Energy Saving and Economic Evaluations of Exhaust Waste Heat Recovery Hot Water Supply System for Resort

Abstract

The objective of this study is to investigate the energy savings and economics of the hot water supply system for the luxury resort. The hot water was generated using the waste heat from the exhaust gas heat (EGH) of internal combustion engine (ICE) installed at the luxury resort. The capacity and characteristics of waste heat source, flow demand and supply system of hot water were surveyed, and data is collected from the real system. The new heat exchanger system which utilizes the EGH to produce the hot water is designed considering the dew point temperature and the back pressure of exhaust gas system. The results show that the proposed system could supply hot water at a temperature of 55 °C corresponding to the present resort demand of 6 m3/h using EGH of ICE at 20% load. The proposed system could achieve the saving of 400 L/day in diesel oil (DO) fuel consumption and the payback time of new system could be evaluated as 9 months. The proposed system could produce hot water of 14 m3/h at 25% of engine load and 29 m3/h at full engine load which are sufficient to satisfy the regular and maximum hot water demand of resort. The presented results show the capability of the proposed system to satisfy the current hot water demand of resort and suggest the larger potential to save energy by recovering EGH of ICE. The novelty of the present work involves detailed methodology to design heat exchangers and evaluate system economics for hot water supply system based on EGH of ICE.

Opportunities of waste heat recovery from various sources: Review of technologies and implementation

“…The continuous combustion of fossil fuels to meet this energy demand has continued to cause progressive destruction of the environment through Greenhouse Gas (GHG) emissions. Numerous strides have been made toward minimizing the quantity of heat discarded into the environment, to reduce the carbon footprint and improve process economics [ 2 , 3 ]. To reduce excessive dependence on the use of fossil fuels to attenuate the impact of associated environmental pollutants, Woolley et al [ 4 ] suggested that manufacturers should give priority to both renewable energy systems and WHR technologies.…”

“…There are hotels, resorts, and motels rendering services to tourists and travellers, which are strategically sited in remotely quiet and clean environments such as forests, islands, and coastlines that are far away from the power grids. To keep the guests comfortable, there is a need to meet their usual demands such as the provision of electricity and hot water, and ICEs are mainly used to actualize such [ 3 ]. For business owners to reduce operation costs due to excessive fuel consumption and at the same time help to minimize environmental footprint, WHR techniques are a viable option.…”