| 摘要 |
A method is described for distinguishing non-condensables from refrigerant over-charge, and refrigerant restrictions from refrigerant under-charge of a cooling system and calculating an amount of refrigerant to be added or removed to the cooling system for optimal performance. Expanded target temperature split and target superheat tables and delta superheat tolerances are provided based on laboratory data and mathematical algorithms. The methods may apply to Fixed Expansion Valve (FXV) and Thermostatic Expansion Valve (TXV) systems and may include making and displaying a diagnostic recommendation regarding non-condensables, refrigerant restrictions, or refrigerant adjustment based upon measurements of return-air wetbulb and drybulb temperatures, condenser entering air temperature, refrigerant suction line temperature, refrigerant liquid line temperature, refrigerant vapor and liquid line pressures, and refrigerant superheat and subcooling temperatures. |
| 主权项 |
1. A method for improving air conditioning system efficiency, the method comprising:
expanding temperature split and superheat tables into previously undefined values using laboratory test data; looking up target superheat in the expanded superheat tables; expanding the delta superheat tolerance when target superheat is low to avoid overcharging; performing at least one correction to the air condition system selected from:
determining the presence of non-condensables in the air conditioning system by simultaneously evaluating four parameters: 1) superheat, 2) subcooling, 3) condenser saturation temperature minus condenser entering air temperature as a function of outdoor air temperature and condenser heat exchanger surface area as a function of SEER rating, and 4) evaporator saturation temperature as a function of outdoor air temperature and evaporator heat exchanger surface area as a function of SEER rating, and:
if non-condensables are present, then recovering refrigerant, removing non-condensables from the air conditioning system, evacuating to 500 microns, recharging, and continuing;if non-condensables are not present, determining an estimate of refrigerant over-charge by simultaneously evaluating three parameters: 1) superheat, 2) subcooling, and 3) condenser saturation temperature minus condenser entering air temperature as a function of outdoor air temperature and condenser heat exchanger surface area as a function of SEER rating, and adjusting the refrigerant level based on the over-charge estimate; anddetermining the presence of restrictions in the air conditioning system by simultaneously evaluating four parameters: 1) superheat, 2) subcooling, 3) condenser saturation temperature minus condenser entering air temperature as a function of outdoor air temperature and condenser heat exchanger surface area as a function of SEER rating, and 4) evaporator saturation temperature as a function of outdoor air temperature and evaporator heat exchanger surface area as a function of SEER rating, and:
if restrictions are present, then recovering refrigerant, removing restrictions from the air conditioning system, evacuating to 500 microns, recharging, and continuing; andif restrictions are not present, determining an estimate of refrigerant under-charge by simultaneously evaluating three parameters: 1) superheat, 2) subcooling, and 3) evaporator saturation temperature as a function of outdoor air temperature and evaporator heat exchanger surface area as a function of SEER rating, and adjusting the refrigerant level based on the under-charge estimate. |
