Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3736763 A
Publication typeGrant
Publication dateJun 5, 1973
Filing dateSep 3, 1971
Priority dateSep 3, 1971
Publication numberUS 3736763 A, US 3736763A, US-A-3736763, US3736763 A, US3736763A
InventorsM Garland
Original AssigneeFrick Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Condenser pressure control apparatus
US 3736763 A
Abstract
Non-condensable gas in a storage chamber is introduced into a refrigeration system to maintain condenser pressure above a desired minimum, and is permitted to escape from the refrigeration system back to the storage chamber to relieve high condenser pressures. Pressure responsive switches monitor the high side of the refrigeration system and control the flow of the non-condensable gas into and out of the refrigeration system.
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

United States Patent 1 Garland June 5, 1973 CONDENSER PRESSURE CONTROL APPARATUS Milton W. Garland, Waynesboro, Pa.

Assignee: Frick Company, Waynesboro, Pa.

Filed: Sept. 3, 1971 Appl. No.: 177,548

Inventor:

US Cl. ..62/85, 62/149, 62/174, 62/196 Int. Cl ..F25b 41/00 Field of Search ..62/l95, 196, 149, 62/174, 85, 475

References Cited UNITED STATES PATENTS 9/1960 Etherington ..62/149 3/1970 Norton ..62/1 74 Primary ExaminerMeyer Perlin Attorney-A. Yates Dowell, Jr.

[57] ABSTRACT Non-condensable gas in a storage chamber is introduced into a refrigeration system to maintain condenser pressure above a desired minimum, and is permitted to escape from the refrigeration system back to the storage chamber to relieve high condenser pressures. Pressure responsive switches monitor the high side of the refrigeration system and control the flow of the non-condensable gas into and out of the refrigeration system.

6 Claims, 2 Drawing Figures CONDENSER PRESSURE CONTROL APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention This application relates to control of pressures within the high side of a refrigeration system. Specifically, it relates to apparatus for introducing a non-condensable gas into the high side of a refrigeration system and permitting the escape of the same from the system in order to maintain condenser pressure at a desired level.

2. Description of the Prior Art Various methods for controlling pressure within the high side of refrigeration units have been devised to increase the efficient functioning of such units. In the US Pat. No. 3,499,298 to Norton, a non-condensable gas is stored under pressure in a chamber which is connected to the high side of a refrigeration apparatus by a fluid line. During normal operation, the fluid line is continuously open. Thus, no automatic means is provided to relieve condenser pressure by isolating the non-condensable gas from the refrigeration unit.

SUMMARY OF THE INVENTION The present invention is an apparatus for controlling condenser pressure in a compression refrigeration unit. A storage tank for non-condensable gas is provided together with fluid lines which connect the storage tank to the refrigeration unit. Pressure responsive switches monitor condenser pressure in the refrigeration unit and operate control valves which regulate gas flow through the fluid lines. When condenser pressure falls to a desired minimum, a pressure switch causes a first valve to open and permit introduction of noncondensable gas into the high side of the refrigeration unit thereby raising the condenser pressure. This valve is closed by the pressure switch when condenser pressure rises to a predetermined level.

When condenser pressure rises to a desired maximum, a pressure switch causes another pressure valve to open and permit the flow of non-condensable gas from the high side of the refrigeration unit back into the storage tank thereby relieving condenser pressure. This valve is closed when condenser pressure falls to a predetermined level which indicates that substantially all of the non-condensable gas but substantially none of the refrigerant vapor has passed out of the refrigeration unit. Non-condensable gas may not again reenter the refrigeration unit until condenser pressure drops to the desired minimum at which the first valve is caused to open. When the non-condensable gas is thus isolated, it cannot operate to boost condenser pressures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic showing the invention. FIG. 2 is an electrical diagram.

DESCRIPTION OF THE PREFERRED EMBODIMENT A refrigeration system as shown in FIG. 1 has a compressor powered by an electric motor 28. The compressor draws refrigerant vapor through suction line 1 1 and discharges it into line 12 on the high side of the system. The vapor is liquefied in condenser 13 and passes through line 15 to receiver 16. From the bottom of the receiver 16 the flow is through line 17 and expansion valve 19 into the low side of the system including evaporator 20, evaporator discharge line 22, and suction line 11. When the compressor is shut off, a solenoid controlled valve 21 in fluid line 17 is closed in order to keep the evaporator 20 from becoming flooded.

In accordance with the invention, a condenser pressure maintaining device is incorporated in the refrigeration system described above. The pressure maintaining device includes a reserve tank 33 which is initially charged with a stable non-condensable gas, such as dry nitrogen. The pressure of the non-condensable gas in the reserve tank 33 is less than the desired maximum condenser pressure, for example, less than 200 PSIG but greater than the rated evaporator pressure of for example 50 PSIG in a refrigeration system using freon 22. The volume of the reserve tank 33 is large enough so that when the non-condensable gas is introduced into the refrigeration system, the reserve tank pressure does not drop to 50 PSIG. Accordingly, the reserve tank volume may, for example, equal the sum of the volumes of the condenser 13 and receiver 16 with a non-condensable gas pressure of 150 PSIG.

A fluid line 35 connects the top of the reserve tank to the compressor suction line 11. Gas flow through line 35 is controlled by a solenoid operated valve 37 in line 35. A second fluid line 32 connects the top of reserve tank 33 to the top of the receiver 16. A solenoid operated valve 39 controls flow through line 32. An adjustable pressure operated switch 38 is provided to monitor condenser pressure and accordingly is suitably connected in line 32. This switch controls the operation of solenoid valve 37. Similarly a second adjustable pressure switch 40 is provided to monitor the pressure in line 32 and to operate solenoid valve 39. A pressure gauge 34 is provided to monitor the reserve tank 33. Thus the pressure maintaining device, according to the invention, provides a reserve compartment for noncondensable gas under pressure and such gas may pass out of the reserve tank through line 35 to the suction line 11 or into the reserve tank through a receiver attached line 32.

FIG. 2 shows the electrical hookup for the refrigeration system and pressure maintaining device discussed above. Lines 41 and 42 are power lines which are connected by a pair of lines 43 and 44. In line 43 are located in series a master control switch 45, a thermostat switch 46, a motor 28, and motor overload breakers 47 and 48. Along the line 44 are arranged in series a pair of contacts 49 that close when the motor begins operation, and a relay coil 50. The relay coil 50 operates associated relay contacts 51, 52 and 53.

A line 54 is interposed in line 44 between contacts 49 and relay coil 50 and has three branch lines 55, 56 and 57 connected to power line 42. Solenoid 60 for operating valve 21 is located in branch line in series with relay contact 51. Solenoid 61 for operating valve 37 is located in branch line 56 in series with relay contact 52 and pressure switch 38. Solenoid 62 for operating valve 39 is located on branch line 57 in series with relay contact 53 and pressure switch 40.

The refrigeration system is started by closing master control switch 45 so that current may pass between lines 41 and 42 through thermostat switch 46, normally closed at high temperatures, through compressor motor 28 activating the same, and through normally closed motor overload breakers 47 and 48. When motor 28 starts operation, contacts 49 close thus activating relay coil 50 which closes associated relay contacts 51, 52 and 53. Current flows through solenoid causing the valve 21 to open and also flows through to pressure activated switches 38 and 40 in series with solenoids 61 and 62 which operate valves 37 and 39, respectively.

During a certain period of the year, such as winter, ambient air temperatures surrounding the condenser 13 may be so low as to cause pressure within the high side of the refrigeration unit, i.e., condenser pressure, to fall below a desired minimum, as for example, below 150 PSIG. Below 150 PSIG, an insufficient pressure differential across expansion valve 19 exists and tends to deprive the evaporator of refrigerant.

At a preselected pressure of, say, 150 PSIG, pressure switch 38 is set to close causing the solenoid valve 37 to open so that the non-condensable gas in reserve chamber 33 is permitted to pass into suction line 11. The compressor pumps the non-condensable gas into the high side together with refrigerant vapor from discharge line 22. In the high side the non-condensable gas displaces refrigerant vapors thereby raising the condenser pressure. As the refrigeration system continues to operate, the non-condensable gas moves through the condenser and accumulates in receiver 16 having a possible exit only through closed line 32 which leads back into the reserve tank 33.

After pressure within the high side of the refrigeration unit rises to a predetermined level, for example, about 160 PSIG, the pressure switch 38 is set to open and cause the solenoid valve 37 to close, thus stopping the flow of non-condensable gas from the reserve tank 33 into the suction line 11. Thus the partial pressure of the non-condensable gas introduced into the high side raises the condenser pressure by 10 pounds from 150 P816 to 160 PSIG.

During summer, for example, high temperature ambient air conditions may cause condenser pressure to increase to 180 P810 or higher. At a preselected pressure of, say, 180 PSIG, the'pressure switch 40 is set to close causing solenoid valve 39 to open thereby relieving condenser pressure and allowing non-condensable gas trapped in the top of the receiver 16 to pass through line 32 and into the reserve tank 33. Solenoid valve 39 remains open continuously when ambient temperature conditions maintain a condenser pressure of 180 PSIG or higher thereby relieving condenser pressure into the reserve tank 33.

When solenoid valve 39 is open for an extended time, the pressures within the reserve tank 33 and receiver 16 tend to equalize. However, if substantially all of the non-condensable gas in the receiver has passed into the reserve tank but the reserve tank pressure is insufficient to balance the receiver pressure, refrigerant vapor may pass through line 32 and into the reserve tank until generally equal pressures are achieved. As condenser pressure decreases, refrigerant vapor within the reserve tank passes back into the receiver 16 since vapor pressure within the receiver 16 is lower than vapor pressure in the reserve tank 33. The noncondensable gas, however, tends to remain in the reserve tank 33.

After pressure within the high side of the refrigeration system falls a predetermined amount, for example, in this embodiment of the invention approximately 10 pounds below 180 PSlG to 170 PSIG, pressure switch dil is set to open thereby causing solenoid valve 39 to close and shut off the flow of gas from the receiver 16 into the reserve tank 33 through line 32. Note that the pressures without the pressure boosting effect of the non-condensable gas until the condenser pressure again drops to PSIG at which solenoid valve 37 is set to open. Compressor power requirements and wear on the various parts of the refrigeration system are decreased accordingly.

I claim:

1. In a refrigeration system having a high pressure side and a low pressure side, means for raising the pressure of refrigerant fromv the low pressure side to the high pressure side, and means for condensing and receiving condensed refrigerant in the high pressure side, the improvement comprising, means for maintaining the level of pressure in the condensing and receiving means within a predetermined range, said pressure level maintaining means comprising storage vessel means having a first connection to the low pressure side adjacent to the pressure raising means and a second connection to the receiving means, a gas which is noncondensable in the system within the storage vessel means, and first and second valve means for selectively opening and closing said first and second connections to permit selective release of the non-condensable gas from the vessel means into the pressure raising means for discharge into the condensing and receiving means when the pressure level therein is relatively low in order to raise it and for release of said gas from the receiving means back into the vessel means when the pressure level in the condensing and receiving means is relatively high in order to lower it.

2. The invention as defined in claim 1 in which the volume of the storage vessel means is sufficiently large to maintain the pressure of said non-condensable gas in said storage vessel means below a minimum pressure required for proper refrigerant flow from the high pressure side to the low pressure side, and above a rated low side pressure when the first and second valve means are selectively opened and closed.

3. The invention as defined in claim 1, and means responsive to the pressure in said receiving means for opening and closing said first and second valve means.

' 4. The invention as defined in claim 1, first and second means responsive to the pressure in said receiving means, means connecting said first pressure responsive means to said first valve means and means connecting said second pressure responsive means to said second valve means, whereby said first and second valve means are automatically operated in response to the pressure in said receiving means.

5. A compression refrigeration system having a high side and a low side,

a storage chamber for non-condensable gas, first and second fluid lines connecting said refrigeration system to said storage chamber,

first means responsive to a predetermined low pressure in said high side for opening said first fluid line and permitting entry of said non-condensable gas into said high side to raise pressure in said high side above such predetermined low pressure, said first pressure responsive means operative to close said first fluid line at a selected pressure in said high side above said predetermined low pressure,

second means responsive to a predetermined upper pressure in said high side for opening said second fluid line to relieve pressure and permit escape of non-condensable gas from said high said when said high side pressure is above said selected pressure, said second pressure responsive means operative to close said second fluid line at a pressure in said high side below said pressure at which said second fluid line is opened but above said selectedpressure.

6. The method of controlling the range of pressure level in the high side of a refrigeration system having a compressor and a low side, comprising providing an auxiliary housing for a non-condensable gas, continuously sensing the level of pressure in the high side, withdrawing non-condensable gas from the auxiliary housing into the low side, through the compressor and into the high side when the pressure level in the high side is below a predetermined level only to the extent necessary to. raise the pressure to a predetermined operating level, and withdrawing the non-condensable gas from the high side directly into the auxiliary housing in response to a level of pressure in the high side which is above a predetermined level.

IF i

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2951350 *Jun 23, 1958Sep 6, 1960Gen ElectricVariable capacity refrigeration
US3499298 *Apr 8, 1968Mar 10, 1970American Air Filter CoCondenser pressure control means
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4170998 *Sep 30, 1976Oct 16, 1979Chattanooga Pharmacal CompanyPortable cooling apparatus
US4246759 *Apr 25, 1977Jan 27, 1981Abg-Semca S.A.Method and apparatus for conditioning air
US4365482 *Aug 17, 1979Dec 28, 1982Sixten LanggardDevice at heating or cooling unit
US4420943 *May 10, 1982Dec 20, 1983Raytheon CompanyMethod and apparatus for refrigerator defrost
US4546616 *Feb 24, 1984Oct 15, 1985Carrier CorporationHeat pump charge optimizer
US4841739 *Jun 22, 1988Jun 27, 1989Sueddeutsche Kuehlerfabrik Julius Fr. Behr Bmgh. & Co. KgAutomotive air-conditioning system and apparatus
US5259204 *Jan 8, 1993Nov 9, 1993Mckeown DennisRefrigerant release prevention system
US5269151 *Apr 24, 1992Dec 14, 1993Heat Pipe Technology, Inc.Passive defrost system using waste heat
US5335511 *Sep 9, 1993Aug 9, 1994Mckeown DennisRefrigerant release prevention system
US5359863 *Jun 29, 1993Nov 1, 1994Conair CorporationRefrigerant conservation system
US5361592 *Mar 18, 1994Nov 8, 1994Conair CorporationRefrigerant conservation system
US5372013 *Jul 26, 1993Dec 13, 1994Billy Y. B. LauQuick cooling air conditioning system
US5379604 *Nov 19, 1993Jan 10, 1995Houston Industries IncorporatedEmergency refrigerant recovery activation system
US5477697 *Sep 2, 1994Dec 26, 1995Forma Scientific, Inc.Apparatus for limiting compressor discharge temperatures
US5586443 *Sep 20, 1995Dec 24, 1996Conair CorporationRefrigerant conservation system and method
US5784892 *Sep 9, 1996Jul 28, 1998Electric Power Research Institute, Inc.Refrigerant charge variation mechanism
US5937660 *Jan 17, 1998Aug 17, 1999Lau; Billy Ying BuiQuick cooling air conditioning system
US6101822 *Sep 1, 1999Aug 15, 2000Groves; EugeneConstant volume air conditioning/heat pump efficiency improvement apparatus
US6539735Dec 3, 2001Apr 1, 2003Thermo Forma Inc.Refrigerant expansion tank
US9151522 *Oct 23, 2012Oct 6, 2015Lg Electronics Inc.Air conditioner and control method thereof
US20130098072 *Oct 23, 2012Apr 25, 2013Bongsoo CHOIAir conditioner and control method thereof
WO1995003516A1 *Jul 22, 1994Feb 2, 1995Lau Billy YA quick cooling air conditioning system
WO1998049503A1 *Nov 12, 1997Nov 5, 1998Tyler Refrigeration CorporationRefrigeration system
Classifications
U.S. Classification62/85, 62/196.1, 62/174, 62/149
International ClassificationF25B49/02
Cooperative ClassificationF25B49/027, F25B2600/0261, F25B2400/0411, F25B2400/0409
European ClassificationF25B49/02D
Legal Events
DateCodeEventDescription
May 2, 1989ASAssignment
Owner name: CANADIAN IMPERIAL BANK OF COMMERCE
Free format text: SECURITY INTEREST;ASSIGNOR:YORK INTERNATIONAL CORPORATION;REEL/FRAME:005156/0705
Effective date: 19881215