Abstract: A heat exchanger tube (1), wherein a plurality of refrigerant passages (5) extending in the longitudinal direction of the tube are formed in a flat tube body (2) with a specified length parallel with each other in the lateral direction of the tube and, where the overall cross sectional area of the tube body (2) is (At), the overall cross sectional area of the refrigerant passage (5) is (Ac), the outer peripheral length of the tube body (2) is (L), and the overall inner peripheral length of the refrigerant passage (5) is (P), set so that the relation of Ac/At×100=30 to 55 and P/L×100=150 to 325 can be established, whereby a heat exchanging performance can be increased.

Abstract: A heat exchanger tube (1), wherein a plurality of refrigerant passages (5) extending in the longitudinal direction of the tube are formed in a flat tube body (2) with a specified length parallel with each other in the lateral direction of the tube and, where the overall cross sectional area of the tube body (2) is (At), the overall cross sectional area of the refrigerant passage (5) is (Ac), the outer peripheral length of the tube body (2) is (L), and the overall inner peripheral length of the refrigerant passage (5) is (P), set so that the relation of Ac/At×100=30 to 55 and P/L×100=150 to 325 can be established, whereby a heat exchanging performance can be increased.

Abstract: A refrigeration system including a two-stage type compressor having independent low-pressure and high-pressure compressing portions, a heat-releasing device having independent primary and secondary heat-releasing paths, an expansion valve and a cooler. The refrigerant primarily compressed by the low-pressure compressing portion is primarily released in heat by the primary heat-releasing path. The primarily heat-released refrigerant is secondarily compressed by the high-pressure compressing portion. The secondarily compressed refrigerant is secondarily released in heat by the secondary heat-releasing path to thereby obtain a low-temperature and high-pressure refrigerant. The low-temperature and high-pressure refrigerant is decompressed and expanded by an expansion valve and passes through the cooler to absorb the heat in a room air, and then returns to the low-pressure compressing portion of the compressor. In this system, the refrigerant temperature during the heat-releasing procedure can be kept low.

Abstract: In an electrolytic capacitor 1 in which a capacitor element 2 is enclosed in an external casing 3, a heat conductive material 5 having heat conductivity of 1 W/m·K or more is disposed between the external casing 3 and the capacitor element 2 so as to be in contact with them. Alternatively, in an electrolytic capacitor 1 in which a capacitor element 2 is enclosed in an external casing 3 made of aluminum, an external peripheral surface of the external casing 3 is covered with an insulation film 4.

Abstract: An upper header tank of an evaporator is formed by three plates. The outside plate has an inflow-side refrigerant-passage outwardly bulging portion whose one end portion communicates with a refrigerant inlet. The inside plate has tube insertion holes. The intermediate plate has communication holes for establishing communication between the tube insertion holes of the inside plate and the outwardly bulging portion of the outside plate. The communication holes of the intermediate plate are connected by communication portions so as to form a resin passage communicating with the outwardly bulging portion. Of all the communication portions of the refrigerant passage, a plurality of upstream communication portions are smaller in width than the remaining communication portions. The relation 0.25?A/B?0.35 is satisfied, where A represents the number of the narrow communication portions, and B represents the total number of the communication holes which form the refrigerant passage.

Abstract: A heat exchanger includes an outer tube and an inner tube having a plurality of fins for ed on an external periphery of the inner tube and disposed in the outer tube. The heat exchanger is designed to exchange heat between first fluid passing through the inner tube and second fluid passing in between the outer tube and the inner tube. A gap is formed between an internal periphery of the outer tube and a tip end of each of the plurality of fins of the inner tube. This structure can improve the heat exchanging performance and provide a heat exchanger excellent in vending workability.

Abstract: An upper header tank of an evaporator is formed by three plates. The outside plate has an inflow-side refrigerant-passage outwardly bulging portion whose one end portion communicates with a refrigerant inlet. The inside plate has tube insertion holes. The intermediate plate has communication holes for establishing communication between the tube insertion holes of the inside plate and the outwardly bulging portion of the outside plate. The communication holes of the intermediate plate are connected by communication portions so as to form a resin passage communicating with the outwardly bulging portion. Of all the communication portions of the refrigerant passage, a plurality of upstream communication portions are smaller in width than the remaining communication portions. The relation 0.25?A/B?0.35 is satisfied, where A represents the number of the narrow communication portions, and B represents the total number of the communication holes which form the refrigerant passage.

Abstract: In an electrolytic capacitor 1 in which a capacitor element 2 is enclosed in an external casing 3, a heat conductive material 5 having heat conductivity of 1 W/m·K or more is disposed between the external casing 3 and the capacitor element 2 so as to be in contact with them. Alternatively, in an electrolytic capacitor 1 in which a capacitor element 2 is enclosed in an external casing 3 made of aluminum, an external peripheral surface of the external casing 3 is covered with an insulation film 4.

Abstract: A heat exchanging tube is provided with a flat tube main body having a predetermined length and a plurality of refrigerant passages extending in a tube longitudinal direction and arranged in a tube widthwise direction. The following relational equations (a) to (c) are satisfied: W=6 to 18 mm . . . (a); Ac/At×100=50 to 70% . . . (b) and P/L×100=350 to 450% . . . (c), where “W” is a width of the tube main body, “Ac” is a total cross-sectional area of the refrigerant passages, “At” is a total cross-sectional area of the tube main body (including the refrigerant passages), “L” is an external perimeter of the tube main body and “P” is a total inner perimeter of the refrigerant passages. With this tube, enough pressure strength can be obtained and the passage resistance can be decreased while keeping the light weight, and further the heat exchanging performance can be improved.

Abstract: A heat exchanging tube is provided with a flat tube main body having a predetermined length and a plurality of refrigerant passages extending in a tube longitudinal direction and arranged in a tube widthwise direction. The following relational equations (a) to (c) are satisfied: W=6 to 18 mm . . . (a); Ac/At×100=50 to 70% . . . (b) and P/L×100=350 to 450% . . . (c), where “W” is a width of the tube main body, “Ac” is a total cross-sectional area of the refrigerant passages, “At” is a total cross-sectional area of the tube main body ( including the refrigerant passages), “L” is an external perimeter of the tube main body and “P” is a total inner perimeter of the refrigerant passages. With this tube, enough pressure strength can be obtained and the passage resistance can be decreased while keeping the light weight, and further the heat exchanging performance can be improved.

Abstract: An evaporator using a CO2 refrigeration that prevents a raise in vapor quality of refrigeration in an evaporator passage to obtain heat exchanging efficiency. The evaporator for use in a refrigeration system includes a refrigerant inlet for introducing a refrigerant, a refrigerant outlet for discharging the refrigerant, and an evaporator passage for causing the refrigerant introduced via the refrigerant inlet to evaporate and leading the refrigerant to the refrigerant outlet. An intermediate outlet is provided at an intermediate portion of the evaporator passage. A refrigerant high in vapor quality among the refrigerant passing through the intermediate portion from the refrigerant inlet flows out of the intermediate outlet to prevent a raise in vapor quality of refrigerant.

Abstract: The invention provides an ebullition cooling device 1 for a heat generating component B which device comprises a boiling unit 2 for boiling a refrigerant A contained therein with the heat generated by the heat generating component B as attached to an outer surface of the unit, a condensing unit 3 disposed above the boiling unit 2 for condensing a refrigerant vapor A1 flowing thereinto from the boiling unit 2 by heat exchange with an external fluid C, and a communication pipe 4 interconnecting the units 2, 3 and having a refrigerant vapor channel 41 and a refrigerant condensate channel 42 therein. The cooling device 1 can be designed with greater freedom, and is therefore fully useful for electronic devices which are compacted or higher in complexity, smaller in the amount of refrigerant to be enclosed therein and outstanding in heat dissipating performance.

Abstract: A heat exchanging tube is provided with a flat tube main body having a predetermined length and a plurality of refrigerant passages extending in a tube longitudinal direction and arranged in a tube widthwise direction. The following relational equations (a) to (c) are satisfied: W=6 to 18 mm . . . (a); Ac/At×100=50 to 70% . . . (b) and P/L×100=350 to 450% . . . (c), where “W” is a width of the tube main body, “Ac” is a total cross-sectional area of the refrigerant passages, “At” is a total cross-sectional area of the tube main body ( including the refrigerant passages), “L” is an external perimeter of the tube main body and “P” is a total inner perimeter of the refrigerant passages. With this tube, enough pressure strength can be obtained and the passage resistance can be decreased while keeping the light weight, and further the heat exchanging performance can be improved.

Abstract: A refrigeration system including a two-stage type compressor having independent low-pressure and high-pressure compressing portions, a heat-releasing device having independent primary and secondary heat-releasing paths, an expansion valve and a cooler. The refrigerant primarily compressed by the low-pressure compressing portion is primarily released in heat by the primary heat-releasing path. The primarily heat-released refrigerant is secondarily compressed by the high-pressure compressing portion. The secondarily compressed refrigerant is secondarily released in heat by the secondary heat-releasing path to thereby obtain a low-temperature and high-pressure refrigerant. The low-temperature and high-pressure refrigerant is decompressed and expanded by an expansion valve and passes through the cooler to absorb the heat in a room air, and then returns to the low-pressure compressing portion of the compressor. In this system, the refrigerant temperature during the heat-releasing procedure can be kept low.

Abstract: A heat exchanger according to the present invention includes a pair of header tanks 10a and 10b and a plurality of heat exchanging tubes 30 disposed between the header tanks and arranged in parallel. The header tank 10 and 10b is provided with partitioning walls 15 integrally formed to the header tank along the longitudinal direction. The inside space of the header tank is divided by the partitioning walls 15 into tank partions 11 to 014. Refrigerant turning communication apertures 17 are formed in the predetermined partitioning wall 15. The refrigerant passages 35 of the heat exchanging tube 30 are grouped so as to correspond to each tank portion of the header tank 10a and 10b to thereby form a plurality of passes P1 to P4. The refrigerant introduced into the first tank portion 11 of one of the header tanks 10a passes through each passes P1 to P4 in this order from the rear side toward the front side, and then introduced into the fourth tank portion 14 of the other of the header tanks 10b.

Abstract: The invention provides an ebullition cooling device 1 for a heat generating component B which device comprises a boiling unit 2 for boiling a refrigerant A contained therein with the heat generated by the heat generating component B as attached to an outer surface of the unit, a condensing unit 3 disposed above the boiling unit 2 for condensing a refrigerant vapor A1 flowing thereinto from the boiling unit 2 by heat exchange with an external fluid C, and a communication pipe 4 interconnecting the units 2, 3 and having a refrigerant vapor channel 41 and a refrigerant condensate channel 42 therein. The cooling device 1 can be designed with greater freedom, and is therefore fully useful for electronic devices which are compacted or higher in complexity, smaller in the amount of refrigerant to be enclosed therein and outstanding in heat dissipating performance.

Abstract: The invention relates to heat sinks made of finned aluminum extrudates and useful for electronic devices and information devices having an electronic device incorporated therein. The heat sink of the invention made of a finned aluminum extrudate comprises a base plate, and fins arranged in parallel and provided on one surface thereof. The base plate is 25 to 400 mm in width, 25 to 400 mm in length and 2 to 5 mm in thickness, and the fins are 1 to 30 mm in height, 1 to 1.9 mm in interval and 0.1 to 0.8 mm in thickness. The thickness of the fins is reduced within a predetermined range according to the invention to thereby ensure diminished resistance to the flow of air and improved radiation performance. This also renders the heat sink lightweight, serving to reduce the size and weight of electronic devices and information devices.

Abstract: A heat exchanger tube (1), wherein a plurality of refrigerant passages (5) extending in the longitudinal direction of the tube are formed in a flat tube body (2) with a specified length parallel with each other in the lateral direction of the tube and, where the overall cross sectional area of the tube body (2) is (At), the overall cross sectional area of the refrigerant passage (5) is (Ac), the outer peripheral length of the tube body (2) is (L), and the overall inner peripheral length of the refrigerant passage (5) is (P), set so that the relation of Ac/At×100=30 to 55 and P/L×100=150 to 325 can be established, whereby a heat exchanging performance can be increased.

Abstract: The present invention provides particulate alumina having a mean particle size corresponding to a volume-cumulative (50%) mean particle size (D50) of 1.5 to 4 &mgr;m and a ratio (D90/D1O) of D90 to D10 of 2.5 or less. The alumina contains secondary particles having a particle size of at least 10 &mgr;m in an amount of 0.1 mass % or less; secondary particles having a particle size of 0.5 &mgr;m or less in an amount of 5 mass % or less; and an &agr;-phase as a predominant phase.fluoride. The present invention also provides a method for producing the particulate alumina.