Systems and Methods for Operating a Refrigeration System

Abstract

Methods and systems for operating a refrigeration system for refrigerating a product are provided. A first temperature of the refrigerant downstream of a condenser and upstream of an evaporator may be obtained. A first pressure of the refrigerant downstream of the condenser and upstream of the evaporator may be obtained. A second pressure of the refrigerant downstream of the evaporator and upstream of a compressor and/or a temperature of the product being refrigerated may be obtained. A first valve, disposed between the condenser and the evaporator, may be controlled based on the first temperature and the first pressure to maintain a pre-determined cooling set-point for the refrigeration system. A second valve of the refrigeration system, coupled to the compressor, may be controlled based on the second pressure or the temperature of the product to optimize a capacity of a compressor of the refrigeration system.

What is claimed is: 
     
         1 . A refrigeration system for refrigerating a product, comprising:
 a condenser;   an evaporator disposed downstream of the condenser;   a compressor disposed downstream of the evaporator;   a first transducer disposed immediately downstream of the condenser, the first transducer configured to obtain a first temperature of a refrigerant downstream of the condenser and upstream of the evaporator;   a second transducer disposed immediately downstream of the condenser, the second transducer configured to obtain a first pressure of the refrigerant downstream of the condenser and upstream of the evaporator;   a third transducer disposed immediately downstream of the evaporator, the third transducer configured to obtain a second pressure of the refrigerant downstream of the evaporator and upstream of the compressor or a temperature of the product being refrigerated; and   a controller communicatively coupled to the first, second, and third transducers, the controller configured to control a first control valve disposed downstream of the condenser and upstream of the evaporator based on the obtained first temperature and the first pressure to maintain a pre-determined cooling set-point, the controller configured to control a second control valve coupled to the compressor based on the obtained second pressure or the temperature of the product to optimize a capacity of compressor.   
     
     
         2 . The refrigeration system of  claim 1 , wherein the first control valve comprises an electronic stepper valve configured to reduce the pressure of the refrigerant. 
     
     
         3 . The refrigeration system of  claim 1 , wherein the second control valve comprises a solenoid valve configured to load or unload the compressor. 
     
     
         4 . The refrigeration system of  claim 1 , further comprising: a fan arranged to pull a refrigeration medium across the condenser; and a fan drive configured to control a speed of the fan, wherein the controller is configured to control the fan drive based on the obtained first pressure. 
     
     
         5 . The refrigeration system of  claim 1 , further comprising a hand-held device communicatively coupled to the controller, the hand held device configured to allow a user to remotely monitor the refrigeration system. 
     
     
         6 . The refrigeration system of  claim 1 , wherein the controller is configured to calculate a current cooling level of the refrigerant downstream of the condenser and upstream of the evaporator based on the obtained first temperature and first pressure, and wherein the controller is configured to control the first valve of the refrigeration system based on the calculated cooling level. 
     
     
         7 . The refrigeration system of  claim 1 , wherein the controller is configured to compare the current cooling level of the refrigerant with the pre-determined cooling set-point, the pre-determined cooling set-point being the desired cooling level for the refrigerant when leaving the condenser, and wherein the controller is configured to control the first valve of the refrigeration system based on the comparison. 
     
     
         8 . The refrigeration system of  claim 1 , wherein the controller is configured to compare the obtained second pressure or temperature with a pre-determined second pressure or temperature set-point, and wherein the controller is configured to control the second control valve of the refrigeration system based on the comparison. 
     
     
         9 . The refrigeration system of  claim 8 , wherein the controller is configured to energize the solenoid valve when the obtained second pressure or temperature is less than the pre-determined second pressure or temperature set-point, and de-energize the solenoid valve when the obtained second pressure or temperature is greater than the pre-determined second pressure or temperature set-point.