Commercial Pump Research Articles

Thermal effectiveness of active caloric regenerators

Caloric materials respond to external field variations such as magnetic, stress, and electric. A simple caloric cycle uses entropy and temperature changes resulting from a single field variation to provide useful transfers of work and heat. An active regenerator cycle increases operating range and efficiency of a caloric material when property variations are appropriately matched to design conditions. However, the variability of material properties, wide range of design variables, and non-linear interactions complicate design of devices. Simplified analytic models are needed to increase understanding and quantify potential of calorics for commercial heat pumps and engines. An analytic model of a generic active caloric regenerator operating as a heat pump or engine is described. A thermal effectiveness is defined as an analytic function of operating, design, and material parameters.

Recovery and Utilization of Low-Grade Waste Heat in the Oil-Refining Industry Using Heat Engines and Heat Pumps: An International Technoeconomic Comparison

We assess the technoeconomic feasibility of onsite electricity and steam generation from recovered low-grade thermal energy in oil refineries using organic Rankine cycle (ORC) engines and mechanical vapour compression (MVC) heat pumps in various countries. The efficiencies of 34 ORC and 20 MVC current commercial systems are regressed against modified theoretical models. The resulting theoretical relations predict the thermal efficiency of commercial ORC engines within 4–5% and the coefficient of performance (COP) of commercial MVC heat pumps within 10–15%, on average. Using these models, the economic viability of ORC engines and MVC heat pumps is then assessed for 19 refinery streams as a function of heat source and sink temperatures, and the available stream thermal energy, for gas and electricity prices in selected countries. Results show that: (i) conversion to electrical power with ORC engines is, in general, economically feasible for heat-source temperatures >70 °C, however with high sensitivity to energy prices; and (ii) steam generation in MVC heat pumps, even more sensitive to energy prices, is in some cases not economical under any conditions—it is only viable with high gas/low electricity prices, for large heat sources (>2 MW) and higher temperatures (>140 °C). In countries and conditions with positive economics, payback periods down to two years are found for both technologies.

New Chemoresistive Gas Sensor Arrays for Outdoor Air Quality Monitoring: A Combined R&D and Outreach Activities

New Chemoresistive Gas Sensor Arrays for Outdoor Air Quality Monitoring: A Combined R&D and Outreach Activities

Low-cost FloPump for regulated air sampling of volatile organic compounds.

PremiseWe present a low‐cost, battery‐operated, portable pump, “FloPump,” which allows regulated air sampling for the study of volatile organic compounds (VOCs). VOCs are routinely investigated in applications such as atmospheric chemistry, agriculture, and fragrance biology.Methods and ResultsWe compared the performance of FloPump with the Supelco pump in collecting VOCs using two test samples: guava fruit (Psidium guajava) and a perfume. The sampling and identification of volatiles was carried out using a dynamic headspace sampling method followed by gas chromatography–mass spectrometry. We show that the sampling efficiency of FloPump is comparable to the commercial pump, and at an affordable cost of ~US$115 (~86% cheaper), it provides a viable option for researchers interested in sampling volatiles on a constrained budget.ConclusionsAccurate air sampling is critical for the study of VOCs. We propose that FloPump will make air sampling more affordable, thus encouraging studies of VOCs.

Investigating the performance of a thermal energy storage unit with paraffin as phase change material, targeting buildings’ cooling needs: an experimental approach

Abstract For the reduction of the electricity cost for cooling buildings in hot climate zones, thermal energy storage at low temperature using phase change materials is a potential solution. The storage medium can be cooled during periods of low electricity cost and then absorb the cooling load any time of the day. In this study, an experimental cold thermal energy storage system using organic phase change materials (A9 and A14) with melting temperature of 9 or 14 °C is investigated. The system is designed for real application conditions coupled with a heat pump which cools down the organic material through the circulation of water in the pipes and fan coil units which dissipate their thermal load in the initially cooled storage medium. It comprises of a thermal energy storage tank, inside which is positioned a staggered heat exchanger with finned tubes immersed in phase change material. The results from the experiments yielded shorter process duration (for both melting and solidification) and higher heat transfer rate when the feed rate was higher. Moreover, the temperature of the water entering and exiting the tank is more than 5 °C for A9 organic material for more than half the capacity of the tank thus, using A9, the fan coil units can operate efficiently for a long time. The heat transfer rate exceeds 5 kW for 32 and 24 min using A9 and A14 respectively and the thermal load that the tank can absorb from the fan coils is above 6 kWh per tank. During the heat pump operation, A9 results to a more constant water outlet temperature over the time compared to A14 which in addition is not affected significantly by the water flow rate. Moreover, the staggered heat exchanger transfers less than 10 kW of heat when the water outlet temperature ranges between 5 and 10°C, a power value which can easily be provided by a typical commercial heat pump.

Optimización energética de bombas centrífugas a través de un análisis paramétrico en CFD y modelos de pérdida de energía

Introducción− La optimización energética de bombas centrífugas comprende diversas formas de estudio, entre ellas, la aplicación de análisis paramétricos sobre una bomba centrífuga comercial, generando cambios dimensionales que puedan ser estudiados a través de CFD y que permitan obtener una configuración paramétrica con mejores niveles de eficiencia. Adicionalmente, la incorporación de modelos de pérdida de energía sobre los análisis paramétricos, permite comprender de forma más detallada las causas de reducción de eficiencia bajo distintas condiciones de operación. Objetivo− En este estudio se busca optimizar una bomba centrifuga usando análisis paramétrico en CFD y modelos de perdida de energía, con el fin de mejorar la eficiencia energética. Metodología− Se realizó un análisis energético que combina estudios paramétricos y modelos de pérdida de energía, aplicando la dinámica de fluidos computacional (CFD) por medio del software OpenFOAM. Los modelos constaron de 4 configuraciones geométricas: número de álabes, diámetro de salida, ángulo de salida y espesor de salida del impeler. Los modelos energéticos para el estudio de pérdidas de energía se basaron en turbulent kinetic energy (TKE) y el comportamiento de la eficiencia hidráulica. Resultados− Finalmente, se obtuvo que el parámetro que tuvo mayor influencia en la eficiencia y la turbulencia fue el aumento del espesor, disminuyendo las pérdidas de energía más influyentes sobre el desempeño de la bomba, logrando aumentos en la eficiencia de 4.71% y reducción de la TKE en 4.24 m2/s2 respecto a la bomba original. Conclusiones− La interface entre el impulsor y la voluta genera turbulencia por el gradiente de velocidad presente en las partículas, debido a que pasan de altas velocidades a un medio de baja velocidad. Las configuraciones que aumentaban el área de flujo entre los álabes presentaban mayores niveles de eficiencia, al permitir desplazar una mayor cantidad de fluido, permitiendo un comportamiento de las velocidades más adecuado, reduciendo las pérdidas debida a la fricción del fluido con las paredes de la voluta.

Adsorption gas Heat Pump fuelled with hydrogen enriched natural gas blends: the analytical simulation model development and validation

This study deals with the implementation of an analytical model to simulate the energy performance associated to a commercial Gas adsorption Heat Pump, when H2NG (Hydrogen Enriched Natural Gas) blends are used as fuel. In detail, a water source heat pump manufactured by Robur (GAHP-WS) has been used as a reference device for building the simulation model within the MATLAB-Simulink environment. Thereafter, the simulation results have been validated by the experimental campaign, testing on field and in actual operating conditions the heat pump. Specifically, the model has been developed by implementing the WaterAmmonia mass and energy balances for each component. It is able to evaluate fuel consumption, efficiency in terms of GUE, required thermal power from the cold heat sink as well as the water outlet temperature at the evaporator, once the heating load is used as the main input. The experimental campaign for the model calibration and validation has been carried out over the winter season. Additionally, the heat pump performance has been detected when it operates to supply hot water at 60 °C and 55 °C, and it is fuelled with growing hydrogen fractions, starting from 0% vol., 5% vol. up to 10% vol. In the end, the standard errors as well as the relative ones affecting the main output parameters have computed for the validation process. From the outcomes it emerges that the average relative standard error related to all load conditions is lower than 2.5% for natural gas operation. On the contrary, it ranges between 2.5% and 4% when H2NG at 5% and 10% by volume have been burnt.

Pump Efficiency Analysis for Proper Energy Assessment in Optimization of Water Supply Systems

Water supply systems need to be designed accounting for both construction and operational costs. When the installation requires water pumping, it is key for the operational costs to know how well the pump can perform. So far, pump efficiency has been considered using conservative values, in the absence of a better estimation. The aim of this paper was to improve determining the energy costs by clarifying what the value of the pump performance should be. For this, 226 commercial pumps were studied, registering the efficiency at the optimum operating point, as well as other variables such as the flow rate, height, and pump type. As a result, a strong relationship between the pump performance and the discharge flow was spotted. That allowed the generation of an empirical curve, which can be used by designers to anticipate what pump efficiency can be expected. The results are used in a simple case study using the Granados Optimization System. These achievements can be implemented in design policies for a better energy assessment in the optimization of water supply systems.

Experimental Assessment of the Potential Demand and Energy Reduction by Retrofitting a Boiler With a Commercial Air Source Heat Pump at a Students’ Residence on University Campus

Sanitary hot water consumption in the University residence contributes to a significant power and energy usage in relation to the energy consumed by other electrical devices. The study focused on retrofitting a 12kW boiler with two 1000 L storage tanks, with a 4.0 kW commercial air source heat pump (ASHP) unit to provide sanitary hot water at 55oC. A data acquisition system was built and employed in monitoring the operating performance of the electric boiler prior to intervention as well as operating performance of the ASHP water heater after the intervention. The results revealed that for the electric boiler, the average daily volume of hot water consumed was 1865 L, with an average power and energy consumption as well as load factor of 12.13 kW, 133.85 kWh and 0.464, respectively. In addition, the average daily volume of hot water consumed by the air source heat pump water heater was 1848 L while the average power, the average energy consumed and the load factor were 4.41 kW, 41.45 kWh and 0.370, respectively. We could conclude without reservation, that by retrofitting the electric boiler with a heat pump in a student residence (occupied by 75 female postgraduate students) on the University campus, an average daily energy saving of 94.40 kWh and a load factor reduction of 0.124 was realized while the average daily coefficient of performance was 3.10.

A portable plug-and-play syringe pump using passive valves for microfluidic applications

Portable and autonomous pumps are in critical demand for low-cost point-of-care testing (POCT) applications in microfluidic fields. In microfluidic laboratories, commercial pumps (e.g., syringe pumps, pressure pumps, or peristaltic pumps) are widely used for precise fluid delivery, however they can’t be integrated into miniaturized microfluidic devices due to their bulky sizes and high costs. Here, we propose a portable plug-and-play syringe pump with autonomous flow delivery function. Fluid stored in the pump is driven by a specially designed compression spring mechanism, and it is controlled by a microfluidic flow regulatory chip which contains three passive valves. Importantly, the liquid flow rate through the passive valve is independent of the fluidic pressure induced by the varied spring compression force, and constant flow autoregulation is realized through the microfluidic flow regulatory chip in the pump. This feature has been used for providing steady fluid infusions for passive sample mixing in a T-junction microfluidic mixer or high efficiency particle separation in an inertial microfluidic chip. We envision that the self-sufficient and portable plug-and-play syringe pump will facilitate the miniaturization of microfluidic systems which will shed light on the large-scale application of microfluidic technologies.

Effect of heat capacity modulation of heat pump to meet variable hot water demand

This paper analyzes the results of experimental studies of an Air Source Heat Pump (ASHP) for Domestic Hot Water (DHW). The tests were carried out by using a commercial heat pump in real conditions in Poland. The modular heat pump with ON/OFF compressor was additionally expanded with a variable speed rotary compressor. Two 130 dm3 water tanks were connected to the condenser output of the heat pump. The COP and heating capacity of the ASHP were investigated under different compressor speeds, water flow rates and different hot water temperatures in the condenser and different outside air temperatures in the evaporator.The DHW was heated in a storage tank whose temperature was changing from room temperature to a temperature above 50 °C. The ASHP subsystem was analyzed for the DHW heating in a typical family of four (130 dm3 at 50 °C, about 6 kWh per day). The test results show that the heating capacity has an approximately linear and proportional relationship with the speed of the compressor. A proportional increase in input power demand was also observed with an increase in compressor speed and refrigerant condensing temperature.

Verification Templates for the Analysis of User Interface Software Design

The paper describes templates for model-based analysis of usability and safety aspects of user interface software design. The templates crystallize general usability principles commonly addressed in user-centred safety requirements, such as the ability to undo user actions, the visibility of operational modes, and the predictability of user interface behavior. These requirements have standard forms across different application domains, and can be instantiated as properties of specific devices. The modeling and analysis process is carried out using the Prototype Verification System (PVS), and is further facilitated by structuring the specification of the device using a format that is designed to be generic across interactive systems. A concrete case study based on a commercial infusion pump is used to illustrate the approach. A detailed presentation of the automated verification process using PVS shows how failed proof attempts provide precise information about problematic user interface software features.

The Effect of Irrigation Power and Ureteral Access Sheath Diameter on the Maximal Intra-Pelvic Pressure During Ureteroscopy: In Vivo Experimental Study in a Live Anesthetized Pig.

Objectives: To assess the effect of irrigation settings and the size of ureteral access sheath (UAS) on the maximal intra-pelvic pressure (IPPmax) during ureteroscopy (URS) in pigs. Materials and Methods: In supine position, three anesthetized female pigs underwent cystoscopy to insert a 6F ureteral catheter in each ureter. Pigs were then turned to prone position to establish a percutaneous access, insert a 10F nephrostomy tube in the kidney, and connect it to a urodynamic device. An 8F semi-rigid ureteroscope or the Flex-X2 Flexible Ureteroscope was used with two irrigation settings: gravity flow and manual pumping using a commercial pump. URS was performed without UAS and with the UAS 9.5/11, 12/14, 14/16 at the ureteropelvic junction and the IPPmax was recorded. Results: Under gravity irrigation, the recorded IPPmax during semi-rigid URS in the distal ureter and the renal pelvis was 0 and 30 cmH2O, respectively. Further, the IPPmax during flexible URS in the renal pelvis without UAS, with UAS 9.5/11.5, with UAS 12/14, and with UAS 14/16 was 23, 6, 2, and 1 cmH2O, respectively. Under manual pumping, the IPPmax during semi-rigid URS in the distal ureter and the renal pelvis was 84 and 105 cmH2O, respectively. Further, the IPPmax during flexible URS in the renal pelvis without UAS, with UAS 9.5/11.5, with UAS 12/14, and with UAS 14/16 was 45, 46, 18, and 1 cmH2O, respectively. Conclusion: Manual pumping can significantly increase the IPPmax to unsafe levels during URS. The UAS can significantly decrease the IPPmax, even under manual pumping. The larger the UAS, the lower the IPPmax. The use of UAS can render URS safer by acting as a safeguard against the consequences of increased IPP, even under forced irrigation.

Performance improvement of cryosorption pump by enhancing thermal conductivity of epoxy-aluminum composite

Cryosorption pumps are only possible solution to pump helium gas in Tokamak. In this paper, we report the performance improvement of cryosorption pump, whose pumping speeds are increased by enhancing the thermal conductivity of epoxy by mixing fine aluminium powder as filler into it. From experimental studies it is found that 35% volume fraction of filler in epoxy adhesive is optimum for the improved thermal conductivity without reduction of the bonding strength. The pumping speed of cryosorption pump is increased by 3.60 times for helium gas when compared to identical commercial cryosorption pump.

Novel High-Power, High Repetition Rate Laser Diode Pump Modules Suitable for High-Energy Class Laser Facilities

The latest generation of high-energy-class pulsed laser facilities, under construction or planned, such as EuPRAXIA, require reliable pump sources with high power (many kW), brightness (>1 MW/cm2/sr) and electro-optical conversion efficiency (>50%). These new facilities will be operated at high repetition rates (around 100 Hz) and only diode lasers are capable of delivering the necessary performance. Commercial (quasi-continuous wave, QCW) diode laser pulse-pump sources are, however, constructed as low-cost passively cooled stacked arrays that are limited either in brightness, efficiency or repetition rate. Commercial continuous wave diode laser pumps constructed using microchannel coolers (as used in high-value industrial machine tools) can fulfil all requirements, but are typically not preferred, due to their cost and complexity and the challenges of preventing cooler degradation. A custom solution is shown here to fill this gap, using advanced diode lasers in a novel passive side-cooling geometry to realize 100 … 200 Hz pump modules (10%–20% duty cycle) that emit peak power of 6 kW at wavelength = 940 nm. The latest performance of these modules is summarized and compared to literature. We show that a brightness >1 MW/cm2/sr can be efficiently delivered across a wide range of laser pulse conditions with 10% duty cycle (pulse width: 100 µs … 100 ms … cw, repetition rate up to 1 kHz). Furthermore, we describe how these pumps have been used to construct and reliably operate (>109 pulses without degradation) in high-energy-class regenerative and ring amplifiers at the Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (MBI). We also show first results on 100 Hz pumping of cryogenically cooled solid-state Yb:YAG slab amplifiers, as anticipated for use in the EuPRAXIA laser, and note that peak temperature is disproportionately increased, indicating that improved cooling and more detailed studies are needed.

High-Efficiency Axial Pumps for Reactor Use

The flow of viscous liquid in highly efficient commercial axial pumps is hydrodynamically analyzed. Design recommendations are made regarding the flow sections of the pump, so as to ensure a pressure characteristic with no descending section and efficient coolant circulation in a fast-neutron reactor.

Evaluation of the Hydro—Mechanical Efficiency of External Gear Pumps

This paper proposes and describes a model for evaluating the hydro-mechanical efficiency of external gear machines. The model is built considering and evaluating the main friction losses in the machines, including the viscous friction losses at the tooth tip gap, at the bearing blocks-gears gaps, at the journal bearings, and the meshing loss. To calculate the shear stress at each gap interface, the geometry of the gap has to be known. For this reason, the actual position of the gears inside the pump casing and consequent radial pressure distribution are numerically calculated to evaluate the gap height at the tooth tips. Moreover, the variation of the tilt and reference height of the lateral gaps between the gears and the pump bushings are considered. The shear stresses within the lateral gaps are estimated, for different lateral heights and tilt values. At the journal bearings gaps, the half Sommerfeld solution has been applied. The meshing loss has been calculated according to the suggestion of the International Standards. The hydro-mechanical efficiency results are then discussed with reference to commercial pumps experimentally characterized by the authors in a previous work. The average percentage deviation from experimental data was around 2%, without considering the most critical operating conditions (high delivery pressure, low rotational speed). The limits of this approach are also explained. Finally, the role of each source of loss is discussed, considering different operating conditions and two values of fluid viscosity. Lateral gap losses and meshing loss are much more relevant in determining the hydro-mechanical efficiency variation in the pump’s operating range, especially at a low delivery pressure. Moreover, while lateral gap losses increase with the rotational speed, the meshing loss shows the opposite behavior. The tooth tip gap losses are never as relevant, but they increase at high pressure. The journal bearings losses become comparable with the lateral and meshing ones at high delivery pressure values. Considering the pumps analyzed and the operating range of delivery pressure values and rotational speed values, the meshing loss made the mechanical efficiency vary in a percentage range of ±7%, with lateral losses in the range of about the ±15%, when also considering the extreme operating points (low speed, high pressure; high speed, low pressure). The weight of the lateral losses slightly reduced when we analyzed the higher temperature results, while the meshing losses slightly increased.

An automated and parallelised DIY-dosing unit for individual and complex feeding profiles: Construction, validation and applications

Since biotechnological research becomes more and more important for industrial applications, there is an increasing need for scalable and controllable laboratory procedures. A widely used approach in biotechnological research to improve the performance of a process is to vary the growth rates in order to find the right balance between growth and the production. This can be achieved by the application of a suitable feeding strategy. During this initial bioprocess development, it is beneficial to have at hand cheap and easy setups that work in parallel (e.g. in shaking flasks). Unfortunately, there is a gap between these easy setups and defined and controllable processes, which are necessary for up-scaling to an industrial relevant volume. One prerequisite to test and evaluate different process strategies apart from batch-mode is the availability of pump systems that allow for defined feeding profiles in shaking flasks. To our knowledge, there is no suitable dosing device on the market which fulfils the requirements of being cheap, precise, programmable, and parallelizable. Commercially available dosing units are either already integrated in bioreactors and therefore inflexible, or not programmable, or expensive, or a combination of those. Here, we present a LEGO-MINDSTORMS-based syringe pump, which has the potential of being widely used in daily laboratory routine due to its low price, programmability, and parallelisability. The acquisition costs do not exceed 350 € for up to four dosing units, that are independently controllable with one EV3 block. The system covers flow rates ranging from 0.7 μL min-1 up to 210 mL min-1 with a reliable flux. One dosing unit can convey at maximum a volume of 20 mL (using all 4 units even up to 80 mL in total) over the whole process time. The design of the dosing unit enables the user to perform experiments with up to four different growth rates in parallel (each measured in triplicates) per EV3-block used. We estimate, that the LEGO-MINDSTORMS-based dosing unit with 12 syringes in parallel is reducing the costs up to 50-fold compared to a trivial version of a commercial pump system (~1500 €) which fits the same requirements. Using the pump, we set the growth rates of a E. coli HMS174/DE3 culture to values between 0.1 and 0.4 h-1 with a standard deviation of at best 0.35% and an average discrepancy of 13.2%. Additionally, we determined the energy demand of a culture for the maintenance of the pTRA-51hd plasmid by quantifying the changes in biomass yield with different growth rates set. Around 25% of total substrate taken up is used for plasmid maintenance. To present possible applications and show the flexibility of the system, we applied a constant feed to perform microencapsulation of Pseudomonas putida and an individual dosing profile for the purification of a his-tagged eGFP via IMAC. This smart and versatile dosing unit, which is ready-to-use without any prior knowledge in electronics and control, is affordable for everyone and due to its flexibility and broad application range a valuable addition to the laboratory routine.

Experimental Study on Demand Response by use of Commercial Heat Pump Water Heater in Spa Facility

Experimental Study on Demand Response by use of Commercial Heat Pump Water Heater in Spa Facility

A Wearable Closed-Loop Insulin Delivery System Based on Low-Power SoCs

The number of patients living with diabetes has increased significantly in recent years due to several factors. Many of these patients are choosing to use insulin pumps for their treatment, artificial systems that administer their insulin and consist of a glucometer and an automatic insulin supply working in an open loop. Currently, only a few closed-loop insulin delivery devices are commercially available. The most widespread systems among patients are what have been called the “Do-It-Yourself Hybrid Closed-Loop systems.” These systems require the use of platforms with high computing power. In this paper, we will present a novel wearable system for insulin delivery that reduces the energy and computing consumption of the platform without affecting the computation requirements. Patients’ information is obtained from a commercial continuous glucose sensor and a commercial insulin pump operating in a conventional manner. An ad-hoc embedded system will connect with the pump and the sensor to collect the glucose data and process it. That connection is accomplished through a radiofrequency channel that provides a suitable system for the patient. Thus, this system does not require to be connected to any other processor, which increases the overall stability. Using parameters configured by the patient, the control system will make automatic adjustments in the basal insulin infusion thereby bringing the patient’s glycaemia to the target set by a doctor’s prescription. The results obtained will be satisfactory as long as the configured parameters faithfully match the specific characteristics of the patient. Results from the simulation of 30 virtual patients (10 adolescents, 10 adults, and 10 children), using a python implementation of the FDA-approved (Food and Drug Administration) UVa (University of Virginia)/Padova Simulator and a python implementation of the proposed algorithm, are presented.