Methanol direct-injection achieves direct injection of diesel and methanol in the cylinder by using two independent fuel injection systems. This yields an extremely high methanol substitution rate and extremely low pollutant emissions. Due to these advantages, three injection strategies are proposed to investigate this injection method: D/M mode and M/D mode are where methanol injection occurs later

Liquid cooling system was critical to keep the performance of lithium-ion battery due to its good conductivity to keep battery working in a cool environment. In this study, a novel double helix cooling structure was designed for an 18650 lithium battery. The numerical simulation was carried out to investigate the effects of the coolant mass flow rate (M), helix groove pitch (P) and flow diameter (D)

Spray cooling is a promising approach to efficient removal of heat and has attracted increasing interest with its excellent characteristics, such as strong heat exchange capacity, low flow rate, and uniform temperature distribution. Recently, high voltages have been successfully employed in electrospray (ES) cooling, which has improved cooling performance but has poor heat transfer control. We experimentally

Compared with conventional second-loop ground-coupled heat pump, direct-expansion ground-coupled heat pump can achieve higher energy efficiency. To maximize the heat exchange rate of direct-expansion heat exchanger, a novel direct-expansion downhole heat exchanger is proposed in this study, using supercritical pressure CO2 as the refrigerant. The heat exchanger is placed inside a closed water well

Free-piston internal combustion engines (FPICEs) have many potential advantages, such as simple structure, high conversion efficiency, multi-fuel feasibility and multi-output power types, because their piston motion is not restricted by the crankshaft system. Therefore, FPICEs have received considerable attention worldwide for many decades. According to recent research, the typical types of FPICEs

With the increasing demand for crude oil reserves, storage tanks are being developed on a large scale, and heating energy consumption is gradually increasing. Hence, it is necessary to study energy utilization. The variable physical parameters of crude oil and dynamic thermal environment are considered to establish a coil heating theoretical model of a large crude oil storage tank. On this basis, according

The performance of electrochemical energy storage technologies such as batteries and supercapacitors are strongly affected by operating temperature. At low temperatures (<0 °C), decrease in energy storage capacity and power can have a significant impact on applications such as electric vehicles, unmanned aircraft, spacecraft and stationary power storage. In this work, the discharge behaviour of nine

The mixed turbulent convection heat-transfer characteristics of supercritical CO2 (S-CO2) heated in both vertical and horizontal oriented helically coiled tube (HC-tube) is investigated via experimental and numerical methods. Firstly, the coupled equations of flow direction, buoyancy force and centrifugal force in HC-tube are established. Then, the influence of the three factors on axial and radial

Renewable energy sources (RES) have become a favoured alternative to fossil fuel energy generation that has been driven by environmental concerns. Their intermittent nature has meant that gas turbines have remained relevant to support them as a backup. Current grid operation requires gas turbines to operate at as low power as possible when their demand drops, and also ramp-up quickly when power generation

For the purpose of reducing the weight and cost of low melting point alloy (LMPA) heat sink, a novel dual-phase change material (PCM) heat sink by using both LMPA and paraffin was proposed in this paper. A numerical model was developed by considering the conduction and natural convection in paraffin and the pure conduction in LMPA. The semi-implicit pressure-linked equation algorithm was adopted to

Onshore oilfields are considered as geothermal fields producing hot water in the high water cut stage (HWCS). In the present study, a supercritical CO2 power cycle is proposed to recover the heat of the hot water obtained at a temperature close to 140 °C from the oilfield in the HWCS. The output power of the supercritical CO2 power cycle is expensed to run the compressor of an ejector expansion CO2

Energy storage systems based on phase change materials are very innovative and useful in different engineering applications. The present study deals with numerical simulation of energy transport performance in a shell and tube energy storage system, including the paraffin wax or copper foam insertion with paraffin wax. The mathematical description of the considered problem consists of the basic equations

The internal temperature of the battery is important for the design of battery thermal management and battery safety; however, it is difficult to be tested and seldom studied. A method of embedding thermocouples inside a prismatic Li[Ni1/3Co1/3Mn1/3]O2 (NCM) lithium-ion battery was developed to study the temperature inconsistency between the battery interior and the surface. Six thermocouples were

In this paper, the analysis of an existing calcium chloride evaporation unit was performed to cut primary energy use and harmful emissions. This paper proposes the use of several approaches for retrofit of existing calcium chloride production. The existing process's energy efficiency was examined to identify drawbacks and bottlenecks and provide the pathways for proper process modification. The methodology

This paper reports thermal (burner) and mechanical (blunt trauma and nail penetration) abuse experiments on electric vehicle lithium ion modules comprising eight 56.3 Ah lithium nickel manganese cobalt (NMC) pouch cells. The aim of project part of which is described in this paper was to study the problem of thermal runaway in lithium ion batteries under different abuse conditions and at different SOC

Combined heat and power production in micro- to small-scale is one main part of the decentralization of energy production. Concepts using solid biogenic fuels to provide power and heat are manifold, but often focus on a nominal power output above 50 kWel. Moreover, slagging or fouling issues in combustion processes provoke reduced electrical efficiencies and short maintenance intervals. This research

Advanced parabolic trough systems are the promising technologies for the production of usable heat and electrical power. Here we study the effects of hot water temperature adjustment concept and optical concentrator on the thermal and electrical efficiencies of a new PTC/HTTEG configuration, which comprises parabolic trough concentrator and hybrid tubular thermoelectric generator. The hybrid tubular

The energy consumption in the built environment represents one of the major contributors of carbon emissions to the atmosphere. This leads to the need for a transition in the building sector and the introduction of policies that pursue high efficiency in residential and non-residential buildings with an increasing share of renewables. The benefit of the use of thermal energy storage is widely recognized

The CO2 transcritical Rankine cycle (CO2-TRC) has a great potential for the application in concentrating solar power (CSP) system due to the advantages of using low- and medium- temperature sources and compact structures. However, the cloud passages always lead to the suddenly varied heat input to the system, while understanding the system’s response to the cloud disturbance may enable the operational

Air compression is the main energy consumption process in cryogenic air separation units (ASUs), while compression waste heat occupies over 60% of the total compression power. However, the compression waste heat has not yet been recovered in existing ASUs, implying a great potential for energy efficiency improvement. In this paper, an organic Rankine-vapor compression cycle (ORVC) assisted three-stage

The sealing flow will inevitably affect the cooling airflow quality in a second air system of an aero-engine. In this study, theoretical derivation and numerical simulation were conducted to establish a modified mixing model that considers both the torque and the source of the mixing flow. Then, the effect of the sealing flow can be evaluated using the modified mixing model. The results demonstrate

Targeting at addressing the low exergy efficiency of micro thermophotovoltaic (MTPV) system, a novel micro combustor with internal spiral fins is proposed. The geometrical parameters, including internal spiral fin number, length and pitch distance, on the thermal performance and exergy efficiency are numerically investigated. The introduction of internal spiral fins can effectively improve the exergy

Heat exchangers for residual heat recovery in coal-fired power plants face the issues of low heat transfer efficiency of flue gas side and the fly ash fouling. However, heat transfer enhancement structures always increase the fouling on the fin. Efficient methods are required to improve both heat transfer and anti-fouling performance of the heat exchanger. In present study, the thermal-hydraulic and

An experimental investigation of a Ranque-Hilsch vortex tube has been performed. The investigation focuses on the effects that pressure magnitude, pressure drop and pressure ratio have on the temperature drop between the inlet and the cold outlet. The Ranque-Hilsch vortex tube used in the experiments was designed through consideration of a large body of experimental data consolidated from existing

To maintain efficiency in advanced aero-engines, it is crucial to set high limits for the Operating Pressure Ratio (OPR) and Turbine Entry temperature (TET). This can be achieved using a Cooled Cooling Air (CCA) heat exchanger, which precools the compressed air with the bypass stream before the compressed air enters the turbine to cool the blades. The aim of the present study was to improve the aero-thermal

Thermal energy storage based on sorption method is attractive in view of energy storage density, storage period, and flexibility. Three-phase sorption thermal energy storage is advantageous from high energy storage density, but its temperature lift is low. Besides, further energy storage density enhancement is needed to make the storage system more compact. In this paper, multi-functional three-phase

Battery thermal management system is one of the most essential parts for the battery pack in electric vehicles. In this paper, a new battery thermal management system is developed through the combination of the battery pack structure optimization and the cooling strategy design. First, a new battery pack equipped with the hollow spoiler prisms based on the aligned battery pack is designed to improve

A 3D modeling of the fluid dynamics and heat transfer in an advanced free-piston Stirling engine was conducted. The transient and conjugate fluid dynamics and thermodynamics of the coupling fluid-solid domain over the working cycle were comprehensively investigated. The comparisons among different turbulent CFD models and Sage result of the engine were performed. Results indicate that the k-epsilon

A new tank design with variable outlets at different heights is lately proposed. In this paper, the new tank design is applied to a thermosiphon solar water heating system. The performance of the thermosiphon system is investigated for space heating of an office building. A mathematical model of the thermosiphon system is developed and validated against the experimental data. With the mathematical

Local air-side heat transfer coefficients (HTCs) of real-scale heat exchanger fins have been experimentally investigated in the current study. A recently developed absorption-based mass transfer method has been employed to visualize and obtain two-dimensional HTC distributions on different fins at a high resolution (8.6 µm). The process involves a mass transfer from airflow to a color change thin film

Inductive Power Transfer (IPT) technology is a promising solution for wireless charging of Electric Vehicles (EVs). Given the expected uptake of IPT technology for both stationary and in motion in-road charging, many technical challenges regarding the electromagnetic field and thermal aspects need to be overcome to generate cost-effective and reliable solutions. One particular design constraint of

Organic Rankine Cycles (ORCs) are recognized as suitable systems to convert the thermal energy from low-grade heat sources to electricity. However, their performance and reliability are subjected to several deficiencies especially at micro-to-small scales. In this work, the impact of the expander lubricant oil on the performance of the heat exchangers and the scroll expander of a non-regenerative,

Liquid cooling is an effective method for thermal management of high-power battery packs. A number of studies have shown that the general methods to enhance heat transfer performance by increasing flow rate will significantly increase pump power consumption. Here, in order to reduce the pump power consumption while enhancing heat transfer, the mini V-shaped ribs is used to optimize the structure of

This study investigates the integrated heat pump system of a green-field dairy located in Bergen, Norway. The purpose of the study is to determine the energy consumption and system performance. The dairy features a novel and innovative solution of a fully integrated energy system, employing high temperature heat pumps such as the hybrid absorption-compression heat pump (HACHP) with natural refrigerants

In this study, single-phase H2O/LiBr solution heat transfer and frictional pressure drop characteristics in plate heat exchangers (PHEs) with two different chevron angles are experimentally evaluated for triple-effect H2O/LiBr absorption chiller applications. The test PHEs are single-pass exchangers with 20 plates. Chevron angles are 78.5° and 55.7° for high- and low-theta PHEs, respectively. Heat

The proliferating thermal runaway accidents are still the main obstacle that hinders the extensive applications of lithium-ion batteries. An abuse condition triggering thermal runaway of particular interest is local heating, which is the direct and common cause. However, a comprehensive simulation and analysis of thermal runaway under local heating from the perspective of heat generation, external

The improvement of gas turbines flexibility has been driven by more use of renewable sources of power due to environmental concerns. There are different approaches to improving gas turbine flexibility, and they have performance implications for the bottoming cycle in the combined cycle gas turbine (CCGT) operation. The CCGT configuration is favourable in generating more power output, due to the higher

The auxiliary requirement of a solar water heating system is an index of the end-users cost and, thus, the feasibility of the system. Within this study several locations worldwide with high and low solar radiation and electricity prices in latitudes of 0, 15, 30, 45 and 60°N have been selected and the effect of employing a Compound Parabolic Collector (CPC) on the yearly auxiliary energy saving of

The solar thermoelectric generator (STEG) is a promising alternative terrestrial solar power generation device due to its ability to utilize almost full solar spectrum. Many researches have been carried out to improve its efficiency. Some improved STEG has achieved remarkable efficiency in the laboratory. However, its performance in practical situations has been few studied, which limits its practical

In view of the global energy crisis, energy saving in high-temperature thermal production is urgent. The traditional rock wool and composite silicate board cannot meet the requirements of high efficiency thermal insulation for heavy oil recovery pipe due to their poor insulation performance, and the emerging SiO2 aerogel production has poor shielding ability to infrared thermal radiation, resulting

The problem that the exact nonlinear connection between fluids flow and heat transfer in direct contact heat evaporator was studied. The direct contact heat evaporator structure can be optimized and direct contact heat transfer process can be improved with the help of the optimum matching relationship between the complex flow and heat transfer. The methods used are the signal processing technology

This study develops a wet steam modelling to solve the phase change process inside the linear blade cascade of a steam turbine. The comparative study is carried out to understand the impact of the dry gas model and wet steam model on predicting the flow behaviours in a steam turbine. The effect of the cutback of the trailing edge on the flow structure and nonequilibrium condensation is evaluated in

It is crucial for the diesel particulate filter (DPF) that the exhaust temperature at the DPF inlet is well managed and accurately controlled during the thermal regeneration process, in order to ensure the integrity of the filter and improve regeneration efficiency simultaneously. However, this is challenging because the DPF and the upstream diesel oxidation catalyst are complex systems with complicated

Double-wall cooling structures are commonly used to enhance the heat transfer in combustor liner and aerofoil internal cooling within gas turbine engines and other industrial applications. This is the first study to adopt a novel reverse jet impingement technique into a double-wall cooling structure in order to achieve a higher heat transfer rate with relatively lower pressure drop. This paper uses

Organic Rankine Cycle (ORC) is widely investigated for low-grade waste heat recovery, but its performance deteriorates under heat source with thermal power fluctuations. As the effects of fluctuating heat source on ORC system performance is less investigated, the operating rules of ORC systems under fluctuating heat source are not clear. In this study, the effects of fluctuating amplitude and period

Fundamental understanding of heat generation of lithium-ion batteries during operations is crucial to the cost-effective and efficient design of a thermal management system (TMS) in electric vehicles. Accurate characterization of the heat requires a calorimeter that meets inherent dynamics of the heat with accuracy. Therefore, we have developed an isothermal calorimeter using the thermoelectric assemblies

Thermoacoustic refrigeration technology is a green alternative for the conventional refrigeration system in vehicles. The former uses environmentally friendly inert gases whereas the latter uses chemical refrigerants that can have severe impacts on the environment. In order to apply thermoacoustic technology in the automobile industry, the size and the weight of plausible thermoacoustic refrigerators

CO2 systems used in refrigeration are becoming more complex with the aim of improving their energy performance. Parallel compression is one of the implemented solutions to enhance the performance of the plants. However, an optimization process is required to operate this system at high performance and its operation is subjected to physical limitations in real plants. This work presents the experimental

The faster charge/discharge of lithium-ion batteries that power unmanned aerial vehicles (or drones) increases heat emission substantially, thus requiring effective thermal management solutions. In this study, we present such a thermal solution for prismatic lithium-ion battery cells managed by “naturally aspirated air-convection” in tetrahedral lattice porous cold plates as a multi-functional application

A study was conducted to investigate heat transfer in a ground heat exchanger (GHE) system with a novel capric acid-lauric acid eutectics/expanded graphite (EG) composite PCM. The composite PCM was prepared and analyzed. The optimal mass ratio of fatty acid to EG was 10:100 with a melting heat of 134.13 kJ/kg. The thermal performances of GHE system with different fraction ratios of the composite PCM

Terry steam turbines are widely used in various industries because of their robust design. Within the nuclear power generation industry, they are used in the Reactor Core Isolation Cooling System to remove decay heat during reactor isolation events. During the Fukushima Daiichi nuclear power station disaster in Japan in 2011, the Reactor Core Isolation Cooling System and associated Terry turbine operated

The paper presents the dynamic characterization of a novel CO2 system designed for the refrigerated transport sector, when equipped to a medium-size refrigerated truck, during a daily typical long-distance delivery mission. The system takes advantage of a two-phase ejector to improve its performances and an auxiliary evaporator to extend the ejector operating range towards mild ambient temperatures

Natural gas (NG) is delivered to homes and businesses through a complex pipeline network that mainly consists of high-pressure main feed lines and many low-pressure local distribution lines. To date, throttling valves have been employed to reduce the NG pressure between the two types of pipeline, leading to the loss of the work potential generated by the expansion of pressurized NG in the NG supply

Hot combustion gas in gas turbines can be ingested into the mid-passage gap between the blade platforms, resulting potentially a catastrophic damage. To prevent the ingress of hot gas, the blade platform underneath cavity is pressurized with purge air. Seals are typically installed in the mid-passage gap to minimize the purge air requirement. Under inadequate back flow margin, ingress of the main flow

Stirling/pulse tube hybrid refrigerator, a novel refrigerator composed of Stirling refrigerator as the first stage and pulse tube refrigerator as the second stage, has great potential in space detection applications. This kind of hybrid refrigerator exhibits outstanding comprehensive performance in reliability, efficiency and compactness due to its unique structure. However, there is usually a contradiction

This work focused on presenting a multivariate inverse artificial neural network (ANNim) by developing two functions coupled to metaheuristic algorithms to increase a parabolic trough collector (PTC). This work aims to provide a new method capable of improving the thermal efficiency of a PTC by determining multiple optimal input variables. At first, two ANN models carried out to predict the PTC thermal

Electrically insulating phase change composite materials (PCCMs) with lightweight, good thermal management performance, high stability and high mechanical strength are strongly desired for lithium-ion battery (LIB) thermal management. This research study presents a group of PCCMs based on the integration of reduced graphene-oxide aerogel beads (rGOAB), phase change materials (PCMs) and thermally conductive