American Standard Inc.

American Standard International Inc.

Electric Power Research Institute Incorporated

The Trane Company

Paul R Glamm

David H Eber

Dwayne L Johnson

Walter Earhart, Jr

John F Klouda

Brian J Kiel

Dale A Hulst

Lee L Sibik

Daniel C Leaver

Floyd C Hayes

Merle A Renaud

James C Wendschlag

A refrigeration system with a high percentage of fresh air. The system comprises a supply air duct; an indoor heat exchange coil operably positioned in the supply air duct; a reheat heat exchange coil operably positioned in the supply air duct; an outdoor heat exchange coil; at least one compressor; and an expansion device. The system also comprises refrigeration system tubing connected to and serially arranging the compressor, the outdoor heat exchange coil, the expansion device and the indoor coil into a refrigeration circuit; and reheat tubing connecting the reheat coil to the refrigeration tubing so as to arrange the reheat coil in a parallel circuited arrangement with the outdoor heat exchange coil and in a series circuited arrangement with the compressor, the expansion device and the indoor heat exchange coil. The system further comprises a subcooler located between and operably connected to the indoor heat exchange coil and the parallel circuited arrangement; and a control valve in the reheat tubing operable to control refrigerant flow through the reheat coil.

Refrigeration circuit with reheat coil

A method of controlling the capacity of a chiller system, the chiller system including a circularly linked compressor, condenser, expansion device, and evaporator. The method comprises the steps of: measuring a first chiller system parameter; determining a first parameter error as a function of the difference between the first parameter and a first setpoint; measuring a second chiller system parameter; determining a second parameter error as a function of the difference between the second parameter and a second setpoint; providing a first mode of capacity control where the compressor is modulated in response to the first parameter error and the expansion valve is modulated in response to the second parameter error; and providing a second mode of capacity control where the compressor is maintained at a minimum capacity and the expansion valve is modulated in response to the first parameter error.

Evaporator water temperature control for a chiller system

An electrically actuated valve for incremental fluid flow rate control is disclosed. The valve is comprised of a valve body having an interior with a planar outlet surface against which a rectilinear valve element is slidingly operated. The valve body includes an inlet orifice and an outlet orifice in the planar outlet surface for fluid flow through the valve body. The valve element has an orifice therethrough controlling flow through the outlet orifice in accordance with the position of the valve element, which is linearly actuated by a rotary stepper motor.

Incremental electrically actuated valve

A refrigeration system has multiple compressors in a parallel arrangement. The pressures in the shells of operating compressors are maintained equal by the controlled delivery of suction gas and entrained oil to the shells of individual operating compressors in quantities which maintain the pressures therein equal. A valve, directly responsive to compressor shell pressures, occludes the flow of suction gas to the shell of an operating compressor in which the pressure is greater than that found in the shell of another operating compressor so as to equalize the pressures in the compressor shells. The equalizing valve arrangement directs and apportions essentially the entire amount of suction gas to the shells of operating compressors while cutting off the flow of suction gas into the shells of non-operating compressors. By managing the flow of suction gas so as to maintain shell pressures equal in operating compressors, equal amounts of entrained oil are directed to the shells of the operating compressors so as to ensure that no operating compressor becomes starved for oil.

Oil management in a parallel compressor arrangement

An air conditioning system and method of operation for reducing cyclic losses due to non-steady state operation at the start of operating cycles are disclosed. A bi-flow expansion valve assembly is provided in the refrigerant line between the heat exchangers, and the valve assembly can meter refrigerant flow between the heat exchangers or can permit substantially unrestricted flow therethrough. At the start of a cycle, the valve assembly is adjusted to allow refrigerant to flood between the heat exchangers, thereby correcting mislocation of refrigerant caused by the migration of refrigerant to the evaporator during the off-cycle, or caused when heat exchanger functions are switched, as, for example, during a defrost cycle of a heat pump.

Air conditioning system and method of operation

A heat pump refrigeration circuit utilizes an indoor heat exchange unit, an outdoor heat exchange unit and a refrigerant-liquid heat exchange unit all connected serially to accomplish space heating, space cooling, liquid heating or simultaneous space cooling and liquid heating. A refrigerant charge reservoir is selectively incorporated into the circuit to control the refrigerant charge in the two liquid heating modes of operation by removing excess liquid refrigerant from the circuit. In the two non-liquid heating modes of operation the reservoir is isolated from all but the suction port of the compressor within the circuit. Liquid refrigerant previously deposited in the reservoir during a liquid heating mode of operation is vaporized and returned to the circuit for use in the selected non-liquid heating mode of operation. Refrigerant charge control is thereby maintained in all modes of operation without the necessity of evacuating an inactive heat exchanger.

Heat pump refrigeration circuit with liquid heating capability

A system is disclosed for the transfer of heat from an ambient heat sink of variable temperature to a conditioned space, said system being operable in a first mode when the temperature of the heat sink is at a relatively high level, and in a second mode when its temperature is at a relatively low level. The system includes a first refrigerant circuit which is operable in said first mode as a heat pump of the vapor compression type to absorb heat from the ambient heat sink and transfer same to the conditioned space. A second refrigerant circuit is provided which is operable in the second mode, when the temperature of the ambient heat sink is at a relatively low level, to absorb heat from the ambient heat sink and transfer same to the first refrigerant circuit, which then transfers the heat to the conditioned space. Thus, in second mode operation, the first and second refrigerant circuits operate in a 'cascade' relationship. Suitable control means are disclosed for effecting operation of the system as described above, and, in addition, a suitable method of operation for such a system is disclosed.

Growing community of inventors

La Crosse, WI, United States of America

Paul R Glamm