In this paper, a novel structure of electromagnetic pump to efficiently drive metal fluid was proposed, which can be called layered stack electromagnetic pump. Firstly, the coupled interaction mechanism of multi-physics fields was numerically interpreted, and the parameter optimizations of DC-EMP were systemically conducted. The optimization results show that inserting insulation bars can significantly

The organic Rankine cycle (ORC) is a promising method of recovering the exhaust heat of the internal combustion engine (ICE). However, the off-design exhaust conditions and the negative effects (such as increased backpressure and added weight) of the ORC installation onto vehicles greatly deteriorate the performance of ORC applied on mobile vehicles. In this paper, the ORC thermodynamic model with

This paper reports on experiments aiming to understand and to characterize how the working fluid spreads in an organic Rankine cycle (ORC) power system. To this end, a 2-kWe ORC test rig is constructed and tested over a wide range of conditions. Besides standard thermo-hydraulic sensors, the fluid charge distribution is measured on-line by bending load cells and infrared imaging techniques. Following

The effect of thermally-insulating layer, particularly oxide layer as found in metallurgical applications, on the water spray-cooling process was discussed. Such layers have been found to increase the quenching temperature at which the sprayed liquid begins to contact the hot surface, greatly increasing the cooling rate. The conventional, thermal-resistance based model can predict the shift of the

The cooling performance of a fan and pad system applied in a subtropical desert greenhouse (in Ahvaz-Iran) was evaluated during the critical climatic period from May to October using validated Computational Fluid Dynamics (CFD) method. The boundary and initial conditions of the models were set based on regional meteorological reports. Pad was separately simulated inside a wind tunnel and the porous

This article reviews the state of the art of chemisorption heat pumps that use ammonia as the refrigerant for cold-climate heating applications. In such a system, ammonia vapor is adsorbed by the solid salt through reversible chemisorption reactions, and the thermal effect of the reaction and ammonia phase change is used to extract heat from a cold environment and supply heat to a warm environment

The startup, operation and dry-out characteristics of pulsating heat pipes (PHPs) are influenced by many parameters, and researches on improving its performance by optimizing the parameters, especially the thermal-physical properties of working fluids, have drawn wide attention. In this paper, the effects of deionized water (DI water) and the surfactant solution on the startup, operation and dry-out

The stepped pressure cycle has been proven high energy-saving potentials in refrigeration and heat pump applications. However, recently we found that the conclusion of energy-saving is conditional on the evaporator superheat. To in-depth understand the effect of evaporator superheat on stepped pressure cycle performance, we did investigation by using the analytic method, numerical analysis and lab

A novel high performance refrigerant-air heat exchanger employing multiport extruded tubes which have parallel refrigerant mini-channels has recently been developed for heat pump systems. In evaporators, the inequality in heat loads among parallel refrigerant channels causes also inequalities in flow rates of refrigerant. This flow maldistribution induced by unequal heating not only makes it difficult

The oil exploit in late-period oilfield usually produce large amount of oily wastewater at moderate and high temperature, the thermal energy of which can be recuperated through a sewage source heat pump (SSHP). Among different kinds of heat recovery facility in SSHP, the spray heat exchanger is a better choice to recover energy from the oily wastewater due to its advantages of simple structure, high

In order to realize large-area and high-temperature plate heat dissipation in a restricted space, an innovative vectoring spray cooling device based on a novel synthetic jet actuator is proposed. Depending on the different response characteristics of different piezoelectric diaphragms to the same electric signals, this device doesn't need transmission or rotating parts, but is able to change its spray

In this study, the thermal impact of using annular porous fins attached to the outer surface of a suspended heated vertical cylinder with constant heat flux was experimentally investigated. The study took place under steady-state and natural convection conditions. Three diameters of Aluminum cylinders and two types of porous material were used with different fin configurations like fin thickness and

In order to investigate the effect of different states of charge (SOC) on air transport safety of lithium-ion batteries, 18650 lithium-ion batteries were used to conduct UN38.3 experiments of single-cell batteries and thermal runaway experiments of single-cell batteries and battery packages (multi-cell batteries). In the UN38.3 experiments of single-cell batteries, six tests were conducted, including

To improve the efficiency of heat exchanger systems for the purpose of reducing the size of the equipment and saving energy, the thermo-hydraulic performance of Fe3O4-water-arabic gum (AG) nanofluids in an improved heat exchange system is explored experimentally in this study. In the heat exchange system in these experiments, a corrugated tube is used instead of a smooth tube, a perforated turbulator

While designing and optimizing a concentrating solar central tower, it is crucial to obtain the accurate solar flux distribution and optical efficiency for a given heliostat field. Here we present a new model describing solar flux distribution on the surface of an external receiver, based on ray-tracing and a convolution algorithm. The receiver is located at the top of a center tower surrounded by

Before the phase change of ice on the aircraft surface occurs during an electrothermal de-icing process, the stresses developed in impact ice may have certain influence on the shedding of ice. To effectively improve the control accuracy of inflight de-icing, a numerical study on the thermo-mechanical coupling effect caused by aerodynamic force and electric heating is carried out. Based on the fundamental

This research work presents a numerical chamber model of a two-phase twin-screw expander and its further integration in a one-dimensional model of a Trilateral Flash Cycle (TFC) system for low-grade heat to power conversion applications. The novel feature of the expander is the capability of changing the built-in volume ratio (BIVR) of the machine through a sliding valve in the casing that opens an

Experimental investigations were conducted into the heat transfer characteristics of supercritical water in a downward flowing cooling tube surrounded by pool boiling for the passive cooling system of the Generation-IV Supercritical-Water-Cooled Reactor (SCWR). The experimental parameters cover the extreme high ranges of pressure (23–27 MPa), mass flux (600–1000 kg·m-2·s-1), bulk fluid temperature

Recently, membrane-based vacuum air dehumidification (MVD) systems have been studied as an advanced cooling scheme. In general, the working principle of these systems is based on the separation of water vapor from air caused by a vapor pressure gradient between the feed and permeate side of a membrane when humid air passes over the membrane. After permeating, the vapor is discharged to the atmosphere

In the present work, a new fin shape is proposed to improve the convective heat transfer in heat sinks and to reduce their weight. The problem under consideration is a natural convection problem with air as the working fluid . Three-dimensional numerical simulations are carried out using FLUENT 19.0, to solve the continuity, momentum, turbulence, and energy equations to predict the flow and temperature

The consumption of electrical and thermal energies in the residential building sector is growing fast and many strategies are being followed to overcome the energy demand in this sector. Among the various strategies, performance enhancement of refrigeration systems has been identified as one of the important areas for investigation. Due to the increase in the use of small-scale appliances and their

The combustion of by-products in boilers for steam generation plays an important role for heat recovery in industrial plants. However, the use of different fuels at the same time may cause flame imbalance, flame impingement and overheating at some points of the furnace. A numerical study of the reactive flow within a tangential fired boiler, to investigate the phenomenon of overheating in the furnace

With decreasing underground resources and increasing carbon dioxide levels, human beings are forced to use renewable energies and new methods for power generation and CO2 elimination. In this paper, an integrated structure is developed for generating power and liquefying CO2 using parabolic solar collectors, solid oxide fuel cell, CO2 power generation cycle, separation unit, and CO2 liquefaction. This

The ejector refrigeration cycle (ERC) is often used as the sub-cycle of power and cooling cogeneration systems due to its advantages of simple structure design, few moving parts, less system investment, good stability and reliable operation. Considering the potential of organic Rankine cycle (ORC) in the utilization of low-grade heat, and the advantages of simple structure and many choices for working

In this work, thermal transport process of open-cell metal foam/paraffin composite (MFPC) with solid-liquid phase change is experimentally investigated. The benchmark data including planar visualized phase and temperature fields of MFPC as well as temperature variations at critical inner positions are obtained by using photography and infrared technique together with thermocouples, respectively. The

In this study, a numerical analysis is used to compare the effects of uniform and cascaded graphite foams on the charge-discharge cycle performance of thermal energy storage systems where a phase change material (PCM) with a phase change temperature of 855K is used as the storage media. Firstly, for a constant PCM mass, the insertion of single graphite foams with respective porosities of 80%, 85%,

During heat waves, spraying heat exchanger helps to prevent overheating thermal processes like air conditioning systems. Spraying efficiency is studied to get the best performance enhancement ratio and avoid pressure drop related to water films. In this paper, we studied the effectiveness and local heat transfer coefficient for an exchanger which is partially sprayed. Thermography is used to describe

Quantum dots (QDs) face severe heat dissipation challenges when packaged with high-power light-emitting diodes (HPLEDs). In this study, a water-cooling remote (wc-remote) structure was proposed to significantly improve the heat dissipation of QD converters in a HPLED system. The QD converter was removed from the HPLED sources to isolate the thermal power generated from the chips and was assembled on

Origami-inspired, dynamic spacecraft radiators have been proposed which utilize an expandable/collapsible surface capable of large variations in emitting surface area. In this work, an experimental prototype of this concept is realized and its performance is analyzed. In particular, we demonstrate the capability of maintaining a spacecraft component at a desired operating temperature through the expansion

This paper proposes a parallel-connected double-effect mechanical vapor recompression (MVR) evaporation crystallization system, which combines the falling film evaporator with the forced circulation evaporator. With the purpose of treating high salinity wastewater, the circulation process of the system was designed and mathematical models were established according to the mass and energy balance as

A new type of multiple jets ejector called the multi-strut mixing-enhancement ejector (MSE) has been developed in previous studies. The excellent suction and supercharging abilities of this ejector have been demonstrated through a series of cold flow tests. However, the current knowledge on MSE is limited. Numerical investigations on MSE have not been conducted in previous studies. Therefore, the present

Owing to the high specific energy consumption of conventional seawater desalination methods available hitherto, there is much motivation for designing greener desalination processes. As a greener desalination process, it should consume lower top-brine temperatures for the seawater feed as well as minimum chemical use for brine treatment. In this paper, a direct-contact spray-assisted evaporation and

A detailed experimental investigation on the critical external heat leading to the failure of lithium-ion (Li-ion) batteries was conducted using an Accelerating Rate Calorimeter (ARC) at the National Institute for Occupational Safety and Health (NIOSH). Several types of commercial Li-ion batteries were selected for the study, including an iron phosphate Li-ion battery (LFP), a lithium-titanate battery

Subway systems are rapidly developing, and their energy consumption is considerably growing. The ventilation and air conditioning system in the subway station is the key energy-consuming system. It consumes a large amount of energy every day to provide a comfortable environment for passengers, and it has therefore received increasingly more attention from researchers worldwide. In this work, the variation

Hot water storage tank is the crucial element in solar energy utilization systems. Phase change material can significantly improve the thermal efficiency and the heat storage of hot water tank. In this study, a 3-D model for hot water tank with low melting point metals, sodium acetate trihydrate, and paraffin wax was established and validated by the experimental results. The influence of the inlet

The transcritical CO2 heat pump is widely used due to its higher efficiency. Frost is inevitable at low ambient temperature, resulting in a deteriorated coefficient of performance and heating capacity. Considering the disadvantages and limitations of other defrosting methods, the hot gas bypass defrosting method was experimentally investigated in this paper. The dynamic characteristics of pressure

A new solar-driven electrochemical refrigerator model is proposed by integrating a dye-sensitized solar cell with a thermally regenerative electrochemical refrigerator. Considering various irreversible losses within the dye-sensitized solar cell, thermally regenerative electrochemical refrigerator as well as between them, mathematical formulas for the performance parameters of dye-sensitized solar

Convective heat transfer is one of the most important mechanisms of heat exchange in many of industrial devices, which covers a major part of energy-related topics. With providing large surface areas as well as intensification of flow mixing, porous media can enhance convective heat transfer in different applications. On the other hand, suspensions containing nanoparticles (i.e., nanofluids) considerably

Dispersing thermally conductive nanostructures is an effective method to improve the thermal performance of phase change materials (PCMs). For this purpose, nanocarbons, nanometals, and nano metal oxides have been used to develop nano-enhanced phase change materials (NePCMs) with unique thermal properties. However, review papers focusing on the numerical simulations of NePCMs are still scarce. The

Comprehensive understanding of the airflow temperature field in a high-temperature tunnel is critical for the deep underground engineering project. In this paper, we establish a two-dimensional axisymmetric model coupling the convective-conduction heat transfer based on the k - ε turbulence equation, by which the airflow temperature field in a high-temperature tunnel for geothermal mining is investigated

In this work, a transient numerical and experimental study is presented, focused on describing the heat transfer in a cavity filled with air, which has one vertical wall with a phase change material (PCM). The wall with PCM was exposed to constant heat flux, whereas the opposite vertical wall was kept at a constant temperature. For the theoretical study, a model for heat transfer was proposed and solved

Evaporation heat and mass transfer in open microchannels was investigated using pure liquids (ethanol, deionized water and butanol), an ordinary (non-self-rewetting) mixture (5% v/v ethanol/water mixture) and a self-rewetting fluid (5% v/v butanol/water mixture). The applied heating power ranged from 0 mW to 282.76 mW (giving heat fluxes from 0 W/m2 to 4501 W/m2) with wall temperatures ranging from

Submerged combustion vaporizer (SCV) is widely equipped in liquefied natural gas (LNG) gasification plants and receiving terminals as the emergency or peaking regasification facility. This paper constructs an energy balance-based numerical model to predict the thermal behavior of SCV operating at subcritical pressures. The heat transfer coupling between the ice formation at the water bath-side and

The thermal radiation transfer was complex due to high pressure, complicated flue gas components and abundant particles in the dilute phase region of oxy-fuel combustion pressurized fluidized bed. To carry out the radiation heat transfer, numerical simulations were done based on weighted sum of gray gases model (WSGG) and Mie theory. The Radiation Transfer Equations (RTE) of bubbling fluidized bed

To explore an effective method which can help to reduce the pressure and velocity fluctuations and promote the utilization of kinetic energy in the exhaust products of a pulse detonation chamber, a secondary oxidizer injection method has been proposed and investigated experimentally. A gasoline based valveless pulse detonation system was employed and it operated stably from 10∼50 Hz. With the extra

Hotspot formation in Gas Turbine combustor tiles can reduce their life drastically, so they require considerable attention to improve durability. In the present article, an innovative method is proposed to increase the thickness of Thermal Barrier Coating locally in the hotspot regions to enhance thermal insulation and life capabilities of combustor tiles. In this method a pre-dent is made on the substrate

Flash boiling spray has been considered as a promising atomization scheme in improving fuel-air mixture and reduce spray impingement in internal combustion engine applications. Because of its distinctive breakup mechanism, the thermal process of flash boiling spray has not been fully illustrated, in which the fluctuation of flash boiling sprays is not sufficiently studied. This work utilized a high-speed

A fluid-structure interaction model is developed to investigate the combustion and cooling performance of an aero-engine combustor. Cylindrical holes, conical holes, fan-shaped holes and console holes are introduced to reduce the thermal load of thermal barrier coatings (TBCs) in combustor, respectively. To reduce the coolant consumption, the number of film cooling holes in the first and second row

The effect of adding a plastic chimney on the top of upward horizontal rectangular heatsink under natural convection was investigated experimentally and numerically. The effect of the chimney height, length, depth, inclination, view factor, and conductivity for different fins array dimensions were investigated as well. The presence of low thermal conductivity chimney induces airflow by creating effective

Pyrolysis and autoignition of beech wood, with moisture content (MC) from 0% to 38%, exposed to power-law thermal radiation is investigated. An experimental facility capable of irradiating time-varying heat flux was utilized to conduct bench-scale tests. An analytical model was proposed to estimate the ignition time, surface and in-depth temperatures. Meanwhile, a transient numerical solver, FireFOAM

The frequency response of an evaporator for commercial refrigeration is investigated to develop a control-oriented model which balances simplicity with accuracy. The dynamics of such devices is highly nonlinear; the response curve was experimentally identified around an operating point by recording the output of the system for several sinusoidal input signals. Among the possible linear approximating

In this study, a self-designed evaporative cooler (EC) was used to coat the compressor of an R404A freezer (internal volume: 540 L) to cool the compressor through evaporative cooling and thus to improve the freezer performance. The EC was constructed using a moisture-transferring and quick-drying textile (MTQDT) to provide superior evaporative cooling. The unloaded pull-down, loaded pull-down, and

A fully coupled thermo-hydro-mechanical model in multiphase shale gas reservoirs is first developed and is then validated with analytical solutions and experimental result. Subsequently, the coupling responses are investigated to addressing mechanisms of gas recovery enhancement. Finally, a series of parameter sensitivity analyses are implemented to investigate the effect of parameters on gas recovery

The transcritical carbon dioxide heat pump cycle has been drawing much research interest due to its environmental friendliness and the thermodynamic features of carbon dioxide. However, there is one concerning issue, which is the huge exergy loss associated with the isenthalpic process in the expansion valve. In the current study, a new transcritical carbon dioxide heat pump cycle is proposed, where

A city-scale hourly heat demand model for district heating (DH) is proposed by combining a physical and data-driven approach. The physical heat demand model is based on lumped building parameters of the city determined from easily available data. It enables to investigate the effects from activity, structural, and technology changes on heat demand, e.g. building energy efficiency improvements or climate

Experimental study and numerical simulation work were carried out to investigate the natural convection performance in presence of internal heating, strong turbulence and phase change. The experiments were performed in large-scale facility with two simulants for comparison: water without solidification and molten salt with solidification. Three heating power levels were conducted for each simulant

The utilization of renewable energy and waste heat recovery can effectively alleviate the ongoing energy crisis and environmental pollution. The organic Rankine cycle has been proven to be reliable in converting low-to-medium-grade waste heat to power. The fluid selection is a crucial factor in the organic Rankine cycle design procedure, because the cycle performance depends mainly on the thermophysical