Thermoelectric (TE) materials have the capability of converting heat into electricity, which can improve fuel efficiency, as well as providing robust alternative energy supply in multiple applications by collecting wasted heat, and therefore, assisting in finding new energy solutions. In order to construct high performance TE devices, superior TE materials have to be targeted via various strategies. The development of high performance TE devices can broaden the market of TE application and eventually boost the enthusiasm of TE material research. This review focuses on major novel strategies to achieve high-performance TE materials and their applications. Manipulating the carrier concentration and band structures of materials are effective in optimizing the electrical transport properties, while nanostructure engineering and defect engineering can greatly reduce the thermal conductivity approaching the amorphous limit. Currently, TE devices are utilized to generate power in remote missions, solar-thermal systems, implantable or/wearable devices, the automotive industry, and many other fields; they are also serving as temperature sensors and controllers or even gas sensors. The future tendency is to synergistically optimize and integrate all the effective factors to further improve the TE performance, so that highly efficient TE materials and devices can be more beneficial to daily lives.

https://espace.library.uq.edu.au/view/UQ:722903/UQ722903_OA.pdf

High Performance Thermoelectric Materials: Progress and Their Applications

Solar energy systems (SESs) are considered as one of the most important alternatives to conventional fossil fuels, due to its ability to convert solar energy directly into heat and electricity without any negative environmental impact such as greenhouse gas emissions. Utilizing nanofluid as a potential heat transfer fluid with superior thermophysical properties is an effective method to enhance the thermal performance of solar energy systems. The purpose of this review paper is the investigation of the recent advances in the nanofluids’ applications in solar energy systems, i.e., solar collectors (SCs), photovoltaic/thermal (PV/T) systems, solar thermoelectric devices, solar water heaters, solar-geothermal combined cooling heating and power system (CCHP), evaporative cooling for greenhouses, and water desalination.

Applications of nanofluids in solar energy: A review of recent advances

Thermoelectric cooler and thermoelectric generator devices: A review of present and potential applications, modeling and materials

Thermoelectricity for IoT – A review

All machines from jet engines to microprocessors generate heat, as do manufacturing processes ranging from steel to food production. Thermoelectric generators (TEGs) are solid-state devices able to convert the resulting heat flux directly into electrical power. TEGs therefore have the potential to offer a simple, compact route to power generation in almost every industrial sector. Here, in a Roadmap developed with wide-ranging contributions from the UK Thermoelectric Network and international partners, we present the science and technology that underpins TEGs. We outline how thermoelectric (TE) technology capable of generating power outputs from microwatts to tens/hundreds kW, and potentially to MW, can have an impact across a wide range of applications in powering devices, ranging from medical to building monitoring, the internet of things, transportation and industrial sectors. The complementary application of TE technology in cooling affords additional opportunities in refrigeration and thermal management. Improved waste-heat harvesting and recovery and more efficient cooling offer significant opportunities to reduce energy usage and CO2 emissions. We provide an overview of the key challenges associated with the development of new materials and devices that offer higher power output, while matching TE solutions to the wide range of applications that would benefit from energy harvesting. There is an existing supply chain to develop, manufacture and integrate thermoelectric devices into a broad range of end-user sectors all with global market potential: the full realisation of which will require new state-of-the-art manufacturing techniques to be embraced in order to drive down costs through high-volume manufacturing to widen the application base.

/pdf/realising-the-potential-of-thermoelectric-technology-a-37fy65bi0p.pdf

Realising the potential of thermoelectric technology: a Roadmap

Combustion Model Based Explanation of the P max and IMEP Coupling Phenomenon in Diesel Engine

A Predictive Model of P max and IMEP for Intra-Cycle Control

A control-oriented, low computational cost nitrogen oxides emissions model for a diesel engine is presented. The model is based on zero-dimensional one-zone nitric oxide formation thermodynamics. The main inputs to the model are measured cylinder pressure, engine speed and manifold air flow rate. As only three model parameters are required, the calibration effort is minor. Instead of solving nonlinear equations to obtain the oxygen concentration from dissociation reactions, a simple estimation method used the estimated number of moles in the burned zone. The model was validated using engine data and show that the model can predict emissions with high accuracy as they vary with load, start of injection, fuel rail pressure and exhaust gas recirculation rate. As there are few, relatively simple algorithms involved, this model can easily be implemented online. It also has potential to be used in the control of both exhaust after-treatment and the engine combustion process.

A control-oriented NOx emissions model for diesel engines

This paper presents a practical demonstration of Nonlinear Model Predictive Control (NMPC) applied to the variable valve timing system of a 1 liter gasoline direct injection turbocharged engine over a transient maneuver. The nonlinear dynamic model utilized in the NMPC controller is a Takagi-Sugeno Neuro-Fuzzy model. The control problem has been formulated as a two-input-two-output multivariable control system with intake valve phase and exhaust valve phase angles as the two manipulated variables and engine fuel consumption and engine out NOx emissions as the two controlled variables. Two implementation methods were evaluated on the engine. In the first method, the NMPC using a sequential quadratic programming algorithm executed on a PC which was connected to the engine control unit over a controller area network. In the second method, the NMPC using a quasi-newton based optimization algorithm was deployed to and executed on the engine control unit. Results show the potential for >10% improvement in NOx emissions compared to the original engine strategy.

Nonlinear Model Predictive Control of a Variable Valve Timing System in a Turbocharged Spark Ignition Engine

Improve Cylinder-to-Cylinder Consistancy and Reduce Cycle-to-Cycle Variations of a Diesel Engine Using Closed-loop Control of Fuel Path Input Variables

Zhijia Yang

Papers

Combustion Model Based Explanation of the P max and IMEP Coupling Phenomenon in Diesel Engine

A Predictive Model of P max and IMEP for Intra-Cycle Control

A control-oriented NOx emissions model for diesel engines

Nonlinear Model Predictive Control of a Variable Valve Timing System in a Turbocharged Spark Ignition Engine

Improve Cylinder-to-Cylinder Consistancy and Reduce Cycle-to-Cycle Variations of a Diesel Engine Using Closed-loop Control of Fuel Path Input Variables