JPS5986873A - Method of controlling operation of 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 refrigerant removal control during 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. It is something.

Conventional configuration and 4 problems In general, in this type of air conditioner, when refrigerant is passed through the outdoor heat exchanger during refrigerant heating operation, heat is radiated due to the effects of wind and outside temperature, reducing the heating capacity and reducing outdoor heat. There are drawbacks such as the inability to stabilize the refrigeration cycle because refrigerant and oil accumulate in the exchanger. Therefore, the refrigerant is not passed through the outdoor heat exchanger, and the refrigerant and oil accumulated in the outdoor heat exchanger are removed for a certain period of time at the start of refrigerant heating operation and stored in the indoor heat exchanger. Refrigerant removal control is performed to stabilize the refrigeration cycle by keeping the amount constant.

Conventionally, refrigerant bleeding control was performed only at the start of refrigerant heating operation, but as the operation time becomes longer, refrigerant and oil gradually drain from the valve that prevents refrigerant from flowing to the outdoor heat exchanger. The amount of refrigerant and oil in the refrigeration cycle gradually decreases, causing the compressor to malfunction.

In addition, one way to detect signs of abnormality in such a compressor is to detect the temperature and pressure during the refrigeration cycle and drain the refrigerant again. The refrigerant and oil in the outdoor heat exchanger were directly drawn out without passing any refrigerant or oil through the cycle. However, this method has the disadvantage that although the refrigerant can be removed, it is difficult to remove the oil. This was because the oil had been accumulated in the outdoor heat exchanger for a long time, and the temperature of the oil became low, causing poor viscosity and making it difficult to drain the oil.

If the refrigeration cycle continues to operate with oil remaining in the outdoor heat exchanger, the sliding parts of the compressor will wear out and seize may occur, making it impossible to continue operating the refrigeration cycle. there were.

Purpose of the Invention The present invention solves the above-mentioned problems of the prior art.It maintains an appropriate amount of circulating refrigerant in the refrigeration cycle, and also prevents oil from returning to the compressor, causing wear or burnout of the sliding parts of the compressor. This was done to prevent this from happening.

Components of the Invention The non-inventive feature is that during refrigerant heating operation, refrigerant and oil are forced to flow intermittently into the outdoor heat exchanger, and the refrigerant and oil accumulated in the outdoor heat exchanger are circulated through the refrigeration cycle. Teisawa refrigerant and oil are mixed to achieve compatibility, and then refrigerant removal control in the outdoor heat exchanger is performed.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

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 a check valve that passes refrigerant during cooling, 6 is an indoor heat exchanger, and 7 is a check valve. , 8 is an on-off valve that changes the flow of refrigerant during refrigerant heating operation and cooling operation; 9 is a vaporizing refrigerant heater that heats the return pipe to the compressor 1; There is a heat medium 9a such as water and a heating device for heating the heat medium 9a. In this heating device, 15 is a combustion fan, 16 is a rotating plate, 17,
is a motor interlocked with the combustion fan 15 and the rotating plate 16. 18 is a pipe provided to spray liquid fuel onto the rotating plate 16; 19 is an on-off valve that controls the supply of liquid fuel flowing through the pipe 18; 20 is a heater; 21 is a spark plug; 22 is an exhaust port. 10
is an on-off valve that connects the discharge side and suction side of the compressor 1.

11 and 12 are an indoor blower and an outdoor blower, respectively.

23 is a temperature detection device provided in a part of the evaporative refrigerant heater. A refrigeration cycle is constructed by connecting these in a ring as shown in the figure. Here 2
4 is a compressor 1, an indoor blower 11, an outdoor blower 12, a four-way switching valve 2, an on-off valve 8, 10, 19, a combustion fan 17,
This is a control device for controlling the spark plug 21 and the heater 20, which are connected to each other by relays as shown in FIG. 2. That is, the compressor 1, the four-way switching valve 2, the on-off valves 8 and 1o, the indoor blower 11, the outdoor blower 12, and the motor 1.
7. The on-off valve 19, heater 20, and spark plug 21 are relay contacts IL and 21L, respectively.

8a, 10a, 11a, 12&, 17a, 19a.

2C)a, 212L are connected in series, and these series circuits are connected in parallel with each other.

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 6, and the check valve 5.
, pressure reducer 4, indoor heat exchanger 3, four-way switching valve 2, check valve 7
This constitutes a refrigeration cycle in which the air passes through the air and returns to the compressor 1.

Next, when performing a refrigerant heating operation using the vaporization type refrigerant heater 9, the refrigerant flows into the compressor 1, the four-way switching valve 2, the indoor heat exchanger 3, the on-off valve 8, and the vaporization type refrigerant heater 9. Two cycles are constructed: a refrigeration cycle that returns to the compressor 1, and a refrigeration cycle that returns from the compressor 1 to the compressor 1 through the on-off valve 10. However, in the case of refrigerant heating operation, the refrigerant does not pass through the outdoor heat exchanger 6 due to the check valves 5 and 7. Further, at the same time as the refrigerant heating operation, the heater 2o section is energized until the temperature rises to a certain level or higher.

Here, the refrigerant is heated using the vaporizing refrigerant heater 9. By first closing the on-off valves 8 and 10 for a certain period of time, the refrigerant accumulated in the outdoor heat exchanger 6 is removed by the four-way switching valve 2, the check valve 7. After passing through the compressor 1, the four-way switching valve 2, and the indoor heat exchanger 3, the refrigerant does not flow any further due to the on-off valve 8 and the check valve 5, but eventually accumulates inside the indoor heat exchanger 3. Further, the refrigerant that had accumulated in the vaporization type refrigerant heater 9 also accumulates inside the indoor heat exchanger 3. After this refrigerant removal control is completed, the motor 17 is operated to rotate the combustion fan 15 and the rotary plate 16, and at the same time, the on-off valve 19 is opened and liquid fuel is supplied from the pipe 18 to the rotary plate 16.
When the water is stirred and becomes a mist, heater 2 is turned on.
It is vaporized by o and ignited by the spark plug 21.

Normally, when the refrigerant heating operation time is short, by performing refrigerant removal control at the start of operation, it is possible to prevent abnormalities from occurring in the refrigeration cycle operation.

However, as the refrigerant heating operation time becomes longer, the refrigerant and oil gradually flow into the outdoor heat exchanger 6 through the check valves 5 and 7 that prevent the refrigerant and oil from flowing into the outdoor heat exchanger 6, causing the refrigeration cycle to deteriorate. The refrigerant and oil circulating inside will become insufficient.

The control device 24 closes the on-off valve 1° and switches the four-way switching valve 2 at every first set time (approximately 2 hours) from the start of the refrigerant heating operation. This allows the refrigerant to be transferred to the compressor 1. Four-way switching valve2. Outdoor heat exchanger 6° check valve 5. After passing through the pressure reducing mechanism 4, it is divided into two parts, one of which has an on-off valve 8. The refrigerant passes through the evaporative refrigerant heater 9 and returns to the compressor 1, and the other end returns to the indoor heat exchanger 3. Four-way switching valve2. Two refrigeration cycles are constructed in which the check valve 7 returns to the energized compressor 1.

As a result, the low-temperature refrigerant and oil that had accumulated in the outdoor heat exchanger 6 are mixed with the refrigerant and oil that were circulating during the refrigerant heating operation, and the refrigerant and oil are stabilized and the viscosity of the oil is reduced. The condition will improve. This state is controlled by the control device 24 for a second set time (
1 minute), the on-off valves 8 and 10 are closed, the four-way switching valve 2 is switched to the refrigerant heating operation cycle, and the refrigerant and oil in the outdoor heat exchanger 6 are transferred to the indoor heat exchanger 3.
Controls the removal of refrigerant stored in the tank, and then continues refrigerant heating operation.

In this way, the control device 24 switches the refrigeration cycle to flow the refrigerant and oil into the outdoor heat exchanger 6 for a short time and then controls the refrigerant removal at regular intervals from the start of the refrigerant heating operation. The refrigerant and oil accumulated in the heat exchanger 6 are smoothly recovered during the refrigeration cycle of the refrigerant heating operation, and stable refrigeration cycle operation can be continued.

Effects of the Invention The air conditioner operation control method of the present invention connects a compressor, a switching valve, an indoor heat exchanger, a pressure reducing device, a check valve, an outdoor heat exchanger, and a refrigerant heater that heats a refrigerant. During the refrigerant heating operation of the refrigeration cycle, the refrigerant is forced to flow into the outdoor heat exchanger intermittently, and then the refrigerant and oil accumulated in the outdoor heat exchanger are recovered into the refrigeration cycle, thereby reducing the outdoor heat. The refrigerant and oil accumulated in the exchanger are smoothly recovered, and in particular, the oil is recovered in a short time by being mixed with the oil in the refrigeration cycle during the refrigerant heating operation. Therefore, since the amount of oil inside the compressor is ensured, the wear of the sliding parts is reduced, the burnout of the motor coil can be prevented, a stable refrigeration cycle can be obtained, and furthermore, the refrigerant can be refrigerated in a short time. As the oil is recovered, the heat radiation from the indoor heat exchanger only needs to drop for a short period of time, so that the room temperature does not drop and the heating feeling is not impaired.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle diagram of an air conditioner controlled by a heating operation control method according to an embodiment of the present invention, and FIG. 2 is a partial electrical circuit diagram of the air conditioner. 1...Compressor, 2...-Four-way switching valve, 3
... Indoor heat exchanger, 4 ... Pressure reducer, 5
...Check valve, 6...Outdoor heat exchanger, 7
... Check valve, 9 ... Evaporative refrigerant heater.

Claims (1)

[Claims] During a refrigerant heating operation of a refrigeration cycle that connects a compressor, a switching valve, an indoor heat exchanger, a pressure reducing device, a check valve, an outdoor heat exchanger, and a refrigerant heater that heats the refrigerant, the outdoor heat exchanger is intermittently A method for controlling the operation of an air conditioner, in which the refrigerant is forced to flow into the outdoor heat exchanger, and the refrigerant and oil accumulated in the outdoor heat exchanger are then recovered in the refrigeration cycle.