JPS6216596Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement in the operation control device of an air conditioner consisting of a heat pump type refrigeration cycle equipped with a refrigerant heater that improves the heating capacity when the outside temperature is low. Sometimes, by operating the on-off valve that communicates the high pressure side and the low pressure side with a certain period of delay from the start of the compressor, smooth circulation of refrigerant to the indoor heat exchanger and refrigerant heater is performed. The purpose is to ensure appropriate circulation of refrigerant in the refrigeration cycle and to prevent a decrease in heating capacity and a sudden rise in temperature of the refrigerant.

Hereinafter, the present invention will be described with reference to the accompanying drawings showing one embodiment thereof.

In the figure, 1 is a compressor, 2 is a four-way switching valve,
3 is an indoor heat exchanger, 4 is a pressure reduction mechanism, 5 is an outdoor heat exchanger, 6 is a refrigerant heater that heats the return pipe to the compressor 1, and the refrigerant heater 6 contains water, etc. A heat medium 6a, a heat source 6b for heating the heat medium 6a, and the like are provided. 7 and 8 are electromagnetic on-off valves that control the flow of the refrigeration cycle. Reference numeral 9 denotes an on-off valve that controls communication between the discharge pipe and the suction pipe of the compressor 1. A well-known refrigeration cycle is constructed by connecting these in an annular manner as shown in the figure. In addition, in the figure, A is the indoor unit,
B is an outdoor unit, and C is a refrigerant heater.

In the above configuration, during cooling operation, the refrigerant discharged from the compressor 1 is transferred to the four-way switching valve 2, the outdoor heat exchanger 5, the pressure reduction mechanism 4, the indoor heat exchanger 3, and the four-way switching valve as shown by the broken line arrow. 2 and returns to the compressor 1.

In addition, in heating operation using a normal heat pump system, the refrigerant discharged from the compressor 1 is transferred to the four-way switching valve 2, the indoor heat exchanger 3, the pressure reduction mechanism 4, the on-off valve 8, and the outdoor heat exchanger as shown by the solid arrow. A refrigeration cycle is configured in which the compressor 1 returns to the compressor 1 through the compressor 5 and the four-way switching valve 2.

Next, when performing a refrigerant heating operation using the refrigerant heater 6, the refrigerant is transferred to the compressor 1,
The refrigeration cycle passes through the four-way switching valve 2, the indoor heat exchanger 3, the on-off valve 7, enters the refrigerant heater 6, and returns to the compressor 1, and the refrigeration cycle returns from the compressor 1 through the on-off valve 9 to the compressor 1. constitutes one cycle. However, in the case of refrigerant heating operation, since the on-off valve 8 is closed, the refrigerant does not pass through the outdoor heat exchanger 5.

Next, when starting a refrigerant heating operation using the refrigerant heater 6, the on-off valve 7 is opened and the on-off valve 8 is closed. Therefore, after the refrigerant discharged from the compressor 1 exchanges heat with indoor air in the indoor heat exchanger 3, the on-off valve 8 is closed and the on-off valve 7 is open, so that the refrigerant is heated. The refrigerant flows into the refrigerant 6, takes in heat from the heat source 6b into the refrigerant, and returns to the compressor 1, forming a refrigeration cycle. After operating for a certain period of time, the on-off valve 9, which communicates the discharge side and suction side of the compressor, is opened to start normal refrigerant heating operation.

That is, in the refrigerant heating operation using the refrigerant heater 6, the discharge side and the suction side of the compressor 1 are communicated, a part of the refrigerant in the refrigeration cycle is bypassed, and the indoor heat exchanger 3 and the refrigerant heater are connected. However, if the on-off valve 9 is opened at the same time as the start-up, all of the refrigerant will bypass the on-off valve 9, making it impossible to obtain the desired refrigerant heating operation. This may cause a decrease in heating capacity or a sudden rise in temperature of some refrigerants.

Therefore, when starting the refrigerant heating operation, the on-off valve 9 that communicates the discharge side and the suction side of the compressor 1 is
By opening the compressor after a certain period of time delay from the start of the compressor, a predetermined amount of refrigerant circulation can be obtained, and at the same time, a large amount of refrigerant flows to the indoor heat exchanger and refrigerant heater without flowing through the pressure reduction mechanism. The opening/closing valve 9 has good start-up characteristics and can be used even when it gets cold indoors and the refrigerant accumulates in liquid form in the indoor heat exchanger.
Since the refrigerant is closed, the refrigerant pressure increases and the refrigerant flows to the indoor heat exchanger and the refrigerant heater. Therefore, the amount of refrigerant is not insufficient, and after the on-off valve 9 is closed for a certain period of time, a stable cycle is established and the on-off valve 9 remains open, so the refrigerant is bypassed to the discharge side and the suction side, and the difference between high and low pressures is small. Therefore, the electrical input to the compressor can be reduced.

As is clear from the above embodiments, the heating operation control device for an air conditioner according to the present invention is capable of shutting down the bypass circuit for a certain period of time even if the device is operated with refrigerant accumulated in the indoor heat exchanger or the like in a liquid state. By being closed, the refrigerant pressure increases, so there is no shortage of refrigerant due to flowing into the indoor heat exchanger and refrigerant heater. Therefore, it is possible to ensure the amount of refrigerant circulated within the refrigeration cycle that provides a predetermined heating capacity, and to prevent a local temperature rise of the refrigerant.

Furthermore, after the delay for a certain period of time, the refrigerant flows to the bypass circuit and the operation is performed with a small amount of refrigerant circulation, so that electrical input can be reduced and noise can also be reduced.

Furthermore, after the bypass circuit is opened, a large amount of oil discharged from the compressor flows into the bypass circuit, and the amount of oil flowing to the refrigerant heater side is reduced, which reduces oil deterioration due to the heat of the refrigerant heater. Also, by returning a large amount of oil to the compressor, it is possible to prevent seizure of the sliding parts, which is particularly effective during long-term use.

[Brief explanation of the drawing]

The figure is a refrigeration cycle diagram of an air conditioner equipped with an operation control device according to an embodiment of the present invention. 1... Compressor, 2... Four-way switching valve, 3... Indoor heat exchanger, 4... Pressure reduction mechanism, 5... Outdoor heat exchanger, 6... Refrigerant heater, 7, 9... Open/close valve.

Claims (1)

[Scope of utility model registration request] A refrigeration cycle is constructed by connecting a compressor, an indoor heat exchanger, a pressure reducing mechanism, and an outdoor heat exchanger in a ring, and a valve mechanism that opens during refrigerant heating operation is provided in parallel with the pressure reducing mechanism and the outdoor heat exchanger; A refrigerant heater is provided, a valve mechanism that is closed during refrigerant heating operation is provided in the inflow side piping of the outdoor heat exchanger, and a bypass pipe that connects the high pressure side piping and the low pressure side piping of the compressor is provided in the refrigerant heating operation. A heating operation control device for an air conditioner equipped with an on-off valve that opens after a certain period of time from the start.