SOLAR HEAT COLLECTING DEVICE

PURPOSE:To realize the efficient heat collection of the device and to prevent the motor driving a circulating pump from inching running by a method wherein the start and stop and variable speed controlling of the circulating pump are performed in accordance with the respective detected values of the outside temperature, temperatures of heat transfer medium at the inlet and the outlet of a solar heat collector and insolation. CONSTITUTION:In the solar heat collecting device comprising in connecting the solar heat collector 1 consisting in disposing a plurality of vacuum glass tube type heat collecting tubes to a heat accumulator 5 through an influx pipe 4 and an efflux pipe 6, heat transfer medium thermo sensitive devices 9a and 9b are fitted at the outlet 1a and inlet 1b of the solar heat collector 1. In addition, a thermo sensitive device 11 for outside temperature detection and an insolation meter 12 are also provided and connected together with said devices 9a and 9b to a calculating controller 15. The controller 15 outputs a start or stop signal of the circulating pump 7 by calculating on the basis of an outside temperature signal and a heat transfer medium temperature difference signal and furthermore make the circulating pump 7 perform variable speed operation so as to bring the outlet temperature of the solar heat collector to the set temperature in accordance with the amount of insolation and the outside temperature.