变流量空气源热泵集中供暖系统水泵及末端控制方法研究
Research on water pump and terminal control methods of centralized heating systems using variable-flow air-source heat pumps
摘要：
本文建立了变流量空气源热泵建筑供暖的数学模型，利用该模型研究了不同水泵控制方式下空气源热泵系统的性能。结果表明：为了使热泵机组保持较高的性能，其最小经济流量为额定流量的30%；3种控制方式中，供回水干管压差控制水泵功耗最大，最不利末端支路压差控制水泵功耗最小；相比于供回水干管压差控制，最不利末端支路压差控制水泵可节能0~31.84%；3种控制方式中，温差控制系统总功耗始终最大，最不利末端压差控制最小，它们的差值平均值在高负荷率下达到6.20%；压差控制和温差控制均可满足建筑供暖需要，但压差控制室内温度波动更小，适合用于对室内温度要求较高的场所。
Abstract：
In this paper, a mathematical model of the variable-flow air-source heat pump (ASHP) for building heating is established to study the ASHP system performance under different water pump control modes. The results show that in order to maintain the high performance of the heat pump unit, the minimum economic flow rate is 30% of the rated flow rate. Among the three control modes, the power consumption of the water pump controlled by the pressure difference of the main supply and return water pipe is the highest, and that of the most disadvantageous end branch is the lowest. Compared with the pressure difference control of the main supply and return water pipe, the most disadvantageous end branch pressure difference control pump can save energy by 0-31.84%. Among the three control modes, the total power consumption of the temperature difference control system is always the largest, the pressure difference control at the most disadvantageous end is the lowest, and the average value of their difference reaches 6.20% under the high load rate. Both pressure difference control and temperature difference control can meet the heating needs of buildings, but the room temperature fluctuation of the pressure difference control is smaller, so it is suitable for places with higher room temperature requirements.
Keywords:air-source heat pump; water pump; variable-flow system; control strategy; heating terminal; pressure difference control; temperature difference control