Carrier Corporation

Electric Power Research Institute Incorporated

Other

Lowell E Paige

Chester D Ripka

Kevin F Dudley

Kevin Bryant Dunshee

Richard J Duell

Wayne B Cavanaugh

David A Condit

Warren R Clough

Thomas E Drago

Roger J Voorhis

H Harvey Michels

William A Faris

John Attanasio

A method for testing a non-hydrocarbon refrigerant, such as CFC-12 or HFC-134a, in a closed system for hydrocarbons, HCFC-22 refrigerant and ammonia is provided wherein a sample of the non-hydrocarbon refrigerant is withdrawn from the closed system, the pressure of the sample is measured and a metered portion of the sample is passed through a test apparatus (20) including a testing tube (30), a testing tube holder (40) for supporting the testing tube (30) and outfitted with a vent (48) to the atmosphere, and a pressure gauge (70) for indicating the pressure of the sample withdrawn. A medium (38) for indicating the presence of hydrocarbons in the sample flow passing through the testing tube is deposited on a surface disposed in the testing tube. The presence of undesired HCFC-22 refrigerant in the CFC-12 or HFC-134a is indicated by a higher pressure reading on the pressure gauge (70). Finally, the presence of ammonia is sensed by its characteristic pungent odor as the refrigerant sample flow is vented to the atmosphere.

Method and apparatus for testing a non-hydrocarbon refrigerant

Refrigerant recovery unit

A refrigeration system having a refrigerant compressor which has a refrigerant purity sampling circuit in parallel fluid flow communication therewith. The purity sampling circuit includes a refrigerant purity tube holder in which a refrigerant purity tube may be removably supported to thereby cause a flow of refrigerant therethrough during a purity sampling test due to the pressure differential across the compressor. The refrigerant purity sampling holder is adapted to receive an empty open ended test tube therein. The empty tube is left in the holder at all times, except when it is desired to perform a purity sampling test, in which case the empty open tube is removed and an active purity sampling tube is inserted therein. The system is further provided with the capability of purging the empty open ended tube and the refrigerant purity sampling circuit prior to the installation of an active tube.

Method of testing the purity of refrigerant flowing through a

A refrigerant recovery system is operated to withdraw compressible refrigerant from a refrigeration system by first withdrawing liquid refrigerant from the system being serviced through a suitable conduit and delivering the withdrawn refrigerant directly to a refrigerant storage means. In the refrigerant storage means at least a portion of the refrigerant so withdrawn exists in gaseous form and a portion of this is withdrawn from the storage means and passed serially through a compressor, a condenser, and a refrigerant expansion device before being delivered back to the refrigerant storage means where is evaporates and absorbs heat from the refrigerant within the storage means thereby cooling the storage means and lowering the pressure therein to thereby increase the withdrawal of the liquid refrigerant from the refrigeration system through the conduit. The system controlled parameters including temperature of the refrigerant and the storage means, and compressor suction and discharge pressure are sensed. A detectable change in the value of these system control parameters occur at a time which may be correlated at a time at which the state of the refrigerant being withdrawn from the refrigeration system changes from liquid to vapor. This information is used to shift the system from a liquid recovery mode of operation to a vapor recovery mode.

Method and apparatus for recovering and purifying refrigerant including

A system for recovering compressible refrigerant from a refrigeration system, of the type having a compressor for lowering the pressure in the refrigeration system to effect the withdrawal of the refrigerant therefrom, and directing the refrigerant to a storage cylinder. The system is operable in a storage cylinder cooling mode of operation wherein the temperature and pressure of the refrigerant withdrawn from the system and stored in the cylinder is lowered. A control system for limiting the pressure ratio across the compressor during operation of the recovery system is provided. The control system includes first means for determining the suction pressure of the compressor and for terminating operation of the recovery system when a desired termination pressure is reached. A second means is provided for determining suction pressure of the compressor, and, for interrupting power to the compressor, and generating a signal perceivable to the user of the recovery system when a predetermined suction pressure greater than the termination pressure is reached. Means are provided for determining the discharge pressure of the compressor, and, for selectively placing the first means for determining suction pressure in the circuit of the control system when the discharge pressure is less than a predetermined value, or, for placing the second means for determining suction pressure in the control system when the discharge pressure equals or exceeds the predetermined value.

Control system for compressor protection in a manually operated

Apparatus for recovering compressible refrigerant from a refrigeration system, purifying the recovered refrigerant, and testing the purity of the recovered purified refrigerant which includes a compressor, a condenser, a refrigerant storage means and a refrigerant purification means all connected in serial fluid communication. Means are provided for operably supporting a refrigerant purity sampling system in parallel fluid flow relationship with the compressor. The system is adapted to operate in a refrigerant recovery mode wherein refrigerant is withdrawn from a refrigeration system being serviced. This system is also capable of operating in a refrigerant purification mode wherein the refrigerant withdrawn from the refrigeration system is continually circulated through the circuit to provide multiple passes through the purification system. And a further refrigerant purity test mode of operation is provided wherein refrigerant from the storage cylinder is passed directly to a refrigerant purity sampling tube. This mode passes the refrigerant purifying means to thereby assure that the refrigerant being tested for purity is representative of the refrigerant stored in the storage container.

Apparatus for sampling the purity of refrigerant in the storage

A refrigerant recovery device for recovering compressible refrigerant from refrigeration system. The system includes in serial fluid communication, a compressor, a condensor, and a means for storing refrigerant. An expansion device is provided in the fluid line interconnecting the condensor and the storage means. A four way valve is provided which has one port interconnected with the refrigeration system being serviced, another port interconnected with the suction side of the compressor and two additional ports in fluid communication with the means for storing refrigerant. The four way valve may be actuated to recover liquid refrigerant from the refrigeration system being serviced by establishing a first path from the system being serviced directly to the means for storing refrigerant. The four way valve establishes a second path from the means for storing refrigerant, through the four way valve to the compressor, the condensor, and, through the expansion device where high pressure gaseous refrigerant is expanded and delivered to the storage cylinder to thereby cool the cylinder. The four way valve may be actuated to another position wherein the refrigeration system being serviced is in direct fluid communication with the suction port of the compressor to thereby directly recover refrigerant in vapor state from the refrigeration system.

Manually operated refrigerant recovery apparatus

A method and apparatus for sampling the purity of refrigerant flowing through a refrigeration system is provided. A refrigerant sampling chamber is operably connected and parralel fluid flow communication with a compressor of the refrigeration system. Operation of the compressor to establish the flow of refrigerant through the system results in withdrawal of a quantity of refrigerant from the high pressure side of the system. The withdrawn refrigerant passes through the refrigerant sampling chamber and a refrigerant quality testing tube contained therein. Following passage through the test chamber the withdrawn refrigerant is returned to the low pressure side of the refrigeration system.

Apparatus for sampling the purity of refrigerant flowing through a

A method and apparatus for recovering compressible refrigerant from a refrigeration system and delivering the recovered refrigerant to a refrigerant storage means. The recovery method includes the steps of withdrawing refrigerant from a refrigeration system being serviced and compressing the withdrawn refrigerant in a compressor to form a high pressure gaseous refrigerant. The high pressure gaseous refrigerant is delivered to a condenser where it is condensed to form liquid refrigerant. The liquid refrigerant from the condenser is delivered to the refrigerant storage means. Means are provided for stopping the withdrawal of refrigerant from the refrigeration system being serviced when a predetermined event occurs. When this occurs, the system begins to withdraw stored refrigerant from the storage means. The refrigerant withdrawn from the storage means is then compressed in the same compressor which was used to compress refrigerant withdrawn from the refrigeration system. This refrigerant is then condensed to form liquid refrigerant which is delivered directly back to the storage means to thereby pre-cool the storage means and the refrigerant contained therein. This pre-cooling cycle is performed for a predetermined time period. After the predetermined time period, the condensed refrigerant withdrawn from the storage means is caused to pass through an expansion means prior to delivering it back to the storage means to thereby cool the storage means.

Method and apparatus for compressor protection in a refrigerant recovery

A method and apparatus for recovering compressible refrigerant from a refrigeration system and delivering the recovered refrigerant to a refrigerant storage container. Means are provided for determining the type of refrigerant being recovered and for determining the ambient temperature. The recovery method includes the steps of withdrawing refrigerant from a refrigeration system being serviced and compressing the withdrawn refrigerant in a compresser to form a high pressure gas. A high pressure gaseous refrigerant is delivered to a condenser where it is condensed to form liquid refrigerant. The liquid refrigerant from the condenser is delivered to the refrigerant storage means. Means are provided for stopping the withdrawal of refrigerant from the refrigeration system being serviced when a predetermined event occurs. At that point, the system begins to withdraw stored refrigerant from the storage container. The refrigerant withdrawn from the storage container is then compressed in the same compresser which was used to compress refrigerant withdrawn from the refrigeration system. This refrigerant is then condensed and passed through an expansion device. If the refrigerant is not a higher pressure refrigerant, such as R-22 or R-502 it is passed through an expansion device having a predetermined effective refrigerant metering capability. If the refrigerant is a higher pressure refrigerant, such as R-22 or R-502, and the ambient temperature is greater than a predetermined value, it is passed through a flow control valve having an effective refrigerant metering capability which is between 5 to 20 times larger than the predetermined effective refrigerant metering capability of the expansion device.

Method and apparatus for recovering refrigerant

A method and apparatus for recovering and purifying refrigerant contained in a refrigeration system has a first mode of operation wherein refrigerant is withdrawn from the system being serviced, compressed, condensed and delivered in liquid form to a refrigerant storage means. The pressure ratio across the recovery compressor is monitored, and, when the pressure ratio exceeds a value above which the compressor may be adversely affected withdrawal of the refrigerant from the refrigeration system is terminated. The system is then operated in a closed, cooling mode wherein refrigerant recovered from the system and stored in the storage means is withdrawn therefrom by the compressor, compressed condensed, and expanded and returned to the storage means to thereby lower the temperature and pressure of the storage means and the refrigerant contained therein. Means for purifying the withdrawn refrigerant are located upstream from the compressor suction port so that refrigerant purification takes place during all modes of operation. When the temperature in the refrigerant storage cylinder falls to a predetermined level the system is returned to the recovery mode. During the second recovery cycle, because of the substantially lower temperature in the recovery system, the refrigerant storage cylinder effectively serves as a condenser.

Method and apparatus for recovering and purifying refrigerant

In an integrated heat pump and water heating system with a variable speed compressor drive, a variable speed indoor fan, and an expansion valve with a variable duty cycle the indoor fan speed is controlled as a function of a space heating load, and the compressor speed is controlled as a function of outdoor temperature and space heating load.

Control of space heating and water heating using variable speed heat pump

An integrated heat pump and hot water system of the type having a variable speed compressor is controlled during a water heating mode, in which outdoor air serves as the heat source. The controlling is carried out on the basis of a field of outside temperature and water temperature. The compressor speed is controlled based on the outdoor air temperature, and the compressor is run at a maximum speed between a minimum outdoor temperature and a low temperature somewhat above the minimum, at minimum speed for outdoor air temperature between a maximum temperature and a high temperature below the maximum temperature, and at a speed that depends linearly on outdoor temperature for intermediate outdoor temperatures. There is a permissible temperature field or envelope bounded by the minimum and maximum outdoor temperatures, by minimum and maximum water temperatures, and by an efficiency floor and a torque limit ceiling.

Control of outdoor air source water heating using variable-speed heat

An integrated air conditioning and water heating system provides cooling of a comfort zone, as required, as well as water heating. A variable speed compressor delivers compressed refrigerant first to a water heat exchanger and then to an outdoor condenser coil. From there the refrigerant cycles through an indoor evaporator coil back to the compressor. When the demand for water heating is above a predetermined amount and the cooling load is below a predetermined cooling load threshold, a full condensing mode is selected in which most of the heat from the comfort zone is used for water heating. If the cooling demand is high or if the water heating demand is low, a desuperheating mode is selected in which most of the heat is transferred to the outdoor air. The outdoor coil temperature is monitored and if it is above a safe limit, the desuperheating mode is selected. In the full condensing mode the outdoor fan is held off. In the desuperheating mode, the outdoor fan is energized.

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Pennellville, NY, United States of America

Lowell E Paige