JPS6056980B2 - refrigeration cycle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a refrigeration cycle for an air conditioner, a refrigeration device, etc.

Figure 1 is a refrigerant system diagram of a conventional air conditioner, where 1 is a compressor, 2 is a condenser, 3 is an expansion valve, 4 is an evaporator, and 5 is a refrigerant system diagram.
1 is a prime mover for driving the compressor, 6 is an intermediate port of the condenser 2, 7 is a heat exchanger, 8 is a valve, 9 is a throttle, and 10 is a confluence point.

During normal operation, refrigerant flows through the compressor 1, condenser 2, expansion valve 3, evaporator 4, and compressor 1 in this order. When it is desired to reduce the cooling capacity due to a drop in the indoor temperature, that is, when controlling the capacity, a part of the refrigerant is bypassed from the intermediate port 6 of the condenser 2, and the air is transferred to the primary side of the heat exchanger 7, the valve 8, and the throttle 9.
, the refrigerant passes through the secondary side of the heat exchanger 7 , joins with the refrigerant from the evaporator 4 at the merging point 10 , and returns to the compressor 1 . At this time, the amount of refrigerant flowing through the condenser 2 and the expansion valve 3 to the evaporator 4 decreases, and the cooling capacity of the evaporator 4 decreases.

In the conventional device described above, depending on the room temperature, the refrigerant leaving the secondary side of the heat exchanger 7 will be in a gas-liquid mixed state, and if the room temperature is low and the cooling load is small, the evaporator 4
The refrigerant flowing through becomes a gas with a low degree of heating.

Therefore, the refrigerant mixed at the confluence point 10 may become a gas-liquid mixture, and when this refrigerant is sucked into the compressor 1, liquid compression occurs inside the compressor 1, which can cause damage to the compressor 1. . For this reason, capacity control was only possible under limited operating conditions. In view of the above, the present invention prevents liquid compression inside the compressor during capacity control, and enables capacity control to be performed over a wide range and smoothly. One embodiment of the present invention will be specifically described. In FIG. 2, numerals 1 to 10 are the same as those in FIG.

101 is a gas-liquid separator for separating the refrigerant from the secondary side of the heat exchanger 7, 102 is a throttle for flowing the separated liquid refrigerant to the evaporator 4, and 103 is a gas-liquid separated refrigerant. The gas refrigerant is throttled to flow into the compressor 1.

The refrigerant extracted from the intermediate boat 6 of the condenser 2 passes through the primary side of the heat exchanger 7, the valve 8, and the throttle 9, returns to the secondary side of the heat exchanger 7, and then enters the gas-liquid separator 101. .

The liquid refrigerant separated here flows to the evaporator 4 through the throttle 102, and the gas refrigerant passes through the throttle 103 and mixes with the refrigerant that has flowed through the evaporator 4 at a flow point 10, and is sucked into the compressor 1. When the capacity is not controlled, the gas discharged from the compressor 1 passes through the condenser 2 and the expansion valve 3 and returns to the compressor 1 from the evaporator 4.

When the indoor temperature becomes low and it is desired to lower the cooling capacity, that is, to control the capacity, the valve 8 is opened and the refrigerant in a gas-liquid mixed state is guided from the intermediate boat 6 of the condenser 2 to the primary side of the heat exchanger 7. This refrigerant passes through a valve 8 and a restrictor 9 into a heat exchanger 7.
is again guided to the secondary side of At this time, since the pressure is throttled by the throttle 9, the temperature of the refrigerant decreases. Because the primary side refrigerant is cooled by this low temperature secondary side refrigerant, 1
The temperature on the next side becomes lower. The refrigerant in a gas-liquid mixed state discharged from the secondary side of the heat exchanger 7 is separated into gas-liquid by a gas-liquid separator 101. Of the refrigerant separated into gas and liquid, the liquid refrigerant is guided to the evaporator 4 through the throttle 102 . On the other hand, the remainder of the refrigerant in the condenser 2 passes through an expansion valve 3 to an evaporator 4. be led to. Therefore, the amount of refrigerant flowing through the evaporator 4 is the sum of the refrigerant passing through the gas-liquid separator 101, the throttle 102, and the refrigerant passing through the expansion valve 22, but the capacity is not controlled by the amount of gas refrigerant separated by the gas-liquid separator 101. This will reduce the indoor cooling capacity. On the other hand, the capacitor intermediate boat 6
Since the flow rate of the later condenser 2 is smaller, the cooling effect of the condenser 2 is improved and the refrigerant temperature of the condenser 2 is lowered overall.At the same time, the temperature of the refrigerant that has passed through the heat exchanger 7 is also lowered, and the Since the discharge pressure of compressor 1 corresponds to the refrigerant condensation temperature, the discharge pressure of compressor 1 becomes low.

Note that the suction pressure of the compressor 1 at this time does not change significantly, so the compression ratio of the compressor 1 becomes small, and the compressor 1
The power of the prime mover 5 that drives the motor 5 also becomes smaller. Thus, as the indoor cooling load decreases, the power of the compressor 1 also decreases. In the above explanation, the diaphragm 102 was a fixed diaphragm, but by making it a variable diaphragm, detecting the room temperature and controlling the degree of diaphragm 102 based on this signal, the amount of refrigerant flowing to the evaporator 4 can be adjusted. , room temperature can be controlled smoothly. If the indoor temperature is adjusted by controlling the compressor 1 to 0N-OFF, the indoor temperature will change greatly, but if the cooling capacity is controlled by changing the refrigerant flow rate to the evaporator 4 as in the present invention, the indoor temperature will change. can be kept constant with high precision. At this time, the power of the compressor 1 also decreases, and its coefficient of performance does not decrease significantly, and the action of the gas-liquid separator 101 prevents the compressor 1 from compressing the liquid. Damage can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a refrigerant system diagram of a conventional air conditioner, and FIG. 2 is a refrigerant system diagram showing one embodiment of the present invention.

Claims (1)

[Claims] 1. In a refrigeration cycle equipped with a bypass system in which the refrigerant extracted from the intermediate port of the condenser is returned through the primary side of the heat exchanger, a control valve, and a throttle, to the secondary side of the heat exchanger, and then to the compressor. A refrigeration cycle characterized in that a gas-liquid separator is provided downstream of a heat exchanger in a bypass system, and the refrigerant gas separated there flows into a compressor and the liquid refrigerant flows into an inlet of an evaporator.