Heat pump coupling contraflow type liquid-desiccant central ventilation system and control method thereof

A heat pump coupling contraflow type liquid-desiccant central ventilation system and control method thereof comprise a heat pump system and a liquid-desiccant and fresh air regeneration processing system, wherein the heat pump system comprises a compressor, a four-way directional control valve, a condenser, an evaporator and a throttle member; the liquid-desiccant and fresh air regeneration processing system comprises a fresh air processing module, a liquid regeneration module, a heat exchanger and a liquid pump; both the fresh air processing module and the liquid regeneration module are serially connected with the pipes by the two liquid heat exchangers through a liquid pool. The fresh air processing module is arranged in an indoor air inlet; the liquid regeneration module is arranged in an indoor air outlet to recycle the energy of the indoor exhaust wind. The invention adopts liquid-desiccant to process the fresh air of the air conditioner and removes the dust and the bacteria in the air through spraying the liquid so as to purify the air. The system can recycle the energy of the indoor exhaust wind, which reduces the energy for processing the fresh air; the heat pump is used for providing energy for the liquid to make use of the low-grade heat source.