JPS62200148A - 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 Field of the Invention The present invention relates to hot gas defrosting in heat pump air conditioners.

BACKGROUND OF THE INVENTION Conventionally, the outdoor heat exchanger of a heat pump type air conditioner functions as an evaporator during heating operation, so frost can adhere to it depending on outside air conditions. Frost reduces heat absorption in the outdoor heat exchanger, reducing heating capacity.

Defrosting is performed to prevent this reduction in heating capacity.

The defrosting operation of a conventional heat pump air conditioner will be described below with reference to the drawings.

FIG. 2 shows a refrigeration cycle of a conventional heat pump type air conditioner. In Fig. 2, 1 is a compressor, 2
is a four-way valve, 3 is an outdoor heat exchanger, 4 is a heating diaphragm, 6 is a reverse valve, 6 is a first communication pipe, 7 is a cooling diaphragm, 8 is an indoor heat exchanger, 9 is a second communication tube, 1o is accumulator, 1
1 is a liquid bypass circuit, 12 is a two-way valve, and these are successively communicated to form a refrigeration cycle.

The defrosting operation of the heat pump air conditioner configured as above will be explained.

In the conventional defrosting operation, the four-way valve 2 is switched to send refrigerant gas to the outdoor heat exchanger 3 to radiate heat and melt the frost that has formed on the outdoor heat exchanger 3 during the heating operation. At this time, when the defrosting operation starts, the liquid flows into the bypass circuit 11 side and is returned directly into the accumulator 10. As a result, the suction pressure of the compressor 1 increases compared to when the liquid bypass is not performed, so the amount of refrigerant discharged increases, and the amount of circulation to the outdoor heat exchanger 3 increases. Since the amount of heat given to melt the frost is increased compared to the case without liquid bypass, the defrosting time can be shortened.

Problems to be Solved by the Invention However, the liquid bypass circuit 1 uses refrigerant with low dryness.
compressor 1 for direct return to the accumulator via 1
This has the problem that refrigerant with low dryness is sucked in, which is one of the major factors that impairs the reliability of the compressor 1 such as liquid compression.

In view of the above-mentioned problems, the present invention mixes the discharged gas refrigerant with the refrigerant with low dryness obtained from the liquid bypass during the defrosting operation, thereby increasing the dryness of the refrigerant entering the accumulator. The present invention provides a heat pump type air conditioner that prevents liquid compression in the compressor that occurs in the first place.

Means for Solving the Problems In order to solve the above problems, the heat pump air conditioner of the present invention has a liquid bypass circuit connected to a hot gas bypass circuit for guiding discharged gas to the liquid bypass circuit. It has a configuration.

According to the above-described configuration, the present invention allows the refrigerant with low dryness to flow into the accumulator through the liquid bypass circuit during defrosting operation, and transfers the discharged gas with high dryness to the liquid bypass circuit before flowing into the accumulator. By mixing both refrigerants through a hot gas bypass circuit connected to
The dryness of the refrigerant flowing into the accumulator can be increased, and the refrigerant sucked into the compressor is always dry or overheated, so the compressor does not compress liquid.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings regarding a heat pump type air conditioner. FIG. 1 shows a refrigeration cycle of a heat pump air conditioner according to an embodiment of the present invention. In addition, the same reference numerals are attached to the same configurations as in the prior art, and detailed explanation thereof will be omitted.

In Figure 1, 13 is the hot gas bypass circuit!
lla, connected to the bypass circuit 11. The hot gas bypass circuit 13 is provided with a second two-way valve 14° and a bypass throttle 16.

The operation of the heat pump air conditioner configured as described above will be explained below using FIG. 1.

During heating operation, sod adheres to and grows on the outdoor heat exchanger 3.

Then, defrosting is performed to prevent the heating capacity from decreasing due to this drying. Next, when the amount of frost increases and defrosting becomes necessary, the four-way valve 4 switches to the cooling cycle and enters defrosting operation. At the same time, the first two-way valve 12 of the liquid bypass circuit 11 and the second two-way valve 14 of the hot gas bypass circuit 13 are opened.

The refrigerant entering the accumulator 10 from the liquid bypass circuit 11 is mixed with the superheated gas refrigerant whose pressure has been reduced by the bypass restrictor 16 of the hot gas bypass circuit 13, and has a high degree of dryness.
Alternatively, the refrigerant becomes too hot and is sucked into the compressor 1.

As described above, according to this embodiment, by connecting the hot gas bypass circuit to the liquid bypass circuit, the compressor always takes in dry or overheated refrigerant. This improves the reliability of the refrigeration system.

Effects of the Invention As described above, the present invention provides a refrigeration system in a heat pump type air conditioner consisting of a liquid bypass circuit equipped with a two-way valve and a hot gas bypass circuit connected to the liquid bypass circuit and equipped with a two-way valve and a bypass throttle. By opening the fan valve at the same time during frost operation, the state of the refrigerant sucked into the compressor can always be dry or overheated, preventing liquid compression in the compressor and improving the reliability of the refrigeration system. can do.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle diagram of a heat pump type air conditioner according to an embodiment of the present invention, and FIG. 2 is a refrigeration cycle diagram of a conventional heat pump type air conditioner. 1... Compressor, 2... Four-way valve, 3...
...Outdoor heat exchanger, 4...Heating diaphragm,
5... Check valve, 6... First communication pipe, 7
...Air conditioner diaphragm, 8...Indoor heat exchanger, 1o...Accumulator, 11...
...Liquid bypass circuit, 12...First two-way valve, 1
3...Hot gas bypass circuit, 14...
...? J2 two-way valve, 15... Bypass throttle. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (1)

[Claims] Compressor, four-way valve, outdoor heat exchanger, heating diaphragm, check valve installed in parallel to heating diaphragm, first communication pipe, cooling diaphragm, indoor heat exchanger, second communication pipe, and accumulator in sequence. A refrigeration cycle configured to communicate with each other, a liquid bypass circuit connecting the heating throttle and the first communication pipe, and the accumulator inlet pipe via a valve, and a discharge pipe of the compressor. and a hot gas bypass circuit provided with a second two-way valve and a bypass throttle in the liquid bypass circuit between the first two-way valve provided in the liquid bypass circuit and the accumulator inlet pipe. Heat pump air conditioner.