The invention discloses a
compressed air energy storage system, which comprises a compressor unit, a pre-expansion device, a
turbine expansion
machine, an intermediate cooler, an
electric motor, a power generator, a
hot water storage tank and a cold
water storage tank, wherein the
system utilizes
electric energy which is not used up in the user
electricity consumption valley period or
wind power station power generation peak period for driving the compressor unit to work, the air at the normal pressure is compressed to
high pressure, in addition, the part of air with rich pressure energy is stored into a high-pressure-resistance hole, in addition, the stored high-pressure air is released in the user
electric consumption peak period or the
wind power field generation valley period, an expansion unit is pushed to apply work, and the
electric energy is output. The air pre-expansion device is additionally arranged at an outlet of an air storage chamber, so the air
inlet pressure of the air
turbine expansion
machine is stable, the work stability of a
power generation system is enhanced, low-temperature air at an outlet of the pre-expansion device is utilized for cooling hot water from the
hot water storage tank, the temperature of the low-temperature air is raised through absorption of heat from the hot water, and the cooled water enters the cold
water storage tank. The
compressed air energy storage system is provided with the
hot water storage tank and the cold
water storage tank, the water is cyclically utilized in a
closed loop, the water is not consumed, in addition, the heat discharged by the compressor is fully utilized and conveyed back to the high-pressure air at the outlet of the pre-expansion device. The high-pressure air at the outlet of the pre-expansion device is recovered through a heat recovering device (HRH).