为解决能源浪费的问题,通过引入相关结霜模型进行理论分析,结合实验数据得出“理论最佳除霜量”的半经验公式。为验证该公式有效性,针对某厂家的补气增焓准二级压缩空气源热泵进行不同工况下：空气相对湿度65%、70%、80%,对应的空气干球温度-4~4 ℃的温度区间的实验测试。通过测试不同状态下的实际除霜量与“理论最佳除霜量”的半经验公式计算的理论除霜量进行比较,发现两者相对误差较小,保持在±10%以内,该公式对霜层后期的预测值较为准确,可作为设计补气增焓准二级压缩能够空气源热泵融霜时间控制的基准。
Abstract
To address this energy waste, this paper conducts a theoretical analysis by introducing relevant frost formation models and combines experimental data to derive a semiempirical formula for the "theoretically optimal defrosting amount". The formula mainly involves parameters such as cold surface temperature, moisture content of saturated water vapour, time, and wind speed. Moreover, this paper explains why defrosting does not occur during the early stage of frost formation and highlights that this factor has a relatively minor impact on the overall predictive performance. To verify the effectiveness of the formula, this paper conducted experiments on a manufacturer's supplemental gas enthalpy booster-type secondary compression air-source heat pump under various operating conditions. Experimental tests were conducted in a temperature range of -4 ℃ to 4 ℃ at relative humidity levels of 65%, 70%, and 80%. The actual defrosting amount observed under different conditions was compared with the "theoretically optimal defrosting amount" calculated using a semiempirical formula, and it was found that the relative error between the two was relatively small, within ±10%. The study showed that the formula provided a relatively accurate prediction of the frost amount in the later period of frost formation, and it could serve as a reference for designing supplemental heating control and secondary compressor enthalpy for controlling the defrosting time of air-source heat pumps.
关键词
空气源热泵 /
补气增焓 /
除霜 /
传热特性 /
最佳除霜量 /
结霜模型
Key words
air source heat pumps /
vapor injection /
defrost /
heat transfer characteristics /
optimal amount of defrosting /
frost model
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