SUPERCRITICAL REFRIGERATION CYCLE SYSTEM

• US 20080314071A1
• Filed: 08/22/2006
• Published: 12/25/2008
• Est. Priority Date: 08/23/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ohta, Hiromi, Murase, Yoshinori
• Granted Patent: US 7,467,525 B1
• Time in Patent Office: Days
• US Class Current: 62/498
• CPC Class Codes: F25B 2309/061 with cycle highest pressure above the supercritical pressure
• CPC Class Codes: F25B 2341/063 Feed forward expansion valves
• CPC Class Codes: F25B 2600/2501 Bypass valves
• CPC Class Codes: F25B 2700/2117 of an evaporator
• CPC Class Codes: F25B 2700/21174 of the refrigerant at the inlet of the evaporator
• CPC Class Codes: F25B 2700/21175 of the refrigerant at the outlet of the evaporator
• CPC Class Codes: F25B 40/00 Subcoolers, desuperheaters or superheaters
• CPC Class Codes: F25B 41/39 Dispositions with two or more expansion means arranged in series, i.e. multi-stage expansion, on a refrigerant line leading to the same evaporator
• CPC Class Codes: F25B 5/02 arranged in parallel
• CPC Class Codes: F25B 5/04 arranged in series
• CPC Class Codes: F25B 9/008 the refrigerant being carbon dioxide

Abstract

A supercritical refrigeration cycle system (10) having a simplified flow path configuration comprises a compressor (1) for sucking in and compressing a refrigerant, a radiator (2) for radiating the heat of the high-pressure refrigerant discharged from the compressor (1), a high-pressure control valve (5) and a superheat control valve (12) into which the high-pressure refrigerant flowing out of the radiator (2) flows after being distributed, a first evaporator (6) for evaporating the influent refrigerant decompressed by the high-pressure control valve (5), and a second evaporator (9) for evaporating the influent refrigerant decompressed by the superheat control valve (12). The outlet of the second evaporator (9) and the inlet of the first evaporator (6) are connected to each other by the refrigerant path (13) in such a manner that the refrigerant flowing out of the second evaporator (9) flows into the first evaporator (6). An increase in the blowout air temperature can be reduced by controlling the refrigerant flowing in each of the plurality of the evaporators.

Claims

1. A supercritical refrigeration cycle system of vapor compression type with pressure in the refrigeration cycle reaching and exceeding a critical pressure of a refrigerant, the supercritical refrigeration cycle system comprising:

a compressor for sucking in and compressing the refrigerant;

a radiator for radiating heat of the refrigerant discharged from the compressor;

a plurality of decompressors into which the refrigerant discharged from the radiator flows;

a first evaporator for evaporating refrigerant decompressed by the first decompressor; and

a second evaporator for evaporating refrigerant decompressed by the second decompressor;

wherein the refrigerant flowing out of one of the first evaporator and the second evaporator flows into the other of the first evaporator and the second evaporator.

2. A supercritical refrigeration cycle system according to claim 1, wherein one of the plurality of the decompressors comprises a high-pressure control valve for maintaining a high pressure to maximize a coefficient of performance of the refrigeration cycle.

3. A supercritical refrigeration cycle system according to claim 1,

wherein the refrigerant flowing out of the second evaporator flows into the first evaporator, and the second decompressor comprises a mechanical superheat control valve for controlling a superheat amount of the refrigerant at an outlet of the second evaporator.

4. A supercritical refrigeration cycle system according to claim 1,

wherein the refrigerant flowing out of the second evaporator flows into the first evaporator, and the second decompressor comprises one of a fixed diaphragm unit and a differential pressure valve with an opening area thereof changeable by pressure before and after a diaphragm mechanism.

5. A supercritical refrigeration cycle system according to claim 1,

wherein the refrigerant flowing out of the second evaporator flows into the first evaporator and the second decompressor comprises an electrical expansion valve.

6. A supercritical refrigeration cycle system according to claim 5,

wherein an opening degree of the electrical expansion valve is controlled based on temperature information of the refrigerant before and after the second evaporator.

7. A supercritical refrigeration cycle system of vapor compression type with pressure in the refrigeration cycle reaching and exceeding a critical pressure of a refrigerant, the supercritical refrigeration cycle system comprising:

a compressor for sucking in and compressing the refrigerant;

a radiator for radiating heat of the refrigerant discharged from the compressor;

a plurality of refrigerant paths for distributing refrigerant flowing out of the radiator;

a first evaporator and a second evaporator for evaporating the refrigerant distributed from the plurality of refrigerant paths; and

an accumulator for separating inflowing refrigerant into a gas-phase refrigerant and a liquid-phase refrigerant and supplying the gas-phase refrigerant to come compressor,

wherein the plurality of the refrigerant paths include a bypass allowing decompressed refrigerant to flow into the accumulator and a first distribution path and a second distribution path for distributing the refrigerant to the first evaporator and the second evaporator, respectively,

the system further comprising a superheat control valve for controlling a superheat amount of at least one of the refrigerant at an outlet of the first evaporator and the refrigerant at an outlet of the second evaporator.

8. A supercritical refrigeration cycle system according to claim 7,

wherein the bypass includes a high-pressure control valve for maintaining a high pressure to maximize a coefficient of performance of the refrigeration cycle.

9. A supercritical refrigeration cycle system according to claim 7,

wherein the bypass includes one of a fixed diaphragm unit and a differential pressure valve having an opening area variable by a pressure before and after a fixed diaphragm mechanism.