Although significant progress has been made in relation to air source heat pump (ASHP) modeling, it is difficult to reflect the actual dynamic characteristics of the start-up process by a completely theoretical model, and a regression model cannot reflect the energy efficiency differences between systems intuitively. A semi-theoretical model for fixed speed ASHP which considers the modifications of

In this paper, the simultaneous production of power and freshwater by the integration of a gas turbine (GT), a supercritical carbon dioxide (S-CO2) cycle, an organic Rankine cycle (ORC) and a reverse osmosis (RO) desalination unit is proposed. The S-CO2 and the ORC are bottoming cycles that recover the waste heat from the exhaust gases of the GT. A RO seawater desalination unit has been added to this

Precise determination of the chemical equilibrium state is important for electrochemical and thermodynamic modeling of a molten carbonate fuel cell (MCFC). One method for determining the equilibrium state of a MCFC with internal reforming is to compute the total Gibbs free energy of the system (G) and minimize it by adjusting the molar amounts of each substance. Multi-dimensional optimization algorithms

In this paper, a comparative investigation on the supercritical carbon dioxide power cycle for waste heat recovery of gas turbine is carried out. Four categories and six cycles are chosen to represent typical layout of supercritical carbon dioxide power cycle based on thorough literature reviews. The selected cycles are optimized and analyzed based on the results of single- and multi-objective optimization

The aim of this study is to model and highlight the capabilities of the cogeneration of electricity and water using a contemporary configuration employing a multi-effect desalination plant and a reverse osmosis plant integrated with a concentrated solar power plant using parabolic trough collectors, working on the basic principle of the Rankine cycle. Environmental data was collected at the selected

The rapidly growing photovoltaic power generation (PPG) instigates stochastic volatility of electricity supply that may compromise the power grid’s stability and increase the grid imbalance cost. Therefore, accurate predictions of long-term PPG are of essential importance for the capacity deployment, plan improvement, consumption enhancement, and grid balance in systems with high penetration levels

The increasing ambition of climate targets creates a major role for hydrogen especially in achieving carbon-neutrality in sectors presently difficult to decarbonise. This work examines to what extent the currently carbon-intensive hydrogen production in Europe could be replaced by water electrolysis using electricity from renewable energy resources (RES) such as solar photovoltaic, onshore/offshore

Since the energy and environment issues, adsorption refrigeration technology has raised the great attention and interest by worldwide researchers and scholars, because it can efficiently use low-grade heat and its refrigerants are natural. Among the numerous working pairs of adsorption refrigeration, silica gel-water is most suitable for massive applications in solar and waste heat field, as its developed

A novel heat pump with a hybrid condenser combined with flat plate micro-channel heat pipe (MCHP) plus thermoelectric generator (TEG) and Fresnel photovoltaic (FPV) evaporator is proposed and investigated in this paper. In the previous work, the TEG is inserted between the concentrated PV and absorber plate in the evaporator. Although the TEG can convert the heat stored on PV into electricity, it hinders

A series system with multi-stage reverse electrodialysis reactor (REDR) can harvest salinity gradient energy (SGE) from working fluids as much as possible to treat organic wastewater. In this paper, the series system simulated with a single REDR system to degrade azo dye wastewater was investigated experimentally. The results showed that the series system could not only degrade azo dye wastewater effectively

In order to optimize the geometry of the M−like flow field, numerical simulations were performed by virtue of the fuel cell module in ANSYS® FLUENT® software package. Two geometrical parameters of the M−like channel, namely height and width of elliptic obstacle, were considered. Based on the exhausted numerical results in the study, it has been found that the M−like channel exhibits more uniform and

In this paper, thermodynamic and thermoeconomic analysis as well as genetic algorithm optimization of two combined cycles, a gas turbine-organic Rankine cycle (GT-ORC) and a gas turbine-Kalina cycle (GT-KAL) are carried out. The novelty of this study is that the cycles are adapted to an actual solid waste power plant to generate additional power from the exhaust gas. Thus, the power generation capacity

Urban wastewater is a valuable source of clean energy available for both building conditioning and hot sanitary water production, thus reducing primary energy demand and greenhouse gas emissions. In the present study, the integration of a highly efficient solar-assisted fully off-the-grid water-source heat pump (SHP) with a sequencing batch biofilter granular reactor (SBBGR) is tested on a pilot scale

The premixed H2/air combustion with various propane blended ratios in two size stepped combustors with porous medium is experimentally and numerically studied. In order to improve the energy efficiency and power output of the micro thermophotovoltaic (TPV) system with InGaAsSb PV cells, the effects of step length and porous medium length in the chamber are comprehensively investigated. Moreover, the

This paper proposes a combined cooling, heating, and power system integrated with full-spectrum hybrid solar energy device containing molecular solar thermal system and solar water heating system to improve solar energy utilization efficiency. This system comprehensively integrates solar energy, fuel chemical energy and waste heat energy based on methanol decomposition to optimize energy utilization

Accurate and efficient parameter estimation of the photovoltaic (PV) models is considered a dispensable process to simulate the PV systems. Therefore, many meta-heuristic algorithms have been recently proposed, but the parameters obtained are not as accurate and reliable as is desired, particularly when the PV models have a significant number of unknown parameters. Therefore, in this paper, a modified

The hemp market is fast growing due to demand for cannabidiol, nutraceutical and hemp fiber products. This work demonstrates the economical advantage of biomass gasification application to indoor hemp production. Gasifiers provide electrical energy, heat and biochar: these are highly valuable products for indoor growers where lights and thermal management are key costs of the business. Energy produced

This paper proposed a cryogenic power generation system composed of Rankine cycles and direct expansion cycle, aiming at the efficient utilization of flue gas waste heat and liquefied natural gas (LNG) cold energy. Both the sensible heat and latent heat of the humid flue gas are recovered to meet the heat demand of a typical LNG terminal. Performance analysis was conducted to reveal the potential improvement

The aim of this paper is to study a new modular micro-scale trigeneration system based on a rotary Fresnel collector, named “SunDial”, under a restricted design space. This system is based on the integration of an organic Rankine cycle with a vapor compression heat pump using miniaturized turbomachinery. Four layouts areoed to maximize the energy supply according to different heat management strategies

The forest and energy sectors are heavily affected by the urgent need for global climate gas emission reductions. To fully understand the implications of a transition to a low carbon society, it is important to analyse the interactions between these sectors. We herein present a coupled/integrated modelling approach that integrates a Nordic Forest Sector Model (NFSM) and a North European energy sector

The synthesis of multiperiod heat exchanger networks (HEN) is a well-studied topic in heat integration. Several methods for identifying heat exchanger network designs that are able to feasibly operate under multiple conditions have been presented. Multiperiod models are certainly a notable form of achieving such resilient designs. In work and heat integration, however, solutions presented so far are

In this paper, a bladeless rotational piezoelectric energy harvester using a tipping bucket is proposed to overcome the energy collection problem from liquid with ultra-low flow and ultra-low head. It is typically difficult to collect ultra-low flow liquid energy using the blade rotation of hydro turbines. To overcome this problem, a magnetic wheel fixed to the tipping bucket is introduced in the proposed

As the global trend towards transition to a “hydrogen society” continues to gain momentum, a lot of studies on alternative hydrogen (H2) production methods are on the rise. Among them, methylcyclohexane (MCH) dehydrogenation in a membrane reactor (MR) is reported here as one possible candidate, affording its enhanced H2 yield and a compact design. In this study, techno-economic analysis and carbon

Combined heat and power plants are important assets in the current energy infrastructure, as they play an essential role in ensuring the security of energy supply. Therefore, they must have low downtime. Currently, preventive maintenance is the most popular maintenance strategy for combined heat and power plants. The preventive maintenance includes performing regular, scheduled maintenance checks and

Dual-pressure organic Rankine cycle (DPORC) is a technology with great potential to solve energy problems. This paper performs constructal thermodynamic optimization (CTO) for the DPORC based on a combination of constructal theory and finite-time thermodynamics. The tube outside diameters of the heat exchangers, such as high- and low-temperature evaporators (HTE and LTE) and condenser, and the volume

As a novel energy-conservative ventilation system for buildings, a dedicated outdoor air system (DOAS) assisted by a vacuum-based membrane dehumidifier is proposed, and its energy performance is investigated via detailed energy simulations. The vacuum-based membrane dehumidifier dries the air by an isothermal process, which is difficult to realize in conventional dehumidification systems. The proposed

Ammonia is an example of a zero-carbon fuel of high interest for implementation in gas turbine technologies. Preliminary analyses showed that a basic humidified ammonia-hydrogen Brayton cycle can produce total plant efficiencies of ~34%. However, further improvements are required to make these units competitive to current fossil-based plants whose efficiencies are above 80%. Thus, this work seeks to

The advantageous performance on energy conversion of triangular prisms in Flow Induced Motion Energy Conversion (FIMEC) system has been verified by previous researches. In this paper, the magnetic flux density (B) was introduced into the mathematical model to analyze damping (ctotal), active power (Pharn) and energy conversion efficiency (ηharn) in FIMEC system. A physical model was established to

For combined-cycle power plants, the two most dominant steam condenser cooling options are the wet-cooling tower and the air-cooled (dry) systems. The wet cooling system is commonly installed on plants located in areas with available water sources, while the dry system is typically preferred in areas where water is scarce. However, owing to the increasing regulations on water conservation, water usage

Toward the accurate electrical and mechanical modulations of the piezoelectric harvester, this paper presents a unified electromechanical-coupled voltage equation and a damping determination method. A single differential equation for the voltage is obtained that accommodates mechanical and electrical physics for which the exact transient solution is presented. In addition, the fully coupled relationship

Renewable energy technologies around the world have become a priority today and among them, hydropower plants have the largest share. The most significant problem with small hydropower plants is the high cost of commercial turbines. The most economical way to generate small-scale energy is to use a pump as turbine (PAT) due to the cheapness and availability of the pump. In water distribution networks

In this study, a three-dimensional multi-phase model is developed to numerically investigate the effect of gas diffusion layer spatial variation properties on water management and performance of proton exchange membrane fuel cells. The research mainly focuses on the influence of non-uniform porosity distribution in through-plane direction under different operating pressure and anode inlet humidity

Stirling engines (SE) offer good part load performance and high heat sink temperatures which make it a suitable candidate to serve as a prime mover in micro-combined cooling, heating and power (μ-CCHP) applications. In this study, a novel μ-CCHP configuration hybridising a SE prime mover with an ORC to utilise the waste heat from the SE to produce additional power is proposed. Additional waste heat

Lithium-ion battery systems are becoming a major component in numerous applications. The thermal behaviour of cells should be monitored for many reasons. In this paper, the investigation of the energy balance for lithium-ion battery system is described. The electrothermal model allows to describe heat generation and heat dissipation processes in all components of a battery pack (BP). Moreover, this

To develop the energy-efficient and flexible waste heat recovery process for cruise ship application, a novel combined system with transcritical CO2 Rankine cycle and ejector refrigeration cycle (ETCRC) is presented. The proposed system driven by main engine exhaust gas can be selectively operated in a specific mode with adjustable capacities of heating, cooling and power to satisfy shipboard demands

Improving the overall efficiency of a present power system has significant importance as much as developing renewable energy systems. Because, there are many constructed power systems, which damages the environment by releasing a considerable amount of heat to the environment without use. Therefore, in the present paper, probable single, dual and triple system configurations were assessed in terms