Heat pipe vacuum tube solar hot water system work principle
 (1) heat pipe vacuum tube

 The structure of the vacuum tube as shown in Figure 1.  Sunlight through the glass tube in the heat radiation board, the sun will selectively absorb solar radiation film into heat.  Endothermic board will quickly absorb the heat in the heat of vaporization of a small number of workers, and quickly rose to condensation end, after the release of latent heat of vaporization condensed into a liquid, the role of gravity in the heat of evaporation downstream end.  Use a small amount of the heat pipe in the quality of steam - liquid cycle process can be changed continuously and will be delivered to absorb solar-heated water condensation.  For the heat pipe in the condensate after the return of the liquid-evaporation, heat pipe vacuum tube with the ground when the dip should be more than 10 °.

 Figure 1 structure of the heat pipe vacuum tube

 (2) heat pipe vacuum tube collector
 Figure 2 shows the heat pipe structure of vacuum tube collector. Visible from the plan, each heat pipe vacuum tube through the thermal conductivity of condensate-block heat will be transmitted to the set, which continuously heating water.  Vacuum tube and thermal conductivity of condensate-block rigid, was not heating water flows through the vacuum tube, so installation is very simple, even if the vacuum tube defects occur, the solar collector and the work will not be interrupted.

 Figure 2 heat pipe vacuum tube collector sketch

(3) heat pipe vacuum tube solar hot water system
 Figure 3 shows the heat pipe vacuum tube hot water system schematic. Heat pipe vacuum tube collector of solar radiation absorbed water heating and circulation pump storage tanks in the importation of low-temperature water collector for heating cycle. Working from the circulating pump-controlled instrument control, when the solar irradiance can not set value, the circulating pump is not working, if not set up to the day when the irradiance, the heating device may also be assisted heating.

 Figure 3 heat pipe vacuum tube hot water system schematics

 2 system in the main basis for the design of solar hot water system design must have some basic information as the basis for the design.
 (1) user requirements include: water, water temperature, time of the water requirements of whether or not to support heating, what supporting energy.
 (2) of the main buildings include: hot water system installed plane (roof) the specific size, roof load and load-bearing beam distribution, roof buildings there Zheng-nan direction of the shelter, water and power; allows users to provide roof Plane and structural drawings.

 3 solar hot water systems engineering parameters of (1) towards the system in the northern hemisphere, the collector arrays towards Zheng-nan.
 (2) collector area (a) in Beijing by heat pipe vacuum tube collector (in the sunshine 17000 KJ / m 2. D conditions), the collector surface per square metre (four heat pipe vacuum tube) from 9:00 to 15:00, the temperature set at 40-60 ℃, the production of hot water in spring and autumn 60-70 L / m 2. D, hot summer production of 70-80 L / m 2. D, producing hot water in winter 50-60 L / m 2. D.
 According to the actual needs of the user to select the average yield on the water.  If the system used throughout the year, especially in winter is to ensure that the water consumption, recommended to 50-60 L / m 2. D (water temperature above 40 ℃)-water standards to determine the collector area.
 (B) solar hot water system with hot water shower, water consumption Refer to the state has promulgated the "interior drainage water supply to the design specifications," the relevant provisions of the water temperature at 40 ℃ above, the average water consumption per person For the 35-40 L. Of course, the consumption of water to users based on the requirements of the final set.
 (3) If the collector system for the use of dip, dip recommended as the collector:
 α = local latitude + (5 ° -10 °)
 (4) before and after the row spacing collector to collector in order to not block each other, before and after the collector row spacing can be identified in Table 1.
 (5) Building roof to install solar hot water system load of the building roof, the live load requirements in more than 150 kg/m2.
 4 collector of the arrangement, water tanks and piping layout design (1) collector's collector arrangement of the arrangement of a series, and series-parallel hybrid, shown in Figure 4. Can be selected according to need.

 Figure 4 collector arrangement

 (2) the layout of water tanks

First, water tanks should be installed in the construction of the loading pier, if there is no basis for loading pier, it should be based on understanding of load-bearing structure of the building, loading pier will be placed in the load-bearing beam (wall). At the same time should also consider water supply and water pipes should be kept short, and water tanks closer to avoid the long line of the exposed and a Donglie.
 (3) the design of piping hot water circulation system of circulation line is the main circulating pump the water from the mouth of the collector set to return to the line of storage tanks.  In the circulation line of the highest-To set up a tracheotomy, the trachea should be put above the highest point of 600-800 mm, the entire line of a certain gradient (> 0.5 percent), the purpose of the circulating pump stopped running, So that the water pipeline can automatically return water tanks.
5 System Design

 (1) solar hot water system layout system layout shown in Figure 5.  One collector before and after the row spacing L can be identified in Table 1.

 Table 1

 Collector angle α  30° 30 °  40° 40 °  45° 45 ° 
 Pai collector before and after the interval L (mm)  1800－2000 1800-2000  2500－3000 2500-3000  3000－3200 3000-3200 

 Figure 5 system layout plans
n1, n2, n3 collector for the single-row (unit) number, L for the collector spacing between the single-row

 (2) system based design system based on the design shown in Figure 6.  The plan marked the major collector and water storage tanks based on the size and relative position.  If roof structure, these should be marked with the roof structure of the size of the location of the relevant benchmarks.

 Figure 6 system based on map

 Single-row basis of the pier horizontal distance of 2000 mm, single-row horizontal distance if the total length of 2000 mm instead of the whole several times, the last of basic pier between the horizontal distance should be within the 2000 mm, the size of its specific plans by the 6-L1, L2, L3 determine the size.  Based embedded board should conduct Chao-ping, its contours.
 (3) collector stent design is based on collector stent system in the layout of the collector and the number and arrangement of the collector inclination of the design.  Identify the main collector inclination of standard cell stent (tripod), through horizontal reinforcement spot welded together. Its single-ranked by the total length of single-row collector of identification, the overall stent horizontal inclination angle through the tripod for support under the regulation, to ensure that gradient> 0.5 percent.
 (4) the structural design of water tanks volume set: to control the ball valve floating below the water surface as the volume of water the size.  Water tanks in the pipe include: the circulation line of pipe connected to the water cycle (which even a circulating pump), the cycle back to water pipes, cold water on the water pipes, hot water from water pipes, water tanks Pai Wuguan, overflow pipe, installed probe The welding of the hoop, and so on.
 Water tanks in various parts of the relative position of the design should follow the principles of: (a) the system is running, hot water from the surface to a minimum, the circulating pump is always at the mouth of the water surface below the pump to work, not Let circulating pump idling; if electric heating, electric heating installation location should ensure that no Ganshao.  (b) the tube should ensure that the relatively high degree of vertical, horizontal position can be flexible arrangement.