December 31, 2021
The invention relates to an air source heat pump defrosting start-up and stop control method, which comprises the following steps: Step 1: The air source heat pump unit starts up and operates to generate heat, the input Power P1, temperature value TL at the bottom coil of the outdoor air source heat pump unit and continuous heating operation time t of the air source heat pump unit were collected Step 2: Start defrosting after the following four conditions are met in turn: (1) the continuous heating operation time t of the air source heat pump unit exceeds the set time value t 1, if so, test the next condition; (2) the input power P1 of the air source heat pump unit system has reached the maximum PMAX, if so, test the next condition; (3) the temperature TL at the bottom coil of the air source heat pump outdoor unit is lower than the minimum value of the set temperature range T1, if so, (4) the input power p 1 of the air source heat pump system is lower than the set power P ′ , P ′ = (70% ? 80%) PMAX, if yes, start defrosting; step 3, when the defrosting condition is satisfied, the defrosting is finished.