Brayton cycle type refrigerating apparatus

Patent metadata

Field	Value
Publication number	US-2016018134-A1
Application number	US-201414773798-A
Country	US
Kind code	A1
Filing date	Mar 20, 2014
Priority date	May 31, 2013
Publication date	Jan 21, 2016
Grant date	—

Abstract

To provide a Brayton cycle type refrigerating apparatus using multiple stages of compressors and having a good response without reduction in efficiency due to change in heat load of the object to be cooled, the Brayton cycle type refrigerating apparatus ( 100 ) according to the present invention comprises, on a refrigerant line ( 101 ), multiple stages of compressors ( 102 a, 102 b, 102 c ), a temperature sensor ( 160 ) for detecting heat load of an object to be cooled, and a buffer tank ( 111 ) provided between a low pressure line ( 109 ) and a high pressure line ( 110 ), wherein a flow rate of the refrigerant in the refrigerant line is controlled by controlling opening degrees of valves ( 112, 113 ) to adjust the cooling capacity.

First claim

1 . A Brayton cycle type refrigerating apparatus utilizing a Brayton cycle having multiple stages of compressors arranged in series on a refrigerant line for generating cool heat by using a refrigerant compressed by the compressors to cool a secondary refrigerant, comprising:
a heat load detecting device for detecting a heat load of an object to be cooled; a buffer tank provided between a low pressure line in which the refrigerant before being compressed by the compressors flows and a high pressure line in which the refrigerant after being compressed by the compressors flows; a first valve provided on an inlet side of the buffer tank and capable of controlling an inflow rate of the refrigerant into the buffer tank; a second valve provided on an outlet side of the buffer tank and capable of controlling an outflow rate of the refrigerant from the buffer tank; and a control device for controlling an opening degree of the first valve and an opening degree of the second valve, wherein the control device is configured, when a change in the heat load of the object to be cooled is detected by the heat load detecting device, to adjust the opening degree of the first valve and the opening degree of the second valve to change a flow rate of the refrigerant flowing in the Brayton cycle.

2 . The Brayton cycle type refrigerating apparatus according to claim 1 ,
wherein the high pressure line is a line to which the refrigerant is discharged from a compressor disposed at the lowermost stream position among the compressors, and wherein the low pressure line is a line through which the refrigerant is supplied to a compressor disposed at the uppermost stream position among the compressors.

3 . The Brayton cycle type refrigerating apparatus according to claim 2 , further comprising a cool heat recovering heat exchanger for exchanging heat between the refrigerant compressed by the compressors and the refrigerant after cooling the object to be cooled,
wherein the high pressure line has a branching line branched from a position between the at least one of the compressors and the cold heat recovering heat exchanger.

4 . The Brayton cycle type refrigerating apparatus according to claim 1 , wherein the control device is configured, when the change rate of the heat load detected by the heat load detecting device is greater than a preliminarily set prescribed value, to control a rotational speed of at least one of the compressors and a rotational speed of an expander, and then to adjust the opening degree of the first valve and the opening degree of the second valve.

5 . The Brayton cycle type refrigerating apparatus according to claim 1 ,
wherein a cooling part of the Brayton cycle is configured to cool, by means of a heat exchanger, a secondary refrigerant circulating through the object to be cooled, and wherein the heat load detecting device comprises a temperature sensor provided on a line in which the secondary refrigerant flows.

6 . The Brayton cycle type refrigerating apparatus according to claim 1 ,
wherein the multiple stages of compressors comprise a first compressor, a second compressor and a third compressor, arranged in series in this order from the upstream side, wherein the first compressor and the second compressor are connected to an output shaft of a first electric motor, and wherein the third compressor and the expander are connected to an output shaft of a second electric motor.

Assignees

• Maekawa Seisakusho Kk

Inventors

• Ueda Shota
• Machida Akito
• Kudo Mizuo
• Nakamura Naoko

Classifications

• F25B7/00 Primary

  Compression machines, plants or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit (F25B9/00 takes precedence) · CPC title

• F02C1/10 Primary

  Closed cycles · CPC title

• F25B2700/21163

  of the refrigerant at the outlet of the condenser · CPC title

• F25B2600/2523

  Receiver valves · CPC title

• F25B40/00

  Subcoolers, desuperheaters or superheaters · CPC title