JPS6294770A - Defrostation controller for 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 Industrial Application The present invention relates to a defrosting control device for an air conditioner.

Conventional technology Conventionally, defrosting control for heat pump air conditioners is as follows:
A reverse cycle in which four-way valves are switched is used (for example, Japanese Patent Laid-Open No. 77659/1983).

This will be explained below with reference to the drawings. Fig. 4 shows a refrigeration cycle diagram of a conventional air conditioner.
A four-way valve 2, an indoor heat exchanger 3, a pressure reducing device 4, and an outdoor heat exchanger 5 are sequentially connected by piping. During heating operation, the refrigerant gas leaving the compressor 1 condenses and radiates heat in the indoor heat exchanger as shown by the dashed arrow, passes through the pressure reducing device 4, absorbs heat and evaporates in the outdoor heat exchanger 5. It is sucked into the compressor 1.

When frost forms on the outdoor heat exchanger 5 at low outside temperatures, the defrost command switches the four-way valve 2 to transfer the high temperature refrigerant gas from the compressor 1 to the outdoor heat as shown by the arrow. A so-called reverse cycle defrosting method is adopted in which the air is sent to the exchanger 5 for defrosting.

Problems to be Solved by the Invention In such conventional defrosting, the refrigeration cycle switches to cooling operation mode during defrosting, so the indoor heat exchanger becomes an evaporator, and therefore heating operation is resumed after defrosting. Even if you restart
There was a problem that the heating feeling deteriorated due to warm air coming out, a drop in room temperature, and a lack of comfort.

In view of the above points, the present invention is intended to enable defrosting while remaining in the heating operation mode even during defrosting operation, thereby solving the conventional problems.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a solenoid valve that closes during defrosting operation between the outdoor heat exchanger of the refrigeration cycle and the four-way valve. A pressure regulating valve is provided in parallel.

According to the above configuration, the present invention enables the operation of the pressure regulating valve installed in parallel with the solenoid valve by closing the solenoid valve during defrosting operation, and the pressure regulating valve enables the operation of the pressure regulating valve in parallel with the solenoid valve. By maintaining high evaporation pressure, defrosting can be performed while in heating mode.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a refrigeration cycle diagram of an embodiment of the present invention, in which 1 is a compressor and 2 is a four-way valve.

3 is an indoor heat exchanger, 4 is a pressure reducing device, 5 is an outdoor heat exchanger, 6 is a pressure regulating valve, and 7 is a solenoid valve.

Furthermore, the flow directions of the four mediums during cooling, heating, and defrosting are indicated by arrows.

Fig. 2 is a time chart showing the operating states of the solenoid valve and four-way valve during defrosting. OFF turns the solenoid valve ON. The four-way valve remains ON.

Now, considering the case where the defrosting command is turned ON and the solenoid valve 7 is turned OFF, the operation of the pressure regulating valve 6 becomes effective at this time, and the evaporation pressure of the outdoor heat exchanger 5 during defrosting is The pressure will be maintained at the set pressure of the pressure regulating valve. As a result, the refrigeration cycle remains in the heating operation mode, but the evaporation pressure is maintained high, making defrosting possible.

After that, when the defrost command turns OFF, the solenoid valve is turned ON.
Therefore, the pressure regulating valve is bypassed and the normal heating operation mode is returned. Since the indoor heat exchanger 3 functions as a condenser even during defrosting, heating start-up characteristics after defrosting are improved.

FIG. 3 shows a time chart of another embodiment of the present invention, in which T1 is the main defrosting time, T3 is the sub-defrosting time, and T2 is the sub-defrosting interval time. T4 is the time for the sub-defrosting and main defrosting to occur, and T4 < T2. In this example, sub-defrosting is carried out at cycle T2 for a short time of 4 hours called T3 between the time intervals of main defrosting, in order to suppress the speed of frost formation as much as possible while heating operation. There is.

Effects of the Invention As described above, according to the present invention, defrosting control of an air conditioner can be performed with an extremely simple configuration in which a conventional refrigeration cycle is provided with a solenoid valve and a pressure regulating valve. It has excellent effects such as improving the room temperature drop during frost, preventing the feeling of cold wind, and improving the feeling of heating.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle diagram of an air conditioner according to an embodiment of the present invention, FIG. 2 is a time chart during defrosting, and FIG. 3 is a time chart during defrosting according to another embodiment of the present invention. FIG. 4 is a refrigeration cycle diagram of a conventional air conditioner. 1... Compressor, 2... Four-way valve, 3...
... Indoor heat exchanger, 4... Pressure reduction device, 5...
...Outdoor heat exchanger, 6...Pressure regulating valve, 7
······solenoid valve. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure ← Reibo ←-1 Warm 7;r ・Temi=・===ko Defrosting Figure 2 Figure 3 Yu

Claims (1)

[Claims] A compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger are connected via piping in sequence, and a solenoid valve that closes during defrosting operation is provided between the outdoor heat exchanger and the four-way valve. , a defrosting control device for an air conditioner, which includes a pressure regulating valve in parallel with the solenoid valve.