Control algorithm for electronic expansion valve modulation

• Main Authors: DEROY, ROBERT M, PATEL, TEJENDRA, SCHRODER, BRUCE R, ERNST, JEFFREY, COUSSEY KODJOVI
• Format: Patent
• Language: English; French; German
• Published: 01.06.2016
• Subjects: BLASTING; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS,e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USERAPPLICATIONS; COMBINED HEATING AND REFRIGERATION SYSTEMS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEAT PUMP SYSTEMS; HEATING; LIGHTING; LIQUEFACTION SOLIDIFICATION OF GASES; MANUFACTURE OR STORAGE OF ICE; MECHANICAL ENGINEERING; REFRIGERATION MACHINES, PLANTS OR SYSTEMS; REFRIGERATION OR COOLING; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; WEAPONS

An electronic expansion valve (EEV) is employed in refrigeration systems to regulate the flow of refrigerant through an evaporator. The position of the EEV is controlled through a first control loop that generates a first position signal based on superheat feedback associated with the refrigeration system, and a second control loop that generates a second position signal based on pressure feedback associated with the refrigeration system . The larger o the first position signal and the second position signal is selected to control the position of the EEV value, and the selected position signal is provided in feedback to both the first control loop and the second control loop.