JP2001248489A - Method for controlling engine heat pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a recovery rate of exhaust heat of an engine and to perform a stable operation control, in an engine heat pump. SOLUTION: A temperature control of exhaust gas of the engine 3 is performed. The temperature control of exhaust gas is performed by ignition timing of the engine 3, a fuel-air ratio of fuel and a recirculation rate of exhaust gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an air conditioner in which a compressor is driven by an engine.

[0002]

2. Description of the Related Art Conventionally, an engine heat pump using exhaust heat of an engine has been known, and many techniques for improving heating efficiency have been disclosed. These use the air around the engine warmed by the engine or warm the refrigerant with the cooling water of the engine. Further, as shown in Japanese Patent Application Laid-Open No. 5-2772838, there is known an apparatus in which a refrigerant tank is mounted on an upper portion of an engine to heat the refrigerant.

[0003]

In any of the above techniques, the exhaust heat from the engine cannot be fully utilized. In the technique disclosed in JP-A-5-272838, since the refrigerant is introduced around the cylinder of the engine, the mechanism becomes complicated, and there is a problem in maintainability. Furthermore, it does not sufficiently recover the heat of the exhaust gas.

[0004]

In order to solve the above-mentioned problems, the following means are used. First,
As described in claim 1, the temperature of the exhaust gas supplied to the heat exchanger is adjusted.

According to the present invention, the ignition timing of the engine is controlled by the temperature of the exhaust gas.

According to a third aspect of the present invention, the air-fuel ratio of the engine is adjusted according to the temperature of the exhaust gas.

The EGR valve is controlled based on the temperature of the exhaust gas.

According to a fifth aspect of the present invention, the path of the exhaust gas connected to the heat exchanger is changed according to the temperature of the exhaust gas.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an exhaust heat recovery circuit diagram showing a basic configuration of utilizing exhaust heat of an engine, FIG. 2 is a diagram showing a configuration of an exhaust gas heat exchanger and a second sub heat exchanger, and FIG.
Is a diagram showing a configuration of a second sub heat exchanger, FIG. 4 is a diagram showing a first embodiment of a refrigerant circuit and an exhaust heat recovery circuit, FIG. 5 is a diagram showing a refrigerant circuit and a cooling water circuit of the first embodiment, 6 is a diagram showing a second embodiment of the refrigerant circuit and the exhaust heat recovery circuit, FIG. 7 is a diagram showing a third embodiment of the refrigerant circuit and the exhaust heat recovery circuit, FIG.
Is a diagram showing a fourth embodiment of the refrigerant circuit and the exhaust heat recovery circuit,
9 is a diagram showing a connection configuration of a controller, FIG. 10 is a diagram showing a configuration for controlling exhaust gas temperature, FIG. 11 is a diagram showing a configuration in which a bypass pipe is connected to an exhaust pipe, and FIG. 12 is an exhaust gas flow rate to the bypass pipe. It is a figure showing composition of adjustment.

The basic structure of the exhaust heat recovery circuit will be described with reference to FIG. The refrigerant circuit 12 mainly includes the compressor 7, the four-way valve 19, the indoor heat exchanger 23, the expansion valve 24, and the outdoor heat exchanger 22. And in the refrigerant circuit 12, between the compressor 7 and the outdoor heat exchanger 22,
The first sub heat exchanger 25 and the second sub heat exchanger 9 are arranged. The four-way valve 19 shown in FIG. 1 is set to a heating state, and cooling is performed by switching the four-way valve 19 and reversing the supply direction of the refrigerant. When the cooling is performed, the refrigerant is supplied from the compressor 7 to the outdoor heat exchanger 22 by the switching of the circuit, without passing through the first sub heat exchanger 25 and the second sub heat exchanger 9. is there.

Next, the flow of heat into and out of the refrigerant during the heating of the refrigerant circuit 12 will be described. The compressor 7 driven by the engine 3 supplies the refrigerant to the indoor heat exchanger 23 via the four-way valve 19. The refrigerant releases heat in the indoor heat exchanger 23 and is introduced into the outdoor heat exchanger 22 via the expansion valve 24. In the outdoor heat exchanger 22, the refrigerant absorbs heat from outside air. Thereafter, in the second sub heat exchanger 9 and the first sub heat exchanger 25, the refrigerant absorbs heat from the exhaust gas and the engine cooling water, and
It is to return to. Thereby, the gas heat pump heats the room.

The first sub heat exchanger 25 is connected to the exhaust gas heat exchanger 51 and the water jacket of the engine 3 by the cooling water circuit 20. The exhaust gas heat exchanger 51 is connected to an exhaust pipe, and absorbs heat of the exhaust gas by cooling water. The second auxiliary heat exchanger 9 is connected to the exhaust pipe, and absorbs the heat of the exhaust gas by the refrigerant. That is, when the refrigerant circuit 12 is heated,
The refrigerant is supplied with heat from the outdoor heat exchanger 22, the second sub heat exchanger 9, and the first sub heat exchanger 25. On the other hand, the heat of the exhaust gas is absorbed in the exhaust gas heat exchanger 51 and the second sub heat exchanger 9. In the above configuration, the first sub heat exchanger 25 and the second sub heat exchanger 9 are connected in series to the refrigerant circuit 12, but are connected in parallel and It is also possible to configure so that the flow rate of the refrigerant to the secondary heat exchanger 9 can be adjusted.

Next, a description will be given of heat absorption from exhaust heat by using the above-described configuration in the gas heat pump with reference to FIG. FIG. 2A shows a heat recovery configuration of the exhaust gas, and FIG. 2B shows a temperature difference between the exhaust gas, the refrigerant, and the cooling water. In FIG. 2A, the cooling water and the refrigerant flow into the exhaust gas heat exchanger 51 and the second sub heat exchanger 9 from the downstream side of the exhaust gas, respectively.
It flows out from the upstream side.

When the exhaust gas heat exchanger and the second auxiliary heat exchanger are used, the heat of the exhaust gas is absorbed by the cooling water of the engine 3 and then the heat of the exhaust gas is further absorbed by the refrigerant. . Therefore, as shown in FIG. 2B, in the first half of the exhaust gas path where the temperature of the exhaust gas is sufficiently high, the heat of the exhaust gas is absorbed by the cooling water, and in the second half of the path where the temperature of the exhaust gas is low, Absorbs the heat of exhaust gas. Therefore, an effective temperature difference can be obtained even in the latter half of the exhaust gas path, and the calorific value of the exhaust gas can be sufficiently absorbed.

Further, as shown in FIG. 2B, the exhaust gas is cooled to 100 ° C. or less by a refrigerant. Exhaust gas generated by combustion of hydrocarbons as fuel contains a large amount of water vapor, and a part of this water vapor is liquefied by being cooled to 100 ° C. or lower. For this reason, the second sub heat exchanger 9
When the exhaust gas is cooled in the above, water vapor is condensed on the outer peripheral surface of the refrigerant pipe through which the low temperature refrigerant flows. The water vapor liquefies to generate latent heat, and the latent heat is transmitted to the refrigerant via the refrigerant pipe, thereby warming the refrigerant. That is, by absorbing the calorific value of the exhaust gas by the refrigerant, the water vapor contained in the exhaust gas is liquefied, and the resulting latent heat can be used for heating the refrigerant. Since heat can be efficiently transmitted from the exhaust gas to the cooling water and the refrigerant, the path length in the heat exchanger can be shortened, and the heat exchanger can be made compact.

The configuration of the second sub heat exchanger 9 will be described with reference to FIG. FIG. 3A is a schematic diagram illustrating a configuration of the second sub heat exchanger, and FIG. 3B is a cross-sectional view of the second sub heat exchanger. The second sub heat exchanger 9, which heats the refrigerant by the heat of the exhaust gas, includes a refrigerant pipe 9b, an outer pipe 9a, and a drain 9c. A plurality of refrigerant tubes 9 are provided inside the outer tube 9a.
The refrigerant pipes 9b are connected to each other at their ends. The refrigerant is introduced from one end of the refrigerant pipe 9b and flows out from the other end. Exhaust gas flows into the inside of the outer tube 9a, transfers heat to the refrigerant tube 9b, and is discharged. A drain 9c is provided below the second sub heat exchanger 9, and water in the exhaust gas condensed on the refrigerant pipe 9b is discharged from the drain 9c. Since the water discharged from the drain is acidic, a neutralization treatment is performed.

Next, a first embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. The compressors 7 are driven by the engine 3 and supply the refrigerant to the oil separator 21. The refrigerant and the lubricating oil are separated in the oil separator 21, and the refrigerant flowing through the oil separator 21 flows into the four-way valve 19. The four-way valve 19 shown in FIG. 5 is for heating, and cooling can be performed by switching the four-way valve 19. If the heat pump is used only for heating, the four-way valve can be omitted. The refrigerant is supplied to the indoor heat exchangers 23 via the four-way valve 19. An indoor heat exchanger 23 is connected to the refrigerant circuit 12 in parallel.
The refrigerant is supplied to each of 23. Then, in the indoor heat exchangers 23, the heat of the refrigerant is released into the room to perform heating.

The refrigerant having passed through the indoor heat exchangers 23 is supplied to the outdoor heat exchanger 22 via the expansion valves 24 and the liquid receiver 13, respectively. put it here,
The liquid receiver 13 is not always necessary,
It is installed according to the scale and configuration of the engine heat pump. The refrigerant via the liquid receiver 13 is supplied to the outdoor heat exchanger 22 via the expansion valve 61. Thereafter, the heat is supplied to the first sub heat exchanger 25 via the second sub heat exchanger 9 and the four-way valve 19. The waste heat of the engine 3 is supplied to the refrigerant by the second sub heat exchanger 9 and the first sub heat exchanger 25. Then, the refrigerant is introduced into the accumulator 16 via the first sub heat exchanger 25, and is supplied again to the compressors 7,7.

Next, the path of the exhaust gas in the first embodiment will be described. The exhaust gas of the engine 3 is introduced into the exhaust gas heat exchanger 51 and is cooled by cooling water for cooling the engine 3. Then, it is introduced into the second sub heat exchanger 9 and further cooled by the refrigerant. The cooling water of the engine 3 includes the exhaust gas heat exchanger 51 and the engine 3
The water jacket absorbs heat and warms the refrigerant in the first sub heat exchanger 25.

In the refrigerant circuit of the first embodiment, the second sub heat exchanger 9 and the first sub heat exchanger 25 are connected in series, and the refrigerant warmed in the second sub heat exchanger 9 It is introduced into one sub heat exchanger 25 and further warmed. Thereby, the exhaust heat of the engine 3 can be efficiently used for heating, and the fuel for heating can be saved.

The configuration of the cooling water circuit of the engine heat pump shown in the first embodiment will be described in more detail with reference to FIG. In FIG. 5, the cooling water circuit 20 is indicated by a thick line. The cooling water is pumped through the cooling water circuit 20.
The cooling water that has been circulated through the engine 9 and has become hot in the engine 3 is cooled by the radiator 26. Further, by switching the three-way valve 28, the high-temperature cooling water is guided to the second sub heat exchanger 25, so that heat can be given to the refrigerant. The cooling water circuit 20 is provided with a thermostat 27 so that when the temperature of the cooling water is not so high and cooling is not required, the cooling water returns directly to the engine 3 without passing through the radiator 26. ing. As described above, the cooling water circuit 20 is provided with the exhaust gas heat exchanger 51, and is configured to exchange heat between the exhaust gas from the engine 3 and the cooling water.

Next, the structure of the engine heat pump of the second embodiment will be described with reference to FIG. In the refrigerant circuit of the second embodiment, the first sub heat exchanger 25 and the second sub heat exchanger 9 are connected in parallel. The first sub heat exchanger 25 and the second sub heat exchanger 9 are connected in parallel to the refrigerant circuit between the outdoor heat exchanger 22 and the compressor 7, and the refrigerant to the second sub heat exchanger 9 is connected by the solenoid valve 64. It controls the inflow of water. That is, the solenoid valve 6
According to 4, refrigerant can be introduced into both the first sub heat exchanger 25 and the second sub heat exchanger 9 or only into the first sub heat exchanger 25.

In the refrigerant circuit of the second embodiment, the refrigerant is supplied by the compressor 7 to the indoor heat exchangers 23 via the four-way valve 19 and supplied to the outdoor heat exchanger 22 via the expansion valve 24. Then, the refrigerant via the outdoor heat exchanger 22 is introduced into the branch 65. The first sub heat exchanger 25 and the solenoid valve 64 are connected to the branches 65, respectively. The solenoid valve 64 is connected to the second sub heat exchanger 9.
In the “open” state, the refrigerant is supplied to the second sub heat exchanger 9, and in the “closed” state, the refrigerant is prevented from flowing into the second sub heat exchanger 9. .

When the solenoid valve 64 is open and the refrigerant is supplied to both the first sub heat exchanger 25 and the second sub heat exchanger 9, the refrigerant supplied to the second sub heat exchanger 9 is supplied to the capillary. The refrigerant is supplied to the accumulator 16 via the tube 63 together with the refrigerant supplied to the first sub heat exchanger 25. Then, the structure returns to the compressor 7.

As described above, by controlling the solenoid valve 64, the refrigerant can control the introduction of the refrigerant into the first sub heat exchanger 25 and the second sub heat exchanger 9, so that the amount of heat given to the refrigerant can be easily adjusted. I can do it. Since the first sub heat exchanger 25 and the second sub heat exchanger 9 are connected in parallel in the refrigerant circuit,
The circulation resistance of the refrigerant can be reduced, and the efficiency of supplying heat to the refrigerant is improved. Further, generation of dew water from exhaust gas can be adjusted.

Next, a third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In the third embodiment, the outdoor heat exchanger 22 and the second sub heat exchanger 9 are connected in parallel in the refrigerant circuit. In the refrigerant circulation path at the time of heating, the refrigerant circuit is branched on the downstream side of the indoor heat exchanger 23 into a path leading to the outdoor heat exchange 22 and a path leading to the second sub heat exchanger 9.

The refrigerant introduced into the path leading to the outdoor heat exchange 22 is introduced into the first auxiliary heat exchanger 25 via the outdoor heat exchange 22 and the four-way valve 19. When the solenoid valve 64 is open, the refrigerant introduced into the path leading to the second sub heat exchanger 9 passes through the capillary tube 63 via the second sub heat exchanger 9 and the first sub heat exchanger. 25. The refrigerant that has passed through the outdoor heat exchanger 22 or the outdoor heat exchanger 22 and the second sub heat exchanger 9 is returned to the compressor 7 via the accumulator 16.

With the above configuration, the refrigerant is supplied to the outdoor heat exchanger 2
2, or can be supplied to the outdoor heat exchanger 22, the second sub heat exchanger 9, and the first sub heat exchanger 25. As a result, the refrigerant path can be easily switched using the solenoid valve 64 and the circulation resistance of the refrigerant can be reduced.
The efficiency of supplying heat to the refrigerant is improved.

Next, a fourth embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In the fourth embodiment, the outdoor heat exchanger 22 and the second sub heat exchanger 9 are connected in parallel, and an electronic flow control valve 66 is provided in a refrigerant circuit leading to the second sub heat exchanger 9. The amount of the refrigerant supplied to the second sub heat exchanger 9 is continuously adjusted by the electronic flow control valve 66.
The refrigerant circuit is branched on the upstream side of the expansion valve 61 during heating, and the refrigerant via the indoor heat exchanger 23 is supplied to the expansion valve 61 and the electronic flow control valve 66, respectively.
The refrigerant via the electronic flow control valve 66 is supplied to the first sub heat exchanger 25 via the second sub heat exchanger 9. Since the amount of the refrigerant can be continuously adjusted by the electronic flow control valve 66,
It is possible to adjust the amount of heat supplied to the refrigerant in the second sub heat exchanger 9. Thereby, the degree of cooling of the exhaust gas can be adjusted. The refrigerant that has passed through the expansion valve 61 is supplied to the first sub heat exchanger 25 via the outdoor heat exchanger 22.

Next, the control configuration of the engine 3 will be described with reference to FIG. The engine control configuration described below can be used in each of the above-described embodiments. The air sucked from the air cleaner 75 is introduced into the fuel supply device 74, and is supplied to the engine 3 through the throttle valve 73 as an air-fuel mixture mixed with the fuel.
Is introduced into the combustion chamber. The air-fuel mixture compressed in the combustion chamber is burned by the spark of the ignition plug 72 and then discharged through the exhaust pipe 71.

An exhaust gas temperature sensor 76 is attached to the exhaust pipe 71 so that the temperature of the exhaust gas in the exhaust pipe 71 can be detected. The exhaust temperature sensor 76 is connected to the exhaust pipe 7
1, it is also possible to detect the exhaust gas temperature by heat conduction, and it is also possible to dispose it inside the exhaust pipe 71 to detect the exhaust gas temperature. Further, a recirculation pipe 78 is connected to the exhaust pipe 71, so that the exhaust gas introduced into the exhaust pipe 71 can be supplied to the upstream side of the throttle valve 73. An electromagnetic valve 77 is provided on the exhaust gas introduction side of the recirculation pipe 78, and the supply of exhaust gas to the throttle valve 73 can be adjusted by opening and closing the electromagnetic valve 77.

Fuel supply device 74, throttle valve 7
3. The ignition plug 72, the exhaust temperature sensor 76, and the electromagnetic valve 77 are controlled by the controller 80. Thus, the fuel supply device 74 can adjust the air-fuel ratio of the air-fuel mixture, and the throttle valve 73 can adjust the throttle opening. The ignition plug 72 can adjust the ignition timing, and the electromagnetic valve 77 can adjust the opening and closing.

The engine 3 is detected by the exhaust temperature sensor 76.
Is detected, and the detected value of the exhaust gas temperature sensor 76 is output to the controller 80.
In the controller 80, calculation is performed based on the detection value of the exhaust gas temperature sensor 76. Based on this result, the controller 80 controls one or more of the ignition timing by the fuel supply device 74 and the ignition plug 72 and the electromagnetic valve 77. Then, the temperature of the exhaust gas is controlled.

The position of the exhaust gas temperature sensor 76 is not particularly limited, but may be arranged near a mechanism that requires temperature control of the exhaust gas, so that the temperature of the mechanism can be controlled. is there. In this embodiment,
It is for controlling the temperature of the second sub heat exchanger 9 for transmitting the calorific value of the exhaust gas to the refrigerant. The exhaust temperature sensor 76 is disposed immediately before the exhaust gas path of the second sub heat exchanger 9, detects the temperature of the exhaust gas introduced into the second sub heat exchanger 9, and outputs the detected temperature to the controller 80. Things.

In the controller 80, a constant temperature is set, and the temperature is compared with the temperature detected by the exhaust gas temperature sensor 76. When the temperature detected by the exhaust temperature sensor 76 is higher than the set temperature, the ignition timing by the fuel supply device 74 and the ignition plug 72 and the temperature of the exhaust gas by the electromagnetic valve 77 are reduced.

Next, a control structure of the exhaust gas temperature will be described with reference to FIG. FIG. 10 (a) shows a configuration for adjusting the ignition timing, and FIG. 10 (b) shows a configuration for adjusting the air-fuel ratio. FIG. 10C shows the configuration of the exhaust gas recirculation rate adjustment. In FIG. 10A, the vertical axis indicates the temperature of the exhaust gas temperature sensor.
The horizontal axis indicates the ignition timing. In FIG. 10B, the vertical axis indicates the temperature of the exhaust gas temperature sensor, and the horizontal axis indicates the air-fuel ratio. In FIG. 10C, the vertical axis represents the temperature of the exhaust gas temperature sensor, and the horizontal axis represents the exhaust gas recirculation rate.

First, the configuration for adjusting the exhaust gas temperature by the ignition timing will be described. As described above, the exhaust temperature sensor 76 and the ignition plug 72 are connected to the controller 80. When the temperature detected by the exhaust gas temperature sensor 76 is higher than the temperature set in the controller 80, the ignition timing is advanced and the temperature of the exhaust gas is reduced. In this embodiment, the exhaust gas temperature sensor 76 is disposed immediately before the second sub heat exchanger 9 so as to control the temperature of the exhaust gas so that the refrigerant of the second sub heat exchanger 9 can be used stably. Things. The set temperature is set to 160 ° C. The set temperature is changed to the optimum temperature depending on the refrigerant to be used and the mounting position of the exhaust temperature sensor 76, and is not limited.

As shown in FIG. 10A, the temperature of the exhaust gas becomes higher than the set temperature, and the ignition timing at that time becomes t1.
In this case, the ignition timing is controlled by the controller 80, and the ignition timing becomes t2. Generally, ignition occurs shortly before reaching the top dead center at which compression of the mixture ends. For this reason, the combustion is rapidly completed by the earlier ignition timing, and the temperature of the exhaust gas after the combustion is lowered. That is, the controller 80 advances the ignition timing of the ignition plug 72 from t1 to t2, thereby lowering the temperature of the exhaust gas. Thereby, the temperature of the exhaust gas flowing into the second sub heat exchanger 9 is controlled.

Next, a mechanism for adjusting the exhaust gas temperature based on the air-fuel ratio will be described. An exhaust temperature sensor 76 and a fuel supply device 74 are connected to the controller 80. If the temperature detected by the exhaust gas temperature sensor 76 is higher than the temperature set in the controller 80, the air-fuel ratio is adjusted by the fuel supply device 74,
This is to lower the temperature of the exhaust gas.

As shown in FIG. 10B, when the temperature of the exhaust gas becomes higher than the set temperature and the air-fuel ratio is r1, the controller 80 controls the fuel supply device 74, and the air-fuel ratio becomes r2. Become. That is, the amount of air with respect to the fuel is increased. As the air-fuel ratio increases, more air is introduced into the cylinder, the combustion gas is diluted, and the temperature of the exhaust gas after combustion decreases. That is, the controller 80 controls the fuel supply device 74 to increase the air-fuel ratio introduced into the combustion chamber from r1 to r2, thereby lowering the temperature of the exhaust gas. Thereby, the temperature of the exhaust gas flowing into the second sub heat exchanger 9 is controlled.

Next, a mechanism for adjusting the exhaust gas temperature based on the exhaust gas circulation rate will be described. The controller 80 is connected to an exhaust gas temperature sensor 76 and an electromagnetic valve 77 disposed on an exhaust gas recirculation pipe 78. When the temperature detected by the exhaust gas temperature sensor 76 is higher than the temperature set in the controller 80, the exhaust gas recirculation rate is adjusted by controlling the electromagnetic valve 77 to lower the temperature of the exhaust gas. Things.

As shown in FIG. 10C, when the temperature of the exhaust gas becomes higher than the set temperature and the exhaust gas recirculation rate at that time is p1, the controller 80 controls the electromagnetic valve 77, and the electromagnetic valve 77 is controlled. The opening of the valve 77 increases. As the opening of the electromagnetic valve 77 increases, the amount of exhaust gas flowing into the exhaust gas recirculation pipe 78 increases, and the exhaust gas recirculation rate increases to p2. As the exhaust gas recirculation rate increases, the amount of exhaust gas introduced into the cylinder increases, and the combustion gas is diluted, so that the temperature of the exhaust gas after combustion decreases. That is, the controller 80 controls the electromagnetic valve 77 to increase the exhaust gas recirculation rate from p1 to p2, thereby lowering the temperature of the exhaust gas. Thereby, the temperature of the exhaust gas flowing into the second sub heat exchanger 9 is controlled.

Next, a configuration for controlling the temperature of the inflowing exhaust gas by controlling the exhaust gas supply amount will be described.
This will be described with reference to FIG. In FIG. 11, the exhaust pipe 71
Is provided with a first auxiliary heat exchange air 51 and a second auxiliary heat exchanger 9. Further, a pipe 84 that bypasses exhaust gas flowing into the second heat exchanger 9 is connected. The pipe 84 is connected to the second auxiliary heat exchanger 9 in the exhaust gas outflow path.
And are arranged in parallel. The pipe 84 is provided with a solenoid valve 83 so that exhaust gas flowing into the pipe 84 can be regulated. Similarly, a solenoid valve 82 is provided in the exhaust pipe 71 connected to the second sub heat exchanger 9 so that the exhaust gas flowing into the second sub heat exchanger 9 can be regulated.

The exhaust temperature sensor 76 is connected to the second sub heat exchanger 9.
And outputs the temperature of the exhaust gas to the controller 80. In the controller 80,
The solenoid valves 82 and 83 are connected, and the opening and closing of the solenoid valves 82 and 83 are controlled by the controller 80. That is, by reducing the opening of the solenoid valve 82, the second sub heat exchanger 9
The amount of exhaust gas introduced into the pipe 84 can be increased by reducing the amount of exhaust gas introduced into the pipe 84 and increasing the opening of the solenoid valve 83. Conversely, by increasing the opening of the solenoid valve 82, the amount of exhaust gas introduced into the second sub heat exchanger 9 is increased, and by decreasing the opening of the solenoid valve 83, the pipe 84 The amount of exhaust gas introduced can be reduced. The controller 80 controls the opening and closing of the solenoid valves 82 and 83,
The calorific value of the exhaust gas introduced into the device can be adjusted.

The exhaust temperature sensor 76 is connected to the controller 8
When a temperature higher than the temperature set at 0 is detected, the degree of opening and closing of the solenoid valves 82 and 83 is controlled, and the calorific value of the exhaust gas introduced into the second sub heat exchanger 9 is adjusted. In the second sub heat exchanger 9, since the heat is absorbed by the refrigerant, the temperature decreases due to a decrease in the amount of exhaust gas introduced. When the detected temperature of the exhaust gas temperature sensor 76 becomes lower than the set temperature, the degree of opening and closing of the solenoid valves 82 and 83 is controlled, and the calorific value of the exhaust gas introduced into the second sub heat exchanger 9 increases. I do. Thereby, the temperature of the second sub heat exchanger 9 is controlled, and the refrigerant can be used stably.

As shown in FIG. 12, it is also possible to arrange a valve arm 91 instead of the solenoid valves 82 and 83 to adjust the amount of exhaust gas flowing into the exhaust pipe 71 and the pipe 84. The valve arm 91 is provided downstream of the connection between the exhaust pipe 71 and the pipe 84. The valve arm 91 is disposed inside the exhaust pipe 71, and is configured to be rotatable integrally with a pulley 94 disposed outside the exhaust pipe 71. Pulley 94 has
One ends of the wires 92 are connected, and the other ends of the wires 92 are connected to a drive pulley of a servomotor 93. Therefore, the valve arm 91 is rotated by driving the servo motor 93. The servo motor 93 is connected to the controller 80, and its rotation is controlled by the temperature detected by the exhaust gas temperature sensor 76. When the detected temperature of the exhaust gas temperature sensor 76 is lower than the set temperature, as shown in FIG. Supply exhaust gas. When the temperature detected by the exhaust gas temperature sensor 76 is higher than the set temperature, as shown in FIG. 12B, the valve arm 91 suppresses the flow of exhaust gas into the second sub heat exchanger 9, and The exhaust gas is supplied to 84. Thus, the temperature of the second sub heat exchanger 9 is controlled.

[0047]

As described in the first aspect, the temperature of the exhaust gas supplied to the heat exchanger is adjusted, so that the heat quantity can be stably supplied to the heat exchanger. Further, the refrigerant introduced into the heat exchanger can be used stably.

Since the ignition timing of the engine is controlled by the temperature of the exhaust gas as described in the second aspect, the present invention can be implemented with a simple structure and the control mechanism hardly causes an error. The amount of heat supplied to the heat exchanger can be stabilized. Further, the refrigerant introduced into the heat exchanger can be protected.

Since the air-fuel ratio of the engine is adjusted according to the temperature of the exhaust gas, the amount of heat can be stably supplied to the heat exchanger. Further, the refrigerant introduced into the heat exchanger can be used stably.
Further, generation of nitrogen oxides can be suppressed, and durability of equipment exposed to exhaust gas can be improved.

Since the EGR valve is controlled by the temperature of the exhaust gas, the amount of heat supplied to the heat exchanger can be stabilized. Further, the refrigerant introduced into the heat exchanger can be protected. Further, generation of nitrogen oxides can be suppressed, and durability of equipment exposed to exhaust gas can be improved.

As described in the fifth aspect, the path of the exhaust gas connected to the heat exchanger is changed depending on the temperature of the exhaust gas, so that the amount of heat supplied to the heat exchanger can be stabilized. Further, the refrigerant introduced into the heat exchanger can be protected.

[Brief description of the drawings]

FIG. 1 is an exhaust heat recovery circuit diagram showing a basic configuration of utilizing exhaust heat of an engine.

FIG. 2 is a diagram showing a configuration of an exhaust gas heat exchanger and a second sub heat exchanger.

FIG. 3 is a diagram showing a configuration of a second sub heat exchanger.

FIG. 4 is a diagram showing a first embodiment of a refrigerant circuit and an exhaust heat recovery circuit.

FIG. 5 is a diagram showing a refrigerant circuit and a cooling water circuit of the first embodiment.

FIG. 6 is a diagram showing a second embodiment of a refrigerant circuit and an exhaust heat recovery circuit.

FIG. 7 is a diagram showing a third embodiment of a refrigerant circuit and an exhaust heat recovery circuit.

FIG. 8 is a diagram showing a fourth embodiment of a refrigerant circuit and an exhaust heat recovery circuit.

FIG. 9 is a diagram showing a connection configuration of a controller.

FIG. 10 is a diagram showing a control configuration of an exhaust gas temperature.

FIG. 11 is a diagram showing a configuration in which a bypass pipe is connected to an exhaust pipe.

FIG. 12 is a diagram showing a configuration of adjusting an exhaust gas flow rate to a bypass pipe.

[Explanation of symbols]

 3 Engine 7 Compressor 9 Second Sub Heat Exchanger 22 Outdoor Heat Exchanger 23 Indoor Heat Exchanger 25 First Sub Heat Exchanger 51 Exhaust Gas Heat Exchanger 71 Exhaust Pipe 72 Spark Plug 73 Throttle Valve 74 Fuel Supply Device 75 Air Cleaner 76 Exhaust temperature sensor 77 Solenoid valve 80 Controller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F25B 27/02 F02P 5/15 B

Claims (5)

[Claims] 1. A method for controlling an engine heat pump, comprising adjusting the temperature of exhaust gas supplied to a heat exchanger. 2. A control method for an engine heat pump, wherein the ignition timing of the engine is controlled based on the temperature of the exhaust gas. 3. A method for controlling an engine heat pump, comprising adjusting an air-fuel ratio of an engine according to a temperature of exhaust gas. 4. A method for controlling an engine heat pump, comprising controlling an EGR valve according to a temperature of exhaust gas. 5. A control method for an engine heat pump, wherein a route of an exhaust gas connected to a heat exchanger is changed according to a temperature of the exhaust gas.