Series-parallel solar hot water project is generally on a small scale between domestic solar water heaters and hot water project of union module. Because the technical requirements of the less difficult over the years and did not arouse enough attention to most of the engineering design and installation is not very scientific and standardized, resulting in many of these works, there are many defects, affecting the engineering effects of play on the objective. In recent years, with increased awareness of solar water heaters, hot water project has been more attention. From the economic point of view, if a small series of parallel tube compared to the union has a strong competitive, technically, is not existing engineering union tube. As the series-parallel type with low cost, simple control run, applicability, rely on the natural cycle has been widely popular. Series and parallel technology is relatively easy for most distributors. Leave such an objective to give such works a certain market space. Nevertheless, if you want to design and installation of some of the practical problems of series and parallel hot water works or should pay sufficient attention. I installed according to recent practice, as summarized below for reference.
A series-parallel hot water project should not be too much. By the non-confined home water heaters, stand-alone series and parallel group, I think that each group a water capacity of not more than 7-8 tons as well, stand-alone water capacity should be as large as possible, thus reducing installation costs, reducing the surface heat volume, low cost. If the situation requires the amount of water can be considered the total water use will be divided into several groups, each group group to form a separate system, more than one group into an integrated whole system. This design has the following advantages: each packet group level degree is easy to adjust; a single water heater bombing does not affect the other group; were split into periods, respectively, electricity or other energy auxiliary heating to reduce the heating power; simultaneously or alternately water to extend the water supply hours.
Second, adjust the level between the same group. Flat-topped or sloping roofs house, do the series and parallel water works should first adjust the group level degree, it is best to ensure that the height difference of the overall level of 20 mm, if the site is measuring the level of instruments available for some transparent plastic tube filled with water instead of a level, the actual effect is very good. Should also identify the level to find a good group toward the pumping device group, and a single water heater, the orientation of the group subject to many constraints, not easy to adjust, just south west goal.
Third, the connection mode to optimize. Each group a single number without too much of the pipeline connected to the best in parallel with little or no in series form, maintenance intervals can leave enough between Taiwan and Taiwan. So that the flow resistance equalization and the minimum. Row of solar water heaters parallel, as far as possible they would not block or less obscured, in order to reduce the front and rear stand light, choose the height of a slightly lower solar water heater is more favorable.
Pipeline design and installation. If the project request water supply volume, long time, high frequency, independent access to water down the water. Into the water on the road, if the water pressure is too application valves restrict the flow, velocity, and to ensure that the group of solar water heaters each have balanced the Sheung Shui to avoid Sheung Shui fast or slow water level is not balanced. If the water pressure is too low you should install a booster pump water supply and Sheung Shui solenoid valve synchronization can be run.
Fifth, the hot water pipeline design and installation. General water supply pipes are made of natural drop water, when the return pressure less than 0.5kg/cm2 hot water booster pump should be installed, should be considered in the system water capacity, water points, the number of water flow, the flow rate to determine the water supply pipe diameter size is too thick is a waste of materials, too small to inadequate flow of bath spray ineffective. If the water supply pipe is too long in cold water too much, can also be designed into the piping of the circulatory system, and an instant hot The actual operation of the Sheung Shui supercharger, water pressure, the completion of the pipeline loop three systems with a pump, a small increase in the point of attachment can achieve their goals.
Six primary and secondary piping material selection. Down the water main channel materials selection PPR were more likely to practice has proved, it has economic, frost resistance, and easy construction insulation effect, non-corrosive, health, neat appearance, Annex low price. In pipeline design, part of the Sheung Shui to have the valve, filter valve, solenoid valve, check valve and so on. The water supply part of the trunk, the branch shall be fitted with valves to maintenance.
Seven, intelligent control systems are advanced. General, regardless of the size of the project should be supporting the series and parallel engineering control cabinet system. Implementation of intelligent control, automatic unattended due to general engineering water with high requirements, it is necessary to save energy and require a long time more available hot water, so in the limited investment in fixed capacity case, the configuration of a fixed temperature, Sheung Shui, control cabinet wise, and the general price is not high.
If the electric auxiliary heating, in principle, three more than the water heater on the application of three-phase power supply, and the star connection. Each group in series works only representative in the tank placement of a water level probe. The highest water level of the probe should be less than this group of tank overflow pipe to the lowest point. In addition, the intelligent control system should also have thermal overload protection, overcurrent protection, leakage protection. Particularly worth mentioning is in the northern alpine region, the bombing of the protection without running water may appear to be particularly important, especially works the greater.
Eight, pay attention to safety issues. Even if the system has pipe freezing cycle function best in the northern regions should be configured band thaw system, just in case. System lightning protection and grounding, lightning rod should be set to follow department requirements. The entire hot water system to have a good grounding of the electrical part.