CONTROL METHOD FOR HEAT-PUMP WATER HEATER, AND HEAT-PUMP WATER HEATER

摘要

A control method for a heat-pump water heater, comprising: a fitting calculation step, comprising (11) calculating energy efficiency ratios of a compressor monomer at different evaporation temperatures, condensation temperatures and compressor operating frequencies; (12) fitting an energy efficiency ratio formula; and (13) calculating a first-order derivative of the energy efficiency ratio formula, and obtaining an optimal operating frequency formula of the compressor by making an equation value of the first-order derivative be 0; and a starting operation step, comprising (21) periodically obtaining the evaporation temperature and the condensation temperature, calculating the optimal operating frequency of the compressor, and adjusting the compressor based on the optimal operating frequency.