Optimal Performance of Solar Heating System
Abstract
Forced-circulation solar heating system has been widely used in process and domestic heating applications. Additional pumping power during the solar energy absorption is required to circulate the working fluid through the collector banks to absorb the solar heat. The solar heat absorbed increases with increasing flow rate as well as pumping power. A lot of solar heat systems were usually designed to operate at a flow rate given by the assigned flowrate of collector test standards, 0.02 kg m-2 s-1, which may be over-estimated and causes large pumping power consumption. Many researchers intended to develop an optimal control technique to reduce the pumping power at optimal solar heat collection [1-4] such as using exergy concept [2] or system optimization method [4]. The control algorithms however were very complicated and not easy to be implemented in field. In addition, no feedback control scheme was ever been applied to assure the optimal performance under variable solar radiation. In the present study, we intend to develop the technology maximum-power-point tracking control (MPPT) similar to MPPT of solar PV system and implement it in a solar heating system for field test.