Research On Structural Improvement Of Pressure-bearing Integrated Solar Water Heating System

At present,China has become the world’s largest production and sales of solar water heaters.According to the statistics made by "China Energy Conservation Association solar Specialized Committee",the total number of new solar collectors in 2018 was 35.43 million square meters,down 4.9 percent from the same period last year.Total market ownership continued to grow to 482 million square meters,up 1.0 percent from the same period last year.But sales of household solar hot water systems fell significantly in 2017,when the retail market for solar water heaters in China fell to 27 percent from 50 percent in 2015.The application of solar water heater is gradually transitioning from the open type solar water heater with the simplest natural drop water supply to the intelligent product with more intelligent control and can be operated under pressure.Therefore,actively carry out technological innovation,improve the thermal performance of the system,continuously reduce the production and manufacturing costs,production and marketing can supply hot water 24 hours a day,The pressure-bearing solar hot water system with higher cost-performance ratio is the future development direction of domestic solar water heater in our country.The target product of this subject is the pressure-bearing integrated solar hot water system,which is divided into a new type of pressure-bearing solar hot water system and an automatic pressurization water supply system.This paper summarizes the design scheme and development trend of domestic solar hot water system,compares the advantages and disadvantages of the existing closed system,uses Por/E to carry out 3D modeling and assembly,and designs and optimizes the structure of enclosed inner tank and heat transfer pipe.The system structure of split pressure or indirect heat transfer is designed as one-piece direct heat transfer structure.At the same time,the thermal performance of the system is tested by the testing platform of CNAS laboratory,and the product structure is optimized.Aiming at the problem of low service life caused by the stress corrosion phenomenon and the water hammer effect of the inner container,the automatic booster water supply device is designed,the three-dimensional modeling and assembly of the Por/E software are carried out,the design parameters are optimized,and the production of the sample is finished by using the 3d printing technology in the test stage,The experiment verifies the reliability of the control,the use of the device can greatly reduce the pressure and the pressure bearing time of the water tank,effectively avoid the stress corrosion cracking,prolong the service life,the inner container material can be reduced and the cost is savedIn this paper,the corrosion of aluminum alloy in NaCl medium with various corrosion inhibitors was studied by soaking corrosion test at high temperature.The corrosion inhibitor with good corrosion inhibition effect on aluminum alloy was selected,and the composite corrosion inhibitor with synergistic effect was prepared.It is used in the surface treatment of aluminum alloy heat transfer pipe,which provides a feasible technology and process for aluminum alloy to replace stainless steel as heat transfer pipeThis product is mainly used to meet the demand of hot water and heating for urban housing,rural housing,hotels,mining enterprises and institutions,barracks,etc.The implementation of this subject accords with the industrial policy of further expansion of solar energy thermal utilization and the requirements of energy saving and emission reduction,and has great promotion and application value.