US3320763A - Controls for refrigeration systems - Google Patents

Controls for refrigeration systems Download PDF

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Publication number
US3320763A
US3320763A US508736A US50873665A US3320763A US 3320763 A US3320763 A US 3320763A US 508736 A US508736 A US 508736A US 50873665 A US50873665 A US 50873665A US 3320763 A US3320763 A US 3320763A
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United States
Prior art keywords
valve
pressure
liquid
pilot valve
evaporator
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
US508736A
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English (en)
Inventor
James R Harnish
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.)
YORK-LUXAIRE Inc A CORP OF DE
Original Assignee
Westinghouse Electric Corp
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 Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US508736A priority Critical patent/US3320763A/en
Priority to GB46445/66A priority patent/GB1126496A/en
Priority to DE1501175A priority patent/DE1501175C3/de
Priority to FR84170A priority patent/FR1516006A/fr
Application granted granted Critical
Publication of US3320763A publication Critical patent/US3320763A/en
Assigned to YORK-LUXAIRE, INC., A CORP. OF DE. reassignment YORK-LUXAIRE, INC., A CORP. OF DE. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WESTINGHOUSE ELECTRIC CORPORATION
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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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
    • F25B41/00—Fluid-circulation arrangements
    • F25B41/30—Expansion means; Dispositions thereof
    • F25B41/31—Expansion valves
    • F25B41/33—Expansion valves with the valve member being actuated by the fluid pressure, e.g. by the pressure of the refrigerant
    • F25B41/335—Expansion valves with the valve member being actuated by the fluid pressure, e.g. by the pressure of the refrigerant via diaphragms
    • 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
    • F25B2600/00—Control issues
    • F25B2600/02—Compressor control
    • F25B2600/025—Compressor control by controlling speed
    • F25B2600/0251—Compressor control by controlling speed with on-off operation
    • 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
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2513—Expansion valves
    • 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
    • F25B49/025—Motor control 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
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D2700/00—Means for sensing or measuring; Sensors therefor
    • F25D2700/16—Sensors measuring the temperature of products

Definitions

  • a feature of this invention is that a relatively small, sub-cooling control valve operates as a pilot valve to control a relatively large expansion valve during normal operation, with the sub-cooling control valve shunted by a relatively small automatic expansion valve which operates as a pilot valve to control the expansion valve during abnormal operation when the condensing pressure is insufiicient to properly operate the sub-cooling control valve.
  • the over-load control setting of a compressor motor, and the high pressure cut-out setting may be critical because of pull-down requirements during warm start-ups when the outdoor ambient temperature is relatively high, and one or both of such controls may turn the compressor motor off.
  • a relatively small, automatic expansion valve responsive to the evaporator pressure is located in the control line of the previously mentioned, large expansion valve, and operates t adjust the expansion valve to starve the evaporator for preventing excessive pressures during such warm startups.
  • An object of this invention is to use a relatively small, sub-cooling control valve to control a relatively large expansion valve in a refrigeration system.
  • Another object of this invention is to use a relatively small, automatic expansion valve to control a relatively large expansion valve in a refrigeration system.
  • Another object of this invention is to use a relatively small, sub-cooling control valve, shunted by a, relatively small, automatic expansion valve, to control a relatively large expansion 'valve in a refrigeration system.
  • Another object of this invention is to prevent excessive refrigerant pressures in a refrigeration system during warm start-ups at high outdoor ambient temperatures.
  • FIG. 1 is a diagrammatic view of a refrigeration system embodying this invention
  • FIG. 2 is an enlarged side section of the automatic expansion valve of FIG. 1;
  • FIG. 3 is an enlarged, side section of the sub-cooling control valve of FIG. 1, and
  • FIG. 4 is an enlarged side section of the main expan .sion valve of FIG. 1.
  • a conventional, hermetic, refrigerant compressor C having an enclosed electric motor CM is connected by discharge gas tube 10 to one end of condenser coil 11, the other end of which is connected by liquid tube 12, through a heat exchange coil which is not shown, within accumulator 13, to the inlet of main expansion valve 14.
  • the outlet of the valve 14 is connected by tube 15 to one end of evaporator coil 16, the other end of which is connected by tube 17 to the top of the accumulator 13.
  • the accumulator 13 is connected by suction gas tube 18 to the suction side of the compressor C.
  • the tube 12 is also connected between the accumulator 13 and the expansion valve 14 to tube 20 which is connected through valve 21 to the inlets of sub-cooling control valve 22 and automatic expansion valve 23 operating as pilot valves.
  • the outlets of the valves 22 and 23 are connected by tube 24 through solenoid-operated valve 25 to the top of piston chamber 26 of the main expansion valve 14.
  • the valve 23 has a diaphragm chamber '30 with a diaphragm 31 extending across its center.
  • the interior of the chamber 30 below the diaphragm 31 is connected by capillary tube 32 to the tube 17.
  • the valve 23 has a partition 34 extending across its interior between its inlet and outlet, with a valve opening 35 therein.
  • a valve piston '36 below the opening 35 is connected by piston rod 37 to the center of the diaphragm 31.
  • a coiled spring 38 extends between the center of the top of the diaphragm 31 and the top of the chamber 30, and biases the piston 36 towards open position.
  • the valve 21 is similar to the valve 23 except that it is adjusted to close at a different pressure as will be described later, and has a diaphragm chamber 39, the lower portion of which is connected by a capillary tube 40 to the tube 32.
  • the sub-cooling control valve 22 has a diaphragm chamber 41 with a diaphragm 42 extending across its center. It has a partition 43 extending across its interior between its inlet and outlet, with a valve opening 44 therein.
  • a valve piston 45 above the opening 44 is connected by piston rod 46 to the center of the diaphragm 42.
  • a coiled spring 47 extends around the rod 46 between the bottom of the chamber 41 and the top of the valve piston 45, and biases the piston 45 towards closed position.
  • the interior of the chamber 41 above the diaphragm 42 is connected by capillary tube 50 toa conventional thermal bulb 51 in heat exchange contact with the tube 12 between the accumulator 13 and the coil 11.
  • the interior of the chamber 41 below the diaphragm 42 is connected by capillary tube 52 to the interior of the tube 12 adjacent to the bulb 51.
  • the piston chamber 26 of the main expansion valve 14 has a piston 55 slidable therein.
  • a partition 56 extends across the interior of the valve 14 between its inlet and outlet and has a valve opening 57 therein.
  • a valve piston 58 below the opening 57 is connected by piston rod 59 to the center of the piston 55.
  • a coiled spring 60 extends between the bottom of the piston 58 and the bottom of the valve 14, and biases the piston 58 towards closed position.
  • the piston 55 has a pressure equalizing passage 61 extending therethrough.
  • a solenoid 65 is connected to the valve 25 to open and close the latter.
  • the compressor motor CM is connected to electric supply line L1, and through switch S1 of motor starter MS, and wire 66 to electric supply line L2.
  • the starter MS is connected through switch TS of thermostat T, and wires 67 and 68 to the lines L1 and L2.
  • the solenoid 65 is connected by wire 69 and the wire 66 to the line L2, and is connected by wire I 76 and switch S2 of the starter MS to the line L1.
  • the thermostat T When the thermostat T calls for cooling, it closes its switch TS which energizes the motor starter MS. The latter closes its switches S1 and S2.
  • the closed switch S1 energizes the compressor motor CM, starting the compressor C.
  • the closed switch S2 energizes the solenoid 65 which opens the valve 25.
  • the compressor C supplies discharge gas through the tube 11) into the condenser coil 11. Refrigerant liquid flows from the coil 11 through the tube 12 and the heat exchange coil (not shown) within the accumulator 13, into the expansion valve 14 which meters refrigerant to the evaporator coil 16. Gas and unevaporated liquid from the coil 16 flow through the tube 17 into the accumulator 13. Gas separated from the liquid within the accumulator 13 flows through the suction gas tube 18 to the suction side of they compressor C.
  • the valve 21 is adjusted to be open during normal operation so as to permit liquid to flow from the tube 12 into the inlets of the pilot valves 22 and 23. It may be set to start to close when the pressure of the refrigerant leaving the evaporator coil 16 in a system using F22 refrigerant increases, for example, above 84 p.s.i. as will be described later.
  • the pilot valve 23 is adjusted to be closed during normal operation when the evaporator pressure is normal, and to open when the evaporator coil 16 is about to become starved as will be described later.
  • the sub-cooling control valve 22 adjust the expansion valve 14 to meter refrigerant to the evaporator coil 16 at the rate at which refrigerant is condensed in the condenser coil 11 while maintaining, for example, F. subcooling at a condensing temperature of 100 F.
  • An increase in the temperature of the liquid in the tube 12 at the bulb 51 acts through the bulb 51, the capillary tube 50 and the diaphragm 42 of the valve 22, to adjust the piston 45 of the valve 22 towards closed position, reducing the'liquid pressure above the piston 55 of the valve 14, and causing the valve piston 58 of the valve 14 to move towards closed position so as to back up more liquid within the condenser coil 11, for increasing the sub-cooling of the liquid.
  • Increased liquid pressure in the tube 12 where the capillary tube 52 is connected-to the latter acts through the tube 52 and the diaphragm 42 to adjust the valve piston 45 of the valve 22 towards open position, increasing the liquid pressure above the piston 55 of the valve 14, and causing the valve piston 58 of the valve 14 to move towards open position.
  • the valve 14 is not sufficiently open, liquid in the coil 11 will back up until the pressure is increased sutficiently or the temperature is reduced sufliciently to cause the valve 22 to adjust the valve 14 towards open position, and vice versa.
  • valve 22 readjusts the valve 14 accordingly, but the latter meters refrigerant to the evaporator coil 16 at the rate at which refrigerant is condensed in the condenser coil 11.
  • the valve 14 continuously overfeeds the evaportor coil 16 as disclosed in the previously mentioned application.
  • the liquid subcooling at the bulb 51 may be insufiicient for the valve 22 to adjust the expansion valve 14.sufi"1ciently open to prevent the evaporator coil 16 from becoming starved.
  • the pilot valve 23 responds through the capillary tube 32 to the resulting reduced pressure of the refrigerant within the tube 17 at the outlet of the evaporator coil 16, the reduced pressure below the diaphragm 31 of the valve 23, permitting the spring 38 to move the piston 36 to open position, supplying liquid above the piston 55 of the valve 14 to cause the valve piston 58 of the valve 14 to open sulficiently to provide sufiicient refrjgerant to the evaporator coil 16 to prevent it from becoming starved.
  • the bleed passage 61 in the piston 55 of the valve 14 permits pressure in the chamber above the piston 55 to equalize the evaporator pressure when the valve 22 or the valve 23 moves towards closed position, by flowing through the passage 61 :and the interior of the valve 14 into its outlet, thus permitting the spring 60 to move the valve piston 58 of the valve 14 towards closed position.
  • the chilled water temperature may be 90 F. or even higher.
  • the condenser would be sized to operate at an outdoor air temperature of about F., but only when the temperature of thechilled water leaving the chiller is at, say, 50 F. Consequently, warm start-ups during high outdoor ambient temperatures, may result in the compressor motor being tripped out by an overload control or by a high pressure cut-out.
  • the valve 21 prevents this.
  • the thermostat T When the thermostat T is satisfied, it opens its switch TS, deenergizing the motor starter MS which opens its switch S1, stopping the compressor motor CM. At the same time, the switch S2 of the starter MS opens, deenergizing the solenoid 65 which closes the valve 25 in the control tube 24 of the expansion valve 14, shutting off the supply of liquid to the piston chamber 26 of the valve 14 so that the spring 60 closes the valve piston 58. of'the valve 14, providing positive shutoff when the system is turned off.
  • valves 21., 22, 23 and 25 are in the liquid supply to the piston chamber 26 of the expansion valve 14, they can be relatively small valves, for example, three ton valves for controlling a one hundred ton valve 14.
  • a pilot valve having an inlet connected to said circuit between said condenser and said expansion valve to receive refrigerant liquid from said circuit, said pilot valve having an out let, said pilot valve having means including means responsive to the pressure and the temperature of the refrigerant liquid leaving said condenser for opening and closing said pilot valve, said expansion valve having a chamber connected to said outlet of said pilot valve for receiving refrigerant liquidv from said pilot valve 'when said pilot valve is open, and means including means responsive to the pressure of the liquid entering said 2.
  • the invention claimed in claim 1 in which there is provided a second pilot valve having an inlet connected to said inlet of said first mentioned pilot valve and having an outlet connected to said outlet of said first mentioned pilot valve, and in which said second pilot valve has means including means responsive to the pressure of the refrigerant at said evaporator for opening said second pilot valve on a decrease in the pressure of the refrigerant at said evaporator and for closing said second pilot valve on an increase in the pressure of the refrigerant at said evaporator.
  • a pilot valve having an inlet connected to said circuit between said condenser and said expansion valve to receive refrigerant liquid from said circuit, said pilot valve having an outlet, said pilot valve having means including means responsive to the pressure of the refrigerant at said evaporator for opening said pilot valve on a decrease in the pressure of the refrigerant at said evaporator and for closing said pilot valve on an increase in the pressure of the refrigerant at said evaporator, said expansion valve having a chamber connected to said outlet of said pilot valve for receiving refrigerant liquid from said pilot valve when said pilot valve is open, and means including means responsive to the pressure of the liquid entering said chamber for adjusting said expansion valve towards open position on an increase in the pressure of the liquid entering said chamber and for adjusting said expansion valve towards closed position on a decrease in the pressure of the liquid entering said chamber.

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  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
  • Temperature-Responsive Valves (AREA)
US508736A 1965-11-19 1965-11-19 Controls for refrigeration systems Expired - Lifetime US3320763A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US508736A US3320763A (en) 1965-11-19 1965-11-19 Controls for refrigeration systems
GB46445/66A GB1126496A (en) 1965-11-19 1966-10-18 Controls for refrigeration systems
DE1501175A DE1501175C3 (de) 1965-11-19 1966-11-16 Kühlanlage mit einem dem Verdampfer vorgeschalteten Drosselventil
FR84170A FR1516006A (fr) 1965-11-19 1966-11-18 Dispositif de réglage pour systèmes de réfrigération

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US508736A US3320763A (en) 1965-11-19 1965-11-19 Controls for refrigeration systems

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US3320763A true US3320763A (en) 1967-05-23

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ID=24023861

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Application Number Title Priority Date Filing Date
US508736A Expired - Lifetime US3320763A (en) 1965-11-19 1965-11-19 Controls for refrigeration systems

Country Status (4)

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US (1) US3320763A (de)
DE (1) DE1501175C3 (de)
FR (1) FR1516006A (de)
GB (1) GB1126496A (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3592018A (en) * 1969-08-11 1971-07-13 Gen Motors Corp Pilot operated automatic expansion valve
US3638446A (en) * 1969-06-27 1972-02-01 Robert T Palmer Low ambient control of subcooling control valve
US3754730A (en) * 1972-05-01 1973-08-28 Refrigerating Specialties Co Pressure refrigerant regulator
WO1999011987A1 (en) * 1997-08-28 1999-03-11 Empresa Brasileira De Compressores S.A. - Embraco A refrigeration circuit arrangement for a refrigeration system
US20210180842A1 (en) * 2016-10-28 2021-06-17 Mitsubishi Electric Corporation Air conditioner

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006041156A1 (de) * 2006-09-01 2008-03-06 Volkswagen Ag Kältemittel-Kreislauf für eine Fahrzeug-Klimaanlage

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2571625A (en) * 1943-12-14 1951-10-16 George E Seldon Thermal and auxiliary valve combination
US3123591A (en) * 1964-03-03 Fractionation of polymerization diluent

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3123591A (en) * 1964-03-03 Fractionation of polymerization diluent
US2571625A (en) * 1943-12-14 1951-10-16 George E Seldon Thermal and auxiliary valve combination

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3638446A (en) * 1969-06-27 1972-02-01 Robert T Palmer Low ambient control of subcooling control valve
US3592018A (en) * 1969-08-11 1971-07-13 Gen Motors Corp Pilot operated automatic expansion valve
US3754730A (en) * 1972-05-01 1973-08-28 Refrigerating Specialties Co Pressure refrigerant regulator
DE2320499A1 (de) * 1972-05-01 1973-11-15 Refrigerating Specialties Co Druckregler fuer kuehlmittel
WO1999011987A1 (en) * 1997-08-28 1999-03-11 Empresa Brasileira De Compressores S.A. - Embraco A refrigeration circuit arrangement for a refrigeration system
US20210180842A1 (en) * 2016-10-28 2021-06-17 Mitsubishi Electric Corporation Air conditioner

Also Published As

Publication number Publication date
GB1126496A (en) 1968-09-05
DE1501175B2 (de) 1974-04-25
DE1501175A1 (de) 1969-10-23
DE1501175C3 (de) 1974-11-28
FR1516006A (fr) 1968-03-08

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Legal Events

Date Code Title Description
AS Assignment

Owner name: YORK-LUXAIRE, INC., 200 S. MICHIGAN AVENUE, CHICAG

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WESTINGHOUSE ELECTRIC CORPORATION;REEL/FRAME:003914/0191

Effective date: 19810921

Owner name: YORK-LUXAIRE, INC., A CORP. OF DE., ILLINOIS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:WESTINGHOUSE ELECTRIC CORPORATION;REEL/FRAME:003914/0191

Effective date: 19810921