US3884663A - Refrigerator system with refrigerant expansion through capillary tubes of adjustable length - Google Patents

Refrigerator system with refrigerant expansion through capillary tubes of adjustable length Download PDF

Info

Publication number
US3884663A
US3884663A US467443A US46744374A US3884663A US 3884663 A US3884663 A US 3884663A US 467443 A US467443 A US 467443A US 46744374 A US46744374 A US 46744374A US 3884663 A US3884663 A US 3884663A
Authority
US
United States
Prior art keywords
tube
compressor
cylinder
capillary tubes
condenser
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US467443A
Other languages
English (en)
Inventor
Ettore Funaro
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3884663A publication Critical patent/US3884663A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • F25B1/00—Compression machines, plants or systems with non-reversible cycle
    • 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
    • F25B41/30—Expansion means; Dispositions thereof
    • F25B41/385—Dispositions with two or more expansion means arranged in parallel on a refrigerant line leading to the same evaporator

Definitions

  • ABSTRACT A refrigerant system with mechanical compression and refrigeration cycle wherein the refrigerant is expanded through a set of capillary tubes of which the length is adjustable in response to a temperature transducer located within the evaporator section of the system.
  • the means for regulating the capillary tubes length comprises a threaded cylinder slidably received within a tube, the trough of the screw thread functioning as a capillary tube.
  • the system further comprises a trap means for capturing any liquid refrigerant escaping through the capillary tubes when the compressor is not running and for circulating the captured liquid refrigerant when the compressor is re-started.
  • the present invention relates to a mechanical compression refrigeration system with vapor-compression cycle in which the refrigerant fluid at its liquid state is supplied from a separator-receiver tank to the evaporator through the following components:
  • a regulating unit of the refrigerant flow rate which functions to change the flow resistance of the refrigerant by mechanically changing the length of a set of capillary tubes in parallel to one the others in response to changes of the condenser temperature;
  • a solenoid controlled valve at the outlet of said regulating unit which is controlled simultaneously with the compressor motor, which valve is closed when the compressor is not running;
  • a siphon suitably connected to a collecting tank which functions to avoid any piston knocking at the compressor due to the presence of liquid refrigerant therein.
  • said refrigerant regulating unit is controlled by an electromechanism which, at its turn, is piloted by a sensing element of the condenser temperature.
  • capillary tubes also as they are presently employed have drawbacks which limit their use in refrigeration plants.
  • the aim of this invention is to maintain all the practical advantages of the capillary tubes expansion while eliminating the drawbacks, that is to attain a coefficient of performance of the system very close to the nominal coefficient pertaining to the ideal cycle operating between the same evaporation and condensation temperature whatever may be the environment temperature by which the condensation temperature is conditioned.
  • Another object of the invention is to provide a device adapted for functioning as a set of controllable capillary tubes which device, from the standpoint of operation life, is extremely reliable due to the absence of wearable components.
  • a further object of the invention is to provide an electromechanical control means adapted for actuating said flow regulating device in accordance with the temperature of the condensing space.
  • FIG. 1 shows a schematic diagram of refrigeration system with expansion valve
  • FIG. 2 shows a diagram of a refrigeration system with capillary tube expansion
  • FIG. 3 shows a diagram of a refrigeration system according to this invention
  • FIG. 4 shows in detail the flow regulating device and the related actuating mechanism
  • FIG. 5 shows a detailed view of the syphon associated I to the collecting tank
  • FIG. 6 shows a diagram of the electric circuit for controlling the device of FIG. 4;
  • FIG. 7 is an end view of the refrigeration system of FIG. 3 as seen from the high pressure side;
  • FIG. 8 is a side view of the refrigeration system of FIG. 3;
  • FIG. 9 is an end view of the refrigeration system of FIG. 3 as seen from the high pressure side, the louver being removed therefrom.
  • the cycle of both systems is the vaporcompression cycle that is: a fluid at its gaseous state (in general ammonia, Freon or methylchloride) is taken in by a compressor, its volume is reduced by compression and its temperature is increased; from the compressor the fluid is fed to an air or water cooled condenser wherein it is cooled and liquefied at constant pressure.
  • the refrigerant from the condenser is collected at its liquid state into a receiver tank and therefrom it is supplied to an expansion valve and from this to an evaporator wherein it suddenly expands and is reverted to its gaseous state by heat transferred to it from the space to be refrigerated. From the evaporator the gaseous refrigerant returns to the compressor and the cycle starts up again.
  • a refrigeration system provided with expansion valve specifically comprises a compressor 1, a suction line 2 to compressor, a discharge line 3 from the compressor, a condenser 4, a liquid receiver-separator tank 5, an outlet pipe 6 depending from the top of tank 5 the open end of which reaches nearly the bottom of the tank, an expansion valve 7 and an evaporator coil 8.
  • the purpose of tank 5 into which the still warm refrigerant from condenser 4 is fed is for causing said refrigerant to slowly flow over the inner sides of the tank walls down to the bottom thereof whereby the refrigerant is further cooled down to a value the closest possible to the room temperature.
  • the lower the temperature of the refrigerant outcoming from tank 5 the higher is the efficiency of the plant.
  • a refrigeration system with capillary tubes expansion comprises a compressor 9, a suction line 10, a discharge line 1 l, a condenser 12, a capillary tube 13, a refrigerator 14.
  • the capillary tube 13 Through the capillary tube 13 the refrigerant along the tube section between A and A undergoes a pressure drop the same way as across the expansion valve.
  • the capillary tube is a very simple mechanical component and therefore more reliable and long lasting than an expansion valve, however it has the following disadvantages:
  • the capillary tube is in practice a passage perma nently open between the high pressure and the low pressure sections of the system and therefore there is always a refrigerant flow from the high pressure section to the low pressure section even if the compressor is not be running. As a consequence some amount of liquid refrigerant will invade the refrigerator coil 14. When the compressor starts up again, piston knocking can occur at the compressor which can cause failure of the same. For this reason in such type of systems the charge of refrigerant is reduced to a minimum and the receiver separator tank is suppressed.
  • FIG. 3 It comprises a refrigerant receiver tank 19 to which a condenser 18 is connected and which is provided with a pipe 20 which depends from the top of the tank and reaches with its open end almost the bottom thereof, a compressor 15, a suction line 16 to compressor, a discharge line 17 from compressor and a normally closed solenoid controlled valve 27 included between a regulating device which as will be explained hereinafter functions as a set of adjustable capillary tubes, and a set of fixed capillary tubes 28.
  • a regulating device which as will be explained hereinafter functions as a set of adjustable capillary tubes, and a set of fixed capillary tubes 28.
  • the capillary tubes 28 of which three are shown in FIG. 3 are connected at one end thereof to a vertical conduit 22.
  • Conduit 22 at the lower section thereof between dotted lines 45 and 46 of FIG. is formed as a syphon A which communicates with evaporator 24.
  • Syphon A is connected to a collector vessel 49 by two ways: either through a capillary tube 48 (FIG. 5) and through a solenoid controlled valve which closes when compressor 15 is running and a check valve 47 which opens towards vessel 45 (see arrow in FIGS. 3 and 5) but closes the other way.
  • FIG. 3 the lines which lead from the receiver-separator tank 19 to the regulating device 30 and to capillary tubes 28 are indicated by a continuous thick line.
  • the regulating device substantially comprises a solid cylinder 35 of which two opposed end portions are threaded while a central section is turned down to a diameter smaller than the threaded portions.
  • Cylinder 35 is slidably mounted within a coaxial tube 36 with precision fitting between the screw thread ridge and the inner surface of the tube.
  • Tube 36 at one end thereof the left end in FIG. 4 has a chamber B which communicates with one of the two branches of pipe 20 which terminates at near the bottom of receiver 19.
  • the other end of tube 36 penetrates one wall of a fluid tight housing 42 wherein the electromechanical device is contained for controlling the movement of cylinder 35 along tube 36.
  • Such electromechanical device comprises a motor 41 whose shaft 43 is threadingly fitted through a transverse arm 44 which therefore is moved along the motor shaft 43 when this is turned.
  • Arm 44 is firmly attached to an extension of cylinder 35 and to a slider of a potentiometer so that when arm 44 moves along shaft 43 cylinder 3S and the potentiometer slider are also moved.
  • the center section of tube 36 is provided with two peripheral rows of through holes 37 which when cylinder 35 is moved leftward to end of stroke are both exposed, while when cylinder 35 is moved rightwards the left row is covered by the left threaded section of cylinder 35.
  • Said center section of tube 36 including holes 37 is surrounded by a sleeve 38 which is provided with an outlet pipe 34.
  • the screw threads with which the end sections of cylinder 35 are provided function as a pair of capillary tubes in parallel.
  • the refrigerant flowing through pipe 20 is divided in two streams one of which is inlet into chamber B and the other into housing 42.
  • the refrigerant flows along the grooves of the threaded surface of cylinder 35, any direct flow from the cylinder ends towards the center section of tube 36 being prevented by the precision fitting between the screw thread ridge and the inner surface of tube 36.
  • the clearance between said two elements should be kept as low as 0.05 mm.
  • electric motor 41 is controlled by an element sensitive to temperature which is located at a position where the temperature can be detected of the condensing refrigerant which in the case of an air cooled condenser is the room temperature.
  • the temperature sensing element is made to function as one of the two resistances of one of the two branches of a Wheatstone bridge (see FIG. 6).
  • 50 and 51 are the leads of the electrical source of the bridge; 52, 39, S4 and 55 are the resistances of the same bridge; of said resistances: 39 is the changing resistance of potentiometer 39 included in said electromechanical device; 52, as already mentioned, is the resistance of the temperature sensing element and specifically its resistance coefficient is negative that is its resistance decreases when the temperature increases; 54 and 55 are fixed resistances.
  • the operation of the regulating device is as follows:
  • the above regulating device does not cover the whole range of length of the capillary path to be traversed by the refrigerant. In fact in no case a path of zero length will be required. For this reason, a set of capillary tubes of fixed length is provided which tubes are mounted in parallel with one the others and in series with the regulating device. The latter is designed for adding the required length of capillary path to the fixed length provided by the set of fixed capillary tubes 28.
  • a refrigerator system in which although the refrigerant is expanded through capillary tubes a receiver tank 19 is included between the compressor and the capillary tubes of which tank the advantages have been already explained.
  • a solenoid controlled valve 27 is inserted between the regulating device and the set of capillary tubes 28 which valve is closed when the compressor is not running.
  • Another safety means for preventing any flow of liquid refrigerant towards compressor 15 comprises a collecting tank 49 which is connected to a vertical manifold 22 which communicates with the set of fixed capillary tubes 28.
  • Manifold 22 at its lower section is formed as a siphon (shown in FIG. 5 between dotted lines 45-46) that is the lower section of manifold 22 communicates with a downwardly arcuated pipe section which is followed by an uprising pipe section and by an upwardly arcuated pipe section and by a depending pipe section which is connected to evaporator 24.
  • the lowermost point of the downwardly arcuated pipe section is connected to tank 49 through a normally open valve 29 that is a valve which is open when compressor 15 is not running and a check valve 47.
  • a capillary tube 48 connects a position close to the bottom of tank 49 to a point along said uprising pipe section of said siphon.
  • valve 27 Let us suppose that compressor 15 is not running and some leaking of liquid refrigerant occurs through valve 27. Then there will be a flow of liquid refrigerant to tank 49 through capillary tubes 28, a portion of the downwardly arcuated siphon, valve 29 and valve 47.
  • valve 27 will open and valve 29 will shut. Due to the suction by compressor 15 the pressure within evaporator 24 will be lowered with respect to tank 49.
  • a refrigerator system with mechanical compression and refrigeration cycle comprising a compressor, a condenser connected to a discharge line, an evaporator connected to the suction line to compressor and a set of capillary expansion tubes in parallel to one the other between said condenser and said evaporator, which system further comprises a receiver tank connected to the outlet of condenser which receiver is provided with an outlet pipe of which the open end terminates at nearly the bottom of the receiver and which passes through the top thereof to communicate with a regulating device comprising at least a capillary tube of which the length is adjusted to fit the temperature changes of said evaporator the outlet of said regulating device being connected to one end of said set of capillary tubes of which the other end communicates with a vertical manifold; a siphon being provided at the lower end of said manifold; a collector tank being connected to said siphon at the lowermost point thereof through a check valve and through a capillary tube of which one end terminates at nearly the bottom of said tank and at the other end communicates with
  • said regulating device comprises a solid cylinder of which two opposed end portions separate by a central portion of smaller diameter are threaded; which cylinder is slidably received with precision fitting into a tube of substantially the same length, said tube being provided with two peripheral rows of through holes which communicate with the space between the central section of smaller diameter of said cylinder when the latter is longitudinally centered with respect to said tube, the center section of said tube being enclosed within a cylindrical sleeve which extends at both ends beyond said rows of holes and which defines a fluid tight space around said tube which space communicates with said set of capillary tubes; said tube being closed at one end by a chamber defining cap the other end of said cylinder being open to the inner space of a housing wherein an electromechanism is contained for moving said cylinder in response to changes of the condenser temperature, said chamber and said inner space being both connected to said outlet pipe from the receiver tank.
  • a refrigerator system wherein said electromechanism for moving said cylinder comprises a motor of which the shaft has a threaded extension which engages a threaded bore through a transverse arm of which one end is firmly attached to an extension of said cylinder and the other end is firmly attached to the slider of a potentiometer, the resistance of the latter being included in a Wheatstone bridge as one of the two resistances of a branch thereof while the corresponding resistance of the other branch of the bridge comprises a sensing element of the condenser temperature and the remaining resistances of the bridge are resistances of fixed value, the output of the bridge being connected to a pair of relays adapted for starting the compressor motor in either direction in accordance with the direction of the output current from the bridge.
  • thermoelectric element has a negative coefficient of resistance that is its resistance decreases when the temperature increases.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
  • Temperature-Responsive Valves (AREA)
US467443A 1973-05-08 1974-05-06 Refrigerator system with refrigerant expansion through capillary tubes of adjustable length Expired - Lifetime US3884663A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IT49838/73A IT984949B (it) 1973-05-08 1973-05-08 Impianto frigorifero a capilla re

Publications (1)

Publication Number Publication Date
US3884663A true US3884663A (en) 1975-05-20

Family

ID=11271680

Family Applications (1)

Application Number Title Priority Date Filing Date
US467443A Expired - Lifetime US3884663A (en) 1973-05-08 1974-05-06 Refrigerator system with refrigerant expansion through capillary tubes of adjustable length

Country Status (10)

Country Link
US (1) US3884663A (fr)
JP (1) JPS5755115B2 (fr)
BE (1) BE814736A (fr)
CA (1) CA1004866A (fr)
DE (1) DE2422278C2 (fr)
FR (1) FR2229027B3 (fr)
GB (1) GB1466428A (fr)
IL (1) IL44785A (fr)
IT (1) IT984949B (fr)
ZA (1) ZA742949B (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4286438A (en) * 1980-05-02 1981-09-01 Whirlpool Corporation Condition responsive liquid line valve for refrigeration appliance
US4563879A (en) * 1984-05-23 1986-01-14 Mitsubishi Denki Kabushiki Kaisha Heat pump with capillary tube-type expansion device
US5231847A (en) * 1992-08-14 1993-08-03 Whirlpool Corporation Multi-temperature evaporator refrigerator system with variable speed compressor
WO2009002256A1 (fr) * 2007-06-25 2008-12-31 Alfa Laval Corporate Ab Dispositif de distribution de liquide se détendant
DE102013216364A1 (de) 2013-08-19 2015-02-19 BSH Bosch und Siemens Hausgeräte GmbH Kältegerät mit einer verstellbaren Drosselung
US9221067B2 (en) 2013-06-18 2015-12-29 Cleanlogic Llc CO2 composite spray method and apparatus
CN112797677A (zh) * 2021-01-26 2021-05-14 青岛海尔空调电子有限公司 选择制冷系统用毛细管的装置及方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102553285B (zh) * 2012-01-12 2017-02-15 中国林业科学研究院林产化学工业研究所 一种毛细冷凝原理、工艺及其设备

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2148413A (en) * 1935-03-12 1939-02-21 Westinghouse Electric & Mfg Co Refrigerating apparatus
US2532019A (en) * 1949-04-15 1950-11-28 Standard Refrigeration Company Pressure reducing device for refrigerating apparatus
US2807940A (en) * 1954-03-17 1957-10-01 Gen Electric Refrigeration system
US3677028A (en) * 1970-12-01 1972-07-18 Carrier Corp Refrigeration system

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB686406A (en) * 1949-04-15 1953-01-21 Standard Rrfrigeration Company Pressure reducing or flow restricting device for refrigerating apparatus
US3364692A (en) * 1966-12-29 1968-01-23 Westinghouse Electric Corp Refrigeration systems having aircooled condenser coils
US3577743A (en) * 1969-06-10 1971-05-04 Vilter Manufacturing Corp Control for refrigeration systems

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2148413A (en) * 1935-03-12 1939-02-21 Westinghouse Electric & Mfg Co Refrigerating apparatus
US2532019A (en) * 1949-04-15 1950-11-28 Standard Refrigeration Company Pressure reducing device for refrigerating apparatus
US2807940A (en) * 1954-03-17 1957-10-01 Gen Electric Refrigeration system
US3677028A (en) * 1970-12-01 1972-07-18 Carrier Corp Refrigeration system

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4286438A (en) * 1980-05-02 1981-09-01 Whirlpool Corporation Condition responsive liquid line valve for refrigeration appliance
US4563879A (en) * 1984-05-23 1986-01-14 Mitsubishi Denki Kabushiki Kaisha Heat pump with capillary tube-type expansion device
US5231847A (en) * 1992-08-14 1993-08-03 Whirlpool Corporation Multi-temperature evaporator refrigerator system with variable speed compressor
WO2009002256A1 (fr) * 2007-06-25 2008-12-31 Alfa Laval Corporate Ab Dispositif de distribution de liquide se détendant
US9221067B2 (en) 2013-06-18 2015-12-29 Cleanlogic Llc CO2 composite spray method and apparatus
DE102013216364A1 (de) 2013-08-19 2015-02-19 BSH Bosch und Siemens Hausgeräte GmbH Kältegerät mit einer verstellbaren Drosselung
CN112797677A (zh) * 2021-01-26 2021-05-14 青岛海尔空调电子有限公司 选择制冷系统用毛细管的装置及方法
CN112797677B (zh) * 2021-01-26 2023-08-15 青岛海尔空调电子有限公司 选择制冷系统用毛细管的装置及方法

Also Published As

Publication number Publication date
FR2229027A1 (fr) 1974-12-06
BE814736A (fr) 1974-09-02
JPS5755115B2 (fr) 1982-11-22
ZA742949B (en) 1975-05-28
FR2229027B3 (fr) 1977-05-06
IL44785A0 (en) 1974-07-31
IT984949B (it) 1974-11-20
IL44785A (en) 1977-10-31
AU6874574A (en) 1975-11-13
JPS5048538A (fr) 1975-04-30
GB1466428A (en) 1977-03-09
DE2422278C2 (de) 1986-04-30
CA1004866A (en) 1977-02-08
DE2422278A1 (de) 1974-11-28

Similar Documents

Publication Publication Date Title
US5136855A (en) Heat pump having an accumulator with refrigerant level sensor
US5752390A (en) Improvements in vapor-compression refrigeration
KR890004395B1 (ko) 냉동 사이클 장치
US4136528A (en) Refrigeration system subcooling control
US6430947B2 (en) Mobile air conditioning system and control mechanism therefor
US4257795A (en) Compressor heat pump system with maximum and minimum evaporator ΔT control
USRE30499E (en) Injection cooling of screw compressors
IE42343B1 (en) "improved refrigeration systems"
US3667247A (en) Refrigeration system with evaporator outlet control valve
US3824802A (en) Control means for accumulator throttling device
US3817053A (en) Refrigerating system including flow control valve
US3651657A (en) Air conditioning system with suction accumulator
US4032070A (en) Thermostatic expansion valve for refrigeration installations
US3884663A (en) Refrigerator system with refrigerant expansion through capillary tubes of adjustable length
US3435626A (en) Pressure control apparatus for refrigeration system
US4982574A (en) Reverse cycle type refrigeration system with water cooled condenser and economizer feature
JPH09229497A (ja) 冷凍サイクル
US5031416A (en) Variable area refrigerant expansion device having a flexible orifice
US5025640A (en) Refrigerant expansion device for optimizing cooling and defrost operation of a heat pump
US4081971A (en) Air cooled centrifugal refrigeration machine with provision to prevent evaporator freezing
US3609990A (en) Refrigeration accumulator
JP2009186033A (ja) 二段圧縮式冷凍装置
US3449923A (en) Refrigerant feed control and systems
US3054273A (en) Thermal expansion valve
US3740961A (en) Open cycle ammonia refrigeration system