Investigation on the Effect of Impeller Design Parameters on Performance of a Low Specific Speed Centrifugal Pump Using Taguchi Optimization Method

In order to investigate the effect of blade design on pump performance, a CFD analysis was carried out, and the results were compared with experimental performance data of a low specific speed radial pump, which presents a good agreement. After model verification, the effect of impeller geometrical parameters includes blade outlet angle, wrap angle, and width at the exit, was investigated on the pump’s performance. Moreover, these parameters were chosen on three levels using an L9 orthogonal standard array of the Taguchi optimization method. The efficient levels of variables were calculated using the analysis of variance (ANOVA) method. The results revealed that impeller width at exit and blade outlet angle is the most effective pump shaft power and efficiency parameters. To minimize power, the optimal levels are the outlet angle of 27∘∘, wrap angle of 150∘∘, and width at the exit of 9 mm. Further, an outlet angle of 23∘∘, a wrap angle of 155∘∘, and a width at the exit of 9 mm lead to maximum pump efficiency. According to the validation simulations, an increase of 2.4% inefficiency and a minimum power of 3.9KW were achieved. The Overall Evaluation Criteria (OEC) technique revealed that considering 23∘∘, 160∘∘, and 9 mm for outlet angle, wrap angle, and width at the exit, minimum shaft power, and maximum pump efficiency will be achieved. ANOVA introduced width at the exit as the most governing parameter of pump performance characteristics.

Submarine Groundwater and River Discharges Affect Carbon Cycle in a Highly Urbanized and River-Dominated Coastal Area

Riverine carbon flux to the ocean has been considered in estimating coastal carbon budgets, but submarine groundwater discharge (SGD) has long been ignored. In this paper, the effects of both SGD and river discharges on the carbon cycle were investigated in the Guangdong-HongKong-Macao Greater Bay Area (GBA), a highly urbanized and river-dominated coastal area in China. SGD-derived nitrate (NO3–), dissolved organic carbon (DOC), and dissolved inorganic carbon (DIC) fluxes were estimated using a radium model to be (0.73–16.4) × 108 g/d, (0.60–9.94) × 109 g/d, and (0.77–3.29) × 1010 g/d, respectively. SGD-derived DOC and DIC fluxes are ∼2 times as great as riverine inputs, but SGD-derived NO3– flux is one-fourth of the riverine input. The additional nitrate and carbon inputs can stimulate new primary production, enhance biological pump efficiency, and affect the balance of the carbonate system in marine water. We found that SGD in the studied system is a potential net source of atmospheric CO2 with a flux of 1.46 × 109 g C/d, and river, however, is a potential net sink of atmospheric CO2 with a flux of 3.75 × 109 g C/d during the dry winter season. Two conceptual models were proposed illustrating the major potential processes of the carbon cycle induced by SGD and river discharges. These findings from this study suggested that SGD, as important as rivers, plays a significant role in the carbon cycle and should be considered in carbon budget estimations at regional and global scales future.

Optimization Design of Energy-Saving Mixed Flow Pump Based on MIGA-RBF Algorithm

Mixed flow pumps driven by hydraulic motors have been widely used in drainage in recent years, especially in emergency pump trucks. Limited by the power of the truck engine, its operating efficiency is one of the key factors affecting the rescue task. In this study, an automated optimization platform was developed to improve the operating efficiency of the mixed flow pump. A three-dimensional hydraulic design, meshing, and computational fluid dynamics (CFD) were executed repeatedly by the main program. The objective function is to maximize hydraulic efficiency under design conditions. Both meridional shape and blade profiles of the impeller and diffuser were optimized at the same time. Based on the CFD results obtained by Optimal Latin Hypercube (OLH) sampling, surrogate models of the head and hydraulic efficiency were built using the Radial Basis Function (RBF) neural network. Finally, the optimal solution was obtained by the Multi- Island Genetic Algorithm (MIGA). The local energy loss was further compared with the baseline scheme using the entropy generation method. Through the regression analysis, it was found that the blade angles have the most significant influence on pump efficiency. The CFD results show that the hydraulic efficiency under design conditions increased by 5.1%. After optimization, the incidence loss and flow separation inside the pump are obviously improved. Additionally, the overall turbulent eddy dissipation and entropy generation were significantly reduced. The experimental results validate that the maximum pump efficiency increased by 4.3%. The optimization platform proposed in this study will facilitate the development of intelligent optimization of pumps.

Quadrant Mapping Artificial Lift Concept

This paper outlines a concept for monitoring performance of artificial lift performance such as electrical submersible pump (ESP), hydraulic pumping unit (HPU), sucker rod pump (SRP) and progressive cavity pump (PCP), for a large number of wells. The objective is to generate simplified monitoring performance of artificial lift with a huge number of wells on one page by creating quadrant mapping consisting of two coordinates with x axis representing pump efficiency and y axis showing pump submergence. We made a four-quadrant limit by pump efficiency (50%) and submergence (200 m). Optimum wells will show on range pump efficiency above 50% and submergence below 200 m, and 3 other quadrants are classified as artificial lift problems, well potential and sizing/design problems. By using the quadrant mapping concept, we can generate performance of artificial lift for 1500++ wells in one page, and this mapping consists of four quadrants (quadrant 1, quadrant 2, quadrant 3 and quadrant 4), quadrant 1 (Submergence above 200 meter and lifting efficiency below 50%) showing wells which have artificial lift problem, quadrant 2 (Submergence is above 200 meters and efficiency is above 50%) showing well which have potential to increased production, quadrant 3 (Submergence is below 200 meters and efficiency is above 50%) showing the optimum wells operation and quadrant 4 (Submergence is below 200 meters and efficiency is below 50%) showing the wells which required to re-sizing/re-design artificial lift. This quadrant mapping can be shown to Engineers, manager's and shareholder to show overall performance and classification detailed problems to create a troubleshooting, optimization program to increased oil production, run life artificial and result in better production performance. This mapping also helps petroleum engineers to get a better field view and create priorities and program optimization based on the quadrant mapping result and classification.

Energy Efficiency Indicators for Water Pumping Systems in Multifamily Buildings

With the current concerns about sustainable development and energy consumption in buildings, water pumping systems have become essential for reducing energy consumption. This research aims to develop guidelines for the energy assessment of water pumping systems in multifamily buildings. The methodological procedures are: (i) definition of the efficiencies of electric motors; (ii) definition of pump efficiency levels; (iii) determination of energy consumption; and (iv) construction of the efficiency scale and guidelines for projects and assessments. The results obtained were that centrifugal pumps with 40% efficiency have higher energy consumption, regardless of the efficiency class of the electric motors, showing a 20% increase in electrical energy consumption. Lower efficiencies directly impact the energy efficiency rating of the water pumping system. Thus the 40% efficiency obtained energy efficiency rating “Very Low—VL” for all motor efficiency classes (between IE1 and IE5). At 60% efficiency, the energy efficiency level of the system was “Average—A”, gradually increasing to “Very High—VH”, as the energy consumption in the pumps decreased and the motors’ energy efficiency classes increased. It is concluded that designers and professionals in the area must consider the efficiency of the pumps, as they play a fundamental role in the classification of the system’s energy efficiency. It is also recommended to verify the energy efficiency of the water pumping system and implement design guidelines so that the pumping system achieves lower energy consumption, contributing to the building’s energy efficiency and sustainability.

Feasibility of Utilizing Photovoltaics for Irrigation Purposes in Moamba, Mozambique

Agriculture plays a significant role in the labor force and GDP of Mozambique. Nonetheless, the energy source massively used for water pumping in irrigation purposes is based on fossil fuels (diesel oil). Despite the water availability and fertile soils in Moamba, Mozambique, farmers struggle with the high cost of fuels used in the pumping systems. This study was sought to analyze the feasibility of utilizing a solar photovoltaic system as a means to reduce the environmental impact caused by the diesel pumps and simultaneously alleviate the expenses regarding the use of non-environmentally friendly technologies. Site observations and interviews were undertaken in order to obtain local data regarding the water demand, current energy systems costs and distances from the source to the irrigated fields. CLIMWAT 2.0 was used for climate data acquisition and analysis. The environmental benefits, the cost effectiveness and local climate conditions show that the PV system is feasible in Moamba. Furthermore, parameters such as hydraulic energy, incident solar energy, pump efficiency and total system efficiency were used to predict the performance of the system. The results obtained are important to analyze the implementation of such energy systems.

Unlocking ESP Potential in High Gas/Liquid Ratio Wells Using Gas Lock Prevention Control in West Java Field, Indonesia

West Java field operated 60 electric submersible pumps (ESPs) as a lifting method with 2.850 BOPD production contribution. These ESP wells produce from a mature structure. At one point, 48% of ESP operation were shut down due to ESP non-optimum operation. The challenges in ESP operations in the asset are high gas-liquid ratio (GLR), impurities, sand and scale buildup, and well integrity where high GLR was deemed as the major problem that deteriorated the ESP's performance. Conventional ESPs gas separator were installed in the field, but the gas-handling device could not handle more than 45% free gas while some wells have more than 50% free gas. Three wells in particular were assessed, Well A, Well B, and Well C, which have 585, 1196, and 1690 average GLR respectively. These wells had problem with reduced pump efficiency and very low run life due to frequent ESP trips which were caused by the gas lock problem. A solution to maintaining oil production was by changing the production zone to zone that producing less gas and by installing more advanced gas-handling device. However, the probability of experiencing high gas production from new zones can't be ruled out therefore other mitigation plan had to be found. Gas lock protection control is an algorithm that manipulates ESP real-time rotational speed to prevent gas interference inside pump. The algorithm was introduced as a mitigation measure and commissioned in July 2020 at Well A where it directly optimized production by 16%. To prove the robustness of the gas lock prevention control, the project was then extended to Well B and Well C which began to implement gas lock prevention control in August 2020 to handle the increase of their gas production. Thanks to this gas lock prevention control, the wells have been able to maintain production without spending either time or money to change production zone or to change the ESP completion. Going forward, gas lock protection control will be set as an option on ESP devices. Thus, unplanned gas interference effects may be reduced in other wells that being produced by ESP thereby helping to maintain production at an optimum level.

Development and Evaluation of a New Electrical Submersible Pump for High Viscosity Environments

Conventional methods of Heavy Oil production have either delivered low recovery factors or have involved costly thermal projects. With low oil prices the new norm, Operators need to maximize their recovery factors whilst controlling CAPEX required to exploit their assets. This paper presents a new approach to lifting heavy/viscous oil with a Pump design that will allow Operators to increase overall field production with reduced energy consumption. A trial was conducted in Colombia in a harsh field (high viscosity, low water cut, high temperature and high gas production) that had challenged conventional artificial lift systems as Electrical submersible pumps and progressive cavity pumps. Several strategies (light oil injection, high capacity equipment, solvents injection at surface) had been implemented to overcome fluid viscosities 6,000 cP @ 150 °F at dead oil conditions and a mean of 250 cp inside the pump, with excellent short and medium-term results but system hydraulic efficiency and energy consumption were still below expectations. A new pump has been specially designed for the fluid conditions previously described, with the main objective of reduce the friction losses inside the pump stage increasing the overall efficiency and reducing energy consumption. Initial trial results have fulfilled the study's objectives, overcoming the issues previously experienced with ESP operations in this field. Designed to handle heavy, high viscosity oil, this study has demonstrated that there is significant economic benefit through savings and improved efficiencies and, in addition, ESP capital cost savings. Previously, oversized units were routinely used to deliver the required flow and pump power but by optimizing the sizing of the ESP system, it is possible to select pumps with fewer stages and lower horsepower motors to suit the new requirements. Data from the field tests have delivered encouraging results. The pump has operated smoothly since installation and, in comparison to standard pump, has reduced energy consumption (savings of 10-15%) and shown a 15-20% increase in pump efficiency. The Operator has reasonable optimistic expectations for future installations in this field in all applicable wells.