Qiuwang Wang

• PhD
• Xi'an Jiaotong University

This study proposes a novel multi-scale numerical method for thermal-mechanical analysis of mini-channel heat exchangers (MCHEs) under internal fluid pressure and temperature loads. The method comprises a macro-scale model for global analysis and a meso-scale model for detailed sub-model analysis, specifically focusing on the internal fluid pressur...

To achieve zero carbon emissions, replacing conventional fuels in combustion engines and gas turbines with carbon-free fuel is of utmost important. While hydrogen is effective in mitigating climate change, the cost challenges in liquefaction and transportation persist. Ammonia (NH3), a carbon-free fuel with its higher volumetric energy density and...

Hierarchically porous materials have enormous potential in energy storage, thermal management, desalination, biomedicine, and catalytic reactions for their superior thermophysical properties, high specific surface area, low density, and excellent accommodation capability with volume and thermal variation. As the demand for sustainable energy soluti...

The flexibility of future power production systems must be maximized in order to offset the unpredictability of non-dispatchable energy from renewable sources. The absence of state policies and strategies to encourage investment in exploiting solar energy is why it is not widely used in Africa. In light of this, this research first aims to carry ou...

Mini-channel heat exchanger are widely used due to their compact structures and high efficiency. Integrating heat exchangers with triply periodic minimal surfaces (TPMS) has shown great potential to optimize the flow and heat transfer performance. In this study, Gyroid (G), Diamond (D) and IWP type TPMS based heat exchangers are constructed in thre...

Porous media play a key role in the fields of energy conversion, thermal management and energy storage due to their outstanding advantages such as large surface area, light weight and complex channels. In this paper, the homogeneous porosity and gradient porosity W type porous structure (porosity ε=0.3∼0.5, hydraulic diameter dh=1.33∼3.86 mm) were...

CO 2 hydrate is a potential cold thermal energy storage material with latent heat of 500 kJ/kg, however, the dissociation principle of CO 2 hydrate is different from that of solid-liquid phase change materials and therefore, exploring the dissociation mechanism of CO 2 hydrate is of great significance for efficient cold storage. In this paper, a ne...

Microchannel heat exchangers are characterized by high heat transfer efficiency and compact volume. The accuracy of microchannel wall temperature measurement directly affects the measurement result of the heat transfer coefficient. The water bath can control the heat flux in the microchannel heat transfer experiment with good uniformity of heat flu...

Printed circuit heat exchanger (PCHE) has the potential to replace the traditional heat exchangers in lead–bismuth fast reactors due to the high compactness. In this work, a segmented Log-Mean Temperature Difference (LMTD) method is applied to design a PCHE used for a 280 MWth lead–bismuth fast reactor. The structural strength is checked based on t...

Relativistic backward wave oscillator is a high-power microwave generator with great application potential. Since a large amount of waste electron are deposited on the collector, the temperature of the collector rises, which reduces the safety and stability of relativistic backward wave oscillator. The collector temperature characteristics are calc...

Thermochemical heat storage (TCHS) technology is widely concerned for its high energy storage density (ESD) and long-term storage of energy in the form of chemical energy for long-term thermal storage applications. TCHS with hydrated salt as the thermochemical material (TCM) has low regeneration temperature, clean reaction products, and appropriate...

Printed circuit heat exchangers (PCHEs) have great potential to be employed in the advanced nuclear reactor systems. In this work, the equivalent thermal conduction resistance of PCHE is studied. The influences of thermal convection resistance are analyzed. The results indicate that the equivalent thermal conduction resistance of PCHEs with unequal...

The printed circuit heat exchanger (PCHE) is one of the leading heat exchanger candidates in the supercritical carbon dioxide Brayton cycle, which has high efficiency and compactness. In the present paper, a novel type of PCHE with airfoil fins was proposed and tested. The effect of the thermal resistance variation on the heat transfer performance...

Improving the heat transfer performance of phase change material (PCM) plays a crucial role in designing efficient latent heat thermal energy storage (LHTES) systems. The purpose of this study is to address and elucidate the effects of the metal foam-fin hybrid structure and the inclination angle on the phase change process by using the numerical s...

Phase change materials (PCMs) have been considered suitable energy materials to address the mismatch between energy demand and supply to improve the utilization efficiency of the latent heat thermal energy storage (LHTES) system. However, the relatively low thermal conductivity of PCMs leads to an undesirable thermal response rate of the LHTES syst...

As the primary working medium in moving bed heat exchangers, solid bulk materials are composed of multiple size particles. To clarify the effect of particle size distribution (PSD) on heat transfer, the discrete element method (DEM) is used to study the flow and heat transfer of binary size particle flow around a circular tube. The heat transfer mo...

Effective cooling technology is intensely demanded to cool the electronic devices within small space under high heat flux. Mini-grooved flat heat pipe (FHP) with simple structure, close contact with heat source, uniform temperature and high thermal conductivity can satisfy the demand of transferring the great heat rapidly and weakening the hot spot...

Sharing advantages of high compactness, SCO2 Brayton cycle and thermoelectric generator are both considered promising energy conversion solutions and have attracted great attention due to the increasing energy shortage and global climate change. The integration of thermoelectric generators in the SCO2 Brayton cycle will remain the inherent advantag...

Heat exchanger network synthesis is an essential optimisation tool for Process Integration, particularly in energy-intensive industries. Proper design or retrofit of heat exchanger network can enable energy conservation, efficiency improvement, and process debottlenecking. Many earlier pieces of research have focused on the impact of the network st...

The heat exchanger is an essential component of the supercritical CO2 Brayton cycle. To attenuate the temperature fluctuations in the cycle, this study proposes a new structure with phase change materials embedded in the printed circuit heat exchanger. This structure package can contain a variety of phase change materials in a stepwise arrangement...

The efficient and accurate prediction of fuel pyrolysis and surface coking in regenerative cooling systems is critical to developing hypersonic vehicles. This study adopts a combined method based on the chemical reaction kinetics and corresponding states principle to establish a simplified RP-3 fuel pyrolysis model. The chemical reactions are decre...

Hydrogen cooler is a key equipment of the precooling unit in hydrogen refueling stations with the requirement of high heat transfer efficiency, high compactness and high pressure resistance. Printed circuit heat exchanger is a promising candidate for the hydrogen cooler due to its great performance on extremely high pressure and high temperature wo...

The intermediate heat exchanger (IHX) is one of the key components in advanced nuclear reactor power generation system. Printed circuit heat exchanger (PCHE) with mini-channels is a good candidate for the IHX. But the whole PCHE with tens of thousands of mini-channels is hard to be modeled and calculated at high temperature. Thus, the homogenizatio...

Because of the low charging temperature, salt hydrate-based adsorption thermochemical energy storage (TCES) is currently a significant technology that promises long-term energy storage. A corrugated-shaped heat storage unit (HSU) in which embedding porous metal bracket is proposed in this work to enhance heat transfer between the thermochemical mat...

Fuel pyrolysis is a common phenomenon in regenerative cooling channels. However, the alkenes and aromatic hydrocarbons produced by thermal cracking tend to deposit on the channel surface, leading to local heat transfer deterioration, corrosion resistance reduction, or blockage. This study establishes a numerical investigation at a supercritical pre...

Heat exchanger network synthesis (HENS) is an effective tool for heat recovery in chemical and petrochemical industries. This study aims to show a method for HENS with the consideration of different shell-side flow arrangements in shell-and-tube heat exchangers. The proposed MINLP model is modified from the single-period stage-wise superstructure m...

Micro gas turbine is a typical distributed energy resource system. The temperature of the burning gas in the combustor reaches 1000 K or even more, which makes a huge temperature difference in the combustor an interesting topic for heat recovery. In this work, thermoelectric devices are used for heat recovery in the combustor of the micro gas turbi...

The development of phase change materials (PCMs) is hampered by issues like leakage, poor thermal conductivity, and poor light absorption. In this study, we innovatively combined modified melamine foam (MF) and graphene nanoparticle (GNP) to address these defects of PCMs in the solar-thermal energy system. The MF was modified to endow the solar-the...

The majority of prior experimental and computational studies of the energy tank system employed in solar power plant systems have been focused on parametric studies. The interaction effects of several input factors on the thermal behavior of the TTES tank configuration using RSM have not yet been addressed. A predictive approach depending on the re...

Printed circuit heat exchanger (PCHE) is considered a promising candidate for accelerator driven systems (ADS) due to its high compactness and efficiency. The preeminent high-temperature, high-pressure and corrosion resistance enables it to withstand the severe conditions of ADS and ensure the safe and efficient operation. In this paper, a PCHE app...

The discontinuous airfoil-fin printed circuit heat exchanger is a leading candidate due to its high compactness, high efficiency, and ability to endure extreme conditions. In this paper, an unusual asymmetric airfoil-fin heat exchanger is experimentally investigated using the supercritical carbon dioxide and water experimental system. The effects o...

The current research examines how increasing the thickness of the phase change material (PCM) layer impacts the thermal and economic behavior of the hybrid sensible-latent heat storage reservoir utilized in solar power plants in order to prevent temperature fluctuations at the end of discharge cycles. On the basis of two-phase dispersion-concentric...

A heat transfer model based on the discrete element method was developed to investigate the effect of the trapezoidal corrugated plate on heat transfer. Particles flow along a trapezoidal corrugated plate unit (TCPU) were compared with that along a flat plate, and the appropriate base angles of the trapezoidal bulge were searched. In the upstream r...

Gravity-driven granular flow has been the heat transfer mediums in moving bed heat exchangers, which play vital roles in industrial heat saving and solar energy utilization. However, the heat transfer mechanism of granular flow is still worth of investigating around the tube bank. In this work, the aligned tubes were arranged in the moving bed, and...

Supercritical CO2 Brayton cycle is widely used in industry because of its small compression work and considerable cycle efficiency. In this work, dynamic simulation numerical models of Supercritical CO2 Brayton cycle with three typical layouts (recompression, reheating, intercooling) and a newly proposed layout are developed using thermodynamic equ...

To further improve the performance of thermal energy storage (TES) system with phase change materials (PCMs), this paper proposed a novel method, i.e. combining the additions of TiO2 nanoparticles, metal foam and the provision of ultrasonic field, investigated its synergetic effects in enhancing conduction and convection heat transfer. The thermal...

An efficient battery thermal management system (BTMS) is crucial to ensure the working temperatures of the battery are within a suitable range and therefore guarantee performance. However, the current BTM methods not only are limited by weight, space, and energy consumption, but also hardly surmount the contradiction of battery cooling at high temp...

Photovoltaic (PV) devices play an increasingly important role in solving the energy crisis. However, the conversion efficiency of the PV panel is small. Cooling of PV panels using phase change devices is an effective way to improve the working performance of PV panels. A phase change device with a two-level arrangement of metal-organic phase change...

Printed circuit heat exchanger is considered as an ideal candidate for floating storage and regasification unit of liquefied natural gas due to its high compactness and efficiency. The flow maldistribution is an essential issue in practical applications of the printed circuit heat exchanger, which leads to the performance degradation. In this study...

Condensation is a phase-change heat-transfer phenomenon crucial in many industries involving latent heat release and mass transfer. Shell-and-tube condensers are essential contributors to the condensation process, and their tube bundles serve as a substrate. Here, the thermal-hydraulic characteristics of condensation in a longitudinal-flow shell-an...

The transition from gasoline automobiles to electric vehicles (EVs) is promoted as an alternative to reduce greenhouse gas (GHG) and pollutant emissions. The performance of EVs depends entirely on the performance of a power battery, especially the lithium-ion (Li-ion) battery, which is very sensitive to temperature. The temperature of Li-ion batter...

Due to the prominent advantages of high energy density and long-term energy conservation ability, salt hydrate-based gas-solid thermochemical energy storage (TCES) is a promising technology for effectively employing low-grade energy such as industrial waste heat and minimising fossil fuel-based sources depletion. As an innovative thermal energy sto...

Given that the outstanding benefits of high energy storage density (ESD) and long-term energy storage ability with ignorable heat losses, thermochemical energy storage (TCES) in salt hydrates is a promising way to bridge the gap between supply and demand sides for renewables in residential heating. In this article, the hydration process (for heat d...

For the current thermal performance of the concentrating solar power (CSP) plants, the thermocline storage approach in a packed bed is recommended to be a favorable thermal energy storage (TES) system because of its cost effectiveness. Based on this, several parametric studies were performed to examine the thermal efficiency of various configuratio...

Liquefied natural gas (LNG) is a clean energy source that shows great potential for further development. In the production and transportation process of LNG, heat exchanger is an essential device that conducts the liquefaction and vaporization operations. With the booming development of floating LNG (FLNG) technology, higher requirements have been...

Ash deposition in flue gas heat exchanger affects its heat transfer performance and lifecycle, which becomes a crucial factor restricting the efficient recovery and utilization of flue gas waste heat. In this paper, a numerical method was established to investigate the characteristics of ash deposition in tube bundle heat exchangers. An integrated...

In this paper, the dehydration (heat charge) and hydration (discharge) reaction kinetics of thermochemical sorbents synthesised in our previous work is established by the isothermal method, with the aim of understanding their thermochemical conversion behaviour and supporting the development and validation of related numerical simulation tools. The...

Supercritical carbon dioxide (SCO2) Brayton cycle has been widely used in a variety of industrial settings. In this work, three commonly used SCO2 Brayton cycle dynamic numerical models at different heat source temperatures are built with MATLAB and Simulink software, and the key parameters of three commonly used Brayton cycle models (recompression...

The partial replacement of a hydrogen-based gaseous fuel for solid fossil fuel plays a key role in increasing the sustainable energy share in sinter plants. The imbalanced heat distribution is a long-standing problem that can adversely affect the energy efficiency of sintering process, especially in the near-inlet region. In the present study, the...

The optimal performance of a Li-ion battery is directly impacted by temperature. In order to control the temperature rise and provide even temperature distributions in the battery pack, a thermal management scheme comprises thin heat sinks with multiple phase change materials (PCMs) and air channels is investigated in this paper. The cooling perfor...

To realize the heat transfer between granular flow and sCO2 cycle, moving bed heat exchangers have been widely applied in Concentrating Solar Power systems. This work developed a prediction model for heat transfer enhancements and dynamic control strategies in a shell-and-plate moving bed heat exchanger. For fast evaluation of heat transfer perform...

Czech-Chinese Project Transmission Enhancement and Energy Optimised Integration of Heat Exchangers in Petrochemical Industry Waste Heat Utilisation is a joint project of Czech Republic, SPIL, Brno University of Technology-VUT Brno and the People's Republic of China, Xi'an Jiaotong University, Xi'an, Shaanxi. The 3 y project contributes to solving t...

Composite Phase Change Materials (CPCMs) using metal foam as core material are highly promising for thermal management of photovoltaics. Selecting a proper CPCM for a given application is challenging. To address this, we developed a pore-scale lattice Boltzmann model based on X-ray micro-Computed Tomography to describe the complicated microstructur...

The Chinese government made a pledge to the international community that CO2 emissions in China will peak before 2030 and carbon neutrality will be achieved before 2060. Iron ore sinter production is an important source of carbon emissions in China. Indeed, the uneven heat distribution in a sintering bed is a long-standing problem that significantl...

Printed circuit heat exchangers with high heat transfer efficiency, small volume and high pressure resistance are usually chosen as a precooler for the supercritical carbon dioxide Brayton cycle. The supercritical carbon dioxide channel has high pressure and small mass flow rate, but the water channel has low pressure and large mass flow rate. The...

Photovoltaics, as a direct technology to convert sunlight into electricity, possess significant potential to deal with ever-increasing environmental problems and the desire to reduce the use of fossil fuels. Thermal stability of photovoltaics is of major concern when considering large-scale commercialization under conditions in which device degrada...

An elliptical-like combined tube (ELCT) is proposed for the shell-and-tube moving packed bed heat exchanger. The heat transfer of particle flow around the ELCT is numerical studied. The kinetic energy ratio, contact number, contact time and heat transfer coefficient are analyzed. It is found that, the heat transfer performance of the ELCT is simila...

Heat recovery from granular flow in moving bed heat exchangers has wide industrial applications. However, more knowledge is still necessary for the heat transfer enhancement. For the slow descending of random particles, the flow structure has crucial roles on the heat transfer by conduction and radiation. In this paper, the effect of tube inclinati...