High Pump Research Articles

Combining measurements and simulation for condition monitoring and performance optimization of an alpha-configuration double-acting high-temperature Stirling cycle-based heat pump

For industrial applications, it is important to reliably monitor the condition of critical equipment and to run at optimal performance for varying operating conditions. Often important parameters for monitoring and optimization cannot be reliably measured and must be estimated. For example, there are great difficulties in measuring temperatures inside a Stirling cycle-based heat pump as these fluctuate between heating and cooling cycles at speeds of 10–12.5 Hz. Validation of models using full-scale industrial applications are very rare. We here present and validate a model for simulating cyclic temperature variations inside an industrial alpha-configuration double-acting Stirling cycle-based high temperature heat pump based on measured cylinder pressures and slow-changing temperature data. This will be used for online monitoring of the heat pump and as input to system performance optimization. The heat pump used as a reference is located in Gothenburg, Sweden with a design heat output of 500 kW and steam output at a temperature of 180 °C. The outputs of the model are temperature curves during a full cycle for both cold and hot side water and working fluid temperature variation in different parts of the machine. The model is validated against a different data set from the same system.

Potential evaluation of integrated high temperature heat pumps: A review of recent advances

Industrial and high temperature pumps are a well-established, sustainable, and low-emission technology for processing temperatures below 100 °C, especially when driven by renewable energy. The next frontier in heat pumping is to enhance the economic working envelope to serve the 100–200 °C range, where an estimated 27% of industrial process heat demand is required. High temperature heat pumps (HTHP) are an effective technology for delivering heat and recovering waste heat from various industrial processes, hence reducing primary energy consumption and the resulting CO2 emissions. The integration of high temperature heat pumps into different industrial process networks provides significant environmental and performance improvements,an innovative and profitable solution for different decarbonizing sectors. Higher temperature heat pumps offer significant potential to enhance thermally demanding industrial processes due to their high temperature lift capability. This review looks at how future improvements in HTHP technology can take use of breakthroughs in high-temperature heat pump research to address important technical obstacles. This review primarily consolidates data from HTHPs integrated with various industrial processes applications such as thermal energy storage, low-grade waste heat recovery, membrane fuel cell, organic Rankine cycle, super-critical water desalination, co-generation and poly-generation, vapor injection, steam injected gas turbine, and solar absorption system. However, the widespread diffusion of HP technologies faces several challenges, including technological (limitation of the electrical network due to intensive electrification of the heating sector), economic (high investment and installation cost), regulatory (lack of standards and mandatory policies), policy (uncertainty in policy and lack of clear heat decarbonization pathways and technology uptake), and public acceptance issues (unwarranted fear, misperception, misinformation, and previous experiences on the reliability of heat pumps) are highlighted.

In-situ measurement of the electron spin polarization by controlling its distribution in atomic ensembles.

The determination of electron spin polarization by controlling the atomic population distributions of ground states has been proposed. The polarization could be deduced by generating different population symmetries by polarized lights. The polarization of the atomic ensembles was decoded from optical depth in different transmissions of linearly and elliptic polarized lights. The feasibility of the method has been validated theoretically and experimentally. Moreover, the influences of relaxation and magnetic fields are analyzed. The transparency induced by high pump rates are investigated experimentally, and the influences of ellipticity of lights are also discussed. The in-situ polarization measurement was achieved without changing optical path of atomic magnetometer, which provides a new way to interrogate the performance of atomic magnetometer and in-situ monitoring the hyperpolarization of nuclear spins for atomic co-magnetometer.

Bio-SHARPE: Bioinspired Soft and High Aspect Ratio Pumping Element for Robotic and Medical Applications.

The advent of soft robots has solved many issues posed by their rigid counterparts, including safer interactions with humans and the capability to work in narrow and complex environments. While much work has been devoted to developing soft actuators and bioinspired mechatronic systems, comparatively little has been done to improve the methods of actuation. Hydraulically soft actuators (HSAs) are emerging candidates to control soft robots due to their fast responses, low noise, and low hysteresis compared to compressible pneumatic ones. Despite advances, current hydraulic sources for large HSAs are still bulky and require high power availability to drive the pumping plant. To overcome these challenges, this work presents a new bioinspired soft and high aspect ratio pumping element (Bio-SHARPE) for use in soft robotic and medical applications. This new soft pumping element can amplify its input volume to at least 8.6 times with a peak pressure of at least 40 kPa. The element can be integrated into existing hydraulic pumping systems like a hydraulic gearbox. Naturally, an amplification of fluid volume can only come at the sacrifice of pumping pressure, which was observed as a 19.1:1 reduction from input to output pressure. The new concept enables a large soft robotic body to be actuated by smaller fluid reservoirs and pumping plant, potentially reducing their power and weight, and thus facilitating drive source miniaturization. The high amplification ratio also makes soft robotic systems more applicable for human-centric applications such as rehabilitation aids, bioinspired untethered soft robots, medical devices, and soft artificial organs. Details of the fabrication and experimental characterization of the Bio-SHARPE and its associated components are given. A soft robotic squid and an artificial heart ventricle are introduced and experimentally validated.

Analysis of the thermophysical process within the SEOP polarized 3He system

Temperature is a crucial parameter in the spin-exchange optical pumping (SEOP) process of noble gas (3He), but is hard to measure due to its confinement nature. In this paper, we conduct research upon the temperature and gas flow distribution within a sealed SEOP cell through computational fluid dynamics simulation. The simulation result shows that the external heat exchange of the initial heating of the cell becomes a cooling process in the presence of high pumping laser power absorbed by the alkali metal. The heat from the pumping laser would also cause the gas in the cell to reach a much higher temperature than the oven, with the hottest part appearing on the upper side of the cell. These predicted behaviors from the simulation are later confirmed by our experiment measurement, which strongly indicates that a gas flow and heat flow exist within the cell. These results help us to understand the temperature distribution of 3He gas in the cell and provide references for the development and improvement of the future SEOP system.

A Front-End CMOS Interface Circuit With High Voltage Charge Pump and Oscillator for Capacitive Micromachined Ultrasonic Transducers

Label-free biosensors, combined with miniaturized micro-electromechanical sensory platforms, offer an attractive solution for real-time and facile monitoring of biomolecules due to their high sensitivity and selectivity without the need for specifically labeling. Resonators have been acknowledged as an efficient technology for measuring biomolecular binding events including those involving nucleic acid and antibody. Among these, capacitive micromachined ultrasonic transducers (CMUTs) have emerged as a promising candidate for biosensing. However, their usage is often limited by the requirement for high voltage supply and continuous frequency tracking, which can result in significant parasitic effects and measurement errors. In this paper, we present a novel front-end interface circuit for a CMUTs-based biosensor. The circuit, fabricated using TSMC 0.18-μX;Jm Bipolar-CMOS-DMOS (BCD) technology, incorporates an on-chip high voltage charge pump and feedback frequency monitoring. The CMUTs array features 20×20 circular cells, fabricated using a low-temperature direct bonding technology, with an experimental parallel-resonant frequency of 1.724 MHz and a high quality factor of up to 40.9. To fit the measured electrical characteristics, a five-element equivalent lumped element model is proposed. The high voltage charge pump provides an output voltage of 20 V, while the feedback oscillator has a ms-level start-up time and a total power dissipation of 3.8 mW. The proposed front-end interface is designed to function as a stand-alone chip for CMUTs-based resonant biodetection.

A high flow-rate single-chamber valveless piezoelectric pump with airfoil baffles

Valveless piezoelectric pumps have a simple structure and excellent reliability and are not harmful to the transmission medium. However, the output flow of such pumps is low, limiting their practical applicability. When fluid flows over airfoils in the forward or reverse direction, the flow resistance coefficient is unequal due to the different energy loss, and hence airfoils have the one-way cut-off performance. Therefore, airfoil baffles are integrated into the piezoelectric pump in this work, and a single-chamber valveless piezoelectric pump with airfoil baffles is proposed to research the possibility of increasing its output flow rate. The flow fields in three different airfoil tubes are simulated using the flow simulation software ANSYS CFX. The results show that the NACA0015 airfoil tube has the highest reverse-flow energy dissipation and the highest forward-to-reverse-flow energy dissipation ratio. Subsequently, three different valveless piezoelectric pump prototypes are fabricated and tested. Among them, the pump with the NACA0015 airfoil has the maximum flow rate, and the flow rate reaches 235.56 mL/min with a maximum output back pressure of 842.8 Pa when the driving voltage is 100 V. The study results are helpful to further optimize the structural design of valveless piezoelectric pumps, enhance their output performance, and improve their practicability.

Octopus-Inspired Suction Cup Array for Versatile Grasping Operations

Octopuses can use as few as a single sucker to grab and hold onto objects as each sucker creates its own vacuum pressure using their individual muscles. Man-made suction arrays using vacuum pressure need mechanical solutions such as check valves for every suction cup, or they need to compensate for air leakage using heavy high flow pumps. The system also needs to be modified depending on whether it is operating in the air or underwater. This makes man-made systems powerful if driven by the appropriate fluidic hardware, but the size of the system and its lack of versatility can be a problem. This paper introduces the design of an octopus-inspired suction cup array (OISCA) that consists of multiple suction cups with a single vacuum input channel and independent vacuum adhesion cavities through the use of flexible membranes separating the applied vacuum cavity from the cavity creating the adhesive force onto the objects. This paper shows that leaks only affect individual suction cups, that the OISCA can be used in air or underwater with the same pneumatic system, and that it can grab grooved, curved,or perforated objects even with multiple of its suction cups failing to make a seal.

Terahertz generation through optical rectification in reflection

In this paper, we study terahertz generation through optical rectification in reflection at normal incidence in a dielectric nonlinear crystal. We first analyze, with a nonlinear optical model, the sample parameters (thickness, absorption at both laser and terahertz wavelengths, etc.) for which a terahertz optical rectification reflection scheme is preferable to the common transmission scheme. Then, we report our experimental observations of a reflected terahertz signal generated at the surface of a ZnTe crystal. The reflected terahertz signal shares all the characteristics of a signal generated in transmission but is not limited by absorption losses in the crystal, thereby providing a broader bandwidth. At high pump laser power, the signal exhibits saturation, which is caused by the decrease of the nonlinear susceptibility due to photocarriers generated by two-photon absorption. This reflection scheme could be of great importance for terahertz microscopy of opaque materials like, e.g., humid samples or samples exhibiting strong absorption bands or to study samples for which the transmitted signal cannot be recorded.

Experimental study on performance evaluation of passive valved piezoelectric micropumps with series, parallel and hybrid series-parallel configuration

ABSTRACT To overcome the flow deficit in high pumping flow applications, a parametric study is presented involving three Multiple Micropump system (MMS) configurations: Series Multiple Micropump System (SMMS), Parallel Multiple Micropump System (PMMS) and hybrid Series-Parallel Multiple Micropump System (SPMMS). The performance of the MMS configurations was investigated using analytical and experimental approach. The MMS operating at ‘in-phase’ mode (0° phase difference) was observed to exhibit flow pulsations. Therefore, the MMS was operated at ‘out-of-phase’ mode (90° phase difference) to minimise the flow pulsations. The maximum flow rate at the ‘in-phase’ mode was observed to be 37.58 ml/min, 112.32 ml/min and 51.81 ml/min for SMMS, PMMS and SPMMS configurations respectively. Whereas the flow pulsation results indicate that the degree of flow pulsation for SMMS, PMMS and SPMMS configurations was decreased by 13.4%, 13.5% and 13.3% respectively when operated at ‘out-of-phase’ mode. The maximum back pressure of 140 kPa, 40 kPa and 100 kPa was recorded for SMMS, PMMS and SPMMS configurations respectively. It was found that the flow rate and backpressure vary significantly with the actuation frequency and series-parallel modes for MMS. The proposed series-parallel MMS configurations can be used in biomedical, thermal management and fuel cell applications.

Extremum seeking control for real-time optimization of high temperature heat pump systems incorporating vapor injection

In order to minimize the power consumption of a vapor-injected high temperature heat pump system with R245fa as refrigerant, a control strategy, namely Extremum seeking control, is proposed. It can implement real-time model-free optimization control of plants with concave and convex properties. Modelica-based dynamic simulation model of the proposed system is developed. The Newton-based Extremum seeking control is used to optimize the intermediate pressure of the proposed system to obtain the minimum power consumption of the compressor at a fixed heating capacity (200 kW). The adopted ESC strategy requires four measured quantities, namely, injection pressure, condenser outlet water temperature, evaporator outlet superheat and compressor power consumption, to achieve optimal control of the system in real time. Two operation scenarios are simulated: stable and freely variable heat source temperature. For both scenarios, the condenser outlet water temperature was set to 140 °C. The simulation results show that at stable heat source temperature, the power consumption is reduced by 5.2% and the COP is increased by 7.7% compared to a fixed initial intermediate pressure. Under the free-variable heat source condition, the power consumption can be reduced by up to 5 kW compared to a constant input. A total of 283 kWh of power was saved during the 48 h simulation. Thus, the Newton-based extremum seeking control strategy can optimize the intermediate pressure to achieve the minimum power consumption while maintaining excellent transient performance, and demonstrate the superiority of the ESC strategy for real-time optimization..

Method Development and Validation of Lorazepam by Using RP-HPLC in Pharmaceutical Formulation

High pressure liquid chromatography (RP-HPLC) is a column chromatographic technique employing high pressure pump to pass both mobile phase and sample mixture through stationary phase column and perform efficient separation. A C-18 column with mobile phase containing Acetonitrile: methanol (80: 20) was used. The flow rate was 1.0ml/min. and were monitored at 210 nm. The retention time for Lorazepam was 1.3 min. The method was validated for linearity, accuracy, precision, limit of detection. The Mean percent recovery of Lorazepam from tablet formulation was found to be 94.80 %.

Multi-variable extremum seeking control for high temperature heat pump system incorporating double refrigerant injection

The use of refrigerant injection technology to enhance the heating efficiency of heat pumps with larger temperature lifts is becoming more common. Heat pumps with double refrigerant injection loops have better energy efficiency than traditional ones with single refrigerant injection loops. A multi-variable extremum seeking control (ESC) strategy for a high-temperature heat pump system with double refrigerant injection technology is proposed in this study. A Modelica-based dynamic simulation model of the considering system is established in Dymola, and a co-simulation with the proposed ESC strategy is built to validate the effectiveness of this control strategy to minimize power consumption. The strategy uses compressor power consumption as the feedback. The effective throttling area of the upper and lower EEVs is adjusted by a PI controller to manipulate the low and high-pressure vapor injection pressures. Three scenarios were simulated for control: stable, step curve, and freely variable heat source temperature conditions. The simulation results demonstrate that the multi-variable ESC has excellent convergence performance and confirm its effectiveness in searching for the optimal operating point.

Highly anisotropic transient optical response of charge density wave order in ZrTe3

Low dimensionality in CDW systems leads to anisotropic optical properties, in both equilibrium and non-equilibrium conditions. Here we perform polarized two-color pump probe measurements on a quasi-1D material ZrTe$_3$, in order to study the anisotropic transient optical response in the CDW state. Profound in-plane anisotropy is observed with respect to polarization of probe photons. Below $T_\mathrm{CDW}$ both the quasi-particle relaxation signal and amplitude mode (AM) oscillation signal are much larger with $\mathbf{E}_\mathrm{pr}$ nearly parallel to $a$ axis ($\mathbf{E}_\mathrm{pr} \parallel a$) than for $\mathbf{E}_\mathrm{pr}$ parallel to $b$ axis ($\mathbf{E}_\mathrm{pr} \parallel b$). This reveals that $\mathbf{E}_\mathrm{pr} \parallel a$ signal is much more sensitive to the variation of the CDW gap. Interestingly, the lifetime of the AM oscillations observed with $\mathbf{E}_\mathrm{pr} \parallel b$ is longer than $\mathbf{E}_\mathrm{pr} \parallel a$. Moreover, at high pump fluence where the electronic order melts and the AM oscillations vanish for $\mathbf{E}_\mathrm{pr} \parallel a$ , the AM oscillatory response still persists for $\mathbf{E}_\mathrm{pr} \parallel b$. We discuss possible origins that lead to such unusual discrepancy between the two polarizations.

Automated, high temporal resolution mechanics measurements during incubation of contractile tissues

Muscle tissue mechanics and contractility measurements have a great advantage over cultured cell level experiments as their mechanical and contractile properties are much closer to in vivo tissue properties. However, tissue level experiments cannot be combined with incubation with the same time resolution and consistency as cell culture studies. Here we present a system in which contractile tissues can be incubated for days while intermittently being tested for their mechanical and contractile properties. A two-chamber system was developed with control of temperature in the outer chamber and CO2 and humidity control in the inner, sterile chamber. Incubation medium, to which biologically active components may be added, is reused after each mechanics test to preserve both added and released components. Mechanics and contractility are measured in a different medium to which, through a high accuracy syringe pump, up to 6 different agonists in a 100-fold dose range can be added. The whole system can be operated through fully automated protocols from a personal computer. Testing data shows accurate maintenance of temperature, CO2 and relative humidity at pre-set levels. Equine trachealis smooth muscle tissues tested in the system showed no signs of infection after 72 h with incubation medium replacement every 24 h. Methacholine dosing and electrical field stimulation every 4 h showed consistent responses. In conclusion, the developed system is a great improvement on the manual incubation techniques being used thus far, improving on time resolution, repeatability and robustness, while reducing contamination risk and tissue damage from repeated handling.

Effect of Heat Input Condition on Evaporator to the Performance of High Temperature Heat Pump

Effect of Heat Input Condition on Evaporator to the Performance of High Temperature Heat Pump

Optical Saturation Produces Spurious Evidence for Photoinduced Superconductivity in K_{3}C_{60}.

We discuss a systematic error in time-resolved optical conductivity measurements that becomes important at high pump intensities. We show that common optical nonlinearities can distort the photoconductivity depth profile, and by extension distort the photoconductivity spectrum. We show evidence that this distortion is present in existing measurements on K_{3}C_{60}, and describe how it may create the appearance of photoinduced superconductivity where none exists. Similar errors may emerge in other pump-probe spectroscopy measurements, and we discuss how to correct for them.

The effect of polyethylene butene (PEB) and xylene on the shear stress of Niger delta crude oil

Crude oil production and transportation is plagued by several flow assurance issues especially in offshore environment with prevailing low temperature. One of the flow assurance challenges is the deposition of paraffin wax which usually changes the crude oil flow from Newtonian fluid flow to non- Newtonian fluid flow with increased viscosity. This increased viscosity can impede flow causing the installation of high horsepower pumps for fluid flow. In severe cases, paraffin wax has plugged the pipes and caused production disruption. It is therefore imperative to manage paraffin disposition in crude samples containing paraffin compounds (C18+). This research discusses the use of varying concentrations of Polyethylene Butene (PEB) in managing wax precipitation at various temperatures (10 °C to 35 °C) at a constant shear rate of 511(s-1). The reduction in crude oil temperature increased the shear stress in all experiments conducted. It was discovered that the increasing concentration of PEB from 500ppm to 5000ppm had a sinusoidal effect on reducing the shear stress. 500ppm of PEB effected a 19% reduction in shear stress, while 5000ppm effected a 35% reduction in shear stress. It is important for the engineer to make the choice of inhibitor concentration based on the degree of shear stress reduction required to optimize inhibitor usage.

Experimental Characterization of an NEG Pump of Novel Size—A Major Step toward Its Application in DEMO Neutral Beam Injectors

A future nuclear fusion plant DEMO needs neutral beam injection (NBI) systems requiring a vacuum pumping system with a very high pumping speed, in the order of several 1000 m3/s. Large customized cryopumps are actually used to meet the requirements. A promising concept for future NBI systems is based on high capacity getter materials. The ZAO® alloy, developed by SAES Getters, Italy, provides a drastically improved performance for the pumping of hydrogen compared to conventional getter materials. This paper describes the experimental characterization of a large pump of scalable size with 15 kg of ZAO® and the achieved results, in particular the systematic investigation of sorption characteristics and regeneration behaviors. Major findings include a very good repeatability of the sorption performance, a reduced pumping speed at higher pressures only above the NBI relevant level, an improved performance (+20%) with elevated getter temperature and an isotope independent sticking coefficient for hydrogen. Furthermore, improved operation experience and regeneration prediction tools have been developed. Employing the experimental results, a simulation task was performed and the sticking factor of the getter cartridge was determined with 7%.

Climate Change Impact on Groundwater-Based Livelihood in Soan River Basin of Pakistan (South Asia) Based on the Perception of Local Farmers

Based on the perceptions of the local farmers, this study aims to assess the effects of socioeconomic factors and climatic change on the groundwater livelihood system, with a particular focus on in situ Persian wheels/dug wells. Farmers’ perceptions of climate change and how it is affecting their way of life in the Soan River Basin have also been evaluated to determine the most appropriate adaptive interventions. Information and literature about dug wells was unavailable, which stressed the need to carry out this survey. A structured close-ended questionnaire was designed and administered with as much quantitative data as possible. Random sampling opted for a 5 km buffer zone across the Soan River and its tributaries. Union councils having more than 50% of their area lying in the buffer zone were surveyed, and data was collected. Fifty UCs fell within this criterion, and six dug wells from each Union Council were surveyed. The results of our survey collecting local farmer’s perceptions determined that about 70% of respondents agreed about climate change in the Soan Basin of Pakistan, and 62% of farmers reported that climate change severely impacted their livelihood by affecting agricultural productivity and water availability. Ninety-two percent reported summer becoming hot, 72% highlighted that winters are becoming less cold, and 96% reported that average annual rainfall has decreased compared to 10 years before. About 72% of respondents indicated that available water in their dug wells had decreased, and 80% of respondents explained that their crop yield had decreased compared to 10 years before. Sixty percent preferred drip and 35% sprinkler irrigation as efficient water management practices to cope with water shortages. Ninety-five percent of farmers were ready to use solar pumps for irrigation to tame high pumping costs. The study recommends integrating solar pumping with drip and sprinkler irrigation systems to enhance farmers’ cropped area and productivity. These vulnerable farmers can enhance their resilience and profitability by adopting high-value agriculture (tunnel farming, off-season vegetables, etc.) instead of conventional crops.