Single Pump System Research Articles

Load prediction and energy efficiency improvement of steelmaking waste heat centralized heating systems under mild climate in China

HVAC energy consumption accounts for more than 50 % of the total building energy consumption globally and using industrial waste heat has huge potential for energy savings in central heating systems. Under the background of the use of renewable energy and the gradual rise of central heating in mild climate areas in China, it is worth paying attention to the problem of excessive energy consumption caused by the inaccurate load prediction of central heating systems when the ambient temperature changes. L City, Guizhou Province, is the first city with central heating in southern China. The temperature variation during winter in L City can manifest the climatic characteristics of a mild region. Therefore, based on the operational data of the steel waste heat central heating system in L City, Guizhou Province, China, during the heating season of 2022–2023, this study discusses the load prediction and energy-saving optimization strategy of the central heating system in a mild climate. SketchUp was used to conduct 3D modeling of the actual buildings in the heating area and TRNSYS was imported to simulate the system load. The difference between the heating load forecast and the actual operating data was analyzed in detail by using the calculation results. Based on the simulation results, the waste heat utilization strategy was adjusted and the influence of different heating schemes on the pump energy consumption under different load demands was discussed. The results reveal that based on the temperature change rule, the accurate load prediction can lead to a 28.64 % saving of the system energy. Concerning system energy consumption, by adjusting the water flow and choosing the large and small pump system, the energy saving amounts to 39.48 % compared with the traditional single-pump system. Meanwhile, in the transition season when the heating demand is less than 20 MW, the adjusted heating scheme can achieve a 38.5 % saving based on the constant flow scheme and a 5.4 % saving based on the constant temperature difference scheme. This article provides a scientific energy-saving solution for heating in mild climates using industrial waste heat, not only reducing energy consumption but also providing an important reference for the energy-saving renovation of heating systems in similar areas.

Improving energy efficiency of individual centrifugal pump systems using model-free and on-line optimization methods

Pump systems around the world account for a high percentage of electrical energy consumption. The energy efficiency of these systems can be improved using control algorithms to determine appropriate operating points. The problem that arises is that computed operating points deviate from real operating points. This is due to deviations of the affinity laws, inaccurate information about pump characteristics, and plant behavior. In order to address this problem, we will present model-free optimization methods that can optimize various pump systems during ongoing operation. First, we will classify different pump systems. Based on this categorization, we will then analyze characteristic systems with regard to their energetic optimum. The resulting findings will enable us to identify suitable optimization algorithms. These model-free optimization algorithms take the form of an extremum seeking control in combination with a Kalman filter, the Nelder Mead algorithm, and a dynamic optimization method. After describing these algorithms, we will optimize and validate three sample classes of pump systems using the respective appropriate optimization strategy. The three classes represent a single-pump system, a multiple parallel pump system and a pump storage system. We can see that all optimization strategies achieve the energetic optimum. We can identify savings of between 7.9% and 50%, depending on the system in question. Finally, we will present a best-fit model-free optimization strategy for each class, and system operators can employ this strategy to ensure energy-optimized operation of their specific system.

Energy Consumption Comparison of a Single Variable-Speed Pump and a System of Two Pumps: Variable-Speed and Fixed-Speed

The energy efficiency of a multi-pump system consisting of two low-power (0.75 kW) pumps operating in parallel mode and a single-pump mechanism (1.5 kW) is compared in this study. For this purpose, mathematical models, experimental data, and data retrieved from the manuals provided by the pump manufacturers are used. The single-pump system is fed by a single variable speed drive. A multi-pump system running in parallel mode consists of two pumps. One of them is driven by an induction motor connected directly to the electrical grid and equipped with a throttle. Another pump is actuated by an induction motor fed by a variable speed drive. The flowrate of the liquid in the multi-pump is controlled with the help of speed variation and throttling. In the case of the single-pump system the conventional speed control method is applied during the analysis. For both pump system topologies, the daily and annual energy consumption is obtained. As a result of conducted calculations, it was shown that the multi-pump provides 29.8% savings in comparison to the single-pump system in the case of a typical flowrate profile.

Primary Step Towards In Situ Detection of Chemical Biomarkers in the UNIVERSE via Liquid-Based Analytical System: Development of an Automated Online Trapping/Liquid Chromatography System.

The search for biomarkers in our solar system is a fundamental challenge for the space research community. It encompasses major difficulties linked to their very low concentration levels, their ambiguous origins (biotic or abiotic), as well as their diversity and complexity. Even if, in 40 years’ time, great improvements in sample pre-treatment, chromatographic separation and mass spectrometry detection have been achieved, there is still a need for new in situ scientific instrumentation. This work presents an original liquid chromatographic system with a trapping unit dedicated to the one-pot detection of a large set of non-volatile extra-terrestrial compounds. It is composed of two units, monitored by a single pump. The first unit is an online trapping unit able to trap polar, apolar, monomeric and polymeric organics. The second unit is an online analytical unit with a high-resolution Q-Orbitrap mass spectrometer. The designed single pump system was as efficient as a laboratory dual-trap LC system for the analysis of amino acids, nucleobases and oligopeptides. The overall setup significantly improves sensitivity, providing limits of detection ranging from ppb to ppt levels, thus meeting with in situ enquiries.

Power conversion optimization for hydraulic systems controlled by variable speed drives

Pumps are widely used in various domestic and industrial applications, such as in water and waste water, food and beverage, and oil and gas applications. In most cases, a pump is controlled by an asynchronous motor which converts the electrical power into the mechanical power required for the pump operation. The motor can be either connected directly to the mains (DOL) or controlled by a variable speed drive (VSD). The energy management of a global pumping system becomes very important to reduce the energy cost of the installations and optimize the maintenance cost, for instance, by increasing the lifetime of the equipment. A VSD is essential to increase the energy efficiency of the overall pump system. A VSD allows delivering all possible mechanical working points (speed, torque), and consequently, only the mechanical power required by the system. Furthermore, a VSD plays an important role in optimizing the electrical energy consumed by the motor as a function of the mechanical energy provided to the pump. This is achieved by minimizing the electrical heat energy losses. In this paper, we propose an original method for electrical energy optimization for a complete pump system including a motor and drive. The objective is to determine the optimal pump speed that minimizes the electrical energy consumption for a hydraulic operating system point. We model the system including a VSD, a motor, a pump, and the hydraulic application. Subsequently, we define the process optimization problem for a single pump and multiple pumps systems. For the single pump system, we demonstrate that the solution of the optimization problem is equivalent to minimization of the drive and motor losses. For the multiple pumps system, we show that we must also optimize the pump losses. For the hydraulic system using multiple pumps, the process demand is actually shared between these pumps. Thus, the speed of each pump is set such that the total energy consumption of the global pumping system is optimized. The simulation and experimental results exhibit the relevance of this power optimization approach for hydraulic pumping systems.

A microfluidic manifold with a single pump system to generate highly mono-disperse alginate beads for cell encapsulation.

Cell encapsulation technology is a promising strategy applicable to tissue engineering and cell therapy. Many advanced microencapsulation chips that function via multiple syringe pumps have been developed to generate mono-disperse hydrogel beads encapsulating cells. However, their operation is difficult and only trained microfluidic engineers can use them with dexterity. Hence, we propose a microfluidic manifold system, driven by a single syringe pump, which can enable the setup of automated flow sequences and generate highly mono-disperse alginate beads by minimizing disturbances to the pump pressure. The encapsulation of P19 mouse embryonic carcinoma cells and embryonic body formation are demonstrated to prove the efficiency of the proposed system.

Determination of trace inorganic anions in anionic surfactants by single-pump column-switching ion chromatography

Abstract An ion chromatography method has been proposed for the determination of three common inorganic anions (chloride, nitrate and sulfate) in anionic surfactants using a single pump system. The new system consists of an ion exclusion column, a concentrator column, and an anion exchange column connected in series via two 6-ports valves in a Dionex ICS-2000 ion chromatograph. The valves were switched several times for removing surfactants, concentrating and separating the three anions. The chromatographic conditions were optimized. Detection limits (S/N = 3) were in the range of 0.10–0.68 μg/L. The relative standard deviations (RSDs) of peak area were less than 4.6%. The recoveries were in the range of 84.1–112.6%.

Development of a New Pulsatile Extracorporeal Life Support Device Incorporating a Dual Pulsatile Blood Pump

A new pulsatile extracorporeal life support device (ECLS) has been developed, designed to sustain pulsatile blood flow during emergency cardiopulmonary resuscitations and cardiopulmonary operations. This device features two identical pulsatile pumps that operate alternately and can therefore provide blood inflow in a more uniform manner than similar systems featuring a single-pump configuration. In order to confirm the presumed benefits of this newly-developed dual pulsatile pump configuration, we have conducted a series of in vitro experiments designed to compare the properties of the new system with a single pump system, specifically with regard to pump delivery rate and active filling efficiency. Our results reveal that the dual pump configuration can, indeed, deliver a higher flow than can the single-pump system, and exhibits an active filling efficiency superior to that of the single-pump configuration. We performed a series of animal experiments to measure the pulsatility of the dual-pump configuration in terms of equivalent energy pressure (EEP). In order to measure EEP, we measured femoral arterial pressure and pump outflow. The results of our animal experiments revealed that the newly-developed pulstile ECLS exhibits sufficient pulsatility in terms of the EEP considerations.

Development of a compact supersonic jet/multiphoton ionization/time-of-flight mass spectrometer for the on-site analysis of dioxin, part II: Application to chlorobenzene and dibenzofuran.

A compact supersonic jet/multiphoton ionization/mass spectrometer (SSJ/MPI/MS) equipped with a single pump system was developed for use in the analysis of dioxin. A mass spectrum and multiphoton ionization spectrum were obtained for chlorobenzene and dibenzofuran using an optical parametric oscillator (OPO) for excitation and subsequent ionization. The detection limit for chlorobenzene (S/N = 3) was 0.3 ppb, which corresponds to an absolute amount of 0.1 pg. The rotational temperature was 35 K. This slightly high temperature can be attributed to the long nozzle throat used in the instrument.

Piezoelectrically driven micropump for on-demand fuel-drop generation in an automobile heater with continuously adjustable power output

This paper describes a piezo-driven micropump for fuel dosing in automobile heaters with 5 kW peak power output. The micropump has been developed in a joint effort of the Lehrstuhl für Feingerätebau und Mikrotechnik and the Lehrstuhl A für Thermodynamik, both of the Technische Universität München; it is capable of generating a freely controllable flow of microscopic fuel drops in air. The operating principle, derived from piezoelectric printing systems, lends itself to building a micro membrane pump by dedicated microtechnologies. This micropurnp generates very small but reproducible fuel drops ejected through a multitude of nozzles into a neighbouring combustion chamber, where they are vaporized and burnt. The ejection velocity of the drops can be varied in the range 4 to 7 m s -1 and mass flow can be controlled by adjusting the drop ejection frequency. Our micropump is characterized by a simple design for cost-effective mass production. A nozzle chamber manufactured by laser ablation and a piezo membrane are joined to yield a working pump. A single-pump system can generate a heater power output of roughly 500 W. Regarding the performance data of the prototypes presented, a very promising fuel-dosing device can be expected for the near future.

Bivcutricular and respiratory support utilizing single pump system

Bivcutricular and respiratory support utilizing single pump system

A high-vacuum multichamber tester for specimens and materials

Working principles are described for a high-vacuum multichamber tester that provides four simultaneously operating vacuum chambers in which various thermal operations can be performed: annealing, life test with thermal stabilization, thermal cycling, effects of temperature and residual gases on the corrosion and physical properties of constructional materials, etc. Ongoing observations can be made on the specimen resistance. A feature is that there is a buffer vessel, i.e., a source of high oil-free vacuum, which enables one to maintain a different pressure in each of the chambers with a single pumping system.

Fluorimetric determination of indomethacin in human serum by high-performance liquid chromatography coupled with post-column photochemical reaction with hydrogen peroxide

A high-performance liquid chromatographic method involving post-column photochemical reaction and fluorimetric detection has been developed for the determination of indomethacin in serum. The bioanalytical set-up consisted of single-pump system for post-column photochemical reaction. The mobile phase consisted of 0.07 M phosphate buffer (pH 6.6)-acetonitrile (65:35, v/v) containing 180 m M hydrogen peroxide. The column effluent was irradiated with UV light to give fluorescence. The fluorimetric detection was monitored with excitation at 358 nm and emission at 462 nm. The calibration curve was linear over the range 0.05–30 μg/ml by injecting a volume of 10 μl of indomethacin solution. The detection limit (signal-to-noise ratio = 5) for indomethacin was 10 ng/ml using a 100-μl aliquot of deproteinized serum. The mean recovery from serum was 94.3%.

Kinetics of active sodium transport in rat proximal tubules and its variation by cardiac glycosides at zero net volume and ion fluxes. Evidence for a multisite sodium transport system.

1. Transepithelial Na concentration difference, deltaCNa, across proximal tubules of rat kidney was measured at varying intraluminal Na concentrations (CNainfinity) under conditions of zero net volume and Na flux. Simultaneous stopped-flow intratubular and artificial peritubular capillary perfusion techniques were used together with intratubular raffinose to achieve zero net fluxes. Under these conditions in rat proximal tubules, deltaCNa represents active transport, JactNa, factored by permeability, PNa, plus an electrical factor depending on transepithelial potential difference. 2. The relationship between CNainfinity and deltaCNa appeared sigmoidal with saturation being reached when intratubular Na was above 80 m-mole/kg. In the presence of ouabain (10(-2)M) and scilliroside (10(-3)M) the relationship remained the same. The maximum deltaCNa was reduced by approximately 50% by cardiac glycoside inhibition whereas the half-saturation constant was essentially unchanged. These changes from the control represent simple non-competitive inhibition by the cardiac glycosides. 3. Absence of potential difference (p.d.) measurements precludes exact description of the relation between true active transport and substrate concentration but much evidence indicates that the apparently sigmoid relation in the presence and absence of cardiac glycoside inhibition, would be retained if correction of deltaCNa values were possible. Such results could then be explained if there are at least three or more sites for Na on the pump system, of which at least two are not cardiac glycoside sensitive. They would also unequivocally exclude the presence of a single-site single-pump system or the simple algebraic addition of two such units since the kinetic curves for both would be hyperbolic rather than sigmoidal.

Total heart replacement by a single intrathoracic blood pump

Summary Initial trials of total heart replacement by a single artificial ventricle appear promising. Cardiac replacement by single ventricle is made possible by the use of a biologic circulatory shunt (i.e., superior vena cava-pulmonary artery anastomosis) and by draining the renal and hepatic veins directly into the left atrium. Eight experiments have been performed to evaluate this single pump system. These studies indicate that adequate arterial oxygenation and blood flow exist with these circulatory modifications. The longest experiment lasted 7 hours, 15 minutes. In that experiment, the dog's chest was closed and the animal was able to breathe spontaneously with respiratory assist. Bleeding has been the major postoperative problem. The single pump system has several advantages over previously described artificial hearts utilizing two blood pumps. These advantages are smaller size, greater reliability, fewer valves, lower energy requirement and a decreased hemolysis rate.