초록 ▼

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photo voltaic (PV

A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photo voltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

대표청구항 ▼

[ What is claimed is:] [1.]1. A refrigeration system which comprises:an enclosure having an interior space;phase-change material situated in said interior space;a photovoltaic panel configured to provide electrical power having a DC voltage; anda compressor electrically connected to the photovoltaic

[ What is claimed is:] [1.]1. A refrigeration system which comprises:an enclosure having an interior space;phase-change material situated in said interior space;a photovoltaic panel configured to provide electrical power having a DC voltage; anda compressor electrically connected to the photovoltaic panel to receive electrical power at said DC voltage, wherein the compressor is configured to circulate refrigerant through a first heat exchanger to cool the refrigerant, through a constriction configured to sustain a pressure drop, and through a second heat exchanger to extract heat from said interior space.