JPH0233100Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a refrigerant control circuit in a heat pump type air conditioner.

Conventional configuration and its problems Traditionally, multi-room separate air conditioners have been configured as shown in Figure 1. During cooling, the circuit indicated by the solid line arrow is used, and during heating, the refrigerant is supplied to the circuit indicated by the dotted line arrow. is circulated.
In order to cope with overload operation during heating operation, a bypass pipe 3 is provided branching from the branch point 2 of the discharge pipe 1, and a solenoid valve 4 is provided in this bypass pipe 3.
At the same time, a portion extending from the bypass pipe 3 is combined below the outdoor heat exchanger 5 to form a heat exchange section 6, and this heat exchange section 6 is connected to a liquid receiver 8 via a check valve 7. are doing.

If an overload operation occurs during heating, the solenoid valve 4 is opened, and a part of the refrigerant in the discharge pipe 1 passes through the bypass pipe 3 and is condensed in the heat exchange section 6, and the condensed refrigerant passes through the check valve 7. The liquid flows through the liquid receiver 8 and bypasses the indoor units 9 and 10, thereby lowering the high pressure. And capillary tubes 11 and 12
It joins the refrigerant flowing through the liquid receiver 8 and circulates through the electric expansion valve 13 and the outdoor heat exchanger 5.

In such a conventional circuit, the refrigerant that has flowed through the capillary tubes 11 and 12 on the main circuit side and the refrigerant that has flowed through the heat exchange section 6 when the solenoid valve 4 is opened due to high load. The refrigerant is in the liquid receiver 8.
The flow rate of the refrigerant increases, and since both are high-pressure refrigerants, the refrigerant on the main circuit side (capillary tubes 11 and 12 side) is mixed with the high-pressure refrigerant flowing from the heat exchange section 6. As a result, the refrigerant becomes blocked and becomes difficult to flow in the direction of the electric expansion valve 13 and outdoor heat exchanger 5, which impedes the flow rate of refrigerant in the main circuit and causes operations such as operation without sufficient heating performance. It had drawbacks.

Purpose of the invention This invention solves the above-mentioned drawbacks of the conventional technology. Even if the solenoid valve of the bypass pipe opens during overload (heating), the main circuit still maintains the flow rate, resulting in a stable heat pump cycle. With the goal.

Structure of the invention In order to achieve the above object, the invention provides a solenoid valve that opens in the event of an overload in a bypass pipe branched from a discharge pipe, and a solenoid valve that is installed through a part of an outdoor heat exchanger from this bypass pipe. a heat exchange section;
A check valve that passes to the liquid receiver side, a pressure reducing mechanism that lowers the pressure, and the liquid receiver are connected in sequence, and the refrigerant pressure to be bypassed is reduced and sent to the liquid receiver from the bypass pipe. be.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described based on FIG. 2. In the figure, 20 is a rotary compressor, and its discharger 51 connects a four-way valve 21, an outdoor heat exchanger 22, an electric expansion valve 23, a liquid receiver 24, a main pipe 30, and a capillary tube for the No. 1 indoor unit. 2
9, the No. 1 liquid side solenoid valve 25, and the No. 1 indoor unit 26 are connected in this order. Further, branching from the main flow pipe 30, a capillary tube 31 for a No. 2 indoor unit, a No. 2 liquid side solenoid valve 27, and a No. 2 indoor unit 28 are connected in sequence. Said No. 1 indoor unit 26 and No. 2 indoor unit 28
are connected to the compressor 20 via a gas-side solenoid valve 32, a gas-side solenoid valve 33, a four-way valve 21, a suction pipe 53, and an accumulator 34, respectively.

An injection exit circuit 35 for cooling is connected to the outlet of the outdoor heat exchanger 22 during cooling and an injection exit port 36 of the compressor 20, and a check valve 37 and a capillary tube 38 are connected to this circuit. It is set up. In addition, the No. 1 indoor unit 26 and the compressor 20
An injection exit circuit 39 for heating is connected to the injection exit port 36 of the heating system, and this circuit is provided with check valves 40, 41 and capillary tubes 42, 43. In addition, No. 1 indoor unit 26
Between the No. 2 indoor unit 28 and the outdoor heat exchanger 22, pressure equalizing pipes 44 and 45 are provided to recover high-pressure refrigerant from the stopped indoor unit during heating, and this circuit includes a check valve 46. , 47 and capillary tubes 48, 49.

A bypass pipe 54 is branched from the discharge pipe 51 of the compressor 20, and is connected to a part of the outdoor heat exchanger 22 via a solenoid valve 55 that opens when the discharge pressure becomes overloaded. A heat exchange section 56 is constructed in which the refrigerant is passed through and condensed. The high-pressure condensed refrigerant condensed in the heat exchange part 56 is then connected to the receiver 24 via a check valve 57 that passes the condensed refrigerant condensed in the heat exchange part 56 and a capillary tube 58 of the pressure reduction mechanism. After reducing the pressure, the liquid receiver 24
I am trying to send it to. In addition, 50 in the figure is a high pressure sensor that detects the refrigerant discharge pressure of the discharge pipe 51, and 52 is a low pressure sensor that detects the refrigerant suction pressure of the suction pipe 52.

A solid line arrow indicates a refrigerant circuit during cooling, and a dotted line arrow indicates a refrigerant circuit during heating.

In the above configuration, during normal operation, the compressor 20, four-way valve 21, outdoor heat exchanger 22, electric expansion valve 23, liquid receiver 24, main pipe 30, capillary tubes 29, 31, liquid side electromagnetic valves 25, 27,
Each indoor unit 26, 28, gas side solenoid valve 32, 33,
It is circulated through the four-way valve 21 and the storage unit 34.

In addition, during normal operation, during heating, the compressor 20, four-way valve 21, gas side solenoid valves 32, 33, each indoor unit 2
6, 28, liquid side solenoid valves 25, 27, capillary tubes 29, 31, main flow pipe 30, liquid receiver 24, electric expansion valve 23, outdoor heat exchanger 22, four-way valve 21,
It is circulated with the storage unit 34.

Thus, in the former case of cooling, the temperature of the windings of the compressor 20 is high because the outside air temperature is high, but the heat exchange in the outdoor heat exchanger 22 is high, so the discharge pipe 5
The refrigerant pressure at 1 is unlikely to result in overload operation. However, in the latter case during heating, the heat exchange in each indoor unit 26, 28 is reduced, and the suction pipe 5
3 becomes high, and therefore the pressure of the discharge pipe 51 often becomes high as well. When the pressure in the discharge pipe 51 increases and reaches a predetermined pressure or higher, the solenoid valve 55 opens, and a part of the refrigerant flows from the discharge pipe 51 to the bypass pipe 54 and is condensed in the heat exchange section 56. It passes through a check valve 57 and a capillary tube 58, which is a pressure reducing mechanism, where the pressure is reduced. The depressurized refrigerant flows to the receiver 24 . In this liquid receiver 24, the capillary tube 29,
31 and joins with the mainstream refrigerant flowing through the main flow pipe 30, but since the refrigerant on the main flow pipe 30 side is a high-pressure refrigerant, this main flow refrigerant mainly flows through the electric expansion valve 23.
Due to the low-pressure refrigerant flowing to the side and flowing through the capillary tube 58 of the bypass pipe 54, it is less likely that the flow of the mainstream refrigerant will be blocked.

Therefore, the liquid refrigerant rarely accumulates in the liquid receiver 24 in excess of a predetermined amount, and heating can be continued in a stable heat pump cycle.

The capillary tubes 29 and 31 are designed to reduce the amount of pressure reduction during heating.

Effects of the invention As is clear from the above description of the embodiments, the present invention has a bypass pipe branched from the discharge pipe of the compressor.
A solenoid valve that opens during overload operation, a heat exchange section provided through a part of the outdoor heat exchanger, and a heat exchange section located between this heat exchange section and the liquid receiver and connected to the liquid receiver side. A check valve and a pressure reducing mechanism such as a capillary tube are provided, and the refrigerant to be bypassed is sent to the liquid receiver from the bypass pipe under reduced pressure.
The refrigerant flowing through the main pipe is not blocked or made difficult to flow, and therefore, the refrigerant in excess of a predetermined amount does not accumulate in the liquid receiver. This allows stable operation of the heat pump cycle, especially during heating, and provides effects such as improved heating performance.

[Brief explanation of drawings]

FIG. 1 is a refrigerant circuit diagram of a heat pump type air conditioner to be explained in the related art, and FIG. 2 is a refrigerant circuit diagram of a heat pump type air conditioner according to an embodiment of the present invention. 20... Compressor, 21... Four-way valve, 22... Outdoor heat exchanger, 23... Electric expansion valve, 24... Liquid receiver, 25, 27... Liquid side solenoid valve, 26, 28...
Indoor unit, 29, 31, 42, 43... Capillary tube, 40, 41, 57... Check valve, 51...
...Discharge pipe, 54...Bypass pipe, 56...Heat exchange section.

Claims (1)

[Scope of utility model registration request] In a heat pump refrigeration cycle in which a compressor, a four-way valve, an outdoor heat exchanger, an electric expansion valve, a liquid receiver, a capillary tube for an indoor unit, and a liquid-side solenoid valve are connected, A bypass pipe branched from the discharge pipe and connected to the liquid receiver is provided, and the bypass pipe includes a solenoid valve that opens during overload operation, and a part of the bypass pipe passes through a part of the outdoor heat exchanger. A heat exchange section, a check valve located between the heat exchange section and the liquid receiver and open to the liquid receiver side, and a pressure reducing mechanism such as a capillary tube are provided. A refrigerant control device for a heat pump type air conditioner, wherein a refrigerant to be bypassed is sent to the liquid receiver from the bypass pipe under reduced pressure.