JPS62284157A - Heat pump type air conditioner - 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 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to shortening the defrosting time of a heat pump type air conditioner.

BACKGROUND OF THE INVENTION In recent years, with the aim of improving the comfort of heat pump air conditioners, methods have been actively developed to shorten the defrosting time, particularly in order to reduce the drop in room temperature during defrosting.

An example of a conventional heat pump air conditioner will be described below with reference to the drawings. FIG. 3 shows a refrigeration cycle of a conventional heat pump air conditioner. In Fig. 3, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger,
4 is a cooling diaphragm device, 6 is a heating diaphragm device, 〇 is an outdoor heat exchanger, 7 is an accumulator, and 8 and 9 are inverse diaphragm devices arranged in parallel with each of the cooling diaphragm device 4 and the heating diaphragm device S. It is a stop valve.

The operation of the heat pump air conditioner configured as above will be described below.

When the outside temperature is low and the humidity is high, frost begins to adhere to the outdoor heat exchanger 6 and grows during heating operation. And as the frost grows, heating capacity decreases. In order to prevent this reduction in heating capacity, it is necessary to defrost regularly. When defrosting is required, the four-way valve 2 receives the defrost start signal and switches from the heating circuit to the cooling circuit, and reverse cycle defrost (hot gas) is started, causing the outdoor heat exchanger 6 to receive hot gas. Gas is sent to melt the frost attached to the outdoor heat exchanger 6.

When defrosting is finished, the four-way valve 2 returns to the heating circuit again, and heating operation continues.

Problems to be Solved by the Invention However, in the above configuration, the cooling throttling device 4 during reverse cycle defrosting during defrosting creates a large flow path resistance, and the refrigerant flows to the outdoor heat exchanger 6 and the cooling throttling device 4. The refrigerant becomes clogged in the piping, and the pressure on the low pressure side drops significantly.

Therefore, the amount of refrigerant discharged by the compressor 1 decreases, the amount of sensible latent heat of the refrigerant used for defrosting decreases, and the defrosting time tends to become longer. Further, during heating operation, a considerable amount of refrigerant is stored in the outdoor heat exchanger 6, and most of the refrigerant is in a liquid refrigerant state. If you switch to defrosting operation in this state, immediately after switching, the hot gas will mix with the liquid refrigerant stored in the outdoor heat exchanger, and the latent heat of the liquid refrigerant will be taken away from the hot gas, causing the defrost to be removed. The problem is that the heat of the hot gas is not effectively used against frost, resulting in a longer defrosting time.

In view of the above-mentioned problems, the present invention provides a defrosting device for a heat pump type air conditioner that can prevent heat loss of hot gas during defrosting and shorten defrosting time.

Means for Solving the Problems In order to solve the above problems, the heat pump air conditioner of the present invention includes a compressor, a four-way valve, and an indoor heat exchanger.

A refrigeration cycle is configured by sequentially communicating a cooling throttle device, a heating throttle device, an outdoor heat exchanger, and an accumulator, and a discharge pipe of the compressor, the heating throttle device, and the outdoor heat exchanger. It consists of a hot gas bypass circuit having a solenoid valve A between, a solenoid valve B arranged in series with the heating throttle device, and a solenoid valve C arranged in parallel with the heating throttle device and the solenoid valve C, In response to the defrosting start signal from the defrosting detector, the solenoid valve B is first opened and then closed, and then returned to its original open state after defrosting is completed. In addition, after a certain period of time has elapsed after the solenoid valve B is closed, the solenoid valve C is changed from the closed state to the open state and returned to the closed state after a certain period of time, and at the same time, the solenoid valve A is also changed from the closed state to the open state for hot gas defrosting. After defrosting is completed, the system is closed and heating operation is performed.

Effects The present invention has the above-described configuration, and by closing the solenoid valve B, the liquid refrigerant accumulated in the outdoor heat exchanger during the heating operation is removed before full-fledged defrosting operation is performed using the hot gas bypass circuit.
The pump is pumped down, the outdoor heat exchanger is brought to a near vacuum state, and most of the refrigerant is stored on the high pressure side.Then, the high temperature and high pressure gas is guided to the outdoor heat exchanger by opening the solenoid valve C. By heating the frost and outdoor heat exchanger, and then defrosting with hot gas by opening the solenoid valve A of the hot 7h gas bypass circuit, the defrosting time can be significantly shortened.

EXAMPLE Hereinafter, a heat pump type air conditioner according to an example of the present invention will be described with reference to the drawings. FIG. 1 shows a refrigeration cycle of a heat pump air conditioner according to an embodiment of the present invention. FIG. 2 is a chart showing the operating states of the main elements constituting the present invention. It should be noted that the same components as those in the prior art are given the same reference numerals, and detailed explanation thereof will be omitted.

In FIG. 1, 1o is a solenoid valve B, and a heating throttle device 5
are arranged in series. Reference numeral 11 denotes a solenoid valve C, which is arranged in parallel with the heating diaphragm device 5 and the solenoid valve B8. Reference numeral 12 denotes a gas binox circuit, which connects the discharge pipe of the compressor 1, the heating throttle device 6, and the outdoor heat exchanger 6, and is provided with solenoid valves A and 13 in the middle.

The operation of the heat pump air conditioner configured as described above will be explained below with reference to FIG.

When the frost adhering to the outdoor heat exchanger 6 grows during heating operation, the defrost detector issues a defrost start signal. This signal first changes the solenoid valve B10 from an open state to a closed state. At this time, during the heating operation, about 30% of the total amount of refrigerant is stored in the outdoor heat exchanger 6, and most of it is liquid refrigerant. By closing the electromagnetic valve B1o, most of the refrigerant stored in the outdoor heat exchanger 6 is sucked into the compressor 1, and the outdoor heat exchanger 6 becomes almost free of refrigerant. At the same time, the refrigerant on the high-pressure side, which is the indoor heat exchanger 3 and its piping, becomes even more high-temperature and high-pressure.

When the high pressure side reaches a certain pressure and temperature after the solenoid valve B10 is closed, or after a certain period of time has passed, the solenoid valve C1 is closed.
1 from the closed state to the open state, the refrigerant stored on the high pressure side flows into the outdoor heat exchanger 6, heats the frost and the outdoor heat exchanger 6, and melts some of the frost. At this time, heating operation is being carried out, and the decrease in capacity has been kept to a minimum. After a certain period of time and at the same time when the solenoid valve C11 is closed, the hot gas bypass circuit 12
The solenoid valve A13 is changed from the closed state to the open state, and the hot gas discharged from the compressor 1 is allowed to flow into the outdoor heat exchanger 6, thereby making it possible to completely melt the frost that has already partially melted.

As described above, according to this embodiment, the solenoid valve B is designed to minimize the amount of refrigerant stored in the outdoor heat exchanger 6 during heating operation.
10, a solenoid valve C13 for melting and heating a portion of the frost on the outdoor heat exchanger 6 to which frost has adhered during heating operation, and a hot gas bypass circuit for defrosting without switching the four-way valve. By providing the solenoid valve A13 for controlling the four-way valve, it is possible to shorten the defrosting time and eliminate unpleasant noise when switching the four-way valve.

Effects of the Invention As described above, the present invention provides a solenoid valve provided in a hot gas bypass circuit, a solenoid valve provided in series with a heating throttle device,
By arranging a solenoid valve in parallel with the heating/air conditioning diaphragm device and the solenoid valve, the defrosting time can be significantly shortened compared to the conventional method, and defrosting can be performed without switching the four-way valve. It is possible to eliminate unpleasant noise when switching the four-way valve, and improve the comfort of the heat pump air conditioner.

[Brief explanation of drawings]

Fig. 1 is a refrigeration cycle diagram of a heat pump air conditioner according to an embodiment of the present invention, Fig. 2 is a time chart showing the operating states of the main elements constituting the present invention, and Fig. 3 is a diagram of a conventional heat pump air conditioner. It is a refrigeration system diagram. 1... Compressor, 2... Four-way valve, 3...
...Indoor heat exchanger, 4...Cooling diaphragm, 5
... Heating diaphragm, 6 ... Outdoor heat exchanger, 7 ... Accumulator, 8 ... Solenoid valve B, 9 ... Solenoid valve C110... E, Nodule gas bypass circuit, 11... Solenoid valve 80 Name of agent: Patent attorney Toshio Nakao and one other person Figure 2

Claims (1)

[Claims] A refrigeration cycle configured by sequentially communicating a compressor, a four-way valve, an indoor heat exchanger, a cooling throttle device, a heating throttle device, an outdoor heat exchanger, and an accumulator; a discharge pipe of the compressor; Between the heating diaphragm and the outdoor heat exchanger,
It consists of a hot gas bypass circuit having a solenoid valve A, a solenoid valve B arranged in series with the heating throttle device, and a solenoid valve C arranged in parallel with the heating throttle device and the solenoid valve B,
In response to the defrost start signal from the defrost detector, first the solenoid valve B is opened and then closed, and after defrosting is completed, the solenoid valve B is returned to the open state, and after a certain period of time after the solenoid valve B is closed, the solenoid valve C is closed. A heat pump characterized in that it changes from a closed state to an open state, returns to a closed state after a certain period of time, and at this time simultaneously changes a solenoid valve A from a closed state to a closed state to perform hot gas defrosting, and after defrosting is completed, closes it to perform a heating operation. type air conditioner.