US20030167793A1 - Vapor-compression type refrigerating machine and heat exchanger therefor - Google Patents
Vapor-compression type refrigerating machine and heat exchanger therefor Download PDFInfo
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- US20030167793A1 US20030167793A1 US10/373,217 US37321703A US2003167793A1 US 20030167793 A1 US20030167793 A1 US 20030167793A1 US 37321703 A US37321703 A US 37321703A US 2003167793 A1 US2003167793 A1 US 2003167793A1
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- Prior art keywords
- refrigerant
- evaporator
- refrigerating machine
- heat exchanger
- compressor
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
- F28F13/18—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
- F28F13/185—Heat-exchange surfaces provided with microstructures or with porous coatings
- F28F13/187—Heat-exchange surfaces provided with microstructures or with porous coatings especially adapted for evaporator surfaces or condenser surfaces, e.g. with nucleation sites
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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
- F25B39/00—Evaporators; Condensers
- F25B39/02—Evaporators
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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
- F25B41/00—Fluid-circulation arrangements
-
- 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
- F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
- F25B43/02—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat for separating lubricants from the refrigerant
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
- F28F13/18—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing
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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
- F25B2341/00—Details of ejectors not being used as compression device; Details of flow restrictors or expansion valves
- F25B2341/001—Ejectors not being used as compression device
- F25B2341/0012—Ejectors with the cooled primary flow at high pressure
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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
- F25B2500/00—Problems to be solved
- F25B2500/18—Optimization, e.g. high integration of refrigeration components
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
- F28F2245/00—Coatings; Surface treatments
- F28F2245/04—Coatings; Surface treatments hydrophobic
Definitions
- the present invention relates to an evaporator used for a vapor-compression type refrigerating machine in which heat is moved from the low temperature side to the high temperature side.
- the present invention is effectively applied to a vapor-compression type refrigerating machine having an ejector by which suction pressure of a compressor is increased when expansion energy of refrigerant is converted into pressure energy while the refrigerant is expanded while being decompressed.
- Refrigerating machine oil staying in the heat exchanger adheres to the inner walls of the tubes of the heat exchanger, and a substantial sectional area of the refrigerant path is reduced, so that a pressure loss (refrigerant circulating resistance) is increased in the heat exchanger, and the coefficient of heat transfer between the refrigerant and the tubes is decreased. As a result, the heat exchanging capacity of the heat exchanger is lowered.
- a heat exchanger applied to a vapor-compression type refrigerating machine, an oil repellent film ( 31 a ) having an oil repelling property being formed on an inner wall face of a tube ( 31 ) composing a refrigerant path.
- a heat exchanger applied to an evaporator which is one of the heat exchangers provided in a vapor-compression type refrigerating machine and which exhibits a refrigerating capacity by evaporating refrigerant, an oil repellent film ( 31 a ) having an oil repelling property being formed on an inner wall face of a tube ( 31 ) composing a refrigerant path.
- surface tension of material composing the oil repellent film ( 31 a ) is lower than that of refrigerating machine oil mixed with refrigerant.
- material composing the repellent oil film ( 31 a ) is silicon resin or fluororesin.
- a vapor-compression type refrigerating machine comprising; a compressor ( 10 ) for sucking and compressing refrigerant; a radiator ( 20 ) for cooling refrigerant discharged from the compressor ( 10 ); an evaporator ( 30 ) for evaporating refrigerant so as to absorb heat, composed of a heat exchanger as described before; a nozzle ( 41 ) for converting the pressure energy of a refrigerant at high pressure, which has flowed out from the radiator ( 20 ), into velocity energy by expanding refrigerant in a reduced pressure; an ejector ( 40 ) including a boosting section ( 42 , 43 ) for boosting the pressure of refrigerant by converting velocity energy into pressure energy when refrigerant of a gas phase, evaporated in the evaporator ( 30 ), is sucked by a flow of refrigerant of high velocity injected from the nozzle ( 41 ) and then the refrig
- FIG. 1 is a view showing a model of an ejector cycle relating to an embodiment of the present invention
- FIG. 2A is a perspective view of an evaporator applied to the ejector cycle relating to the embodiment of the present invention
- FIG. 2B is a sectional view of a tube
- FIG. 3 is a view showing a model of the ejector relating to the embodiment of the present invention.
- FIG. 4 is a p-h diagram.
- FIG. 1 is a view showing a model of the ejector cycle.
- the compressor 10 is a well known variable displacement type compressor in which refrigerant is sucked and compressed when power is supplied to the compressor from an engine.
- the radiator 20 is a heat exchanger on the high pressure side for exchanging heat between refrigerant, which has been discharged from the compressor 10 , and outside air so as to cool refrigerant.
- the pressure of the refrigerant in the radiator 20 is not higher than the critical pressure of the refrigerant. Therefore, the refrigerant is condensed in the radiator 20 .
- the evaporator 30 is a heat exchanger on the low pressure side in which heat is exchanged between the air blowing out into a room and the liquid phase refrigerant so that the liquid phase refrigerant can be evaporated and the air blowing out into the room can be cooled.
- the evaporator 30 is composed in such a manner that a plurality of tubes 31 composing the refrigerant paths are serpentined and the thin sheet-shaped fins 32 , to increase the heat transfer area with respect to air, are joined to the outer faces of the tubes 31 .
- the oil repellent film 31 a having an oil repelling property is formed on the inner wall face of each tube 31 .
- This oil repellent films 31 a is made of a material, the surface tension of which is lower than that of refrigerating machine oil.
- the oil repellent film 31 a is made of silicon resin or fluororesin.
- Silicon resin has groups of CH 3
- fluororesin has groups of CF 3 or CF 2 .
- the tube 31 is made of phosphorus deoxidized copper alloy, and the oil repellent film 31 a is made of silicon resin, and the thickness of the film is kept at 0.1 to 3 ⁇ m.
- the oil repellent film 31 a is formed on the tube 31 when the tube 31 is soaked in a solution in which material of the oil repellent film 31 a is dissolved.
- the ejector 40 expands refrigerant under the condition that the pressure is reduced, so that the ejector 40 sucks gas-phase refrigerant which has evaporated in the evaporator 30 . Further, the ejector 40 converts expansion energy into pressure energy so that the suction pressure of the compressor 10 can be increased.
- the ejector 40 includes: a nozzle 41 which converts pressure energy of high pressure refrigerant, which flows into the ejector 40 , into velocity energy so that refrigerant can be isoentropically expanded under the condition that pressure is reduced; a mixing section 42 for sucking gas-phase refrigerant, which has evaporated in the evaporator 30 , by a flow of refrigerant of high velocity injected by the nozzle 41 and mixing it with a flow of refrigerant injected from the nozzle 41 ; and a diffuser 43 for boosting the pressure of refrigerant by converting velocity energy into pressure energy while refrigerant injected from the nozzle 41 is mixed with refrigerant sucked from the evaporator 30 .
- a Laval nozzle which has a throat section, the path area of which is the smallest, in the middle of the path.
- the mixing section 42 mixing is conducted so that a sum of the momentum of a flow of refrigerant injected from the nozzle 41 and the momentum of a flow of refrigerant sucked from the evaporator 30 to the ejector 40 can be preserved. Therefore, static pressure is increased even in the mixing section 42 .
- the diffuser 43 when the sectional area of the path is gradually increased, a dynamic pressure of refrigerant is converted into a static pressure. Therefore, in the ejector 40 , the pressure of refrigerant is increased in both the mixing section 42 and the diffuser 43 . Therefore, the mixing section 42 and the diffuser 43 are generically called a boosting section.
- the gas-liquid separator 50 is a gas-liquid separating means into which refrigerant flows after it has flowed out from the ejector 40 , and the refrigerant, which has flowed into the gas-liquid separator 50 , is separated to gas-phase refrigerant and liquid-phase refrigerant, and the thus separated liquid-phase refrigerant is stored.
- An outlet for gas-phase refrigerant of the gas-liquid separator 50 is connected with the suction side of the compressor 10
- an outlet for liquid-phase refrigerant of the gas-liquid separator 50 is connected with the entry side of the evaporator 30 .
- FIG. 4 is a diagram showing a relation between p (absolute pressure of refrigerant) and h (specific enthalpy).
- p absolute pressure of refrigerant
- h specific enthalpy
- mark ⁇ shown in FIG. 4 represents a state of refrigerant at a position indicated by mark ⁇ in FIG. 1.
- the driving flow is made to circulate by the compressor 10 .
- the sucking flow 10 is made to circulate by a boosting action generated by the ejector 40 , that is, the sucking flow 10 is made to circulate by a pump action generated by a difference in pressure between the outlet of refrigerant of the ejector 40 and the inlet of liquid phase refrigerant of the ejector 40 . Accordingly, when a flow rate of the driving flow is decreased and a boosting action generated by the ejector 40 is reduced, a flow rate of refrigerant of the sucking flow is decreased. Therefore, refrigerating machine oil, which has flowed into the evaporator 30 together with liquid phase refrigerant, tends to stay in the evaporator 30 .
- the present invention is applied to an evaporator provided in the ejector cycle.
- the present invention is not limited to the above specific embodiment. It is possible to apply the present invention to an evaporator provided in the expansion valve cycle.
- the present invention can be applied to any type evaporator 30 , that is, the present invention can be applied to a serpentine type heat exchanger in which the tube 31 is snaked. Also, the present invention can be applied to a multi-flow type heat exchanger composed of a plurality of tubes, header tanks and others.
- the vapor-compression type refrigerating machine in which the ejector of the present invention is used, is applied to an air-conditioner for vehicle use.
- the present invention is not limited to the above specific application.
- the present invention is applied to an evaporator.
- the present invention is not limited to the above specific embodiment. It is possible to apply the present invention to a heat exchanger on the high pressure side such as a radiator 20 .
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Power Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Applications Or Details Of Rotary Compressors (AREA)
- Paints Or Removers (AREA)
- Compressor (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
An oil repellent film 31 a is formed on an inner wall of the tube 31. By the formation of the oil repellent film 31 a, it becomes possible to prevent refrigerating machine oil remaining in the evaporator 30. Therefore, a sufficiently large quantity of refrigerating machine oil can be returned to the compressor, and the occurrence of seizing of the compressor can be prevented. As it is possible to prevent refrigerating machine oil remaining in the evaporator 30, while a reduction in the coefficient of heat transfer between refrigerant and the tube is being prevented, it is possible to prevent a substantial sectional area of the refrigerant path of the tube 31 from decreasing. Therefore, an increase in the pressure loss in the evaporator 30 can be prevented. Accordingly, the heat absorbing property of the evaporator 30 can be enhanced.
Description
- 1. Field of the Invention
- The present invention relates to an evaporator used for a vapor-compression type refrigerating machine in which heat is moved from the low temperature side to the high temperature side. The present invention is effectively applied to a vapor-compression type refrigerating machine having an ejector by which suction pressure of a compressor is increased when expansion energy of refrigerant is converted into pressure energy while the refrigerant is expanded while being decompressed.
- 2. Description of the Related Art
- Usually, in the vapor-compression type refrigerating machine, sliding sections provided in the compressor are lubricated when refrigerant mixed with refrigerating machine oil is circulated in the refrigerating machine.
- Therefore, refrigerating machine oil flows into a heat exchanger, such as an evaporator, together with the refrigerant. When refrigerating machine oil flowing into the heat exchanger stays in the heat exchanger, the following problems may be encountered.
- (1) As a quantity of refrigerating machine oil returning to the compressor is reduced, lubrication of the compressor becomes incomplete, which causes seizing of the compressor.
- (2) Refrigerating machine oil staying in the heat exchanger adheres to the inner walls of the tubes of the heat exchanger, and a substantial sectional area of the refrigerant path is reduced, so that a pressure loss (refrigerant circulating resistance) is increased in the heat exchanger, and the coefficient of heat transfer between the refrigerant and the tubes is decreased. As a result, the heat exchanging capacity of the heat exchanger is lowered.
- In view of the above problems, the present invention has been accomplished. It is an object of the present invention to solve the above problems described in the above items (1) and (2).
- In order to accomplish the above object, according to an aspect of the present invention, there is provided a heat exchanger applied to a vapor-compression type refrigerating machine, an oil repellent film (31 a) having an oil repelling property being formed on an inner wall face of a tube (31) composing a refrigerant path.
- Due to the foregoing, it is possible to prevent refrigerating machine oil from staying in the heat exchanger (30). Therefore, a sufficiently large quantity of refrigerant machine oil can be returned to the compressor. Accordingly, the occurrence of trouble such as seizing of the compressor can be prevented.
- As it is possible to prevent refrigerating machine oil from staying in the heat exchanger (30), while the coefficient of heat transfer between refrigerant and the tube (31) is prevented from deteriorating, a substantial reduction of the sectional area of the refrigerant path of the tube (31) can be prevented. Therefore, an increase in the pressure loss in the heat exchanger (30) can be prevented, and the heat exchanging capacity of the heat exchanger (30) can be enhanced.
- According to another aspect of the present invention, there is provided a heat exchanger applied to an evaporator, which is one of the heat exchangers provided in a vapor-compression type refrigerating machine and which exhibits a refrigerating capacity by evaporating refrigerant, an oil repellent film (31 a) having an oil repelling property being formed on an inner wall face of a tube (31) composing a refrigerant path.
- Due to the foregoing, it is possible to prevent refrigerating machine oil from staying in the heat exchanger (30). Therefore, a sufficiently large quantity of refrigerant machine oil can be returned to the compressor. Accordingly, the occurrence of trouble such as seizing of the compressor can be previously prevented.
- As it is possible to prevent refrigerating machine oil from staying in the heat exchanger (30), while the coefficient of heat transfer between refrigerant and the tube (31) is prevented from deteriorating, a substantial reduction of the sectional area of the refrigerant path of the tube (31) can be prevented. Therefore, an increase in the pressure loss in the heat exchanger (30) can be prevented, and the heat exchanging capacity of the heat exchanger (30) can be enhanced.
- In this connection, it is preferable that surface tension of material composing the oil repellent film (31 a) is lower than that of refrigerating machine oil mixed with refrigerant.
- It is preferable that material composing the repellent oil film (31 a) is silicon resin or fluororesin.
- According to still another aspect of the present invention, there is provided a vapor-compression type refrigerating machine comprising; a compressor (10) for sucking and compressing refrigerant; a radiator (20) for cooling refrigerant discharged from the compressor (10); an evaporator (30) for evaporating refrigerant so as to absorb heat, composed of a heat exchanger as described before; a nozzle (41) for converting the pressure energy of a refrigerant at high pressure, which has flowed out from the radiator (20), into velocity energy by expanding refrigerant in a reduced pressure; an ejector (40) including a boosting section (42, 43) for boosting the pressure of refrigerant by converting velocity energy into pressure energy when refrigerant of a gas phase, evaporated in the evaporator (30), is sucked by a flow of refrigerant of high velocity injected from the nozzle (41) and then the refrigerant injected by the nozzle (41) and the refrigerant sucked from the evaporator (30) are mixed with each other so as to convert velocity energy into pressure energy; and a gas-liquid separator (50) for separating refrigerant into gas-phase refrigerant and liquid-phase refrigerant and supplying the liquid-phase refrigerant to the evaporator (30) and also supplying gas-phase refrigerant to the compressor (10).
- Due to the foregoing, it is possible to enhance the operating efficiency of the vapor-compression type refrigerating machine.
- In this connection, numbers written in the parentheses after each means represent an example of a corresponding relation of the specific means in the embodiment described later.
- The present invention may be more fully understood from the description of preferred embodiments of the invention, as set forth below, together with the accompanying drawings.
- In the drawings:
- FIG. 1 is a view showing a model of an ejector cycle relating to an embodiment of the present invention;
- FIG. 2A is a perspective view of an evaporator applied to the ejector cycle relating to the embodiment of the present invention;
- FIG. 2B is a sectional view of a tube;
- FIG. 3 is a view showing a model of the ejector relating to the embodiment of the present invention; and
- FIG. 4 is a p-h diagram.
- In this embodiment, an ejector cycle of the present invention is applied to an air-conditioner for vehicle use. FIG. 1 is a view showing a model of the ejector cycle.
- In FIG. 1, the
compressor 10 is a well known variable displacement type compressor in which refrigerant is sucked and compressed when power is supplied to the compressor from an engine. Theradiator 20 is a heat exchanger on the high pressure side for exchanging heat between refrigerant, which has been discharged from thecompressor 10, and outside air so as to cool refrigerant. - In this connection, as chlorofluorocarbon is used as refrigerant in this embodiment, the pressure of the refrigerant in the
radiator 20 is not higher than the critical pressure of the refrigerant. Therefore, the refrigerant is condensed in theradiator 20. - The
evaporator 30 is a heat exchanger on the low pressure side in which heat is exchanged between the air blowing out into a room and the liquid phase refrigerant so that the liquid phase refrigerant can be evaporated and the air blowing out into the room can be cooled. - In this connection, as shown in FIG. 2A, the
evaporator 30 is composed in such a manner that a plurality oftubes 31 composing the refrigerant paths are serpentined and the thin sheet-shaped fins 32, to increase the heat transfer area with respect to air, are joined to the outer faces of thetubes 31. - As shown in FIG. 2B, on the inner wall face of each
tube 31, theoil repellent film 31a having an oil repelling property is formed. This oil repellent films 31 a is made of a material, the surface tension of which is lower than that of refrigerating machine oil. In this embodiment, theoil repellent film 31 a is made of silicon resin or fluororesin. - In this connection, refrigerating machine oil lubricates sliding sections and other sections provided in the
compressor 10. Silicon resin has groups of CH3, and fluororesin has groups of CF3 or CF2. - In this embodiment, the
tube 31 is made of phosphorus deoxidized copper alloy, and theoil repellent film 31 a is made of silicon resin, and the thickness of the film is kept at 0.1 to 3 μm. Theoil repellent film 31 a is formed on thetube 31 when thetube 31 is soaked in a solution in which material of theoil repellent film 31 a is dissolved. - In FIG. 1, the
ejector 40 expands refrigerant under the condition that the pressure is reduced, so that theejector 40 sucks gas-phase refrigerant which has evaporated in theevaporator 30. Further, theejector 40 converts expansion energy into pressure energy so that the suction pressure of thecompressor 10 can be increased. - In this connection, as shown in FIG. 3, the
ejector 40 includes: anozzle 41 which converts pressure energy of high pressure refrigerant, which flows into theejector 40, into velocity energy so that refrigerant can be isoentropically expanded under the condition that pressure is reduced; amixing section 42 for sucking gas-phase refrigerant, which has evaporated in theevaporator 30, by a flow of refrigerant of high velocity injected by thenozzle 41 and mixing it with a flow of refrigerant injected from thenozzle 41; and adiffuser 43 for boosting the pressure of refrigerant by converting velocity energy into pressure energy while refrigerant injected from thenozzle 41 is mixed with refrigerant sucked from theevaporator 30. - In this embodiment, in order to increase the velocity of refrigerant jetting out from the
nozzle 41 to a value not lower than the sound velocity, a Laval nozzle is adopted which has a throat section, the path area of which is the smallest, in the middle of the path. - In the
mixing section 42, mixing is conducted so that a sum of the momentum of a flow of refrigerant injected from thenozzle 41 and the momentum of a flow of refrigerant sucked from theevaporator 30 to theejector 40 can be preserved. Therefore, static pressure is increased even in themixing section 42. On the other hand, in thediffuser 43, when the sectional area of the path is gradually increased, a dynamic pressure of refrigerant is converted into a static pressure. Therefore, in theejector 40, the pressure of refrigerant is increased in both themixing section 42 and thediffuser 43. Therefore, the mixingsection 42 and thediffuser 43 are generically called a boosting section. - In FIG. 1, the gas-
liquid separator 50 is a gas-liquid separating means into which refrigerant flows after it has flowed out from theejector 40, and the refrigerant, which has flowed into the gas-liquid separator 50, is separated to gas-phase refrigerant and liquid-phase refrigerant, and the thus separated liquid-phase refrigerant is stored. An outlet for gas-phase refrigerant of the gas-liquid separator 50 is connected with the suction side of thecompressor 10, and an outlet for liquid-phase refrigerant of the gas-liquid separator 50 is connected with the entry side of theevaporator 30. - In this connection, FIG. 4 is a diagram showing a relation between p (absolute pressure of refrigerant) and h (specific enthalpy). In this diagram, the overall macro operation of the ejector cycle is shown. This macro operation of the ejector cycle is the same as that of the well-known ejector cycle. Therefore, in this embodiment, an explanation of the overall macro operation of the ejector cycle are omitted. In this connection, mark shown in FIG. 4 represents a state of refrigerant at a position indicated by mark in FIG. 1.
- Next, characteristics of this embodiment will be described as follows.
- In this embodiment, as the
oil repellent film 31 a is formed on the inner wall of eachtube 31, it is possible to prevent refrigerating machine oil from staying in theevaporator 30. Therefore, a sufficiently large quantity of refrigerant machine oil can be returned to thecompressor 10. Accordingly, the occurrence of trouble such as seizing of thecompressor 10 can be prevented. - As it is possible to prevent refrigerating machine oil from staying in the
evaporator 30, while the coefficient of heat transfer between refrigerant and the tube (31) is prevented from deteriorating, a reduction of the substantial sectional area of the refrigerant path can be prevented. Therefore, an increase in the pressure loss in theevaporator 30 can be prevented, and the heat absorbing capacity of theevaporator 30 can be enhanced. - In the vapor-compression type refrigerating machine in which the pressure of refrigerant is isoentropically reduced by a pressure reducing means such as an expansion valve (This cycle will be referred to as an expansion valve cycle, hereinafter.), refrigerant which has flowed out from the expansion valve flows into the evaporator. On the other hand, in the ejector cycle, as shown in FIG. 1, refrigerant which has flowed out from the
ejector 40 flows into the gas-liquid separator 50, and liquid phase refrigerant separated by the gas-liquid separator 50 is supplied to theevaporator 30, and gas phase refrigerant separated by the gas-liquid separator 50 is sucked into thecompressor 10. - In other words, in the expansion valve cycle, there is one refrigerant flow in which refrigerant circulates in the order of compressor→radiator→expansion valve→evaporator→compressor. On the other hand, in the ejector cycle, there are two refrigerant flows. In one flow, refrigerant flows in the order of
compressor 10→radiator 20→ejector 40→gas-liquid separator 50→compressor 10 (This flow will be referred to as a driving flow, hereinafter.). In the other flow, refrigerant flows in the order of gas-liquid separator 50→evaporator 30→ejector 40→gas-liquid separator 50 (This flow will be referred to as a sucking flow, hereinafter.). - In this case, the driving flow is made to circulate by the
compressor 10. On the other hand, the suckingflow 10 is made to circulate by a boosting action generated by theejector 40, that is, the suckingflow 10 is made to circulate by a pump action generated by a difference in pressure between the outlet of refrigerant of theejector 40 and the inlet of liquid phase refrigerant of theejector 40. Accordingly, when a flow rate of the driving flow is decreased and a boosting action generated by theejector 40 is reduced, a flow rate of refrigerant of the sucking flow is decreased. Therefore, refrigerating machine oil, which has flowed into theevaporator 30 together with liquid phase refrigerant, tends to stay in theevaporator 30. - On the other hand, in the expansion cycle, refrigerant is directly sucked from the evaporator by the compressor. Therefore, even when a heat load is decreased, it is difficult for refrigerating machine oil to stay in the evaporator compared with the ejector cycle. Accordingly, it is especially effective for the present invention to be applied to the
evaporator 30 provided in the ejector cycle. - In the above embodiment, the present invention is applied to an evaporator provided in the ejector cycle. However, it should be noted that the present invention is not limited to the above specific embodiment. It is possible to apply the present invention to an evaporator provided in the expansion valve cycle.
- It is possible to apply the present invention to any
type evaporator 30, that is, the present invention can be applied to a serpentine type heat exchanger in which thetube 31 is snaked. Also, the present invention can be applied to a multi-flow type heat exchanger composed of a plurality of tubes, header tanks and others. - In the above embodiment, the vapor-compression type refrigerating machine, in which the ejector of the present invention is used, is applied to an air-conditioner for vehicle use. However, the present invention is not limited to the above specific application.
- In the above embodiment, the present invention is applied to an evaporator. However, it should be noted that the present invention is not limited to the above specific embodiment. It is possible to apply the present invention to a heat exchanger on the high pressure side such as a
radiator 20.
Claims (5)
1. A heat exchanger applied to a vapor-compression type refrigerating machine, an oil repellent film having an oil repelling property being formed on an inner wall face of a tube composing a refrigerant path.
2. A heat exchanger applied to an evaporator, which is one of the heat exchangers provided in a vapor-compression type refrigerating machine and exhibits a refrigerating capacity by evaporating refrigerant, an oil repellent film having an oil repelling property being formed on an inner wall face of a tube composing a refrigerant path.
3. A heat exchanger according to claim 1 , wherein surface tension of material composing the oil repellent film is lower than that of refrigerating machine oil mixed with refrigerant.
4. A heat exchanger according to claim 1 , wherein material composing the oil repellent film is silicon resin or fluororesin.
5. A vapor-compression type refrigerating machine using an ejector, comprising;
a compressor for sucking and compressing refrigerant;
a radiator for cooling refrigerant discharged from the compressor;
an evaporator for evaporating refrigerant so as to absorb heat, composed of a heat exchanger described in claim 1;
a nozzle for converting pressure energy of refrigerant of high pressure, which has flowed out from the radiator, into velocity energy by expanding refrigerant in a reduced pressure;
an ejector including a boosting section for boosting the pressure of refrigerant by converting velocity energy into pressure energy when refrigerant of gas phase evaporated in the evaporator is sucked by a flow of refrigerant of high velocity injected from the nozzle and then refrigerant injected by the nozzle and refrigerant sucked from the evaporator are mixed with each other so as to convert velocity energy into pressure energy; and
a gas-liquid separator for separating refrigerant into gas-phase refrigerant and liquid-phase refrigerant and supplying the liquid-phase refrigerant to the evaporator and also supplying gas-phase refrigerant to the compressor.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2002063425A JP2003262432A (en) | 2002-03-08 | 2002-03-08 | Heat exchanger for vapor compression refrigerator |
JP2002-063425 | 2002-03-08 |
Publications (1)
Publication Number | Publication Date |
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US20030167793A1 true US20030167793A1 (en) | 2003-09-11 |
Family
ID=27784925
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/373,217 Abandoned US20030167793A1 (en) | 2002-03-08 | 2003-02-24 | Vapor-compression type refrigerating machine and heat exchanger therefor |
Country Status (4)
Country | Link |
---|---|
US (1) | US20030167793A1 (en) |
JP (1) | JP2003262432A (en) |
CN (1) | CN1443999A (en) |
DE (1) | DE10309840A1 (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20070119207A1 (en) * | 2004-09-22 | 2007-05-31 | Denso Corporation | Ejector-type refrigerant cycle device |
WO2008061726A2 (en) * | 2006-11-21 | 2008-05-29 | Eugster/Frismag Ag | Heat exchanger for cooling or heating a fluid, coolant circuit and method for cooling or heating a working fluid or a heat exchanger |
EP2077429A1 (en) * | 2006-10-18 | 2009-07-08 | Daikin Industries, Ltd. | Heat exchanger and refrigeration device |
CN101832680A (en) * | 2010-04-27 | 2010-09-15 | 大连理工大学 | Two-stage steam jet refrigeration system |
US20180098438A1 (en) * | 2016-07-22 | 2018-04-05 | International Business Machines Corporation | Implementing backdrilling elimination utilizing anti-electroplate coating |
US11435116B2 (en) | 2017-09-25 | 2022-09-06 | Johnson Controls Tyco IP Holdings LLP | Two step oil motive eductor system |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100436962C (en) * | 2005-08-04 | 2008-11-26 | 株式会社电装 | Refrigeration cycle device with injector |
JP5999050B2 (en) * | 2013-08-29 | 2016-09-28 | 株式会社デンソー | Ejector refrigeration cycle and ejector |
JP5999081B2 (en) * | 2013-12-24 | 2016-09-28 | 株式会社豊田中央研究所 | Cooled element and selective deposition method |
CN105508256B (en) * | 2016-01-19 | 2019-07-05 | 广东美芝制冷设备有限公司 | Rotary compressor and heat-exchange system with it |
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-
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- 2002-03-08 JP JP2002063425A patent/JP2003262432A/en active Pending
-
2003
- 2003-02-24 US US10/373,217 patent/US20030167793A1/en not_active Abandoned
- 2003-03-06 DE DE10309840A patent/DE10309840A1/en not_active Withdrawn
- 2003-03-10 CN CN03119948A patent/CN1443999A/en active Pending
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US3464230A (en) * | 1966-07-01 | 1969-09-02 | Philips Corp | Systems for producing cold and ejectors in such systems |
US3496735A (en) * | 1967-07-27 | 1970-02-24 | Philips Corp | Ejector in refrigerating device |
US4187695A (en) * | 1978-11-07 | 1980-02-12 | Virginia Chemicals Inc. | Air-conditioning system having recirculating and flow-control means |
US4427034A (en) * | 1980-05-23 | 1984-01-24 | Sumitomo Light Metal Industries, Ltd. | Coating composition for protecting inner surface of tubes in heat exchangers |
US5184478A (en) * | 1990-08-27 | 1993-02-09 | Nippondenso Co., Ltd. | Refrigerant apparatus |
US5343711A (en) * | 1993-01-04 | 1994-09-06 | Virginia Tech Intellectual Properties, Inc. | Method of reducing flow metastability in an ejector nozzle |
US6164078A (en) * | 1999-03-04 | 2000-12-26 | Boeing North American Inc. | Cryogenic liquid heat exchanger system with fluid ejector |
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Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
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US20070119207A1 (en) * | 2004-09-22 | 2007-05-31 | Denso Corporation | Ejector-type refrigerant cycle device |
US7757514B2 (en) * | 2004-09-22 | 2010-07-20 | Denso Corporation | Ejector-type refrigerant cycle device |
US20100257893A1 (en) * | 2004-09-22 | 2010-10-14 | Denso Corporation | Ejector-type refrigerant cycle device |
US8186180B2 (en) | 2004-09-22 | 2012-05-29 | Denso Corporation | Ejector-type refrigerant cycle device |
EP2077429A1 (en) * | 2006-10-18 | 2009-07-08 | Daikin Industries, Ltd. | Heat exchanger and refrigeration device |
EP2077429A4 (en) * | 2006-10-18 | 2014-05-07 | Daikin Ind Ltd | Heat exchanger and refrigeration device |
WO2008061726A2 (en) * | 2006-11-21 | 2008-05-29 | Eugster/Frismag Ag | Heat exchanger for cooling or heating a fluid, coolant circuit and method for cooling or heating a working fluid or a heat exchanger |
WO2008061726A3 (en) * | 2006-11-21 | 2009-01-15 | Eugster Frismag Ag | Heat exchanger for cooling or heating a fluid, coolant circuit and method for cooling or heating a working fluid or a heat exchanger |
CN101832680A (en) * | 2010-04-27 | 2010-09-15 | 大连理工大学 | Two-stage steam jet refrigeration system |
US20180098438A1 (en) * | 2016-07-22 | 2018-04-05 | International Business Machines Corporation | Implementing backdrilling elimination utilizing anti-electroplate coating |
US10798829B2 (en) * | 2016-07-22 | 2020-10-06 | International Business Machines Corporation | Implementing backdrilling elimination utilizing anti-electroplate coating |
US11435116B2 (en) | 2017-09-25 | 2022-09-06 | Johnson Controls Tyco IP Holdings LLP | Two step oil motive eductor system |
Also Published As
Publication number | Publication date |
---|---|
DE10309840A1 (en) | 2003-09-25 |
CN1443999A (en) | 2003-09-24 |
JP2003262432A (en) | 2003-09-19 |
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Legal Events
Date | Code | Title | Description |
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AS | Assignment |
Owner name: DENSO CORPORATION, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HONDA, TOMOO;TAKEUCHI, HIROTSUGU;REEL/FRAME:013818/0676 Effective date: 20030114 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |