JPS6086355A - Engine driving heat pump device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses an engine to drive a compressor, performs heat pump operation, and uses the obtained heat for cooling, heating, or hot water supply, as well as effectively utilizing engine exhaust heat. Regarding engine-driven heat pump devices that also aim to achieve A conventional example of this type of heat pump device is shown in FIG. 1 of the accompanying drawings. FIG. 1 shows the operating state of the heat pump during heating, and shows the prime mover 11. Compressor 12. Four-way valve 13. Water heat exchanger (condenser) 14. Check valve 16. expansion valve 16, and air heat exchanger (evaporator) 17. fan 1
It is composed of 9.

Further, FIG. 2 shows a heat pump cycle abcdefg drawn on a Mollier diagram of a refrigerant.

The vertical axis is the pressure of the refrigerant, and the horizontal axis is the enthalpy of the refrigerant.

To explain the heat pump cycle by comparing FIG. 1 and FIG. 2, the pressure P caused by the compressor 12.

The compression process from P2 to P2 is shown as q→a,
The condensation process in step 4 is from a to d, and hot water for heating is produced here. Furthermore, the throttling expansion process by the expansion valve 16 is indicated by d −+ 6, and the evaporation process by the air heat exchanger 17 is indicated by 8−+ q, where heat is pumped up from the atmospheric heat source.

Now, to explain in more detail the evaporation process in the air heat exchanger 17 for about 3 pages, the e − + f process is a process in which the refrigerant evaporates under an isothermal and 2-equal pressure, and the f → q process is This is a process in which evaporated refrigerant is superheated under equal pressure and its temperature rises. Here, the temperature difference between point f and point 9 is the degree of superheating, and the heat pump cycle is generally operated at a degree of superheating of about 6K to 10K. This is to prevent liquid compression, since if the liquid refrigerant flows into the compressor 12, the compressor 12 will compress the liquid and be damaged. Point 9 in FIG. 2 is indicated by the outlet 18 of the air heat exchanger 17 in FIG. The opening degree of the valve 16 is adjusted. Generally, such an expansion valve 16 is called a temperature expansion valve. For example, when the atmospheric temperature decreases and the degree of superheating becomes small, the expansion valve opening degree is decreased to reduce the pressure drop due to the expansion valve. It plays the role of increasing the evaporation pressure P1 and lowering the evaporation pressure P1 to ensure an appropriate degree of superheating.

By the way, when comparing the evaporation process e→f and the superheating process f-+g, in the evaporation process 111-J) f, heat transfer is accompanied by a phase change of the refrigerant, whereas in the superheating process f→q, the refrigerant changes. Since it is a single-phase (gas) heat transfer, the local heat transfer coefficient is significantly lower in the latter than in the former. Although the heat transfer amount in the superheating process f-+g is only about the same as the heat transfer amount in the evaporation process 6-+f, the heat transfer area is
In some cases, the μ of the entire evaporator is also used for 'g.

As mentioned above, in conventional evaporators, all the heat transfer surfaces are not often used effectively for heat transfer accompanied by a phase change of the refrigerant, and a considerable amount of heat transfer is required due to the overheating of the refrigerant in its gaseous state. Since the heat transfer surface is used, there is a problem in that the heat transfer efficiency per heat transfer area of the evaporator as a whole is low.

Also, when using an engine as the drive source for the compressor,
Countermeasures have been taken to reduce noise by housing the engine and compressor in the same housing and sealing them, but if the engine and compressor are housed in the same housing and hermetically sealing them, the heat radiated from the engine and compressor will reduce the noise. The air temperature inside the body is 100″
It goes up to about C and ends up being 6 pages long. As a result, the temperature of the intake air to the engine increases, the amount of intake air decreases, and the engine output decreases.
There has been a problem in that the temperature of the compressor increases, resulting in a decrease in compression efficiency and, ultimately, a decrease in the coefficient of performance.

OBJECT OF THE INVENTION The present invention solves the above-mentioned drawbacks of the conventional technology.
Another object is to provide an engine-driven heat pump device with a small heat exchanger.

Composition of the Invention In order to achieve the above object, the engine-driven heat pump device according to the present invention has a compressor installed in a housing housing the engine and the compressor so that the refrigerant at the outlet of the evaporator is in a gas-liquid mixed state. and a means for heating the refrigerant sucked into the housing by the air within the housing.Description of an Embodiment An embodiment of an engine-driven heat pump device according to the present invention is shown in FIG. Reference numeral 21 is an engine, and reference numeral 22 is a compressor driven by the engine 21.

The gaseous refrigerant compressed to high pressure by the compressor 22 is
It is fed into the four-way valve 23. This four-way valve 23 reverses the flow direction of the refrigerant during cooling operation and during heating operation, and FIG. 3 shows the position of the four-way valve during heating operation. In addition, the solid arrow in Figure 3 indicates the heat medium (
The dotted line arrow indicates the flow direction of the heat medium during cooling operation.

In the following, the present invention will be explained by taking a heating operation along the solid arrow as an example.

The gaseous refrigerant that exits the four-way valve 23 is condensed in a water heat exchanger 24 (condenser during heating operation, evaporator during cooling operation),
At this time, hot water for heating is created using the latent heat of condensation of the refrigerant. The liquid refrigerant leaving the water heat exchanger 24 passes through the check valve 26 and then through the expansion valve 26 and is depressurized. After this, the low-pressure liquid refrigerant is transferred to an air heat exchanger equipped with a fan 29 (an evaporator during heating operation,
During cooling operation, heat is taken from the atmospheric heat source in the condenser (27) and steam is generated. At this time, the temperature signal at the outlet 28 of the air heat exchanger 27 is fed to the expansion valve 26 along the dashed line 26', and the expansion valve 26 detects that the refrigerant at the outlet 28 of the air heat exchanger 27 is mixed with gas and liquid. Adjust the opening degree so that the two-phase state is achieved.

That is, only evaporation of the refrigerant occurs in the air heat exchanger 27, and the gaseous refrigerant is not superheated.

Then, the refrigerant in the gas-liquid mixed state passes through the four-way valve 23 again, and then enters the heat exchanger 31 provided in the casing 3o that houses the engine 21 and compressor 22.

Here, the remaining liquid refrigerant is heated by the high temperature air inside the housing 3o, completely evaporates, and is further superheated to the compressor 2.
Returning to step 2, the heat pump cycle is completed.

Further, 32 is a heat exchanger for recovering exhaust heat from engine exhaust gas, and also serves as a muffler.

33 is a hot water next circuit, which includes a water heat exchanger (condenser) 2
4, the further heated water flows through the water jacket disposed around the engine 21 and through the exhaust heat recovery heat exchanger 32. 34 is a hot water heat exchanger, and 36 is a hot water secondary circuit. The hot water heat exchanger 34 plays the role of transmitting the heat of the hot water secondary circuit 33 to the secondary circuit 36, thereby warming the water in the hot water storage tank 36. Further, 37 is a water supply flow path, and 38 is a hot water extraction flow path.

Now, according to the present invention, since the refrigerant evaporates with a phase change in the air heat exchanger (evaporator) 27 from the inlet to the outlet, the local heat transfer coefficient also changes near the outlet. It can be maintained higher than before. That is, when evaporating at the same evaporation pressure as in the past, the air heat exchanger 27 can be made smaller by the amount used in the conventional superheating process. On the other hand, when the same air heat exchanger 27 as the conventional one is used, the temperature difference with the atmospheric heat source can be reduced by the improvement in the local heat transfer coefficient near the outlet, so the evaporation pressure increases. The difference between the evaporation pressure and the condensation pressure of the heat pump cycle is reduced, and the coefficient of performance of the heat pump cycle is improved.

That is, according to the present invention, the entire heat transfer area of the evaporator can be effectively utilized.

However, in order to realize the above advantages, the engine 21
In addition, a heat exchanger 31 that heats the refrigerant using the air in the housing 30 must be newly installed in the housing 3o that houses the compressor 22. Here, since the casing 30 has a sealed structure to shield noise from the engine 21 and compressor 22, the inside of the casing 3o is several tens of degrees warmer than the atmospheric heat source due to the heat radiated from the engine 21 and compressor 22. Become. Therefore, a heat exchanger 31 for heating the refrigerant is installed inside the housing 30.
The present invention is still highly effective even if it is newly provided.

In addition, conventionally, the inside of the housing 3o reached a high temperature of 100'C.
As the temperature rises to a certain degree, the temperature of the air taken into the engine 21 also rises, and the intake air amount (mass) decreases.
There has been a problem that the engine output decreases and that the compressor 22 itself becomes high temperature and the compression efficiency (and thus the coefficient of performance of the heat pump) decreases, but according to the present invention, the engine 21 and the compressor 22 Heat radiation is done by compressor 1
Since it is used to heat the refrigerant sucked into page 22, the case 3o
The internal temperature rise is reduced, and the above-mentioned conventional problems are also solved.

Effect of the invention According to the present invention, the following effects are brought about.

(1) Since the heat transfer surface within the evaporator can be effectively utilized, it is possible to provide an engine-driven heat pump device with a small evaporator or a heat pump cycle with a high coefficient of performance.

(2) It is possible to suppress the temperature rise inside the casing housing the engine and compressor, thereby minimizing the decrease in engine output and compressor efficiency, making it possible to provide an engine-driven heat pump device with a high coefficient of performance. .

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram showing a conventional heat pump device, Fig. 2 is a diagram showing a heat pump cycle on a Mollier diagram of a refrigerant, and Fig. 3 is a schematic diagram showing an embodiment of an engine-driven heat pump device according to the present invention. It is a page schematic structure diagram. 11.21...Engine, 12.22...
...Compressor, 13.23...Four-way valve, 14.2
4... Water heat exchanger (condenser), 15.25...
...Check valve, 16゜26...Expansion valve, 17
．． 27... Air heat exchanger (evaporator), 18.2
8... Evaporator outlet, 3o... Housing, 3
1... Heat exchanger for heating refrigerant, 32...
Exhaust heat recovery heat exchanger, 33...Hot water - next circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] A compressor driven by the engine and a condenser (evaporator)
The refrigerant circuit includes an evaporator (condenser), an expansion valve, etc.; An engine-driven heat pump, characterized in that the engine-driven heat pump is provided with an adjustment means, and includes means for heating refrigerant exiting the evaporator and being sucked into the compressor by air inside the housing, in a housing housing the engine and the compressor. Device.