Direct expansion solar collector-heat pump system

摘要

A solar collector-heat pump heating system which comprises metallic plates which are directly exposed to the ambient atmosphere and which are in direct heat exchange relation with tubes. A compressor receives a heated low-boiling working fluid, e.g., R-22, from the tubes as a vapor, compresses it and delivers it to a condenser. The fluid then passes through a throttling valve where it partially vaporizes, then to the tubes, where vaporization continues, utilizing heat absorbed by the plates from solar radiation, the ambient air, rain, and long-wave infrared radiation. Heat is extracted from the condenser and used for space heating. Preferably, heat storage means, e.g., a tank of water or a body of low-melting salt, are provided. Preferably, the heat-absorbing plates are long and narrow. In one embodiment they are spaced from a diffuse reflective backing and are laterally spaced from each other. In another embodiment they form a siding for a building. When heat storage is provided, the system can also serve for cooling by reversing the flow of the working fluid and rejecting heat through the plates at night.