According to the hot and cold water circulation principle of solar engineering heat collection modules, it is the theoretical basis for the design of solar engineering collectors. According to the role of solar engineering collectors in solar engineering, they are the exchange of cold and hot water. An important task is containers, which improve the heat exchange efficiency of solar engineering collectors. Firstly, reduce the collector capacity of the solar project so that the cold water can gain high-frequency potential energy and accelerate the frequency of hot and cold water exchange. The second is to improve the thermal insulation effect of solar engineering collectors and reduce heat loss. Third, the design requirements of the collector water inlet and outlet of the solar power project must overcome the air blocking phenomenon, 1; improve speedse of hot and cold water exchange in the collector of the solar project in series, 2; stability of water movement. Jiayou Sunshine designs, processes and organizes the production of solar engineering collectors based on this guiding ideology.
What is the difference between solar water heaters and solar collectors?
Collector connection methods are divided into three types: parallel connection, series connection and series-parallel connection.
(1) Parallel connection
Connect the inputs of multiple collectors to the inputs and the outputs to the outputs. For example: connect the upper and lower ports of one end of the flat collector to the upper and lower ports of another collector, and the upper and lower ports of this collector are connected to the upper and lower ports of the third collector. Leave a port on each of the first and last collectors after connectionn parallel. Leave a port on one end and a port on the other end to form a diagonal path. The number of parallel flat sensors in each row should not exceed 16. For heat pipe sensors, U-tube sensors and horizontal tube sensors, parallel connection means connecting their water inlets to their water inlets. water and their water outlets at their water outlets.
When connected in parallel, the flow is superimposed and the pressure drop remains unchanged, which can reduce the pump height. As long as the flow through each collector is uniform, the thermal efficiency of the parallel connection. This is better, so in the collector group, the collectors should be connected in parallel as much as possible.
There are three methods to standardize the flow:
1. Reversible return pipe connection (connection in the same direction)
Keep the flow rate of each collector equal., the reversible return pipe connection shown in the figure requires additional pipes, but the flow through the collector is uniform because the flow rate is the same for each collector.
2. Balancing valve connection (remote connection)
For off-remote connection (direct return), a system can be installed in each parallel sensor group to ensure uniform flow balancing valve , but this adds cost.
3. Change tube diameter
For large arrays of sensors connected at different distances, it is sometimes more beneficial to change the collector diameter to maintain a constant flow rate, but this requires precise calculation.
Connect the output of one collector to the input of another collector, and the output of this collector to the input of the third collector. The number of serial connections should be as small as possible. When the sensors inserted horizontallyent are arranged in several layers on the same slope, the number of sensors connected in series should not exceed 3 (the length of each collector should not exceed 2 m). ). The flow resistance of flat collectors is relatively large. Generally, flat plate collectors are not directly connected in series, but flat plate collectors are connected in series. Plate collectors are connected in parallel to form a group and then connected in series.
When connected in series, the pressure drops are superimposed, the flow rate remains unchanged, and a higher water outlet temperature can be achieved quickly. However, when connected in series, the average operating temperature is higher, thermal efficiency is reduced, pressure drop across the network is higher, and it is difficult to drain the sensor network. At the same time, a collector will be damaged. a group of collectors in serie can no longer work.
(3) Series and parallel connection
1. First connect the collectors in series or parallel to form a group, then connect the collector groups in series, in parallel, first in series. then in parallel, or Connect first in parallel then in series.
2. It is recommended to use a same direction connection between each group of collectors. That is, the length of the heat transfer fluid inlet path and return path of each group of sensors must be the same so that the flow is uniformly distributed. When the groups of sensors are connected at different distances, the flow rate of the collectors close to the inlet of the heat transfer fluid will be greater, while the flow rate of the collectors far from the inlet will be lower, resulting in a decrease in the system performance. Due to installation site restrictions, when remote connections must beused, a balancing valve must be added to the bypass of each sensor group to adjust the flow balance. The natural circulation system has a self-adjusting function and can be connected at different distances.
The same path and different path are distinguished based on the direction of water flow. The same path means that the distance traveled by all equipment from the water inlet to the water return is the same. The water flow in the main supply and return pipes of the same system flows in the same direction, and the total lengths of the supply and return pipe sections of two or more water supply loops are basically equal. Generally, the co-pass arrangement is adopted for hydraulic balance purposes. However, it is common to use the same process and different processes simultaneously. Laying pipes in the same processus aims for hydraulic balance, and the quantity of consumables is important! Although it is difficult to achieve hydraulic balance with remote hydraulic power, the amount of consumables is small! If the distance pipe design is reasonable, hydraulic balance can also be achieved.
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3. The number of collectors in a natural circulation system should not exceed 24. A large-area natural circulation system can be divided into several subsystems, and heat collection in each subsystem, the number of devices does not must not exceed 24.
(4) Selection of the collector connection method
The choice of the collector connection method depends on the one hand on the operating mode of the system and secondly the environment of the installation site. Reasonable connection methods can improve system efficiency and reduce manufacturing costs.
01. For natural circulation systems, collectors should be connected in parallel with low resistance. The number of parallel collectors in each row should not exceed 16; the total number of collectors in each system should not exceed 24. A natural circulation system over a large area can be divided into several subsystems. 02. When horizontal intubation collectors are arranged in several layers on the same slope, the number of collectors connected in series should not exceed 3, and the length of each collector should not exceed 2 meters.
03. For forced circulation systems, collectors can be connected in parallel, series and series-parallel combinations. The number of parallel or series collectors in each group should not exceed 16. When the number of collectors exceeds 16, this can be achieved by connecting the collectors in series and parallel.
04. The connections between each collector group must be When using the same path connection, when using a different path connection, a balancing valve must be added to the branch of each collector group to adjust flow balance.
05. When collectors are connected in parallel, the number of parallel collectors in each group must be the same. I hope this helps you.
Most solar water heaters refer to the stand-alone solar version, which is for home use and can be used directly by pressing it. The solar collector refers to the collector for technical use, which is intended for technical use. should also be equipped with insulated barrel and vacuum tube, water pipes, temperature measuring devices, etc. can be used together in hotels, guesthouses, hospitals, schools, etc. I hope thatit helps you. .