Distributed photovoltaic roofing house safety appraisal third party - Huaqiang Electronic Network

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Third-party organizations for the safety appraisal of distributed photovoltaic roofing houses:
Distributed photovoltaic roofing house safety appraisal of third-party institutions, our company is a third-party independent legal entity established by law, with first-class routine inspection of construction and construction, construction foundation engineering inspection, steel structure engineering inspection, witness sampling inspection, building seismic detection, Special qualification certificate for on-site inspection of main structure engineering. Our company has departments such as Building Inspection, Business, Technical Quality, and Finance. Our company is a building engineering testing and appraisal unit established by a large domestic testing company. It has the qualifications of the State Bureau of Quality and Technical Supervision. It is the first-level testing and appraisal organization for construction engineering inspection in Guangdong Province. It has special qualification for steel structure testing and special inspection of main structure. Qualifications and testimonials such as sampling and testing qualifications, such as "Engineering Testing Qualification Certificate" and "Metrics Qualification Certificate", can issue a fair, legally effective and authoritative test and appraisal report. The company's main projects include: building materials witness testing, building quality testing, building safety testing, building seismic identification, building reliability appraisal, steel structure engineering materials and reliability appraisal, building curtain wall testing, dilapidated house safety assessment, anti-corrosion and Anti-rust detection, construction damage dispute identification, construction safety assessment and other authoritative testing special qualification certificates, welcome customers to inquire and cooperate, I will sincerely provide you with satisfactory service. Since the establishment of our company, we have always focused on the center of economic construction, seized opportunities, dared to develop, and actively introduced talents. Vigorously expand the scope of business, further establish and improve the operational mechanism to adapt to the market economy, fully mobilize the enthusiasm and creativity of the majority of scientific and technological personnel, and rapid development of material and spiritual civilization. Distributed photovoltaic roofing house safety appraisal of third-party institutions, looking for Shenzhen Zhongzheng Engineering Technology Co., Ltd., to undertake the national business scope, provide free technical consulting services, contact telephone, 15999691719 Manager Li

1. Third-party organizations for the safety appraisal of distributed photovoltaic roofing houses -

Characteristics of distributed photovoltaics:

The construction characteristics of distributed photovoltaic power plants. Everyone knows that all distributed photovoltaic power plants have been analyzed a lot, its characteristics, near power generation, near grid connection, the principle of near use, the country's definition of distributed, there is a definition of installed capacity, now under 20 MW . Relatively concentrated, the entire investment scale, because the grid is more convenient, you can choose the facility nearby. I have summarized it a bit. From the perspective of the construction characteristics of distributed power plants, according to this construction feature, why do we mainly push the EPC model, design, procurement and construction? At present, we have encountered many problems in the construction of distributed power plants. In terms of funds, there are inevitably some problems in terms of quality. I will talk about the characteristics. I think EPC has characteristics in terms of risk, investment and cost. Why is the difficulty of distributed development relatively large, because the number of power supply is more dispersed, although the industry is relatively developed in Guangdong, the roof is not a lot of roofs. If it is developed in a piece, many designs are required. Consider how to customize the system according to the number of entire roofs. From the design characteristics, the power plants under development are under production. How should they not be produced, and the design and construction plan is more reasonable. To install a battery pack on an existing roof, it is necessary to check whether the roof can increase the load. The access conditions vary, and the grid situation needs to be considered to arrive at the most reliable access plan. The coastal areas of Guangdong need to consider the impact of the typhoon. The construction characteristics, design and connection points of distributed photovoltaic power plants need to be based on the original distribution system to select the grid connection point and grid voltage level to build or renovate the power distribution room. According to the load point, the revenue is measured. In the case of the US 6 MW, the roof of the project is scattered, the access point is relatively far, and the roof has more equipment and lighting belts. Therefore, in the design process, the actual situation of the roof is first carried out. Simulation analysis, the most reasonable component layout is obtained, and then the position of the inverter and the box change is determined, the length of the cable is reduced as much as possible, and the transmission loss is reduced. The switch station adopts an outdoor container type according to the actual situation on the site, and does not occupy the production plant.

Second, distributed photovoltaic roofing house safety appraisal third-party institutions - distributed photovoltaic roofing house safety identification examples:
This time, the STK module of the structural calculation program PKPM (V3.1) of the China Academy of Building Research was used to model the typical rigid frame (1-7/E axis) according to the measured structural arrangement and the cross-sectional dimensions of the components. Carry out structural bearing capacity verification. The calculation model is shown in Figure 4.
(1) The original structural load check calculation results show that under the original structural load of the plant, the bending moment of the steel column and the ratio of the flexural bearing capacity after buckling and the in-plane stability stress ratio are all less than 1, satisfying the calculation requirements of bearing capacity, GZ2 The out-of-plane stability stress ratio of GZ6 is greater than 1, which does not meet the calculation requirements of bearing capacity; the bending moment of steel beam and the ratio of strength to bending capacity after buckling, the ratio of in-plane stability stress and the out-of-plane stability stress ratio are all less than 1, satisfying the bearing Force calculation requirements. The out-of-plane stable slenderness ratio of GZ2 does not meet the requirements of the specification, and the length-to-fine ratio of the remaining components meets the requirements of the specification. The results of the calculation are shown in Figure 5.
(2) Increasing the load of photovoltaic panels on the roof. Under the action of adding photovoltaic panels to the roof, the bending moments of the steel columns GZ3 and GZ4 are considered to be the ratio of the flexural bearing capacity after buckling, the in-plane stable stress ratio, and the out-of-plane stable stress ratio. 1, meet the bearing capacity calculation requirements; GZ1, GZ2, GZ7 in-plane stable stress ratio is greater than 1; GZ2, GZ7 in-plane slenderness ratio does not meet the calculation requirements; GZ2, GZ5, GZ6 out-of-plane stable stress ratio is greater than 1, does not meet the bearing Force calculation requirements; GZ2 out-of-plane length ratio does not meet the calculation requirements. The in-plane stability stress ratio, the out-of-plane stability stress ratio, the applied bending moment and the ratio of the flexural capacity of the steel beam after considering the buckling are all greater than 1, which does not meet the calculation requirements of the bearing capacity. The results of the column check are shown in Table 10.2, and the results of the check can be seen in Figure 6.
Under the original load, the stress ratio and stability of the main frame of the steel structure meet the requirements of the basic load; the fine ratio in the long plane of the component satisfies the calculation requirements; some steel columns have insufficient out-of-plane stability stress, and the out-of-plane aspect ratio does not meet the requirements of the specification. problem. After the roof load is changed, the GZ1 in-plane stable stress ratio does not meet the load usage requirements. The GZ2 in-plane stable stress ratio and the corresponding slenderness ratio, out-of-plane stabilizing stress ratio and the corresponding slenderness ratio do not meet the load use requirements, GZ5, GZ6 The out-of-plane stable stress ratio does not meet the load requirements. The GZ7 in-plane stable stress ratio and the corresponding slenderness ratio do not meet the requirements. The ratio of the bending moment of the steel beam to the flexural bearing capacity after buckling exceeds the limit. The calculation of the purlins meets the original load requirements before and after the roof load change. The wind column calculation does not meet the original load requirements.

Third, the third-party organization for the safety appraisal of distributed photovoltaic roofing houses - the content and basis of testing and identification:

(1) Survey of plant history and usage; (2) Survey of on-site structural drawings; (3) Inspection of factory appearance quality defects and structural damage; (4) Steel structural member material strength testing; (5) Deformation measurement (house settlement, column Verticality, beam deflection); (6) Checking the bearing capacity of the main structure; (7) Comprehensive appraisal and analysis.
Main technical basis (1) "Black metal hardness and strength conversion value" (GB/T1172-1999); (2) "Building deformation measurement procedures" (JGJ8-2016); (3) "Building structure testing technical standards" (GB /T50344-2004); (4) "Code for Acceptance of Construction Quality of Steel Structure Engineering" (GB50205-2001); (5) "Code for Loads of Building Structures" (GB50009-2012); (6) Specification for Design of Steel Structures (GB50017) -2003); (7) "Technical Regulations for Detection and Identification of Steel Structures" (DG/TJ08-2011-2007); (8) "Test Method for Hardness of Metallic Materials" (GB/T17394.1-2014)

Fourth, the third-party organization for the safety appraisal of distributed photovoltaic roofing houses - the status quo of technical level development

a) Although China's photovoltaic power generation technology is becoming more and more mature, large-area applications are gradually maturing, but many are limited to the ground. The big drawback is that the floor space is too large, and most of the construction sites are desert areas in western Inner Mongolia. After power generation, long-distance erection towers are needed. Send electricity to the grid. b) At present, China's industrial rooftop photovoltaic power station is in the exploration stage. At present, there is no large-scale application. Due to the complicated structure of the building and the complicated load situation, the industrial roof photovoltaic power station is currently in the exploration stage and there is no actual installation project. At present, the domestic rooftop photovoltaic power generation system stays on the concrete roof. Due to the strong bearing capacity of the concrete roof, a large number of photovoltaic panel installation techniques are difficult. Almost all domestic large-scale industrial plants use pressed steel roof slabs, bearing gravity difference, and the current technology application is in a blank stage. c) The maintenance of the upper-level power supply of the existing industrial plant cannot be completed at the same time. Even if the additional security is used for maintenance and repair, the investment cost of the security power supply is high and the maintenance cost is high. After the production is 3~5, the maintenance cost is high and the equipment is expensive. The reason is that it leads to waste and reduces the safety of production. Roof photovoltaic power plants provide a supplement to maintenance and security power during the day. For example, in the Beijing West Railway Station, there is no platform and pillar rain canopy reconstruction project. In the welding construction, a series of prevention and control measures are taken for the hidden dangers of steel structure welding construction which are prone to safety accidents. First of all, before construction, we should carefully analyze and formulate effective prevention and control measures. Secondly, during construction, we must strictly control and carefully manage, so that managers and construction personnel have a strong sense of “three no harm” and eliminate steel. Safety hazards in structural welding construction ensure safe operation, avoid all kinds of accidents and personal injuries, and ensure the smooth progress of the project.

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