Refrigeration system utilizing incomplete evaporation of refrigerant in evaporator

• US 6,748,755 B2
• Filed: 12/28/2000
• Issued: 06/15/2004
• Est. Priority Date: 03/09/2000
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Ishimine, Junichi, Kubo, Hideo, Suzuki, Masahiro, Wei, Jie, Mochizuki, Masahiro, Kawashima, Hisashi, Udagawa, Yoshiaki
• Primary Examiner(s): Tapolcai, William E.
• Assistant Examiner(s): Ali, Mohammad M.
• Application Number:
  US09/749,622
• Publication Number:
  US 20010020365A1
• Time in Patent Office: 1,265 Days
• Field of Search: 624/98, 625/24, 622/25, 622/27, 622/18
• US Class Current: 62/225
• CPC Class Codes: F25B 2600/21 Refrigerant outlet evaporator temperature
• CPC Class Codes: F25B 39/02 Evaporators
• CPC Class Codes: F25D 19/006 Thermal coupling structure or interface
• CPC Class Codes: F28D 15/0266 with separate evaporating and condensing chambers connected by at least one conduit; Loop-type heat pipes; with multiple or common evaporating or condensing chambers F28D15/043 takes precedence
• CPC Class Codes: F28F 13/06 by affecting the pattern of flow of the heat-exchange media F28F13/003 takes precedence; static flow control means in header boxes F28F9/026
• CPC Class Codes: F28F 3/12 Elements constructed in the shape of a hollow panel, e.g. with channels F28D1/02, F28D1/03 take precedence
• CPC Class Codes: H01L 23/427 Cooling by change of state, e.g. use of heat pipes by liquefied gas H01L23/445
• CPC Class Codes: H01L 23/467 by flowing gases, e.g. air H01L23/473 takes precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 7/20309 Evaporators

Abstract

A refrigeration system allows the refrigerant to circulate through a closed circulation channel. A dry evaporator is incorporated in the circulation channel. The dry evaporator is designed to keep a quality smaller than 1.0 in evaporating the refrigerant. The quantity of heat transfer per unit area, namely, a heat transfer coefficient depends on the quality. The heat transfer coefficient remarkably drops when the quality of the refrigerant exceeds a predetermined threshold level before the quality actually reaches 1.0. The quality of the refrigerant kept below the predetermined threshold level during vaporization of the refrigerant in the dry evaporator allows a reliable establishment of a higher performance of cooling. On the other hand, if a refrigerant completely evaporates in a dry evaporator in a conventional manner, the heat transfer coefficient of the refrigerant remarkably drops after the quality of the refrigerant exceeds the predetermined threshold level. Accordingly, the conventional dry evaporator is forced to absorb heat at a lower heat transfer coefficient, as compared with the present dry evaporator.

Claims

1. A refrigeration system comprising:

a circulation channel through which a refrigerant circulates;

an evaporator incorporated in the circulation channel and contacting a target heating object at its bottom plate;

a vaporization chamber defined within the dry evaporator for inducing a flow of the refrigerant along the bottom plate in a horizontal direction; and

a flow controller incorporated in the circulation channel for discharging the refrigerant at a flow enough to establish a gas-liquid separation within the vaporization chamber.

2. A refrigeration system comprising:

a circulation channel through which a refrigerant circulates;

a dry evaporator incorporated in the circulation channel and contacting a target heating object at its vertical heat transfer plate;

a vaporization chamber defined adjacent the heat transfer plate within the dry evaporator;

a refrigerant inlet opened at an inner surface of the vaporization chamber;

a refrigerant outlet opened at the inner surface of the vaporization chamber at a location above the refrigerant inlet;

a plurality of fins integrally formed on the heat transfer plate within the vaporization chamber so as to define a plurality of refrigerant passages respectively extending in a vertical direction from the refrigerant inlet toward the refrigerant outlet; and

a flow controller incorporated in the circulation channel for discharging the refrigerant at a flow enough to establish a gas-liquid separation within the vaporization chamber.

3. The refrigeration system according to claim 2, further comprising:

a bypass opening formed in the dry evaporator so as to open at a lowest position in the vaporization chamber;

a duct connected to the dry evaporator so as to define a discharge channel extending from the refrigerant outlet; and

a bypass channel connecting the bypass opening and the discharge channel to each other.

4. A refrigeration system comprising:

a circulation channel through which a refrigerant circulates;

a dry evaporator incorporated in the circulation channel and defining a vaporization chamber between a vertical heat transfer plate and a vertical back plate;

a partition plate disposed between the heat transfer plate and the back plate so as to divide an upper portion of the vaporization chamber into an introduction space adjacent the heat transfer plate and a discharge space adjacent the back plate;

a refrigerant inlet opened at an inner surface of the introduction space;

a refrigerant outlet opened at an inner surface of the discharge space; and

a flow controller incorporated in the circulation channel for discharging the refrigerant at a flow enough to establish a gas-liquid separation within the vaporization chamber, wherein

a depth of a lower portion of the vaporization chamber is set larger than a space measured between the heat transfer plate and the partition plate, said depth measured from a lower edge of the partition plate in a vertical direction.

5. A The refrigeration system comprising:

A circulation channel through which a refrigerant circulates; and

an evaporator incorporated in the circulation channel and is designed to always keep a quality smaller than 85 percent in evaporating the refrigerant.

6. The refrigeration system according to claim 5, further comprising a subsidiary dry evaporator incorporated in the circulation channel downstream of the evaporator.

7. The refrigeration system according to claim 5, further comprising:

a refrigerant outlet defined in the dry evaporator for discharging the refrigerant of gas-liquid mixture state; and

a gas-liquid separation filter incorporated in the refrigerant outlet.