Outline of the JSME Rules on Pipe Wall Thinning Management for Thermal Power Generation Facilities

Author(s):  
Isoharu Nishiguchi ◽  
Seiichi Hamada

In response to the pipe wall thinning damage experienced in power plants in 2004, the Japan Society of Mechanical Engineers (JSME) has started activities to develop technical standards on the pipe wall thinning management. The first edition of the JSME rules on pipe wall thinning management for thermal power generation facilities (JSME S TB1-2006 [1]) was issued in March 2006, and its latest edition will be issued in 2007, which describes the technical requirements to meet the JSME performance-based rules for pipe wall thinning management (JSME S CA-1 2005 [2]). Based on 24,774 inspection data obtained at the thermal power plants in Japan, the latest JSME rules will show the specific attention to the need for inspection of piping systems that are susceptible to the wall thinning damage. The JSME rules describe the selection of thickness measurement locations such as downstream of piping configurations that produce turbulence, downstream of orifices, downstream of control valves, and they describe the periodic inspections including the first inspection to be scheduled taking the wall thinning rate data at the equivalent locations into consideration. The JSME rules stipulate some available inspection methods such as ultrasonic scanning, radiographic profile, eddy current and potential drop technique. This paper presents outline of the JSME rules including basic philosophy, technical requirements on the inspection and testing practices and the relation with the regulations in Japan.

Author(s):  
Shin Yoshino ◽  
Seiichi Hamada ◽  
Manabu Hayakawa

The electrical potential drop technique is one of the promising methods for monitoring the pipe wall thinning. In order to verify this method, preliminary thickness measurements were conducted for uniform and local thinning created on plate specimens. The result showed the electrical potential drop technique had a good performance equal to the ultrasonic testing method. The success in the preliminary tests allowed this technique to be applied to some pipes in thermal power plants in order to monitor the wall thinning and this on-line monitoring has continued for two to three years. It was confirmed that this technique was valid in terms of a long-term durability. Following these results, technical requirements on the potential drop technique were proposed to the JSME (the Japan Society of Mechanical Engineers) Rules on Pipe Wall Thinning Management for Thermal Power Generation Facilities (JSME S TB1-2006) and stipulated in those rules. In this paper, these rules are simply introduced and the on-line monitoring of the pipe wall thinning by means of the electrical potential drop technique is discussed through the results in the plate-specimen-tests and the real-pipe-tests in operating thermal power plants.


Author(s):  
Shin Yoshino ◽  
Seiichi Hamada ◽  
Yoshi Kaieda

The electrical potential drop technique is one of the promising methods for monitoring the pipe wall thinning. In the previous paper [1], it was reported that this technique had a good performance equal to the ultrasonic testing in the preliminary test and that it had a long-term durability under a severe condition on the real pipes in operating thermal power plants. This time one of these pipes was replaced because its thickness approached the threshold. The removed pipe was cut in many pieces and its thickness was measured with calipers at several locations corresponding to where the electrical potential drop technique was applied. This result was compared with the thickness resulted from this technique and the conventional ultrasonic testing that were conducted just before the pipe removal. This comparison led to the conclusion that the accuracy in the electrical potential drop technique was almost equivalent to that in the ultrasonic testing even in the real pipe under a severe condition. In this paper, the accuracy in the electrical potential drop technique is mainly discussed.


Author(s):  
Isoharu Nishiguchi ◽  
Fumitoshi Sakata ◽  
Seiichi Hamada

A method to investigate pipe wall thinning using guided waves has been developed for pipes in thermal power generation facilities. In this paper, the reflection coefficient and the transmission coefficient are derived for the torsional waves which propagate along a pipe and a simplified method to predict the waveform is proposed. The predictions of the waveforms by the FEM and a simplified method based on the reflection of torsional waves are also examined by comparing with experimental data.


Author(s):  
M.V. Cherniavskyi

The structure of electricity cost formation for consumers, including depending on the cost of TPP generation, «green» energy and other sources, is investigated, and the main conditions of the efficient regulatory function fulfillment in the power system by thermal power generation in the conditions of Ukraine's course on carbon-free energy are formulated. It is shown that excessive electricity losses in networks and, especially, accelerated increase of the share of «green» generation, much more expensive than nuclear, hydro and thermal, mainly contribute to the growth of electricity costs for non-household consumers and the need to raise tariffs for the population. This accelerated increase directly contradicts the Paris Climate Agreement, according to which plans to reduce Ukraine’s greenhouse gas emissions must be developed taking into account available energy resources and without harming its own economy. The dependences of the specific fuel consumption on the average load and the frequency of start-stops of units are found and it is shown that the increased specific fuel consumption on coal TPPs is an inevitable payment for their use as regulating capacities of UES of Ukraine. In this case, the higher the proportion of «green» generation and a smaller proportion of generating thermal power plants, especially increasing specific fuel consumption. It is proved that in the conditions of growth of the share of «green» generation in Ukraine the share of production of pulverized coal thermal power plants should be kept at the level of not less than 30 % of the total electricity generation. It is substantiated that a necessary condition for coal generation to perform a proper regulatory role in the power system is to introduce both environmental and technical measures, namely — reducing the suction of cold air to the furnace and other boiler elements, restoring condensers and cooling systems, etc. An important factor in reducing the average level of specific fuel consumption is also the reduction of coal burn-out at thermal power plants, where it still remains significant, due to the transfer of power units to the combustion of bituminous coal concentrate. Bibl. 12, Fig. 5, Tab. 5.


Author(s):  
Kimitoshi Yoneda ◽  
Ryo Morita ◽  
Kazutoshi Fujiwara ◽  
Fumio Inada

Flow accelerated corrosion (FAC) and liquid droplet impingement erosion (LDI) are the main pipe wall thinning phenomena in piping system of power plants in Japan. Authors have promoted the development of prediction method to evaluate local thinning trend by FAC/LDI. To apply the method to pipe wall thinning management in power plants, it is required to be transformed into practical tools for easy usage. In Japan, discussion is being made to considerate the introduction of prediction tools into wall thinning management based on wall thickness measurement at present. Authors have simplified their FAC/LDI models to predict wall thinning trend one-dimensionally along piping layout, and applied to actual thinning data of power plants. With PWR’s FAC data and BWR’s LDI data, maximum thinning rate for each pipe elements were roughly predictable with considerable accuracy. Especially for high thinning rate data, which is important in plant management, the model was able to evaluate within the factor of 2. By installing this model, prediction software “FALSET” was developed, equipped with practical functions for the management. With the further verification and improvement of each function, there are prospects for this software to be utilized as a management tool in power plants.


Author(s):  
Akinori Tamura ◽  
Chenghuan Zhong ◽  
Anthony J. Croxford ◽  
Paul D. Wilcox

A pipe-wall thinning measurement is a key inspection to ensure the integrity of the piping system in nuclear power plants. To monitor the integrity of the piping system, a number of ultrasonic thickness measurements are manually performed during the outage of the nuclear power plant. Since most of the pipes are covered with an insulator, removing the insulator is necessary for the ultrasonic thickness measurement. Noncontact ultrasonic sensors enable ultrasonic thickness inspection without removing the insulator. This leads to reduction of the inspection time and reduced radiation exposure of the inspector. The inductively-coupled transducer system (ICTS) is a noncontact ultrasonic sensor system which uses electromagnetic induction between coils to drive an installed transducer. In this study, we investigated the applicability of an innovative ICTS developed at the University of Bristol to nuclear power plant inspection, particularly pipe-wall thinning inspection. The following experiments were performed using ICTS: thickness measurement performance, the effect of the coil separation, the effect of the insulator, the effect of different inspection materials, the radiation tolerance, and the measurement accuracy of wastage defects. These initial experimental results showed that the ICTS has the possibility to enable wall-thinning inspection in nuclear power plants without removing the insulator. Future work will address the issue of measuring wall-thinning in more complex pipework geometries and at elevated temperatures.


2021 ◽  
Vol 2083 (3) ◽  
pp. 032068
Author(s):  
Lijun Fan ◽  
Jiedong Cui

Abstract This paper proposes a renewable energy system based on photovoltaic power generation, wind power generation and solar thermal power generation, combining thermal power plants with low-temperature multi-effect distillation. Through the electric heater and the thermal storage system photovoltaic and wind power will spare capacity in the form of heat energy, at the same time by thermal power generation system to maintain the stability of the power supply, run under constant output scheduling policy, to the levelling of the smallest energy cost and the design of power rate of maximum satisfaction as the goal, using multi-objective particle swarm optimization (PSO) algorithm to find the best combination of capacity, this system is established. At the same time, combined with low-temperature multi-effect distillation, compared with reverse osmosis seawater desalination cost is lower, reduce energy consumption, has a good application prospect.


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