摘要 |
A combined heating and cooling system includes a solar collector and evaporator for absorbing heat from solar radiation and/or the ambient air and for using the absorbed heat to evaporate a binary-phase, liquid-vapor working fluid. In the heating mode, whenever the temperature of the working fluid inside the evaporator of the solar collector is sufficiently higher than that of the medium to be heated, the working fluid follows a cycle similar to the Rankine cycle in which the heat engine is eliminated. Whenever the temperature of the working fluid inside the evaporator is no longer high enough for heat to be transferred unassisted to the medium to be heated, the working fluid is made to follow a heat-pump cycle. Finally, whenever the temperature of the working fluid in the evaporator falls below the temperature of the surrounding air, the evaporator is exposed to the ambient air and the system runs as an air-source heat pump. In the cooling mode, the system is run as a vapor-compression refrigeration cycle in which the compressor is selectively powered by the use of a solar-assisted Rankine power cycle. Means are also disclosed for cycle selection and control utilizing the equilibrium radiation temperature of the solar collector and evaporator.
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