JPH0368316B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solar heat pump device that operates using solar heat as a heat source on sunny days and using outside air heat as a heat source when the weather is bad.

FIG. 1 is a circuit diagram of a hot water supply system showing a conventional solar heat pump device disclosed in, for example, Japanese Utility Model Application Publication No. 56-141972. 1, an expansion valve 3, a solenoid valve 4, and an evaporator 5 are provided on the outlet side of the condenser 2, and the outlet side of the evaporator 5 is connected to the compressor 1.
connected to the suction side of the Evaporator 5 is fan 6
It is equipped with

A series circuit of a solar collector 7 and a solenoid valve 8 is connected in parallel to a series circuit of an evaporator 5 and a solenoid valve 4. Note that 9 is a hot water storage tank into which the condenser 2 is inserted.

Now, there are four types of operating conditions for solar heat pump equipment: sufficient solar radiation, somewhat reduced solar radiation, intermediate solar radiation, and no solar radiation. The operation of the conventional solar heat pump device will be explained based on these operating conditions.

First, during the day when the weather is bad and the amount of solar radiation is low, or at night, when the amount of solar radiation is intermediate,
When there is no sunlight, an evaporator 5 and a fan 6 are used to draw heat from the outside air and heat the water in the hot water tank 2.

The solenoid valve 4 is kept open and the solenoid valve 8 is kept closed. The high-temperature, high-pressure refrigerant gas discharged from the compressor 1 gives heat to the water in the hot water storage tank 9 in the condenser 2 and is condensed and liquefied.

Next, the pressure is reduced by the expansion valve 3 to become a low-temperature, low-pressure liquid refrigerant, which enters the evaporator 5 through the solenoid valve 4.
By blowing air from the fan 6, the refrigerant receives heat from the outside air, boils and evaporates, and returns to the compressor 1 as a low-temperature, low-pressure gas refrigerant.

Water is also heated using solar heat as a heat source on sunny days, when there is sufficient solar radiation, or when solar radiation has decreased somewhat. At this time, solenoid valve 4
is closed, and solenoid valve 8 is opened. The liquid refrigerant that has passed through the expansion valve 3 is heated by solar heat in the solar collector 7, evaporates, and returns to the compressor 1.

The evaporation temperature is different when using outside air as a heat source and when using solar heat as a heat source, and when using outside air heat, the evaporation temperature is several degrees lower than the outside temperature, and when using solar heat, it depends on the formation of the solar heat collector 7. However, the temperature will be around the outside temperature or several to a dozen degrees above the outside temperature.

Therefore, when solar heat is used, the difference between the evaporation temperature and the condensation temperature is smaller, the electrical input to the compressor 1 consumed to obtain the same amount of heat is smaller, and the coefficient of product (COP) of the heat pump is lower. improved;
Energy-saving operation.

Since the conventional solar heat pump device is configured as described above, the capacity required of the compressor 1 differs greatly depending on whether the outside temperature is low or when there is high solar radiation. Even if the capacity was controlled by changing the capacity, there was a drawback that it was difficult to optimally control the capacity and COP under all operating conditions. for example,
Even if you try to operate the evaporator 5 and solar collector 7 together when the amount of solar radiation is intermediate,
This was practically impossible for reasons explained below.

Further, FIG. 2 is a circuit diagram of a hot water supply system showing still another conventional solar heat pump device shown in Japanese Patent Publication No. 57-60533, in which the compressor 1, condenser 2, evaporator 5, The fan 6 and hot water storage tank 9 are exactly the same as the conventional example shown in Fig. 1, and the main piping system includes a compressor 1, a condenser 2, an evaporator 5, and a check valve 12 arranged in this order on the discharge side. The outlet side of the valve 12 is connected to the suction side of the compressor 1.

In addition, a circuit branched from the middle of the condenser 2 and the evaporator 5 includes a pump 10, a solar collector 7, and a check valve 1.
1 to the suction side of the compressor 1.
The pump 10 is for conveying refrigerant liquid to the inlet side of the solar collector 7.

Note that 13 is a check valve provided in a circuit that bypasses the front and back of the compressor 1, and prevents gas from flowing back from the discharge side to the suction side of the compressor 1. Although not shown, an expansion valve 3 is provided between the condenser 2 and the evaporator 5.
is provided.

Next, the operation will be explained. First, when there is sufficient solar radiation, the solar heat collector 7 is heated by the solar radiation, and the liquid refrigerant evaporates, passes through the check valve 11 and reaches the compressor 1 due to high pressure.

At this time, if the gas pressure is high enough to liquefy the refrigerant in the condenser 2, the compressor 1 is stopped,
The gas passes through the check valve 13, reaches the condenser 2, is liquefied, and returns to the solar collector 7 again by the pump 10.

Next, when the solar radiation decreases somewhat, the compressor 1 is operated to evaporate the refrigerant in the solar collector 7 at a temperature lower than the temperature of the condenser 2. When there is no solar radiation, the pressure in the evaporator 5 is higher than the pressure in the solar collector 7, so the check valve 11 is closed and the check valve 12 is opened, operating as a normal air source heat pump. Note that the check valve 13 is closed while the compressor 1 is in operation.

Since the conventional second solar heat pump device is configured as described above, when there is sufficient solar radiation, only the pump 10 is used, and the refrigerant is distributed between the solar heat collector 7 and the condenser 2 at almost the same temperature and pressure like a heat pipe. The energy is circulated through the air, resulting in energy-saving operation.

In addition, when there is no solar radiation, the operation is similar to that of a conventional air source heat pump, but when the solar radiation is of intermediate intensity, the solar collector 7 is used as an evaporator, making it difficult to operate in combination with the evaporator 5. Become. In other words, since the solar collector 7 and the evaporator 5 are both located on the low pressure side of the refrigeration cycle,
Temperature and pressure become almost equal.

If the evaporation temperature is set higher than the outside temperature,
Heat is radiated from the evaporator 5 by natural convection, resulting in heat loss.If the evaporation temperature is set lower than the outside temperature, the difference between the evaporation temperature and the condensation temperature will increase, the COP will decrease, and the characteristics of a solar heat pump will be lost. It had the drawback of being called out.

This drawback also applies to the case where the evaporator 5 and the solar collector 7 are operated in combination in the first conventional example.

This invention was made to eliminate the above-mentioned conventional drawbacks, and by providing a refrigerant liquid conveying pump and a solar collector in parallel with the condenser,
The purpose of the present invention is to provide a solar heat pump device that can efficiently utilize both solar heat and outside air heat even when the amount of solar radiation is intermediate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the solar heat pump device of the present invention will be described below with reference to the drawings. FIG. 3 is a circuit diagram of the hot water supply system, and FIG. 4 is a Mollier diagram of the refrigeration cycle during hot water supply operation. The compressor 1, condenser 2, evaporator 5, and hot water storage tank 9 in FIG. are exactly the same.

The main piping system has a compressor 1 and a check valve 1 on its discharge side.
4, a condenser 2, an expansion valve 3, and an evaporator 5 are provided,
The outlet side of this evaporator 5 is connected to the suction side of the compressor 1. A circuit in which a pump 10 for transporting refrigerant liquid and a solar collector 7 are connected in series is branched from the main piping system between an expansion valve 3 and a condenser 2, and a connecting conduit on the outlet side of the solar collector 7 is connected to a check valve 14. is connected to the main piping system on the outlet side of the connecting conduit, in which a check valve 11 is arranged. Thereby, the solar collector 7 is in a parallel relationship with the condenser 2.

Note that on the Mollier diagram, point A is the outlet of the compressor 1, point B is in front of the expansion valve 3, point C is the inlet of the evaporator 5, and point D is the inlet of the evaporator 5.
The dot indicates the inlet of the compressor 1, the solid line A-B indicates the state inside the condenser 2, and the broken line B-A indicates the state inside the solar collector 7.
Indicates the internal state. The capacity of the compressor 1 is desirably controlled by an inverter or the like.

Next, the operation of the solar heat pump device of the present invention configured as above will be explained. First, when there is sufficient solar radiation, the compressor 1 is stopped and the pump 10 is operated. The liquid refrigerant sent from the pump 10 is heated, boiled, and evaporated by sunlight in the solar collector 7, passes through the check valve 11, enters the condenser 2, condenses there, becomes liquefied, and returns to the pump 10 again.

The flow of the refrigerant is represented by a solid line AB and a broken line BA on the Mollier diagram. According to this figure, it can be understood at a glance that the electrical input to the pump 10 is negligibly small.

Note that the refrigerant leaving the solar collector 7 is transferred to the compressor 1.
The flow to the evaporator 5 is prevented by the check valve 14. Solar collector 7 and condenser 2 at this time
The temperature and pressure of are almost equal.

Therefore, when trying to obtain high-temperature water in the hot water storage tank 9, it is recommended to use a collector with a selective absorption film, a collector with double glazing, or a collector with vacuum, which reduces the drop in heat collection efficiency even when the heat collection temperature becomes high in the solar heat collector 7. It is better to use a collector or the like.

In addition, when the weather is such that sufficient heat cannot be obtained from solar radiation alone, that is, when the amount of solar radiation is decreasing somewhat, or when the amount of solar radiation is intermediate,
Compressor 1 and pump 10 are operated simultaneously. The refrigerant discharged from the compressor 1 circulates through the check valve 14, the condenser 2, the expansion valve 3, and the evaporator 5. This flow is represented by a solid line A→B→C→D→A on the Mollier diagram.

On the other hand, part of the liquid refrigerant that has exited the condenser 2 is pumped 1
0, it is sent to the solar heat collector 7 and evaporated.

This flow is represented by the solid line A→B and the broken line B→A on the Mollier diagram. The solar heat collector 7 is located on the condensation side (high pressure side) of the refrigeration circuit, and operates as an evaporator to collect solar heat.

On the other hand, the evaporator 5 operates as a normal evaporator,
Collect outside heat. Compared to the amount of refrigerant circulating through the condenser 2, the amount of refrigerant sent out by the compressor 1 is small, resulting in energy-saving operation.

The capacity of the compressor 1 is controlled as necessary, taking into consideration the amount of solar radiation, outside temperature, and the like. Further, the power consumption per amount of energy conveyed by the pump 10 is extremely small.

Furthermore, when there is no solar radiation, only the compressor 1 is operated, and normal heat pump operation is performed. A check valve 11 prevents the refrigerant leaving the compressor 1 from flowing into the solar collector 7 .

In the above embodiment, the hot water supply system includes the condenser 2 in the hot water storage tank 9, but the condenser 2 may be a heating system in which a fin-and-tube heat exchanger and a fan are combined.

FIG. 5 shows another embodiment of a heating and cooling system, in which a four-way valve 15 is provided on the discharge side of the compressor 1 for switching the circuit during cooling and heating, and a four-way valve 15 is provided between the solar collector 7 and the pump 10 during cooling. A solenoid valve 16 is newly provided to prevent refrigerant from flowing into the solar collector. 5 is an outdoor heat exchanger, and 2 is a fin-and-tube type indoor heat exchanger.

In the case of the embodiment shown in FIG. 5, heating and cooling can be performed with one unit. The solar collector is used only for heating purposes.

Further, in the above embodiment, the check valves 11 and 14 are used to prevent the backflow of the refrigerant, but it goes without saying that these may be electromagnetic valves or the like. The solenoid valve corresponding to the check valve 11 is the pump 10
It is controlled to be open when it is operated and closed when it is stopped. Further, a solenoid valve corresponding to the check valve 14 is controlled to be open when the compressor 1 is operated and closed when the compressor 1 is stopped.

As described above, according to the solar heat pump device of the present invention, the solar heat collector and the pump for transporting the refrigerant liquid are provided in parallel with the condenser, so when there is sufficient solar radiation, solar heat can be generated with only a small pump input. In addition, not only when the amount of solar radiation has decreased somewhat, but also when the amount of solar radiation is intermediate, solar heat collectors use solar heat and evaporators use external heat in combination in an efficient and energy-saving manner. It is possible to achieve exceptional effects.

[Brief explanation of drawings]

1 and 2 are refrigerant circuit diagrams showing a hot water supply system of a conventional solar heat pump device, respectively. FIG. 3 is a refrigerant circuit diagram when an embodiment of the solar heat pump device of the present invention is applied to a hot water supply system. FIG. 4 is a Mollier diagram showing the operation of the solar heat pump device of FIG. 3, and FIG. 5 is a refrigerant circuit diagram when another embodiment of the solar heat pump device of the present invention is applied to an air conditioning system. 1... Compressor, 2... Condenser, 3... Expansion valve,
5... Evaporator, 7... Solar collector, 10... Pump, 11, 14... Check valve. (Parts 1 to 3 above)
Figure), 2...Indoor heat exchanger, 5...Outdoor heat exchanger,
15... Four-way valve, 16... Solenoid valve. (Part 5 above)
(Figure), and the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. In a solar heat pump device in which a compressor, a condenser, an expansion valve, and an evaporator are mutually connected to a main piping system so that refrigerant circulates, a connecting conduit is provided in parallel to the condenser, A pump, a solar collector, and a first check valve or electromagnetic valve are sequentially provided on this connecting conduit so as to circulate the refrigerant liquid from the outlet side of the condenser to the inlet side of the compressor, and A solar heat pump device characterized in that a second check valve or electromagnetic valve 14 is provided between the connecting conduit connecting portion in the main piping system.