Energy Utilization Factor Research Articles

Experımental investigation of heat pump driven humidification-dehumidification desalination system for water desalination and space conditioning

This work presents an experimental investigation of the performance of a HDH system operated by heat pump. The novel heat pump system provides the necessary heating for the humidifier and cooling for the dehumidifier of the HDH system. The proposed integrated unit is capable of producing freshwater as well as cooling effect for space conditioning through water heated or cooled heat exchange units. Influence of various operating parameters such as feed water flowrate, feed water temperature and chilled water flowrate on the general assessment metrics, including gain output ratio (GOR), recovery ratio (RR), coefficient of performance (COP), energy utilization factor (EUF), Specific electrical energy consumption (SEEC) and productivity are evaluated. The cost of freshwater production from the proposed desalination unit is estimated. Results showed that the integrated system is capable of attaining maximum GOR of 4.07, RR of 4.86%, COP of 4.85, EUF of 3.04, and productivity of 287.8 L/day. The minimum SEEC of the system was found to be 160.16 kWhr per cubic meter of freshwater. The system is also capable of providing cooling load of 3.07 kW while producing the needed desalinated water. The estimated price of freshwater production varied from 10.68 US$ to 20.39 US$ per cubic meter.

Effective Routing Protocol And Analysing Various Attacks In The Manet Network

Mobile Ad-hoc Network is the self-configuring structure less network for transmitting the information from one node to another node because of the independent node direction. During the information transmission in the network one of the main challenges is to maintain the intermediate node information for making the effective transmission. In addition the intermediate person may be hacking the information by performing the Wormhole and Black hole attacks. So, in this paper proposes an effective Neighboring Relationship based Clustering protocol. The protocol analyzes the neighboring relationship between the transmitted node information protocols. Each similar node information is grouped into the cluster. At the time cluster head and neighboring node topology has been updated continuously for avoiding the middle man attacks like, wormhole and black hole. Further the energy consumption is managed by applying the Fireflies algorithm based Energy efficient routing protocol with efficient manner. Then the efficiency of the system is analyzed using the experimental results like, packet delivery ratio, energy utilization factor and percentage of attack free routing efficiency.

Natural gas based trigeneration system proposal to an ice cream factory: An energetic and economic assessment

This work presents an energy and financial analysis of an energy trigeneration system, in which electricity, steam and chilled water are produced simultaneously using natural gas as source of input. The system consists of an internal combustion engine, a domestic heat recovery unit, a LiBr/H2O absorption chiller to produce chilled water and a recovery boiler to produce steam. In this system, the exhaust gases produced by the engine are used to drive an absorption chiller through a heat exchanger and can also drive a recovery boiler. According to the final results, and considering total engine load, the overall system of trigeneration presented an energy utilization factor of 74%, with average electricity, cooling and heating production of 214.1 kW, 35.7 kW and 162.1 kW, respectively. A case study based on the energy demands of an ice cream industry is presented in this article for the financial analysis of the system. In order to determine the best configuration for the company, the one that presented a higher financial return, three scenarios were developed for the application of cogeneration or trigeneration in the company. They were analyzed on the financial methodology of calculation of return on investment, using as parameters the net present value (NPV), the internal rate of return (IRR) and the simple payback, based on an interest rate of 6.4% and a project period of 10 years. The first two scenarios created were not economically viable, presenting a negative NPV. However, scenario 3 presented good financial return result, presenting a NPV of $ 269,390.40, a 26.32% IRR and a 3.4 year simple payback, making it the best financial scenario for the company. The results of this work indicate that the configuration proposed in scenario 3 provides several useful results with high efficiency and a good financial return for the company.

A hybrid system for power, desalination, and cooling using concentrated photovoltaic/thermal collector

ABSTRACT In this work, a mathematical modeling of a hybrid system using concentrated photovoltaic thermal (CPVT) collector integrated with combined desalination and cooling plant is presented. The hybrid system performance is analyzed throughout the day during summer (21/06/2018) and winter solstice (22/12/2018) in the geographical location of Vellore, India. The effect of meteorological variables on system performances such as hot water temperature, PV efficiency, desalination yield, chilled air temperature, and plant energy utilization factor (EUF) are analyzed. The overall plant performance is also compared with conventional solar flat plate collector driven desalination and cooling plant. The developed model is validated with experimental work. The highest EUF of CPVT driven plant in summer and winter solstice are 0.29 and 0.31, respectively. The comparative study reveals that use of CPVT collector to operate desalination and cooling plant improves the plant EUF. The highest increase in plant EUF of 49% is attained at a hot water temperature of 47.5 °C. Further, economical evaluation of CPVT operated desalination and cooling plant is carried out to estimate the unit cost of fresh water and payback period. Based on energy cost and interest rate in Vellore, India, the unit cost of fresh water and payback period are estimated to be ₹ 10/L and 6.5 years, respectively.

Multisource Switched Capacitor Based Boost Multilevel Inverter for Photovoltaic-Based Systems

In this paper, a multisource switched capacitor based boost multilevel inverter is proposed. The proposed topology features less number of components, high gain, self-charging capability of capacitors, reduced size of filter components. The modes of operation of the proposed converter and design guidelines of converter components are discussed. A comprehensive comparative study of the proposed converter topology with the topologies in the literature is given. Analytical expression for capacitor energy utilization (CEU) factor for the proposed topology is derived and the feasibility of the proposed converter with respect to CEU for the designed power rating is verified. The analytical performance of the proposed converter topology is verified through simulation studies. The common mode voltage and leakage current in the proposed topology are analyzed. Experimental prototype of the proposed converter topology with two sources and two capacitors for power rating of 500 W is developed and tested with resistive, inductive, and nonlinear loads. The experimental and simulated results are in close agreement with the analytical steady-state performance of the proposed converter.

DEVELOPMENT OF WIND ENERGY COMPLEX AUTOMATION SYSTEM

Wind power is one of the three main renewable energy sources, along with solar and hydropower, which are widely used to produce electricity worldwide. As an energy resource, wind is widespread and can provide electricity to much of the world, but it is both intermittent and unpredictable, making it difficult to rely on wind power alone. However, when used in combination with other types of production or in combination with energy storage, wind can make a valuable contribution to the global energy balance. Over the past few decades, wind power has emerged in a number of countries as a separate energy sector that has successfully competed with conventional energy. Attention is paid to wind power plants (WT) as part of distribution and transmission networks. In this regard, an urgent scientific and technical task is the efficient use of wind potential, which is not only to improve aerodynamic characteristics WT, but also to increase productivity WT as a whole. This article presents the type of wind turbines, among the possible applications and very promising is the wind turbine Bolotov (WRTB), which by its technical characteristics surpasses the traditional propeller and other installations using wind energy in the production of electrical energy. The increase (WEUF - wind energy utilization factor) in all modes of operation WT by improving various methods of automatic control is relevant, and the proposed work is devoted to this issue.

Energy and exergy analysis of cold and power production from the geothermal reservoir of Torre Alfina

Geothermal power plants can provide clean and renewable energy and can be proposed as integrated units for simultaneous production of cooling and power. This paper presents a cascade arrangement of an organic Rankine cycle (ORC) and a water/lithium bromide (LiBr) absorption chiller (ABS). Starting from a literature reference layout which is taken as benchmark, some improvements are proposed at system level.To assess the performance of the system, a thermodynamic model is developed in EES and the energy and exergy balance is calculated. The proposed system is re-evaluated with reference to resource conditions corresponding to a planned power plant in central Italy, Torre Alfina (TA). A sensitivity analysis is performed in order to investigate the operating range of the plant and the possibility of adapting its design to the requirements of the customers. Under optimized conditions, the TA Case (targeted on a 5 MW power output) showed an energy utilization factor (EUF) of 46.2% and an exergy efficiency of 27.7%, neglecting the brine reinjection loss. The highest exergy destructions occur in the ORC economizer (8.6%), in the ABS generator (6.3%) and absorber (5.5%). The good resource conditions in TA case drive the design optimization to production of power rather than cold.

Parametric Study of Combined Cooling and Power (CCP) Plant Integrated with Parabolic Trough Solar Collectors (PTSCs)

This study presents a detailed energy analysis of a Combined Cooling and Power (CCP) plant operated by Parabolic Trough Solar Collectors (PTSCs). The integrated cycles; Vapor Absorption Refrigeration Cycle (VARC) and Organic Rankine Cycle (ORC) are used to produce cooling and power, respectively. Six organic working fluids, namely, R113, R141b, R123, R245fa, R142b, and isobutane were selected for ORC, while LiBr-H2O solution used in VARC. Four key energetic parameters, useful heat gain, work output, cooling rate, and energy utilization factor (EUF) were examined during varying direct normal irradiance (DNI). A parametric study was carried out in three modes of operation, power only, combined power and cooling and cooling only under the limits of DNI from 0.6 kW/m2to 0.88 kW/m2recorded on the yearly-average basis in two cities of Pakistan, Lahore, and Quetta respectively. Results enunciated that R113 given the highest thermal efficiency of 17.12%, while isobutane gave the least thermal efficiency of 7.88%, hence R113 was chosen as organic working fluid for further study. The maximumEUF was found in the cooling mode of operation which increased from 63.95% to 66.79% at 0.6 kW/m2 and 0.88 kW/m2 respectively. During the combined cooling and power mode, maximum cooling rate, power output, and EUF were 3456 kW, 822.5 kW, and 41.34% respectively at 0.88 kW/m2.

Assessment of energy potential of agricultural residues

The paper deals with the existing approaches to the interpretation of the potential of bioenergy resources. The most widespread practices of differentiation of potentials by foreign and domestic scientists are considered and the increasing role of environmental factors is emphasized. The definition of theoretical, technical, energy, economic and sustainable potentials is given. The paper suggests not to allocate sustainable or environmental potential since there is no information available for accurate calculation in absolute or relative terms. But at the same time, the constraints from the viewpoint of sustainable development at all stages of the calculation have to be taken into account. Agricultural residues are divided into primary ones, that is, those that are generated directly during the harvest, and secondary – generated during the crop processing at the enterprises. The paper establishes that the magnitude of the energy potential is mainly influenced by factors such as competition between the use of residues for energy purposes and the needs of livestock; the possibility of depletion of organic nutrients in the soil by removing the residue of straw from farmland. Practice shows that unused residues in a large enough volume are often burned in fields, which is officially banned in Ukraine and is harmful to the environment and soil. Energy utilization ratios, waste coefficient for each crop type, coefficient of technical availability of waste, energy utilization factor and factor of conversion into conditional fuels are examined and based on them the energy potential of primary and secondary plant wastes are calculated. A significant part is the cereal straw, which remains largely unused, and the corn waste. Due to its energy potential, the magnitude of which exceeds the similar potential of the EU countries, and its accessibility, it has the potential to significantly influence the energy situation in the country.

Bagasse saving and water recovery in cogeneration system using superheated steam dryer

The cogeneration system in sugar factory uses bagasse with high moisture content as the fuel for the boiler, which results in low boiler efficiency. The system also produces superheated steam, which is extracted from the turbine, and mixed with cooling water to produce saturated steam required by the evaporation system. The potential use superheated steam to reduce bagasse moisture content is ignored in the standard practice of the sugar factory. In this article, an investigation is made into the improvement of the cogeneration system by using superheated steam dryer to reduce the moisture content of bagasse. Mathematical models are developed for the typical system without superheated steam dryer and the improved system with superheated steam dryer. They are then used to compare the performances of both systems. It is found that, under the condition that the required steam flow rate for the evaporation process and the power output are the same, the improved system requires less bagasse consumption, and has larger energy utilization factor. In addition, water that would be lost with flue gases in the typical system is recovered in the improved system.

Issues of an optimization of measurements location in redundant measurements systems of an energy conversion process – A case study

The measurements system of an energy conversion process is treated as a redundant if it fulfills the conditions for the application of the advanced data validation and reconciliation. At the design stage of such a system, the problem of the number of redundant measurements as well as their location appears from the point of view of the optimization method. In this case, the solved superior optimization problem is the problem of the combinatorial optimization. These tasks are difficult from a computational point of view. For contemporary computers, this may become impossible for larger-scale tasks because the computing time of the corresponding algorithm is an exponential function from the problem dimension to the solution. Example calculations for the redundant measurement system of a selected gas-and-steam CHP unit have been carried out. As an objective function of the combinatorial optimization task, the relative uncertainty of the energy utilization factor in the CHP unit was assumed. To evaluate the redundant measurements system as a whole the relative information entropy – Kullback-Leibler divergence has been accepted. The optimization calculations for all elements of space of states, i.e. for all possible location configurations of the redundant measurements in the thermal system of CHP unit have been performed. Discussion of received results due to the possibility of limiting the dimensionality of the solved optimization combinatorial task and consequently the significant reduction of the numerical calculation time has been carried out. Analyses of a suitability of proposed methods for limiting the number of sets of redundant measurements configurations in the optimization calculations have been performed.

State of charge and state of power management among the energy storage systems by the fuzzy tuned dynamic exponent and the dynamic PI controller

Abstract This paper develops the small signal modelling of the storage systems. In order to attain an equalized energy utilisation factor among the high energy density based storage elements, a dynamic exponent based decentralized state of charge (SoC) management scheme is integrated. Moreover, due to the low relative inertia of the microgrid, the system may undergo a power imbalance condition with the varying generation and demand. Thus, to improve the system inertia a high power dense storage element is incorporated into the system. A fuzzy-based decentralized state of power management scheme (SoP) is proposed in the study. To ensure the robustness of the proposed SoC and SoP management scheme, the microgrid is extensively tested under the dynamically varying generation and load scenarios. The system stability of the proposed approach is further cross-verified through the Nyquist stability criterion.

Economic Assessments of Hydrogen Production Processes Based on Natural Gas Reforming with Carbon Capture

Hydrogen is a promising energy carrier for future low carbon economy as fuel or chemical for various industrial applications (e.g. heat and power, petro-chemical, metallurgy etc.) as well as for transport sector. In order to decarbonise the energy sector as well as the transportation sector, the fossil fuels need to be efficiently converted to hydrogen and the resulted CO2 to be captured and then used / stored. The Carbon Capture, Utilisation and Storage (CCUS) technologies are promising options of efficiently combating climate change (by significantly reducing the greenhouse gas emissions) as well as continuing of using the fossil fuels. This paper is assessing the key updated technical and economical performances of hydrogen production based on natural gas reforming with and without carbon capture. As illustrative examples, conventional steam reforming and autothermal reforming (using both oxygen and air) of natural gas were evaluated. The CO2 capture technology was based on pre-combustion capture configuration using gas-liquid absorption. As illustrative cases, Methyl-DiEthanol-Amine (MDEA) as a chemical solvent and SelexolTM as a physical solvent were assessed for their performances. The evaluated hydrogen production concepts have a capacity of 100,000 Nm3/h (corresponding to 300 MWth based on lower heating value) with a purity higher than 99.95 % (vol.). The paper presents in details the evaluated hydrogen production concepts based on natural gas reforming, modelling and simulation aspects, model validation, mass and energy integration issues as well as proposing an integrated methodology for quantification of key economic aspects. As the results show, the conventional steam reforming has higher energy utilisation factor (about 5 net percentage points) than the autothermal reforming cases. The carbon capture rate is about 65 - 70 % for the conventional steam reforming considered as an illustrative case. The economic indicators show better performances for conventional steam reforming in comparison to autothermal reforming in term of specific capital investment cost (about 12 - 24 % lower), operational and maintenance costs (about 7 % lower), hydrogen costs (about 5 - 10 % lower). Physical absorption is more energy and cost effective than chemical absorption as pre-combustion capture method.

Novel cooling augmented cogeneration cycle

In the existing Goswami cooling cogeneration, the fluid is expanded from high pressure to low pressure and produced cooling at the exit of turbine. But in the proposed method, the fluid is expanded from the high pressure to intermediate pressure, condensed and throttled from the intermediate pressure to low pressure. The novel cooling cogeneration proved its potential by generating extra cooling and compensating its power penalty compared to other cooling cogenerations. The work is mainly focused on thermodynamic modeling, simulation, analysis and development of best process conditions. It has been observed that the cooling is 20 times high and power is 25% of the conventional cogeneration. On overall, the total production and its energy conversion is much better than the existing cogeneration. The cycle energy utilization factor (ENUF) of proposed cogeneration is 4.5 times greater than the regular cogeneration.

Investigation of performance and emission characteristics of waste cooking oil as biodiesel in a diesel engine

Biodiesel is one of the most popular prospective alternative fuels and can be obtained from a variety of sources. Waste frying oil is one such source along with the various raw vegetable oils. However, some specific technical treatments are required to improve certain fuel properties such as viscosity and calorific value of the biodiesel being obtained from waste cooking oil methyl ester (WCOME). Various treatments are applied depending on the source and therefore the composition of the cooking oil. This research investigated the performance of WCOME as an alternative biofuel in a four-stroke direct injection diesel engine. An 8-mode test was undertaken with diesel fuel and five WCOME blends. The best compromise blend in terms of performance and emissions was identified. Results showed that energy utilization factors of the blends were similar within the range of the operational parameters (speed, load and WCOME content). Increasing biodiesel content produced slightly more smoke and NOx for a great majority of test points, while the CO and THC emissions were lower.

Comparison of bead shape, microstructure and mechanical properties of fiber laser beam welding of 2 mm thick plates of Ti-6Al-4V alloy

Fiber laser beam welding experiments are carried out on 2 mm thick plates of Ti-6Al-4V alloy at various welding conditions. A specially designed workpiece fixture with shielding gas delivery system is fabricated and effectiveness of shielding gas is confirmed by energy dispersive X-ray spectroscopy analysis. Two different types of bead cross-sections i.e. T-shaped and nearly X-shaped beads are observed at different line energies. After experiments, width and area of fusion zone and size of heat affected zone are measured and further analyzed. The microstructural studies at different locations in heat affected zone and also in fusion zone are carried out with optical microscope and their morphologies are compared at different welding conditions using field emission scanning electron microscope. The porosities are observed in both T and X-shaped weld beads at different line energies. However, their sizes are in acceptable range as per BS EN:4678 standard. The maximum microhardness is found in fusion zone due to the presence of large amount of α′ martensite. The line energy utilization factor is higher for T-shaped bead than X-shaped bead. The tensile strength of T-shaped bead is lower than X-shaped bead due to higher non-uniformity in the distribution of plastic strain. The experimental results show that T-shaped welding conditions are favorable while considering full penetration in keyhole mode, narrower weld width and lesser heat affected zone.

Thermodynamic Performance Assessment of a Novel Micro-CCHP System Based on a Low Temperature PEMFC Power Unit and a Half-Effect Li/Br Absorption Chiller

The aim of this work has been to evaluate the energetic feasibility and the performances of a novel residential micro-Combined Cooling, Heating and Power (CCHP) system, based on low temperature proton exchange membrane fuel cell (PEMFC) power unit and half effect lithium bromide absorption chiller. This integrated system has been designed to produce both electric, thermal and cooling power by recovering heat from the fuel cell power unit cooling system. The analysis has been conducted by using numerical simulations: the PEMFC power unit and the absorption chiller have been modeled by means of one-dimensional and thermochemical models, respectively, and by means of available experimental and literature reference data, has been performed the validation. The performance parameters such as: the energy utilization factor (EUF), the exergy utilization factor (ExUF) and the trigeneration primary energy saving (TPES), have been used to analyzed the performances of the system. The numerical results showed a good performance in terms of energy and ExUF, in the whole operating field of the trigeneration system. Furthermore, the highest ExUF values are obtained for the minimum evaporator temperature (4 °C) and minimum condenser temperature (27 °C) of the absorption chiller. The calculated values of TPES for the CCHP mode, ranges from −0.07 to 0.19, thus, the system has good performance in a wide operating range, but the better performance can be achieved at lower loads.

Performance investigation of Kalina cooling cogeneration cycles

The power and cooling demands are increasing drastically with increase in living stands and population. Kalina cycle system (KCS) is a power cycle and vapor absorption refrigeration (VAR) is a refrigeration cycle operating with zeotropic mixture. In this work, the common features of KCS and VAR are identified and developed a new Kalina cooling cogeneration cycle (KCCC) to generate combined power and cooling from a single plant configuration. The total output from cogeneration is compared with the total generation from the individual plants (KCS and VAR) at low temperature heat source (155−180 °C). To justify the merit of proposed configuration, thermodynamic simulation has been conducted through critical investigation applied to flexible KCCC under varying operating conditions viz. strong solution concentration, source temperature, separator vapor concentration and dephlegmator effectiveness. The generated results are power, refrigeration, combined power and cooling, cycle energy utilization factor (ENUF) and plant ENUF. The power to total output ratio in KCCC once through cycle is considered as a reference to the other cooling cogenerations for the comparison. The highest cycle ENUF (0.39) is resulted with KCCC once through cycle. KCCC split cycle is not recommended because of its lower efficiency (0.18) compared to the non-integrated efficiency (0.21).

Augmented desalination with cooling integration

Humidification–dehumidification (HDH) desalination works based on a water cycle principle and involves air humidification and condensation (dehumidification). The cooling of humid air with chilled water increases the desalination and results in cold air suitable for air conditioning process. The merits of the proposed HDH desalination and cooling are not analyzed and compared in the literature. Therefore, the performance results of HDH with normal water (current technology) and HDH with chilled water (proposed idea) are compared to highlight the merit of this cycle. The combined cycle for desalination and cooling has been solved thermodynamically with psychrometric properties. The results are validated with a laboratory experimental setup. The examined operational process conditions are hot water inlet temperature, efficiency of humidifier, and vapor absorption refrigerator's (VAR's) evaporator exit temperature. The focused results are desalination, cooling and energy utilization factor (EUF). The comparative study recommends the use of chilled water in the final stage. The two stage desalination with dehumidification by normal water in the first stage and chilled water in combined two stages improves the cycle EUF from 0.18 to 0.33. Out of 300 W of cooling generation, 100 W is used for dehumidification and the remaining 200 W is available for air conditioning process at 15 N⋅m3 h−1 of air.

Thermodynamic Investigation of Integrated Air Cycle Refrigeration Systems

An analysis of air cycle refrigeration (ACR) systems based on the first and second laws of thermodynamics has been carried out. Cooling the gas cooler outlet enhances the system efficiency, hence the use of integrated refrigeration systems (IRSs). The IRS consists of an ACR, an absorption chiller and a prime mover. The waste heat from the prime mover operates the absorption chiller, which provides additional cooling that is used to cool down the air exiting the gas cooler. LiBr-H2O and NH3-H2O are used as fluid pairs in absorption section. The prime mover can either be gas turbine or solid oxide fuel cell (SOFC). Results indicate that an IRS with NH3-H2O and two recuperators has a better first and second law efficiency compared to other considered systems. It is also concluded that the energy utilization factor and second law efficiency are higher for the system with SOFC as a prime mover.