| In recent years,with the development of the dual carbon policy and the deepening of energy shortages,more and more attention is paid to the topic of energy consumption.At the same time,it is necessary to pay attention to the use of waste heat from the use of resources together with the active development of new energy sources,of which the highest recovery quality,the greatest efficiency and the easiest recovery is the waste heat recovery of bathing wastewater,and at present,there are more domestic and foreign studies on large bathing wastewater waste heat recovery systems,However,most of them are still in the theoretical research stage,and large systems recover waste heat from all areas together,and the quality of recovered waste heat is low,therefore,the article proposes a waste heat recovery system from wastewater from a small bath.The advantage of this system is that it can be recycled nearby,improve the efficiency of waste heat recovery,solving the problem of low quality of waste heat recovery in large systems,The system covers a small area and is placed directly in the bathroom.Based on theoretical calculation and literature research,a small bath wastewater waste heat recovery system is proposed.The system extracts waste heat from bathing wastewater through two stages of wastewater heat exchanger and wastewater source heat pump,and sets up heat storage tank at the same time,so that the waste heat from bathing wastewater can be eaten up and fully utilized by optimizing each component.The system mainly consists of three components: a wastewater heat pump,a wastewater heat exchanger and a heat accumulator,In this study,the structure of the wastewater heat exchanger and heat storage tank are optimized to further improve the waste heat recovery rate and the efficiency of hot water use,thus improving the performance of the whole system.Because the heat exchanger and heat storage tank were optimized by experimental methods and simulation methods,respectively,the heat exchange efficiency of the waste water exchanger was increased by 75%,so the hot water storage efficiency was 84.9%,which is 8% higher than the hot water production rate of better layered heat storage on the market.The heat input of the selected waste water heat pump for the system was calculated at 11.64 k W,the optimized device was connected according to the system diagram and experimental tests were performed and the COP of the system was up to 5.9.TRNSYS software was used to model the system and the simulation results were compared to experimental results to verify the realism of the simulation.The annual simulation results were analyzed,and the analysis found that the annual cumulative heat supply of the sewage heat pump unit was 22837.91 k Wh,the annual cumulative heat recovery of the sewage heat exchanger was 8645.8k Wh,and the annual power consumption of the heat pump was 5476 k Wh and the heat pump average COP is 4.2and the average COP of the system is 5.8,which means good efficiency.If you compare the annual value of the acquisition cost method,the economic efficiency of using waste heat in a pool with a life cycle of 15 years is better than a central hot water system in the pool without using waste heat. |
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