Liquid Pump Research Articles

A Review on Biomimetic Cilia Microrobots: Driving Methods, Application and Research Prospects

Abstract: With the development of science and technology, microrobots have been used in medicine, biology, rescue, and many other fields. However, the microrobots have problems such as energy and motion due to miniaturization. In order to solve the problem of the energy supply of microrobots, researchers have provided more drive schemes for microrobots. Inspired by the biological cilia, the biomimetic cilia have been developed and applied to microrobots to achieve propulsion, liquid pumping, liquid mixing, and particle manipulation. This review summarizes the different driving modes of microrobots, focusing on the application of magnetic drive and optical drive in the field of micro-robots. The structure and function of biological cilia and biomimetic cilia are introduced. The application of biomimetic cilia microrobots in various fields is discussed, and the current challenges and future development trends of biomimetic cilia microrobots are summarized. This review hopes to provide useful help for researchers of biomimetic cilia microrobots

Research on energy loss mechanism and optimization method of liquid ring vacuum pump based on entropy production theory

Research on energy loss mechanism and optimization method of liquid ring vacuum pump based on entropy production theory

Experimental comparison of cycle modifications and ejector control methods using variable geometry and CO2 pump in a multi-evaporator transcritical CO2 refrigeration system

To reduce the direct global warming impact of refrigerants in HVAC&R applications, low-global warming potential (GWP) refrigerants, including natural refrigerants, have been extensively investigated as alternatives to hydrofluorocarbon (HFC) refrigerants. Among the natural refrigerants, Carbon Dioxide (CO2) offers several advantages, such as excellent transport and thermo-physical properties, being neither toxic nor flammable, and having a low price and high availability around the world. However, the high critical pressure and low critical temperature of CO2 often lead to transcritical operation, resulting in lower efficiency due to the additional compressor power necessary to achieve transcritical operation relative to subcritical HFC cycles. Therefore, a number of cycle modifications are used to enhance the coefficient of performance (COP) of transcritical CO2 cycles to meet or surpass those of HFC cycles. This paper provides a systematic experimental investigation of four such cycle architectures by employing the same multi-stage, two-evaporator CO2 refrigeration cycle test stand, 3 of these configurations in transcritical and 1 in subcritical conditions. The four cycles architectures included intercooling, open economization, an internal heat exchanger and two different ejector control approaches. Specifically, a variable-diameter motive nozzle and a variable-speed liquid CO2 pump located directly upstream of the ejector motive nozzle inlet were analyzed. Based on the experimental data, the maximum COP improvements are 4.64 % and 9.47 % when the ejector and the internal heat exchanger are used, respectively. The CO2 pump, once successfully stabilized, can control the ejector, increase its efficiency by up to 15 % and increase the cooling capacity to a maximum of 6.2 %. Nevertheless, a reduction in COP is measured when the pump is in use; however, unlike the other three different configurations, it was only analyzed under subcritical conditions.

Application of drag reduction agents as a method for reducing heat loss during pumping through a pipeline

Relevance. The need to maintain the temperature regime of product pumping under increasingly complex conditions of pipeline routes by reducing heat losses of oil and petroleum product pipelines, as well as expanding the scope of application of anti-turbulence additives. Aim. To determine the effect of anti-turbulence additives on heat and hydraulic losses in the pipeline and to propose cost-effective ways to use additives when pumping through pipelines. Objects. Heat and hydraulic losses in pipelines pumping oil and oil products. Methods. Mathematical analysis of the influence of anti-turbulence additives on the thermohydraulic properties of the flow to assess the prospects for increasing the energy efficiency of pumping liquid through pipelines by introducing polymer additives. Results. The flow temperature was calculated using anti-turbulence additive depending on its concentration and efficiency, taking into account the dependence of the properties of the pumped product on temperature. The authors have constructed the graphic dependences of the economic components of heat and hydraulic losses on the concentration of anti-turbulence additives. The economic feasibility of the decision was estimated in terms of calculating the difference in pumping costs with and without anti-turbulence additives. The authors identified the relationship between the impact of losses from friction heat and heat exchange with the environment on heat losses, and analyzed the change in these parameters after the introduction of anti-turbulence additives. For the pipeline under consideration, the parameters of which correspond to standard pumping ones, the сonclusions were drawn on the predominance of the contribution of the additive hydraulic efficiency over the thermal one. This indicates the advisability of using an anti-turbulence additive as an agent for reducing heat losses at high values of the efficiency of the polymer additive, however, the overall economic efficiency is maximum at lower concentrations of the agent. The authors constructed a planar graph reflecting the dependence of the temperature at the end of the pipeline section on two coordinates: the length of the section and the hydraulic efficiency of the introduced additive.

Optimization of vacuum membrane distillation and advanced design of compact solar water heaters with heat recovery

With the escalating global population, freshwater scarcity has become a pressing challenge. To address this issue, this paper presents a novel compact solar water heater (CSWHT) system incorporating heat recovery and submerged-membrane filtration. The research aims to develop an efficient desalination method that reduces water production costs and maximizes output. The system comprises a feed storage tank, a vacuum membrane distillation (VMD) system positioned atop the submerged CSWHT, a liquid ring vacuum pump (LRVP) utilizing waste heat from the outlet to preheat the feed, and hollow fiber membranes.Three critical parameters, namely the mass of the feed in the storage tank, the number of hollow fiber membrane rows, and the feed volumetric flow rate, were optimized using a multi-objective non-dominated sorting genetic algorithm II (NSGA II) to minimize water production cost (WPC) while maximizing water production. Subsequently, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) was employed to identify the optimal scenario from among the selected best solutions.For Mediterranean seawater and a 6 m2 solar collector area, the multi-objective NSGA II algorithm identified 20 membrane rows per collector, 334.4 kg feed mass in the storage tank, and 0.027 kg.s−1 feed mass flow rate as the optimal system parameters. Under these optimized conditions, the system exhibited a daily production capacity of 92.5 kg water, 4.6 kg chloride, and 0.03 g bromide, while achieving a production cost of 12.2 USD.m−3 and a gain output ratio (GOR) of 1.6. These results highlight the system's remarkable potential for desalination with high efficiency and low cost. Future research should focus on scaling up the system and exploring its applicability in various geographical locations.

Benefits of In Situ Foamed and Printed Porous Scaffolds in Wound Healing.

Macroporous hydrogels have shown significant promise in biomedical applications, particularly regenerative medicine, due to their enhanced nutrient and waste permeability, improved cell permissibility, and minimal immunogenicity. However, traditional methods of generating porous hydrogels require secondary post-processing steps or harmful reagents making simultaneous fabrication with bioactive factors and cells impossible. Therefore, a handheld printer is engineered for facile and continuous generation and deposition of hydrogel foams directly within the skin defect to form defect-specific macroporous scaffolds. Within the handheld system, a temperature-controlled microfluidic homogenizer is coupled with miniaturized liquid and air pumps to mix sterile air with gelatin methacryloyl (GelMA) at the desired ratio. An integrated photocrosslinking unit is then utilized to crosslink the printed foam in situ to form scaffolds with controlled porosity. The system is optimized to form reliable and uniform GelMA foams. The resulting foam scaffolds demonstrate mechanical properties with excellent flexibility making them suitable for wound healing applications. The results of in vitro cell culture on the scaffolds demonstrate significantly increased cellular activity compared to the solid hydrogel. The in vivo printed foam scaffolds enhanced the rate and quality of wound healing in mice with full-thickness wound without the use of biological materials.

Synthesis and characterization of MWCNTs nanocomposite for fabrication of tensometric transducers

A nanocomposite was prepared using MWCNTs and micro-sized bronze particles dispersed in elastomer silicone organic compound (SILAGER 8030). The nano-composite was characterized by FT-IR, SEM, EDS and Raman spectroscopy; showing the rough surface of the composite with interweaving of nano threads. This nano-composite was used to manufacture strain gauge. The conductivities were measured concerning wt% of micro-sized bronze, compression and time. The maximum electrical conductivity obtained was 2.1 S/m at 5.0 wt% bronze metal alloy and MWCNT (3.0 wt%) at 16% compression. With increasing amplitude and frequency of ultrasonic exposure, an increase in the pressure associated with cavitation in the liquid was observed. Each value of ultrasound exposure corresponded to a certain value of electrical resistance. At the same time, with an increase in the intensity of the cavitation effect on the strain gauge transducer, extremum points appeared, which corresponded to a decrease in resistance. The developed material is highly useful for manufacturing strain gauges to be used in liquid ring vacuum pumps as a measuring transducer of liquid ring pressure into signals associated with changes in resistance. This allows liquid ring vacuum pumps to be precisely controlled; improving their energy efficiency and reliability.

A comprehensive study on active mixer performance using liquid metal droplets: an experimental approach

In this experimental study, we delve into the performance of an active mixer that utilizes liquid metal droplets. Our mixer configuration follows an innovative Y-type design, where two liquid metal-based pumping mechanisms operate within the minichannel inlet branches. By applying alternating current voltage to both sides of the liquid metal, we induce a surface tension gradient, propelling the fluid from the reservoirs toward the minichannel. Notably, the two entering liquids are distinctly colored, allowing us to quantify mixing using a Mixing Index (MI) definition and image processing techniques. Our investigation centers on four key variables governing mixer performance: applied voltage, liquid metal droplet diameter, input angle between the branches, and minichannel width. Given the experimental nature of our research, we employ a central composite design method within the framework of design of experiments (DoE). From our obtained experimental results, we establish correlations between MI and the other variables. Our examination of the four mentioned parameters revealed that liquid metal droplet diameter exerts the most significant influence on the mixing index. Following this, in descending order of impact, we find applied voltage, input angle, and channel width. In the optimal dimensions of our mixer, we achieve a remarkable maximum MI of 0.867.

Experimental study on a pump-driven CO2 two-phase thermosyphon loop

In order to better understanding the internal operating principles of liquid pump-driven two-phase thermosyphon loop (LPTPTL) and promote the application of environmentally friendly working fluids, a LPTPTL using CO2 as the working fluid was studied through experiment. Both the operating mechanisms and performance of the CO2 LPTPTL was investigated. It was found that the impact of the pump on the two-phase thermosyphon loop (TPTL) varies significantly across different operation stages. During the oscillatory operation stage, activating the liquid pump eliminated the geyser boiling in the loop and made the TPTL to transition from oscillatory to stable operation. During the normal operation stage, the pump power had little effect on the total thermal resistance of the TPTL. While the system’s EER (Energy Efficiency Ratio) significantly decreased with the increasing pump power. During the overload operation stage, activating the liquid pump helped alleviate overheating or subcooling in the loop. With the pump power increasing from 3.0 W to 18.8 W, the heat transfer limit of the TPTL increased from 1800 W to 3300 W, while the system’s EER decreased from 600 to 176. This study proves the feasibility of CO2 LPTPTL, and provides theoretical guidance for its real application.

曲柄摇杆式深施机构的设计与施肥性能试验研究

In response to the poor fertilization performance of the deep application mechanism of the deep application liquid fertilizer applicator under multiple parameters, the fertilization variation of the crank rocker deep application mechanism under multiple working parameters is explored. To obtain the fertilization variation of the crank rocker deep application mechanism, a fertilization performance test bench for the crank rocker deep application mechanism is developed. On this test bench, the crank speed, liquid pump pressure, and spray hole diameter are used as experimental factors, and fertilizer application rate is used as experimental indicators. A composite design scheme of rotation center is adopted to establish a relationship model and response surface diagram between experimental influencing factors and influencing indicators. Design Expert 8.0.10 software is used to analyze and optimize the experimental data. The optimal results are a crank speed of 145.80 r/min, a liquid pump pressure of 0.25 MPa, a spray hole diameter of 3.02 mm, a fertilizer application rate of 28.6 mL, and a fertilizer loss rate of 1.9%. At this time, the fertilization performance of the mechanism is optimal. This parameter combination is applied for testing and verification to verify its rationality. The results can ensure that the crank rocker deep application mechanism has good working performance when working under multiple parameters, providing theoretical reference for designing deep application liquid fertilizer machines with simple structure and optimal fertilization performance.

Design and research of fuzzy PID-based liquid pump performance testing platform

Abstract The pump is a crucial component of agricultural sprayer machinery, directly impacting its operational quality. This paper designs a performance testing platform for pumps. Utilizing a brushless DC motor as the power source for the pump, a closed-loop mathematical model for the brushless DC motor is established. Simulation experiments and indoor experimental tests are conducted. Simulation results indicate that the motor control system exhibits fast response, no overshooting, and excellent dynamic and static performance. Experimental tests on the platform show that the error range of motor speed is less than 0.3%, achieving excellent control performance. The constructed pump performance testing system achieves precise measurement of pump flow rates at different speeds, demonstrating outstanding performance.

Исследование процессов тепломассопереноса в нефтяной скважине с~призабойным нагревателем различной длины

This paper considers a three-dimensional mathematical model of heat and mass transfer in an oil well with a bottom-hole heater. The vertical section of an oil well with an electric bottom-hole heater device for wells with highly viscous and paraffinic oil was investigated. The bottomhole heater is a monolithic cylinder located in the lower part of the tubing. The tubing contains perforations through which the oil fluid enters the tubing. The use of a local heater in the near-wellbore area makes it possible to increase the temperature of the fluid flowing through it, thereby reducing the viscosity of the oil and the load on the electric centrifugal pump, for which the critical value of the viscosity of the pumped medium is determined. The implementation of this model was carried out by the finite volume method using the ANSYS engineering simulation software. The geometry of finite elements and the finite volume mesh generated, an analogue of a continuous computational domain, were constructed by the MESH preprocessor. The finite volume mesh consists of polyhedral elements. Using the model, the fields of temperature, velocity and viscosity were obtained throughout the entire volume of the area under study. The curves showing the dependence of the average temperature of the cross section on the longitudinal coordinate of the tubing and the dependence of the average temperature at the inlet to an electric centrifugal pump on the heater power are presented. The viscosity value at the maximum permissible temperature of the heater, as well as the value of sufficient heater power to ensure uninterrupted pumping of petroleum liquid, were determined. The results obtained can be used to significantly improve the operating efficiency of an electric centrifugal pump, to increase the turnaround time and to reduce material costs during field development.

Effect of temperature on the drag reduction characteristics of xanthan gum in the liquid ring vacuum pump

Xanthan gum (XG) solution has been proven to be an effective working fluid in the liquid ring vacuum (LRV) pump to achieve significant energy savings. As an important influencing factor of the LRV pump performance, the effect of temperature on the drag reduction performance, rheological properties, and microstructure of XG solution in the LRV pump were experimentally investigated in this paper. The results indicate that with the increase of temperature, the drag reduction rate of the XG solution in the LRV pump initially rise and subsequently decline, and XG solutions with different concentrations show different optimal drag reduction temperatures. The microscopic parallel double-chain structure of XG has the same change pattern as the drag reduction performance, while the steady-state and dynamic shear characteristics of the XG solution manifest a downtrend. For instance, as the temperature of 4000 ppm XG solution increases from 10 °C to 60 °C, the drag reduction rate decreases by 20 %; the parallel double-chain structure decreases from 91.3 % to 89.9 %; the yield stress and relaxation time decrease from 4.63993 Pa to 4477.56 s to 3.37808 Pa and 143.27 s, respectively; the drag reduction rate reaches the maximum value when the temperature is 40 °C.

Measurement of air-water counter-current flow rates in vertical annulus using multiple differential pressure signals and machine learning

Abstract Gas–liquid counter-current flow in vertical annulus is involved in several industrial fields such as petroleum engineering. For example, in coalbed methane wells with liquid pump drainage, obtaining the real-time flow rate of gas–liquid two-phase in the annulus is crucial for the development management of coalbed methane wells. However, due to complex flow conditions, this demand is difficult to achieve through traditional flow metering means. Therefore, this paper proposes a flow prediction method based on multi-group differential pressure signals and machine learning technology. Air-water two-phase flow experiments were carried out on a vertical annulus pipeline with inner and outer diameters of 75 mm/125 mm and adjustable eccentricity. The probability density function and power spectrum density of 3 groups of differential pressure signals collected at different height intervals in the annulus were used as model inputs. A gas–liquid two-phase flow prediction model was constructed based on the artificial neural network model, and the model hyper-parameters were optimized using Bayesian optimization. The results show that on the 440-group test dataset under the combined conditions of air superficial velocity of 0.06–5.04 m s−1, water superficial velocity of 0.03–0.25 m s−1, and pipeline eccentricity of 0, 0.25, 0.5, 0.75, 1, etc. This model can achieve average prediction errors of 9.12% and 29.34% for gas and water flow rates respectively. This method can be applied to the non-throttling, non-invasive measurement of phase flow rate under the condition of annulus air-liquid counter-current flow.

The Mechanism of Air Blocking in the Impeller of Multiphase Pump

The exploitation and transportation of deep-sea and remote oil and gas fields have risen to become important components of national energy strategies. The gas–liquid separation and gas blocking caused by the large density difference between the gas and liquid phases are the primary influencing factors for the safe and reliable operation of gas–liquid mixed transportation pump systems. This paper takes the independently designed single-stage helical axial-flow mixed transportation pump compression unit as the research object. Through numerical simulation, the internal flow of the mixed transportation pump is numerically calculated to study the aggregation and conglomeration of small gas clusters in the flow passage hub caused by gas–liquid phase separation, influenced by the shear flow of phase separation, forming axial vortices at the outlet where gas clusters gather in the flow passage. The work performed by the impeller on the gas clusters is insufficient to overcome the adverse pressure gradient formed at the outlet of the flow passage due to the gathering of the liquid phase in adjacent flow passages, resulting in the phenomenon of gas blocking, with vortex gas clusters lingering near the hub wall of the flow passage.

Economic evaluation of submerged anaerobic hybrid membrane bioreactor operating at mesophilic temperature.

A laboratory-scale mesophilic submerged anaerobic hybrid membrane bioreactor (An-HMBR) was operated for 270days for the treatment of high-strength synthetic wastewater at different hydraulic retention times (HRTs) (3days, 2days, 1day, and 0.5days). Chemical oxygen demand (COD) removal efficiency of 92% was obtained with methane yield rate of 0.18 LCH4/g CODremoval at 1-day HRT. The results of lab scale reactor at 1-day HRT were utilized for upscaling and cost analysis. Cost analysis revealed that the total capital cost comprised tank system (48%), membrane cost (32%), screen and PUF sponge (5% each), PLCs (4%), liquid pumps (3%), and others (2%). The operational cost comprised chemical cost (46%), pumping energy (42%), and sludge disposal (12%). The results revealed that the tank and heating costs accounted for the largest fraction of the total life cycle cost for full-scale An-HMBR. The heating cost can be compensated by gas recovery. Sensitivity analysis revealed that the interest rates, influent flow, and membrane flux were the most crucial parameters which affected the total cost of An-HMBR.

Effect of variable conditions on transient flow in a solid–liquid two-phase centrifugal pump

To investigate the influence of altering operational parameters on the transient flow characteristics within the flow channel of a solid–liquid two-phase centrifugal pump, this study employs a particle model based on the Euler–Euler method. Utilizing the standard k–e model, flow field simulations are conducted using the ANSYS-CFX software. Specifically, the study focuses on throttle regulation scenarios, monitoring and comparing the external and internal flow parameters of the solid–liquid two-phase pump with those of a clear water medium centrifugal pump. The results indicate notable modifications in head, efficiency, and shaft power due to the presence of solid particles in the two-phase flow. Decreasing flow rates during throttle regulation lead to fluctuations in pressure and turbulence energy distribution. Furthermore, under identical operational conditions, the variable working conditions of the solid–liquid pump result in increased flow rates of solid-phase particles near the impeller's outer edge, with particles shifting toward the middle and tail of the vane suction surface. This phenomenon exacerbates wear on the vane tail of the suction surface. Moreover, the study identifies that changing operational conditions in the solid–liquid dual-flow centrifugal pump contribute to increased axial forces, consequently leading to pump vibrations. Overall, this research elucidates the transient flow characteristics within the flow channel of solid–liquid two-phase centrifugal pumps under varied operational conditions, serving as a foundational reference for assessing the stability of such pumps.

Transcatheter Arterial Radioembolization–Induced Gastric Ulcer in an Excluded Stomach After Roux-en-Y Gastric Bypass

ABSTRACT Transcatheter arterial radioembolization (TARE) is a common locoregional treatment for hepatocellular carcinoma. It is associated with peptic ulcer disease in up to 5% of patients. A 70-year-old man with Roux-en-Y gastric bypass and liver cirrhosis with hepatocellular carcinoma treated with TARE 6 months earlier was evaluated for continued melena and was found to have an ulcer in the excluded stomach. This was successfully treated with liquid proton pump inhibitor through gastrostomy tube to the excluded stomach. This represents a unique case of successful management of TARE-induced peptic ulcer disease in the excluded stomach of a Roux-en-Y gastric bypass patient.

Solid-State Electromechanical Smart Material Actuators for Pumps—A Review

Solid-state electromechanical smart material actuators are versatile as they permit diverse shapes and designs and can exhibit different actuation modes. An important advantage of these actuators compared to conventional ones is that they can be easily miniaturized to a sub-millimeter scale. In recent years, there has been a great surge in novel liquid pumps operated by these smart material actuators. These devices create opportunities for applications in fields ranging from aerospace and robotics to the biomedical and drug delivery industries. Although these have mainly been prototypes, a few products have already entered the market. To assist in the further development of this research track, we provide a taxonomy of the electromechanical smart material actuators available, and subsequently focus on the ones that have been utilized for operating pumps. The latter includes unidirectional shape memory alloy-, piezoelectric ceramic-, ferroelectric polymer-, dielectric elastomer-, ionic polymer metal composite- and conducting polymer-based actuators. Their properties are reviewed in the context of engineering pumps and summarized in comprehensive tables. Given the diverse requirements of pumps, these varied smart materials and their actuators offer exciting possibilities for designing and constructing devices for a wide array of applications.

Modelling and analysis of a superconducting magnetic coupler used for cryogenic pump

AbstractIt is difficult to achieve low heat leakage and leak‐free rotary sealing for conventional small‐ and medium‐sized cryogenic liquid pumps (CLPs). This is because the motor in a room‐temperature environment is connected to the pump impeller (in a cryogenic environment) via a long transmission shaft. An axial flux‐concentration superconducting magnetic coupler (AFCSMC) is proposed for CLP to eliminate the transmission shaft. Firstly, the structure and the operation mechanism of AFCSMC are described. Then, a 2D electromagnetic modelling method for AFCSMC is established based on the H‐φ formulation and also validated experimentally in terms of the prediction on the levitation force and the guidance force. Thus, the 2D numerical simulations of AFCSMC are performed in an equivalent static system instead of the actual double rotor motion system in which the moving mesh is quite complicated. It is investigated that dependences of the transmission torque on the key electromagnetic structural parameters, such as permanent magnet arrangement, number of pole‐pairs, ferromagnetic yoke, operating slip, and so on. The results indicate that the average transmitting torque is less affected by the operating slip, and AFCSMC can start asynchronously and operate in steady state with a synchronous speed. With the advantages of low loss, risk‐free of desynchronising, and overload protection, the proposed AFCSMC can provide a competitive candidate for mechanical power transmission technologies in cryogenic engineering.