PROCESS AND DEVICE FOR CONVERTING SOLAR ENERGY TO HEAT

摘要

In a process for converting solar energy into heat a solar collector is employed, which consists of a plurality of mutually-coupled collector elements placed on the outside of a building or the like and coupled to a heat transfer fluid network. Each of these collector elements comprises a collector channel located on the bottom of a collector chamber delimited by a transparent cover, which collector chamber normally is connected to a high-temperature reservoir via a connecting line, until a control valve arrangement is reversed and the collector channel is disconnected from the high-temperature reservoir and connected to a low-temperature reservoir for heat pump operation when the temperature of the circulating heat transfer fluid falls below a predetermined minimum value detected by means of a temperature sensor associated with the collector channel. To ensure that on transition from the low-temperature reservoir operation to the high-temperature reservoir operation no heat transfer fluid having a lower temperature as compared to that of the fluid in the high-temperature reservoir can enter said hightemperature reservoir, the temperature of the heat transfer fluid as well as the temperature in the collector chamber is measured, both temperatures are compared so as to derive a temperature differential value, the control valve arrangement which is associated with a short-circuit branch running between the forward branch and the return branch is reversed dependent on whether a predetermined temperature differential value is reached so that the short-circuit branch is opened, the temperature of the heat transfer fluid in the collector channel as well as the temperature of the heat transfer fluid in the high-temperature reservoir is measured, both temperatures are compared so as to derive a temperature differential value and, finally, the control valve arrangement is reversed dependent on whether a predetermined temperature differential value is reached so that the short-circuit branch is closed but the connection to the high-temperature reservoir is opened.