CONTROL METHOD OF PRESSURE MAINTENANCE UNIT FOR HEATING AND COOLING SYSTEM INCLUDING A PLURALITY OF SENSORS

摘要

PURPOSE: A control method of a pressure maintenance facility for cooling and heating system equipped with a plurality of sensors is provided to precisely and reliably control the pressure by excluding an abnormal value sensor after detecting the abnormality of a specific sensor using more than two measuring sensors. CONSTITUTION: A control method of a pressure maintenance facility for cooling and heating system comprises the following steps. The inner pressure of a first expansion tank is measured through a first measuring sensor. The inner pressure of a second expansion tank is measured through a second measuring sensor. The pipe pressure of a return pipe system is measured through a third measuring sensor. The absolute difference value between the measured inner pressure of the expansion tank and the measured pip pressure of a return pipe system are calculated and the measurement offset is generated. The generated measurement offset between each measuring sensor is compared with a predetermined set variation value. According to the comparison result of the measurement offset and the predetermined offset, the abnormality of each measuring sensor is determined. The abnormal determined measuring sensor, the measuring value of the other measuring sensor except for the measurement value of the third sensor and the mean value thereof is outputted as the inner pressure control reference value of each expansion tank.