Improving the efficiency of energy recovery from wastewater by using a double heat exchanger to protect the environment

A possible strategy for reducing energy consumption and carbon dioxide emissions in order to protect the environment is the recovery of heat from wastewater. This study aims to achieve an improvement in the effectiveness of heat transfer by changing the flow parameters by using a double heat exchanger to recover the heat from greywater. The results, the thermal energy from wastewater can be recovered, the effectiveness ranged between (25 % — 45 %) with the discharge of (0.15-0.51m3/h) lower to higher, respectively. The cold water flow has a clear effect on the heat transfer efficiency, the decrease in cold water velocity led to the increase in heat transfer performance. This technique is simple to implement and inexpensive. It can be designed and built on the basement of the multi-storey building. The dual heat exchanger splits the flow into two-pipe, decreasing the flow rate velocity and thus, increasing the heat transfer efficiency.