| 摘要 |
The invention is a solar energy conversion apparatus in which several evacuated, glass tubular collectors are connected together in a liquid circulation system for controlled movement of a liquid between the interior of the collectors and a storage tank. Liquid circulation is controlled by sensors and switches therefor in regulating operation of valves and/or a pump. The conditions for circulating the liquid rely upon (1) sensing a need for energy at the storage tank, (2) sensing solar radiation availability, (3) sensing thermal conditions in the solar collector tubes to avoid high temperature and thermal shock, and sensing a need to withdraw hot liquid and add more. The system is operable in either of two modes herein disclosed: (a) the "continuous batch circulation" mode in which liquid is pumped to fill the tubes, in parallel, and low temperature sensed below a set point to stop pumping and resume pumping when the temperature in the tubes arrives at the preselected higher temperature, and (b) the "full continuous circulation" mode in which liquid is continuously pumped through the tube collectors, in parallel, continuously withdrawing liquid from the top of the tube while introducing liquid at the bottom of the tube; in either mode, the hotter liquid being removed from the top of the tubes and relatively colder liquid introduced at the bottom of the tubes. The invention includes a full drainability of all the tubes of the system under control when conditions are sensed to call for draining the tubes; such as, the end of the solar day, the storage tank temperature exceeds a certain value (enough energy is stored), or tube temperature is too high; and, restarting of circulation of liquid to the tubes is abated until their temperature is within preselected operating range. The system will operate using water without additives without danger of freeze up and all collected energy is placed in storage at the end of a solar day period. The system includes a second circulation system through the storage tank to remove the heat in utilizing it, such as in a domestic hot water system. This second system removes water to be heated from the base of its hot water tank and pumps it through a heat exchanger in the solar heated liquid tank and back to the top of the hot water tank. |
