| 摘要 |
PURPOSE:To accurately control the valve opening by controlling a reversible proportionate expansion valve at every timing pulse, and controlling in the reverse direction at more than the maximum value of dispersion of hysteresis of the valve in a case when driven in a direction opposite to a previous direction of the valve operation. CONSTITUTION:In a case where a power source 4 of a reversible proportionate expansion valve disposed in a freezing cycle, respective outputs from a temperature sensor 6 and a pressure sensor 7 which detect the temperature and pressure on the outlet side of an evaporator are inputted to a controller 16 via temperature-voltage signal and pressure-voltage signal transducers 13, 14 and an A/D transformer 15. Here, the difference between a temperature TE of refrigerant and a pressure equivalent temperature TP of the refrigerant is computed to obtain the degree of super-heating SH, and have it memorized. When the direction of operation of the valve is same between the previous and the following valve operation, a power source 4 is controlled relative to the deviation of said degree of superheating SH, while in a case the directions are opposite, control is made by adding a signal of more than the maximum value of the dispersion of hysteresis to an electrical signal which corresponds to said deviation. |
