed in the middle of the outlet pipe 40, and extends from the thermostat 46 to the inlet pipe 4.
A waste heat pipe 47 connected to 1 is provided. The waste heat exchanger 45 is configured to transmit the temperature of the cooling water in the waste heat pipe 47 to the refrigerant in the first pipe 12.

Therefore, the driving of the compressor 5.105 by the engine 1 can be suppressed by the amount of heat given to the refrigerant from the cooling water in the first pipe 12, thereby effectively performing heating.

In the above case, the waste heat pipe 47 is provided with an electromagnetic cooling water valve 4.
8 is provided. This cooling water valve 48 operates in the opposite direction to the bypass valve 29 and the on-off valve 34, and when the compressor 5 exceeds a predetermined discharge capacity, that is, the pressure of the refrigerant in the discharge pipe 6 reaches a predetermined level. When the value is exceeded, the cooling water valve 48 is closed by the detection signal from the pressure sensor 3o.

Therefore, for example, when the heating by the indoor heat exchanger 111 of the second refrigerant circulation circuit 103 becomes excessive and the discharge capacity of the compressor 105 exceeds a predetermined value, the cooling water valve 48 is closed and the second refrigerant Heat is no longer transferred from the cooling water to the refrigerant in the circulation circuit 103. Therefore, that amount of heat is given to the refrigerant in the first refrigerant circulation circuit 3, thereby effectively performing heating.

Although the above is based on the illustrated example, there may be three or more refrigerant circulation circuits.

(Effects of the Invention) According to the present invention, a bypass circuit is provided for each compressor to connect its discharge side and suction side via a bypass valve, and when the compressor exceeds a predetermined discharge capacity, the compressor By opening the bypass valves of the bypass circuits corresponding to the bypass circuits, even if one engine were to drive the compressors of each section at the same time, one compressor's discharge capacity would be appropriate and the other compressor would be at the specified level. If the discharge capacity of the other compressor is exceeded, the bypass valve corresponding to this other compressor opens, and the refrigerant discharged from this compressor passes through the bypass circuit and bypass valve and is short-circuited from the discharge side to the suction side of the compressor. It will be circulated. Then, the pressure on the discharge side decreases, and therefore, the discharge capacity of the other compressor is prevented from becoming excessive. As a result, the capacities of both refrigerant circulation circuits are maintained appropriately.

In addition to the above configuration, a superheat prevention circuit is provided that connects the outdoor heat exchanger and indoor heat exchanger with the suction side of the compressor via a superheat prevention valve, so that the refrigerant temperature on the suction side is maintained at a predetermined value. It is preferable to open the overheating prevention valve when the temperature of the refrigerant becomes high. According to this, the refrigerant is short-circuited and circulated as described above, and therefore, when the temperature of the refrigerant becomes high, the overheating prevention valve is opened. The prevention valve opens and the refrigerant, which is located between the outdoor heat exchanger and the indoor heat exchanger and has a relatively low temperature, passes through the overheat prevention valve and flows into the discharge side. Therefore, the temperature of the refrigerant is lowered, and this temperature is lowered. is prevented from becoming excessively high.

Therefore, each compressor will be operated in an appropriate state.

In addition, in each of the above configurations, in order to make heating more effective, an engine cooling circuit is provided to cool the engine, and a waste heat heat exchanger is installed to transfer the temperature of the cooling water of this engine cooling circuit to the refrigerant of each refrigerant circulation circuit. may be provided for each refrigerant circulation circuit. In this case, a cooling water valve is installed in each pipe of the engine cooling circuit toward each waste heat heat exchanger, so that when the compressor exceeds a predetermined discharge capacity, the cooling water corresponding to this compressor is If the valve is closed, for example, when the heating by the indoor heat exchanger in one refrigerant circulation circuit becomes excessive and the discharge capacity of the compressor exceeds a predetermined value, the cooling water valve is closed and the refrigerant is discharged. Heat from the cooling water is no longer transferred to the refrigerant in the circulation circuit. and,
That amount of heat will be given to the refrigerant in the other refrigerant circulation circuit, and as a result, waste heat from the engine will be rationally distributed to each refrigerant circulation circuit and used without waste. .

[Brief explanation of the drawing]

FIG. 1 is an overall diagram of an embodiment of the present invention. l...engine, 3...first refrigerant circulation circuit, 5.105
...Compressor, 6.106...Discharge pipe (discharge side), 7.1
07... Suction pipe (suction side), 10.110... Outdoor heat exchanger, 11.1-11... Indoor heat exchanger, 28.128... Passage, 29.129... Bypass valve, - Overheating prevention circuit, 33.133 Valve, 37... Engine cooling circuit, 4 - Waste heat exchanger, 48,148. 103... Second refrigerant circulation circuit.・Bypass circuit 32.132 ・・Overheat prevention 5.145・・Cooling water valve,

Claims (1)

[Claims] 1. A plurality of refrigerant circulation circuits are provided for one engine, and the compressors for refrigerant compression provided in each refrigerant circulation circuit are simultaneously driven by the engine and connected in series. In an engine-driven heat pump device in which the discharge side and suction side of each compressor are connected via an outdoor heat exchanger and an indoor heat exchanger, the discharge side and suction side of each compressor are connected. This engine-driven heat pump device is equipped with a bypass circuit that connects the compressor with the compressor via a bypass valve, and when the compressor exceeds a predetermined discharge capacity, the bypass valve of the bypass circuit corresponding to the compressor is opened. 2. In each refrigerant circulation circuit, a superheat prevention circuit is provided that connects the outdoor heat exchanger and indoor heat exchanger with the suction side of the compressor via a superheat prevention valve, so that the refrigerant temperature on the suction side is maintained at a predetermined level. 2. The engine-driven heat pump device according to claim 1, wherein the overheat prevention valve is opened when the temperature exceeds a certain value. 3. An engine cooling circuit is provided to cool the engine, and each refrigerant circulation circuit is provided with a waste heat heat exchanger that transfers the temperature of the cooling water in this engine cooling circuit to the refrigerant in each refrigerant circulation circuit. A cooling water valve is provided in each pipe of the engine cooling circuit toward the exchanger, and when the compressor exceeds a predetermined discharge capacity, the cooling water valve corresponding to the compressor is closed. 2. The engine-driven heat pump device according to 2.