JPH01222173A - Heat pump system - Google Patents

Abstract

PURPOSE:To improve the stabilization of a circuit during defrosting operation and shorten the defrosting time as well, by providing a third refrigerant circuit where the inlet side of a condenser is connected to the outlet side of a second pressure reducing device in a second refrigerant circuit by way of a third pressure reducing device and a fifth on/off valve. CONSTITUTION:When a heat pump system enters into a defrosting operation, on/off valves 9, 11, and 15 are opened while on/off valves 8 and 10 are closed. Then, refrigerant gas sent from a compressor 1 partially enters a third refrigerant circuit 16, passes through a third pressure reducing device 3b, and a fifth on/off valve 15, then enters a vaporizer 4. The rest of the refrigerant is sent to a condenser 2 where the heat is radiated and heating is carried out. The quantity of refrigerant gas, which flows into a cooling circuit 16, is controlled from the quantity of refrigerant throttled by the quantity of a pressure reducing device 3b so that liquid may be constantly kept on the inlet side of a second pressure reducing device 3a. The pressure of the refrigerant which enters the vaporizer 4 is not subjected to a sudden change against a change in the quantity throttled by the pressure reducing device 3a so that it can be sent to a vaporizer 4 at the optimum refrigerant pressure. The refrigerant which has passed through the refrigerant circuit 16 joins the refrigerant, which has left the pressure reducing device 3a, at the inlet side of the vaporizer 4 and is sent under a gas-liquid phase status where all of them are subjected to condensation, radiating heat, then turned into refrigerant liquid, thereby carrying out defrosting from the vaporizer 4.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a heat pump device with improved defrosting performance.

[Conventional technology]

FIG. 2 is a block diagram of a refrigerant circuit of a seven-tooth pump device using a heat storage tank, as disclosed in, for example, Japanese Patent Laid-Open No. 175559/1982. In FIG. 2, 1 is a compressor, 2 is a condenser, 3 and 3a are expansion valves or capillary tubes, etc.
and a second pressure reducing device, 4 is an evaporator, and 5 is a heat storage built in a heat storage tank 6 together with a heat storage material 7 having a phase change temperature between 0 and 30°C. Heat exchanger for heat absorption, 8 to 11 are first to fourth on-off valves, I
2 is a first refrigerant circuit, 13 is a second refrigerant circuit, and 14 is a defrosting refrigerant circuit. The compressor 1, the condenser 2, the first pressure reducing device 3, and the evaporator 4 are connected in an annular manner.
The cycle is configured. This refrigeration cycle has a first on-off valve 8. between the outlet side of the condenser 2 and the outlet side of the evaporator 4. Heat exchanger5. A first refrigerant circuit 12 to which a first pressure reducing device 3 and an evaporator 4 are connected in this order, and a second on-off valve 9
and a second refrigerant circuit 13 in which the second pressure reducing device 3a is connected in this order are connected in parallel. Also, 1st. The part where the second refrigerant circuits 12 and 13 join on the outlet side of the evaporator 4 is connected to the suction side of the compressor 1 via the third on-off valve 10, and further connected to the first on-off valve 8 and the heat exchanger. 5 is provided with a defrosting refrigerant circuit 14 connected to the suction side of the compressor 1 via a fourth on-off valve 11. Next, the operation of the refrigerant circuit of this heat pump device will be explained. First, during heating operation, 1. The third on-off valve 8°10 opens, and the second on-off valve 8°10 opens. The fourth on-off valves 9 and 11 close. Then, the refrigerant flows as shown by solid arrows in FIG. 5, and the high-temperature, high-pressure refrigerant gas discharged from the compressor 1 is sent to the condenser 2, where it radiates heat for heating and is condensed and liquefied. The refrigerant liquid at around 40°C that exerts a heating effect and exits the condenser 2 is transferred to the first refrigerant circuit 12.
is sent from the first on-off valve 8 to the heat exchanger 5 in the heat storage tank 6, and the phase change moisture content filled in the heat storage tank 6 is 0 to 3.
The M heat material 7 at a temperature between 0° C. is heated and heat is stored therein. The refrigerant liquid that has exited the heat exchanger 5 is depressurized through the first pressure reducing device 3 to have a low temperature and low pressure, and then is sent to the evaporator 4 where it is evaporated. The evaporated refrigerant gas passes through the third on-off valve 10 and returns to the compressor 1, repeating the cycle. In this operation,
When the outside temperature is low and the evaporation temperature of the refrigerant is 0° C. or lower, frost adheres to the heat transfer surface of the evaporator 4, resulting in a reduction in heating capacity. Therefore, a defrosting operation is required to remove the frost, and this operation is performed next. During fog removal operation, 1. The third on-off valves 8, 10 are closed, and the second on-off valves 8, 10 are closed. The fourth on-off valves 9 and 11 open, and the refrigerant flows as shown by the dashed arrow in Fig. 2, and the high-temperature, high-pressure refrigerant gas discharged from the compressor 1 is sent to the condenser 2, where it radiates heat. Heating takes place. However, the refrigerant gas does not exert its heating effect at all, and passes through the second refrigerant circuit 13 in a gas-liquid mixed state with some refrigerant gas remaining, and is passed from the second on-off valve 9 to the second pressure reducing device 3a. Be sent to. Here, the gas-liquid two-phase refrigerant is reduced to an intermediate pressure, and is sent to the evaporator 4 with a condensation temperature of about 10°C to 20°C, where it radiates heat and condenses as a whole. It becomes a refrigerant liquid. The frost adhering to the evaporator 4 is melted by this heat radiation, and defrosting is performed. The refrigerant liquid exiting the evaporator 4 passes through the first pressure reducing device 3 of the first refrigerant circuit 12, becomes low profile and has a low pressure, and is sent to the heat exchanger 5 in the heat storage tank 6. Here, the refrigerant liquid absorbs heat from the heat storage material 7, evaporates, becomes refrigerant gas, passes through the defrosting refrigerant circuit 14, returns to the compressor 1 via the fourth on-off valve 11, and continues until defrosting is completed. When defrosting is completed, the first to fourth on-off valves 8 to 11 return to the heating operation state,
Heating operation will resume.

[Problem M that the invention attempts to solve]

In the conventional heat pump device, as mentioned above during defrosting operation, the refrigerant is in a gas-liquid two-phase state at the outlet of the condenser, so even a slight change in the throttle amount of the first pressure reducing device will cause the refrigerant to flow into the evaporator. There was a problem in that the pressure of the refrigerant entering the evaporator varied greatly, making it difficult to control the pressure of the refrigerant entering the evaporator, making it impossible to perform optimal defrosting operation. This invention was made to solve the above problems, and it is possible to achieve optimal control of the pressure of the refrigerant entering the evaporator, thereby shortening the defrosting time and increasing the heating capacity during defrosting operation. The aim is to obtain a heat pump device that can achieve optimization of fog removal operation, such as ensuring

[Means to solve the problem]

In the heat pump device according to the present invention, in which the inlet side of the condenser is connected to the outlet side of the second pressure reducing device of the second refrigerant circuit, a third pressure reducing device and a fifth pressure reducing device are arranged. It is equipped with a third refrigerant circuit connected via an on-off valve.

[For production]

The heat pump device according to the present invention, during defrosting operation,
The fifth on-off valve provided in the third refrigerant circuit opens and a portion of the discharged gas is bypassed without passing through the condenser so that the refrigerant at the condenser outlet is always in a liquid state. It is possible to easily control the throttling amount of the pressure reducing device, optimize the refrigerant pressure in the evaporator, and perform defrosting operations efficiently.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a refrigerant circuit diagram of a pump device according to an embodiment of the present invention. In FIG. 1, 1 is a compressor, 2 is a condenser, and 3 and 3a are expansion valves or capillary tubes. first and second pressure reducing devices, 4 an evaporator, 5 a heat exchanger for heat storage and heat absorption built in a heat storage tank 6 together with a heat storage material 7 having a phase change temperature between 0 and 30°C; 11 is the first to fourth on-off valve, 12 is the first refrigerant circuit, and 13 is the second
The refrigerant circuit 14 is a defrosting refrigerant circuit, and the first refrigerant circuit 12 and the second refrigerant circuit 13 are connected in parallel between the outlet side of the condenser 2 and the outlet side of the evaporator 4. The above configuration is similar to the conventional one shown in FIG. 16 is a third pressure reducing device 3b such as an expansion valve or a capillary tube.
and a fifth on-off valve 15 in this order, and both ends thereof are connected to the inlet side of the IS device 2 and the outlet side of the second pressure reducing device 3a. Next, the operation of the refrigerant circuit of the tort pump device configured as described above will be explained. During heating operation, 1. The third on-off valves 8 and 10 open, and the second. 4th. The fifth on-off valves 9, 11, and 15 are closed, and the heat exchanger 5 in the heat storage tank 6 is similar to the conventional one described above.
The refrigerant liquid enters from the condenser 2 and heats the heat storage material 7 whose phase change temperature is between 0 and 30°C to generate M heat. And heat exchanger 5
The refrigerant liquid that has exited is throttled and depressurized by the first pressure reducing device 3, evaporated by the evaporator 4, and returned to the compressor 1. When frost adheres to the evaporator 4 and the defrosting operation begins, the second.
4th. The fifth on-off valve 9, 11, 15 opens, and the first. Third
The on-off valves 8 and 10 are closed, and the refrigerant flows as shown by the dashed arrow in FIG. It passes through the third pressure reducing device 3b1 and the fifth on-off valve 15, enters the evaporator 4, and the remainder is sent to the condenser 2, where heat is radiated and heating is performed. Then, the third refrigerant circuit 1 is controlled so that the refrigerant at the condenser outlet 2 always becomes liquid by the throttling amount of the third pressure reducing device 3b.
By controlling the amount of refrigerant gas flowing into the second
The inlet side of the second pressure reducing device 3a is always liquid, and the pressure of the refrigerant entering the evaporator 4 does not change suddenly in response to changes in the throttling amount of the second pressure reducing device 3a, making it easy to control the throttling amount here. This makes it possible to send the refrigerant to the evaporator 4 at an optimal pressure. As mentioned above, the refrigerant that has passed through the third refrigerant circuit 16 and the second
The refrigerant that has exited the pressure reducing device 3a joins again at the inlet side of the evaporator 4 and is sent to the evaporator 4 in a two-phase gas-liquid state, where heat is radiated and the entire refrigerant condenses to become liquid refrigerant. The frost adhering to the evaporator 4 is melted by this heat radiation, and defrosting is performed. The refrigerant liquid that has left the evaporated N4 passes through the first pressure reducing device 3, the heat exchanger 5 in the heat storage tank 6, the fourth on-off valve 11, and is compressed 8!1, as in the conventional system described above. Repeat the above cycle until return defrosting is complete.

【Effect of the invention】

As explained above, according to the present invention, during defrosting operation, by controlling the amount of refrigerant entering the condenser with the third refrigerant device having the third pressure reducing device and the fifth on-off valve,
Since the refrigerant entering the second pressure reducing device is always in liquid form, the stability of the circuit during defrosting operation can be improved and the defrosting time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a refrigerant circuit of a heat pump device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a refrigerant circuit of a conventional heat pump device. 1... Compressor, 2... Condenser, 3, 3a, 3b
- 11th... 1st to 4th on-off valves, 12, 13 - 1st - 2nd refrigerant circuit, 14 - Defrosting refrigerant circuit, 15...
- Fifth on-off valve, 16... third refrigerant circuit. Note that the same reference numerals in the figures indicate the same or equivalent parts. Agent Masuo Oiwa (2 others) Figure 1 Figure 2

Claims (1)

[Claims] (1) It has a refrigeration cycle configured by connecting a compressor, a condenser, a first pressure reducing device, and an evaporator in a ring, and this refrigeration cycle has an outlet side of the condenser and an outlet side of the evaporator. In between, a first refrigerant circuit comprising a first on-off valve, a heat exchanger built into a heat storage tank together with a heat storage material, the first pressure reducing device and an evaporator in this order, and a second on-off valve. and a second refrigerant circuit equipped with a second pressure reducing device are connected in parallel, and the part where the first and second refrigerant circuits meet at the outlet side of the evaporator is connected to the compressor through a third on-off valve. The defrosting refrigerant circuit is connected to the suction side of the compressor, and further connected to the suction side of the compressor between the first on-off valve and the heat exchanger in the heat storage tank via a fourth on-off valve. In the heat pump device, the inlet side of the condenser is connected to the outlet side of the second pressure reducing device of the second refrigerant circuit, and a third
A heat pump device comprising a pressure reducing device and a third refrigerant circuit connected via a fifth on-off valve.