Introduction
Solar thermal technology as a renewable energy source is an important way to implement the strategy of “energy saving and consumption reduction” in China. In recent years, the installation of solar water heating system in construction projects often forms its own system and is installed as a rear device of the building, which causes the solar water heater to be arranged on the building in an extremely unreasonable manner, and its fixation, wind protection, lightning protection and other security measures are not guaranteed, which also brings extremely adverse effects to the urban landscape and the safe use of the building.
In order to make the solar water heating system safe, reliable, stable performance, and harmonization with the building and the surrounding environment, it is necessary to promote the integration of building solar construction. The so-called building solar integration construction, is the solar energy products and components and building synchronous design, synchronous construction, synchronous acceptance; and to achieve organic combination with the building.
Xingtai City, Hebei Province is located in the southern part of Hebei Province, with 2800 hours of sunshine and annual solar radiation greater than 3500 megajoules / square meter, one of the more abundant solar energy resources. As far back as the 70s citizens began to install many forms of solar water heaters.
At present, there are more than 20 solar water heater manufacturers, with an annual output of 180,000 m2 of solar collector area, which can meet the needs of 12 million m2 of civil buildings. The local Hebei Jinglong Group is the world’s largest monocrystalline silicon production base, recognized by the Ministry of Science and Technology as the “National Torch Plan Ningjin Solar Silicon Material Industry Base”; Hebei Light Source Solar Energy Company is a provincial high-tech enterprises, with 13 national patents, reaching advanced levels at home and abroad; Hebei Sanhuan Solar Energy Co. Ltd. is listed as the scientific research base for solar energy utilization in Hebei Province, and was the first batch to pass the national CGC product quality certification exclusively in Hebei Province in 2006. These resources provide a favorable technical guarantee for the implementation of building solar integration construction and the creation of “solar building city”.
Xingtai City warm home residential district project total construction area of 283256 m2, single building 35, the district project all use solar shower water supply system, single solar collector 3408 units. In order to reduce the installation of solar energy systems in the construction process is very easy to damage the roof waterproofing, fixed stiffness and other problems, according to the design requirements for the implementation of building solar integration construction, in order to achieve the organic combination of building construction and solar energy system construction, and improve the safety of solar energy systems, the overall appearance of the building quality and aesthetics.
1. Building solar integration design
Xingtai City warm home residential area Xingtai City Architectural Design and Research Institute design. The design department first conducted a field survey of the surrounding environment of the proposed residential area, including the latitude of the location of the building, annual sunshine hours, annual solar radiation intensity, annual ambient temperature, etc.; then the building function (maximum daily heat volume, water supply mode, water temperature, water point location, etc.) and water heater installation conditions (site area, shape, building structure bearing capacity, shading, etc.) were fully The preliminary design scheme of building-like energy integration is proposed.
1.1 Civil building solar water heating system design points and main design steps
According to the “Technical Specification for the Application of Solar Hot Water Systems in Civil Buildings” (hereinafter referred to as GB50364-2005) building water supply and drainage professionals, in cooperation with the technical staff of solar energy enterprises, based on the requirements of the specification GB50364-2005, the design of solar hot water systems, while and should meet the requirements of other relevant national standards in force.
1.2 Determination of the type of solar water heating system.
The designers selected the system type according to the comprehensive factors such as the plan layout, façade effect and structural form of the whole district building, based on the specification GB50364-2005 Table 4.2.6, and chose its type, color and installation location to achieve coordination with the overall building and surrounding environment.
The district unified procurement of a solar energy company in Xingtai City, the vacuum tube solar collectors, pipe for the new material of aluminum-plastic composite tube (roof part of the pipe are used polyethylene foam insulation material insulation), the connection method for the hot fusion connection, indoor pipeline open installation.
2. Building solar integration construction
2.1 Construction organization
Participating parties (mainly supervision, construction enterprises) to establish a sound quality and technical management system. Clear construction technology quality control measures to ensure that the design quality requirements are met; construction of building solar energy by a team with professional construction qualifications for solar energy installation and the development of special construction programs to organize construction. Require serious implementation of the technical briefing system, to understand the technical control points of the installation system and the quality control of important processes such as pipe connection, anti-corrosion and anti-freeze, and to do a good job of pre-control of quality common problems that are likely to occur, to avoid poor fixation, damage to the waterproof layer, leakage and other quality problems.
Improve the technical quality and awareness of responsibility of the quality management personnel on site through technical training and design handover. For the design content is not detailed or does not pass the policy, technical construction drawing review, can not organize construction. Before construction should be solar water heater specifications size, pipe wells, fixed pre-buried parts, system layout, node practices, lightning protection settings and other content to make a detailed understanding of the construction quality pre-control strictly in accordance with the practice set selected in the drawings to ensure that the solar energy system and building structure combined with reasonable, easy to install and maintain and safe to use.
Check the quality certification documents of solar system equipment materials and accessories before construction, and conduct batch acceptance inspection of collector manufacturers, specifications, etc., and make detailed records to ensure the quality of raw materials and finished products.
2.2 Construction techniques and methods
The construction process of the vertical wall outside the open pipeline: solar energy system water supply pipe, overflow pipe behind the civil construction quality inspection and acceptance → installation → water pressure test → acceptance; roof pipeline, collector construction process: pre-buried fixed parts inspection → collector installation fixed → connection pipeline → water inspection → anti-corrosion insulation and lightning protection construction → system acceptance
2.3 Quality inspection
Connected with solar collectors and through the waterproof layer of the pipeline, around the additional layer of waterproofing, flooding height and detailing according to the specification “construction of water supply and drainage and heating engineering construction quality acceptance specification” (GB50242-2002) requirements.
Collector orientation set to be reasonable, generally facing south or 5 ° south of west; installation inclination and engineering location of the geographical latitude is basically the same, collector multi-row matrix arrangement, before and after the two rows between the appropriate distance to leave, generally for the former row of vertical height of about 2 times. The fixing of the collectors should be connected reliably with the pre-buried parts during the construction of the structure, and if there is a post-buried part, a pull-out test is required to ensure the wind resistance of the solar system [2].
Solar water heater set up lightning protection device according to the requirements of the drawings, and make a reliable connection with the building lightning network belt, shall not directly use the water heater as a flash catcher.
3. Solar energy system inspection and acceptance
3.1 Construction data
After the inspection of each building solar energy project information in the district, the construction of finished products, semi-finished products and other materials with complete and valid quality certification documents, water, water quality inspection reports and other acceptance information in line with relevant regulations and requirements.
3.2 Installation appearance quality
The solar water heater installation part of each residential project in the district was checked in full. No unqualified construction quality or the existence of safety hazard items, collector location, spacing and other dimensions in line with the design requirements, wind, corrosion, frost, lightning and fixed form can meet the requirements of use. Collector fixed bracket root and the surrounding roof waterproofing combined with reasonable, detailed practices meet the requirements.
4. Conclusion
4.1 Under the premise of reliable quality and technical measures, the construction quality of building solar integration can be guaranteed.
4.2 Building solar integration is the use of solar energy into the overall design of the project to integrate architecture, technology and aesthetics, solar facilities become part of the building, organic combination of each other, replacing the traditional solar structure caused by the impact on the appearance of the building image.
4.3 Solar energy and building integration is the organic combination of solar energy utilization facilities and buildings, avoiding secondary installation and reducing costs. It can also save coal and electricity resources and reduce air pollution from sulfur dioxide, dust and other emissions. Solar energy and building integration is the future direction of solar energy technology development.