| 摘要 |
A method and apparatus to determine the pressure of a supercritical refrigerant within a heat exchanger of a transcritical vapor compression system. A plurality of measurements, e.g., temperature, are obtained at spaced locations on the heat exchanger and the location of the minimum temperature gradient, i.e., maximum specific heat value of the refrigerant, is determined ("the inflection point"). Obtaining the refrigerant temperature at the inflection point allows the refrigerant pressure to be determined. Alternatively, the temperature of the refrigerant at a second point can be determined together with the change in specific enthalpy between the inflection point and the second point to thereby determine the pressure of the refrigerant. The system can be regulated by controlling the location of the inflection point or by controlling the temperature difference of the refrigerant at the inflection point and a second point, e.g., the outlet of the heat exchanger. |
