Claims
- 1. In a refrigeration system including a compressor, a condensor, and an evaporator operatively connected, the system comprising:
- (a) a modulating, electrically operated expansion valve connected to the inlet of the evaporator,
- (b) first and second temperature-responsive electrical sensors, the first sensor being positioned to respond to the temperature of liquid refrigerant expanded to suction pressure, and the second sensor being positioned to respond to suction line sensible temperature,
- (c) an electrical amplifier circuit connecting the sensors to the valve for modulation of the opening and closing of the valve in response to the differences in the temperatures sensed by the sensors, and
- (d) the electrical amplifier circuit including a detector for determining whether the suction saturation temperature exceeds a maximum set point, and actuating the expansion valve to close and limit the suction saturation temperature.
- 2. A refrigeration system as defined in claim 1, in which:
- (e) refrigerant-bleeding means in the system feed refrigerant at a low flow rate when the first and second sensors sense the same temperature as during start-up of the system, the bleed flow causing the sensors to sense different temperatures to cause modulation of the valve to control superheat, the first sensor being positioned to respond to the saturation temperature of the suction pressure of the bleed flow.
CROSS REFERENCE TO OTHER APPLICATIONS
This application is a division, of application Ser. No. 80,398, filed Oct. 1, 1979 now U.S. Pat. No. 4,362,027 which is a Continuation-In-Part of copending application Ser. No. 865,903 filed on Dec. 30, 1977, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
2583178 |
Huntington |
Jan 1952 |
|
3577743 |
Long |
Apr 1971 |
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Divisions (1)
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Number |
Date |
Country |
Parent |
80398 |
Oct 1979 |
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
865903 |
Dec 1977 |
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