Thermo King Corporation

Westinghouse Electric Corporation

Lars Ivan Sjoholm

Peter W Freund

Lee J Erickson

Sung L Kwon

David H Taylor

Panayu Robert Srichai

Eric Steven Mlsna

Joseph Robert Kaiser

David John Dykes

Jeffrey Bryan Gronneberg

P Robert Srichai

Joseph Edward LaBossiere

Lowell B Naley

Casey Briscoe

Santiago Martinez Ballester

Dean W Osterman

Young Chan Ma

Gregory Gordon Anderson

Dean William Osterman

Youngchan Ma

A climate control system includes a compressor which includes a compressor housing, a compressor element provided in the compressor housing, a lubricant circuit, and an auxiliary sump. The lubricant circuit includes a lubricant sump provided in the compressor housing. The auxiliary sump is in fluid communication with the lubricant sump. A method for maintaining lubrication supply for a compressor of a climate control system includes transferring lubricant from the auxiliary sump to the lubricant sump of the compressor when a height of the lubricant in the auxiliary sump is greater than a height in the lubricant sump and returning the lubricant from the lubricant sump to the auxiliary sump when a height of the lubricant in the lubricant sump is higher than a height of a predetermined minimum level in the lubricant sump. The lubricant in the auxiliary sump and lubricant sump are equalized by gravity.

Methods and systems for lubricating a transport climate control system having an auxiliary sump

A transport climate control system to cost-effectively maintain an ultra-low temperature over an extended period of time is provided. The transport climate control system includes a primary climate control system and a secondary climate control system. The primary climate control system includes a first compressor, a first condenser, a first expander, and a main evaporator that is configured to thermally communicate with a climate controlled space. The secondary climate control system includes an ultra-low temperature phase changing medium packaged inside or outside of an enclosure for a cargo. The secondary climate control system is configured to thermally communicate with the climate controlled space, the primary climate control system, and the cargo to provide additional or backup climate control capacity at the ultra-low temperature.

Methods and systems for maintaining cargo at an ultra-low temperature over an extended period of time

A climate control circuit for a transport climate control system is provided. The circuit includes a compressor, a plurality of evaporators, a suction flow control device, and a controller. The suction flow control device is downstream of the plurality of evaporators and directs the working fluid from each of the evaporators to one of a main suction port and an auxiliary port of the compressor. The controller determines whether each of the evaporators is operating in a fresh temperature range or in a frozen temperature range. For each of the evaporators operating in the fresh temperature range, the controller instructs the suction flow control device to direct the working fluid from the corresponding evaporator to the auxiliary suction port. For each of the plurality of evaporators operating in the frozen temperature range, the controller instructs the suction flow control device to direct the working fluid to the main suction port.

System and method of energy efficient operation of a transport climate control system

A method for providing supplemental flow control of working fluid through a transport climate control circuit during a start-stop cooling operation mode is provided. The method includes closing a main liquid suction solenoid valve disposed between a condenser and an evaporator of the transport climate control circuit when the compressor is OFF. The method also includes monitoring a climate controlled space temperature within a climate controlled space. When the climate controlled space temperature is greater than or equal to a setpoint temperature, the method includes turning a compressor ON, and opening the main liquid suction solenoid valve when a suction pressure at the suction port of the compressor is less than or equal to a predetermined suction pressure threshold. When the climate controlled space temperature is less than or equal to the setpoint temperature, the method includes turning the compressor OFF, and closing the main liquid suction solenoid valve.

Methods and systems for supplemental flow control of working fluid through a climate control circuit

A refrigeration system having a cooling circuit, a heating circuit, a pressurizing receiver tank circuit, a pilot circuit and a liquid injection circuit wherein the hot gas line includes a solenoid valve that connects an outlet of a compressor to an outlet of a receiver tank, and wherein the liquid injection circuit includes a liquid injection solenoid that connects the outlet of the receiver tank to an outlet of an economizer.

Method of operating a refrigeration system in a null cycle

Economizer combined with a heat of compression system

A refrigerant compressor assembly for a refrigeration circuit controls the temperature within a temperature controlled space. The refrigerant compressor assembly includes a first unloading valve, a first valve actuator, and a first valve control system that adjusts the first valve actuator via a pulse-width-modulated signal, a second unloading valve, a second valve actuator, and a second valve control system that adjusts the second valve actuator via a pulse-width-modulated signal. The refrigerant compressor assembly also includes a third unloading valve. The first valve actuator is coupled to the first and third unloading valves and controlled by the first valve control system. The unloading valves selectively allow or resist fluid flow from higher to lower pressure areas within the refrigerant compressor assembly.

Temperature control through pulse width modulation

A method for controlling at least one electronic expansion valve coupled to an economizer in a refrigeration system in order to dynamically control the refrigeration system operating conditions and in order to accommodate more than one set of operating conditions. The system can also be used to control the capacity of the system. More specifically, the method can include determining the required capacity of the system and adjusting the flow of refrigerant through the electronic expansion valve to adjust the actual capacity of the system toward the required capacity of the system. In another aspect of the invention, the system is operated to maintain the power of the system below a threshold value (e.g., below a max rated horsepower). This method includes determining the power required to operate the compressor based on the measurement of system parameters; comparing the power required to a threshold value; and adjusting the flow of refrigerant through the electronic expansion valve in order to keep the power required below the threshold value. In yet another aspect of the invention, the system is operated in order to prevent overheating of the compressor. More specifically, the flow of refrigerant from the heat exchanger to the compressor can be adjusted so that some amount of liquid refrigerant is provided to quench the compressor.

Refrigeration unit apparatus and method

A screw compressor includes a suction end, a discharge end, first and second rotors mounted for rotation between the suction end and the discharge end, and a discharge housing at the discharge end. The discharge housing surrounds a portion of the first and second rotors and includes an end surface. The compressor further includes a first axial bearing supporting the first rotor, and a wear-preventing member sandwiched between the end surface of the discharge housing and the first axial bearing such that no portion of the first axial bearing contacts the end surface. The screw compressor further includes a first radial bearing in the discharge housing for supporting the first rotor. The wear-preventing member includes a face abutting the end surface of the discharge housing and abutting at least a portion of the first radial bearing to retain the first radial bearing in the discharge housing.

Wear-preventing and positioning device for a screw compressor

A screw compressor having an unloader valve with a movable valve member, the unloader valve being capable of indicating when the valve member is installed incorrectly. The valve member is manufactured such that if it is installed incorrectly it provides a leakage path sufficiently large to be detected during full load testing of the compressor. When the screw compressor fails the load test, the compressor is partially disassembled, and the valve is reinstalled in the proper orientation and the compressor is re-tested. The valve member leakage path is provided while maintaining low costs for production and assembly of the compressor.

Axial unloading lift valve for a compressor and method of making the same

A compressor and oil separator assembly for compressing a fluid includes a suction end, a discharge end, and first and second rotors rotatably mounted between the suction and discharge ends. A discharge line communicates with the discharge end, and an oil separator communicates with the discharge line. An oil sump communicates with the oil separator and an oil supply line communicates between the oil sump and the rotors. A bleed line selectively communicates between the discharge line and the oil supply line for equalizing a pressure differential between the suction end and the discharge end without causing substantial backward rotation of the rotors or displacement of oil to the rotors through the oil supply line. Preferably, the assembly further includes a valve that defines a portion of the discharge line and is also coupled to the bleed line.

Valve arrangement for a compressor

A transport refrigeration system for heating and cooling a conditioned space is provided that includes an improved, combined heat exchanger and economizer for increasing the efficiency of the refrigeration cycle. The system includes a refrigerant compressor driven by an internal combustion engine that includes suction and discharge ports, and an intermediate pressure port; a refrigeration circuit including a heating coil and evaporator assembly thermally connected to the conditioned space, and a mode valve for selectively routing the refrigerant through either the heating coil or the evaporator assembly via a condenser to heat or cool the conditioned space, respectively. The combined heat exchanger and economizer includes a tube connected to the intermediate suction port of the compressor, a shell for conducting refrigerant to the evaporator assembly depending upon the position of the mode valve, and a jacket for circulating engine coolant. During the heating mode of the system, a volume of refrigerant is maintained in the shell of the combined heat exchanger and economizer to act as a thermal buffer for heat transferred between engine coolant circulating through the jacket, and refrigerant flowing through the tube of the device.

Refrigeration system and method utilizing combined economizer and engine

A refrigeration system of the type having an economizer cycle is provided with a null cycle, in addition to heating and cooling cycles, without shutting a compressor prime mover down, to preserve air flow in a conditioned space. First, second and third controllable valves respectively: (1) select main and auxiliary condensers, (2) open and close a liquid line, and (3) open and close a line which provides a warm liquid to an economizer heat exchanger. The valves are controlled in at least one predetermined open/close pattern during a null cycle, and preferably in a plurality of selectable predetermined open/close patterns, to provide a null cycle at any instant which substantially matches the net heat gain or loss taking place in the conditioned space. Thus, the temperature of the served space will be more apt to remain in a null temperature range close to set point, providing smoother and more accurate control over the temperature of the conditioned space for longer shelf life of perishables stored therein. The system achieves the latter by controlling cooling circulation in the compressor oil cooler.

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Burnsville, MN, United States of America

Lars Ivan Sjoholm