JPS5933817B2 - Refrigerant heating operation control method for air conditioners - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to control at the time of starting a refrigerant heating operation in an air conditioner comprising a heat pump refrigeration cycle equipped with a refrigerant heater that improves heating capacity at low outside temperatures. At the start of refrigerant heating operation, the refrigerant accumulated in the indoor heat exchanger, outdoor heat exchanger, refrigerant heater, etc. in the refrigeration cycle is promptly recovered to the compressor, thereby reducing the heating start-up during refrigerant heating operation. By shortening the time, the refrigerant pressure or temperature of a portion of the refrigerant in the refrigeration cycle suddenly increases, thereby preventing a phenomenon in which normal refrigerant heating operation cannot be continued.

In conventional refrigerant heating operation, the outdoor heat exchanger, etc. where refrigerant accumulates, is designed to be on the low pressure side and the refrigerant is gradually recovered while operation is continued, or a small amount of refrigerant accumulation is ignored. Since the refrigerant heating operation was continued during this period, the heating start-up time was long and it took a considerable amount of time until the refrigeration cycle stabilized and normal refrigerant heating operation could be performed.

The present invention eliminates the drawbacks found in the conventional air conditioner operation control described above.

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, and 6 is a refrigerant that heats the return pipe to the compressor 1. The refrigerant heater 6 includes a heat medium 6a such as water and a heat source 6b such as a gas burner for heating the heat medium 6a.

I is a first on-off valve, and 8 is a second on-off valve, which control the flow of the refrigeration cycle.

9 is an on-off valve that controls communication between the discharge pipe and the suction pipe of the compressor 1; 10 is an on-off valve that controls communication between the four-way switching valve 2 and the suction side of the compressor 1 in the heating cycle; This is a check valve that allows refrigerant to enter the suction side.

By connecting these in an annular manner as shown in the same figure, a well-known refrigeration cycle is constructed.

In the figure, A is the indoor unit, B is the indoor unit,
C is a refrigerant heating unit.

In the above configuration, during cooling operation, the refrigerant discharged from the compressor 1 passes through 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 2, and enters the compressor. 1
Configure the refrigeration cycle to return to.

In addition, in heating operation using a normal heat pump system, the refrigerant is discharged from the compressor 1, passes through the four-way switching valve 2, the indoor heat exchanger 3, the pressure reduction mechanism 4, the outdoor heat exchanger 5, and the four-way switching valve 2, and is compressed. A refrigeration cycle returning to machine 1 is constructed.

Next, when performing a refrigerant heating operation using the refrigerant heater 6, the refrigerant is supplied to the compressor 1, the four-way switching valve 2, the indoor heat exchanger 3,
A refrigeration cycle that passes through the first on-off valve γ, flows into the refrigerant heater 6 and returns to the compressor 1, and a third on-off valve 9 from the compressor 1.
This constitutes two cycles of the refrigeration cycle that returns to the compressor 1 through the

However, in the case of refrigerant heating operation, since the second on-off valve 8 is closed, the refrigerant does not pass through the outdoor heat exchanger 5.

In other words, the refrigerant heating operation using the refrigerant heater 6 is performed in the first
The on-off valve γ is opened, the second on-off valve 8 is closed, and the third on-off valve 9 is opened to form a refrigeration cycle in which no refrigerant flows into the outdoor heat exchanger 5. The refrigerant discharged from the refrigerant 1 exchanges heat with the indoor air in the indoor heat exchanger 3, and then flows into the refrigerant heater 6, where the heat from the heating source 6b is taken into the refrigerant and compressed. A refrigeration cycle returning to machine 1 is configured.

Here, when starting the refrigerant heating operation using the refrigerant heater 6, at the same time as starting the refrigerant heating operation, the first on-off valve 1 is opened, the second on-off valve 8 is closed, and the third on-off valve is closed. When the valve 9 is opened, the refrigerant accumulated in the outdoor heat exchanger 5 and the pipes is trapped, and as a result, the amount of refrigerant in the refrigeration cycle in which the refrigerant heating operation is performed is insufficient. This not only makes it impossible to obtain a predetermined refrigerant heating operation, but also causes a decrease in heating capacity and a rapid rise in temperature of a portion of the refrigerant.

Therefore, when starting the refrigerant heating operation, all of the on-off valves γ, 8, and 9 are closed for a certain period of time at the same time as the start, and the refrigerant accumulated in the outdoor heat exchanger 5 and piping is removed by the four-way switching valve 2, the reverse It is recovered to the compressor 1, four-way switching valve 2, and indoor heat exchanger 3 through the stop valve 10.

In other words, by collecting the refrigerant during the refrigeration cycle in which the refrigerant heating operation is performed, a predetermined amount of refrigerant can be secured during the refrigeration cycle, and an effective heating device can be obtained without a decrease in heating capacity or a sudden rise in temperature of a part of the refrigerant. Can be done.

In addition, after the refrigerant is recovered, if the third on-off valve 9 is not present, the refrigerant will not flow through the pressure reducing mechanism, so the pressure difference between the high pressure side and the low pressure side of the compressor will be small, resulting in an excessive amount of refrigerant circulation. Although the refrigerant leaving the heater 6 is not completely gasified and returns to the compressor 1 in a zero liquid state, the third on-off valve 9 opens after recovering the refrigerant, so the above problem is solved. The compressor 1 is not in a liquid compression state, and the third on-off valve 9
By opening, the pressure difference between the high-pressure side and the low-pressure side of the compressor 1 becomes even smaller than when no refrigerant flows through the pressure reducing mechanism, thereby reducing the electrical input.

In this embodiment, the specific electric circuit includes a timer circuit that operates for a certain period of time when the start switch of refrigerant heating operation is turned on, and a timer circuit that operates for a certain period of time when the start switch of the refrigerant heating operation is turned on, and a timer circuit that closes the first, second, and third valleys during operation of this timer circuit. valve? , 8.9, etc., such as a combination circuit of relays that operate to close the circuits 8 and 9, which are conventionally well known, will not be described.

As is clear from the above embodiments, the method of refrigerant heating operation of an air conditioner according to the present invention includes a compressor 1, a four-way switching valve 2, an indoor heat exchanger 3, a pressure reducing mechanism 4, an outdoor heat exchanger 5
, a refrigerant heater 6 for heating refrigerant, and a first on-off valve γ are connected to a circuit whose one end is connected between the indoor heat exchanger 3 and the pressure reduction mechanism 4 and the other end is connected to the suction side of the compressor 1. A second on-off valve 8 is connected between the pressure reducing mechanism 4 and the outdoor heat exchanger 5,
A third pipe bypasses the high pressure side piping and low pressure side piping of compressor 1.
A refrigeration cycle is constructed by connecting a check valve 10 that allows refrigerant to flow to the suction side of the compressor 1 between the on-off valve 9 of the heating cycle and the outlet of the four-way switching valve 2 in the heating cycle and the suction side of the compressor 1. When starting a refrigerant heating operation using a refrigeration cycle, the compressor 1 is started, and the first, second,
The third on-off valves 7, 8.9 are closed, and a refrigerant extraction operation is performed in which the refrigerant accumulated in the indoor heat exchanger 5, etc. is recovered to the compressor 1 and the indoor heat exchanger 3 for a certain period of time. By opening the third on-off valve 9 after the certain period of time has elapsed, it is possible to secure an amount of refrigerant that provides a predetermined heating capacity during the refrigeration cycle and to prevent local temperature rises of the refrigerant. It also has various advantages, such as reducing the electrical input to the compressor and not causing liquid compression, so that valves and the like inside the compressor will not be damaged.

BRIEF DESCRIPTION OF THE DRAWINGS The figure is a refrigeration cycle diagram of an air conditioner equipped with an operation control method according to an embodiment of the present invention. 1... Compressor, 2... Four-way switching valve, 3
... Indoor heat exchanger, 4 ... Pressure reduction mechanism, 5 ... Indoor 1 side heat exchanger, 6 ... Refrigerant heater, 1. ...First on-off valve, 8...
Second on-off valve, 9...Third on-off valve, 10...
·non-return valve.

Claims (1)

[Claims] 1 A compressor 1, a four-way switching valve 2, an indoor heat exchanger 3, a pressure reducing mechanism 4, an outdoor heat exchanger 5, one end of which is connected between the indoor heat exchanger 3 and the pressure reducing mechanism 4, and the other end of which is connected between the indoor heat exchanger 3 and the pressure reducing mechanism 4. a refrigerant heater 6 for heating refrigerant in a circuit connected to the suction side of the compressor 1;
, a first on-off valve γ, a second on-off valve 8 between the pressure reducing mechanism 4 and the outdoor heat exchanger 5, and a second on-off valve 8 that bypasses the high pressure side piping and the low pressure side piping of the compressor 1. A check valve 10 that allows refrigerant to flow to the suction side of the compressor 1 is connected between the on-off valve 9 of No. 3 and the outlet of the four-way switching valve 2 in the heating cycle and the suction side of the compressor 1. When starting a refrigerant heating operation using the refrigeration cycle, the compressor 1 is started, the 11th second and third on-off valves 7 and 8.9 are closed, and the chamber is closed. A refrigerant extraction operation is performed to recover the refrigerant accumulated in the outside heat exchanger 5 etc. to the compressor 1 and the indoor heat exchanger 3 for a certain period of time, and after the certain period of time has elapsed, the third on-off valve is opened. A refrigerant heating operation control method for an air conditioner in which 9 is opened.