Investigation of Steam Desuperheater Waterhammer

2004 ◽  
Author(s):  
Gregory Zysk
Keyword(s):  
Analytical Methods ◽  
Distribution Network ◽  
Water Injection ◽  
Root Cause ◽  
Water Interaction ◽  
Design Changes ◽  
High Level ◽  
Steam System ◽  
Excessive Water

Steam supplied to an underground piping distribution network from a fossil fired boiler is desuperheated using water injection valves. Waterhammers occurred in the system, failing a valve on two separate occasions. Operations personnel also experience excessive high-level alarms at drain stations local to the valves. An investigation was conducted to determine the root cause of the valve failures and the cause of the excessive water in the steam system. Mitigating design changes were also proposed to solve these problems. Available analytical methods were shown to be effective in predicting waterhammer occurrence and magnitude. These methods can be used to evaluate the potential for waterhammer in similar systems with potential steam/water interaction.

scholarly journals Determining Root Cause of Construction Waste Generation: A Global Context

2018 ◽  
Vol 4 (11) ◽  
pp. 2539 ◽  
Author(s):  
Suaathi Kaliannan ◽  
Sasitharan Nagapan ◽  
Abd Halid Abdullah ◽  
Samiullah Sohu ◽  
Ashfaque Ahmed Jhatial
Keyword(s):  
Cross Validation ◽  
Construction Sector ◽  
Waste Generation ◽  
Main Root ◽  
Huge Amount ◽  
Construction Waste ◽  
Global Context ◽  
Root Cause ◽  
Gdp Growth Rate ◽  
Design Changes

Construction sector is one of the main sectors in contributing Gross Domestic Product (GDP) growth rate in every developing country. The rapid growth of this sector directly produces a huge amount of construction waste. Hence, to find out the main root causes of the generation, this paper aimed to determine root causes of the construction waste generation in the construction sector. The research is carried out through triangulation technique (questionnaire survey and practitioner’s validation). This technique is adopted to facilitate cross validation by analysing 38 articles and then the final results have been validated by construction practitioners. A total of 80 root causes were identified from 38 articles and the 5 main root causes determined have scored more than 50% out of the total number of articles. Finally, the result was validated and found out that 87.5% of construction practitioners agree with the findings. The agreed root causes are ‘Constant design changes’, ‘Incorrect storage of materials’, ‘Poor handling of materials’, ‘Effect of weather’ and ‘Mistakes while ordering from suppliers’. Therefore, these initial findings will be able to aid the construction practitioner (contractors, consultants and developers) to be aware of the root causes that is mostly causing construction waste generation.

Przegląd czynników wpływających na skuteczność nawaniania gazu

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (8) ◽  
pp. 553-560
Author(s):  
Anna Huszał ◽  
Keyword(s):  
Distribution Network ◽  
Field Measurements ◽  
International Standards ◽  
Odor Intensity ◽  
Operational Experience ◽  
Minimum Concentration ◽  
Gas Network ◽  
Natural Gases ◽  
High Level ◽  
The Cost

Due to rapid advancement in technology, the odorization process in Poland seems to be increasingly stabilized in practice and conducted at a sufficiently high level. International standards are adopted in this regard. One of the most important requirements for the natural gases quality delivered to customers from a distribution network, guaranteeing their safe use is ensuring an appropriate odorization level, allowing to detect the uncontrolled gas leakages from the distribution network, installation and gas appliances. The odorant concentration in its dosing point should ensure the intensity of the gas odor at the “clearly perceptible” level at the network end point. The odorant concentration variability in the gas network is a dynamic value, constantly accompanying the odorizing process. In consequence constant metrological supervision over the process is needed (what might be done by measuring the odorant concentration and gas odor intensity). Also, verification of undergoing periodic changes in the value of the minimum concentration of odorant in the gas for the respective groups of natural gases and various gas pipelines based on operational experience and field measurements is required. Such verification allows to determine the optimal concentration of odorant for each group of natural gases and furthermore allows to optimize the cost of gas odorization process while ensuring its legally required quality described as odor intensity. This article presents the problem of the dependence of the network gas odorization effectiveness on various factors, especially network parameters or even the gas composition itself. Their identification allows to better plan the process and ensure its effective implementation, which ultimately ensures safety for gas users.

A comprehensive evaluation of water injection in the diesel engine

2021 ◽  
pp. 146808742110442
Author(s):  
Sebastian Welscher ◽  
Mohammad Hossein Moradi ◽  
Antonino Vacca ◽  
Peter Bloch ◽  
Michael Grill ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Internal Combustion Engines ◽  
Comprehensive Evaluation ◽  
Combustion Engine ◽  
Water Injection ◽  
Combustion Process ◽  
Internal Combustion ◽  
Exhaust Emission ◽  
Pressure Trace ◽  
High Level

Due to increasing climate awareness and the introduction of much stricter exhaust emission legislation the internal combustion engine technology faces major challenges. Although the development and state of technology of internal combustion engines generally reached a very high level over the last years those need to be improved even more. Combining water injection with a diesel engine, therefore, seems to be the next logical step in developing a highly efficient drive train for future mobility. To investigate these potentials, a comprehensive evaluation of water injection on the diesel engine was carried out. This study covers >560 individual operating points on the test bench. The tests were carried out on a single-cylinder derived from a Euro 6d four-cylinder passenger car with the port water injection. Furthermore, a detailed pressure trace analysis (PTA) was performed to evaluate various aspects regarding combustion, emission, etc. The results show no significant effects of water injection on the combustion process, but great potential for NOx reduction. It has been shown that with the use of water injection at water-to-fuel rates of 25%, 50%, and 100%, NOx reduction without deterioration of soot levels can be achieved in 62%, 40%, and 20% of the experiments, respectively. Furthermore, water injection in combination with EGR offers additional reduction in NOx emissions.

Flow-Induced Vibration Analysis of a Water Injection System at Elevated Flow Rates of an FPSO

2019 ◽  
Author(s):  
Néstor González Díez ◽  
Juan P. Pontaza ◽  
Oluwaseun M. Awe ◽  
Pieter van Beek ◽  
Can Tümer
Keyword(s):  
Mechanical Response ◽  
Optimization Technique ◽  
Water Injection ◽  
Element Model ◽  
Injection System ◽  
Response Analysis ◽  
Flow Induced Vibration ◽  
Flow Rates ◽  
Screening Analysis ◽  
High Level

Abstract The water injection system of an FPSO active in the Gulf of Guinea is to increase injection capacity to levels that are threatening from a flow-induced vibration perspective, such that hydrocarbon recovery can be accelerated. A three-tier method based on the internal guidelines of the system operator has been employed to assess the level of FIV threat expected from the increase in flow rate. A high-level screening analysis is followed by a more detailed approach, modified in this case by introducing knowledge obtained from field data gathered during a comprehensive measurement campaign aboard the FPSO. In particular, the data has been used to calibrate the finite element model of the mechanical layout of the pipework and associated supporting by making use of an optimization technique. The PSD of the flow excitation has been calibrated to match the measured response of the system, with descriptions of the turbulent excitation introduced in elbows by means of PSD functions available in the open literature. The PSDs, once calibrated, are further scaled to the future flow-rates so that they can be used as input to the mechanical response analysis. Though the high-level screening analysis delivers the conclusion that flow rates should be limited, the detailed analysis proves that the expected vibrations will be acceptable.

scholarly journals Route Optimization for the Distribution Network of a Confectionary Chain

2015 ◽  
Vol 27 (6) ◽  
pp. 497-503
Author(s):  
Anıl İnanlı ◽  
Başak Ünsal ◽  
Deniz Türsel Eliiyi
Keyword(s):  
Time Windows ◽  
Distribution Network ◽  
Real Data ◽  
Route Optimization ◽  
Routing Problem ◽  
Hard Time ◽  
Np Hard Problem ◽  
Commercial Solver ◽  
High Level ◽  
The Cost

This study considers the distribution network of a well-known perishable food manufacturer and its franchises in Turkey. As the countrywide number of stores is increasing fast, the company is facing problems due to its central distribution of products from a single factory. The objective is to decrease the cost of transportation while maintaining a high level of customer satisfaction. Hence, the focus is on the vehicle routing problem (VRP) of this large franchise chain within each city. The problem is defined as a rich VRP with heterogeneous fleet, site-dependent and compartmentalized vehicles, and soft/hard time windows. This NP-hard problem is modelled and tried with real data on a commercial solver. A basic heuristic procedure which can be used easily by the decision makers is also employed for obtaining quick and high-quality solutions for large instances.

Condensation Induced Waterhammer in District Steam Distribution Systems

2013 ◽  
Author(s):  
Sri K. Sinha ◽  
Robert S. Vecchio ◽  
Paul M. Bruck ◽  
Thomas C. Esselman ◽  
Gregory Zysk ◽  
...  
Keyword(s):  
New York ◽  
Distribution Systems ◽  
Construction Materials ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Excessive Pressure ◽  
Root Cause ◽  
Steam Pipe ◽  
Event Based ◽  
Steam System

Condensation induced waterhammer in district steam distribution systems can cause catastrophic rupture of piping and inflict severe damage to personnel, property, and environment. On July 18, 2007, a 20-in. diameter underground steam pipe in New York City ruptured at 5:56 p.m. at the intersection of 41st Street and Lexington Avenue in midtown Manhattan. At the time of rupture, the steam system was in service delivering steam to the customers at an operating pressure of approximately 160 psig and a steam temperature of approximately 370°F. The incident opened a large cavity measuring approximately 32 ft × 32 ft × 18 ft deep at the intersection of 41st Street and Lexington Avenue. The pipe rupture released steam, condensate, water, pipe insulation and various construction materials to the environment. Consolidated Edison Co. of New York, Inc. (Con Edison) and LPI (Lucius Pitkin, Inc.) investigated the event. Based on detailed metallurgical and engineering evaluations of the steam system configuration and operating conditions, it was concluded that the steam pipe ruptured as a result of excessive pressure caused by condensation-induced waterhammer. This paper presents a summary of the engineering evaluation, root cause, and conditions leading to the pipe rupture and provides measures which can be taken to reduce the likelihood of such a failure and enhance public safety.

Inspections of Tread Damaged Wheelsets

2008 ◽  
Author(s):  
Scott M. Cummings ◽  
Don Lauro
Keyword(s):  
Impact Load ◽  
Damage Mechanism ◽  
Location Data ◽  
Root Cause ◽  
Frequent Use ◽  
Crack Band ◽  
Defect Prevention ◽  
Research Consortium ◽  
High Level ◽  
Contact Position

Inspections of 163 wheelsets conducted by the Wheel Defect Prevention Research Consortium (WDPRC) have produced critical information in identifying the high-level root causes of tread damage. While the overall wheel tread damage problem appears to be split fairly evenly between shelling and spalling, the type of tread damage on a wheelset is strongly linked to the type of car from which it was removed. Coal car wheels, which generally run in heavy axle load, high-mileage service with minimal yard handling, are almost exclusively subject to shelling damage with little spalling damage. On the other hand, mixed freight cars, such as tank cars and covered hopper cars, tend to run in lower mileage service with more yard handling, resulting in fewer loading cycles under lighter stress and more frequent use of hand brakes. Not surprisingly then, wheels from these types of cars were observed to have a mix of spalling and shelling damage, with spalling being the predominant damage mechanism. Nearly every high impact wheel (HIW) inspected showed either spalling, shelling, or some combination of the two. As expected, wheel impact load detector (WILD) readings and radial tread run out data were found to be related. Rim thickness deviations and rim lateral face deviations were not found to be important contributors to shelling. The lateral tread location of radial run-out deviations and crack bands could be an important clue in discovering the root cause of shelling. Radial run-out data and crack band location data shows that shelling damage is most prevalent outboard of the tapeline. This is the expected wheel/rail contact position of a wheel in the lead wheelset position of a truck, while riding on the low (inside) rail of a curve. Many of the wheels that were removed for wear causes were found to have noncondemnable shelling and spalling, indicating that tread damage is more prevalent than repair records would indicate.

Overview of Impacts of Distribution Generations and Micro Grids on Active Distribution Network Operation

2014 ◽  
Vol 700 ◽  
pp. 103-110
Author(s):  
Lei Yu ◽  
Tian Yang Zhao ◽  
Xu Wu ◽  
Jian Hua Zhang
Keyword(s):  
Distribution System ◽  
Dynamic Models ◽  
Control Method ◽  
Distribution Network ◽  
Distribution Networks ◽  
Negative Effects ◽  
Active Distribution Network ◽  
System Operator ◽  
Network Operation ◽  
High Level

With recent development of technology and management in power market and equipment, more and more distributed generation (DG) is embedded in the distribution network. However the approach of connecting DG in most cases is based on a so-called ‘fit and forget’ policy and the capacity of DG is limited rigidly by distribution system operator to avoid the negative effects of high level penetration. New management technologies have been proposed to handle the integration of DGs in the distribution networks. In this review, the micro grid (MG) was treated as the local control method to coordinate DGs within a small area of distribution network. And the active distribution network (AND) was treated as the global control mechanism to actively manage DGs, MGs and other equipment. The operation framework of ADN was firstly introduced. Then based on the static and dynamic models of DGs and MGs, impacts of DGs and MGs on the ADN are surveyed from power quality, stability to the operation. Finally, the conclusion and suggestion is given in this paper.

scholarly journals Problems and Prospects for the Development of the Municipal Infrastructure Management System in the Russian Federation

2021 ◽  
pp. 80-93
Author(s):  
S. L. Katanandov ◽  
A. Yu. Demin
Keyword(s):  
Local Governments ◽  
National Development ◽  
Infrastructure Management ◽  
Root Cause ◽  
Russian Federa Tion ◽  
Wear And Tear ◽  
The Russian Federation ◽  
High Level ◽  
Infrastructure Services

In modern conditions, the solution of the national development tasks of the Russian Federa-tion, aimed primarily at ensuring the high level and quality of life of the population, is constrained by the inefficiency of the functioning of communal infrastructure systems. The high wear and tear of its networks and facilities, as well as the lack of effective management, pose many challenges. The root cause of these problems is in a contradictory system of government, in which municipal authorities, most interested (by their nature) in solving them, are deprived of the necessary resources and opportunities for making effective decisions. The preservation of the situation may lead in the medium term to significant budgetary costs for the restoration of serviceability and the development of communal infrastructure against the background of a further decrease in the quality of infrastructure services. There was a need to change the approach to addressing the problems. The article proposes this kind of approach, based on the redistribution of powers and giving local governments real opportunities to influence the management of communal infrastructure.

Sign in / Sign up

Export Citation Format

Share Document