A solar centralized hot water system with heat storage function

Abstract

The invention discloses a solar central water heating system with a heat accumulation function, which comprises a solar thermal collector array, a water tank, a collector circulating pump, a check valve, an electromagnetic valve and other parts. A heat accumulator filled with phase-change heat accumulation medium is arranged on the bottom in the water tank, and the interior of a heat accumulator core tube is a water passage. A heat accumulator water passage inlet is connected with the outlet of the solar thermal collector array, a heat accumulator outlet is directly open in the hot water storage tank, and the inlet of the solar thermal collector array is connected with the bottom of the hot water storage tank sequentially through the check valve and the collector circulating pump and connected with a tap water supply pipeline through the water-lifting electromagnetic valve. Both hot water heated by the solar thermal collectors and cold water replenished into the water tank first flow through the heat accumulator core tube and exchange heat with the heat accumulator. When the water temperature in the water tank is higher or lower than the phase change temperature of the heat accumulation medium in the heat accumulator, heat is released to the heat accumulator or heat is absorbed from the heat accumulator. By means of the heat absorption and release of the heat accumulator, energy consumption can be reduced, and solar radiation energy can be effectively utilized by the way of peak load shifting.

Description

technical field [0001] The invention relates to the field of centralized production and supply of domestic hot water by using solar energy, in particular to a solar centralized hot water system with heat storage function and its optimized working method. Background technique [0002] With the decline of traditional fossil energy such as oil, coal, and natural gas, and the increasingly serious environmental problems caused by the use of these fossil energy, the development of various clean energy and renewable energy utilization technologies has received more and more attention. Among them, the use of large-scale solar heat collectors on buildings to centrally supply domestic hot water to buildings is an effective means of utilizing renewable energy and has excellent environmental performance. With the adjustment of urban energy structure and the characteristics of urban buildings developing towards middle and high-rise buildings, the application of engineering-scale solar co...

AI Technical Summary

Problems solved by technology

[0003] In sunny and high temperature weather in summer, due to the high intensity of solar radiation, the amount of hot water produced by the system exceeds the user's demand, which will cause the water tank to be full of hot water, and the temperature of the hot water will become higher and higher, which will lead to the following problems : 1) The temperature of the water supply is too high (sometimes reaching 65-80°C), which may cause the user to accidentally burn; 2) The water temperature is too high to cause the non-metallic components (such as sealing rubber, etc.) in the water tank and all flow-through parts to accelerate Aging, thus shortening the life; 3) The high temperature of the water stored in the water tank will increase the heat loss to the environment, and a considerable part of the heat energy stored in the high-temperature hot water that cannot be used in one day will be lost during the next day's water use time. , if the next day is cloudy, the heat absorbed in the previous day cannot be retained to the maximum extent to alleviate the gap of solar energy absorption in the day

[0004] For the above problems, some systems adopt the method of enlarging the water tank to solve the safety and heat loss caused by the high temperature of the produced water and stored water, and enable the system to store excess solar radiation heat on sunny days, but this is often limited by the bearing capacity of the building floor limits

In fact, since the weight of the water tank is generally in the range of nearly ten tons to tens of tons, even if the size of the water tank is set according to the rated hot water demand of the user, it is often limited by the carrying capacity of the building and has to use a smaller water tank. Therefore, it is not ideal to solve the above problems by enlarging the water tank, or it is difficult to realize due to the bearing capacity of the building

Of course, there are also some systems that set the control logic to stop solar heat collection when the water tank is full and the temperature rises to a higher value (such as 70°C), which causes the solar energy utilization limit to not be maximized; and causes the collector The water in the collector is boiling, and the high temperature will cause the accelerated aging of the non-metallic seals in the collector. If it is a vacuum tube collector, it may also cause the vacuum glass tube to burst when the water enters next time.

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