KR100395026B1 - An evaporative temperature compensation device and process of heat pump - Google Patents

Abstract

The present invention relates to an apparatus for compensating an evaporation temperature of a heat pump and a method of compensating the same. In a heat pump circulating a compressor, a four-way valve, a condenser, an expansion valve, an accumulator, and an evaporator, the upper part of the accumulator 50 and the compressor 10 Connect the flash line 71 via the evaporator 70 between two stages of suction side, and install a double-tubular manifold tube 71a close to the evaporator by different paths to the evaporator. Connect the manifold tube with the flash line and open the flash line when the temperature of the main refrigerant flowing through the tube of the evaporator drops below the set value during heating in winter. By preventing the flash refrigerant gas and the secondary expanded low-temperature, low-pressure main refrigerant gas to prevent heat paralysis and sexual formation of the evaporator, the main cooling after the heat exchange Is connected to the first stage suction side of the compressor to control the superheat degree of the first stage suction side of the compressor, and the flash refrigerant gas is supplied to the second stage suction side to improve the compression efficiency due to the increase in mass and specific volume of the compressed refrigerant. It is.

Description

An evaporative temperature compensation device and process of heat pump

The present invention relates to an apparatus for compensating an evaporation temperature of a heat pump and a method of compensating the same, and more particularly, a flash gas line connected between an accumulator and a second stage suction side of a compressor via an evaporator, and a tube of an evaporator in a winter heating cycle. When the temperature of the main refrigerant flowing under the temperature drops below the set value, the flash line is opened to exchange heat between the refrigerant refrigerant from the accumulator and the flash line and the main refrigerant flowing through the tube of the evaporator to prevent supercooling and freezing of the evaporator and to increase evaporation efficiency. In addition, by supplying the isostatic and reduced refrigerant gas of the flash line passing through the evaporator to the second stage suction side of the compressor, the compression efficiency is increased by increasing the mass and specific volume of the compressed refrigerant, and It contributes to suppressing overload and improving durability by controlling superheat, and ultimately, The present invention relates to an evaporation temperature compensating device for a heat pump and a method of compensating the same, by efficiently constructing a heating cycle without using the device, thereby significantly reducing an apparatus cost and an operating cost.

In general, the heat / cooling cycle of the heat pump is connected to one side of the four-way valve at the outlet of the compressor, the condenser is connected to the other side of the four-way valve, the expansion mechanism and the accumulator is connected to the condenser.

In addition, the expansion mechanism is connected to the evaporator, the evaporator is connected to the other side of the four-way valve.

This conventional heat pump cycle is used for cooling or heating by switching the flow of the four-way valve to the condenser and evaporator, that is, when the heat pump cycle is cooling, the indoor heat exchanger acts as an evaporator and is heating. In the case of a condenser, on the contrary, the outdoor heat exchanger acts as a condenser when cooling, and as an evaporator when heating.

During the heating cycle of the heat pump, the refrigerant flows in the order of compressor-four-way valve-condenser-expansion device-evaporator-four-way valve-compressor. In order to maintain the proper temperature of the discharged hot air, the refrigerant temperature of the condenser should be kept above a certain value higher than the room temperature, and the evaporation temperature of the outdoor unit (coolant temperature in the evaporator) is lower than the outdoor temperature within the set range. Must be maintained.

However, when the temperature of the refrigerant of the evaporator drops by a certain amount in accordance with the temperature of the outside air in the heating cycle of the general heat pump, the refrigerant of the condenser also decreases by that much, so that the blowing temperature of the condenser is difficult to maintain a proper state.

In order to solve the above problems, there have been cases where a separate auxiliary heater is installed in the evaporator or an auxiliary heat exchanger is installed to prevent overcooling of the evaporator.

However, in the conventional case, the use of a separate device such as an auxiliary heater or heat exchanger not only complicates the structure and control system of the device, but also greatly increases the cost of the device. There was a disadvantage in that the management cost increased.

The present invention is to solve all the problems of the conventional heat pump heating cycle, the main purpose is to prevent the freezing, condensation or sexual formation of the evaporator directly due to excessive decrease of the outdoor temperature, and at the same time condensation as a whole It maintains optimal temperature, evaporation temperature and compression efficiency to greatly increase the heating efficiency and durability of the system. For other purposes, it is possible to operate the heating cycle with a simple device without using a separate auxiliary heater or heat source. Significantly reduce manufacturing costs, maintenance and operating costs.

1 is a circuit diagram of a heat pump of the present invention

Figure 2 is a perspective view of the main portion showing a heat exchange device between the refrigerant of the present invention evaporator and the flash gas of the accumulator

Figure 3 is a front view showing the main part showing a heat exchange device between the refrigerant of the present invention evaporator and the flash gas of the accumulator

Figure 4 is a flow chart for the present invention evaporation temperature compensation

<Description of Symbols for Major Parts of Drawings>

10: compressor 20: 4-way valve

30: condenser 40: primary expansion valve

50: accumulator 60: secondary expansion valve

70: evaporator 70a: tube

71: flash line 71a: manifold tube

72: valve

In order to achieve the above object, the present invention connects a flash line via an evaporator between the upper portion of the accumulator and the second stage suction side of the compressor, and the double pipe is adjacent to the evaporator while the path is different from the evaporator. Type manifold tube and connect the manifold tube with the flash line. When the temperature of the main refrigerant flowing through the evaporator tube falls below the set value during the heating of the winter, open the flash line to The heat exchanged between the secondary expansion medium temperature, medium pressure flash refrigerant gas and the secondary expansion low temperature, low pressure main refrigerant gas to prevent functional evaporation and sexual formation of the evaporator, and the main refrigerant after the heat exchange is the first stage of the compressor Connected to the suction side, it is possible to control the superheat degree of the first stage suction side of the compressor, and supply the flash refrigerant gas to the second stage suction side. This is to improve the efficiency of the two-stage compression by increasing the mass and specific volume of the compressed refrigerant.

In particular, by escaping the accumulator's flash refrigerant gas through the flash line, the accumulator's complete phase separation is achieved, and the liquid loss zone at a certain level is ensured, thereby reducing the loss of throttling in the secondary expansion valve. The superheat degree of can be controlled to the optimum state.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.

1 is a configuration circuit diagram of the heating apparatus of the present invention, Figure 2 is an enlarged perspective view of the main part of the evaporator of the present invention, while compressing the refrigerant into a superheated steam of high temperature and high pressure, the compression ratio according to the heating load is easily variable and optimal compression It is connected to the compressor 10 of the multistage centrifugal compression method of two or more stages and the first stage outlet and the second stage outlet of the compressor 10 to open and switch the flow path of the refrigerant to selectively perform cooling / heating operation so as to have efficiency. Is connected to the four-way valve 20 and the outlet side of the four-way valve 20, and heat-exchanges with the superheated refrigerant gas from one or two stages of the compressor 10 to release heating heat and A condenser 30 is provided that begins to liquefy with refrigerant.

The condenser 30 is an indoor unit during heating operation, and its outlet is connected to a primary expansion valve 40 for throttling and reducing the refrigerant to medium temperature and medium pressure, and the primary expansion valve 40 performs phase separation of the refrigerant. An accumulator 50 for temporarily storing a liquid refrigerant is connected, and a secondary expansion valve 60 is connected to the outlet side of the accumulator 50 to throttle and reduce the refrigerant to medium temperature and medium pressure again.

The secondary expansion valve 60 is connected to the evaporator 70, which is an outdoor unit during heating, and the evaporator 70 is connected to the four-way valve 20 again to form a low-temperature, low-pressure liquid phase at the first suction side of the compressor 10. And returning the refrigerant to form one heating cycle.

On the other hand, when the flash line 71 via the evaporator 70 is connected to the upper portion of the accumulator 50 and the second stage suction side of the compressor 10, and the outside air temperature of the evaporator 70 of the heat pump falls below a set value. The flash refrigerant gas of the accumulator 50 is used to prevent freezing due to numbness and erosion of the evaporator 70, and the flash refrigerant gas heat-exchanged with the main refrigerant from the evaporator 70 is the second stage of the compressor 10. The main refrigerant supplied to the suction side and heat-exchanged with the flash refrigerant gas from the evaporator 70 is supplied to the first stage suction side of the compressor 10 so as to increase the compression efficiency with the superheat control of the compressor.

That is, a portion of the evaporator 70 is installed so as to pass through the double-tubular manifold tube 71a, and the inlet / outlet of the manifold tube 71a is connected to the flash line 71, but the manifold tube 71a is provided. ) And the tube 70a of the evaporator 70 are different from each other, and the tube 70a of the evaporator 70 supplies the main refrigerant of low temperature and low pressure to the compressor 10 through the four-way valve 20. Guided to the first stage suction side, the manifold tube 71a of the flash line 71 exchanges flash refrigerant gas of medium temperature and medium pressure from the accumulator 50 through the evaporator 70 and then the second stage suction of the compressor 10. Configured to guide to the side.

Here, the flash line 71 is connected to the valve 72 for controlling the flow rate of the flash refrigerant gas, and the flash line 71 and the manifold tube 71a have a lower temperature than the set value of the evaporator 70. When the outside air temperature of the evaporator 70 falls to a set value (for example, about -5 degrees C or less) in winter, it flows through the low temperature refrigerant | coolant which flows through the tube 70a of the evaporator 70, and the manifold tube 71a. It is configured to exchange heat with flash refrigerant gas of medium temperature and medium pressure.

Therefore, in the heating apparatus using the heat pump of the present invention, as shown in FIGS. 1, 2, and 3, when the compressor 10 is driven, the refrigerant is compressed into superheated steam of high temperature and high pressure in one stage and two stages under isotropy. The compressed refrigerant gas is introduced into the condenser 30 through the four-way valve 20 in a superheated steam state.

Heating is performed while the high temperature refrigerant gas flowing through the condenser 30 and the external air is heated under isothermal isothermal pressure, and the high temperature and high pressure liquid refrigerant that has been heated is irreversibly through the primary expansion valve 40. It is introduced into the accumulator 50 while being throttled and decompressed, and immediately after the gaseous refrigerant (flash refrigerant gas) and the liquid refrigerant are separated from the accumulator 50 and depressurized to medium temperature and medium pressure, the decompressed liquid refrigerant is again secondary. The expansion valve 60 throttles the low-temperature / low-pressure gas / liquid refrigerant.

The low-temperature / low-pressure gas / liquid refrigerant throttled through the secondary expansion valve 60 is evaporated from the evaporator 70 to the low-temperature / low-pressure complete gas phase through the four-way valve 20. It is recovered to the first stage suction side and completes one heating cycle.

During the heating operation, the outside air temperature of the evaporator 70 drops to about −5 ° C., which is a set temperature T, or the temperature T of the main refrigerant flowing through the tube 70a of the evaporator 70 is a flash line 71. When the temperature value t of the flash coolant gas, i.e., becomes smaller than the set value, the pressure at which the coolant gas at the top of the accumulator 50 is formed therein while the valve 72 of the flash line 71 is opened. The vehicle is led to the second stage suction side of the compressor 10 via the flash line 71 and the valve 72 via the manifold tube 71a via the evaporator 70. During this process, the manifold tube 71a The medium-temperature / medium-pressure flash refrigerant gas flowing through the heat exchanger is exchanged with the low-temperature / low-pressure main refrigerant gas flowing through the tube 70a of the evaporator 70 to be connected to the second stage suction side of the compressor 10 from the evaporator 70. The specific volume is significantly reduced by mixing the refrigerant gas discharged from the first stage and the flash refrigerant gas. In addition to the compression efficiency of the second stage, it contributes to the efficiency of the entire compressor and to improve the performance of the heat pump by maintaining the optimum evaporation temperature.

Bypassing some of the refrigerant gas in the accumulator 50 to the compressor 10 through the flash line 71 and the evaporator 70 does not affect the performance of the basic heat pump cycle, it is bypassed at this time The amount of refrigerant gas is irrelevant even if it is interpreted as excess in the heating cycle.

Rather, as the refrigerant gas of the accumulator 50 is avoided through the flash line 71, complete phase separation is formed in the accumulator 50, and a liquid level region of a certain level is ensured, thereby causing loss of throttling in the secondary expansion valve 60. Will be reduced.

In addition, the evaporator 70 absorbs the external heat source only when the refrigerant is evaporated with a gas refrigerant of low temperature and low pressure, whereas the refrigerant of the accumulator 50 maintains a relatively high temperature and high pressure. The degradation of the heating cycle due to passing does not occur at all, but rather, the condensation temperature (condensation refrigerant temperature) of the condenser 30 is lowered as it prevents the subcooling of the winter evaporator 70 (a drop in the outside air suction temperature). In addition, the heating temperature can be maintained by controlling the temperature of the evaporator 70 and the condenser 30 in an optimal state at all times, thereby increasing the heating efficiency according to the operation of the winter heat pump. You will be able to.

Since the main refrigerant heat-exchanged with the flash refrigerant gas from the evaporator 70 is guaranteed a certain degree of superheat, the main refrigerant flows into the first stage suction side of the compressor 10 through the four-way valve 20, and exchanges heat with the main refrigerant from the evaporator 70. Since the flash refrigerant gas is introduced into the second stage suction side of the compressor 10 and mixed with the refrigerant gas discharged in the first stage of the compressor 10, the second stage suction refrigerant temperature of the compressor 10 is relatively decreased and the ratio of the suction refrigerant is reduced. Compression efficiency of the compressor 10 can also be maintained at an optimum state by increasing the mass with decreasing volume, and at the same time, the amount of refrigerant circulation per unit time increases, contributing to an increase in the efficiency of the heating cycle.

As such, the heat pump heating system can be efficiently configured by simply applying a flash line without additionally using a separate auxiliary heater or external heat source, so that the optimum heating cycle can be achieved even when the outside temperature is low so that the system cannot be operated. This heating cycle can be easily applied to low temperature refrigeration cycles or heat pump cycles employing low and medium temperature compression devices.

As described above, the evaporation temperature compensating apparatus and the compensating method of the heat pump of the present invention connect the flash line 71 via the evaporator 70 between the upper portion of the accumulator 50 and the second stage suction side of the compressor 10. However, the manifold tube 71a is connected to the flash line 71 while connecting the valve 72 to the flash line 71 and installing a double-tubular manifold tube 71a to occupy a portion of the evaporator 70. The temperature of the main refrigerant flowing from the accumulator 50 to the evaporator 70 through the secondary chute valve 60 is connected to the flash line 71, the valve 72, the manifold tube and the shell from the accumulator 50. When the set temperature is lower than the temperature of the flash gas passing through the ann tube 71a or when the outdoor temperature of the evaporator 70 is lower than or equal to the set value, the valve 72 of the flash line 71 is opened to maintain the main refrigerant of the evaporator 70. By allowing the flash refrigerant gas in the flash line to exchange heat, By preventing overcooling of the machine, the efficiency of the evaporator and the compressor can be maintained at the optimum state, contributing to the increase of the heating efficiency of the winter heat pump by improving the compression efficiency of the compressor, and eliminating the use of additional auxiliary devices. In addition to simplifying the configuration, it is possible to significantly reduce the cost and operating cost of the device.

Claims (7)

In a heat pump circulating a compressor, a four-way valve, a condenser, an expansion valve, an accumulator, and an evaporator, a flash line through the upper part of the accumulator and the evaporator to bypass the accumulator's flash gas and exchange heat with the refrigerant in the evaporator. And the outlet of the flash line is connected to the suction end of the compressor in order to reduce the specific volume of the compressed refrigerant. The evaporating temperature compensation device of a heat pump according to claim 1, wherein a manifold tube is installed in the evaporator so as to different a path from the refrigerant in the evaporator, and an inlet and an outlet of the manifold tube are connected to the flash line. The apparatus of claim 1 or 2, wherein the flash line is connected to a secondary suction end of the compressor. The apparatus of claim 1, wherein the expansion valve is connected between a condenser, an accumulator, an accumulator, and an evaporator to increase the throttling / decompression efficiency of the heat pump. In the heating cycle of the heat pump in the compression, condensation, expansion, and evaporation step, the flash gas of the accumulator is exchanged with the refrigerant of the evaporator to maintain the refrigerant temperature of the evaporator at a set value, and the heat exchanged flash gas is compressed into a compressor. Evaporating temperature compensation method of the heat pump, characterized in that coupled with the suction refrigerant of the reducing the specific volume of the refrigerant. The method of compensating the evaporation temperature of a heat pump according to claim 5, wherein the refrigerant temperature of the evaporator is heat-exchanged with the flash gas when it is smaller than a set value. The method of claim 5, wherein the flash gas is introduced into the secondary suction end of the compressor.