Piping Costs Research Articles

Performance analyses of LP and MILP solvers based on newly introduced scale: Case studies of water network problems in chemical processes

To meet fresh water requirement as well as to tackle wastewater generation are serious issues in process industries in the present scenario. To deal with water network problems, various models and computer aided tools have been used. GAMS software is used for this purpose since many years. All kind of water network models including LP, NLP, MILP and MINLP are extensively solved by this tool. However, it appears that no specific work is available in literature to observe the behaviour of different solvers on industrial case studies. The present study addresses this gap through behaviour analysis of LP and MILP solvers. Four case studies are considered from open literature, which include water networks for single contaminant, multi-contaminant and process as well as treatment units. LP models of all cases are solved through three different solvers i.e. CPLEX, CONOPT and MINOS. Further, piping cost is incorporated into LP models and thus, converted these to MILP, which are solved using three solvers such as BDMLP, CBC and SCIP. Results obtained through six solvers are compared at BECOTA scale. MINOS performs better for LP models as compared to CPLEX- a traditionally used LP solver. However, CBC is better amongst other MILP solvers considered. It is observed that selection of a particular solver may significantly influence the water network design as well as plant economy. Hence, selection of solvers should be carried out carefully.

Calculating the Economic Level of Friction in Pressurized Water Systems

In this paper, an algebraic expression is presented to determine the optimum hydraulic gradient (J0) in a pressurized water system. J0 represents the economic level of friction losses (ELF), which is dependent on the network’s behavior as well as other parameters, including energy and the pipe costs. As these have prices changed over time, so has the value of J0. The network-related parameter was obtained from the total costs function and the sum of the operational and capital expenditures. Because these costs exhibited an opposite trend from J, a minimum total cost exists, specifically, J0. The algebraic expression, which was derived from the mathematical model of the network, was first calculated for the network’s steady state flow and was later generalized for application to a dynamic one. For a network operating in a given context, J0 was fairly stable in terms of dynamic flow variations, providing valuable information. The first piece of information was the ELF itself, which indicated the energy efficiency of the system from the perspective of friction loss. The second indicated which pipes required renewal from a similar perspective. Thirdly, it provided a simple criterion to calculate the diameter of new pipes. Finally, as J0 can be easily updated, when predictions are performed at the network’s designed time fail (e.g., growing urban trends, demand evolution, etc.), decisions can also be updated.

A thermo-economic approach for determination of optimum thickness of thermal insulation applied to piping systems

In the present work, the exergetic cost, exergy losses, and optimum insulation thicknesses of pipes by the usage of thermoeconomic analysis are found for the selected four cities, each with different climate regions in Turkey. Glasswool, EPS, and XPS are selected as the insulation materials in this work. It is seen that the optimum value of the insulation thickness such as exergetic cost and exergy losses is dependent on degree-days and it increases with the increasing degree-days. With natural gas as a fuel type and XPS as an insulation material, the optimum values of insulation thicknesses are found to be 0.019, 0.030, 0.036, and 0.057 m for Aydın, Tekirdağ, Elazığ, and Kars, respectively. The exergy savings and payback periods increase with the increasing pipe diameters. Additionally, the optimum insulation thickness is dependent on the convective heat transfer coefficient on the outer surface of the pipe, and it increases with the increasing convective heat transfer coefficient. It is seen from the results of sensitivity analysis that the sensitivity degree of increase in the discount and inflation rate is greater than other variations with respect to the optimum insulation thickness.

Effect of different dripper discharge, spacing and lateral spacing on drip irri-gated green bean yield and quality parameters

Experiments were conducted to assess the effects of different dripper discharges, dripper spacings and lateral spacings on yield and physical quality attributes of drip-irrigated green beans. Three different drip irrigation system were arranges as: DS1: dripper discharge is 2 L h ‒1 , dripper spacings is 33 cm and lateral spacings is 50 cm (a lateral line for each plant row); DS2: dripper discharge is 2 L h ‒1 , dripper spacings is 33 cm and lateral spacings is 100 cm (a lateral line for two plant rows); DS3: dripper discharge is 4 L h ‒1 , dripper spacings is 50 cm and lateral spacings is 100 cm (a lateral line for two plant rows). In irrigations, wetted area percentage was taken as 75%. Present findings revealed that different drip irrigation treatments did not have significant effects on yield and physical quality attributes of green beans. Therefore, it was concluded that lateral spacing in drip irrigation of greenbeans could be selected as 100 cm (a lateral line for two plant rows). This will bring at least 50% saving in lateral pipe costs of drip irrigation systems.

China’s national demonstration project achieves around 50% net efficiency with 600 °C class materials

The bottlenecks in developing high-efficiency ultra-super critical (USC) coal power technology are analyzed within the context of the growing pressure on the coal power industry to reduce carbon dioxide (CO2) emissions. To meet these demands, further improving the annual average operating efficiency of coal power is essential. A cross-compound double reheat unit design characterized by an elevated and conventional turbine layout is proposed in this paper. This new design can greatly shorten the length of expensive high-temperature piping required, significantly cut piping costs as well as reducing pressure drops and heat losses, resulting in a much higher efficiency and performance-price ratio than conventional double reheat design. The engineering study demonstrates the feasibility and advantages of this design. Now this new design is being implemented on Pingshan Phase II Project as a demonstration coal power unit in China. Despite the new turbine arrangement, Pingshan Phase II Project also adopts a series of energy saving, environmental protection, efficiency preservation and safety technologies, of which some have already gained success in Shanghai Waigaoqiao No. 3 Power Plant. Based on the new design and further optimization, the unit net efficiency of Pingshan Phase II is expected to achieve 49.8% under rated conditions on a lower heating value (LHV) basis. Combined with a series of innovative technologies that can keep the efficiency from decreasing under operational conditions, the annual average net efficiency can achieve 48.8% on LHV basis. This efficiency level is high enough to meet the strict CO2 emission standard proposed by United States Environment Protection Agency (U.S. EPA) based on the Pittsburgh #8 bituminous coal, showing significant potential for reducing CO2 emissions. A series of low-energy-consumption and even energy-saving pollutants removal technologies are also be applied on this project to harmonize high efficiency and low emissions.

Evaluation of Excess Heat Utilization in District Heating Systems by Implementing Levelized Cost of Excess Heat

District heating plays a key role in achieving high primary energy savings and the reduction of the overall environmental impact of the energy sector. This was recently recognized by the European Commission, which emphasizes the importance of these systems, especially when integrated with renewable energy sources, like solar, biomass, geothermal, etc. On the other hand, high amounts of heat are currently being wasted in the industry sector, which causes low energy efficiency of these processes. This excess heat can be utilized and transported to the final customer by a distribution network. The main goal of this research was to calculate the potential for excess heat utilization in district heating systems by implementing the levelized cost of excess heat method. Additionally, this paper proves the economic and environmental benefits of switching from individual heating solutions to a district heating system. This was done by using the QGIS software. The variation of different relevant parameters was taken into account in the sensitivity analysis. Therefore, the final result was the determination of the maximum potential distance of the excess heat source from the demand, for different available heat supplies, costs of pipes, and excess heat prices.

Optimization of multi-plants cooling water system

Conventionally, cooling water system is optimized within a single plant. In reality, a set of cooling towers supply water for multiple plants. This paper presents an optimization model for multi-plants cooling water system. Instead of using a set of uniform pumps to transport cooling water, this work proposed a novel multi-loops pump network and an updated main-auxiliary pump network to reduce pumping energy. Distance factors and pipeline layouts are considered owing to the long distance between plants and pump station. Connecting patterns of different pump networks are investigated and corresponding piping costs are treated as optimized variables. Cooler and pump networks, cooling tower and pipeline layouts are optimized simultaneously. The model is formulated as a mixed-integer nonlinear programming (MINLP) problem. The objective is to obtain the cooling water system with minimized total annual cost. Two case studies are used to illustrate the effectiveness of the proposed structure.

Analysis and Improvement of Material Selection for Process Piping System in Offshore Industry

Material failure mainly because of corrosion is a highly dangerous and expensive phenomenon in the offshore sector of the oil and gas industry, associated with severe negative consequences such as loss of asset, loss of production due to plant shutdown, loss of human life, and health, safety, and environment (HSE) problems (e.g. environmental pollution). Additionally, piping systems are produced in large numbers for the topside facilities in the oil and gas plants. Thus, the main aim of this paper is to introduce a novel approach for the piping material selection in the offshore industry to minimize the risk of piping corrosion and weight reduction with an optimum cost. The central focus of the study is to develop a material selection tool based on a systematic material selection approach and the existing literature, standards, and specifications. In this study, the optimal material selection strategy includes three well-known methods of screening: Cambridge material selector, value engineering (VE), and technique for order preference by similarity to ideal solution (TOPSIS). The proposed guideline is a practical reference for material and piping engineers in the offshore industry to select the best choice of material for a specific application. The main finding of this research is that 25% chromium super duplex stainless steel is the best choice of material for processing piping systems in offshore plants for non-sour process (hydrocarbon) services. Super duplex stainless steel provides a high corrosion resistance and mechanical strength with the advantage of weight reduction for the selected facilities. A method of piping cost analysis is introduced to validate super duplex stainless steel as the most economical option.

Methodical approach to determination of costs at the initial stages of the project research of gas-supply systems

The article deals with topical issues at the pre-investment stage of project design to justify decisions on the feasibility of further investment and the transition to the next stage of design - the development of project documentation. At the pre-project stage, there is often a situation when the parameters of structures have not yet been determined, and capital investments must be evaluated. Methodological approaches to determining the cost of gasification facilities and the estimated model of cost calculations at the stage of investment justification with the help of enlarged indicators that improve the accuracy and validity of calculations at the stage of pre-design studies are substantiated. It is shown that the enlarged indicators used at the stage of investment justification form the regulatory basis for determining the cost of gasification facilities, for estimating capital costs, as well as for evaluating the effectiveness of investments in the selection of project options. The object of the study adopted electrically welded steel pipes and polyethylene pipes for gas pipelines. Evaluation and forecasting of the cost of gas distribution systems in the article are proposed using regression models depending on time and diameter of the pipe. The regression dependences of the cost of steel and polyethylene pipes of all standard sizes and confidence intervals for the cost of pipes allow to estimate also possible errors of the forecast cost estimation.

A new approach to hydraulic calculations of free-flow drainage systems

The accuracy of hydraulic calculations is determined by the accuracy of the mathematical models inherent in their foundation. The results of calculations, obtained by different models, and differing from each other by 5-10% is considered identical. The present study examines classical ways of finding the Chezy formula that are used for calculations of free-flow pipelines. These formulas differ from each other not only in parameters but also in the form of the functional dependence. The equation, underlying the hydraulic calculations, is nonlinear. Its solution is possible only in the number of well-established methods. It offers numerical computing to find pipelines diameters and their filling, as well as the algorithm to realize it. It conducts numerical experiment to compare pipelines diameters and filling and flow velocities. It presents frequency characteristics to distribute the parameters under analysis. For a specific example, the difference of cost of pipes, the diameters of which was found using the various formulas for coefficient Chezy, was calculated.

A new approach to hydraulic calculations of free-flow drainage systems

The accuracy of hydraulic calculations is determined by the accuracy of the mathematical models inherent in their foundation. The results of calculations, obtained by different models, and differing from each other by 5-10% is considered identical. The present study examines classical ways of finding the Chezy formula that are used for calculations of free-flow pipelines. These formulas differ from each other not only in parameters but also in the form of the functional dependence. The equation, underlying the hydraulic calculations, is nonlinear. Its solution is possible only in the number of well-established methods. It offers numerical computing to find pipelines diameters and their filling, as well as the algorithm to realize it. It conducts numerical experiment to compare pipelines diameters and filling and flow velocities. It presents frequency characteristics to distribute the parameters under analysis. For a specific example, the difference of cost of pipes, the diameters of which was found using the various formulas for coefficient Chezy, was calculated.

Analysis of floating house platform stability using polyvinyl chloride (PVC) pipe material

The high demand for land to be built on, makes the price of land more expensive. Various efforts were made to get land to build houses on, one of them was by way of coastal reclamation. The pond area initially functioned as a water catchment area, but later became new land through the reclamation process. This will have adverse impacts on the environment such as flooding due to lack of water storage. To overcome the problem of building in the coastal area without reclaiming, is using floating house. A floating house is a building structure that floats on the water surface by leaning to drowned area weight as the weight parameter which the structure could handle. This research is done to analyze the material platform. PVC pipe is used with floating force (Fa) parameter and cost plan analysis. The structure weight analysis total result is 555,887.5 Newton. The floating force of structure platform is 648.792 Newton. The connection system is a bolt connection system that us 3 cm in diameter with an anchor of length 22 cm, and a total of 4 bolts on each connection. Cost plan analysis using PVC pipe costs IDR 379.500.000,00.

DESIGN OF PLUMBING SYSTEM AT TUNJUNGAN PLAZA APARTMENT, SURABAYA

Aim: This study of plumbing system plan is aimed at planning a plumbing system that is compatible with clean water, waste water and rain water management at Tunjungan Plaza apartment, Surabaya City, Indonesia according to SNI 8153-2015, and meet 5 aspects of safety, security, simplicity, beauty, and economy. It applies water supply system which commonly used for tall buildings, namely Roof Tank system. Methodology and Result: Plumbing system planning methods are collecting and analyzing fluctuation in water use, planning clean water and recycled water systems by endorsing alternative piping for clean water and recycled water. In addition to water supply, recycled water system that utilizes waste water to be recycled for flushing closets and watering plants also required to be implemented. Average daily water consumption is 268 m3/day for clean water and 44 m3/day for recycled water with the capacity of ground water tank for clean water is 564.54 m3 and recycled water is 62 m3. Conclusion, significance and impact study: Clean water supply system will implement roof tank system and recycled water will reutilize wastewater for flushing on toilet tank and watering the plants. Waste water use separated system between grey water and black water and then distributed to STP to be treated and reused for flushing water closet and watering plants. Rain water goes to infiltration well by gravity through designed 1 well. Total amount of investment of plumbing equipment is Rp 2,157,697,501,- with cost of water supply per unit Rp 4,445,643,- meanwhile waste water piping cost per units is Rp 1,070,711,-.

A Comparison of Utility Heat Exchanger Network Synthesis for Total Site Heat Integration Methods

This paper compares Utility Heat Exchanger Network (UEN) design between two Total Site Heat Integration (TSHI) methods, the Conventional Total Site Targeting method (CTST) and the recently developed Unified Total Site Targeting (UTST) method. A large Kraft Pulp Mill plant has been chosen as a case study. Total Site targets have been calculated using a ExcelTM targeting spreadsheet and networks have been designed with the help of SupertagetTM for both the CTST and UTST methods. To achieve heat recovery and utility targets, both series and parallel utility heat exchanger matches for non-isothermal utilities are allowed in the CTST method, while series matches are allowed in the UTST method if the heat exchangers in series are from the same process. Series matches based on CTST method may create a dependency on two or more separate processes, which operational and control issues may occur, higher piping costs may be imposed, and utility target temperatures may not be achieved in the consecutive processes if one or more processes were to be out of service. Relaxation of the network can resolve these issues for the CTST method; however, if the relaxation occurs on the side of the utility loop that constrains heat recovery, the net heat recovery targets may not be achieved within the Total Site. The UTST method with its modified targeting procedure may offer slightly lower heat recovery targets but with simpler UEN design compared to CTST method are more realistic and achievable. Finally, after UEN design, non-isothermal utility loops need to be balanced in terms of mass and energy for both methods.

Total site centralised water integration for efficient industrial site water minimisation

Water is used in process industry for a wide range of applications. Water minimisation has received growing attention due to stricter environmental regulations and scarcity of quality water. Rising price of fresh water and cost of wastewater treatment, as well as the relation with the energy (generating emissions) needed for preparing and supplying water, have created an urgent need for efficient water utilisation, especially in the industrial sector. Demand for clean water has been rapidly growing also in the commercial and domestic sector, and very substantially in the agricultural sector. In some regions, water has become a strategic commodity that is even more important than energy. Numerous research works have been performed on Total Site Water Integration (also known as Interplant Water Integration in some papers). However, a superstructure that considers all possibilities of water exchange among sources and demands in industrial sites or a region, are practically challenging to implement since most plants prefer to keep their data and processes confidential. The cost of piping and pumping can be very high due to the need to transfer water across complex industrial water networks. In this study, the option of using centralised headers managed by a third party is explored for a simpler and easy to manage water reuse and recycling among plants. Two centralised water reuse headers with different wastewater quality range, located along a set of plants are proposed. A new Pinch Analysis methodology known as Total Site Centralised Water Integration (TS-CWI) to target the minimum freshwater requirement and wastewater generated resulted from the integration of plants with this centralised water reuse headers are presented. The methodology is illustrated with a case study with 55.1 % of reduction of freshwater requirement and 54.7 % of reduction of wastewater generated.

An industrial area layout design methodology considering piping and safety using genetic algorithm

The industrial area layout can influence the economic benefit, safety and surrounding environment of an industrial area to a large extent, especially the length of piping and safety. Every year, the construction of new industrial areas requires thousands of tons of steel pipes, resulting in a high consumption of natural resource of iron and high emission of carbon dioxide. Additionally, the long pipeline will increase the energy consumption for material transportation. Meanwhile, accidents in industrial areas can usually result in serious damage to the local environment. So the optimization of industrial area layout holds great significance for natural resource, energy saving, and environment protection. But up to now, very few papers have been reported to consider the use of pipes and safety simultaneously to optimize the layout in industrial area level. Most works only focus on safety aspects, and the impact of connection is ignored. Accordingly, this paper proposes a methodology to optimize the relative position of each plant, whose objective function consists of piping cost and safety cost. In this paper, despite conventional consideration of material piping, steam piping, which features multiple-branches connected pipeline network, is also considered. For safety issues, it is firstly analyzed by qualitative principles to limit position for some specified plants. Then quantitative analysis, including explosion and toxic release, are optimized simultaneously with connection cost. A genetic algorithm is used to solve the proposed model. Kruskal algorithm and Arrangement & Combination are used to calculate the length of steam piping. Finally, a case study illustrates the effectiveness and applicability of the proposed methodology.

Thermal performance of a selected heat pipe at different tilt angles

An attempt is made to design, fabricate and test a copper heat pipe with 12 mm diameter, 300mm length and thickness of 1mm with a heat input of 7.29W. Experiments were conducted with and without working fluid for different inclinations to assess the thermal performance of heat pipe. The working fluids chosen for the study are acetone and distilled water and are compared. The thermal performance of the heat pipe was quantified in terms of thermal resistance and overall heat transfer coefficient by measuring temperature distribution across the heat pipe. The heat pipe was aligned for different inclinations and an optimum tilt angle was found experimentally, validated the same with simulation result obtained by computational fluid dynamics analysis and also with a reference paper. The copper heat pipe is found to be effective when acetone is used as working fluid. The optimum inclination angle of heat pipe for maximum rate of heat transfer is found to be 60° for both the working fluids tested. Even the cost of the heat pipe fabricated is very less compared to the commercial heat pipes available in the market.

DESIGN OF SPRINKLER IRRIGATION TAPERED MAIN LINE BY LINEAR PROGRAMMING

A mathematical linear programming model based on Microsoft Excel spreadsheet was developed to design mainline of sprinkler irrigation system. The line considered has a length of 522 m combined with five different nominal diameters of 3', 3-1/2, 4, 5 and (internal diameter of 73.7, 85.4, 97.2, 122.3and 149.3 mm) which are commercially available in the Egyptian markets. The objective function was to minimize the cost of the mainline pipe; and the constraints considered were commercial availability of diameters. The head loss calculations are based on four different head loss formulas. These are the Hazen-Williams, Manning, Scobey, and Darcy-Weisbach equations. The model estimates the number of pipe unit according to the available manufacturer length. ( taken as 6 meter long). The lowest cost of 7924 US$ was found by the Darcy Wiesbach equation followed by Manning as 8030, Hazen–Williams as 8051 and Scobey as 8385. Validity and sensitivity of the model were confirmed. The effect of land slope and inlet pressure to the system was studied. The results indicated that increasing in inlet pressure decreases the cost of the mainline. Meanwhile, the cost of the mainline is proportionally increased by increasing the up slope of the land, and inversely increases by increasing the down slope of the land.

Resilience-based optimal design of water distribution network

Optimal design of water distribution network is generally aimed to minimize the capital cost of the investments on tanks, pipes, pumps, and other appurtenances. Minimizing the cost of pipes is usually considered as a prime objective as its proportion in capital cost of the water distribution system project is very high. However, minimizing the capital cost of the pipeline alone may result in economical network configuration, but it may not be a promising solution in terms of resilience point of view. Resilience of the water distribution network has been considered as one of the popular surrogate measures to address ability of network to withstand failure scenarios. To improve the resiliency of the network, the pipe network optimization can be performed with two objectives, namely minimizing the capital cost as first objective and maximizing resilience measure of the configuration as secondary objective. In the present work, these two objectives are combined as single objective and optimization problem is solved by differential evolution technique. The paper illustrates the procedure for normalizing the objective functions having distinct metrics. Two of the existing resilience indices and power efficiency are considered for optimal design of water distribution network. The proposed normalized objective function is found to be efficient under weighted method of handling multi-objective water distribution design problem. The numerical results of the design indicate the importance of sizing pipe telescopically along shortest path of flow to have enhanced resiliency indices.

Synthesis Of Mass Exchanger Network Considering Piping And Pumping Costs Using Process Integration Principles

This paper presents a procedure to optimize mass exchanger network considering piping and pumping costs. This optimization technique is based on the combination of Pinch technology with mathematical programming approach to obtain the optimum minimum allowable composition difference (e) value. In the present work three examples are taken from open literature to study the contribution and effect of piping and pumping costs on optimum e value and mass exchanger network design. The results obtained for Examples 1, 2 and 3 shows that e changes from specified to optimized e value with improved network configuration before considering piping and pumping costs. After accounting piping and pumping costs e changes from optimized to new optimized e value with the changes of network configuration. Further, based on results of Examples 1, 2 and 3 it is found that piping and pumping costs contributes around 12% and 3% towards TAC of a mass exchanger network.