CN111536721A - Defrosting method and device adopting medium specific enthalpy vapor-liquid mixture refrigerant - Google Patents
Defrosting method and device adopting medium specific enthalpy vapor-liquid mixture refrigerant Download PDFInfo
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- 238000010257 thawing Methods 0.000 title claims abstract description 181
- 239000003507 refrigerant Substances 0.000 title claims abstract description 130
- 239000007788 liquid Substances 0.000 title claims abstract description 127
- 239000000203 mixture Substances 0.000 title claims abstract description 94
- 238000000034 method Methods 0.000 title claims abstract description 32
- 230000007246 mechanism Effects 0.000 claims abstract description 29
- 238000006243 chemical reaction Methods 0.000 claims abstract description 18
- 238000005057 refrigeration Methods 0.000 claims description 52
- 238000001816 cooling Methods 0.000 claims description 23
- 230000008020 evaporation Effects 0.000 claims description 12
- 238000001704 evaporation Methods 0.000 claims description 12
- 238000002844 melting Methods 0.000 claims description 7
- 230000008018 melting Effects 0.000 claims description 7
- 230000009466 transformation Effects 0.000 claims description 7
- 238000002156 mixing Methods 0.000 claims description 4
- 230000001131 transforming effect Effects 0.000 claims description 3
- 230000008901 benefit Effects 0.000 abstract description 4
- 230000008569 process Effects 0.000 description 14
- 238000009833 condensation Methods 0.000 description 10
- 230000005494 condensation Effects 0.000 description 10
- 238000010521 absorption reaction Methods 0.000 description 8
- 230000006835 compression Effects 0.000 description 5
- 238000007906 compression Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000009467 reduction Effects 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B47/00—Arrangements for preventing or removing deposits or corrosion, not provided for in another subclass
- F25B47/02—Defrosting cycles
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2347/00—Details for preventing or removing deposits or corrosion
- F25B2347/02—Details of defrosting cycles
Abstract
The invention discloses a defrosting method and a defrosting device adopting a vapor-liquid mixture refrigerant with medium specific enthalpy. The defrosting device is integrated in a refrigerating system and comprises a form conversion mechanism for converting a refrigerant in the refrigerating system into a vapor-liquid mixture refrigerant and a defrosting pipeline for conveying the vapor-liquid mixture to an evaporator to be defrosted, wherein the defrosting pipeline is connected to a main refrigerating pipeline of the refrigerating system in a bypassing manner. The invention adopts the vapor-liquid mixture with medium specific enthalpy as the defrosting medium to melt the frosting on the evaporator, and has the advantages of easy control, higher defrosting efficiency and the like.
Description
Technical Field
The invention relates to a defrosting technology of a refrigerating system, in particular to a defrosting method and a defrosting device adopting a vapor-liquid mixture refrigerant with medium specific enthalpy.
Background
In the operation process of the refrigeration system, when the evaporation temperature is lower than 0 ℃, the phenomenon of frosting can occur on the evaporator, so that the heat exchange efficiency and the refrigeration efficiency are reduced, and defrosting treatment is required.
The existing defrosting mode mainly comprises refrigerant defrosting and non-refrigerant defrosting, wherein the refrigerant defrosting adopts the working principle that the enthalpy value and the temperature of the refrigerant are increased by performing compression work through a compressor, the refrigerant with higher temperature and enthalpy value is conveyed to an evaporator to be melted, and the refrigerant serves as a defrosting medium and is used for releasing heat to melt and frosting.
Furthermore, the refrigerants commonly used as defrosting media are mainly gaseous refrigerants and liquid refrigerants, wherein the gaseous defrosting media can achieve relatively high defrosting efficiency, but in the actual defrosting process, because the specific enthalpy of the superheated gas is large, the moment of exiting defrosting is difficult to control accurately, that is, the defrosting time is difficult to control accurately, the phenomenon that the superheated gas carries out net heat release on a cooled object easily occurs, the phenomenon that the heat of compression work is transferred to air is difficult to avoid, and the operation efficiency of a refrigeration system is reduced. The defrosting medium for liquid defrosting is mainly high-pressure liquid refrigerant formed by condensing gas with high specific enthalpy through a condenser, and defrosting is performed by using the liquid refrigerant, although the problem similar to that of superheated gas defrosting does not exist, the specific enthalpy of the throttled liquid refrigerant is relatively small, the required flow is large, the defrosting efficiency is low, the time required for single defrosting is long, and the defrosting time interval is short.
Disclosure of Invention
The invention aims to overcome the problems and provide a defrosting method adopting a vapor-liquid mixture refrigerant with medium specific enthalpy, which adopts the vapor-liquid mixture with medium specific enthalpy as a defrosting medium to melt frosting on an evaporator, and has the advantages of easy control, high defrosting efficiency and the like.
Another object of the present invention is to provide a defrosting apparatus using a vapor-liquid mixture refrigerant with a medium specific enthalpy.
The purpose of the invention is realized by the following technical scheme:
a defrosting method adopting a vapor-liquid mixture refrigerant with medium specific enthalpy comprises the following steps:
the refrigerant in the refrigeration system is converted into a vapor-liquid mixture refrigerant through a form conversion mechanism, the vapor-liquid mixture refrigerant is conveyed to an evaporator to be defrosted through a defrosting pipeline, and the vapor-liquid mixture refrigerant is used as a defrosting medium to release heat to melt frosting on the evaporator.
In a preferred embodiment of the present invention, the conversion modes of the form conversion mechanism include liquid refrigerant endothermic conversion, gas refrigerant exothermic conversion, and liquid refrigerant/gas refrigerant mixture conversion.
Preferably, the gas refrigerant exothermal conversion mode is as follows: the gas refrigerant compressed by the compressor is cooled or depressurized through the cooling mechanism to form a gas-liquid mixture refrigerant.
In a preferred aspect of the present invention, in the defrosting operation, at least one evaporator is refrigerating; after the defrosting operation is finished, the refrigerant is conveyed downwards to the evaporator which is performing the refrigeration operation for evaporation. In the later evaporation process, the characteristics of the gas-liquid mixture with medium specific enthalpy are utilized: the heat absorption capacity is not less than the heat release capacity, and even if the heat is leaked to the outside in the defrosting process, the heat can be absorbed back equally through subsequent evaporation heat absorption, so that the refrigerating efficiency of the refrigerating system cannot be reduced. Of course, after the defrosting operation is finished, the refrigerant can be conveyed downwards to the liquid storage container for storage.
In a preferred embodiment of the present invention, the enthalpy of the vapor-liquid mixture refrigerant is greater than the enthalpy of the gas compressed by the compressor and discharged after the gas is completely condensed, and is less than or equal to the enthalpy of the refrigerant as a defrosting medium after the refrigerant is evaporated for cooling.
In a preferred embodiment of the present invention, the temperature of the vapor-liquid mixture refrigerant is higher than the melting temperature of frost on the surface of the evaporator to be defrosted and lower than the condensing temperature of the refrigeration system.
Preferably, when the frosting component is ice, the melting temperature is 0 ℃.
The defrosting device integrated in a refrigerating system comprises a form conversion mechanism for converting a refrigerant in the refrigerating system into a vapor-liquid mixture refrigerant and a defrosting pipeline for conveying the vapor-liquid mixture to an evaporator to be defrosted, wherein the defrosting pipeline is in bypass connection with a main refrigerating pipeline of the refrigerating system.
The working principle of the defrosting device adopting the vapor-liquid mixture refrigerant with the medium specific enthalpy is as follows:
when the refrigerant transformation device works, a (non-vapor-liquid mixed) refrigerant in a refrigeration system is transformed into a vapor-liquid mixture refrigerant with medium specific enthalpy through the form transformation mechanism, wherein the medium specific enthalpy mainly means that the defrosting condensation specific enthalpy of the vapor-liquid refrigerant is slightly smaller than the evaporation specific enthalpy of the defrosted refrigerant; and then the vapor-liquid mixture refrigerant (serving as a defrosting medium) is conveyed to the evaporator to be defrosted through the defrosting pipeline and is used for defrosting the evaporator.
In a preferred embodiment of the present invention, the form transforming mechanism includes a cooling mechanism for reducing enthalpy of the gas compressed by the compressor to form a vapor-liquid mixture.
In a preferred embodiment of the present invention, the head end of the defrosting pipe is an inlet end, the inlet end is connected between a condenser and an oil separator of the refrigeration system, and the tail end extends to an evaporator to be defrosted;
the cooling mechanism comprises a cooler arranged on the defrosting pipeline. Through above-mentioned structure, the access end of defrosting pipeline leads to the evaporimeter of treating the defrosting with high-temperature high-pressure gas, and at this in-process, the high-temperature high-pressure gas cooling is the vapour-liquid mixture by the cooler for vapour-liquid mixture carries out the defrosting as the medium of defrosting to the evaporimeter.
In a preferred embodiment of the present invention, the defrosting pipe is provided with two access ends, one of the access ends is connected between a condenser and an oil separator of the refrigeration system, and the other access end is connected behind the condenser of the refrigeration system;
the cooling mechanism comprises a cooler arranged on the defrosting pipeline and a condenser of the refrigerating system, and the cooler is positioned between connecting points of the two access ends. Through above-mentioned structure, two incoming ends of defrosting pipeline are respectively with the liquid after high-temperature high-pressure gas and the condensation let in the trunk line of defrosting pipeline, high-temperature high-pressure gas becomes the lower gas of enthalpy value (or vapour-liquid mixture) after the cooling of cooler, collects the back with the liquid after the condensation again, forms vapour-liquid mixture, and then leads to the evaporimeter department of waiting to defrost with vapour-liquid mixture, carries out the defrosting to the evaporimeter.
In a preferred embodiment of the present invention, the defrosting pipe is provided with two access ends, one of the access ends is connected between a condenser and an oil separator of the refrigeration system, and the other access end is connected behind the condenser of the refrigeration system;
the cooling mechanism is composed of a condenser of a refrigeration system. Through above-mentioned structure, in two incoming ends of defrosting pipeline let in the trunk line of defrosting pipeline with the liquid after high-temperature high-pressure gas and the condensation respectively, the liquid after high-temperature high-pressure gas and the condensation collects the back, forms vapour-liquid mixture, and then leads to the evaporimeter department of treating the defrosting with vapour-liquid mixture, carries out the defrosting to the evaporimeter.
In a preferred embodiment of the present invention, the access ends of the defrosting pipes are respectively provided with a flow control valve for controlling the flow rate of the refrigerant introduced into the pipes, so that the flow rate of the refrigerant is more stable. Specifically, when the defrosting pipeline is provided with two access ends, the flow of the two flow control valves is adjusted by combining different enthalpy values of two defrosting media (refrigerants), so that a vapor-liquid mixture is formed after the two defrosting media are converged.
In a preferred embodiment of the present invention, the defrosting pipe is provided with a pressure controller for adjusting the pressure of the defrosting medium in the pipe.
In a preferred embodiment of the present invention, the defrosting pipe is provided with a temperature sensor for detecting a temperature of the defrosting medium in the pipe.
Compared with the prior art, the invention has the following beneficial effects:
1. the defrosting method provided by the invention adopts a vapor-liquid mixture with medium specific enthalpy as a defrosting medium to melt frosting on the evaporator, and has the advantages of easiness in control, higher defrosting efficiency and the like.
2. The vapor-liquid mixture is used as a defrosting medium, so that the compression work is eliminated, the defrosting refrigerant always absorbs heat cleanly, and the defrosting condition is easy to control.
3. The specific enthalpy of defrosting of the vapor-liquid mixture is close to the specific enthalpy of evaporation, so the amount of refrigerant used for defrosting is less.
4. Compared with the defrosting of the gas refrigerant, the defrosting of the gas-liquid mixture belongs to a net heat absorption process, and the phenomenon of net heat release cannot be generated, so that the operation efficiency of the refrigerating system cannot be reduced.
5. Compared with liquid refrigerant defrosting, the refrigerant flow required by defrosting is greatly reduced (the flow of the liquid refrigerant is 10 times of that of the vapor-liquid mixture refrigerant), the time required by single defrosting is reduced, and the defrosting frequency is effectively reduced.
Drawings
Fig. 1 is a pressure-enthalpy diagram in which the refrigerant is located at positions respectively representing 1 an inlet of a compressor, 2 an inlet of a condenser, 3 an inlet of a throttling element (expansion valve), 4 an inlet of an evaporator which is in a cooling operation, 5 an outlet of a cooler, 6 an inlet of an evaporator to be defrosted, 8 an outlet of an evaporator to be defrosted, and 9 an inlet of an evaporator which is in a cooling operation.
Fig. 2 is a schematic configuration diagram of a first embodiment of the defrosting apparatus of the present invention applied to a refrigeration system, wherein a defrosting duct is indicated by a dotted line.
Fig. 3 is a schematic configuration diagram of a second embodiment of the defrosting apparatus of the present invention applied to a refrigeration system, wherein a defrosting duct is indicated by a dotted line.
Fig. 4 is a schematic configuration diagram of a third embodiment of the defrosting apparatus according to the present invention applied to a refrigeration system, wherein a defrosting duct is indicated by a dotted line.
Detailed Description
In order to make those skilled in the art understand the technical solutions of the present invention well, the following description of the present invention is provided with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.
Example 1
Referring to fig. 2, the defrosting apparatus using a vapor-liquid mixture refrigerant with a medium specific enthalpy in the present embodiment includes a form conversion mechanism for converting a refrigerant in a refrigeration system into a vapor-liquid mixture refrigerant, and a defrosting pipe 3 for delivering a vapor-liquid mixture to an evaporator to be defrosted, where the defrosting pipe is bypassed to a refrigeration pipe 4 of the refrigeration system. Specifically, the defrosting device in the present embodiment is integrated into a refrigeration system provided with two evaporators; of course, may be integrated in a refrigeration system having three, four or even more evaporators.
Referring to fig. 2, the form transforming mechanism includes a cooling mechanism for making the gas compressed by the compressor 1 form a vapor-liquid mixture by enthalpy.
Referring to fig. 1-2, the defrosting pipe 3 has a head end serving as an inlet end connected between a condenser 5 and an oil separator 6 of a refrigeration system, and a tail end extending to an evaporator 2(a) to be defrosted; the cooling mechanism comprises a cooler 7 arranged on the defrosting duct 3. Through the structure, the connecting end of the defrosting pipeline 3 leads high-temperature and high-pressure gas to the evaporator 2(a) to be defrosted, and in the process, the cooler 7 cools the high-temperature and high-pressure gas into a gas-liquid mixture, so that the gas-liquid mixture is used as a defrosting medium to defrost the evaporator. Further, referring to fig. 1, the high-temperature and high-pressure gas at the point 2 is cooled by a cooler 7 to form a vapor-liquid mixture at the point 5, and then throttling is performed, pressure is reduced to form a vapor-liquid mixture at the point 6, and the vapor-liquid mixture is introduced into an evaporator 2(a) to be defrosted to perform defrosting operation.
Referring to fig. 2, the inlet ends of the defrosting pipes 3 are provided with flow control valves 8 for controlling the flow of the refrigerant introduced into the pipes.
Referring to fig. 2, the defrosting duct 3 is provided with a pressure controller 9 for adjusting the pressure of the defrosting medium in the duct, for throttling the defrosting medium.
Referring to fig. 2, a temperature sensor 10 for detecting the temperature of the vapor-liquid mixture in the defrosting pipe 3 is provided for detecting the temperature in the pipe and comparing the current pressure to determine whether the vapor-liquid mixture exists.
Referring to fig. 1-2, the defrosting method using a vapor-liquid mixture refrigerant with medium specific enthalpy in the present embodiment includes the following steps (taking the gas refrigerant exothermic conversion mode as an example):
part of gas refrigerant (most of the gas refrigerant is used for normal refrigeration work, and the other part of the gas refrigerant is used for defrosting of an evaporator) compressed by the compressor 1 is cooled and reduced in temperature or reduced in pressure through a cooling mechanism to form a gas-liquid mixture refrigerant, wherein the enthalpy value of the gas-liquid mixture refrigerant is larger than that of the gas compressed by the compressor 1 and discharged when the gas is completely condensed, and is smaller than or equal to that of the refrigerant as a defrosting medium after refrigeration and evaporation. Inputting the vapor-liquid mixture refrigerant to an evaporator 2(a) to be defrosted through a defrosting pipeline 3, wherein the vapor-liquid mixture refrigerant is used as a defrosting medium for defrosting on the evaporator; after the defrosting operation is finished (at least one evaporator is refrigerating during the defrosting operation), the refrigerant is sent downward to the evaporator 2(b) which is refrigerating for evaporation.
Further, the temperature of the vapor-liquid mixture refrigerant is higher than the melting temperature of frost formed on the surface of the evaporator 2(a) to be defrosted and lower than the condensing temperature of the refrigeration system. Wherein, when the frosting component is ice, the melting temperature is 0 ℃.
Referring to fig. 1-2, the operation principle of the defrosting device using a vapor-liquid mixture refrigerant with medium specific enthalpy in the present embodiment is as follows:
take the way of gas refrigerant exothermic conversion as an example. When the defrosting device works, the compressor 1 compresses low-temperature and low-pressure gas refrigerant into high-temperature and high-pressure gas refrigerant by compressing work, wherein most of the refrigerant moves along the main refrigerating pipeline 4 of the refrigerating system to perform normal refrigerating work, and a small part of the refrigerant is output to the defrosting pipeline 3 and serves as defrosting medium to perform defrosting work of the evaporator.
In the defrosting pipeline 3, the gas defrosting medium is cooled down or the gas refrigerant is cooled down and depressurized through a cooling mechanism to form a vapor-liquid mixture defrosting medium with medium specific enthalpy, wherein the medium specific enthalpy mainly means that the defrosting condensation specific enthalpy of the vapor-liquid refrigerant is slightly smaller than the evaporation specific enthalpy of the defrosted refrigerant; and then the vapor-liquid mixture defrosting medium is conveyed to the evaporator 2(a) to be defrosted for melting the frosting of the evaporator. After the defrosting operation is completed, the defrosting medium (refrigerant) is downward merged with the refrigerant in the main refrigeration pipeline 4 (the throttled main pipeline 11), is conveyed to the evaporator 2(b) which is performing refrigeration for evaporation, and finally returns to the compressor 1 for circulating refrigeration.
Specifically, referring to the pressure-enthalpy diagram, the abscissa indicates the magnitude of the enthalpy, the ordinate indicates the magnitude of the pressure, the curve indicates the saturation curve, the medium in the region enclosed by the curve is in a vapor-liquid mixed state, the left side is in a liquid state, and the right side is in a gaseous state. Wherein, the 1-2 process is a process that the compressor 1 compresses gas, so that low-temperature and low-pressure gas is changed into high-temperature and high-pressure gas, the 2-3 process is an isobaric cooling process, the 3-4 process is an isenthalpic pressure reduction process, and the 4-1 process is an isobaric heat absorption process, namely representing the heat absorption capacity of the refrigeration medium.
Albeit at 2-2*The gaseous defrosting medium in this state has a large enthalpy value (including compression work), but the defrosting medium in this state has a greater capacity to release heat than to absorb heat.If 2-2*The gas under the state is used for defrosting, and because the defrosting time is difficult to control accurately, the gas still has the condition of heat release after frosting and melting often, so that the heat of compression work is transferred to the air, and the refrigeration efficiency of the refrigeration system is reduced. On the contrary, although at 3*The liquid defrosting medium in the-3 state has small enthalpy value, is easy to control, has the capacity of releasing heat equal to the capacity of absorbing heat, but has large required flow rate, low defrosting efficiency and short defrosting time interval.
Therefore, in the embodiment, the medium specific enthalpy vapor-liquid mixture is used as the defrosting medium, and by utilizing the characteristic that the heat absorption capacity is not less than the heat release capacity and the advantage of easy control, even if heat is leaked to the outside in the defrosting process, the heat can be absorbed back equally through subsequent evaporation heat absorption, and the refrigeration efficiency of the refrigeration system cannot be reduced.
Example 2
Referring to fig. 3, unlike embodiment 1, the form conversion method in this embodiment is to convert a liquid refrigerant by mixing with a gas refrigerant.
Specifically, the defrosting pipe 3 in this embodiment is provided with two access ends, one of which is connected between the condenser 5 and the oil separator 6 of the refrigeration system, and the other of which is connected behind the condenser 5 of the refrigeration system; the cooling mechanism comprises a cooler 7 arranged on the defrosting pipeline 3 and a condenser 5 of the refrigerating system, and the cooler 7 is positioned between the connection points of the two access ends. Through the structure, two access ends of the defrosting pipeline 3 respectively introduce high-temperature and high-pressure gas and condensed liquid into a main pipeline of the defrosting pipeline 3, the high-temperature and high-pressure gas is cooled by the cooler 7 and then becomes gas with a lower enthalpy value, and the gas and the condensed liquid are converged to form a gas-liquid mixture under the control of the pressure controller 9, so that the gas-liquid mixture is led to the evaporator 2(a) to be defrosted to defrost.
Example 3
Referring to fig. 4, unlike embodiment 2, the defrosting pipe 3 in this embodiment is provided with two inlets, one of which is connected between the condenser 5 and the oil separator 6 of the refrigeration system, and the other is connected behind the condenser 5 of the refrigeration system; the cooling mechanism is constituted by a condenser 5 of the refrigeration system. Through above-mentioned structure, in two incoming ends of defrosting pipeline 3 let in the trunk line of defrosting pipeline 3 with the liquid after high-temperature high-pressure gas and the condensation respectively, after high-temperature high-pressure gas and the liquid after the condensation converge, through the control of pressure controller 9, form the vapour-liquid mixture, and then lead to the evaporimeter 2(a) department of treating the defrosting with the vapour-liquid mixture, carry out the defrosting to the evaporimeter.
Further, referring to fig. 1, throttling (or pressure regulating by a pressure controller 9) the high-temperature and high-pressure gas at the point 2 to form a medium-temperature and medium-pressure gas at the point 10, throttling the liquid at the point 3 to form a vapor-liquid mixture at the point 7, mixing the medium-temperature and medium-pressure gas at the point 10 and the vapor-liquid mixture at the point 7 to form a vapor-liquid mixture at the point 6, and then introducing the mixture into the evaporator 2(a) to be defrosted to perform defrosting operation.
Or, the liquid at the point 3 is throttled (or the pressure is regulated by a pressure controller 9) to form a vapor-liquid mixture at the point 4, the vapor-liquid mixture is mixed with the high-temperature and high-pressure gas at the point 2 to form a vapor-liquid mixture at the point 6, and then the vapor-liquid mixture is introduced into the evaporator 2(a) to be defrosted to perform defrosting operation.
Specifically, when the defrosting pipe 3 is provided with two access ends, the flow of the two defrosting media (refrigerants) is adjusted by combining different enthalpy values of the two defrosting media, so that a vapor-liquid mixture is formed after the two defrosting media are converged.
Example 4
Unlike the above-described embodiments, the form conversion method in the present embodiment is the liquid refrigerant endothermic conversion. Wherein, after the condensation of condenser 5, originally for gaseous refrigerant become liquid refrigerant, liquid refrigerant evaporates the heat absorption again (carries out recondensation to the liquid refrigerant in the refrigeration trunk line, improves refrigerating capacity), turns into vapour-liquid mixture refrigerant, is used for the work of defrosting then.
In this embodiment, the form conversion mechanism is constituted by an expansion valve and a condensation evaporator which are additionally provided.
In general, the paths of the gas-liquid mixed refrigerant for obtaining the medium specific enthalpy are as follows: taking the refrigerant at the outlet of the compressor, reducing the temperature and pressure or reducing the pressure, taking the refrigerant at the outlet of the condenser, reducing the pressure or not processing the refrigerant, and mixing the two; or the refrigerant at the outlet of the compressor is subjected to temperature reduction and pressure reduction or no treatment, the refrigerant at the outlet of the condenser is subjected to pressure reduction, and the two are mixed.
The present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents and are included in the scope of the present invention.
Claims (12)
1. A defrosting method adopting a vapor-liquid mixture refrigerant with medium specific enthalpy is characterized by comprising the following steps:
converting the refrigerant in the refrigeration system into a vapor-liquid mixture refrigerant through a form conversion mechanism; and conveying the vapor-liquid mixture refrigerant to an evaporator to be defrosted, wherein the vapor-liquid mixture refrigerant is used as a defrosting medium to release heat to melt frosting on the evaporator.
2. The defrosting method adopting a gas-liquid mixture refrigerant with intermediate specific enthalpy according to claim 1, characterized in that the transformation modes of the form transformation mechanism comprise gas refrigerant heat-releasing transformation, liquid refrigerant heat-absorbing transformation and liquid refrigerant and gas refrigerant mixing transformation.
3. The defrosting method adopting a gas-liquid mixture refrigerant with intermediate specific enthalpy according to claim 2, characterized in that the gas refrigerant exothermal conversion mode is: the gas refrigerant compressed by the compressor is cooled or depressurized through the cooling mechanism to form a gas-liquid mixture refrigerant.
4. The defrosting method using a vapor-liquid mixture refrigerant with intermediate specific enthalpy according to claim 1, wherein in defrosting operation, at least one evaporator is refrigerating; after the defrosting operation is finished, the refrigerant is conveyed downwards to an evaporator which is performing the refrigeration operation for evaporation, or conveyed to a liquid storage container for storage.
5. The defrosting method using a vapor-liquid mixture refrigerant with intermediate specific enthalpy according to claim 1, wherein the enthalpy of the vapor-liquid mixture refrigerant is greater than the enthalpy when the gas compressed by the compressor and discharged is completely condensed, and is less than or equal to the enthalpy of the refrigerant as a defrosting medium after being evaporated for cooling.
6. The defrosting method using a vapor-liquid mixture refrigerant with intermediate specific enthalpy according to claim 5, characterized in that the temperature of the vapor-liquid mixture refrigerant is higher than the melting temperature of the frost on the surface of the evaporator to be defrosted and lower than the condensing temperature of the refrigeration system.
7. An apparatus for applying the defrosting method using a vapor-liquid mixture refrigerant with medium specific enthalpy according to any one of claims 1 to 6, which is integrated in a refrigeration system, and which comprises a form converting mechanism for converting the refrigerant in the refrigeration system into the vapor-liquid mixture refrigerant and a defrosting pipe for delivering the vapor-liquid mixture to an evaporator to be defrosted, wherein the defrosting pipe is bypassed to a main refrigeration pipe of the refrigeration system.
8. The defrosting device using a vapor-liquid mixture refrigerant with intermediate specific enthalpy according to claim 7, wherein the form transforming mechanism includes a cooling mechanism for reducing enthalpy of the gas compressed by the compressor to form a vapor-liquid mixture.
9. The defrosting device using a vapor-liquid mixture refrigerant with intermediate specific enthalpy according to claim 8, wherein the defrosting pipe has a head end which is an inlet end connected between a condenser and an oil separator of a refrigeration system and a tail end which extends to an evaporator to be defrosted;
the cooling mechanism comprises a cooler arranged on the defrosting pipeline.
10. The defrosting device using a vapor-liquid mixture refrigerant with intermediate specific enthalpy according to claim 8, wherein the defrosting pipe is provided with two inlets, one of which is connected between the condenser and the oil separator of the refrigeration system, and the other is connected behind the condenser of the refrigeration system;
the cooling mechanism comprises a cooler arranged on the defrosting pipeline and a condenser of the refrigerating system, and the cooler is positioned between connecting points of the two access ends.
11. The defrosting device using a vapor-liquid mixture refrigerant with intermediate specific enthalpy according to claim 8, wherein the defrosting pipe is provided with two inlets, one of which is connected between the condenser and the oil separator of the refrigeration system, and the other is connected behind the condenser of the refrigeration system;
the cooling mechanism is composed of a condenser of a refrigeration system.
12. The defrosting device adopting a gas-liquid mixture refrigerant with intermediate specific enthalpy according to any one of claims 9 to 11, wherein the access end of the defrosting pipe is provided with a flow control valve for controlling the flow of the refrigerant introduced into the pipe;
and the defrosting pipeline is provided with a pressure controller for adjusting the pressure of the defrosting medium in the pipeline and a temperature sensor for detecting the temperature of the defrosting medium in the pipeline.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010458376.2A CN111536721A (en) | 2020-05-26 | 2020-05-26 | Defrosting method and device adopting medium specific enthalpy vapor-liquid mixture refrigerant |
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| US20130019617A1 (en) * | 2011-07-20 | 2013-01-24 | Thermo King Corporation | Defrost for transcritical vapor compression system |
| CN204648783U (en) * | 2015-05-11 | 2015-09-16 | 浙江商业职业技术学院 | With the hot fluorine defrosting device of heat exchange gas-liquid separator |
| CN204786911U (en) * | 2015-06-11 | 2015-11-18 | 泰豪科技股份有限公司 | Novel defrosting low temperature dehumidifier |
| CN206739692U (en) * | 2016-11-01 | 2017-12-12 | 安徽美乐柯制冷空调设备有限公司 | A kind of defrosting and refrigeration system and freezer |
| CN109269140A (en) * | 2018-10-30 | 2019-01-25 | 天津商业大学 | It is a kind of can continuous heat supply defrosting net for air-source heat pump units |
| CN110762872A (en) * | 2019-11-14 | 2020-02-07 | 天津商业大学 | Air cooler system capable of alternately defrosting |
| CN212274331U (en) * | 2020-05-26 | 2021-01-01 | 广东省现代农业装备研究所 | Defrosting device adopting medium specific enthalpy vapor-liquid mixture refrigerant |
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| US20130019617A1 (en) * | 2011-07-20 | 2013-01-24 | Thermo King Corporation | Defrost for transcritical vapor compression system |
| CN204648783U (en) * | 2015-05-11 | 2015-09-16 | 浙江商业职业技术学院 | With the hot fluorine defrosting device of heat exchange gas-liquid separator |
| CN204786911U (en) * | 2015-06-11 | 2015-11-18 | 泰豪科技股份有限公司 | Novel defrosting low temperature dehumidifier |
| CN206739692U (en) * | 2016-11-01 | 2017-12-12 | 安徽美乐柯制冷空调设备有限公司 | A kind of defrosting and refrigeration system and freezer |
| CN109269140A (en) * | 2018-10-30 | 2019-01-25 | 天津商业大学 | It is a kind of can continuous heat supply defrosting net for air-source heat pump units |
| CN110762872A (en) * | 2019-11-14 | 2020-02-07 | 天津商业大学 | Air cooler system capable of alternately defrosting |
| CN212274331U (en) * | 2020-05-26 | 2021-01-01 | 广东省现代农业装备研究所 | Defrosting device adopting medium specific enthalpy vapor-liquid mixture refrigerant |
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