TEMPERATURE CONTROL METHOD FOR HEAT ACCUMULATING TANK

PURPOSE:To suppress heat loss and make it possible to control a tank temp. to a target temperature by predicting an amount of air conditioning load for tomorrow from the amount of air conditioning load of today and actual air conditioning load in the past and conducting heating by using midnight electric power. CONSTITUTION:From an air conditioning load Lp actually handled in the past which is stored in a memory 15 and an air conditioning load Lt at every hour of today a required air conditioning load at every hour of tomorrow is estimated, and at the same time an estimated load is stored in the memory 15. By storing a mathematical formula which approximates the relation between the load percentage and a required temperature of fed water beforehand in a small computer a required temperature of fed water can be easily calculated. A calculated temperature as a target the temperatures at the inlet and outlet of a heat accumulating tank and heat source 3 are controlled in the time span of the midnight electric power and the time to start the heat source 3 is determined so that the heat source 3 is operated as many hours as required by amount of heat accumulation which is calculated from the average temperature at present in the heat accumulating tank.