Header Pipe Research Articles

RESEARCH OF WELLHEAD CHRISTMAS TREE

The article provides information about fountain nozzles, the fountain valve as one of the key equipment for exploiting well products, its applications, the main components including the pipe header, xmas tree and other parts. It also notes the parts exposed to corrosive effects of the well product and provides information about the solution method. Keywords: Christmas tree, valve, pipe head, sealing, fountain well.

Preliminary accident analyses of in-vessel LOCA for the chinese fusion test reactor HCCB blanket concept

For the helium-cooled ceramic breeder (HCCB) blanket concept improved in 2018 and the primary heat transfer system following China Fusion Engineering Test Reactor (CFETR) in 2019, an in-vessel loss of coolant accident (LOCA) has been investigated with the assumption of a break of the first wall (FW) coolant channels and a double-ended guillotine break of a helium cooling system (HCS) pipe in vacuum vessel (VV). The break leads to helium inject into the VV. After the accident occurs, the helium release leads a plasma disruption and pressure increase in the VV. This paper presents the analysis results of the in-vessel LOCA accidents in CFETR and gives the accident sequence compare with the break in the FW and header pipe. The accident analysis and influence compares can provide a reference for the iterative design.

Optimized Design of Pipe Elbows for Erosion Wear

Multiphase flows are widely used to transport solid–liquid mixtures in oil and gas fields. The pipeline structures used can suffer damage from the high-pressure sand-carrying fracturing fluid, causing erosion and wear failures in the engineering field. In this work, an erosion model that considers particle turbulent kinetic energy and the effect of the design’s structural parameters on the erosion wear of spatial pipe structures is established using computational fluid dynamics (CFD). Structural parameters such as the bending diameter ratio, bending angle and spatial angle are discussed, and the location and degree of each parameter with regard to the erosion rate are obtained. The results show that the included angle of the pipe elbow has the greatest influence on erosion wear among the structural parameters. Several typical anti-erosion optimization models are compared and analysed, and a corrugated anti-erosion structure based on a bionic structure is further proposed. It is found that the anti-erosion performance of the T-type blind long header pipe is better in terms of the numerical value of the erosion rate, while for the erosion cloud diagram, the anti-erosion performance of the corrugated structure is superior. Finally, some suggestions for the application of the anti-erosion structure in the engineering field are given, and technical support is provided for the anti-erosion structure design and practical application of space pipeline systems in the future.

Energy potential assessment and techno–economic analysis of micro hydro–photovoltaic hybrid system in Goda Warke village, Ethiopia

Abstract Rural Ethiopia has significant untapped potential for hydro and solar energy generation systems. However, challenges arise from seasonal variations and unfavourable topographic positions of flowing rivers, hindering the efficient exploitation of these resources. Despite the country’s abundance in hydro and solar energy resources, >75% of the population still lack access to electricity from the national grid. This work deals with energy resource potential assessment and techno–economic analysis of micro hydro–photovoltaic (PV) hybrid systems, considered in the case study of Goda Warke village, located in the Yaya Gulele district. A novel framework is proposed that utilizes the Natural Resource Soil Conservation Service curve number method to assess the energy potential of micro-hydro energy in ungauged basins, specifically at the exit point of the Girar River basin catchment. The average monthly flow rate in the basin is 0.975 m3/s, while the area exhibits a solar radiation potential of 5.39 kWh/m2/day. Energy policy promotes expanding access to modern energy sources and utilization of indigenous energy resources. Simulation results indicate that the hydro/PV/diesel generator (DG)/battery and hydro/PV/battery systems are the most optimal choices based on net present cost, with the inclusion of a DG for economic comparison. Micro-hydro energy covers most of the electric load in the area, achieving a capacity factor of 47.5%. The cost of energy and net present cost were found to be sensitive to variables such as the price of diesel fuel, pipe head loss, and the growth of the village load. The optimized system demonstrated a hydro energy potential of 1405.37 MWh/year and a PV energy output of 274.04 MWh/year, resulting in a levelized cost of energy of 0.0057 and 0.049 $/kWh for the hydro and PV components, respectively.

Applications and functions of wet fountain fittings used in pre-salt cluster of santos basin

"Fountain fitting " - deep and ultra- deep in the waters oil and natural dig it up removal for needed which is main underwater of equipment is one Petrobras well in Brazil the mouth with (Wet Christmas Tree – fountain armature ) between WCT installed (Production Adapter Base - production adapter base ) (PAB) . This equipment is a wellhead equipment used to install oil and gas wellhead, control it and control the mode of operation. There are Fontan fittings for surface (for wells drilled on land) and subsea (offshore wells). According to its construction, it is horizontal and has three steps. Fountain accessories consist of tube and belt head, Christmas tree fountain. The belt head located at the bottom of the fountain shield is used to hang the protective belt, close the gap between the pipes, etc. It is for the Pipe head to hang and seal the pump compressor pipe lowered into the well attached to the belt head. The resource head directs the product from the well to the discharge line, enabling control and monitoring of the well. The fountain armature is equipped with a pressure gauge and thermometer. BOP and fountain of the armature absolutely different equipment that it is clarify need a lot people this two underwater equipment mix it up because it can each two of them the well in the mouth is installed . Dump Blow-Out Preventer (BOP) of wells digging , completion and processing during use which is security equipment . His main components drawers (rams), annular discharge against preventers and suffocation and don't kill are lines (choke & kill lines). Fountain pipes are lowered into the well where the fountain is expected to shoot. It is necessary to hang these pipes from something at the wellhead and direct the product of the well to the outside through it, and for this, it is necessary to mold the space between the fountain pipes and the production line. In order for the fountain to pump in an optimal mode, to regulate the use of reservoir energy, it is necessary to create counter pressure at the well mouth by any means. Therefore, the equipment at the mouth of the fountain well must be able to create any back pressure in the discharge line, including closing the well. In addition, the wellhead equipment should allow to measure the pressures behind the pipe, in the discharge line, and also to inject gas or liquid into the well if necessary.

Numerical Simulation Analysis of Wellbore Integrity and Casing Damage in High-Temperature Injection and Production of Shale Oil

Shale oil represents a relatively new form of unconventional oil and gas resource, and the extensive exploration and development of shale oil resources carry significant implications for China’s oil and gas supply and demand dynamics. At present, within the realm of low-maturity shale oil extraction technologies, the reservoir must be subjected to elevated temperatures ranging between 400 to 60 °C. Prolonged exposure of wellbores to such high temperatures can result in a substantial decrease in cement strength, the formation of microcracks due to cement cracking, and damage stemming from thermal stresses on the casing. Casing damage stands out as a prominent factor contributing to wellbore integrity failures and well shutdowns within the context of shale oil development. Given the limited natural energy reservoirs of shale oil formations, it becomes necessary to supplement the reservoir’s energy during the development process. Furthermore, shale oil exhibits high viscosity and poor flowability, and conventional water injection methods yield limited efficacy. This situation can induce significant shifts in the stress field and rock mechanical parameters, potentially activating specific formations and complicating the load dynamics on the casing. Consequently, the risk of failure increases. In light of these considerations, this study uses numerical simulations to study the integrity of high-temperature injection and production wellbores in shale oil and aims to encompass a comprehensive evaluation and analysis of the principal factors that influence casing damage, the fluctuations in thermal stress, and the yield strength of various steel grades of casings exposed to alternating stress conditions. Subsequently, this paper developed a model for simulating the temperature and pressure within shale oil and steam injection wellbores to support engineering design analysis. The research results indicate that the application of pre-stress results in a significant increase in stress at the casing pipe head while causing a noticeable decrease in stress within the pipe wall. When N80 casing is used, the entire casing experiences thermal stresses surpassing the casing’s yield limit. Stress concentration may arise at both ends of the external seal, potentially leading to casing contraction, shear failure, and, under non-uniform stress conditions, casing bending deformation. The temperature of steam injection significantly influences the temperature field of the casing wall, with stress values experiencing a marked reduction when the steam injection temperature decreases from 350 °C to 200 °C, underscoring the substantial impact of temperature on casing thermal stress. As the steam injection process advances along with injection-production cycles, shear stresses at the interface can exceed the bond strength, resulting in relative slippage between the cement and the casing. The bonding force between the wellbore and the cement primarily depends on the interface’s friction, particularly in the context of friction during wellhead lifting. This study endeavors to determine rational injection and production parameters under varying conditions, optimize completion methods, reduce casing damage, and extend the casing’s operational life; it aims to offer critical technical support for the safe and efficient development of shale oil resources.

PROCESSING OF WELLHEAD CHRISTMAS TREES PIPE HEADER

In this study, the components of the tubing head of the Wellhead Christmas tree are classified. Information on how to install the tubing head to the Christmas tree (oil and gas) is also provided. The tested tubing head ensures the passage of liquid or gas into the spaces between the tubes. They have to control the pressure and conduct the necessary well studies. The tubing header seals and hangs the riser columns, which is especially effective when inserting concentric or parallel columns into the well. As a result of the conducted studies, the tubing head fully controls the flow of the technological liquid. Tubing headers to perform these processes should be manufactured according to the working pressure requirements between 14 and 105 MPa. Using a tubing head, you can connect different numbers of pipelines, as well as control the distribution of the medium flow in the circular zone of the valve. Of the cost-effective methods we have mentioned one is connected to the upper flange of the pipeline column header with a lower mounting fixing component. The design of the tubing head is completed by threaded holes in the body through which you can quickly replace the side valves in the head tube. The tubing head is designed to stop one or more rows of riser (pump and compressor) tubes and is used to perform technological operations during the development, operation and repair of wells. The top of the tubing at the wellhead is screwed into the tubing cap of the Christmas tree (oil and gas). Once installed at the wellhead, the Christmas tree (oil and gas) tubing header is compressed to the allowable pressure for pressure testing the production casing. Tubing head design and strength characteristics are shown in this figure: a) working pressure (7, 14.21, 35, 70 and 105 MPa), b) numbers of pipes lowered into the well (one and two concentric rows of pipes), c) constructions of locking devices (valves and taps) dimensions of the flow section along the trunk (50... 150 mm) and side branches (50... 100 mm). The tubing head holds and takes over the pressure generated between the tubes and can be prohibitive, which is quite dangerous for people's lives and health. Keywords: Christmas tree (oil and gas), tubing header, pressure, flow, wellhead, test, well.

Numerical investigation on the thermal performance of energy tunnels under groundwater flow and tunnel airflow

The integration of underground tunnels with ground heat exchangers (GHEs), also known as energy tunnels, is a promising technology that has gained attention in energy geotechnics research. This study investigates the coupled effects of groundwater and tunnel-air flows on the energy tunnel system via 3D thermo-hydraulic numerical modelling. It is found that the combination of groundwater flow parallel to the tunnel and limited airflow velocity results in reduced operational efficiency of ground source heat pump (GSHP) due to the strong thermal interference along the tunnel. The study also highlights the importance of real-scale modelling to evaluate the thermal yield of long energy tunnels, particularly when dealing with parallel groundwater flow in geothermal tunnel design.
 The use of shallow geothermal energy is a renewable solution towards net-zero carbon emissions. In recent years, a variety of conventional geotechnical structures, such as piles, retaining walls and tunnels, have been transformed into energy geostructures to also serve as GHEs to harness renewable energy for space heating and cooling purposes [7]. The thermal performance of energy tunnels is significantly affected by the presence of groundwater flow [1, 6] and the airflow in the tunnel [2, 4]. The groundwater flow and tunnel airflow can both be present in the field, however, their coupled effects on the energy tunnel system are hardly explored in the literature. This study aims to bridge this gap via real-scale numerical investigations.
 This study uses 3D thermo-hydraulic numerical modelling developed with the finite element package COMSOL Multiphysics [3]. The numerical model was successfully validated against an energy tunnel model-scale laboratory experiment [5]. Figure 1 shows the overall geometry and boundary conditions of the numerical model. A 48 m long tunnel section is thermally activated with the embedment of HDPE pipes (outer diameter of 25 mm and 2.3 mm thickness) placed in the lining segments at a spacing of 200 mm. A single tunnel ring consists of six segments with absorber pipes joined between them. Every four adjacent rings are connected in series to form a complete loop (with a single inlet and outlet), which is then connected in parallel to a flow and return header pipe(s). The entire thermally activated section comprises six loops, with identical fluid inlet temperature and flow rates, as they are fed by the same flow header pipe. The outlet fluid from each loop is mixed along the return header pipe to the GSHP. A constant 36 kW cooling thermal load is applied, and the simulation is run for ten years to allow the system to reach a steady state condition considering the minimum groundwater flow and airflow. The thermal properties of the ground are prescribed as 2 W/(m·K) and 1100 J/(kg∙K) for thermal conductivity and specific heat capacity, respectively.
 Figure 2 shows the entering water temperature (EWT, header outlet) and the coefficient of performance (COP) of the GSHP after 10 years of operation for different groundwater flow velocities and directions for tunnel air velocities = 0.05 m/s and 2 m/s.
 Results show that an increase in and leads to a decrease in EWT and an increase in COP. However, the effect of groundwater direction and velocity is more significant when airflow is limited ( = 0.05 m/s). The parallel groundwater flow leads to a higher EWT and lower COP than when the flow is inclined and perpendicular to the longitudinal tunnel axis. Consequently, the thermal performance of the system under parallel flow with a higher can be even worse than the perpendicular and inclined flow with a lower . When = 0.05 m/s, the EWT of parallel flow increases by 15% to 20% compared to the perpendicular flow, resulting in a maximum decrease of 15% in the COP. The effect of groundwater flow is much less significant when airflow is fast ( = 2 m/s): for increases from 0.05 to 2 m/d, EWT and COP change by no more than 13% and 5%, respectively, and the impact of groundwater flow direction is minor.

Lessons learnt from a full-scale installation of energy walls

The possibility of equipping diaphragm walls as ground heat exchangers to meet the full or partial heating and cooling demand of overlying or adjacent buildings has been explored in recent years [1, 2, 3, 4]. In this extended abstract a specific installation of energy diaphragm walls is described and the lessons learnt during the implementation discussed.
 The construction site is located in the city of Torino, in the campus of the Politecnico di Torino, where a new underground car park is under construction. The structure consists of four underground floors to be used as a car park for the staff at the academic site. The area of the excavation corresponds to a rectangle 173 m long and 35 m wide. The excavation is supported by more than 170 diaphragm walls. The maximum depth reached by the bulkheads is 17,65 m, while the excavation reaches approximately 15 m below the current ground level and above the water table. The ground at the site is an alluvial deposit consisting of sand and gravel locally cemented to form layers of conglomerate [5]. The construction process involves excavation by means of clamshell buckets, filling by bentonite slurry, lowering of the steel cage in two sections and bottom up filling by concrete.
 To boost the sustainability of its campuses, the Politecnico decided to make effective use of energy geostructures and to equip all single diaphragm walls with heat exchangers. A series of PE-Xa (cross-linked polyethylene) pipes of reduced diameter (32 mm) was introduced to allow the circulation of a heat transfer fluid.
 Considering that the steel cage of the diaphragm walls is constituted of two elements, the pipes were binded to the lower section of the rebar cages while laying in the construction site, before being lowered into the excavation. Two U-shaped pipes are installed for each diaphragm wall so that a distance of 60 cm separates each pipe. The inner pipes will be connected to the inlet, while the external pipes will be connected to the outlet. Pipes were placed on site with spacers to ensure the adequate passage of the concrete aggregates and avoid problems due to contacts with the ground at the excavation contour (Figure 1(a)). A distance of about 10 cm is achieved thanks to the spacers. An extra length of pipes is fixed to the rebar cage for later use.
 The steel cage is lifted by the crane and then lowered into the excavation. Once in place, it is hung to be connected with the upper part of the cage. Then lowering starts again. In this case, the extra pipe, previously hung onto the lower steel cage are unrolled and connected to the upper part of the steel cage by hand by the workers. This process requires the lowering of the cage to be interrupted systematically to allow for the workers to quickly make fast connections (Figure 1(b)). Once the whole steel cage is within the ground, the pipes are placed at rest with a protective coating. All pipes will be connected to inlet and outlet header pipes running outside the car park excavating area and directed to the central thermal power plant of the campus.
 The pipes’ condition was tested several times during the installation. First, a visual check, a pressurization and an emptying were performed before connecting the pipes to the lower part of the steel cage. Then, the pipes were filled with water before concrete casting and kept under pressure at 4 bar for 12 hours minimun during curing. The installation was considered successful if the pressure didn’t reduce by more than 0.1 bar. Despite the design considered the risk of losing up to 10% of the pipes due to unpredictable failures (e.g. crush, failures, contact, etc.), the final result, due to the careful workmanship, was that none of them had to be abandoned.
 The excavation of the area started in 2022, while completion and commissioning of the underground car park are expected for 2024. Connection of the heat exchangers to the heating system will take place after completion resulting in the largest application of energy walls in Italy.

Studi Tinjauan Perencanaan Sistem Plumbing Air Bersih (Studi Kasus: Gedung Sekolah Tinggi Ilmu Bahasa Arab)

carefully considered to ensure that the water demand of the students and staff can be met effectively and efficiently. Calculations show that a water demand of 0.35 m3/min is required, and various existing pipe diameters are used, ranging from 65mm for the main pipes, 60mm and 50mm for the header pipes, to 40mm, 32mm, 30mm, 25mm, 20mm, and 15mm for the shaft pipes. However, after controlling for velocity values using Epanet software, it was found that some pipes had values below 1.8m/s and above 2.4m/s, which could compromise system efficiency. Therefore, the effective pipe diameter for the header pipes was found to be 125mm and 90mm, and for the shaft pipes, it ranged from 90mm to 15mm. The results of this study highlight that the clean water piping system in the STIBA building must be carefully designed and evaluated to meet the clean water demands of the students and staff effectively and efficiently. This can be achieved by selecting effective pipe diameters based on the Epanet calculations and ensuring that the velocity values remain within the specified limits.

A Desing of Fuel Injection Pipe Head Forming Machine

A Desing of Fuel Injection Pipe Head Forming Machine

Neutral Per- and Polyfluoroalkyl Substances in In Situ Landfill Gas by Thermal Desorption–Gas Chromatography–Mass Spectrometry

Landfills receive over half of the municipal solid waste generated in the U.S. Wastes in landfills include consumer products, some of which are known to contain of per- and polyfluoroalkyl substances (PFAS). Although the occurrence of nonvolatile (ionic) PFAS in landfill leachate is established and volatile (neutral) PFAS are found in ambient air near landfills, the neutral PFAS composition of landfill gas (LFG) collected in situ from landfills is unknown. A thermal desorption–gas chromatography–mass spectrometry (TD-GC-MS) sampling and analysis approach was optimized for the quantification of 25 target neutral PFAS, including fluorotelomer alcohols (FTOHs) and five other PFAS classes, in landfill from a gas well or header pipe. Optimized LFG sampling parameters included the use of an explosion-proof pump, a 100 mL/min flow rate through a sorbent tube, and a LFG volume of 350 mL. The method was applied to LFG samples collected from southeastern U.S. landfills for method demonstration. Fluorotelomer alcohols were found at the highest levels, ranging from 830,000–4,900,000 pg/m3, which is approximately 2 orders of magnitude greater than FTOH levels reported in ambient air collected near landfills.

Uncertainty measurement and research of Finite element analysis of Water Jet data based on Internet of Things

Nowadays, the concept of energy saving and water saving is deeply rooted in people’s minds, so it is necessary to promote efficient water-saving irrigation technology. Sprinkler irrigation is an efficient water-saving method, which is relatively uniform and does not affect the structure of the soil. It saves time and labor to irrigate fields, and has been used in more and more areas in China. The Internet of things technology is used to establish monitoring sites, collect and transmit water information, study and analyze crop fertilization and irrigation water volume, and achieve the purpose of saving water, fertilizer and labor. In test site traffic and sprinkler relationship between speed and pressure test, flow and in different pressure conditions were measured under different conditions of running speed, observe the fluid flows through the three links of pipe head loss and energy loss of the tee to the role of the internal pressure and axial force and other force, high stress concentration areas vulnerable to damage. The hydraulic characteristics in the process of water spraying are studied. The numerical simulation in this paper is completed by finite element software, and the hydraulic characteristics of the three-way pipe are analyzed by finite element to optimize the structure of the three-way pipe.

Research on Autopsy Results of over 10 Year Old Low Pressure Hollow Fiber Membrane from Domestic Water Treatment Plant

Objectives : In this study, membrane autopsy was performed for a parallel arrayed low-pressure membrane (microfiltration) filtration process that is actually applied to water treatment, to check out whether there are differences in the degree of membrane fouling due to the uneven flow rate into each module. Also, membrane foulants were evaluated quantitatively.Methods : In this study, autopsy was performed for over 10 year old membranes used for drinking water purification. In this way, the outer casings of membrane modules at different positions were disassembled and visually observed. In addition, In addition, the size of the pores and the porosity were investigated by taking a SEM (Scanning Electron Microscope) photograph for the new and the used membrane module fiber samples in different positions from the header pipe. The used membrane foulants were classified into organic and inorganic matters and quantitatively analyzed.Results and Discussion : As a result of visually observing inside the membrane module that has produced drinking water for over 10 years, the inside of the No. 1 membrane module close to the inlet was contaminated with black foulants. On the other hand, in the case of No. 10 membrane module located farthest from the header pipe inlet, no foulants were observed with the naked eye. Also, it was observed from SEM photograph results that there were large differences in the surfaces among No. 1, 4, 6, 8 and 10 MF module fibers.Conclusion : Even after periodic physical and chemical cleaning, it was concluded that the fouling levels were different each other in the parallel arrayed low-pressure membrane modules. In addition, the pore size distribution and porosities of the membrane modules may vary depending on the position.

Application of Double Piping Theory to Parallel-Arrayed Low-Pressure Membrane Module Header Pipe and Experimental Verification of Flow Distribution Evenness.

In this study, the improvement effect of flow distribution evenness is evaluated quantitatively by applying the double piping theory to a parallel-arrayed low-pressure membrane module header pipe structure, and its feasibility is discussed. Orifice inner pipes to be inserted into a full-scale membrane module header pipe are designed via the computational fluid dynamics (CFD) technique, and the flow rates into 10 membrane modules are measured in real time using a portable ultrasonic flowmeter during operation to verify the effect. Results of CFD simulation and actual measurements show that the outflow rate from the branch pipe located at the end of the existing header pipe is three times higher than the flow rate from the branch pipe near the inlet. By inserting two inner pipes (with an open end and a closed end into the existing header pipe) and applying the double pipe theory, the flow distribution evenness is improved. The CFD simulation and experimental results show that the flow uniformity can be improved by more than 70% and 50%, respectively.

The Features of Heat and Mass Transfer in the Operation of Nuclear-Powered Icebreaker Steam Generators

The problem of hydrogen induced embrittlement of and crack formation in the piping systems of nuclear-powered icebreaker steam generators is considered. Information about the relevance of this problem for ensuring reliable operation of the nuclear power installations of transport facilities and similar systems such as floating nuclear power units is given. Hydrogen accumulation in the steam generator feedwater header pipes welding zone and their subsequent hydrogen-induces embrittlement lead to crack formation. For modeling the hydrogen transport processes from the reactor to the steam generator, two types of computer codes are jointly used: 1D approximation and 3D ones. The performed analysis has identified the main characteristic processes. For solving the problem, it was decomposed into subproblems. The transport of vapor-gas bubbles in the steam generator was analyzed with paying special attention to studying their behavior in the steam generator internal cylinder. It is shown that, despite the presence of structural obstacles in the inner cylinder, coolant convective motion and bubble floatation occur. An alternative hypothesis is put forward, according to which cracks may be caused by cavitation on the secondary system coolant side. To check the hypothesis, 3D modeling was carried out, the results of which did not confirm its validity. The obtained study results can be used to substantiate measures on preventing the hydrogen-induced embrittlement of and crack formation in the steam generator piping systems of nuclear-powered icebreakers, floating nuclear power units, and small capacity NPPs.

Investigation on mechanical and tribological properties of AA6061/Gr composites for solar header pipes

Solar header pipes desire light weight material with extensive mechanical and tribological property at high temperature. In this research work, an attempt was made to reinforce AA6061 aluminium alloy with Graphite particles through Stir Casting (SC) and Compo Casting (CC) technique for solar header pipes. The uniform dispersion of reinforcing particles over the matrix was confirmed through Scanning Electron Microscope (SEM). The tensile, hardness and wear experiments were performed on composites at elevated temperature. The wear experimental runs were designed using Taguchi mixed orthogonal array by varying temperature, applied load, sliding velocity, sliding distance and reinforcing weight percentage. The composites produced through CC method exhibit 3.8% and 2.7% higher hardness and tensile strength in comparison with SC. At elevated temperature of 300 C, the composites exhibit better wear resistance owing to the formation of Mechanical Mixed Layer (MML). The wear rate of composites at elevated temperature was three times higher than the room temperature owing to reduction in density and deformation of material. ANOVA table reveals that the most influencing process parameters was temperature followed by the load and percentage reinforcement. The worn surface morphology was analyzed using SEM. Because of the improved dispersion of reinforced particles, the composites generated by CC have higher mechanical and tribological qualities at elevated temperatures, and are considered as an alternative material for solar header pipes.

User-friendly fault detection method for building chilled water flowmeters: Field data validation

In building HVAC systems, a chilled water flowmeter is an important sensor. Its reading can be used to measure the real-time cooling load, which is a critical variable for the automated control of building HVAC systems, especially central chiller plants. To maintain accurate reading data, fault detection and diagnosis (FDD) of flowmeters are necessary. The available FD/FDD methods for chilled water flowmeters have several common disadvantages: (1) high requirements on sensor integrity: multiple sensors are usually involved in the construction of energy balance models; (2) complex methodology: the fault of any monitored sensor could trigger a detection hit, and a diagnosis procedure must be used to isolate the faulty sensor; and (3) the more sensors that are involved, the more difficult it is to collect fault-free historical data for the establishment of a fault-free benchmark. To address these problems, a user-friendly fault detection (FD) method for building chilled water flowmeters is proposed in this study. The proposed method requires three types of variables to function: the pump frequency, the pump power, and the measured chilled water flow rate on the header pipe. The real-time pump frequency and electrical power data that are collected by VFDs/power meters are used to estimate the true value of the chilled water flow rate with random forest regressor. An auxiliary alarm rule is proposed to tackle the tradeoff issue between detector sensitivity and false alarm rate. Field data of a real HVAC system are used in a case study to evaluate the performance of the proposed method in comparison with three existing FD methods. The results of the validation case study suggest that compared to existing FD methods, which are based on the physical pump model, ensemble learning and clustering techniques, the proposed method could realize higher hit rates and higher alarm rates when confronting different faults (bias, noise and drift) at various levels. Besides, due to the proposed alarm rule, false alarms caused by occasional data errors are completely evaded. Sensitivity analysis to the proposed method indicates that the random forest with default hyperparameters is good enough for the FD task. In brief, the good features of the proposed method (i.e., the simple workflow, low sensor requirements, accessible robust input variable data, handy estimation model, auxiliary alarm rule with tight detection threshold) render the proposed method feasible and user-friendly for engineering practice.

PERANCANGAN PEMBANGKIT MIKROHIDRO PADA SALURAN PDAM MATA AIR LEWAJA KABUPATEN ENREKANG SULAWESI SELATAN

Electrical energy has become a part of our life. In fact, for some people it has become a major need that cannot be eliminated. This can affect the energy sources used in the power generation process. Therefore, the existence of renewable energy sources is needed to increase the energy supply for the community. In this case the author tries to do research to take advantage of the water discharge at the Lewaja Spring PDAM, Enrekang Regency, South Sulawesi as a Micro Hydro Power Plant (PLTMH). apipa, so that production costs can be reduced. In addition, it can provide an overview to the PDAM and the community that the PDAM pipes, which so far have only been used for water distribution, can be used as power plants. The purpose of this research is to determine the discharge and pipe head of PDAM and then the dimensional design of the turbine is based on the potential obtained. The survey was conducted to obtain primary data and secondary data. the main data is data obtained directly, while secondary data is data obtained from documents stored in PDAM Lewaja Springs. From the research, the average discharge is 46,287 L/s under normal conditions, and has a water level of 5,998 m from the turbine location

A Study on the Evaluation of Flow Distribution Evenness in Parallel-Arrayed-Type Low-Pressure Membrane Module Piping.

The objectives of this study were to measure the flow rate distribution from a header pipe to each module installed in parallel for a water treatment membrane filtration process in operation and to investigate the reason for an uneven distribution of the flow rate via the CFD technique. In addition, this study attempted to propose the ratio of the branch pipe to the header pipe required to equalize the flow distribution for the same membrane filtration process. Finally, the relationship between the Reynolds number in the header pipe and the degree of the manifold flow distribution evenness was investigated. Mobile ultrasonic flow meter was used to measure the flow rate flowing from the membrane module pipe to each module, and the CFD technique was used to verify this. From the results of the actual measurement using ultrasonic flow meter and CFD simulation, it was confirmed that the outflow flow rate from the branch pipe located at the end of the header pipe was three times higher than that of the branch pipe near the inlet. The reason was that the differential pressure generated between each membrane module was higher toward the end of the header pipe. When the ratio of the sum of the cross-sectional area of the branch pipe and the cross-sectional area of the header pipe was reduced by about 30 times, it was confirmed that the flow rate flowing from each branch pipe to the membrane module was almost equal. Also, if the flow in the header pipe is transitional or laminar (Reynolds No. is approximately 4000 or less), the flow rate flowing from each branch pipe to the membrane module can be more even.