KR100869082B1 - Dual Refrigerant Refrigeration Equipment by Compulsive Circulation of Secondary Refrigerant - Google Patents

Abstract

The present invention uses the secondary refrigerant R-22 gas as the primary refrigerant R-23 gas so as to maintain the refrigeration temperature at a very low level through heat exchange between two refrigerants circulated along different paths. The present invention relates to a dual refrigerant forced circulation refrigerating device that performs cooling by circulating the R-22 gas after cooling to an extremely low temperature of 103 ° C.

An intercooler 12 which lowers the pressure of the primary refrigerant from the low pressure compressor 11a; A high pressure compressor (11b) for compressing the primary refrigerant from the intercooler (12) again and supplying it to the condenser (13); A first heat exchanger (30) for completely liquefying the primary refrigerant and raising the temperature of the secondary refrigerant through heat exchange between the primary refrigerant and the secondary refrigerant from the condenser (13); A high pressure receiver 14 for temporarily storing the primary refrigerant from the first heat exchange unit 30 and circulating only the primary refrigerant in the liquid phase; A second heat exchange part 35 for cooling the secondary refrigerant to cryogenic temperature by using latent heat of evaporation due to vaporization of the primary refrigerant; A gas injector 15 provided at an inlet end of the second heat exchanger 35 to inject a liquid primary refrigerant from the high pressure receiver 14 into the second heat exchanger; A low pressure receiver 20 in which a low temperature secondary refrigerant from the second heat exchange part 35 is stored; A first liquid pump (21) for supplying a liquid secondary coolant to the first heat exchange part (30) from a lower end of the low pressure receiver (20); An evaporator coil 25 for performing a freezing operation using latent heat of evaporation according to vaporization of the secondary refrigerant of the low pressure receiver 20; And a second liquid pump 23 for supplying a liquid secondary coolant to the evaporator coil 25 from a lower end of the low pressure receiver 20.

Therefore, by improving the pressure of the refrigerant supplied to the condenser, the cooling temperature is drastically lowered, and the secondary refrigerant can be cooled to cryogenic temperature simply by circulating the secondary refrigerant using a liquid pump without using a separate compressor. Can be.

Refrigerating unit, refrigerant, forced circulation, compressor, liquid pump, R-22, R-23, cryogenic

Description

Dual Refrigerant Refrigeration Equipment by Compulsive Circulation of Secondary Refrigerant

1 is a block diagram schematically showing a refrigeration cycle of a typical refrigeration apparatus.

2 is a configuration diagram showing a dual refrigerant forced circulation refrigeration apparatus according to the present invention.

<Description of the symbols for the main parts of the drawings>

11a: low pressure compressor 11b: high pressure compressor

12: intercooler 13: condenser

14: high pressure receiver 15: gas injector

16: gas filter 17: intercooler gas jet

20: low pressure receiver 21: first liquid pump

23: second liquid pump 25: evaporator coil

27: third liquid pump 29: cooler unit

30: first heat exchanger 35: second heat exchanger

The present invention relates to a refrigerating device, and more particularly to a dual refrigerant forced circulation refrigerating device to maintain a very low level of the freezing temperature through heat exchange between two refrigerants circulated along different paths.

In general, freezing means to artificially take away the heat of an object or space so that the temperature is lower than the surrounding temperature and maintain the low temperature. However, cooling down the object of a temperature higher than room temperature, such as cooling a hot coffee or cooling a car radiator, is called cooling rather than freezing. Therefore, in the case of refrigeration, it means to make an object of room temperature or a temperature lower than room temperature to the lower temperature below minus when it is rigorously determined. The object of such freezing includes agricultural products, water, livestock products, as well as industrial products, and even natural products and fluids are subject to freezing.

 This refrigeration is carried out using the latent heat of evaporation of the refrigerant. Usually, when you hit the wind after sweating, you feel cool because the sweat evaporates and takes heat away from the body. That is, in the process of the liquid sweat evaporating to a gas, the heat required for the phase change from the liquid state to the gaseous state is taken from the liquid that has not yet evaporated, and the liquid is compensated for by the skin.

As such, the heat required for the phase change when changing from the liquid state to the gas state is called heat of evaporation or latent heat of evaporation. A mechanical device using such latent heat of evaporation is a refrigerating device, and a refrigerant having a large latent heat of evaporation is selected for use in the freezing device. Ammonia, CFC, HFC and HCFC liquid refrigerants used in most refrigerating apparatuses are gas at room temperature and evaporate at a temperature below -30 ° C.

The basic principle of refrigeration, which cools down as the temperature drops rapidly while the liquid absorbs heat as gas evaporates, has been known for a long time. In the early refrigerators, sulfur dioxide, ammonia and methyl chloride were used as refrigerants. This high level caused a great risk with a slight leak. Therefore, the development of a stable and non-toxic refrigerant has been required.

As a result, a boiling point has to be in the range of -40 ~ 0 ℃, a stable, non-toxic, non-flammable and corrosion-resistant chemicals have been developed as a refrigerant. The new refrigerant is a CFC compound called dichlorodifluoromethane (CCl ₂ F ₂ ), designated R (Refrigerant) -12, which is a trade name of DuPont, a Freon gas we know and a GM partner. Freon gas has been used as a refrigerant for refrigerators, air conditioners, etc. because of its chemically stable properties, and is also used as a solvent, a foaming agent, a spray for a spray or a fire extinguisher.

As shown in FIG. 1, the refrigerating device using the refrigerant includes a compressor 51 for compressing the refrigerant at high temperature and high pressure, and a condenser 52 for condensing the refrigerant compressed by the compressor 51 to the liquid phase by heat radiation. And, an expansion valve 54 for expanding the liquid refrigerant condensed in the condenser 52 to a low pressure state by the throttling action, and a space for freezing using the latent heat of evaporation while evaporating the refrigerant expanded in the expansion valve 54. Or an evaporator 55 which takes heat away from the article, a receiver 53 installed at the inlet end of the expansion valve 54 to supply only liquid refrigerant to the expansion valve 54, the evaporator 55 and the compressor. It is provided between the 51 and the liquid separator 56 to separate the liquid refrigerant and to supply only the refrigerant gas to the compressor (51).

Conventional refrigeration apparatus configured as described above is to be made the freezing operation in the evaporator unit.

The refrigerant compressed by the compressor (51) is condensed in the condenser (52), and then passes through the receiver (53). Only the liquid refrigerant is supplied to the expansion valve (54). The refrigerant in a state enters the evaporator 55. The evaporator 55 absorbs the latent heat of evaporation from the surroundings while the refrigerant is evaporated, so the temperature of the space or the object in which the evaporator 55 is installed is lowered to perform the freezing operation. The refrigerant evaporated in the evaporator 55 is returned to the compressor 51 and compressed.

On the other hand, the receiver 53 is installed at the inlet end of the expansion valve 54 serves to store the refrigerant in the liquid state from the condenser 52. That is, while temporarily storing the liquid refrigerant condensed in the condenser 52, only the refrigerant required by the evaporator 55 is sent to the expansion valve 54. Therefore, because it serves as a kind of safety device, the use of the receiver 53 reduces the risk of the refrigeration cycle.

In addition, the liquid separator 56 located between the evaporator 55 and the compressor 51 separates the refrigerant in the liquid state that is not completely vaporized from the refrigerant discharged from the evaporator 55 so that only the refrigerant in the gas state is used in the compressor. Will be sent to (51). If the refrigerant from the evaporator 55 is not completely vaporized, the liquid refrigerant is contained in the refrigerant gas, and when the operation of the refrigeration unit is suspended, the liquid remaining in the pipeline between the evaporator 55 and the compressor 51 remains. The refrigerant gas is changed into a liquid phase. Therefore, a liquid refrigerant, which is an incompressible fluid, may be introduced into the compressor 51, and thus, a liquid compression phenomenon may occur, causing hammering noise, so-called hammering noise, and of course, the liquid refrigerant is compressed. If not, burnout of the compressor 51 may occur. Therefore, the necessity of fundamentally blocking the introduction of the liquid refrigerant into the compressor 51 is required, and for this purpose, a liquid separator 56 is installed.

However, the above-mentioned conventional refrigeration apparatus has a limitation in improving the refrigeration performance of the second heat exchanger unless the capacity of the compressor is increased because the refrigeration cycle is configured using one refrigerant.

Therefore, when freezing agricultural products such as the freezing temperature is low, it takes a long time, when using a high capacity compressor to lower the freezing temperature, the use efficiency of energy is lowered.

The present invention has been made in order to solve the above-described problems, and while circulating the two different refrigerants through different paths, heat exchange is performed between the two refrigerants, and at the same time, the pressure of the primary refrigerant that exchanges heat with the secondary refrigerant is It is an object of the present invention to provide a dual refrigerant forced circulation refrigerating device that can be improved to lower the secondary refrigerant to cryogenic temperatures.

In addition, in the present invention, in lowering the temperature of the secondary refrigerant, a dual refrigerant forced circulation type that allows the temperature of the secondary refrigerant to be lowered to the desired cryogenic temperature only by forcibly circulating the secondary refrigerant without using a compressor. It is an object to provide a refrigerating device.

According to the dual refrigerant forced circulation refrigeration apparatus of the present invention for achieving the above object, an intercooler for reducing the pressure of the primary refrigerant from the low pressure compressor; A high pressure compressor for compressing the primary refrigerant from the intercooler again and supplying it to the condenser; A first heat exchanger configured to completely liquefy the primary refrigerant and to raise the temperature of the secondary refrigerant through heat exchange between the primary refrigerant and the secondary refrigerant from the condenser; A high pressure receiver for temporarily storing the primary refrigerant from the first heat exchange unit and allowing only the liquid primary refrigerant to be circulated; A second heat exchange unit cooling the secondary refrigerant to cryogenic temperature by using latent heat of evaporation due to vaporization of the primary refrigerant; A gas injector provided at an inlet end of the second heat exchanger to inject a liquid primary refrigerant from the high pressure receiver into the second heat exchanger; A low pressure receiver for storing a low temperature secondary refrigerant from the second heat exchange unit; A first liquid pump for supplying a liquid secondary coolant to the first heat exchange part from a lower end of the low pressure receiver; An evaporator coil configured to perform a freezing operation using latent heat of evaporation according to vaporization of the secondary refrigerant of the low pressure receiver; And a second liquid pump for supplying a liquid secondary coolant to the evaporator coil from a lower end of the low pressure receiver.

According to the dual refrigerant forced circulation refrigeration apparatus of the present invention, a gas filter for vaporizing a part of the primary liquid refrigerant from the high pressure receiver and a primary refrigerant vaporized by the gas filter are directly injected into the intercooler. It characterized in that it further comprises an intercooler gas injector.

Further, according to the dual refrigerant forced circulation refrigerating device of the present invention, the first heat exchange unit may be configured in multiple stages, characterized in that the oil heater for heating the oil contained in the primary refrigerant on one side of the compressor do.

In addition, according to the dual refrigerant forced circulation type refrigeration apparatus of the present invention, a unit cooler for cooling by using a cryogenic secondary refrigerant from the low pressure receiver and a third liquid pump for feeding the secondary refrigerant to the unit cooler It characterized in that it further comprises.

According to the dual refrigerant forced circulation refrigeration apparatus of the present invention, the flow path of the secondary refrigerant in the first heat exchange unit and the second heat exchange unit is longer than the flow path of the primary refrigerant. do.

Hereinafter, a dual refrigerant forced circulation refrigeration apparatus of the present invention with reference to the accompanying drawings.

Figure 2 is a block diagram showing a dual refrigerant forced circulation refrigeration apparatus according to the present invention.

The dual refrigerant forced circulation refrigerating device according to the present invention includes a low pressure compressor (11a) for compressing the primary refrigerant; An intercooler (12) for lowering the pressure of the primary refrigerant from the low pressure compressor (11a); A high pressure compressor (11b) for compressing the primary refrigerant from the intercooler (12) again and supplying it to the condenser (13); A first heat exchanger (30) for completely liquefying the primary refrigerant and raising the temperature of the secondary refrigerant through heat exchange between the primary refrigerant and the secondary refrigerant from the condenser (13); A high pressure receiver 14 for temporarily storing the primary refrigerant from the first heat exchange unit 30 and circulating only the primary refrigerant in the liquid phase; A second heat exchange part 35 for cooling the secondary refrigerant to cryogenic temperature by using latent heat of evaporation due to vaporization of the primary refrigerant; A gas injector 15 provided at an inlet end of the second heat exchanger 35 to inject a liquid primary refrigerant from the high pressure receiver 14 into the second heat exchanger; A low pressure receiver 20 in which a low temperature secondary refrigerant from the second heat exchange part 35 is stored; A first liquid pump (21) for supplying a liquid secondary coolant to the first heat exchange part (30) from a lower end of the low pressure receiver (20); An evaporator coil 25 for performing a freezing operation using latent heat of evaporation according to vaporization of the secondary refrigerant of the low pressure receiver 20; A second liquid pump 23 for supplying a liquid secondary coolant to the evaporator coil 25 from a lower end of the low pressure receiver 20; An intercooler gas for directly injecting a part of the liquid primary refrigerant from the high pressure receiver 14 and the primary refrigerant vaporized by the gas filter 16 to the intercooler 12. An injector 17; Including a unit cooler 29 for cooling by using the cryogenic secondary refrigerant from the low-pressure receiver 20 and a third liquid pump 27 for pumping the secondary refrigerant to the unit cooler 29 It is composed.

Here, the first heat exchange unit 30 is preferably composed of a plurality of stages, in the present embodiment is composed of a first heat exchanger 31 and a second heat exchanger (32). In addition, R-23 (trifluoromethane; HCF ₃ ) is used as the primary refrigerant, and R-22 (hydrochlorofluoromethane; CHClF ₂ ) is used as the secondary refrigerant. Of course, ammonia (NH ₃ ) may be used instead of R-22 as the secondary refrigerant. In addition, the flow path of the secondary refrigerant in the first heat exchange unit 30 and the second heat exchange unit 35 may be longer than that of the primary refrigerant.

Reference numeral 22 is a pressure gauge of the low pressure receiver 20, 24 is a safety valve of the low pressure receiver 20.

The dual refrigerant forced circulation refrigerating device of the present invention configured as described above is configured to reduce the temperature of the secondary refrigerant through a heat exchange between the primary refrigerant and the secondary refrigerant of high pressure without compressing the secondary refrigerant that actually performs the freezing operation. It is lowered to the cryogenic temperature of ~ -103 ℃ so that the rapid freezing operation is performed in the cryogenic state.

The pressure of the primary refrigerant compressed by the low pressure compressor 11a is lowered while passing through the intercooler 12, and the primary refrigerant in the gas state is compressed to a higher pressure in the high pressure compressor 11b and then supplied to the condenser 13. Condensation. The primary refrigerant condensed in the condenser 13 is cooled through heat exchange with the secondary refrigerant while passing through the first heat exchange unit 30 consisting of two heat exchangers 31 and 32, and then the high pressure receiver 14. Is temporarily saved. The primary refrigerant in the liquid state from the high pressure receiver 14 is injected into the second heat exchange part 35 by the gas injector 15, and exchanges heat with the secondary refrigerant in the second heat exchange part 35. Will be That is, as the primary refrigerant, e.g., R-23, whose evaporation temperature is -80 ° C, evaporates, it absorbs latent heat of evaporation from the secondary refrigerant, such as R-22, whose evaporation temperature is -40 ° C. Will descend.

In this case, since the flow path of the secondary refrigerant in the first heat exchange unit 30 and the second heat exchange unit 35 is longer than the flow path of the primary refrigerant, the first heat exchange unit 30 In the primary refrigerant is sufficiently cooled, the second heat exchange unit 35 is the secondary refrigerant is sufficiently cooled to cryogenic temperatures of -98 ℃ ~ 103 ℃.

The secondary refrigerant in the liquid state stored in the low pressure receiver 20 is pumped by the first liquid pump 21 and supplied to the first heat exchange unit 30, and the primary refrigerant in the first heat exchange unit 30. Through the heat exchange with the temperature rises to some extent and at the same time to decrease the temperature and pressure of the primary refrigerant to increase the condensation efficiency. The secondary refrigerant from the first heat exchange unit 30 is supplied to the second heat exchange unit 35, and is changed to a cryogenic state through heat exchange with the primary refrigerant in the second heat exchange unit 35. That is, since the primary refrigerant is evaporated in the second heat exchanger 35, the latent heat of evaporation necessary for evaporation is deprived of the primary refrigerant, and is changed to a cryogenic state of -98 ° C to -103 ° C, and then returned to the low pressure receiver 20 do.

In addition, the secondary refrigerant in the cryogenic state stored in the low pressure receiver 20 is supplied to the evaporator coil 25 by the second liquid pump 23, and performs a freezing operation while being evaporated in the evaporator coil 25. Done. The secondary refrigerant in the gaseous state evaporated from the evaporator coil 25 is liquefied by the secondary refrigerant in the cryogenic state returned to the low pressure receiver 20 and returned from the second heat exchanger 35 and the low pressure receiver 20 is stored.

In addition, since a part of the cryogenic secondary refrigerant from the low pressure receiver 20 is supplied to the unit cooler 29 by the third liquid pump 27, refrigeration and cooling using the unit cooler 29 are possible. Done. A portion of the primary refrigerant from the high pressure receiver 14 is vaporized while passing through the gas filter 16, and the vaporized primary refrigerant is injected into the intercooler 12 by the intercooler gas injector 17. The refrigerant pressure in the intercooler 12 is lowered.

Therefore, the temperature of the secondary refrigerant is merely desired by forcibly circulating the secondary refrigerant using the liquid pump 21 without providing a separate compressor for compressing the secondary refrigerant that performs the freezing operation. Can be lowered to the level. In addition, since the primary refrigerant from the condenser 13 undergoes heat exchange with the secondary refrigerant during the circulation of the primary refrigerant before passing through the gas injector 15, the temperature and pressure of the primary refrigerant are lowered to reduce the pressure of the low pressure compressor ( It is possible to prevent the pressure of the primary refrigerant returned to 11a) from rising to high pressure. Since only the refrigerant in the gaseous state is first supplied from the low pressure compressor 11a and supplied to the intercooler 12, the gaseous refrigerant is supplied to the high pressure compressor 11b, compressed to high pressure, and then supplied to the condenser 12. The pressure of the condensed refrigerant condensed in the condenser 12 also increases, but since sufficient heat exchange is performed between the primary refrigerant and the secondary refrigerant in the first heat exchange unit 30, the pressure of the refrigerant passing through the first heat exchange unit 30. This will not rise excessively.

Although the preferred embodiments of the present invention have been described above, the scope of the present invention is not limited to such specific embodiments, and those of ordinary skill in the art are appropriately within the scope described in the claims of the present invention. Changes will be possible.

As described above, according to the dual refrigerant forced circulation refrigerating device of the present invention, the heat exchange is performed between two kinds of refrigerants having different evaporation temperatures, and the pressure of the refrigerant supplied to the condenser is improved, thereby dramatically increasing the freezing temperature. It is possible to cool the secondary refrigerant to cryogenic temperature by simply circulating the secondary refrigerant by using a liquid pump without using a separate compressor.

In addition, according to the dual refrigerant forced circulation type refrigeration apparatus of the present invention, as the secondary refrigerant is cooled to cryogenic temperature, there is another effect that the freezing performance is improved to shorten the time required for freezing agricultural and marine products.

Claims (6)

An intercooler 12 which lowers the pressure of the primary refrigerant from the low pressure compressor 11a; A high pressure compressor (11b) for compressing the primary refrigerant from the intercooler (12) again and supplying it to the condenser (13); A first heat exchanger (30) for completely liquefying the primary refrigerant and raising the temperature of the secondary refrigerant through heat exchange between the primary refrigerant and the secondary refrigerant from the condenser (13); A high pressure receiver 14 for temporarily storing the primary refrigerant from the first heat exchange unit 30 and circulating only the primary refrigerant in the liquid phase; A second heat exchange part 35 for cooling the secondary refrigerant to cryogenic temperature by using latent heat of evaporation due to vaporization of the primary refrigerant; A gas injector 15 provided at an inlet end of the second heat exchanger 35 to inject a liquid primary refrigerant from the high pressure receiver 14 into the second heat exchanger; A low pressure receiver 20 in which a low temperature secondary refrigerant from the second heat exchange part 35 is stored; A first liquid pump (21) for supplying a liquid secondary coolant to the first heat exchange part (30) from a lower end of the low pressure receiver (20); An evaporator coil 25 for performing a freezing operation using latent heat of evaporation according to vaporization of the secondary refrigerant of the low pressure receiver 20; And a second liquid pump (23) for supplying a liquid secondary coolant to the evaporator coil (25) from a lower end of the low pressure receiver (20). The method of claim 1, An intercooler gas for directly injecting a part of the liquid primary refrigerant from the high pressure receiver 14 and the primary refrigerant vaporized by the gas filter 16 to the intercooler 12. Dual refrigerant forced circulation refrigeration apparatus further comprises an injector (17). The method of claim 1, The first heat exchange unit 30 is a dual refrigerant forced circulation refrigeration apparatus, characterized in that consisting of multiple stages. The method of claim 1, It further comprises a unit cooler 29 for cooling by using the cryogenic secondary refrigerant from the low pressure receiver 20 and a third liquid pump 27 for feeding the secondary refrigerant to the unit cooler 29 Dual refrigerant forced circulation refrigeration apparatus characterized in that. The method of claim 1, The dual refrigerant forced circulation refrigerating device, characterized in that the flow path of the secondary refrigerant in the first heat exchange unit 30 and the second heat exchange unit (35) is formed longer than the flow path of the primary refrigerant. The method according to any one of claims 1 to 5, And the primary refrigerant is R-23, and the secondary refrigerant is R-22.

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