94 thermal efficiency cast iron boilers
Fast 94 thermal efficiency cast iron boilers is in Anyang City, scientific and technological innovation high bar business, we already heard. After this cooperation really deserved reputation, since the boiler to provide us with a self-running, never malfunction or accident. It comes with a complete remote monitoring service, eliminating our worries. --customer feedback
S: double drum. There are two drum 94 thermal efficiency cast iron boilers, goes under the distribution structure.
Z: vertical type. Using the "D" type arrangement, arranged longitudinally down drum, as the flue gas flow partition Wall full mode, the left side of the boiler convective tube bank is arranged.
Inspection of Manufacturing quality of pressure-bearing equipment products
2.1 purpose and significance: The inspection of the manufacturing quality of boiler and pressure vessel products is carried out under the premise of qualified inspection of the finished products of the product quality in the manufacturing plant, and it is a kind of confirmatory sampling inspection of the product quality. This kind of inspection is legal inspection and is carried out according to the plan of boiler product safety supervision and inspection, which plays a key role in the control and control of boiler product quality. At the same time, it is also to implement the national and industrial requirements for the production and manufacturing of pressure components in the whole process of technical monitoring, for the user to re-control the quality of the product.
2.2 Product quality supervision and inspection: This type of inspection is usually carried out before installation (boiler and pressure vessel manufacturing plant). In order to implement the policy of "safety first, prevention first", the equipment can be shipped to the site, accompanied by out-of-the-box inspection at the same time, or it can be carried out in the manufacturing plant ahead of time before the product leaves the factory. We adopt the latter and supervise the product according to the boiler product safety and quality inspection plan. In this way, the problems in the manufacturing process of the products can be better found and solved in the factory, and the quality defects of the products can be eliminated before leaving the factory. This is also the "zero defect of equipment to the site", to avoid the product in the construction site again. Now the problem is difficult to deal with and repair problems, even equipment returned to the factory to deal with. In this way, no matter from the technical difficulty, repair quality, site time limit, or from the economic cost is beneficial.
2.3 Inspection items: The installation supervision and inspection is carried out on the basis of the inspection qualification of the manufacturing plant, and in the course of such inspection, it was carried out on the spot in accordance with the Supervision and Management rules of the Boiler installation and renovation Units and the Boiler installation Supervision and Inspection rules. Consult the relevant technical documents and drawings provided by the manufacturing plant, and verify the qualification of the installation and retrofitting units at the same time. By consulting the materials, you can know whether the manufacturer has completed the inspection required by the above two "rules" in accordance with the relevant rules and regulations, and check whether the supervisory inspection department has issued a qualified certificate of supervision and inspection. Ensure that the equipment supplied to the user is qualified in the product produced by the manufacturer.
2.4 key monitoring: The quality of construction supervision on the spot is to pay attention to the parts with worse working conditions, higher risk and higher safety requirements on the parts of high temperature, high pressure and high alloy. For example, most utility boilers are coal fired furnaces, with sub-critical and ultra-critical furnaces. The inspection items of their components and the ratio of non-destructive testing are different. Class A boilers are tested for non-destructive testing of installed welded joints. Check the hardness of welded joints of high alloy steel at least 1% per pipe. At least 10% of samples per material and at least the number of joints per component when all welded joints are to be radiologically tested Twenty percent of them were tested on a spot basis. The emphasis is on the film before and after the repair, the quality of the film, whether the defect evaluation meets the relevant standard requirements, for the pressure vessel welding quality inspection, the high-pressure heater and the air tank are not the same treatment. Air tanks in accordance with the normal proportion of spot checks, and high-pressure heaters to increase the strength of sampling.
2.5 problems identified in monitoring： In the past 30 years, many kinds of defects have been found, such as the defects of welding joints exceeding the standard, the base metal defects, the misused materials and the deviation of heat treatment effect, and so on. Here are four typical examples:
2.5.1 cracks in the tube seat of the drum descent pipe. During the acceptance inspection of a steam drum in a power plant, the defects in fillet weld of one of the centrally descending pipe seats were first discovered, and then the inspection was expanded. It was found that there was a large area of linear defects at the end of the pipe seat in the drum. It is also found that the defects in the forgings are cracks caused by inclusions, as shown in fig. 1 and fig. 2, as shown in Fig. 1 and FIG. 2, further extended to the inspection of the other three pipe bases, and the same type of defects are also found to exist in the forgings to varying degrees. The reason may be that the supplier is not in control. Resulting in a total of 8 such parts, all of which were abolished, removed and replaced.
2.5.2 cracks in the outside of the economizer tube in the drum. During an internal and external inspection, a number of bulging cracks were found on the outlet pipe wall of the economizer inside the drum, all of which distributed on the surface of the pipe wall. The on-the-spot visual analysis shows that the temperature of the feed water entered into the drum is on the low side, but the injection pressure is high. However, the quality control of the economizer tube in its manufacturing plant is not strict, and no inclusions have been found in the forging parts. The bulging crack defect caused by the installation and operation of the construction site for several years requires replacement.
2.5.3 P91 header weld crack. High alloy material P91 is widely used in boilers of supercritical units. It is mainly used in the header and pipe in the high temperature section, the welding process of this material is very high. Any link handled improperly, there may be defects. There are many defects in the butt weld root of the joint weld of the P91 material of a factory when it is not carried out according to the welding procedure in the manufacturing field, which results in a large number of weld rework.
2.5.4 defect in fillet weld of header connection pipe. Not only cracks will occur in the weld seam of the high alloy header, but also defects will occur in the low alloy header at the time of the process, such as the surface crack of the fillet weld of the header seat, the incomplete weld penetration, the infusion, the crack and so on.
After thousands of trials 94 thermal efficiency cast iron boilers, proper selection of the parameters, compared with the conventional gas boiler, to save more than 20% area of lower capital requirements of the boiler room, the user inputs the cost is also reduced.