JPS6162766A - Engine-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 relates to an engine heat pump device that is capable of improving performance by ensuring an appropriate degree of subcooling of a liquid refrigerant in a refrigerant circulation cycle.

[Prior Art] In general, an engine-driven heat pump device can recover exhaust heat from engine exhaust gas or heat from water cooling using an exhaust gas heat exchanger or a cooling water heat exchanger. ) It has better energy usage efficiency than J heat pump equipment, and is used as various hot water supply equipment. This type of engine heat pump device is
For example, as shown in FIG. 2, the engine 1 causes the compressor 2 to
is OJed, and the refrigerant forms a circulation path through the compressor 2 → water-cooled condenser 3 → expansion valve 4 → evaporator 5 and returns to compression example 2 again. The high-pressure refrigerant gas compressed by the compressor 2 is condensed by exchanging heat with water in the water-cooled condenser 3, then adiabatically expanded in the expansion valve 4, and evaporated in the evaporator 5 to pump up heat from the low heat source. The cycle returns to compression tJl 2 again. Also, a water-cooled condenser 3, an expansion valve 4, and an evaporator 5
A heat interchanger 6 is provided in the refrigerant circulation path of the compressor 2, which cools the liquid refrigerant discharged from the condenser 3 with the low-temperature gas refrigerant from the evaporator 5, and generates flash gas before the expansion valve 4. The aim was to suppress generation and obtain an appropriate degree of supercooling to maintain the liquid refrigerant. In addition, a cooling water heat exchanger 7 iJ is installed in the cooling water circulation path and exhaust gas path of the engine 1.
3 and an exhaust gas heat exchange n8 are provided, and the hot water (brine) is transferred by a pump 9 from the water-cooled condenser 3 to the cooling water heat exchanger 7 to the exhaust gas heat exchanger 8 to the pump 9 again via a buffer tank (not shown). It forms the return hot water circuit.

The hot water is then used as a heat source for a hot water supply facility (not shown) or the like. The exhaust gas that has passed through the exhaust gas heat exchanger 8 is discharged to the outside through a muffler 10.

[Problems to be Solved by the Invention] However, in such a conventional engine heat pump device R, when the temperature of the intake air in the evaporator 5 increases, the low pressure refrigerant gas 'fA degree increases, The temperature of the refrigerant gas discharged from the compressor 2 was increased. In addition, when the temperature of the hot water in the hot water circuit is low and the temperature of the high-pressure refrigerant liquid coming out of the condenser 3 is low, the temperature difference between the two refrigerants entering the heat interchanger 6 disappears, and an appropriate surcharge corresponding to the evaporation temperature of the refrigerant is generated. There were times when the cooling degree could not be adjusted to 14. Therefore,
The hot water supply capacity may decrease due to insufficient heat absorption in the evaporator 5,
Alternatively, there is a problem in that the compressor 2 is unable to compress the liquid.

Furthermore, Japanese Patent Application Laid-Open No. 58-49875 discloses a conventional technology related to a compression heat pump in which a second condenser is provided in the refrigerant cycle and the refrigerant is secondarily condensed by a blower fan to ensure the degree of supercooling. However, this conventional technique requires a blower fan and sometimes releases heat to the outside in a second condenser.

The present invention has been made by focusing on such conventional problems, and has made it possible to ensure an appropriate degree of supercooling of the refrigerant, suppress the generation of flash gas, etc., and improve the performance as a heat pump. The purpose is to provide engine heat pump equipment.

[Means for Solving the Problems] In order to solve the above problems, the engine heat pump device of the present invention uses engine-driven compression.

In a heat pump device consisting of a refrigerant circuit in which a water-cooled condenser, an expansion valve, and an evaporator are sequentially connected, and a hot water circuit that flows through the water-cooled condenser, there is a A heat interchanger for mutually exchanging heat is provided in the refrigerant circulation path between the pipes, and a bypass pipe is provided in the hot water circuit to bypass the water-cooled condenser via a flow rate adjustment section. A detector is installed for detecting the inflow temperature of the high-pressure refrigerant liquid and the inflow temperature of the low-pressure refrigerant gas.
°4 has been completed.

[Operation] Next, the operation will be explained. When the intake air temperature of the evaporator increases and the evaporation temperature of the refrigerant increases, or when the hot water temperature decreases and the condensation temperature of the refrigerant in the condenser decreases, the temperature of the refrigerant liquid flowing into the heat interchanger and the refrigerant decrease. The temperature difference between the gas inflow temperatures is detected by sensing bodies provided in the respective pipes. Then, when this temperature difference becomes smaller than a set value, the flow m adjusting section is operated differentially, and the flow is adjusted so as to reduce the water inflow into the water-cooled condenser. For this reason, the number of heat exchanges in the water-cooled condenser is reduced, increasing the condensation temperature of the refrigerant, and controlling the temperature so that the high-pressure liquid refrigerant temperature is higher than the low-pressure gas refrigerant temperature, ensuring a degree of subcooling that matches the low-pressure gas refrigerant temperature. be done. Therefore, generation of flash gas can be prevented, and the hot water supply capacity of the heat pump can be improved.

[Examples] Examples according to the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a system diagram of an engine heat pump device according to an embodiment of the present invention.

In this figure, reference numeral 11 is an engine, and 12 is a compressor driven by the engine 11. The refrigerant circulation path of this engine heat pump device is configured to circulate from the high-pressure side of the compressor 12 to the low-pressure side of the compressor 12 via the water-cooled condenser 13 → expansion valve 14 → evaporator 15.

Further, the refrigerant outlet side of the water-cooled condenser 13 and the expansion valve 14
A heat interchanger 16 is provided in the refrigerant circulation path between the refrigerant inlet side of the evaporator 15 and the refrigerant inlet side of the compressor 12, and in the refrigerant circulation path between the refrigerant outlet side of the evaporator 15 and the refrigerant suction side of the compressor 12. It is provided.

A cooling water heat exchanger 17 is connected to the cooling water circulation path of the engine 11 to recover heat generated by water cooling of the engine. Further, an exhaust gas heat exchanger 18 is provided in the exhaust gas path of the engine 11. At step 1, the exhaust gas is discharged from the exhaust gas heat exchanger 18 to the outside via the muffler 19. In addition, a pump 20 is connected to the hot water inlet side (brine inlet side) of the water-cooled condenser 13.
It is connected to a buffer tank (not shown) through
The hot water circuit during normal operation forms a circulation path from the buffer tank through the pump 20, the water-cooled condenser 13, the cooling water heat exchanger 17, the exhaust gas heat exchanger 18, and then back to the buffer tank.

On the other hand, the hot water pipe 21 on the hot water inlet side of the water-cooled condenser 13
A bypass pipe 22 is provided which branches from the hot water pipe 21, and the outlet side of the bypass pipe 22 is connected to a hot water pipe 23 on the hot water outlet side of the water-cooled condenser 13. A flow rate adjustment section 24 is provided at a connecting portion between the bypass pipe line 22 and the hot water pipe line 23. The flow m adjustment section 24 has a structure that can adjust the ratio of hot water flowing into the water-cooled condenser 13 and the bypass pipe line 22. Furthermore, in the high-pressure refrigerant liquid inlet pipe 25 and low-pressure refrigerant gas inlet pipe 26 portions of the heat interchanger 16, there are sensing bodies 27 for detecting the temperature of the refrigerant flowing therein.
28 are provided.

The detection bodies 27 and 28 are connected to a temperature difference thermometer 29 that calculates and detects the temperature difference between them. This temperature difference thermostat 29 is connected to a control device 30 that controls the flow m adjustment section 24 . This control device 30 operates the flow m adjustment unit 24 to reduce the hot water flow M flowing to the water-cooled condenser 13 when the value of the humidity difference by the temperature difference thermometer 29 becomes smaller than the set value, so that the hot water flows into the bypass pipe 22. It is designed to control the flow.

In such a configuration, the engine 11 runs and the compressor 12 is driven to circulate refrigerant, and the pump 20 circulates hot water (brine).

Then, the temperature difference between the temperatures detected by the detection bodies 27 and 28 provided at the high-pressure refrigerant liquid inlet side pipe line 25 and the low-pressure refrigerant gas inlet side pipe line 26 portion of the heat interchanger 16 is calculated and detected by the temperature difference thermometer 29. Ru. When this detected temperature difference becomes smaller than the set value, when the intake air temperature at J5 to the evaporator 15 is high and the inlet brine temperature of the water-cooled condenser is low, the control 2II device 30 will The adjustment unit 24 is activated to reduce the hot water flow m flowing into the water-cooled condenser 13. Therefore, heat exchange between hot water and refrigerant in the water-cooled condenser 13 is reduced, increasing the condensation temperature of the refrigerant. Therefore, the temperature of the high-pressure liquid refrigerant can be controlled so that the temperature of the low-pressure gas refrigerant is greater than the temperature of the low-pressure gas refrigerant, ensuring a degree of subcooling that matches the temperature of the low-pressure gas refrigerant, preventing the generation of flash gas, and improving the hot water supply capacity as a heat pump. be able to.

In the above embodiments, the flow rate adjustment section 24 may have any structure as long as it can reduce the color of the hot water flowing into the water-cooled condenser 13, and may be provided at a branch portion on the inlet side of the bypass pipe 22. . Further, the hot water circuit may include the water-cooled condenser 13 in its configuration, and is not limited to the system of the embodiment. Furthermore, the flow m adjustment section 24 may be manually operated based on the temperature difference caused by the detection bodies 27 and 28.

[Effects of the Invention 1] As explained above, according to the present invention, a bypass pipe is provided that bypasses the water-cooled condenser in the drought circuit via the flow rate adjustment section, and the high-pressure liquid refrigerant inlet temperature of the heat interchanger in the refrigerant circulation path is adjusted. The system detects the difference in the low-pressure gas refrigerant inlet temperature, and when the temperature difference becomes smaller than the set value, the flow control device is activated to reduce the flow rate of water flowing into the water-cooled condenser. This has the effect of being able to control the condensation temperature of the refrigerant, ensuring an appropriate degree of subcooling of the refrigerant, suppressing the generation of flash gas, and improving the performance of the heat pump.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an engine heat pump device according to an embodiment of the present invention, and FIG. 2 is a system diagram of an engine heat pump device according to a conventional example.
It is a system diagram of a heat pump device. 11...Engine 12...Compressor 13...Water-cooled condenser 14
... Expansion valve 15 ... Evaporator 16 ... Heat interchanger 22 ... Bypass pipe line 24 ... Stream adjustment section 25
...High pressure refrigerant liquid inlet side pipe 26...Low pressure refrigerant gas inlet side pipe 27.28...Detector 29...Differential temperature thermometer 30
...Control 21 + device Fig. 1 Fig. 2

Claims (1)

[Claims] A heat pump device comprising a refrigerant circuit in which a compressor driven by an engine, a water-cooled condenser, an expansion valve, and an evaporator are sequentially connected, and a brine circuit through which brine for exchanging heat with the refrigerant flows through the water-cooled condenser. A heat interchanger for mutual heat exchange is provided in the refrigerant circuit between the water-cooled condenser and the expansion valve through which the high-pressure refrigerant liquid flows, and between the evaporator and the compressor through which the low-pressure refrigerant gas flows, and a flow rate adjustment unit is provided in the brine circuit. A bypass pipe is provided to bypass the water-cooled condenser through the heat interchanger, and a temperature sensing body is provided in each of the high-pressure refrigerant liquid inlet pipe and the low-pressure refrigerant gas inlet pipe of the heat interchanger,
An engine heat pump device characterized in that the flow rate adjustment section is adjusted based on the temperature difference between the sensing bodies to control the condensation temperature of the refrigerant.