JPS58160774A - Hot-water supply 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 The present invention relates to a hot water supply device using solar heat and atmospheric heat using a heat pump.

2. Description of the Related Art Conventionally, solar water heaters that use water as a heat collecting medium are generally known as water heaters that utilize solar heat. In these conventional solar water heaters that use water as a heat collection medium, the amount and temperature of heat collection is naturally influenced by solar radiation, and the water heater requires an auxiliary heat source. In addition, since heat collectors efficiently collect dilute solar heat, the heat collection area becomes large, and since they are made of transparent glass and heat insulating materials, they become heavy, and additional installation materials are required to install the heat collector. There were drawbacks such as:

A possible solution to these conventional drawbacks is to use a heat pump in a solar heat collector. That is,
As shown in Fig. 1, there are a compressor 1', a condenser 2', and an expansion valve 3.
', a refrigerant heat collection circuit formed by sequentially connecting a heat collector 4' in a ring, and a water heating circuit formed by sequentially connecting a hot water storage tank 6', a water circulation pump 6', and a water heater 7' in a ring. Condenser 2
' and the water heater 7' are held in a heat transfer relationship to constitute a water heater. Incidentally, the heat collector 4' is constituted by a fin-chip heat exchanger.

To explain the operation of the water heater described above, when the compressor 1' operates, the discharged refrigerant gas compressed to high temperature and high pressure flows into the condenser 2', and has a heat transfer relationship with the condenser 2'. Heat is radiated through the water heater 7' to the flowing hot water, causing it to condense and liquefy. Next, the pressure is reduced by the expansion valve 3', the temperature and pressure become low, and the refrigerant flows into the heat collector 4' where it evaporates.If the evaporation temperature in the heat collector 4' is set lower than the outside air temperature, the refrigerant absorbs more heat than solar heat and atmospheric heat. , evaporate and gasify, and return to the compressor 1'. - The hot water heated by the latent heat of condensation of the refrigerant while flowing through the power water heater 7' is circulated through the water heater 7' and the hot water storage tank 6' by the action of the water circulation pump 6' and is raised in temperature.

As described above, most of the solar heat, atmospheric heat absorbed by the heat collector 4', and compression work heat consumed by the compressor is radiated by the water heater 7', which is in a heat transfer relationship with the condenser 2', to supply hot water. It heats water. Therefore, in a water heater that uses a heat pump as a solar heat collection means, heat collection operation is possible even when there is no solar radiation, so a small heat collection area is required. It becomes possible to increase the amount of heat collected. Further, the heat collector 4' is composed of a fin-cheve heat exchanger or the like, which has advantages such as a light and compact lid and extremely easy installation work.

However, a problem when the heat pump is applied to a solar heat collector is that the load on the heat collector 4' varies widely, resulting in frequent quenching of the expansion valve 3'. That is, the evaporation capacity of the heat collector 4' is influenced by solar radiation, outside air wind speed, outside temperature and humidity, etc. Therefore, it is necessary for the expansion valve 3' to instantaneously control the refrigerant amount to follow wide range fluctuations in capacity. - The problems associated with the nitching phenomenon include the inability to use the capacity of the heat collector 4' effectively, liquid returning to the compressor, and a decrease in compressor reliability due to load fluctuations of the compressor motor. be.

As described above, the present invention aims to improve heat collection efficiency and compressor reliability by preventing the expansion valve from shrinking due to load fluctuations in a water heater that uses a heat pump as a solar heat collector. This is the purpose.

In order to achieve the above object, the present invention is characterized by:
Compressor, condenser, expansion valve, and heat collector in sequence ・1
It is equipped with a refrigerant heat collection circuit connected in a ring, and a water heating circuit in which a hot water storage tank, a water circulation pump, and a water heater are connected in order in a ring, and the condenser and water heater are maintained in a heat transfer relationship. In the water heater, a liquid-gas heat exchanger is provided for exchanging heat between the refrigerant liquid between the condenser and the expansion valve of the refrigerant heat collection circuit and the evaporated low-temperature refrigerant gas exiting the heat collector; The temperature-sensitive cylinder of the valve is fixed to the low-temperature gas pipe at the outlet of the liquid-gas heat exchanger.

According to the present invention, when the refrigerant condition at the collector outlet suddenly changes due to a change in the collector load, that is, a sudden change in the amount of solar radiation or a sudden change in the outside air wind speed, and unevaporated refrigerant is included. In this case, by heat exchange with the high temperature liquid refrigerant, the unevaporated refrigerant is completely gasified and has an appropriate degree of superheating, and is sucked into the compressor.

In other words, conventionally, when unevaporated refrigerant enters the outlet of the collector, the wet part of the expansion valve tube fixed to the compressor length inlet pipe detects this and closes the expansion valve, causing a sudden drop in low pressure, which causes the compressor motor to This is effective in preventing hunting phenomena such as sudden changes in the load on the vehicle. Therefore, due to the hunting phenomenon, the heat collection ability decreases, unevaporated refrigerant is inhaled,
This makes it possible to prevent a decrease in compressor reliability due to sudden changes in motor load, etc.

The present invention will be explained in detail below. In Fig. 2, 1 is a compressor, 2 is a condenser, 3 is an external pressure equalization type expansion valve body, and 4 is a heat collector, which is composed of a fin-chive heat exchanger and whose surface is painted black. .

8 is a gas-liquid separator, and 12 is another gas-liquid separator directly connected to the suction pipe of the compressor 1. Reference numeral 9 denotes a liquid-gas heat exchanger, which is composed of double pipes, in which a liquid refrigerant after condensing flows through an inner pipe 9a and a low-pressure gaseous refrigerant flows through an outer pipe 9b.

Reference numeral 10 denotes a temperature-sensitive cylinder of the expansion valve 3, which is fixed to the outlet low-pressure gas pipe of the liquid-gas heat exchanger 9.

The refrigerant is transferred from the compressor 1 to the condenser 2 to the liquid gas heat exchanger 9 to the expansion valve 3 to the connecting pipe 11a to the heat collector 4 to the connecting pipe 11b to the gas-liquid separator 8 to the liquid-gas heat exchanger 9 to gas-liquid separation. Container 8 ~ Compressor 1
The refrigerant is connected to circulate in this order to form a refrigerant heat collection circuit.

6 is a hot water tank, 6 is a water circulation pump, and 6 is a water heater.
These are sequentially connected in a ring to form a water heating circuit.

The condenser 2 of the refrigerant heat collection circuit and the water heater 7 of the water heating circuit
is held in a heat transfer relationship. For example, it consists of a double tube heat exchanger.

Next, the operation of the water heater with the above configuration will be explained.

The high-temperature, high-pressure discharged gas refrigerant compressed by the compressor 1 flows into the condenser 2 . Here, the water heater 7, which is in a heat transfer relationship with the condenser 2, radiates heat to the flowing hot water by the action of the water circulation pump 6, and condenses and liquefies it. The liquid refrigerant that has flowed out of the condenser 2 radiates heat to the low-temperature evaporative refrigerant in the liquid-gas heat exchanger 9, and is further subcooled.The liquid refrigerant is depressurized by the expansion valve 3 to become low temperature and low pressure, and then passes through the connecting pipe 11a. , flows into the heat collector 4, and evaporates at a temperature slightly lower than the outside air temperature. Hence solar heat.

It absorbs heat from the atmosphere, becomes evaporative gas, and passes through the connecting pipe 11b.
The gas is completely evaporated and gasified while passing through the gas-liquid separator 8 and the liquid-gas heat exchanger 9, and then flows into the compressor 1 in a superheated gas state having a predetermined degree of superheat. The hot water heated by the water heater 7 is sequentially stored in the hot water storage tank 6.

Next, the action of the heat collector 4 when the load fluctuates will be explained.

In other words, if the solar radiation suddenly decreases or the outside air wind speed decreases, the amount of heat collected by the heat collector 4 decreases, and the heat loss necessary for the refrigerant flowing through the heat collector 4 to evaporate cannot be obtained. Unevaporated refrigerant enters the outlet of the collector 4. Then, the unevaporated refrigerant flows through the connecting pipe 11b and flows into the gas-liquid separator 8, where it is separated into gas refrigerant and liquid refrigerant, and the saturated gas refrigerant is transferred from the gas-liquid separator 7 to the liquid-gas heat exchanger. 9
Here, the refrigerant absorbs heat from the condensed liquid refrigerant, attains a predetermined degree of superheat, and flows into the compressor 1.

As explained above, according to the embodiment of the present invention, the amount of solar radiation to the collector 4 and the wind speed of outside air decrease, and the collector capacity decreases, so that unevaporated refrigerant mixes at the outlet of the collector 4. A predetermined degree of superheating is obtained by separating the refrigerant into liquid and gas in the gas-liquid separator 8, and introducing the saturated gas refrigerant into a liquid-gas heat exchanger to absorb heat from the condensed refrigerant. Therefore, even if unevaporated refrigerant gets mixed into the collector outlet due to a sudden change in the collector load, the expansion valve will not close suddenly, and the heat collection capacity will decrease. In addition to liquid return, sudden load fluctuations of the compressor motor can be prevented and compressor reliability can be improved.

As explained above, the present invention relates to a hot water supply system using a heat pump as a solar heat collecting device, and a compressor.

A liquid-gas heat exchanger is provided for exchanging heat between the liquid refrigerant between the condenser and the expansion valve of a refrigerant heat collection circuit in which a condenser, an expansion valve, and a heat collector are sequentially connected in a ring, and a return gas refrigerant from the heat collector, By fixing the temperature-sensitive tube of the expansion valve to the suction gas pipe at the outlet of the liquid gas heat exchanger, if the collector capacity decreases due to a decrease in solar radiation or outside air wind speed, unevaporated refrigerant will not flow to the collector outlet. Even if contamination occurs, heat is absorbed from the condensed liquid refrigerant in the liquid-gas heat exchanger, and the unevaporated refrigerant can be completely gasified. Therefore, liquid return when the collector load decreases,
It becomes possible to prevent a decrease in evaporation pressure, that is, a hunting phenomenon due to the rapid closing operation of the expansion valve accompanying this. This prevents the heat collection ability from decreasing and increases the heat collection efficiency.

In addition, liquid return can prevent load fluctuations on the compressor motor due to sudden pressure fluctuations, and can improve the reliability of the compressor.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a water heater when a heat pump is used as a solar heat collector, and FIG. 2 is a circuit diagram of the water heater of the present invention. 1...Compressor, 2...-Condenser, 3...
...Expansion valve, 4... Heat collector, 5...
・Hot water tank, 6...Water circulation pump, 7...
・Water heater, 8... Gas-liquid separator, 9...
・Liquid gas heat exchanger, 10... Temperature sensing cylinder, 11...
...Connection piping.

Claims (1)

[Claims] A refrigerant heat collection circuit in which a compressor, a condenser, an expansion valve, and a heat collector are sequentially connected in a ring, and a water heating circuit in which a hot water storage tank, a water circulation pump, and a water heater are sequentially connected in a ring, and a condenser in the refrigerant heat collection circuit. and a water heater in the water heating circuit in a heat transfer relationship, and a liquid-gas heat exchange section for exchanging heat between the high-temperature liquid refrigerant between the condenser and the expansion valve and the low-temperature gaseous refrigerant exiting the collector; A water heater in which a temperature-sensitive cylinder of an expansion valve is fixed to an outlet low-temperature gas pipe of the liquid-gas heat exchanger.