WO2017123042A1 - Deep freezer - Google Patents

Abstract

An embodiment of the present invention relates to a deep freezer. A deep freezer according to an embodiment of the present invention comprises a plurality of heat exchangers installed to an inlet pipe and performing a heat exchange of a mixed refrigerant suctioned into a compressor. The mixed refrigerant comprises: a high temperature refrigerant which is one selected from among butane (N-butane), 1-butene, and isobutane; and a low temperature refrigerant consisting of ethylene.

Description

Deep freezer

Embodiments of the present invention relate to a deep freezer.

A deep freezer is understood as a device that drives a refrigeration cycle to form a storage compartment in a cryogenic environment of -60 ° C to -80 ° C or less.

In order to implement the refrigeration cycle, a low boiling point refrigerant may be used. However, in the case of using the refrigerant having a low boiling point alone, the discharge pressure of the compressor is increased, thereby reducing the reliability of the compressor.

Therefore, two or more mixed refrigerants having different boiling points may be used in the refrigerating cycle for implementing the temperature. In the mixed refrigerant, a mixed refrigerant that does not change temperature in a quasi-equilibrium state when liquefaction or vaporization occurs between a liquid phase and a gas under a predetermined pressure, that is, an azeortropic refrigerant mixture and a temperature in which the temperature is changed during the liquefaction or vaporization process Non-azeortropic refrigerant mixtures are included.

The azeotropic mixed refrigerant exists only in a specific component ratio and exhibits thermodynamic properties such as pure substances. On the other hand, the azeotropic mixed refrigerant may vary in evaporation pressure or temperature depending on its composition.

On the other hand, the azeotropic mixed refrigerant has a disadvantage in that it is difficult to implement a deep temperature (extreme cryogenic), it may be preferable to use the azeotropic mixed refrigerant in order to implement a deep temperature.

However, even when the non-azeotropic mixed refrigerant is used, the discharge pressure or the condensation pressure of the compressor is relatively high. Therefore, it is necessary to select a compressor that fits the discharge pressure range. In general, a compressor used in a deep freezer may use a commercial compressor having a large operating pressure range, that is, a high discharge pressure value.

However, the commercial compressor has a problem in that the operation noise for the deep freezer is lowered due to the large operation noise.

On the other hand, the information of the prior literature related to the deep freezer is as follows.

1.Registration No. (Registration Date): US 7,299,653B2 (November 27, 2007)

2. Name of invention: Refrigerator system using non-azeotropic refrigerant, and non-azeotropic refrigerant for very low temperature used for the system.

According to the prior document as described above, it is possible to implement a deep temperature environment using two or more mixed refrigerants, but the mixing ratio is not optimized, there was a problem that it is difficult to meet both the core temperature implementation and the proper discharge pressure of the compressor.

In detail, when the ratio of the refrigerant having a high boiling point is high, it is not easy to implement the temperature, and when the ratio of the refrigerant having the low boiling point is high, the discharge pressure of the compressor is increased, thereby causing a problem in reliability of the compressor.

On the other hand, the refrigerating cycle disclosed in the prior document, the refrigerant discharged from the compressor is condensed in the condenser to perform heat exchange with the evaporative refrigerant, it is configured to implement the temperature by the heat exchange. However, there is a problem in that the dryness of the refrigerant is increased in the process of expanding in the expansion device after the heat exchange, thereby reducing the ratio of the liquid refrigerant in the refrigerant flowing into the evaporator, thereby decreasing the cooling power.

Embodiments of the present invention have been proposed to solve the above problems, and an object thereof is to provide a deep freezer that can implement a desired cryogenic environment.

In addition, an embodiment of the present invention is to provide a deep freezer that can lower the condensation pressure of the refrigeration cycle.

In addition, an embodiment of the present invention is to provide a deep freezer that can reduce the noise generated in the compressor to increase the reliability of the compressor.

The deep-temperature freezer according to the embodiment of the present invention, the deep-temperature freezer according to the embodiment of the present invention includes a plurality of heat exchangers installed in the suction pipe and performing heat exchange of the mixed refrigerant sucked into the compressor.

The heat exchanger includes a first heat exchanger, the first heat exchanger, the first heat exchanger for guiding the flow of the mixed refrigerant sucked into the compressor; And a condensation heat exchanger configured to perform heat exchange with the first suction heat exchanger and to guide the flow of the condensation pipe.

The length of the first suction heat exchange or the condensation heat exchange unit is characterized in that formed in the range of 3.5 ~ 5m.

The pipe diameter of the condensation heat exchange part is larger than the pipe diameter of the expansion device.

The pipe diameter of the condensation heat exchange part is formed within the range of 3.5 to 4.5 times the pipe diameter of the expansion device.

The heat exchanger includes a second heat exchanger, and the second heat exchanger includes: a second suction heat exchanger provided at one side of the first suction heat exchanger to guide the flow of the mixed refrigerant sucked into the compressor; And the expansion device performing heat exchange with the second suction heat exchange unit.

The first suction heat exchange unit and the condensation pipe, or the second suction heat exchange unit and the expansion device are in contact with each other to perform heat exchange.

The first suction heat exchange unit and the condensation pipe, or the second suction heat exchange unit, and the expansion device may be coupled by soldering.

A heat exchanger connection pipe disposed between the first and second heat exchangers to prevent heat exchange between the expansion device and the condensation heat exchange unit, wherein the first heat exchange unit and the second heat exchange unit are installed in the heat exchanger. Characterized in that spaced apart from each other by a connection pipe.

The first heat exchanger is installed at the outlet side of the second heat exchanger based on the flow direction of the refrigerant flowing through the suction pipe.

The second heat exchanger is installed at the outlet side of the first heat exchanger based on the flow direction of the refrigerant flowing through the condensation pipe.

The evaporator includes a first evaporator and a second evaporator connected in series with each other, and the second evaporator is installed at an outlet side of the first evaporator.

The evaporator includes a first evaporator and a second evaporator connected in parallel with each other, and the expansion device includes a first expansion device installed at an inlet side of the first evaporator and an inlet side of the second evaporator. 2 expansion devices are included.

The first and second expansion devices and the suction pipe are coupled to each other to exchange heat.

The evaporator, the first evaporator is installed on the outlet side of the expansion device; A second evaporator connected in series with the outlet side of the first evaporator; And a third evaporator connected in series to the outlet side of the second evaporator.

Two independent refrigeration cycles are driven, each independent refrigeration cycle comprising the compressor, condenser, expansion device, evaporator and a plurality of heat exchangers.

A deep freezer according to an embodiment of the present invention includes a compressor for compressing a mixed refrigerant, and the mixed refrigerant includes any one of butane (N-Butane), 1-butene (1-Butene), and isobutane (Isobutane). The low temperature refrigerant composed of the selected high temperature refrigerant and ethylene (Ethylene) is included.

The mixed refrigerant includes butane (N-Butane) and ethylene (Ethylene).

The butane (N-Butane) is determined in the range of 80% to 85% by weight, and the ethylene is determined in the range of 15% to 20% by weight.

The compressor is operated in a set pressure range, and the set pressure range includes a range in which the maximum discharge pressure of the compressor is 25 bar or less.

The set pressure range includes a range in which the minimum suction pressure of the compressor is 1 bar or more.

The compressor is operated within a set temperature range, and the set temperature range includes a range in which the maximum discharge temperature of the compressor is 120 ° C. or less.

The deep freezer includes a storage compartment having a temperature value of -60 ° C or lower.

The compressor includes a domestic compressor operated under pressure conditions of at least 1 bar of the minimum suction pressure and of 25 bar or less of the maximum discharge pressure.

A condensation pipe extending from the outlet side of the condenser to the expansion device to guide the flow of the adsorption refrigerant; A suction pipe extending from the outlet side of the evaporator to the compressor to guide suction of the mixed refrigerant into the compressor; And a plurality of heat exchangers installed in the suction pipe and performing heat exchange of the mixed refrigerant sucked into the compressor.

According to an embodiment of the present invention, the refrigerant condensed in the condenser passes through a plurality of heat exchangers before entering the evaporator, thereby lowering the condensation pressure of the refrigeration cycle and preventing rise in dryness when the condensed refrigerant passes through the expansion device. The effect is that it can.

In detail, since the plurality of heat exchangers include a first heat exchanger for performing heat exchange between the refrigerant passing through the condenser and the suction refrigerant sucked into the compressor, the condensation pressure of the refrigeration cycle is increased during the heat exchange process in the first heat exchanger. Can be lowered. As a result, there is an advantage that it is possible to use a household compressor having a low discharge pressure and low noise, which is used in a general refrigerator.

In addition, the temperature of the suction refrigerant is increased to prevent the introduction of the liquid refrigerant into the compressor, thereby improving the operating reliability of the compressor.

The plurality of heat exchangers may include a second heat exchanger that performs heat exchange between the refrigerant passing through the expansion device after being heat exchanged in the first heat exchanger and the suction refrigerant sucked into the compressor, and thus the refrigerant may be removed from the expansion device. It is possible to prevent the increase of dryness in the process of decompression.

As a result, the ratio of the liquid refrigerant in the refrigerant flowing into the evaporator has an advantage that the heat of evaporation, that is, the cooling power can be improved.

In addition, since the diameter of the condensation heat exchanger constituting the first heat exchanger is larger than the diameter of the expansion device constituting the second heat exchanger, condensation may be easily performed while the refrigerant passes through the first heat exchanger. The effect is that the condensation temperature and condensation pressure can be lowered.

In addition, since the length of the first heat exchanger is proposed as an optimum range, heat exchange can be performed, and thus, the refrigerant cycle characteristics can satisfy the operating conditions of the domestic compressor and improve the operation reliability of the compressor.

In addition, the first heat exchanger may be configured by a combination of a condensation pipe and a suction pipe, and the second heat exchanger may be configured by a combination of a capillary tube and a suction pipe, thereby improving heat exchange efficiency.

In addition, since the condensation refrigerant passing through the condenser may be introduced into the second heat exchanger after being heat exchanged in the first heat exchanger, the condensation pressure may be lowered first and dryness may be prevented in the expansion process.

In addition, since the weight ratio of the azeotropic mixed refrigerant can be optimally proposed, it is possible to implement a desired cryogenic environment and to satisfy an appropriate discharge pressure of the domestic compressor.

1 is a view showing a refrigeration cycle provided in a deep freezer according to a first embodiment of the present invention.

2 is a view showing the configuration of the first and second heat exchangers according to the first embodiment of the present invention.

FIG. 3 is a P-h diagram for a deep freezer according to a first embodiment of the present invention. FIG.

4 is an experimental graph showing an optimum range of the length of the first heat exchanger according to the first embodiment of the present invention.

5 is an experimental graph showing a plurality of result values that vary depending on the amount of refrigerant of the azeotropic mixed refrigerant according to the first embodiment of the present invention.

6 is a view showing a refrigeration cycle provided in the freezer temperature according to the second embodiment of the present invention.

7 is a view showing a refrigeration cycle provided in the freezer temperature according to the third embodiment of the present invention.

8 is a view showing a refrigerating cycle provided in a deep-temperature freezer according to a fourth embodiment of the present invention.

9 is a view showing a refrigeration cycle provided in a deep-temperature freezer according to a fifth embodiment of the present invention.

Hereinafter, with reference to the drawings will be described a specific embodiment of the present invention. However, the spirit of the present invention is not limited to the embodiments presented, and those skilled in the art who understand the spirit of the present invention can easily suggest other embodiments within the scope of the same idea.

1 is a view showing a refrigerating cycle provided in a deep-temperature freezer according to a first embodiment of the present invention, Figure 2 is a view showing the configuration of the first and second heat exchangers according to the first embodiment of the present invention, 3 is a pH diagram for the temperature freezer according to the first embodiment of the present invention, Figure 4 is an experimental graph showing the optimum range of the length of the first heat exchanger according to the first embodiment of the present invention, Figure 5 Is an experimental graph showing a number of result values that vary depending on the amount of refrigerant in the azeotropic mixed refrigerant according to the first embodiment of the present invention.

Referring to FIG. 1, in the deep freezer 10 according to the first embodiment of the present invention, a refrigeration cycle in which compression, condensation, expansion, and evaporation of a refrigerant are repeated may be operated. A compressor 110 capable of compressing the refrigerant is included. The compressor 110 may include a household compressor used in a general household refrigerator.

In one example, the temperature or pressure operating range of the compressor 110 is as follows. The compressor 110 may be configured such that the maximum discharge pressure is 25 bar or less, the maximum discharge temperature is 120 ° C. or less, and the minimum suction pressure is 1 bar or less. Household compressor 110 having such a temperature or pressure range has the advantage that the operation noise is generated very little.

The refrigerant sucked into the compressor 110 includes a mixed refrigerant. The mixed refrigerant includes a first refrigerant having a first boiling point and a second refrigerant having a second boiling point lower than the first boiling point. The first refrigerant may be referred to as a "high temperature refrigerant", and the second refrigerant may be referred to as a "low temperature refrigerant".

As the refrigerant includes the mixed refrigerant, an evaporation temperature, i.e., a cryogenic temperature, required in the deep freezer may be realized, and the pressure of the refrigerant discharged from the compressor 110 may be formed within a predetermined range.

In detail, the core temperature may be realized by the characteristics of the low temperature refrigerant. However, since the low temperature refrigerant has a relatively high discharge pressure when compressed in the compressor 110, the low temperature refrigerant may adversely affect the reliability of the compressor, particularly the domestic compressor 110 applied to the present embodiment. Therefore, in order to lower the discharge pressure, a high temperature refrigerant having a relatively low discharge pressure may be mixed.

However, simply mixing the low temperature refrigerant and the high temperature refrigerant may cause a problem that the discharge pressure of the mixed refrigerant is higher than the operating pressure of the domestic compressor 110 used in the present embodiment.

In order to solve this problem, it is possible to use a commercial compressor having a large operating pressure range, but in this case, the reliability of the deep-temperature freezer may be degraded due to very high operating noise. Therefore, the present embodiment proposes a ratio of the mixed refrigerant, that is, an appropriate ratio of the high temperature coolant and the low temperature coolant, which may correspond to the operating pressure or the operating temperature range of the domestic compressor 110.

In general, isopentane, 1,2-butadiene, butane (N-Butane), 1-butene or 1-butene isobutane is included in the high temperature refrigerant. May be included. Physical properties of the high temperature refrigerant are shown in Table 1 below.

High Temperature Refrigerant	Evaporation temperature (1bar), ℃	Evaporation temperature (20bar), ℃
ISOPENTANE	27.5	154.7
1,2-BUTADIENE	10.3	124.8
N-BUTANE	-0.9	114.5
1-BUTENE	-6.6	105.8
ISOBUTANE	-12	100.7

Based on the pressure of 1 bar, in the case of the isopentane and 1,2-butadiene, the evaporation temperature tends to be somewhat high. Accordingly, when the isopentane and 1,2-butadiene are used as the high temperature refrigerant according to the present embodiment, even when mixed with the low temperature refrigerant, it is difficult to realize a deep temperature. This happens.

On the other hand, based on 1 bar, in the case of butane (N-Butane), 1-butene (1-Butene) and isobutane (Isobutane), the evaporation temperature has a value of 0 ℃ or less. Therefore, any one of butane (N-Butane), 1-butene (1-Butene) and isobutane (Isobutane) can be used as a refrigerant for high temperature according to the present embodiment in a broad sense.

However, in the case of the 1-butene and isobutane, the evaporation temperature is slightly lower, and when mixed with the low temperature refrigerant, a deep temperature may be realized, but the discharge pressure of the compressor may be somewhat higher. Problems may arise. Therefore, preferably, as the high temperature refrigerant according to the present embodiment, butane (N-Butane) having an evaporation temperature close to 0 ° C based on 1 bar is used.

Meanwhile, the low temperature refrigerant may include ethane or ethylene. Physical properties of the low temperature refrigerant are shown in Table 2 below.

Low Temperature Refrigerant	Evaporation temperature (1bar), ℃	Evaporation temperature (20bar), ℃
ETHANE	-88.8	-182.8
ETHYLENE	-104	-169.15

Based on the pressure 1bar, in the case of the ethane (Ethane), the evaporation temperature tends to be somewhat high. Therefore, when using the ethane (Ethane) as the low-temperature refrigerant according to this embodiment, there is a problem that the implementation of the deep temperature is limited.

On the other hand, on the basis of the pressure 1bar, in the case of ethylene (Ethylene), the evaporation temperature has a value of -100 ℃ or less, the evaporation temperature of -100 ℃ or less forms a temperature of an appropriate level to implement the temperature. Therefore, preferably, the low temperature refrigerant according to the present embodiment is characterized by using ethylene having an evaporation temperature of less than -100 ° C based on 1 bar.

As described above, even if the high temperature refrigerant is used butane (N-Butane) and the low temperature refrigerant by using ethylene (Ethylene) to achieve a deep temperature, to meet the discharge pressure range of the domestic compressor 110 It needs to be mixed in an appropriate weight ratio.

In this embodiment, a number of experiments are repeated to propose a proportion of the mixed refrigerant satisfying the discharge pressure range of the domestic compressor 110. In one example, the butane (N-Butane) is determined in the range of 80% to 85% by weight, the ethylene (Ethylene) may be determined in the range of 15% to 20% by weight.

In detail, the results of several repeated experiments are presented.

Indoor temperature (32 ℃)
N-BUTANE / ETHYLENE (wt%)	70/30	75/25	80/20	85/15	90/10
Discharge pressure (bar)	39.1	36.2	24.3	22.9	21.4
Suction pressure (bar)	1.7	1.5	1.18	1.09	0.94
Discharge temperature (℃)	116.9	111.2	105.4	101.3	98.6
Temperature performance (℃)	-79.8	-74.6	-68.3	-62.9	-55.8

[Table 3] presented above shows the results of experiments by varying the weight percentage ratio of butane (N-Butane) and ethylene (Ethylene) under the condition that the ambient temperature (room temperature) is 32 ℃.

If the above results are interpreted, the maximum discharge pressure, minimum suction pressure and maximum discharge temperature of the compressor are increased when the weight% of butane (N-Butane) is relatively increased in the mixed refrigerant of butane (N-Butane) and ethylene (Ethylene). Decreases, and the temperature performance, that is, the temperature value of the storage compartment implemented in the deep freezer, increases.

As described above, in order to satisfy the operating pressure and the temperature range of the domestic compressor 110, the maximum discharge pressure must be 25 bar or less, the maximum discharge temperature is 120 ° C. or less, and the minimum suction pressure must be 1 bar or more.

The ratio of butane (N-Butane) and ethylene (Ethylene) satisfying these conditions forms a weight percentage ratio of 80: 20 ~ 85: 15. And within such a weight% range, the temperature of the storage compartment which can exhibit the performance required for a deep freezer, for example, a value of -60 degrees C or less can be formed.

Indoor temperature (38 ℃)
N-BUTANE / ETHYLENE (wt%)	70/30	75/25	80/20	85/15	90/10
Discharge pressure (bar)	40.8	38.3	24.8	23.6	22.2
Suction pressure (bar)	1.9	1.6	1.25	1.14	0.98
Maximum discharge temperature (℃)	121.3	118.4	108.3	103.6	101.8
Temperature performance (℃)	-76.5	-72.4	-66.7	-61.9	-53.2

[Table 4] presented above shows the results of experiments by varying the weight ratio of butane (N-Butane) and ethylene (Ethylene) under the condition that the ambient temperature (room temperature) is 38 ℃.

If the above results are interpreted, the maximum discharge pressure, minimum suction pressure and maximum discharge temperature of the compressor are increased when the weight% of butane (N-Butane) is relatively increased in the mixed refrigerant of butane (N-Butane) and ethylene (Ethylene). Decreases, and the temperature performance, that is, the temperature value of the storage compartment implemented in the deep freezer, increases.

As described above, in order to satisfy the operating pressure and the temperature range of the domestic compressor 110, the maximum discharge pressure must be 25 bar or less, the maximum discharge temperature is 120 ° C. or less, and the minimum suction pressure must be 1 bar or more.

The ratio of butane (N-Butane) and ethylene (Ethylene) satisfying these conditions forms a weight percentage ratio of 80: 20 ~ 85: 15. And within such a weight% range, the temperature of the storage compartment which can exhibit the performance required for a deep freezer, for example, a value of -60 degrees C or less can be formed.

In summary, for the deep-temperature freezer 10 employing the home compressor 110, in order to achieve the desired performance, the ratio of butane (N-Butane) and ethylene (Ethylene) is a weight of 80: 20 ~ 85: 15 Refrigerants mixed to form% percentage values can be used.

FIG. 5 shows a result of experiments in which a mixed refrigerant is formed such that the ratio of butane (N-Butane) and ethylene is 83:17, and the storage chamber having a predetermined volume is cooled while increasing the amount of refrigerant. .

In detail, it is understood as a graph showing the temperature of the mixed refrigerant sucked into the compressor 110, that is, the suction pipe temperature, the temperature of the storage chamber to be cooled, and the amount of energy consumed by the operation of the deep-temperature freezer as the amount of the refrigerant increases.

As the amount of the mixed refrigerant increases, the suction pipe temperature tends to decrease little by little, the temperature of the storage compartment also decreases, and the amount of energy consumed gradually increases.

According to FIG. 5, in order to have a desired temperature performance of the deep freezer, that is, a value of −60 ° C. or less, the amount of the mixed refrigerant needs to be filled at least 80 g. Of course, depending on the volume of the storage compartment, the amount of the mixed refrigerant may vary.

With reference to FIG. 1 and FIG. 3, the structure of a cycle and the change of a physical property value are demonstrated. 3 shows a Ph diagram, and the portion indicated by a dotted line indicates a refrigeration cycle in which a plurality of heat exchangers 210 and 250 according to the present embodiment are not provided as a prior art, and the portion indicated by a solid line is configured according to the present embodiment. The refrigeration cycle by

In detail, the P-h diagram shows a number of isotherms. The isotherm includes T2 (T2 '), T3, T4, T5, and T7. The temperature value according to the isotherm may satisfy the following relation, that is, T2 (T2 ')> T7> T3> T5> T4. For example, T2 (T2 ') may be formed in the range of 35 ~ 40 ℃, T7 is 30 ~ 35 ℃, T3 is 8 ~ 13 ℃, T5 is about -60 ℃, T4 is about -80 ℃.

The deep-temperature freezer 10 according to the first embodiment of the present invention further includes a condenser 120 which is installed at the outlet side of the compressor 110 and condenses the mixed refrigerant discharged from the compressor 110. . The deep-temperature freezer 10 includes a dryer 130 installed at an outlet side of the condenser 120 to filter out water or foreign substances from the refrigerant condensed in the condenser 120.

The deep-temperature freezer 10 further includes an expansion device 140 installed at the outlet side of the dryer 130 to reduce the refrigerant condensed in the condenser 120. For example, the expansion device 140 may include a capillary tube. The deep freezer 10 further includes a condensation pipe 161 extending from the outlet side of the condenser 120 to the expansion device 140. The dryer 130 may be installed in the condensation pipe 161.

The deep-temperature freezer 10 further includes an evaporator 150 installed at an outlet side of the expansion device 140 to evaporate the refrigerant decompressed in the expansion device 140. In addition, the deep freezer 10 further includes a suction pipe 165 extending from the outlet side of the evaporator 150 to the suction side of the compressor 110.

Cooling air generated while the mixed refrigerant passes through the compressor 110, the condenser 120, the expansion device 140, and the evaporator 150 may be supplied to the storage compartment provided in the deep freezer 10.

The deep-temperature freezer 10 further includes a plurality of heat exchangers 210 and 250 for improving the operating efficiency of the deep-freezer 10. The plurality of heat exchangers 210 and 250 include a first heat exchanger 210 for performing heat exchange between the refrigerant flowing through the condensation pipe 161 and the refrigerant flowing through the suction pipe 165.

In detail, the first heat exchanger 210 may include a first suction heat exchanger 211 and a condensation heat exchanger 213 that performs heat exchange with the first suction heat exchanger 211. The first suction heat exchanger 211 may constitute at least a portion of the suction pipe 165, and the condensation heat exchanger 213 may constitute at least a portion of the condensation pipe 161.

The first suction heat exchanger 211 and the condensation heat exchanger 213 may be configured to contact each other. For example, the first suction heat exchanger 211 and the condensation heat exchanger 213 may be coupled by soldering. When heat exchange is performed between the first suction heat exchanger 211 and the condensation heat exchanger 213, a low temperature refrigerant flowing through the first suction heat exchanger 211 flows through the condensation heat exchanger 213. The refrigerant of can be cooled.

Therefore, the condensation pressure of the refrigerating cycle is lowered, whereby the discharge pressure of the compressor 110 can be reduced. In addition, as the discharge pressure of the compressor 110 is reduced, operation reliability of the domestic compressor 110 may be improved and noise may be reduced as described above.

In addition, since the endotherm of the refrigerant flowing through the first suction heat exchanger 211 may be made, the ratio of the liquid refrigerant contained in the refrigerant, that is, the ineffective cooling power may be reduced. In addition, inflow of the liquid refrigerant into the compressor 110 may be prevented.

In detail, referring to FIG. 3, the state of the refrigerant (point 1) compressed in the compressor 110 represents point 2 after passing through the condenser 120. Then, the refrigerant is condensed while passing through the condensation heat exchanger 213 (heat amount Q1), and as a result, the condensation temperature is lowered from T2 to T3 and the condensation pressure is formed to Pd.

On the other hand, in the prior art, the refrigerant compressed in the compressor condenses only in the condenser. At this time, the state of the compressed refrigerant represents point 1 ', and after passing through the condenser, the state of the refrigerant represents point 2'. That is, compared with the present invention, the condensation pressure indicates Pd 'higher than the Pd, and the condensation temperature indicates T2' higher than the T3. Here, T2 'has the same temperature value as T2.

As a result, the refrigerant passing through the condenser 120 is heat-exchanged in the first heat exchanger 210, whereby the condensation pressure Pd is lowered by ΔP than the conventional condensing pressure beam Pd ', and the condensation temperature T3. It can be seen that the lower than the condensation temperature (T2 ') of the prior art.

In addition, the refrigerant passing through the first suction heat exchange part 211 may undergo a process of endotherming and evaporating from the refrigerant passing through the condensation heat exchange part 213 (point 6-> 7, heat quantity Q1 ').

The ineffective cold power is a cold power of a refrigerant having a temperature higher than the temperature of cold air to be supplied to the deep storage compartment, for example, -60 ° C. or more, and is understood to be useless cold power that is difficult to be supplied to the deep storage compartment. That is, in the P-h diagram, since the temperature of T5 is about -60 ° C, it can be understood that the cooling force of the refrigerant forming the temperature of T5 to T7 is an ineffective cooling force.

As a result, some of the ineffective cooling force may be used to cool the condensation heat exchanger 213 of the first heat exchanger 210 through the first suction heat exchanger 211. In this process, the specific gravity of the liquid refrigerant may decrease while the refrigerant passing through the first suction heat exchange unit 211 is evaporated.

The plurality of heat exchangers 210 and 250 include a second heat exchanger 250 for performing heat exchange between the refrigerant flowing through the expansion device 140 and the refrigerant flowing through the suction pipe 165.

The first heat exchanger 210 may be installed at the outlet side of the second heat exchanger 250 based on the flow direction of the refrigerant flowing through the suction pipe 165. In addition, the second heat exchanger 250 may be installed at the outlet side of the first heat exchanger 210 based on the flow direction of the refrigerant flowing through the condensation pipe 161.

In detail, the second heat exchanger 250 includes an expansion for performing heat exchange with the second suction heat exchanger 251 and the second suction heat exchanger 251 provided on one side of the first suction heat exchanger 211. Device 140 may be included. The second suction heat exchanger 251 may constitute at least a portion of the suction pipe 165.

The second suction heat exchanger 251 and the expansion device 140 may be configured to contact each other. For example, the second suction heat exchanger 251 and the expansion device 140 may be coupled by soldering.

When heat exchange is performed between the second suction heat exchanger 251 and the expansion device 140, a low temperature refrigerant flowing through the second suction heat exchanger 251 flows through the expansion device 140. Can be cooled. Therefore, the refrigerant is decompressed in the course of passing through the expansion device 140, it is possible to reduce the tendency that the dryness increases in the decompression process.

That is, when the refrigerant passes through the expansion device 140, the pressure and temperature of the refrigerant may be lowered, and the ratio of the gaseous refrigerant in the refrigerant may be increased. The gaseous refrigerant has a bad effect on the evaporation performance of the evaporator 150, and if the proportion of the gaseous refrigerant is increased, the proportion of the liquid refrigerant that can be evaporated decreases, so that the evaporation performance may be deteriorated.

As a result, since the refrigerant passing through the expansion device 140 may be cooled through the second heat exchanger 250, the ratio of the liquid refrigerant at the inlet side of the evaporator 150 may be increased, thereby improving the evaporation performance. Appears.

The first heat exchanger 210 may be installed at the outlet side of the second heat exchanger 250 based on the refrigerant flow direction in the suction pipe 165. In other words, the first suction heat exchanger 211 may be installed at an outlet side of the second suction heat exchanger 251.

Therefore, the refrigerant passing through the evaporator 150 is heat-exchanged in the second heat exchanger 250 and then heat-exchanged in the first heat exchanger 210, thereby increasing the dryness and reducing the ineffective cooling power. In addition, the suction temperature may increase as the dryness increases, and as the suction temperature increases, the suction temperature condition of the household compressor 110 may be easily met.

In detail, referring to FIG. 3, the refrigerant passing through the first heat exchanger 210 exchanges heat with the second suction heat exchanger 251 while passing through the expansion device 140 (heat quantity Q2), and as a result, the refrigerant. The temperature of is lowered from T3 to T4, and the pressure of the refrigerant can be lowered from Pd to Ps (the state of the refrigerant moves from point 3 to 4). In detail, from a thermodynamic point of view, it is understood that when the refrigerant exchanges heat with the second suction heat exchanger 251 while passing through the expansion device 140, the state of the refrigerant is changed to the point 3-> 3 '-> 4. As a result, the state of the refrigerant moves from point 3 to 4. As a result, since the refrigerant heat-exchanged in the first heat exchanger 210 is further heat-exchanged in the second heat exchanger 250, the pressure and temperature of the refrigerant may be lowered.

The refrigerant passing through the expansion device 140 of the second heat exchanger 250 is introduced into the evaporator 150 and evaporated. After the refrigerant passes through the evaporator 150, the state changes from point 4 to 5. The temperature T4 at point 4 is about -80 ° C and the temperature T5 at point 5 represents about -60 ° C. Thus, the refrigerant cooling force in the sections 4 to 5 can serve as an effective cooling force sufficient to cool the cold air to be supplied to the storage compartment of the deep freezer.

The refrigerant passing through the evaporator 150 passes through the second suction heat exchanger 251 of the second heat exchanger 250, and is endothermic to evaporate from the refrigerant passing through the expansion device 140 (point 5 -> 6, calories Q2 '). The coolant cooling power in the sections 5 to 6 is a cooling force corresponding to a temperature of -60 ° C or higher, and acts as an ineffective cooling force.

However, the calorific value Q2 ′ may be used to cool the expansion device 140 of the second heat exchanger 250 through the second suction heat exchanger 251. In this process, while the refrigerant passing through the second suction heat exchange unit 251 is evaporated, the specific gravity of the liquid refrigerant may decrease.

In summary, the Q1 'and Q2' are ineffective cooling power, but are used to cool the condensation heat exchanger 213 of the first heat exchanger 210 and the expansion device 140 of the second heat exchanger 250. Can be. In this process, the refrigerant passing through the first and second suction heat exchangers 211 and 251 may reduce the specific gravity of the liquid refrigerant while evaporating.

The deep-temperature freezer 10 further includes a heat exchanger connection pipe 260 disposed between the first heat exchanger 210 and the second heat exchanger 250. The heat exchanger connection pipe 260 constitutes a part of the condensation pipe 161 and may be configured to connect the first heat exchanger 210 and the second heat exchanger 250.

Since the first heat exchanger 210 and the second heat exchanger 250 are spaced apart from each other by the heat exchanger connection pipe 260, heat exchange is prevented between the first and second heat exchangers 210 and 250. Can be. That is, heat exchange may be prevented between the condensation heat exchanger 213 and the expansion device 140.

If heat exchange occurs between the condensation heat exchanger 213 and the expansion device 140, a problem may occur in which the cooling effect of the expansion device 140 is reduced. Therefore, in this embodiment, the heat exchanger connection pipe 260 is disposed between the first and second heat exchangers 210 and 250 to solve this problem.

4 is a result of the change in energy consumption and compressor suction temperature according to the length of the first heat exchanger 210, that is, the length of the first suction heat exchanger 211 or the condensation heat exchanger 213. Show the value.

As the length of the first heat exchanger 210 increases, that is, as the amount of heat exchange in the first heat exchanger 210 increases, the endotherm of the refrigerant sucked into the compressor 110 increases, so that the temperature of the compressor 110 increases. The suction temperature will increase. Then, the energy consumption according to the operation of the deep-temperature freezer 10 is reduced.

Based on the operating conditions of the domestic compressor 110 according to the present embodiment, the suction temperature Ts of the compressor 110 may satisfy the following equation with respect to the ambient temperature (room temperature, To).

To-5 ℃ <Ts <To + 5 ℃

As the suction temperature Ts of the compressor 110 increases, suction of the liquid refrigerant into the compressor 110 may be prevented, and an ineffective cooling force may be reduced. However, if the suction temperature Ts of the compressor 110 is too high, a problem may occur in which the discharge temperature or the discharge pressure of the compressor 110 is too high. As a result, in order to form the operating conditions of the household compressor 110 and the compressor discharge temperature at an appropriate level according to the present embodiment, the suction temperature Ts of the compressor 110 may satisfy the above equation. .

Referring to FIG. 4, the length of the first heat exchanger 210 to satisfy the suction temperature Ts of the compressor 110 may be about 3.5 to 5 m. That is, when the length condition of the first heat exchanger 210 is satisfied, the operation condition of the domestic compressor 110 according to the present embodiment may be satisfied, and the operation reliability of the compressor may be improved.

Meanwhile, the pipe diameter of the condensation heat exchanger 213 may be larger than the pipe diameter of the expansion device 140. For example, the pipe diameter of the condensation heat exchanger 213 may be formed in the range of 3.5 to 4.5 times the pipe diameter of the expansion device (140). In detail, the pipe diameter of the condensation heat exchanger 213 may be 3.5 mm, and the pipe diameter of the expansion device 140 may be 0.8 mm.

The refrigerant passing through the condensation heat exchanger 213 should be condensed. On the other hand, the refrigerant passing through the expansion device 140 should be reduced in pressure. In fact, referring to the P-h diagram of FIG. 3, the dryness of the exit state (point 4) of the expansion device 140 is formed higher than the dryness of the inlet state (point 3). That is, in the process of passing the refrigerant through the expansion device 140, vaporization is performed with decompression.

In summary, in the expansion device 140, since the pressure of the refrigerant is reduced, the pipe diameter may be reduced to increase the flow rate of the refrigerant, and thus the pressure of the refrigerant may be reduced. On the other hand, if the pipe diameter of the condensation heat exchanger 213 is too small, the condensation heat exchanger 213 acts as a resistance to the refrigerant, so that the refrigerant flow rate decreases and the refrigerant pressure decreases, while the refrigerant condensation May be limited.

Therefore, in the present embodiment, the pipe diameter of the condensation heat exchange part 213 is sufficiently larger than the pipe diameter of the expansion device 140 so that the condensation heat exchange part 213 does not act as a resistance to the refrigerant. It is characterized by. In this case, a relatively bulky gaseous refrigerant may easily flow through the condensation heat exchanger 213 and may be sufficiently condensed while heat exchange is performed in the first heat exchanger 210.

The following describes the second to fifth embodiments of the present invention. Since these embodiments differ only in some configurations compared to the first embodiment, the differences are mainly described. For the same parts as those of the first embodiment, the description of the first embodiment and reference numerals are used.

6 is a view showing a refrigeration cycle provided in the freezer temperature according to the second embodiment of the present invention.

Referring to FIG. 6, the deep-temperature freezer 10a according to the second embodiment of the present invention includes the compressor 110, the condenser 120, the dryer 130, the expansion device 140, and the condenser 120. Condensation pipe 161 extending to the expansion device 140 is included.

The deep-temperature freezer 10a exchanges heat between the refrigerant passing through the first heat exchanger 210 and the expansion device 140 to perform heat exchange between the condensation refrigerant and the suction refrigerant to the compressor 110 and the suction refrigerant. Further included is a second heat exchanger 250 to perform the.

The description of the above configurations uses the description of the first embodiment.

The deep freezer 10a further includes a plurality of evaporators 151 and 152 for evaporating the refrigerant depressurized by the expansion device 140.

The plurality of evaporators 151 and 152 may include a first evaporator 151 installed at an outlet side of the expansion device 140 and a second evaporator 152 installed at an outlet side of the first evaporator 151. . The first and second evaporators 151 and 152 may be connected in series.

The deep freezer 10a may include a plurality of storage compartments corresponding to the plurality of evaporators 151 and 152. The plurality of storage rooms may include a cryogenic storage room of about −60 ° C. or less and a freezer of about −20 ° C. For example, the cold air generated by the first evaporator 151 may be supplied to the cryogenic storage chamber, and the cold air generated by the second evaporator 152 may be supplied to the freezing chamber.

The second heat exchanger 250 may be installed at the outlet side of the second evaporator 152, and the first heat exchanger 210 may be installed at the outlet side of the second heat exchanger 250. The refrigerant evaporated in the second evaporator 152 is endothermic while passing through the second heat exchanger 250 and the first heat exchanger 210. Accordingly, the temperature of the refrigerant sucked into the compressor 110 increases and the dryness is increased. May be raised.

7 is a view showing a refrigeration cycle provided in the freezer temperature according to the third embodiment of the present invention.

Referring to FIG. 7, the deep freezer 10b according to the third embodiment of the present invention includes the compressor 110, the condenser 120, the dryer 130, the expansion device 140, and the condenser 120. Condensation pipe 161 extending to the expansion device 140 is included.

The expansion device 140 includes two expansion devices. The two expansion devices are connected in parallel with the first expansion device 141 and the first expansion device 141 through which at least a portion of the refrigerant flowing through the condensation pipe 161 may flow, and the condensation pipe ( A second expansion device 143 is included through which another portion of the refrigerant flowing in 161 can flow.

In the condensation pipe 161, a valve device for introducing a refrigerant flowing through the condensation pipe 161 into at least one expansion device 143 of the first expansion device 141 and the second expansion device 143. 170 may be installed. For example, the valve device 170 may include a three-way valve. The condensation pipe 161 is connected to the inlet of the three-way valve, and the first and second expansion devices 141 and 143 may be connected to the two outlets of the three-way valve, respectively.

The deep freezer 10b includes a first evaporator 151a connected to an outlet side of the first expansion device 141 and a second evaporator 152a connected to an outlet side of the second expansion device 143. More included. In the deep freezer 10b, a first evaporation pipe 181 extending from the first outlet of the valve device 170 to the first evaporator 151a and a second outlet of the valve device 170 are provided. A second evaporation pipe 183 extending from the portion to the second evaporator 152a is further included.

The first evaporation pipe 181 and the second evaporation pipe 183 may be laminated at the lamination part 185. The lamination part 185 may be one point of the first evaporation pipe 181 or the second evaporation pipe 183. By such a configuration, the first evaporator 151a and the second evaporator 152a may be connected in parallel.

The first evaporating pipe 181 may be provided with a check valve 158 for guiding the one-way flow of the refrigerant in the first evaporating pipe 181. By the check valve 158, the flow of cold water from the lamination part 185 toward the first evaporator 151a may be restricted. As a result, the refrigerant passing through the second evaporator 152a may be prevented from entering the first evaporator 151a through the lamination part 185.

Under the control of the valve device 170, at least one of the first and second evaporators 151a and 152a may be operated. When the first outlet of the two outlets of the valve device 170 is opened and the second outlet is closed, only the refrigerant flow from the valve device 170 to the first evaporator 151a may be generated.

On the other hand, when the second outlet of the two outlets of the valve device 170 is opened and the first outlet is closed, only the refrigerant flow from the valve device 170 to the second evaporator 151a may be generated. . Of course, when both outlets of the valve device 170 are opened, the refrigerant flowing into the valve device 170 branches and flows to the first and second evaporators 151a and 152a through the first and second outlets. Can be.

The deep freezer 10b may include a plurality of storage compartments corresponding to the plurality of evaporators 151a and 152a. The plurality of storage compartments may include two cryogenic storage compartments of -60 ° C or less. As another example, the plurality of storage rooms may include a cryogenic storage room of about −60 ° C. or less and a freezer of about −20 ° C.

The refrigerant passing through the first evaporator 151a or the second evaporator 152a may pass through the second heat exchanger 250a. The second heat exchanger 250a includes at least a portion of the first expansion device 141, the second expansion device 143, and the suction pipe 165, that is, the second suction heat exchanger 251 described in the first embodiment. ) May be included.

The first and second expansion devices 141 and 143 and the second suction heat exchanger 251 may be disposed to contact each other. For example, the first and second expansion devices 141 and 143 and the second suction heat exchanger 251 may be coupled by soldering.

A first heat exchanger 210a may be installed at the outlet side of the second heat exchanger 250a. The first heat exchanger 210a includes at least a portion of the condensation pipe 161, that is, at least a portion of the condensation heat exchanger 213 and the suction pipe 165 described in the first embodiment, that is, the first suction. The heat exchanger 211 may be included. Description of the operation of the first heat exchanger 210a and the second heat exchanger 250a uses the description of the first embodiment.

8 is a view showing a refrigerating cycle provided in a deep-temperature freezer according to a fourth embodiment of the present invention.

Referring to FIG. 8, the deep freezer 10c according to the fourth embodiment of the present invention includes the compressor 110, the condenser 120, the dryer 130, the expansion device 140, and the condenser 120. Condensation pipe 161 extending to the expansion device 140 is included.

In the deep freezer (10c), a heat exchange between the refrigerant passing through the first heat exchanger (210) and the expansion device (140) for performing heat exchange between the condensation refrigerant and the suction refrigerant to the compressor (110) and the suction refrigerant is performed. Further included is a second heat exchanger 250 to perform the.

The description of the above configurations uses the description of the first embodiment.

The deep freezer 10c further includes a plurality of evaporators 151b, 152b, and 153b for evaporating the refrigerant decompressed in the expansion device 140.

The plurality of evaporators 151b, 152b and 153b may include a first evaporator 151b provided at an outlet side of the expansion device 140 and a second evaporator provided at an outlet side of the first evaporator 151b ( 152b) and a third evaporator 153b installed at the outlet side of the second evaporator 152b. The first, second, and third evaporators 151b, 152b, and 153b may be connected in series.

The deep freezer 10c may include a plurality of storage compartments corresponding to the plurality of evaporators 151b, 152b, and 153b. The plurality of storage rooms may include a cryogenic storage room of -60 ° C or less, a freezer of about -20 ° C, and a refrigerating room of 0 to 5 ° C. For example, the cold air generated by the first evaporator 151b may be supplied to the cryogenic storage chamber, the cold air generated by the second evaporator 152b may be supplied to the freezing chamber, and the third evaporator 153b. The cold air generated in) may be supplied to the refrigerating compartment.

The second heat exchanger 250 may be installed at the outlet side of the third evaporator 153b, and the first heat exchanger 210 may be installed at the outlet side of the second heat exchanger 250. The refrigerant evaporated in the second evaporator 152 is endothermic while passing through the second heat exchanger 250 and the first heat exchanger 210. Accordingly, the temperature of the refrigerant sucked into the compressor 110 increases and the dryness is increased. May be raised. The related description uses the description of the first embodiment.

9 is a view showing a refrigeration cycle provided in a deep-temperature freezer according to a fifth embodiment of the present invention.

Referring to FIG. 9, the deep-temperature freezer 10d according to the fifth embodiment of the present invention includes two independent refrigeration cycles. The configurations of the two independent refrigeration cycles are identical to each other.

The two refrigeration cycles include a first refrigeration cycle. In detail, the first refrigeration cycle, the first compressor (110a), the first condenser (120a), the first dryer (130a), the first expansion device (140a), the first condensation pipe (161a), the first evaporator ( 150a), a first suction pipe 165a, a second heat exchanger 250b, and a first heat exchanger 210b. Description of these configurations and operations is the same as that of the first embodiment.

The two refrigeration cycles include a second refrigeration cycle. In detail, the first refrigeration cycle, the second compressor 110b, the second condenser 120b, the second dryer 130b, the second expansion device 140b, the second condensation pipe 161b, the second evaporator ( 150b), a second suction pipe 165b, a fourth heat exchanger 250c, and a third heat exchanger 210c. Description of these configurations and operations is the same as that of the first embodiment.

According to this embodiment, two refrigeration cycles independent of each other may be operated to cool the plurality of storage compartments provided in the deep freezer 10d. The plurality of storage compartments may include two cryogenic storage compartments of -60 ° C or less. The cold air generated in the first refrigeration cycle may cool the first cryogenic storage chamber, and the cold air generated in the second refrigeration cycle may cool the second cryogenic storage chamber.

According to an embodiment of the present invention, the refrigerant condensed in the condenser passes through a plurality of heat exchangers before entering the evaporator, thereby lowering the condensation pressure of the refrigeration cycle and preventing rise in dryness when the condensed refrigerant passes through the expansion device. As it can be seen, the industrial applicability is remarkable.

Claims (20)

1. A compressor for compressing two or more mixed refrigerants;

   A condenser for condensing the mixed refrigerant compressed by the compressor;

   An expansion device for depressurizing the mixed refrigerant condensed in the condenser;

   An evaporator for evaporating the reduced pressure of the mixed refrigerant in the expansion device;

   A condensation pipe extending from the outlet side of the condenser to the expansion device to guide the flow of the mixed refrigerant;

   A suction pipe extending from the outlet side of the evaporator to the compressor to guide suction of the mixed refrigerant into the compressor; And

   And a plurality of heat exchangers installed in the suction pipe and performing heat exchange of the mixed refrigerant sucked into the compressor.
2. The method of claim 1,

   The plurality of heat exchangers include a first heat exchanger,

   In the first heat exchanger,

   A first suction heat exchanger for guiding the flow of the mixed refrigerant sucked into the compressor; And

   And a condensation heat exchanger configured to perform heat exchange with the first suction heat exchanger and to guide the flow of the condensation pipe.
3. The method of claim 2,

   Pipe diameter of the condensation heat exchanger,

   Deep freezer, characterized in that formed larger than the pipe diameter of the expansion device.
4. The method of claim 2,

   The plurality of heat exchangers include a second heat exchanger,

   In the second heat exchanger,

   A second suction heat exchanger provided at one side of the first suction heat exchanger to guide the flow of the mixed refrigerant sucked into the compressor; And

   Deep freezer comprising the expansion device for performing heat exchange with the second suction heat exchange unit.
5. The method of claim 4, wherein

   The first suction heat exchange unit and the condensation pipe, or

   The second suction heat exchanger and the expansion device,

   Deep freezer, characterized in that to perform heat exchange in contact with each other.
6. The method of claim 4, wherein

   A heat exchanger connection pipe disposed between the first and second heat exchangers to prevent heat exchange between the expansion device and the condensation heat exchange unit;

   And the first heat exchanger and the second heat exchanger are spaced apart from each other by the heat exchanger connection pipe.
7. The method of claim 4, wherein

   And the first heat exchanger is installed at an outlet side of the second heat exchanger based on a flow direction of the refrigerant flowing through the suction pipe.
8. The method of claim 4, wherein

   And the second heat exchanger is installed at an outlet side of the first heat exchanger based on a flow direction of the refrigerant flowing through the condensation pipe.
9. The method of claim 1,

   The evaporator includes a first evaporator and a second evaporator connected in series with each other,

   And the second evaporator is installed at an outlet side of the first evaporator.
10. The method of claim 1,

    The evaporator includes a first evaporator and a second evaporator connected in parallel to each other,

    The expansion device, a deep freezer including a first expansion device installed on the inlet side of the first evaporator and a second expansion device installed on the inlet side of the second evaporator.
11. The method of claim 1,

    The evaporator,

    A first evaporator installed at an outlet side of the expansion device;

    A second evaporator connected in series with the outlet side of the first evaporator; And

    And a third evaporator connected in series to the outlet side of the second evaporator.
12. The method of claim 1,

    In the mixed refrigerant,

    High temperature refrigerant selected from any one of butane (N-Butane), 1-butene (1-Butene), and isobutane; And

    Deep freezer containing a low-temperature refrigerant composed of ethylene (Ethylene).
13. The method of claim 12,

    The butane (N-Butane) is determined in the range of 80% to 85% by weight, Ethylene (Ethylene) is a deep freezer, characterized in that determined in the range of 15% to 20% by weight.
14. The method of claim 12,

    The compressor is operated at a set pressure range,

    In the set pressure range,

    The maximum discharge pressure of the compressor is included in the range of 25 bar or less,

    Deep freezer including a range of the minimum suction pressure of the compressor is more than 1 bar (bar).
15. The method of claim 12,

    The compressor is operated within a set temperature range,

    In the set temperature range,

    Deep freezer including the range that the maximum discharge temperature of the compressor is 120 ℃ or less.
16. The method of claim 12,

    In the deep freezer,

    A deep freezer containing a reservoir having a temperature value of less than -60 ℃.
17. The method of claim 2,

    The first suction heat exchanger or the condensation heat exchanger is a length freezer, characterized in that formed in the range of 3.5 ~ 5m.
18. The method of claim 3, wherein

    Pipe diameter of the condensation heat exchanger,

    Deep freezer, characterized in that formed in the range of 3.5 to 4.5 times the diameter of the pipe of the expansion device.
19. The method of claim 10,

    The first and second expansion device and the suction pipe is a deep freezer, characterized in that the heat exchange is coupled to each other.
20. The method of claim 1,

    Two independent refrigeration cycles are driven

    And each of the independent refrigeration cycles includes the compressor, the condenser, the expansion device, the evaporator and the plurality of heat exchangers.

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