Estimating operating parameters of vapor compression cycle equipment
First Claim
1. In vapor compression equipment having a compressor, a condenser, an expansion device and an evaporator arranged in succession and connected via a conduit in a closed loop for circulating refrigerant through the closed loop, said equipment operating within its nominal vapor compression cycle parameters, a process for determining the operating efficiency of the system, the process comprising the steps of:
- measuring liquid line pressure, suction line pressure, suction line temperature, and liquid line temperature;
obtaining the suction dew point and discharge dew point temperatures from the suction line and liquid line pressures;
obtaining the suction line superheat;
obtaining the mass flow rate that corresponds to the compressor in the vapor compression cycle for the dew point temperatures and suction line superheat;
obtaining the enthalpies at the suction line and at the inlet of the evaporator; and
calculating the capacity of the vapor compression cycle from the mass flow rate and the enthalpies across the evaporator.
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Accused Products
Abstract
A process for estimating the capacity and the coefficient of performance by taking common measurements and using compressor manufacturer'"'"'s performance data is presented. A process for determining a capacity index and an efficiency index for a vapor compression cycle relative to desired operating conditions.
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Citations
21 Claims
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1. In vapor compression equipment having a compressor, a condenser, an expansion device and an evaporator arranged in succession and connected via a conduit in a closed loop for circulating refrigerant through the closed loop, said equipment operating within its nominal vapor compression cycle parameters, a process for determining the operating efficiency of the system, the process comprising the steps of:
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measuring liquid line pressure, suction line pressure, suction line temperature, and liquid line temperature;
obtaining the suction dew point and discharge dew point temperatures from the suction line and liquid line pressures;
obtaining the suction line superheat;
obtaining the mass flow rate that corresponds to the compressor in the vapor compression cycle for the dew point temperatures and suction line superheat;
obtaining the enthalpies at the suction line and at the inlet of the evaporator; and
calculating the capacity of the vapor compression cycle from the mass flow rate and the enthalpies across the evaporator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. The process of estimating the annual operating costs of a vapor compression cycle system once EI and CI are known, the process comprising the steps of:
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calculating the capacity of the system, by multiplying the nominal unit capacity, as published by the manufacturer, by the capacity index;
calculating the annual energy consumption of the unit by means of its nominal capacity, its SEER, the calculated capacity and efficiency indices, and the estimated percentage of the power used by for purposes other than compressing the gas in the compressor;
calculating the actual annual running time of the unit as the ratio of the nominal annual running time over the capacity index;
estimating the annual operating costs by multiplying the actual annual running time of the unit, the electricity price, and the calculated energy consumption.
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20. In a vapor compression cycle having a compressor, a condenser, an expansion device and an evaporator arranged in succession and connected via conduit in a closed loop in order to circulate refrigerant through the closed loop, said vapor compression cycle, a predetermined process for determining if the compressor is operating near design performance, the process comprising the steps of:
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measuring liquid line pressure and suction line pressure;
obtaining the suction and discharge dew point temperatures;
obtaining the theoretical current draw of compressor through the ARI Standard 540-1999 equation;
measure actual current draw in all legs leading to compressor;
comparing actual current draw to theoretical current draw to establish whether compressor is operating near design performance. - View Dependent Claims (21)
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Specification