Abstract:
The present invention is directed to heat exchangers for process tools and, in particular, to semiconductor process tools incorporating heat exchangers. In one embodiment, the present invention is directed to a semiconductor process tool heat exchange system. The system includes a heat exchange system and a semiconductor process tool comprising an inlet and an outlet defining a flow path. The heat exchange system includes a compressor fluidly connected to the outlet, a condenser fluidly connected to the compressor and to the inlet, an expander positioned between the condenser and the outlet, and a heat exchange fluid. Examples of process tools suitable for use in this system include cathodes, cold plates, thermal chucks, and the like. In another embodiment, the present invention is directed to a method of exchanging heat in a semiconductor process tool. The method includes supplying a condensed heat exchange fluid to the semiconductor process tool and expanding the condensed heat exchange fluid to an expanded heat exchange fluid within the semiconductor process tool. In another embodiment, the method includes supplying a compressed heat exchange fluid to the semiconductor process tool and condensing the compressed heat exchange fluid to a condensed heat exchange fluid within the semiconductor process tool. Thus, depending on the embodiment, the method is suitable for both cooling and heating a semiconductor process tool.
Abstract:
A variable restrict valve is disposed at the upstream side of a refrigerant flow, a fixed restrictor is disposed at the downstream side of the variable restrict valve, an intermediate space is provided between the variable restrict valve and the fixed restrictor, a passage sectional area of the intermediate space is set to be larger than the fixed restrictor and passage length L of the intermediate space is set to be larger than a predetermined length required when the flow of refrigerant injected from the variable restrict valve expands more than the passage sectional area of the fixed restrictor.
Abstract:
A flash tank employing valves for use in transcritical cycles of a vapor compression system to increase the efficiency and/or capacity of the system. Carbon dioxide is preferably used as the refrigerant. The high pressure of the system (gas cooler pressure) is regulated by controlling the amount of charge in the flash tank by actuating valves positioned on the expansion devices located at the entry and exit of the flash tank. If the pressure in the gas cooler is too high or too low, the valves can be adjusted to either store charge in or release charge from the flash tank. By regulating the amount of charge in the flash tank, the high pressure of the system can be controlled to achieve optimal efficiency and/or capacity.
Abstract:
A supercritical vapor compression cycle is provided having an improved cooling efficiency in the gas cooler, capable of automatically controlling the necessary circulating coolant quantity by adjusting the high side pressure. The supercritical vapor compression cycle comprises a compressor 1, a gas cooler (radiator) 2, a diaphragm resistor 4a, and evaporators, all of which is connected serially by a pipe 1 so as to form a closed circuit operated at the supercritical pressure at the high side, and further comprises a pressure control valve for controlling the pressure at the outlet of the gas cooler 2 so as to obtain the maximum performance factor of the supercritical vapor compression cycle, a reservoir 5, through which the pipe 6 from the outlet of the evaporator penetrates, for storing the liquid coolant 5a, and a communication pipe 5b communicating the bottom of the reservoir 5 with the pipe 6 connecting the pressure control valve with the diaphragm resistor.
Abstract:
A refrigerating system, using CO.sub.2 as a refrigerant, for an air conditioner for an automobile. A pressure at the outlet of the heat emitter 2 is controlled to a target value in accordance with the temperature of the refrigerant at the outlet of the heat emitter for obtaining an operation of the refrigerating system along the optimum control line .eta..sub.max. A pressure reducer 4 and a cooler 5 are provided on a branched passageway 28 branched from a refrigerant recirculating passageway 27 for injection. The cooler 5 is for obtaining a heat exchange between a flow of the refrigerant on the branched passageway 28 after being cooled by the pressure reducer and a flow of the refrigerant on the main passageway 27, thereby cooling the refrigerant directed to the evaporator. In a second aspect of the invention, a means is provided for increasing a target value of the pressure at the pressure reducer when a thermal load of the refrigerating system is high. In a third aspect, a series of pressure reducers are arranged on the main recirculating passageway. The second stage pressure reducer is controlled so as to obtain a desired value of degree of super heating at the inlet of the compressor.
Abstract:
An air-conditioning apparatus comprises at least one variable-capability compressor which is contained in a casing together with a lubricating oil, and at least one fixed-capability compressor which is also contained in a casing together with a lubricating oil. The capability of the variable-capability compressor and the number of fixed-capability compressors to be driven, are controlled in accordance with the sum of the air-conditioning loads of a plurality of indoor units. The casings are connected together by means of an oil-balancing pipe. The air-conditioning apparatus further comprises a plurality of oil-balancing devices. These oil-balancing devices are driven on the basis of different control patterns and distribute the lubricating oil between the casings by way of the oil-balancing pipe. The oil-balancing devices are selectively driven in accordance with both the control of the capability of the variable-capability compressor and the control of the number of fixed capability compressors to be driven.
Abstract:
An air conditioning system in which a subcooling valve is located in the liquid line fitting upstream from the evaporator creating a pressure drop ahead of the capillary tube to effect liquid subcooling of refrigerant leaving the condenser, thereby resulting in higher cooling capacity and efficiency.