A combined Dual Hot-Gas Bypass Defrosting method with accumulator heater for an air-to-air heat pump in cold region
A combined Dual Hot-Gas Bypass Defrosting method with accumulator heater for an air-to-air heat pump in cold region
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DOI：
10.1016/j.apenergy.2015.02.074
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发表时间：
2015-06
期刊：
影响因子：
11.2
通讯作者：
Jaehong Kim;Hwanjong Choi;K. Kim
中科院分区：
文献类型：
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作者：
Jaehong Kim;Hwanjong Choi;K. Kim
双热气旁通除霜（DHBD）循环是一种有效的除霜方法，与反向循环除霜（RCD）方法相比，可从空气热泵的室外换热器（HEX）中去除霜，特别是室外温度高于0 °C。然而，当热泵在低于0 °C的寒冷室外环境中操作时，由于制冷剂温度快速降低，随后是较低的热气旁通温度，DHBD方法具有缺点。为了克服压缩机排气温度低的问题，开发了一种DHBD与蓄热器加热方式相结合的联合循环。采用感应加热器（IH）作为蓄电池加热器。在室外温度为−5 °C的条件下，采用16 kW的中型空气-空气热泵，对传统RCD方法和DHBD-IH组合方法的动态性能和制冷时间进行了比较。由于增加了加热器，DHBD-IH组合方法比RCD方法在室内不间断供暖的情况下保持了较高的压缩机排气温度，并减少了15%的停机时间。DHBD-IH循环（包括双循环）的总制热量比RCD循环高2.5kW。
The Dual Hot-Gas Bypass Defrosting (DHBD) cycle is an effective defrosting method compared to a Reverse Cycle Defrosting (RCD) method to remove frost from the outdoor heat exchanger (HEX) of an air-to-air heat pump, especially the outdoor temperature is above 0 °C. However, the DHBD method has a drawback when the heat pump operates in cold outdoor environment, below 0 °C due to rapid decrease in refrigerant temperature followed by lower hot-gas bypass temperature. In order to overcome lower discharge temperature of compressor, a combined defrosting cycle with DHBD and the accumulator heating method is developed. An induction heater (IH) is adopted as the accumulator heater. The dynamic performance and defrosting time are compared between the conventional RCD method and the combined DHBD–IH method using a medium size air-to-air heat pump of 16 kW under the condition of −5 °C outdoor temperature. Due to the additional heater, the combined DHBD–IH method sustained higher discharge temperature of the compressor and reduced 15% of the defrosting time than that of the RCD method with nonstop indoor heating operation. The overall heating capacity of the DHBD–IH cycle including defrosting mode was 2.5 kW higher than that of the RCD cycle.