Abstract: Provided is a air purge device that can effectively discharge air.

Abstract: This refrigeration machine comprises a compressor that compresses a refrigerant, a condenser that condenses the refrigerant which has been compressed by the compressor, an expander that expands the refrigerant which has been condensed by the condenser, a liquid film type evaporator that evaporates the refrigerant which has been expanded by the expander, and an eductor that generates flow speed difference and pressure difference in the refrigerant which has been expanded by the expander and suctions refrigerant stored in the evaporator.

Abstract: There is provided a method of manufacturing a crystal substrate, including: preparing a first crystal body which is a substrate comprising a single crystal of group III nitride produced by a vapor phase method and having a first main surface, and in which c-plane of the single crystal is curved in a concave spherical shape with a predetermined curvature; and growing a second crystal body comprising a single crystal of group III nitride on the first main surface, in a mixed melt containing an alkali metal and a group III element.

Abstract: An evaporator (2) comprising: a casing (5); a plurality of heat transfer tubes (12) which are immersed in a liquid refrigerant (RL) in a liquid-phase region (A1) and in the interior of which a fluid having a higher temperature than that of the liquid refrigerant (RL) flows; and a demister (7) which is provided so as to cover from above the liquid surface (Ls) of the liquid refrigerant (RL) accommodated in the liquid-phase region (A1), and which traps liquid droplets contained in evaporated gas refrigerant (RG). The demister (7) comprises inclined sections (13) which, when viewed in a cross section intersecting the axial line (O2) of the heat transfer tubes (12), separate from the liquid surface (Ls) toward the center portion of the casing (5) along the liquid surface (Ls).

Abstract: An evaporator includes: a vessel having a refrigerant inlet for receiving a refrigerant at a lower part of the vessel, and a refrigerant outlet for discharging the refrigerant in an evaporated state at an upper part of the vessel; and a plurality of heat-transfer tubes disposed so as to extend inside the vessel along a longitudinal direction of the vessel, and configured to transfer heat received from a fluid flowing inside the heat-transfer tubes to the refrigerant flowing outside the heat-transfer tubes. The plurality of heat-transfer tubes are disposed so that at least one downward flow passage is defined through the plurality of heat-transfer tubes or around the plurality of heat-transfer tubes, the at least one downward flow passage having a width larger than a representative interval between the plurality of heat-transfer tubes.

Abstract: An evaporator (2) comprising: a casing (5); a plurality of heat transfer tubes (12) which are immersed in a liquid refrigerant (RL) in a liquid-phase region (A1) and in the interior of which a fluid having a higher temperature than that of the liquid refrigerant (RL) flows; and a demister (7) which is provided so as to cover from above the liquid surface (Ls) of the liquid refrigerant (RL) accommodated in the liquid-phase region (A1), and which traps liquid droplets contained in evaporated gas refrigerant (RG). The demister (7) comprises inclined sections (13) which, when viewed in a cross section intersecting the axial line (O2) of the heat transfer tubes (12), separate from the liquid surface (Ls) toward the center portion of the casing (5) along the liquid surface (Ls).

Abstract: A purging device that includes a purging pipe for purging a gas mixture containing a coolant and a non-condensable gas from a chiller; a purging tank; a cooling device that has a cooling heat-transfer surface provided therein which condenses the coolant in the gas mixture and is oriented in the height direction inside the purging tank; a drainage pipe for discharging the liquid coolant inside the purging tank to the chiller; an exhaust; a purging tank pressure sensor for measuring the pressure inside the purging tank; and a control device which detects that an increase in the level of the liquid coolant inside the purging tank has occurred when the measured value from the purging tank pressure sensor decreases, and thereafter, increases to a prescribed value or higher, when condensing the coolant by cooling the interior of the purging tank using the cooling device.

Abstract: A centrifugal chiller includes a first expansion unit (23) that expands refrigerant that has been compressed and condensed, and an evaporation unit (41) that evaporates the expanded refrigerant and supplies the evaporated refrigerant to a compression unit (15). The first expansion unit (23) has an orifice (20) through which refrigerant condensed by a condensation unit (17) passes, and a flow rate regulation valve (22) that can regulate the amount of refrigerant condensed by the condensation unit (17) flowing through and that is connected in parallel with the orifice (20).

Abstract: In a method for manufacturing a group 13 nitride crystal, a seed crystal made of a group 13 nitride crystal is arranged in a mixed melt containing an alkali metal and a group 13 element, and nitrogen is supplied to the mixed melt to grow the group 13 nitride crystal on a principal plane of the seed crystal. The seed crystal is manufactured by vapor phase epitaxy. At least a part of contact members coming into contact with the mixed melt in a reaction vessel accommodating the mixed melt is made of Al2O3. An interface layer having a photoluminescence emission peak whose wavelength is longer than the wavelength of a photoluminescence emission peak of the grown group 13 nitride crystal is formed between the seed crystal and the grown group nitride crystal.

Abstract: There is provided a method of manufacturing a crystal substrate, including: preparing a first crystal body which is a substrate comprising a single crystal of group III nitride produced by a vapor phase method and having a first main surface, and in which c-plane of the single crystal is curved in a concave spherical shape with a predetermined curvature; and growing a second crystal body comprising a single crystal of group III nitride on the first main surface, in a mixed melt containing an alkali metal and a group III element.

Abstract: The purpose of the present invention is to install an economizer having a sufficient internal volume in a compact turbo refrigeration apparatus specifically using a low-pressure refrigerant, and reduce refrigerant pressure loss and enhance efficiency in the turbo refrigeration apparatus. The turbo refrigeration apparatus according to the present invention comprises: a turbo compressor which compresses a refrigerant; a condenser which condenses the compressed refrigerant; a control valve which causes the condensed refrigerant to expand; an evaporator which causes the expanded refrigerant to evaporate; and an economizer which is installed in such a manner as to be sandwiched between the condenser and the evaporator, and separates the refrigerant expanded by the control valve into gas and liquid. The economizer is installed adjacent to a curved wall, having a drum shell shape, of the condenser and/or the evaporator, the curved wall being shared with the structural wall of the economizer.

Abstract: This refrigerating machine is equipped with: a turbocompressor which compresses a refrigerant; a condenser which is equipped with one or more pipe groups configured from a plurality of heat transfer pipes through which cooling water flows, and condenses the refrigerant compressed by the turbocompressor; an expansion valve which causes the refrigerant condensed by the condenser to expand; an evaporator which causes the refrigerant expanded by the expansion valve to evaporate; a temperature sensor which detects cooling water exit temperature, which is the temperature of the cooling water flowing from at least one of the heat transfer pipes constituting the pipe group(s); and a control unit which determines, on the basis of the detection temperature of the temperature sensor, air bleeding start conditions for starting an air bleeding operation to bleed and discharge air to the outside.

Abstract: A centrifugal chiller in which a closed-cycle refrigeration cycle is formed by connecting a compressor, a condenser, an economizer and decompression means forming a multi-stage compression cycle, and an evaporator, with the refrigeration cycle being charged with a low-pressure refrigerant. The condenser and the economizer are integrated with each other by having a portion of their vessel walls form a shared wall, with the base surface of the economizer being positioned below the base surface of the condenser and above the base surface of the evaporator.

Abstract: The purpose of the present invention is to provide a refrigerator in which the capacity of an oil tank can be made smaller than in the prior art while a foaming phenomenon is addressed.

Abstract: The present invention maintains a compact evaporator size in a centrifugal chiller utilizing a low pressure refrigerant used at a maximum pressure of less than 0.2 MPaG while avoiding efficiency losses and equipment damage that result from carryover of liquid state refrigerant to the turbo compressor side.

Abstract: A purging device equipped with: a purging pipe for purging a gas mixture containing a coolant and a non-condensable gas from a chiller; a purging tank for storing the gas mixture purged from the purging pipe; a cooling device which cools the interior of the purging tank and condenses the coolant in the gas mixture; a drainage pipe for discharging the liquid coolant inside the purging tank to the chiller; an exhaust pipe for discharging the non-condensable gas in the gas mixture inside the purging tank to the exterior; and a control unit which stops operation of the purging device when the discharged non-condensable gas amount discharged from the exhaust pipe exceeds the introduced non-condensable gas amount introduced into the chiller.

Abstract: The present invention makes it possible in a centrifugal chiller utilizing a low pressure refrigerant used at a maximum pressure of less than 0.2 MPaG to effectively extract, in high concentration, non-condensible gas that has mixed into the low pressure refrigerant, and thus suppresses reductions in condensing efficiency. This condenser (3) is equipped with: a shell vessel (21) into which a low pressure refrigerant used at a maximum pressure of less than 0.

Abstract: A purging device equipped with: a purging pipe (17) for purging a gas mixture containing a coolant and a non-condensable gas from a chiller; a purging tank (40) for storing the gas mixture purged from the purging pipe (17); a cooling device (42) which cools the interior of the purging tank (40) and has a cooling heat-transfer surface (42a) provided therein which condenses the coolant in the gas mixture and is oriented in the height direction inside the purging tank (40); a drainage pipe (19) for discharging the liquid coolant inside the purging tank (40) to the chiller; an exhaust pipe (50) for discharging the non-condensable gas in the gas mixture inside the purging tank (40) to the exterior; a purging tank pressure sensor (46) for measuring the pressure inside the purging tank (40); and a control device (16) which detects that an increase in the level of the liquid coolant inside the purging tank (40) has occurred when the measured value from the purging tank pressure sensor (46) decreases, and thereafter,

Abstract: The present invention is provided with an extraction device (40) including: a cooling unit for cooling gas that has been extracted from a condenser (5) and condensing condensed gas; and an exhaust pump (48) for discharging, to the exterior, uncondensed gas that has been isolated without having been condensed by the cooling unit. A current temperature difference, which is the difference between the current saturation temperature in the condenser (5) and the current outlet temperature of a cooling water heat transfer tube (5a), and a planned temperature difference, which is a planned value, are computed. Using information on an in-tube fouling temperature difference elevation, which is a difference between the saturation temperature in the condenser (5) and the outlet temperature of the cooling water heat transfer tube (5a) and which is predetermined assuming in-tube fouling of the cooling water heat transfer tube (5a), the temperature difference elevation due to the current in-tube fouling is computed.

Abstract: This turbo chiller includes a shell-and-tube condenser; a header along a length direction of a shell is installed on a refrigerant inlet of the condenser, and openings are formed at least on both end portions of the header in the length direction, which allows high-temperature and high-pressure refrigerant gas from a compressor to be smoothly and evenly distributed to both length-direction end areas in the shell of the condenser through the header.