Pressure Utilization in Water Transmission Pipelines in Alain Region Considering Transient Conditions

The residual pressure energy available in water transmission pipelines can be easily utilized via direct connection to the distribution system and bypassing the storage reservoirs and booster pumping stations. This thesis investigates the feasibility of bypassing a number of reservoirs and pumping stations in a small transmission system in AlAin City of United Arab Emirates. The system has a major transmission pumping station (AlAin Reception Pumping Station, or \u27AARS\u27) that hosts four fixed-speed pumps, a main 1200mm line, storage reservoirs and boosting pumps at three zones (Dahma, Markhania and Maqam), besides few other connection pipes. The system also has three surge vessels and air valves. The objective of the study has been achieved by conducting a comprehensive transient analysis to evaluate the potential of pressure rises associated with various operating scenarios. Such scenarios were divided into normal and abnormal operating conditions. The normal operating conditions are related to the typical water supply changes occurring during any typical day. The abnormal operating conditions represent rare and odd operating scenarios such as sudden valve closures/openings and pump trips. Limiting pressure heads of 160 m for the pipe pressure rating and 60 m for the pump shutoff head were considered to identify safe performance of the proposed bypass setting. British Standards (BS), International Standard Organization (ISO) and Abu Dhabi Water and Electricity Authority (ADWEA) Standards are adapted for the design of pipes and fittings. Simulation results associated with the normal operating conditions indicated that the proposed setting is safely performing in such conditions and has yielded safe closure times for different valves. Results of the abnormal operating conditions indicated unsafe performance in the case of sudden valve closures. To protect the system against severe transient pressures under these conditions, remedial measures are proposed. Pressure relief valves should be installed on the branches at the upstream side of the distribution network. The proposed valves are sized and evaluated when the system pressure is maintained below 100 m. The savings in energy cost associated with the proposed bypass setting is estimated about $ 850,000 per year. Such savings are found to be available after a payback period of one year and one month to cover the capital cost of the needed bypasses and pressure relief valves

Burst detection and location in water transmission pipelines

This paper presents results from testing of a burst detection and location technique on a water transmission pipeline. The primary targets of the method are medium and large bursts that are the result of a sudden rupture of a pipe wall or other physical element in the pipeline system. The technique is based on the continuous monitoring of the pressure in the pipeline combined with a hydraulic transient modeling. Analysis of a burst-induced pressure transient wave and its reflections from the pipeline boundaries is used to derive the location and size of the burst. The method has earlier demonstrated promising results on a laboratory pipeline and a dead-end branch of a real water distribution network. Results presented here show that the approach has a potential to be used for burst detection and location in long transmission pipelines. Bursts of different sizes, locations and opening times were successfully detected and located. Different operational regimes of the pipeline were considered. The technique could help to minimize the response time to the pipe failure and therefore reduce the losses associated with a burst and improve reliability of the pipeline operation. © copyright ASCE 2005

Valve Location Method for Evaluating Drain Efficiency in Water Transmission Pipelines

Water transmission pipelines, which transport bulk water into storage facilities, usually have a tree-type configuration with large dimensions; thus, the breakage of a pipeline may cause a catastrophic service interruption to customers. Although drain efficiency is closely related to the number of washout and control valves and their locations, there is no useful guideline. This paper proposes a valve locating method by introducing numerical analyses to enumerate drainage time and zone. A time integration method, combined with the Newton–Raphson algorithm, is suggested to resolve drainage time, while considering the friction loss in gravitational flow. A drain direction matrix, which shows drain direction and coverage, is derived using a network searching algorithm. Furthermore, a feasible practical approach is presented by introducing a critical horizontal slope, a major washout valve, drainage indices, and control valve embedment. The developed method is first applied to simple pipes to validate the drainage time module. Subsequently, the model is expanded to the CY transmission line, which is one of the BR water supply systems in South Korea currently in operation. The results reveal that three drain valve locations have been neglected, and the addition of control valves guarantees consistent drain time below the operational criteria. Document type: Articl

Decision-making tool for structural integrity assessment of buried water-transmission mains using a geomechanical approach

Uncertainties and spatial variability of the soil are considered in a geomechanical approach of water-transmission pipelines. This enables to go further than the standard cross-sectional design of the pipe. A hybrid model, which is a mixture of a cross-sectional model and a longitudinal model, was developed. This model assesses the failure modes of the pipe and provides the critical indicators of its current state of performance as well as a prognosis at a longer time

Flow regime identification for air valves failure evaluation in water pipelines using pressure data

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordAir valve failure can cause air accumulation and result in a loss of carrying capacity, pipe vibration and even in some situations a catastrophic failure of water transmission pipelines. Air is most likely to accumulate in downward sloping pipes, leading to flow regime transition in these pipes. The flow regime identification can be used for fault diagnosis of air valves, but has received little attention in previous research. This paper develops a flow regime identification method that is based on support vector machines (SVMs) to evaluate the operational state of air valves in freshwater/potable pipelines using pressure signals. The laboratory experiments are set up to collect pressure data with respect to the four common flow regimes: bubbly flow, plug flow, blow-back flow and stratified flow. Two SVMs are constructed to identify bubbly and plug flows and validated based on the collected pressure data. The results demonstrate that pressure signals can be used for identifying flow regimes that represent the operational state (functioning or malfunctioning) of air valves. Among several signal features, Power Spectral Density and Short-Zero Crossing Rate are found to be the best indictors to classify flow regimes by SVMs. The sampling rate and time of pressure signals have significant influence on the performance of SVM classification. With optimal SVM features and pressure sampling parameters the identification accuracies exceeded 93% in the test cases. The findings of this study show that the SVM flow regime identification is a promising methodology for fault diagnosis of air valve failure in water pipelines.National Natural Science Foundation of Chin

Cost Analysis of Implementing In-Pipe Hydro Turbine in the United Arab Emirates Water Network

Water transmission lines have potential reserved energy, which is usually lost. Therefore, targeting this clean energy to produce electricity to power up the auxiliaries and utilities of water plants or consumers is financially and environmentally beneficial. This paper aims to investigate the feasibility of installing an inline hydropower system in an existing transmission water pipe. It analyzes the feasibility of implementing a mini-hydropower plant in the transmission line of Liwa’s reservoir in the UAE. The maximum possible power harvested is 218.175 kW at the given water flow rate and net head. The payback period and the return on investment are analyzed based on different scenarios related to capital investment, operation, maintenance cost, and plant capacity factor. It is found that the payback period ranges between one to six years, where the return on investment can be as high as 85%. Furthermore, the expected CO2 emissions saving for this project is calculated to be between 395 and 1939 tons per year

Pipeline break detection using pressure transient monitoring

Sudden pipe breaks occur in water transmission pipelines and distribution mains. The consequences of these breaks can be very expensive because of the service interruption, the cost of repair, and damage to surrounding property and infrastructure. The costs associated with the pipeline breaks can be reduced by minimizing the break detection and location time. This paper presents a new continuous monitoring approach for detecting and locating breaks in pipelines. A sudden pipe break creates a negative pressure wave that travels in both directions away from the break point and is reflected at the pipeline boundaries. Using the pressure data measured at one location along the pipeline, the timing of the initial and reflected transient waves induced by the break determines the location of the break. The magnitude of the transient wave provides an estimate of the break size. The continuous monitoring technique uses a modified two-sided cumulative sum (CUSUM) algorithm to detect abrupt break-induced changes in the pressure data. The adaptive tuning of CUSUM parameters is implemented to detect breaks of differing sizes and opening times. The continuous monitoring technique is verified by using results from both laboratory and field experiments and shows potential for detecting and locating sudden breaks in real pipelines.Dalius Misiunas, John Vítkovský, Gustaf Olsson, Angus Simpson, M.ASCE, and Martin Lambert

LUCIDPIPE™ POWER SYSTEM

In most gravity fed water transmission pipelines, it is desired to reduce excess pressure head to prevent undue strain on a pipeline and lower the incidence of leaks. Normally this is done with pressure reducing valves that essentially burn off this excess pressure as heat. The LucidPipe™ system converts it to low cost electricity thereby removing unwanted pressure and generating energy at the same time - energy that can be put used behind the grid or put back on the grid. The LucidPipe™ system extracts a small percentage of pressure head providing nearly invisible operation allowing water operators to fulfill their primary mission of delivering water to consumers. Because the LucidPipe™ system extracts only a small percentage of pressure head when operating, and about 1 psi of pressure head when stopped, it is virtually invisible in a pipe network and can be placed directly in-line without the need of a bypass for the turbine. Traditional hydropower turbines effectively halt the flow of water when stopped, and can cause dangerous water hammer when grid power is disconnected so they must be placed in a bypass to not interrupt the safe delivery of water. Also, traditional hydropower turbines operate in a narrow band of pressures and flows whereas the LucidPipe™ system has a wide operating range typically found in municipal water transmission system. The LucidPipe™ system adjusts to meet the demands of water delivery rather than a water operator having to adjust the water to meet the demands of the turbine

Purdue ECT Report - Fourth Quarter 2016

Fourth Quarter 2016 This is a quarterly report from the Purdue ECT

Quality Meets Quantity: San Gabriel Valley, California: The Metropolitan Water District of Southern California Proposal

19 pages (includes illustrations and maps). Contains footnotes