Experiment Study on the Exhaust-Gas Heat Exchanger for Small and Medium-Sized Marine Diesel Engine

This paper aims to design a special exchanger to recover the exhaust gas heat of marine diesel engines used in small and medium-sized fishing vessels,which can then be used to heat water up to 55°C–85°C for membrane desalination devices to produce fresh water.A new exhaust-gas heat exchanger of fins and tube,with a reinforced heat transfer tube section,unequal spacing fins,a mixing zone between the fin groups and four routes tube bundle,was designed.Numerical simulations were also used to provide reference information for structural design.Experiments were carried out for exhaust gas waste heat recovery from a marine diesel engine in an engine test bench utilizing the heat exchanger.The experimental results show that the difference between heat absorption by water and heat reduction of exhaust gas is less than 6.5%.After the water flow rate was adjusted,the exhaust gas waste heat recovery efficiency was higher than 70%,and the exhaust-gas heat exchanger’s outlet water temperature was 55°C–85°C at different engine loads.This means that the heat recovery from the exhaust gas of a marine diesel engine meets the requirement to drive a membrane desalination device to produce fresh water for fishers working in small and medium-sized fishing vessels.

A Brief Discussion on Prefabricated Dishes Based on Unmanned Feed Cooking Technology

In order to meet the demand for convenient and fast food in modern fast-paced life,the demand for pre made dishes is increasing day by day.The unmanned feeding and cooking technology relies on automated and intelligent equipment to control the entire cooking process through preset programs and prepare pre made dishes.Prefabricated dishes based on unmanned feeding and cooking technology are a product of the combination of modern food industry and high-tech,which has brought revolutionary influence to traditional cooking and dish production.The unmanned feeding and cooking technology greatly improves the production scale and efficiency of prefabricated dishes through automation technology,and ensures the consistency of food quality,taste,and hygiene through preset programs and automated operations.The unmanned feeding and cooking technology even improves the efficiency of the entire industry chain through full process automation and intelligent management,promoting the upgrading and development of the prefabricated food industry.