Views:3 Author:Site Editor Publish Time: 2018-08-07 Origin:Site
With the acceleration of the integration of solar energy applications and buildings across the country, various renewable energy technologies that are suitable for the resource conditions and building utilization conditions of the region are promoted. The enthusiasm of local governments, developers, and solar energy companies has been greatly promoted, and a number of large-scale projects have been implemented one after another. In particular, high-rise residential buildings in real estate use balcony wall-mounted solar water heating systems, which have been widely used as the main source of hot water. use. A set of efficient, safe and reliable hot water systems not only requires high-efficiency solar collector technology as a support, but also heat storage equipment requiring efficient heat transfer as a guarantee of quality and quality. Because the balcony wall-mounted solar water heating system is limited by certain conditions in the middle and high-rise building applications, in order to improve the energy efficiency rating index of the balcony wall-mounted solar water heating system, this requires the storage of the balcony wall-mounted solar water heating system. In addition to the heat storage function, the thermal equipment should have a high-efficiency heat transfer function to convert solar energy into heat energy for maximum storage. Through the research and analysis of the way to influence the heat transfer effect, the new energy storage dual-core stainless steel pressurized water tank made by changing the structural design of the water tank heat exchange layer www.csbwsx.com, the heat exchange efficiency is higher than that of the ordinary hot water tank used in the market. Increased by 26%, and improved the energy efficiency index of the balcony wall-mounted solar water heating system by 10%, creating a huge development space for the application of the balcony wall-mounted solar water heating system in the middle and high-rise buildings.
1. Heat transfer efficiency is the core idea of the design of accumulating dual-core stainless steel pressurized water tank
At present, the heat exchange process of the solar water heating system of the balcony wall-mounted solar water heating system is basically a non-phase-changing convective heat transfer process, that is, when the high-temperature fluid that absorbs solar heat flows through the surface of the heat exchange solid, due to the two The transfer of heat occurs at different temperatures, during which the fluid does not undergo a phase change (condensation and boiling), but a single-phase fluid. According to the basic calculation formula of Newtonian cooling φ=h×A×Δt, it can be known that increasing the heat exchange area A, increasing the heat transfer temperature difference Δt between the fluid and the wall surface, and increasing the surface heat transfer coefficient h all have the effect of enhancing heat transfer. In the process of enhancing heat transfer, increasing the heat transfer area A and increasing the heat transfer temperature difference Δt between the fluid and the wall surface is relatively easy to determine, while the surface heat transfer coefficient h value reflecting the heat transfer strength is affected by various The influence of factors is difficult to determine.
The core idea of the energy storage dual-core stainless steel pressurized water tank is how to greatly improve the heat exchange efficiency. In the design process of energy storage dual-core stainless steel pressurized water tank, the idea of strengthening the heat transfer of the water tank is always adhered to. By increasing the heat exchange area A as much as possible, increasing the heat transfer temperature difference Δt between the fluid and the heat exchange surface, and increasing the surface heat transfer coefficient h Such measures to enhance heat transfer to achieve a significant increase in water tank heat transfer efficiency.
The energy storage dual-core stainless steel pressurized water tank is mainly composed of a heat storage inner tank (1), a heat collecting inner tank (2) welded to the outer wall of the heat storage inner tank, and a heat exchange circulation pipe inlet and outlet interface (5) ( 6), cold and hot water layered into the water pipe interface (8), water tank insulation layer, water tank liner, electric auxiliary heating and control accessories. The laminated jacket double core liner is used on the water tank structure. In the design, the heat storage surface of the energy storage dual-core stainless steel pressurized water tank is rolled from a smooth surface into a spiral rising groove heat exchange surface (4), which not only expands the whole The heat exchange area of the water tank is 35%. At the same time, due to the change of the shape, size and position of the heat transfer surface, the spiral rising groove heat exchange surface in the heat exchange process will continuously change the direction during the forward movement, in the cross section. Causes secondary circulation, which can generate turbulence at a lower Reynolds number, which enhances heat transfer.
At the same time, the accumulating dual-core stainless steel pressurized water tank collector tank is designed as a narrow heat exchange space. On the one hand, under a certain ratio of heat transfer path and small flow constant pressure condition, the fluid can maintain a good flow rate and achieve high heat transfer. Efficiency; on the other hand, the fluid layer can be thinned during the heat exchange process, and the heat transfer coefficient is further increased.
Because the liquid flow direction of the water tank in the water tank is heated from bottom to top, the water tank heat exchange inlet and outlet pipes are designed to be 180 degree countercurrent circulation heat exchange mode, and the hot fluid medium flows in from the upper part of the heat exchange wall, after 180 degree heat exchange. The channel is then discharged from the lower part of the heat exchange wall. Under the same fluid inlet and outlet temperature, the average temperature difference between the hot and cold fluid is the largest, which enhances the heat transfer.
Through the above different ways and methods for the design change of the water tank heat transfer structure, the overall heat exchange effect of the water tank can be greatly improved by 26%, highlighting the energy efficiency of the energy storage dual-core stainless steel pressurized water tank.