Experimental performance evaluation of a novel heat pump water heater assisted with shower drain water

Since the temperature of shower drain water (SDW) is relatively high, lots of heat is wasted with the discharge of SDW. Therefore, the recovery of this unutilized heat from SDW shows great potential in improving the building energy efficiency. In this paper, a novel heat pump water heater assisted with SDW for small single family was proposed, which could effectively recover the energy in domestic SDW. To improve its performance, a shower waste heat extraction device (WHED) with water pre-heated loops was designed. A prototype of the system was firstly set up, and then the system performances under different conditions were experimented and discussed. The experimental results showed that approximately 70% of energy could be saved using this novel heat pump water heater, compared with the traditional electric water heater. Furthermore, the COP of the system could be improved observably when using water pre-heated loops. Thus the implementation of this novel heat pump water heater was verified to be capable of reducing energy usage and CO2 emissions significantly.

[1]  L. Wong,et al.  Shower water heat recovery in high-rise residential buildings of Hong Kong , 2010 .

[2]  Jong-Ho Yoon,et al.  A study on the design and analysis of a heat pump heating system using wastewater as a heat source , 2005 .

[3]  Deng Shiming,et al.  Experimental performance evaluation of a novel dry-expansion evaporator with defouling function in a wastewater source heat pump , 2012 .

[4]  Dawei Tang,et al.  Investigation on the thermal performance and optimization of a heat pump water heater assisted by shower waste water , 2013 .

[5]  Lin Fu,et al.  Study of the performance of an urban original source heat pump system , 2010 .

[6]  J. Claesson,et al.  Analyzing the efficiency of a heat pump assisted drain water heat recovery system that uses a vertical inline heat exchanger , 2014 .

[7]  Joseph C. Lam,et al.  Energy performance of air-to-water and water-to-water heat pumps in hotel applications , 2003 .

[8]  M. De Paepe,et al.  Heat recovery system for dishwashers , 2003 .

[9]  Aonghus McNabola,et al.  Efficient drain water heat recovery in horizontal domestic shower drains , 2013 .

[10]  Yiqiang Jiang,et al.  An experimental comparison of two heat exchangers used in wastewater source heat pump: A novel dry-expansion shell-and-tube evaporator versus a conventional immersed evaporator , 2012 .

[11]  Ali Kahraman,et al.  Investigation of the performance of a heat pump using waste water as a heat source. , 2009 .

[12]  Racine Tadeu Araújo Prado,et al.  Water heating through electric shower and energy demand , 1998 .

[13]  Hansjürg Leibundgut,et al.  The potential of wastewater heat and exergy: Decentralized high-temperature recovery with a heat pump , 2011 .

[14]  Wei Wu,et al.  Simulation of a combined heating, cooling and domestic hot water system based on ground source absorption heat pump , 2014 .

[15]  T. Kiatsiriroat,et al.  Performance analysis of solar water heater combined with heat pump using refrigerant mixture , 2009 .

[16]  Savvas A. Tassou.  Heat recovery from sewage effluent using heat pumps , 1988 .

[17]  Yi Jiang,et al.  Application of an exhaust heat recovery system for domestic hot water , 2010 .

[18]  Wenming Yang,et al.  Advances in heat pump systems: A review , 2010 .

[19]  Liangcheng Yang,et al.  An experimental and numerical study of a de-fouling evaporator used in a wastewater source heat pump , 2014 .

[20]  Constantinos A. Balaras,et al.  Potential for energy conservation in apartment buildings , 2000 .

[21]  Ruzhu Wang,et al.  Experimental performance analysis on a direct-expansion solar-assisted heat pump water heater , 2007 .

[22]  Jianghong Wu,et al.  Transient behavior and dynamic performance of cascade heat pump water heater with thermal storage system , 2012 .