KR100593719B1 - Cooling cycle - Google Patents

Abstract

The present invention relates to a cooling cycle that allows only gas refrigerant to enter the compressor from the evaporator and can buffer against external disturbances.

A cooling cycle in which a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected, the cooling cycle comprising: a body for separating a gas refrigerant and a liquid refrigerant from the gas-liquid mixed refrigerant discharged from the evaporator with a space for storing a constant amount of refrigerant; And refrigerant inlet means for connecting the evaporator outlet pipe to one side of the body and for connecting the compressor suction pipe to the other side, wherein the refrigerant inlet means has an inlet pipe extending from the bottom of the body to a predetermined length. The outlet pipe further includes a baffle with the tip end of the body being at least close to the ceiling surface from the top surface of the body, and moreover a plurality of fine balls formed in the thickness direction above the tip end of the inlet pipe.

In the cooling cycle of the present invention, a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected to each other, and a phase separation means for separating gas refrigerant and liquid refrigerant from the outlet pipe of the evaporator and sending only the gas refrigerant to the compressor is provided. Buffer against disturbances.

Description

Cooling cycle {A refrigerant cycle}

1 is a configuration of a cooling cycle according to an embodiment of the present invention,

Figure 2 is a longitudinal cross-sectional view showing a phase separator of the present invention,

Figure 3 is a longitudinal cross-sectional view of a phase separator showing another embodiment of the present invention,

Figure 4 is a graph for explaining the evaporator outlet superheat,

5 is a configuration diagram of a conventional cooling cycle.

* Description of the symbols for the main parts of the drawings *

1; cooling cycle 10; phase separator

11; body 12, 13; cap

14, outlet pipe 15; inlet pipe

16; baffles

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an evaporator of a cooling system used in a vehicle air conditioner, and more particularly, to a cooling cycle for preventing liquid refrigerant from entering a compressor by separating a refrigerant at an outlet side of an evaporator.

5 is an explanatory diagram showing a configuration of a cooling cycle of a general air conditioner. The cooling cycle in which the entirety is denoted by reference numeral 30 indicates the passage amount of the compressor 31, the condenser 32, the receiver 33 containing the liquefied refrigerant in the condenser 32, and the amount of passage of the liquid refrigerant. It is provided with an expansion valve 34 and an evaporator 35 to adjust.

The expansion valve 34 has a thermostat 36 for detecting the refrigerant temperature of the outlet side of the evaporator 35, and a pressure reducing tube 37 of the diaphragm of the expansion valve 34. 34) and adjust the valve opening amount. 38 is also the piping for the refrigeration system.

The evaporator absorbs external heat and causes the refrigerant to turn into a gaseous state. An expansion valve is used to control this. The expansion valve detects the state of the evaporator outlet refrigerant by the temperature reduction tube and the pressure reducing tube to control the refrigerant flow rate by the valve operation and to regulate the evaporator outlet superheat constant.

However, in the conventional air conditioner system, since the pipe is connected from the evaporator outlet to the thermostat tube of the expansion valve and the disturbance due to the heat load and the operating state of the system is transmitted directly to the expansion valve thermostat, liquid refrigerant flows from the evaporator intermittently and expands. The control function is disturbed, and the instability of the refrigerant control due to the heat load fluctuation is transmitted to the expansion valve temperature reduction amplification.

Accordingly, the condition of the evaporator is sensitive to the operating state of the system, so the hunting phenomenon in which the temperature and the pressure are severely changed is likely to occur, and the cooling performance may be deteriorated.

The present invention is to solve the above problems, to provide a cooling cycle that allows only the gas refrigerant from the evaporator to the compressor to be introduced and buffer against external disturbances.

In order to achieve the above object, the phase separator of the present invention has a space for storing a constant amount of refrigerant in a cooling cycle in which a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected, and a gas refrigerant and a liquid from a gas-liquid mixed refrigerant discharged from the evaporator. A body for separating the refrigerant; And refrigerant inlet / outlet means for connecting the evaporator outlet pipe to one side of the body and for connecting the compressor suction pipe to the other side.

According to a first embodiment of the refrigerant inlet and outlet means, the inlet pipe is discharged from the bottom of the body into a predetermined length, and the outlet pipe is discharged from the upper surface of the body so that the tip is at least close to the ceiling surface. It further includes a baffle formed with a plurality of fine balls in the thickness direction above the distal end portion.

According to a second embodiment of the refrigerant inlet and outlet means, the outlet pipe is discharged from the bottom of the body to the inside of the front end to be close to the ceiling surface, and the inlet pipe is led to the inside of the body by a predetermined length. Preferably, a plurality of oil holes are formed in the circumferential direction of the outlet pipe in a portion proximate to the same.

In addition, the cooling cycle of the present invention is that a compressor, a condenser, an expansion valve and an evaporator are sequentially connected, and the phase separation means for separating the gas refrigerant and the liquid refrigerant in the outlet pipe of the evaporator and sending only the gas refrigerant to the compressor is installed. It is characterized by.

According to this configuration, liquid refrigerant may be mixed in the refrigerant flowing from the evaporator to the compressor, and such gas-liquid mixed refrigerant may be separated by its own weight in the phase separator and only the gaseous refrigerant may be introduced into the compressor. Disruption of the expansion valve, which occurs when the liquid refrigerant leaks, can be prevented.

In addition, by detecting the temperature and pressure of the air coolant flowing through the evaporator outlet side, it is possible to prevent the phenomenon of severe fluctuations in the temperature and pressure of the system to prevent the deterioration of cooling performance.

1 is a block diagram showing a cooling cycle of the present invention. The cooling cycle of the present invention, which is denoted by the entirety of the present invention, has the same basic construction requirements as the conventional cooling cycle, except that a phase separator is provided in the outlet pipe of the evaporator.

The cooling cycle 1 includes a compressor 2, a condenser 3, a receiver 4, a mechanical expansion valve 5 having a thermostat 8 for detecting a refrigerant temperature, a pressure reducing tube 9 and a diaphragm, and an evaporator ( 6) is sequentially connected by the pipe (7) to circulate the refrigerant. Furthermore, the present invention includes a phase separator 10 installed in the evaporator outlet pipe.

After separating the gas refrigerant and the liquid refrigerant from the gas-liquid mixed refrigerant discharged from the evaporator (6), the phase separator 10 for sending only the gas refrigerant to the compressor between the evaporator 6 and the thermostat (8) Is installed on.
The expansion valve (5) detects the temperature and pressure of the evaporator outlet refrigerant by the thermostat (8) and the decompression tube (9) for detecting the state of the outlet refrigerant of the evaporator (6), that is, the refrigerant temperature. To control the evaporator (6) outlet superheat constant.

2 and 3 show a phase separator. Referring to FIG. 2, the phase separator 10 has an upper and lower parts of the cylindrical body 11 and the upper and lower parts thereof are sealed with caps 12 and 13, and an outlet pipe 14 connected to the suction side of the compressor 2 to the upper cap 12. And the inlet pipe 15 connected to the outlet side of the evaporator 6 through the lower cap 13, and the front end portions of the inlet and outlet pipes 14 and 15 are introduced into the body 11.

The inlet pipe 15 is protruded from the bottom surface of the lower cap 13 into a predetermined length, and the outlet pipe 14 is protruded at least from the ceiling surface of the upper cap 12.

By installing a baffle 16 at the center of the body 11, gaseous refrigerant from the gas-liquid mixed refrigerant flowing from the evaporator 6 passes through the baffle 16 and flows through the outlet pipe 14 toward the compressor 2. In addition, the liquid refrigerant collides with the baffle 16 and falls downward to be stored. The liquid refrigerant stored in the body 11 is gradually evaporated by heat transfer from the outside and flows into the compressor 2 in a gaseous state.

Referring to FIG. 3, the phase separator 20 has a body 21 of a cylindrical body whose upper and lower parts are sealed, and upper and lower parts of the body 21 are sealed by caps 22 and 23. An inlet pipe 24 connected to the outlet side of the evaporator 6 penetrates through the outer circumferential surface of the body 21 and exits therein, and an outlet pipe 25 connected to the inlet side of the compressor 2 penetrates therethrough. The distal end portion is allowed to exit into the body 21. The tip end portion of the outlet pipe 25 extends above the inside of the body 21 to prevent liquid refrigerant from entering.

Furthermore, an oil circulation hole 26 is formed in the lower region of the outlet pipe 25 with respect to the outlet pipe 25 introduced into the body 21 in all directions so that the oil contained in the refrigerant is combined with the gaseous refrigerant. Reduce to (2).

The phase separator 10 according to the embodiment affects the amount of refrigerant passing through the expansion valve 5, and expands accurate information on the temperature and pressure detection of the refrigerant flowing through the outlet pipe of the evaporator 6. The air conditioner system can be stabilized by transmitting to the valve 5.

The phase separator 10 has a small evaporator outlet superheat so that when the liquid refrigerant is discharged, the flow in the inlet pipe 15 of the phase separator 10 shows an annular flow or a laminar flow depending on the flow rate. In other words, when the flow rate is large, the liquid refrigerant flows out of the tube or when the flow rate is small, the effect of gravity is applied to flow the layered layer below the tube.

In the phase separator 10, the inlet pipe 15 and the outlet pipe 14 are separated by the baffle 16, and the liquid refrigerant is temporarily stored after falling down against the baffle 16. The stored liquid refrigerant is gradually evaporated by heat transfer from the outside of the phase separator to flow to the compressor (2).

The state of the outlet refrigerant of the evaporator 6 is controlled by the expansion valve 5, which detects the temperature of the outlet refrigerant of the evaporator 6 and corrects it according to the outlet pressure to compensate for the opening of the valve. Adjust When the temperature of the outlet refrigerant decreases, the valve opening is increased to increase the refrigerant flow rate, and when the temperature of the outlet refrigerant increases, the valve opening is reduced to reduce the refrigerant flow rate, resulting in constant overheating of the outlet refrigerant. It can be adjusted to have a degree.

In general, as the superheat degree of the evaporator outlet refrigerant decreases as shown in FIG. 4, the cooling capacity increases. However, when the superheat at the outlet of the evaporator is reduced, there are many disadvantages in that the system stability is reduced and adversely affects.

The smaller the evaporator outlet superheat, the greater the chance of liquid refrigerant flowing out. In general, when the superheat is very small, the calculation of the superheat by temperature and pressure measurement is meaningless. If the expansion valve thermostat or thermocouple measured the surface temperature in the localized area, the localized area containing a small amount of liquid refrigerant was measured, even if the superheat was 3 ° C in the temperature sensor.

Changes in small amounts of heat under normal superheat of 5 ° C or less cannot be measured by the temperature sensor, and the superheat is hardly affected by the heat absorbed by the small amount of liquid refrigerant. In addition, the expansion valve can not control the flow rate in the refrigerant saturation conditions. This is because there is no temperature change of the refrigerant in the saturation region. Therefore, it is possible to increase the stability of the system and increase the cooling capacity by controlling the expansion valve even if the refrigerant state at the evaporator outlet is close to the saturation state.

In the present invention, a phase separator or a buffer is installed between the evaporator outlet and the thermostat. Even though the evaporator outlet condition is controlled to be close to the saturation state, the refrigerant passing through the phase separator allows only the gaseous refrigerant to pass therethrough. The refrigerant after passing through the phase separator maintains a complete gas state to accurately detect the refrigerant state in the expansion valve thermostat.

In addition, if the system operates unstable and liquid coolant flows out of the evaporator outlet or the amount of liquid coolant changes significantly, the phase separator serves to buffer it.

As described in the above embodiments, the present invention installs a phase separator in the evaporator discharge line to separate the gas in the refrigerant discharged from the evaporator and the refrigerant in the liquid state by its own weight so that only the refrigerant in the gas state can flow into the compressor. In this case, the cooling capacity of the evaporator may be maximized by increasing the control force of the expansion valve that controls the amount of refrigerant flowing into the evaporator according to the temperature and pressure of the refrigerant passing through the evaporator discharge line.

Furthermore, it is possible to protect the compressor by preventing liquid refrigerant inflow, thereby improving control stability of the air conditioning system.

Claims (6)

delete delete delete delete delete A mechanical expansion valve having a compressor, a condenser, a diaphragm, and an evaporator are sequentially connected. A thermostat tube and a decompression tube of the mechanical expansion valve are installed at an outlet pipe of the evaporator to detect a temperature and pressure of the refrigerant. And a phase separation means for separating the gas refrigerant and the liquid refrigerant from the gas-liquid mixed refrigerant discharged from the air and then sending only the gas refrigerant to the compressor, between the evaporator and the thermostat.

Images