JP2005127183A - Piping installation method of steam turbine plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly perform construction and tests by synchronizing electric/instrumentation tests, heat insulation construction, and painting work, etc. with each other. <P>SOLUTION: When a schedule for the piping installation of a steam turbine plant is prepared, the range of piping to be hydraulically tested is divided into multiple piping systems, and piping works, hydraulic tests, and heat insulation/painting works are performed in order for each divided piping system. Also, the priority of the construction of the divided piping systems is determined beforehand, and after the installation of steam turbine plant equipment is completed, carrying of piping and assembling of scaffolds are performed in order. Then, the piping works are performed starting at the first piping system in the priority order defined in the piping work schedule. After the first piping work is completed, the hydraulic test of the first piping system is performed, the piping work and hydraulic test of the second piping system are performed. Hereafter, in the same manner, the third piping work or subsequent are hydraulically tested and then the heat insulation/painting works are performed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a piping construction method for passing a fluid such as steam, gas, air, and liquid in a steam turbine plant, and in particular, a piping construction method for a steam turbine plant capable of smoothly performing various constructions and tests. About.

FIG. 3 is a process map of a conventional method related to a steam turbine pipe water pressure test.
In FIG. 3, when the installation of the steam turbine plant equipment is completed (ST3-1), the piping is then suspended (ST3-2). At the same time, the installation of the platform will be carried out for the places where the platform can be used as a scaffold during the piping suspension work.

  Next, assembling the scaffolds for connecting the pipes (ST3-3), and then performing piping work in the order of pipe matching, preheating, welding, and annealing (ST3-4). For this piping work, depending on the type of fluid flowing in the piping, temperature or pressure, etc., piping of the low pressure heater system (bleeding pipe), condensate system, high pressure water supply system, low pressure water supply system, bearing cooling system, boiler replenishment water system There is construction.

  After all such piping work is completed, the low pressure heater system (bleed pipe), condensate system, high pressure water supply system, low pressure are used to confirm the presence or absence of pressure drop, leakage and deformation as the final inspection of the welding inspection. A plant water pressure test (pipe pressure resistance test) is collectively performed on the water supply system, the bearing cooling system, and the boiler replenishment water system (ST3-5). The test pressure at this time is 1.5 times the maximum operating pressure, and these methods are defined by the Electricity Business Act.

  After this collective plant water pressure test is completed, an electrical / instrumentation test (ST3-6) is performed, followed by heat insulation work and painting work (ST3-7) in that order. The scaffold was dismantled (ST3-8).

By the way, in recent years, since regulations have been relaxed in power plant construction work, self-inspection has been carried out in place of conventional government witness inspection. As a result, the intermediate inspection of the turbine main machine installation was changed from the witness inspection to the self-inspection, and the turbine main machine installation process, which was a conventional critical process, was shortened and is no longer a critical process.
On the other hand, due to advances in automation, the number of electrical products and instrumentation such as thermocouples that are directly attached to piping has been increasing year by year, and the piping process has become a critical process instead of the turbine main machine installation process.

  However, in the pipe construction process so far, there is a part where the pipe work and electrical / instrumentation test, heat insulation work, painting work, etc. do not synchronize, resulting in a temporary increase in man-hours. A new problem has arisen, such as securing a large number of workers and high loads on workers.

  The present invention has been made in view of the above-described circumstances, and is a steam turbine plant that prevents wrinkles from affecting the electrical work, instrumentation test, heat insulation work, painting work, etc. performed downstream of the piping work, water pressure test. The purpose is to provide a pipe construction method.

  In order to solve the above-described problem, the invention of the piping construction method for a steam turbine plant according to claim 1 is the pipe water pressure test scheduled for the piping construction process creation related to piping for passing various fluids used in the steam turbine plant. It is determined that the piping is divided into a plurality of piping systems according to the target range, and the piping work, water pressure test and heat insulation / painting work are determined for each piping system, and construction between the piping systems. After the installation of the steam turbine plant equipment is completed, the piping is suspended and the scaffold is assembled in order, and then the piping work is performed from the first piping system according to the priority order determined between the piping systems. After the first piping work is completed, if the second piping system is constructed on the condition that the scaffolding assembly of the second piping system is completed In addition, after the hydraulic test of the first piping system is performed and the piping work of the second piping system is completed, the scaffolding assembly of the third piping system is completed, and the third piping system is completed. In addition, the water pressure test of the second piping system is performed, and after the piping work of the final piping system is completed in the same manner, the water pressure test of the final piping system is performed. After each water pressure test, heat insulation / painting work was performed, and finally the scaffold was dismantled.

  According to the present invention, the piping is determined to be divided into a plurality of piping systems or areas according to the planned turbine piping water pressure test target range, and the turbine piping work and the piping water pressure test are performed for each piping system or each area. As a result, it is possible to move to the next scheduled work after completion of the turbine piping water pressure test by piping system or by area, and to the downstream processes of electrical and instrumentation testing, heat insulation work, and painting work. Can reduce wrinkling. As a result, the problem of securing workers and testers or high load can be solved, and the process can be shortened.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a process map of a piping construction method for a steam turbine plant according to a first embodiment.
In the present embodiment, a piping work process is first created (ST1-1). In this example, the planned piping water pressure test target areas of the four systems (for example, (1); low pressure heater system (bleed pipe), (2); condensate system, (3); high pressure) Corresponding to the water supply system (4); low pressure water supply system, bearing cooling system and boiler replenishment water system), the piping is also divided into four systems. For convenience, (1) is called the first piping system, (2) is called the second piping system, (3) is called the third piping system, and (4) is called the fourth piping system.

The piping work process will be prepared for each system mainly considering the following matters.
(A) Which system should be used first among a plurality of systems? Also, by when will it be necessary to finish each system?
(B) Securing the electrical / instrumentation test period.
(C) Securing the heat insulation work period.
(D) Securing the painting work period. Such

  After creating the piping work process, the installation work of the steam turbine plant equipment is performed, and after the work is completed (ST1-2), the piping is suspended. At that time, with respect to the place where the mount can be used as a scaffold, the piping is suspended and the mount is installed at the same time (ST1-3).

  Next, assembling scaffolds for connecting pipes for each system (ST1-4), and then performing piping work for each system described above (ST1-5). The priority order of the piping work for each system is as follows. The piping work ST1-51 of the first piping system, the piping work ST1-52 of the second piping system, and the piping work of the third piping system are prepared when the piping work process is created. Since it is determined to perform in the order of ST1-53 and the piping work ST1-54 of the fourth piping system, it is performed in accordance with the order.

First, the piping work of the first piping system is performed in the order of pipe alignment, preheating, welding, and annealing (ST1-51). After the completion of the piping work for the first piping system, the piping work for the second piping system (ST1-52) is performed on the condition that the scaffold assembly of the second piping system is completed. In the first piping system, a piping pressure resistance test (ST1-61) is performed.
This piping pressure test is a pressure test for confirming whether there is no pressure drop, leakage, or deformation as a final inspection of the welding inspection described in the background art section.

  Then, after the piping work for the second piping system (ST1-52) is completed, the piping work for the third piping system (ST1-53) on the condition that the scaffold assembly of the third piping system is completed. I do. In the second piping system, a piping pressure resistance test (ST1-62) is performed.

In the same manner, after the piping work for the third piping system (ST1-53) is completed, the piping work for the fourth piping system is performed on the condition that the scaffold assembly of the fourth piping system is completed. (ST1-54), a piping pressure test (ST1-63) of the third piping system is performed.
And after the piping work of the 4th piping system is completed, the piping pressure resistance test (ST1-64) of the 4th piping system is performed.

  In this manner, the piping pressure test is continuously performed after the piping work is completed for each piping system. Since the water pressure test is sequentially performed from the system where the piping work has been completed, it is not performed collectively as in the conventional case.

  In each system, after the piping pressure test is completed, the electrical / instrumentation test (ST1-71, ST1-72, ST1-73, ST1-74), the heat insulation work and the paint work (ST1-81, ST1), respectively. -82, ST1-83, ST1-84), and after completion of the painting work, the scaffold dismantling (ST1-91, ST1-92, ST1-93, ST1-94) is performed.

  As described above, according to the present embodiment, piping for passing various fluids used in the steam turbine plant is divided into a plurality of piping systems based on the turbine piping water pressure test range, and the divided piping systems are divided. Since piping work, water pressure test, and heat insulation / painting work were carried out sequentially for each process, even if work was delayed in the upstream process of any system, the delay was downstream in all systems as before. You can reduce wrinkles.

  As a result, it is possible to solve the problem of securing workers and testers due to the temporary increase in man-hours as in the past, or to solve the problem of high load, and by dividing the water pressure test of all systems Since there is no need to wait for completion, the process can be shortened.

  FIG. 2 is a process map of a piping construction method for a steam turbine plant according to the second embodiment. In this embodiment, the turbine pipe water pressure test target range of piping for passing various fluids used in the steam turbine plant is divided into areas instead of being divided into a plurality of piping systems as in the first embodiment. It is a thing.

  Also in FIG. 2, similarly to FIG. 1, an area-specific piping work process is first created (ST2-1). In this embodiment, the area is divided into (1); deaerator and heater area, and (2); other areas, but the area can be flexibly divided according to the situation by changing the division location. Also good. In this embodiment, for convenience, (1) is referred to as the first area and (2) is referred to as the second area, and the first area is preferentially given priority over the second area to perform work such as construction and testing.

  After the construction process is created, the installation operation of the steam turbine plant equipment is performed in the same manner as in FIG. 1, and after the operation is completed (ST2-2), the piping is suspended. At that time, for the place where the mount can be used as a scaffold, the piping is suspended and the mount is installed at the same time (ST2-3).

  Next, scaffold assembly (ST2-4) for connecting pipes by area is performed, and then piping work is performed for each divided area. Since the priority order of this area-specific piping work is determined in the order of the first area piping work (ST2-51) and the second area piping work (ST2-52) when creating the above-described construction process, Follow that order.

First, in the first area piping work, work is performed in the order of pipe alignment, preheating, welding, and annealing (ST2-51). After the first area piping work is completed, the second area piping work is performed on the condition that the scaffolding assembly of the second area is completed (ST2-52). In the first area, a pipe pressure resistance test (ST2-61) is performed. This piping pressure test is the same as the test described in the first embodiment. In the second area, after the second area piping work (ST2-52) is completed, a piping pressure test (ST2-62) is performed.
As described above, the water pressure test is sequentially performed from the system where the piping work has been completed, and is not performed collectively as in the past.

  Then, after the pipe pressure resistance test (ST2-61, ST2-62) is completed in each area, the electrical / instrumentation test (ST2-71, ST2-72), heat insulation work, and painting work (ST2) in each pipe area. -81, ST2-82), and after the painting work is completed, the scaffold is dismantled (ST2-91, ST1-92).

  As described above, according to the present embodiment, the pipe for passing various fluids used in the steam turbine plant is divided into a plurality of areas based on the turbine pipe water pressure test range, and for each divided area. Since piping work, water pressure test, and heat insulation / painting work are carried out sequentially, the wrinkles to the downstream process can be reduced even if there is a delay in the upstream process. As a result, similar to the first embodiment, the problem of securing workers and testers or high load can be solved, so that the process can be shortened.

The process map of the piping construction method of the steam turbine plant by Example 1 of this invention. The process map of the piping construction method of the steam turbine plant by Example 2 of this invention. Process map of piping construction method for steam turbine plant in the prior art.

Claims (4)

When creating piping work processes related to piping for passing various fluids used in steam turbine plants, it is determined that the piping is divided into multiple piping systems according to the planned piping water pressure test target range. Each pipe work, water pressure test and heat insulation / painting work are set up in order, and further priority is given to the work between the pipe systems,
After the installation of the steam turbine plant equipment is completed, the piping is suspended and the scaffold is assembled in order, and then the piping work is performed from the first piping system according to the priority order determined between the piping systems. After completion, the second piping system is subjected to piping work on the condition that the scaffolding assembly of the second piping system is completed, and the water pressure test of the first piping system is performed to obtain the second piping system. After the completion of the piping work, the piping work of the third piping system is performed on the condition that the scaffolding assembly of the third piping system is completed, and the water pressure test of the second piping system is performed. Similarly, after the piping work of the final piping system is completed, the water pressure test of the final piping system is performed,
A piping method for a steam turbine plant, wherein each piping system is subjected to the water pressure test, followed by heat insulation and painting work, and finally dismantling the scaffolding.   The steam turbine pipe construction method for a power plant according to claim 1, wherein the pipe water pressure test target range is divided into a plurality of pipe systems according to the type, pressure or temperature of the fluid flowing in the pipe.   The steam turbine pipe construction method for a power plant according to claim 1, wherein the pipe water pressure test target range is divided into a plurality of piping areas instead of being divided into a plurality of piping systems. 4. The steam turbine piping method for a power plant according to claim 3, wherein the piping area is divided into a deaerator and a heater area and other areas.

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