Abstract: In a liquid cooling system for a printed circuit board on which integrated circuit packages are mounted, heat sinks are secured respectively to the packages in heat transfer contact therewith. Nozzles are provided in positions corresponding to the heat sinks. A housing is tightly sealed to the printed circuit board to enclose the packages, heat sinks and nozzles in a cooling chamber. A feed pump pressurizes working liquid cooled by a heat exchanger and supplies the pressurized liquid to the nozzles for ejecting liquid droplets to the heat sinks. A liquid suction pump is connected to an outlet of the housing for draining liquid coolant to the heat exchanger and a vapor suction pump is connected to a second outlet of the housing for sucking vaporized coolant to the heat exchanger. The cooling chamber is maintained at a sub-atmospheric pressure to promote nucleate boiling of the working fluid.

Abstract: A liquid coolant circulation control system that minimizes the requisite feed pressure and keeps the flow rate of a liquid coolant constant includes a casing accommodating electronic circuits to be immersed in and cooled by a liquid coolant, a feed pump for feeding the liquid coolant to the casing, and a collecting pump for collecting the liquid coolant from the casing. A first measuring meter, interposed between the feed pump and the casing, measures a flow rate and/or a pressure of the liquid coolant flowing into the casing. A second measuring meter, interposed between the casing and the collecting pump, measures a flow rate and/or a pressure of the liquid coolant flowing out of the casing. A determining section calculates a difference or differences between the two flow rates and/or pressures. The determining section sends this information to a control section. The control section controls the output of one or both pumps, so that the difference or differences remain at a predetermined value.

Abstract: A liquid coolant circulation control system that minimizes the requisite feed pressure and keeps the flow rate of a liquid coolant constant includes a casing accommodating electronic circuits to be immersed in and cooled by a liquid coolant, a feed pump for feeding the liquid coolant to the casing, and a collecting pump for collecting the liquid coolant from the casing. A first measuring meter, interposed between the feed pump and the casing, measures a flow rate and/or a pressure of the liquid coolant flowing into the casing. A second measuring meter, interposed between the casing and the collecting pump, measures a flow rate and/or a pressure of the liquid coolant flowing out of the casing. A determining section calculates a difference or differences between the two flow rates and/or pressures. The determining section sends this information to a control section. The control section controls the output of one or both pumps, so that the difference or differences remain at a predetermined value.

Abstract: A cooling abnormality detection system for external electronic equipment includes a protection unit. The protection unit includes two temperature sensors arranged in each piece of external electrical equipment to be monitored, in order to measure the temperature of each. A temperature difference measuring means receives the measured temperature from each piece of equipment and outputs a sensor failure signal when the absolute value of difference between the temperatures measured by the two temperature sensors exceeds a first predetermined value. An abnormal temperature signal is output from the temperature difference measuring means when the two measured temperatures both exceed a second value. The sensor failure signal is transmitted to the electronic equipment, while generation of the abnormal temperature alarm interrupts the power supply to the electronic equipment.

Abstract: An excess heat abnormality detection and alarm system for external electronic equipment includes a protection unit containing a timer for counting a predetermined period of time and outputting a time output signal, a temperature measuring means for causing temperature sensors to measure the temperatures of the electronic components, a first and second abnormal temperature discriminating means, the first abnormal temperature discriminating means being operated for a predetermined period of time set in the timer means. The first abnormal temperature discriminating means identifies or discriminates one of the temperatures measured by the temperature measuring means as an abnormal temperature. A second abnormal temperature discriminating means operated after a predetermined period of time set in the timer means distinguishes between the two temperatures measured by the temperature measuring means.

Abstract: According to this invention, a liquid coolant circulating system includes a cooling tank, a discharge pump, a recovery pump, a heat exchanger, a detector, and a controller. The cooling tank is filled with a liquid coolant for immersing an object to be cooled. The discharge pump is arranged on an inlet side of the cooling tank and supplies a liquid coolant to the cooling tank at a predetermined flow rate. The recovery pump is arranged on an outlet side of the cooling tank and recovers a liquid coolant from the cooling tank. The heat exchanger is arranged on an outlet side of the recovery pump and cools a heated liquid coolant to a predetermined temperature and supplies a cooled liquid coolant to the discharge pump. The detector detects a value related to a pressure in the cooling tank. The controller controls the ability of the recovery pump in response to a detection signal from the detector.

Abstract: A cooling abnormality detection system for external electronic equipment includes a protection unit, a flowmeter, a water level gauge, a pump operation detector, an abnormal temperature sensor. The flowmeter detects a decrease in flow rate of the liquid coolant supplied from the electronic equipment. The water level gauge is arranged in the coolant tank to detect a decrease in water level of the liquid coolant. The pump operation detector is arranged in a pump to detect an operation of the pump. The abnormal temperature sensor detects an abnormal temperature of the electronic equipment. The protection unit discriminates a cooling abnormality when an abnormal temperature is detected by the temperature sensor during the operation of the pump and discriminates a cooling abnormality when an abnormality is detected by any one of the flow meter, the warer level gauge, and the abnormal temperature sensor during operation of the pump.

Abstract: A cooling system for electronic components includes a substrate on which electronic components are mounted. A first layer made of adhesive material is provided on a surface of the substrate opposite the components and a second layer made of a material having a relatively low melting point is provided on the first layer. Heat radiating means are provided on the second layer to outwardly radiate heat transmitted from the electronic components through the substrate, first layer and second layer.

Abstract: A cooling system for maintaining the temperature within electronic equipment has a circulation system for pumping a cooling liquid, such as water, through the electronic equipment where it picks up heat generated by the electronic equipment. The cooling liquid is pumped through a plurality of heat exchangers using a refrigerant which is, in turn, pumped through a compressor-condensor combination, each heat exchanger having approximately the same cooling capacity. A central control selects the number of heat exchangers which are to operate at any given time, on a basis of the differential in the temperature of the water being pumped into and out of the electronic equipment. This maintains a desired and relatively wide range of temperatures. A heating element selectively and controllably heats the cooled water to bring the wide range of temperatures to a selected and fixed temperature.