Dual Pump Research Articles

Investigating dehumidification and heating performance in a dual evaporator heat pump system for electric vehicles

In cold, moisture-rich winter environments, window fogging represents a substantial safety hazard for drivers. Electric vehicles often incorporate heat pump systems to address challenges such as dehumidification and heating specific to cold weather. Therefore, it is essential to evaluate the dehumidification and heating efficiency of these systems through focused research. This study presents a dual-evaporator heat pump system designed specifically for electric vehicles, equipped with two distinct modes for dehumidification and heating. The research examines how factors such as inlet air volume and the degree of opening of the electronic expansion valve affect the system's dehumidification and heating performance. Experimental analyses were conducted to explore the system's response under various conditions of inlet air humidity and compressor speed in both modes. Results suggest that increasing inlet air volume improves dehumidification effectiveness but may reduce heating performance. Likewise, a wider opening of the electronic expansion valve enhances heating but could decrease dehumidification efficiency. Importantly, the study indicates that when the relative humidity of the inlet air exceeds 70 %, a single evaporator mode is more effective for dehumidification. However, when the relative humidity is below 70 %, the dual evaporator mode is more advantageous, showing better heating performance.

Does the Novel Dual Source Heat Pump (DSHP) Out-Perform the Ideal DSHP? Experimentation Versus Simulation of DSHP Based Thermodynamic Irreversibility of the Throttle Valve

Purpose: The air-source heat pumps are associated with continuous frosting problems. To ensure a more energy efficiency technology, the novel dual-source heat pump (DSHP) was developed. This article aims to confirm and compare the energy performance of the novel dual-source heat pump (DSHP) with the performance of an ideal heat pump. Methods: We applied an experimental analysis from an installed DSHP system with converters and other components to obtain the energy performance of the DSHP, while the performance of an ideal pump was obtained from simulation based on the theoretical algorithm of the basic principle of the thermodynamic irreversibility of the throttle valve. Results: We found that the Ideal (simulated) DSHP has a higher coefficient of performance (COP) than the installed (experimented) DSHP. The Ideal DSHP’s COP of 4.52 is higher than the Novel DSHP’s COP, which range from 1.78 (day 3) to 2.01 (day 1). The DSHP are power efficient, which reduces carbon emission from whatever power source that is been used. Implications: Energy efficiency in buildings has severe implications for global warmings and the need for sustainability. Because the modern ventilation system utilise energy from waste and heat recovery to power heating and cooling systems, the DSHP remains promising for future generations of building ventilation design. Originality/Value: The value of the study is because it completes an experiment that analyse the performance of the DSHP, comparing the outcomes with results from a simulation based on an Ideal system.

Collaborative Fabrication of High-Quality Perovskite Films for Efficient Solar Modules through Solvent Engineering and Vacuum Flash System.

The vacuum flash solution method has gained widespread recognition in the preparation of perovskite thin films, laying the foundation for the industrialization of perovskite solar cells. However, the low volatility of dimethyl sulfoxide and its weak interaction with formamidine-based perovskites significantly hinder the preparation of cell modules and the further improvement of photovoltaic performance. In this study, we describe an efficient and reproducible method for preparing large-scale, highly uniform formamidinium lead triiodide (FAPbI3) perovskite films. This is achieved by accelerating the vacuum flash rate and leveraging the complex synergism. Specifically, we designed a dual pump system to accelerate the depressurization rate of the vacuum system and compared the quality of perovskite film formed at different depressurization rates. Further, to overcome the limitations posed by DMSO, we substituted N-methylpyrrolidone as the ligand solvent, creating a stable intermediate complex phase. After annealing, it can be transformed into a uniform and pinhole-free FAPbI3 film. Due to the superior quality of these films, the large area perovskite solar module achieved a power conversion efficiency of 22.7% with an active area of 21.4 cm2. Additionally, it obtained an official certified efficiency of 22.1% with an aperture area of 22 cm2, and it demonstrated long-term stability.

A novel methodology for map-based model fitting: A case study with a Dual Source Heat Pump experimental dataset

This paper presents a new methodology to adjust map-based models to experimental data and reports the main results of a comprehensive experimental campaign of a Dual Source Heat Pump (DSHP) prototype. The prototype tested incorporates variable speed components (compressor, circulation pumps, and fan). The novelty of this prototype lies in its ability to select two possible heat sources: air or ground. Thus, it can operate as a geothermal or aerothermal heat pump, as well as a chiller, thanks to the additional capacity to reverse the cycle. Thanks to this hybrid approach, several advantages can be obtained compared to conventional equipment, such as higher efficiency, the requirement of smaller borehole heat exchangers, or the absence of defrost cycles. In a prior study, polynomial models were developed to accurately characterize the DSHP’s performance (i.e., condenser and evaporator capacities and electrical energy consumption). These models were obtained considering the external variables to the unit as independent variables to facilitate their applicability using variables commonly measured in real installations. Due to the complexity of heat pump performance, which in current equipment can be influenced by up to 5 or 6 independent variables, the search for suitable polynomial models required the availability of a complete working map including more than 3000 working points. Thus, this previous work developed these models based only on simulation results. In this sense, this paper concludes the development of these models by focusing on two critical issues concerning empirical model development. The first aspect involves determining the minimum number and location of testing points needed to define the experimental sample for the model adjustment. The reported experimental data were obtained by analyzing the most suitable experimental design methodology to create the experimental matrices in each operating mode of the DSHP. The second aspect focuses on the final adjustment of models using experimental data. A novel fitting approach for empirical models is introduced in the last part of this study. The developed methodology enables the integration of simulation and experimental results for the final fitting of empirical models through a two-step adjustment. The first step involves analyzing and defining polynomial functionals from the complete working maps generated by simulation. Subsequently, in a second step, the polynomial models are refitted to a suitable experimental sample using the methodology presented in this work. The latter allows for the increase of the accuracy of the models and the minimization of experimental costs. This novel approach ensures a robust characterization of systems with many independent variables using a minimum amount of experimental data. Significant benefits can be obtained from its application, such as the reduction of experimental cost and an increase in the model’s accuracy through an effective combination of both experimental and simulated information. Furthermore, it can be considered of general applicability to other engineering problems where the characterization of physical systems influenced by a high number of independent variables is required.

Heat transfer process and anti-frost performance of finned evaporator with air–water dual heat source for building heat supply

ABSTRACT In this research, a dual heat source heat pump evaporator (AWSHP) with low-temperature hot water and air energy as the heat source is presented for the frosting problem of an air-source heat pump (ASHP) in low-temperature operating conditions. The critical frost region of the AWSHP system was also mapped using air temperature and water spray temperature as variables. The heat transfer characteristics as well as the anti-frost performance of AWSHP under different operating conditions were analyzed through experiments and simulations. According to the study's findings, the AWSHP system's refrigerant evaporation temperature was higher at the same ambient temperature than that of the ASHP. With AWSHP spray water volume of 8L/min and heat pump condenser circulating water volume of 15L/min, the average refrigerant heat exchanger and COP of AWSHP increased by 14.8% and 11.1%, respectively, compared with the ASHP system. At the same time, the AWSHP anti-frost operation strategy is proposed for low-temperature operating conditions. When the water spray volume was adjusted to 0.25 and 1.75 m³/h, respectively, under varying hourly meteorological conditions, the frost-free operation time was 61.21% and 89.24%, respectively. This was an improvement of 18.17% and 46.20%, respectively, compared to the ASHP.

Soliton synchronization in microresonators with a modulated pump.

Microresonator frequency comb generation from Kerr solitons has become a cutting edge technology, but challenges remain in creating, maintaining, and controlling the solitons. Pump modulation and dual pumping are promising techniques for meeting these challenges. Here we derive the equationof motion of solitons interacting with a modulated pump in the framework of synchronization theory. It implies that the soliton repetition rate locks to the modulation frequency whenever the latter is within a locking range of frequencies around an integer multiple of the free spectral range of the microresonator. We calculate explicitly, numerically, and in perturbation theory the width of the locking range as a function of the amplitude and frequency of the pump and the modulation phase. We show that a highly red-detuned, strong pump that is amplitude-modulated provides the best conditions for entrainment, and that the width of the locking range is proportional to the square of the modulation frequency, limiting the effectiveness of RF modulation as an entrainment method.

Characteristic study of valveless pump with dual outlet composite drainage structures

Abstract Valveless pumps are gaining importance in various fields. However, the reflux phenomenon can reduce pump performance and limit its application. This article proposes a dual outlet composite drainage structure valve-less piezoelectric pump with multiple semicircular arc structures within the flow channel to address this issue. The operating methods are explained, and the pump output flow rate formulation has been derived. The ANSYS CFX was used to simulate flow conditions in various directions. A prototype pump was then produced and tested using 3D printing technology. The results show that the flow rate gets a maximum state of 189.6 mL/min under a voltage of 200 V and a frequency of 50 Hz.

Allometric scaling of the parameters characterizing venous return surface in the generalized framework of circulatory equilibrium

Study objective: In the generalized framework of circulatory equilibrium (GCE), the integrated cardiac output (CO) curve characterizes the pumping abilities of the left and right hearts, whereas the venous return (VR) surface characterizes the preloading properties of the systemic and pulmonary circuits. Equilibrium CO (= VR), left (PLA) and right (PRA) atrial pressures are predicted from the intersection between the CO curve and VR surface. In VR surface, VR is theoretically related with stressed blood volume (V), PLA and PRA as: VR =V/W − Gs × PRA − Gp × PLA, where Gs and Gp is a ratio of systemic (Cs) and pulmonary (Cp) vascular compliance to W (time constant of the systemic and pulmonary circuits), respectively. However, there was a concern whether the standard parameters can be applicable to animals with different body size including human. The objective of this study is to experimentally investigate whether an allometric scaling of the parameters (Gs, Gp, W, Cs, Cp) of the VR surface is feasible. Hypothesis: Kleiber’s law indicates that an animal's metabolic rate scales to the 3⁄4 power of the animal's body weight (BW). Based on this, we hypothesize that Cs and Cp may be proportionate to BW, W may be proportionate to BW1/4. Hence, Gs and Gp may be proportionate to BW3/4. Methodology: Seven mongrel dogs (BW 26±2.8 kg) and 4 beagles (BW 9±0.5 kg) were anesthetized, and their left and right hearts were replaced by dual mechanical pumps. While V was kept constant, by controlling the speed of the fluid pumps, VR (ml/min), PLA and PRA (mmHg) were changed variably over a wide range to obtain six sets of VR, PLA and PRA. After the change of a known amount of V (4 mL/kg), six sets of VR, PLA and PRA were obtained in a similar manner. Using 12 sets of VR, PLA and PRA, we obtained Gs, Gp, W, Cs, and Cp using regression analysis in each animal. Finally, we analyzed relations between BW and all these parameters using regression analysis over the 11 animals. Data: Gs (r2=0.73, p value for independent variable piv<0.01; p value for intercept, pi=0.57) and Gp (r2=0.81, piv<0.01, pi=0.64) were proportionate to BW3/4. Cs (r2=0.37, piv=0.027, pi=0.40) and Cp (r2=0.61, piv<0.01, pi=0.48) were proportionate to BW. However, W (r2=-0.11, piv=0.90, pi=0.17) was not associated with BW1/4. Summary of results: All parameters characterizing VR surface except for W were significantly associated with BW. W did not show a significant association with BW, potentially due to the low variations of BW. Conclusions: Allometric scaling of VR surface may be feasible and effective in future clinical application of GCE. NTT Research, Inc. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Peak-power and width tunable noise-like pulses from a figure-9 cavity with two separate gain segments

A novel feature of noise-like pulses (NLPs) from a dual pump module based figure-9 cavity has been presented in this manuscript. The laser is mode-locked by taking advantage of a non-linear amplifying loop mirror (NALM) and the cavity contains a LOOP and an ARM, each section comprises an Yb-doped fiber pumped by an independently controllable pump module. In stable conditions, the laser delivers nanosecond rectangular pulses at a fundamental repetition rate of 1.96 MHz. The NLPs are recognized from their double-scaled auto-correlation trace. Akin to typical NLPs, the pulse duration increases with the pump power of the pump modules placed at the LOOP, whereas, it is noticed that the pulse width tends to reduce with the power of the pump module placed outside the LOOP, which is an unconventional behavior for NLPs. Alongside the pulse duration, the peak power also behaves oppositely with the pump power of individual modules. In the best operating condition, the maximum average power is 766 mW corresponding to 136 W peak power and pulse energy of 390 nJ. This study offers a possible direction to explore the dynamics of NLPs in laser cavities with two independent pump modules.

Dynamic performance forecast analysis of MHP-PV/T-IDXSAHP system during heating season

MHP-PV/T is a novel PV/T with phase change heat transfer, uniform flow of working medium and good anti-freeze performance. The excellent year-round performance of MHP-PV/T has been demonstrated in previous studies and is more suitable for winter heating in northern China. In this work, we further combine MHP-PV/T with dual source heat pump to form an experimentally validated indirect expansion-solar assisted heat pump (IDX-SAHP) system and simulates the overall performance of the heating system in winter based on TRNSYS in Lanzhou, China. The component type50b of TRNSYS was modified to make it closer to the actual results of MHP-PV/T. Research shown that the thermal efficiency of MHP-PV/T heat pump system can be maintained well throughout the heating season at the SAHP/ASHP switching temperature is 7 ℃ in winter. The net system energy efficiency ratio (NSEER) during heating season is range from 3.28 to 5.42, which can achieve highly efficient and low cost heating. For this system, the photovoltaic power generation is sufficient to meet the operation of three water pumps. By connecting surplus electricity to the grid, a total of 1806.25 ¥ of electricity revenue can be obtained around the year. The PEUR of the system is 72.26 %, the DPP taking 5.133 years, and the annual CO2 emission reduction is 13486.5 kg. Significant energy, economic, and environmental benefits of the system. This study demonstrates the application prospects of PV/T heat pumps and provides a reference basis for subsequent research on MHP-PV/T heat pump systems in cold regions.

Dual acid-pump blocking as novel therapeutic approach to treatment of acid-related diseases

Proton-pump inhibitors are highly efficient in the treatment of acid-related disease; however, their efficacy in treating reflux symptoms, healing esophageal erosions and peptic ulcers and eradicating Helicobacter pylori is sometimes suboptimal. Potassium-competitive acid blockers have a different mechanism of action, resulting in higher and longer-lasting increases in intragastric pH, which is neither non-inferior or superior to those of proton-pump inhibitors. The pharmacology, metabolism and mechanism of action of these drugs are different, therefore, it is hypothesised, that their combined use might be of clinical benefit through increased intragastric pH. This hypothesis is supported by pharmacological, physiological and microbiological data. The combined administration of proton-pump inhibitors and potassium-competitive acid blockers should be investigated in short-term therapy (4–8 weeks); if their complementary or additive effect is proven, dual acid pump blocking can be of further benefit in managing gastroesophageal reflux disease, peptic ulcers and eradicating Helicobacter pylori infection, in cases refractory to current therapies. For safety reasons, long-term administration of this combination as maintenance treatment should be avoided.

Dissipative Kerr soliton generation at 2μm in a silicon nitride microresonator

Chip-scale optical frequency combs enable the generation of highly-coherent pulsed light at gigahertz-level repetition rates, with potential technological impact ranging from telecommunications to sensing and spectroscopy. In combination with techniques such as dual-comb spectroscopy, their utilization would be particularly beneficial for sensing of molecular species in the mid-infrared spectrum, in an integrated fashion. However, few demonstrations of direct microcomb generation within this spectral region have been showcased so far. In this work, we report the generation of Kerr soliton microcombs in silicon nitride integrated photonics. Leveraging a high-Q silicon nitride microresonator, our device achieves soliton generation under milliwatt-level pumping at 1.97 µm, with a generated spectrum encompassing a 422 nm bandwidth and extending up to 2.25 µm. The use of a dual pumping scheme allows reliable access to several comb states, including primary combs, modulation instability combs, as well as multi- and single-soliton states, the latter exhibiting high stability and low phase noise. Our work extends the domain of silicon nitride based Kerr microcombs towards the mid-infrared using accessible factory-grade technology and lays the foundations for the realization of fully integrated mid-infrared comb sources.

Performance analysis on the heating performance of CPV/T-air dual source heat pump system with finned microchannels heat exchanger

Solar-assisted heat pump technology is a clean building energy conserving technique with high efficiency, but it often has limitations such as large evaporator cover area and significant susceptibility to weather conditions, preventing it from being widely used. In this paper, a concentrated photovoltaic/thermal-air dual source heat pump system integrated with finned microchannel heat exchanger (CPV/T-FMC-SAHP) is proposed to solve these problems. A mathematical model for the CPV/T-FMC-SAHP system is developed, and sensitivity analysis of different environmental parameters on system performance is conducted by numerical simulation. Performance comparisons are made under dual-source and solar heating modes to explore the optimal operating conditions. The results suggest that changes in ambient temperature have a relatively minor impact, primarily attributed to the limited surface area of the evaporator. On the other hand, increased irradiance, facilitated by the concentrator, significantly improves the system's performance. In the case of solar irradiation at 600 W/m2 and an ambient temperature of 13 °C, the system's heating capacity is 1747.38 W, with a COP reaching 5.31. In comparison, the COP of existing solar-assisted heat pump systems under this condition are about 4.5, so there is an improvement of about 18 %. Furthermore, activating the air blower on the weather with bad irradiation but relatively warm can further increase the system's heating capacity. To sum up, the CPV/T-FMC-SAHP system exhibits a substantial improvement in performance and high level of integration compared to traditional solar-assisted heat pumps. Therefore, this system can provide ideas for improving the performance of heat pumps in the case of limited space. It is not only meaningful in the field of building energy conserving, but also conducive to addressing global energy challenges.

Effective multiband synthetic four-wave mixing by cascading quadratic processes

Four-wave mixing (FWM) is an important technique for supercontinuum and frequency comb generation in the mid-infrared band. Here, we report simultaneous synthetic FWM in both the visible and mid-infrared bands by cascading quadratic nonlinear processes in a periodically poled lithium niobate (PPLN) crystal, which has a conversion efficiency that is 110 dB (at 3000 nm) higher than the FWM generated directly using third-order susceptibilities in bulk PPLN crystals. A general model of the proposed process is developed that shows full agreement with the experimental verification results. The frequency difference between the emerging frequency components can be tuned freely by varying the frequency difference between the dual pump lasers. Furthermore, by increasing the conversion bandwidth and the efficiency of the cascaded processes, it becomes feasible to generate frequency combs simultaneously in three bands, comprising the visible, near-infrared, and mid-infrared bands, via high-order cascaded processes. This work represents a route toward free-tuning multiband frequency comb generation with multi-octave frequency spanning that will have significant applications in fields, including mid-infrared gas sensing, lidar, and high-precision spectroscopy.

CO2 capture using gas-lift pumps operating under two-phase flow conditions

CO2 capture through dissolution in water offers environmental benefits and industry applications. However, current studies mostly focus on CO2 extraction into solvents, overlooking its direct solubility in water. Alternatively, gas-lift pumps may hold significant potential for capturing and storing CO2 in water; but this ability remains unexplored. Therefore, this study experimentally delves into the CO2 capture capacity and hydraulic performance of a dual injection gas-lift pump with a 25.4 mm riser diameter. Operating at a constant submergence ratio of 70 %, the pump is fed with simulated flue gas with flow rates within 5–30 LPM at volumetric CO2 concentrations of 10 %, 15 %, and 25 %, and temperatures of 22 °C (isothermal operation) and 110 °C (non-isothermal operation). Two-phase flow hydrodynamics is also evaluated using high-speed imaging in conjunction with time-series void fraction measurements. Within the riser pipe, three distinct two-phase flow patterns — slug, intermittent, and churn flows — are identified. The results reveal that under both isothermal and non-isothermal operations and across all volumetric CO2 concentration levels, churn flow demonstrates superior mass transfer coefficient and lifted liquid flow rate, while slug flow achieves minimum energy consumption per ton of captured CO2, highest CO2 capture degree, and maximum lifting efficiency. Also, the highest degrees of sensitivity to inlet gas flow rate for volumetric mass transfer coefficient, delivered liquid flow rate, and void fraction were observed in slug flow regime. Both gas temperature and volumetric CO2 concentration positively impacted the mass transfer performance. However, the pump showed remarkably higher lifting efficiencies under isothermal operation conditions. Moreover, compared to four established CO2 capture methods (absorption, adsorption, cryogenic distillation, and membrane diffusion), the gas-lift pump exhibits moderately lower energy consumption, at 38-266 kWh/tonCO2, but with lower CO2 capture degree of 2.3 % to 6.7 %.

Dual feed progressive cavity pump extrusion system for functionally graded direct ink write 3D printing

Material extrusion Additive Manufacturing (AM), is one of the most widely practiced methods of AM. Fused Filament Fabrication (FFF) is what most associate with AM, as it is relatively inexpensive, and highly accessible, involving feeding plastic filament into a hot-end that melts and extrudes from a nozzle as the toolhead moves along the toolpath. Direct Ink Write (DIW) 3D printing falls into this same category of AM, however is primarily practiced in laboratory settings to construct novel parts from flowable feedstock materials. DIW printers are relatively expensive and often depend on custom software to print a part, limiting user-specificity. There have been recent advancements in multi-material and functionally graded DIW, but the systems are highly custom and the methods used to achieve multi-material prints are openly available to the public. The following article outlines the construction and operation method of a DIW system that is capable of printing that can produce compositionally-graded components using a dual feed progressive cavity pump extruder equipped with a dynamic mixer. The extruder and its capabilities to vary material composition while printing are demonstrated using a Prusa i3 MK3S+ desktop fused filament fabrication printer as the gantry system. This provides users ease of operation, and the capability of further tailoring to specific needs.

Thermal and fluid aspects of dual piezoelectric jet pump of double chambers

The rapid development of electronics has led to a significant reduction in the size of electronic devices, while increasing their power consumption. This has resulted in the need for small-scale thermal management solutions. Piezoelectric pump is one of the efficient devices for local thermal management. This paper presents a novel configuration of a piezoelectric pump, which separates the pump chamber with a rigid wall to create two independent pulsating flows. This configuration aims to reduce eddies within each chamber. Furthermore, the proposed design incorporates two pairs of open-sided channels to guide the pulsating flow towards the hot target. The electrostatics physic of the piezoelectric patches along with energy and momentum equations in three dimensions are manipulating mathematically and solved numerically using the finite element method (FEM) and the Arbitrary Lagrangian-Eulerian (ALE) technique. The implicit Large Eddy Simulation (iLES) turbulence model is adopted for this purpose. Several parameters, including frequency, voltage, and the radius of the piezoelectric patch are investigated to better understanding their influence on both the zero-net volumetric flow rate and the heat transfer process. The findings indicate that by separating the pump chamber, it becomes feasible to obtain a 3D solution with the iLES using a reasonable mesh size. Nusselt number increases with all the examined parameters, where it enhances by 42.48 % at V = 100 Volt when the pump is switched on compared to natural convection mode. The peak-peak volumetric flowrates rises by 50 % and 350 % when the applied voltage is raised from 50 to 100 Volts and the frequency is raised from 20 to 50.50 kHz, respectively.

Novel closed-loop control system of dual rotary blood pumps in total artificial heart based on the circulatory equilibrium framework: a proof-of-concept in vivo study.

Total artificial heart (TAH) using dual rotary blood pumps (RBPs) is a potential treatment for end-stage heart failure. A well-noted challenge with RBPs is their low sensitivity to preload, which can lead to venous congestion and ventricular suction. To address this issue, we have developed an innovative closed-loop control system of dual RBPs in TAH. This system emulates the Frank-Starling law of the heart in controlling RBPs while monitoring stressed blood volume (V) based on the circulatory equilibrium framework. We validated the system in in-vivo experiments. In 9 anesthetized dogs, we prepared a TAH circuit using 2 centrifugal-type RBPs. We first investigated whether the flow and inlet atrial pressure in each RBP adhered to a logarithmic Frank-Starling curve. We then examined whether the RBP flows and atrial pressures were maintained stably during aortic occlusion (AO) and pulmonary cannula stenosis (PS), whether averaged flow of dual RBPs and bilateral atrial pressures were controlled to their predefined target values for a specific V, and whether this system could maintain the atrial pressures within predefined control ranges under significant changes in V. This system effectively emulated the logarithmic Frank-Starling curve. It robustly stabilized the flow and atrial pressures during AO and PS without venous congestion or ventricular suction, accurately achieved target values in averaged flow and atrial pressures, and efficaciously maintained these pressures within the control ranges. This system controls dual RBPs in TAH accurately and stably. This system may accelerate clinical application of TAH with dual RBPs.

Label-free high-throughput impedance-activated cell sorting.

Cell sorting holds broad applications in fields such as early cancer diagnosis, cell differentiation studies, drug screening, and single-cell sequencing. However, achieving high-throughput and high-purity in label-free single-cell sorting is challenging. To overcome this issue, we propose a label-free, high-throughput, and high-accuracy impedance-activated cell sorting system based on impedance detection and dual membrane pumps. Leveraging the low-latency characteristics of FPGA, the system facilitates real-time dual-frequency single-cell impedance detection with high-throughput (5 × 104 cells per s) for HeLa, MDA-MB-231, and Jurkat cells. Furthermore, the system accomplishes low-latency (less than 0.3 ms), label-free, high-throughput (1000 particles per s) and high-accuracy (almost 99%) single-particle sorting using FPGA-based high-precision sort-timing prediction. In experiments with Jurkat and MDA-MB-231 cells, the system achieved a throughput of up to 1000 cells per s, maintaining a pre-sorting purity of 28.57% and increasing post-sorting purity to 97.09%. These findings indicate that our system holds significant potential for applications in label-free, high-throughput cell sorting.

Is waste heat recovery a promising avenue for the Carnot battery? Techno-economic optimisation of an electric booster-assisted Carnot battery integrated into different data centres

The transition to intermittent renewable energies will necessitate the integration of storage. An interesting technology is the Carnot battery (CB), a novel power-to-heat-to-power system, capable of harnessing waste energy streams. While initial studies have indicated that, under ideal conditions, CB can be competitive with conventional technologies such as chemical batteries, their economic viability in real-world applications remains uncertain. To fill this gap, this work explores the techno-economic potential of electric booster-assisted CB integrated within data centres. Motivation for this case study is the recovery of waste heat, leading to an improved electrical storage efficiency. To maximise the energy self-sufficiency and the internal rate of return, we have applied multi-criteria optimisation to the system design, under three different thermal integration scenarios and for two sets of climatic conditions, using a thermodynamic model and time series from a real data centre. Our analyses suggest that current projections for electricity prices and CB costs yield payback periods exceeding a decade, but that these could fall below ten years if the CB capital costs were halved. Furthermore, it turns out that the choice of optimum charging system (i.e. right balance between heat pump and electrical heater) is contingent on the heat source temperature and availability. For higher temperatures (e.g. 60 °C), heat pumps emerge as the financially most attractive option, thanks to their superior coefficient of performance, whereas for lower temperatures (< 25 °C), resistive heaters are preferable. Results also show that when the aim is to increase the energy self-sufficiency, there exist an efficiency/charging capacity trade-off, which causes a dilemma for the system design. On the one hand, heat pumps are vital to increase the efficiency of the CB, but on the other hand, as the amount of thermal energy available at its source is limited by the data centre operations, electrical boosters are indispensable to increase the charging capacity. To soften this dilemma and enhance the techno-economic performance of thermally integrated CB, future research should explore more efficient booster configurations, such as dual heat source heat pumps.