330 results about "Heat rejection" patented technology

A refrigerant vapor compression system includes a refrigerant-to-refrigerant heat exchanger economizer and a flash tank disposed in series refrigerant flow relationship in the refrigerant circuit intermediate a refrigerant heat rejection heat exchanger and a refrigerant heat absorption heat exchanger. A primary expansion valve is interdisposed in the refrigerant circuit upstream of the refrigerant heat absorption heat exchanger and a secondary expansion valve is interdisposed in the refrigerant circuit upstream of the flash tank. The flash tank functions as a refrigerant charge storage reservoir wherein refrigerant expanded from a supercritical pressure to subcritical pressure separates into liquid and vapor phases. A refrigerant vapor bypass line is provided to return refrigerant vapor from the flash tank to the refrigerant circuit downstream of the refrigerant heat absorption heat exchanger. The primary expansion valve and a flow control valve interdisposed in the refrigerant vapor bypass provide refrigerant charge management.

A low pressure suction side refrigerant to liquid refrigerant heat exchanger, located in the refrigeration circuit in such a way that the sensor (and external equalizer tube, if applicable) is located downstream of the low pressure refrigerant outlet of the heat exchanger, provides for effectively eliminating both the superheat and flash gas loss regions of the evaporator which in turn increases the mass flow through the evaporator and increases the refrigerating capacity of the evaporator at very little increase in compressor power thereby providing for increased system efficiency for refrigerating or cooling purposes. On the heating side, heat rejection capacity of a heat pump is increased even more dramatically because of the heat reclaim of the flash gas loss heat, which provides for even greater efficiency increases for heating applications.

A refrigerant vapor compression system includes a flash tank disposed in the refrigerant circuit intermediate a refrigerant heat rejection heat exchanger and a refrigerant heat absorption heat exchanger. The flash tank has a shell defining an interior volume having an upper chamber, a lower chamber and a middle chamber. A first fluid passage establishes fluid communication between the middle chamber and the upper chamber and a second fluid passage establishing fluid communication between the middle chamber and the lower chamber. An inlet port opens to the middle chamber. A first outlet port opens to the upper chamber and a second outlet port opens to the lower chamber.

The invention provides a method of converting heat energy to a more usable form using a multi-component working fluid mixture that contains ammonia and water. The working fluid is operated in a thermodynamic cycle that includes liquid compression (30), vaporization (33), expansion through a turbine (34) and condensing (36). The multi-component fluid varies in temperature during phase change allowing for the use of counter-flow heat exchangers for the heater (33), cooler (36), recuperator and pre-heater (32). Significant recuperation is possible due to the temperature change during phase change. A pre-heater (32) can be applied to ensure only single-phase vapour exists within the heater. The invention can be used in conjunction with a biomass combustor or with waste flue gas from an existing industrial process. The coolant exits at a temperature sufficient to allow use in external heating applications or to minimize the size of external heat rejection equipment

An apparatus and method of cooling a plurality of electronic components in a housing using one or more fans cooperating with baffles or ducts for directing a stream of air sequentially to the components or heat exchangers for the components. Direction of the air stream to the components is based on predetermined cooling prioritization of the plurality of components.

A refrigerant vapor compression system includes a flash tank economizer defining a separation chamber is disposed in the refrigerant circuit intermediate a refrigerant heat rejection heat exchanger and a refrigerant heat absorption heat exchanger. A primary expansion valve is interdisposed in the refrigerant circuit in operative association with and upstream of the refrigerant heat absorption heat exchanger and a secondary expansion valve is interdisposed in the refrigerant circuit in operative association and upstream of the flash tank economizer. A refrigerant vapor injection line establishes refrigerant flow communication between an upper portion of the separation chamber and an intermediate pressure stage of the system's compression device and a suction pressure portion of the refrigerant circuit. A refrigerant liquid injection line establishes refrigerant flow communication between a lower portion of said separation chamber and an intermediate pressure stage of the compression device and a suction pressure portion of the refrigerant circuit.

A carbon dioxide refrigerant vapor compression system and method of operating that system are provided. The refrigerant vapor compression system includes a compression device, a flash tank receiver disposed in the refrigerant circuit intermediate a refrigerant heat rejection heat exchanger and a refrigerant heat absorption heat exchanger, and a compressor unload circuit including a refrigerant line establishing refrigerant flow communication between an intermediate pressure stage of the compression device and the refrigerant circuit at a location downstream of the refrigerant heat absorption heat exchanger and upstream of a suction inlet to the compression device, and a unload circuit flow control device disposed in said unload circuit refrigerant line. In response to at least one system operating parameter sensed by at least one sensor, the controller selectively positions the unload flow control device to maintain the refrigerant vapor compression system operating below a preselected high pressure limit.

A controller identifies a condition of a hazardous internal short by comparing patterns of series element voltages to the last known balance condition of the series elements. If the loaded or resting voltage of one or more contiguous series elements uniformly drop from the previously known condition by an amount consistent with an over-current condition, an over-current internal short circuit fault is registered. The desired response is to prevent the affected series elements from heating to a hazardous temperature by summoning the maximum heat rejection capability of the system until the short ceases and the affected elements cool, the cooling function is no longer able to operate due to low voltage, or the affected series string has drained all of its energy through the short. Also includes are responses that allow the battery pack to continue to power the cooling system even though it may enter an over-discharged state.

A chiller plant which produces chilled water for airconditioning, or an industrial process and which is comprised of chillers, cooling fluid pumps, and cooling towers with electrical motor drives uses a substantial amount of energy. A method that coordinates the operation of the cooling tower, cooling fluid pumps, and refrigeration machines so that the chiller plant operates at a higher overall efficiency thus reducing the power usage has been developed and is presented herein. The flow rate of the cooling fluid pumps are controlled to maintain a precise temperature difference across the refrigerant condenser. The cooling tower fans are controlled by comparing the cooling fluid temperature and the cooling fluid flow rate to selected design parameters. The heat rejection rate is measured for each chiller in the chiller plant and operating set points are established for each operating chiller to provide the optimum operation for best energy efficiency.

A refrigerating system comprises a compressor (1A, 1B, 1C), a heat rejection device (2), an expansion device (15), an evaporator (5A, 5B, 5C) and a receiver (4), capable of operating with the compressor discharge higher than the critical pressure of the refrigerant; where

• • the flow outlet from the heat rejection device is regulated by a pressure control valve (7),
  • the pressure downstream of the pressure control valve is regulated by a gas vent valve (8),
  • the refrigerant flow to the evaporator is further regulated by an automatic control device (41, 52, 14) at the inlet to the evaporator, and
  • the automatic control device being set to permit intermittent flow of liquid refrigerant to the receiver during normal operation of the system.

The refrigerant may be carbon dioxide, which may operate under transcritical pressures e.g. 80 to 120 bar absolute. The receiver acts as a trap for any liquid from the evaporator and ensures that the gas flow to the compressor suction is dry.

A controller identifies a condition of a hazardous internal short by comparing patterns of series element voltages to the last known balance condition of the series elements. If the loaded or resting voltage of one or more contiguous series elements uniformly drop from the previously known condition by an amount consistent with an over-current condition, an over-current internal short circuit fault is registered. The desired response is to prevent the affected series elements from heating to a hazardous temperature by summoning the maximum heat rejection capability of the system until the short ceases and the affected elements cool, the cooling function is no longer able to operate due to low voltage, or the affected series string has drained all of its energy through the short. Also includes are responses that allow the battery pack to continue to power the cooling system even though it may enter an over-discharged state.

A gas turbine engine having an oil cavity architecture and bearing placement which reduce heat rejection and oil system complexity by enclosing the reduction gearbox bearings and at least the shaft bearings supporting the high pressure shaft in the same oil cavity.

Methods and systems are provided for controlling and coordinating control of a post-catalyst exhaust throttle and an EGR valve to expedite catalyst heating. By closing both valves during an engine cold start, an elevated exhaust backpressure and increased heat rejection at an EGR cooler can be synergistically used to warm each of an engine and an exhaust catalyst. The valves may also be controlled to vary an amount of exhaust flowing through an exhaust venturi so as to meet engine vacuum needs while providing a desired amount of engine EGR.

A refrigerant system includes at least one compressor (54, 56) that compresses refrigerant and delivers it downstream to a heat rejection heat exchanger (26). The heat rejection heat exchanger is a microchannel heat exchanger. Refrigerant passes from the heat rejection heat exchanger downstream to an expansion device (60), from the expansion device through an evaporator (66), and from the evaporator back to the at least one compressor. A control (58) operates at least one compressor and the expansion device to reduce pressure spikes at transient conditions.

A refrigerant vapor compression system includes a compression device having at least a first compression stage and a second compression stage, a refrigerant heat rejection heat exchanger disposed downstream with respect to refrigerant flow of the second compression stage, and a refrigerant intercooler disposed intermediate the first compression stage and the second compression stage. The refrigerant intercooler is disposed downstream of the refrigerant heat rejection heat exchanger with respect to the flow of a secondary fluid. A second refrigerant heat rejection heat exchanger may be disposed downstream with respect to refrigerant flow of the aforesaid refrigerant heat rejection heat exchanger, and a second refrigerant intercooler may be disposed intermediate the first compression stage and the second compression stage and downstream with respect to refrigerant flow of the aforesaid refrigerant intercooler.

A system for producing liquefied and sub-cooled natural gas by means of a refrigeration assembly using a single phase gaseous refrigerant comprises at least two expanders; a compressor assembly; a heat exchanger assembly for heat absorption from natural gas; and a heat rejection assembly, in which the expanders are arranged in expander loops and the refrigerant to the respective expander is served in a compressed flow by means of the compressor assembly having compressors or compressor stages enabling adapted inlet and outlet pressures for the respective expander. According to the present the expanders and compressors assembly are assembled in two mechanically connected compressor and expander packages of which one is driven by a gas turbine and the other is driven by a steam turbine, the steam primarily being generated by exhaust gases from the gas turbine in a waste heat recovery unit, and in that the expanders and compressors assemblies are distributed between the two compressor and expander packages to optimize the steam utilization and to balance the power generated by the gas turbine and the steam turbine.

Modular living green wall systems are provided that supply water-cooled heat rejection for building cooling, power generation, industrial, chemical, and other processes that rely on heat rejection to the ambient environment for their efficient operation. Warm water from the process requiring heat rejection is circulated vertically through channels of porous media of the system and is cooled by evaporative and/or convective heat transfer to the ambient air that flows over and/or through the porous media across or counter to the water flow direction. Cool water leaving the system is piped to a heat exchanger of the process to provide the requisite cooling and is returned warm to the modular green wall system to complete the circulation loop. Modular living green wall systems may be assembled using plant modules and water treatment modules that are nested together to form continuous porous vertical water flow channels and a water recirculation system. The plant modules may consist of an inner porous media layer and an exposed porous substrate layer attached to each other and a stackable module housing. The water treatment module may be housed in a compatible stackable housing containing horizontal layers of filtration media. These modules are stacked in an interlocking manner and may be attached to an existing building support structure or alternatively be used to form a free standing living green wall.