Diesel Generator Set Research Articles

Experimental Investigation on Innovative Modification of Aqua Silencer

One of the major threats to the society and environment is considered asair pollution which causesill effects to the human beings as well as environment. The main contributor to the air pollution is gases releasing from automobiles like carbon dioxide, unburned hydrocarbons etc. In view of addressing this major contributor, paper focused on modification of conventional silencer by introducing redesigned Aqua silencer that minimizes generation of such polluting agent. Aqua silencer is mounted similar to conventional silencer with minor modifications to the exhaust pipe of the engine. In modified aqua silencer emission is controlled by theactivated charcoallayers. Environment harmful gases are absorbed efficiently within the silencer and keep automobile environment friendly. Aqua silencer also addresses the noise pollution concern as sound produced within water is less audible because of smallsprocketsin water molecules lower its amplitude and so lowers the sound level. Aqua silencer is designed and developed at Mechanical Engineering Department, Government Engineering College, Bhavnagar and experiments were carried out by mounting aqua silencer on very high load engine like Diesel generator set. Performance indicators are measured and compared with conventional silencer used in diesel generator. Opacity of carbon particles is reduced up to 32.7%. However, few barriers and challenges that have been identified in this article must be addressed carefully before aqua silencer employed by the automobile industry.

Sustainable and Economic Alternative for the Electric Supply of Isolated Communities in the Brazilian Off-Grid Systems

Roughly 99% of the demand for electricity in Brazil is supplied by a national interconnected grid. The remaining 1% is spread in several “isolated systems” of the Amazon region—mini-grids that rely on expensive diesel gensets due to high commodity and transportation costs. The isolated systems also have remote communities disconnected altogether from the mini-grids with inadequate health, education and leisure services. These communities are precariously supplied by small inefficient diesel gensets that run for a few hours per day. In this article, we propose a sustainable and economic alternative for the electric supply of the remote communities of isolated systems through a combination of photovoltaic solar generation and storage. The objective is to improve access to electricity with savings for the communities. The present paper outlines a public policy to meet this objective.

Метод повышения топливной экономичности дизель-генераторной установки тепловоза в условиях эксплуатации

Метод повышения топливной экономичности дизель-генераторной установки тепловоза в условиях эксплуатации

Benefits of forecasting and energy storage in isolated grids with large wind penetration – The case of Sao Vicente

For electric grids that rely primarily on liquid fuel based power generation for energy provision, e.g. one or more diesel gensets, measures to allow a larger fraction of intermittent sources can pay-off since the displaced is high cost diesel powered generation. This paper presents a case study of Sao Vicente, located in Cape Verde where a particularly high fraction of wind capacity of 5.950 MW (75% of the average demand) is installed, with diesel gensets forming the dispatchable source of power. This high penetration of intermittent power is managed through conservative forecasting and curtailments. Two potential approaches to reduce curtailments are examined in this paper: 1) an improved wind speed forecasting using a rolling horizon ARIMA model; and 2) energy storage. This case study shows that combining renewable energy forecasting and energy storage is a promising solution which enhances diesel fuel savings as well as enables the isolated grid to further increase the annual renewable energy penetration from the current 30.4% up to 38% while reducing grid unreliability. In general, since renewable energy forecasting ensures more accurate scheduling and energy storage absorbs scheduling error, this solution is applicable to any small size isolated power grid with large renewable energy penetration.

Development of The Structural and Functional Design of the Laboratory Bench for Experimental Research Diesel Generator Sets on Variable Speed

A diesel generator set working at variable speed to save fuel is studied. A description is provided of a laboratory bench for conducting experimental studies of a variable speed diesel generator set. Its component parts are described, and its technical characteristics are given.

Simulating ozone concentrations using precursor emission inventories in Delhi – National Capital Region of India

This study simulates ground level ozone concentrations in a heavily populated and polluted National Capital Region (NCR- Delhi) in India. Multi-sectoral emission inventories of ozone precursors are prepared at a high resolution of 4 × 4 km2 for the whole region covering the capital city of Delhi along with other surrounding towns and rural regions in NCR. Emission inventories show that transport sector accounts for 55% of the total NOx emissions, followed by power plants (23%) and diesel generator sets (7%). In NMVOC inventories, transport sector again accounts for 33%, followed by evaporative emissions released from solvent use and fuel handling activities (30%), and agricultural residue burning (28%). Refuse burning contributes to 73% of CO emissions mainly due to incomplete combustion, followed by agricultural residue burning (14%). These emissions are spatially and temporally distributed across the study domain and are fed into the WRF-CMAQ models to predict ozone concentrations for the year 2012. Model validations are carried out with the observed values at different monitoring stations in Delhi. The performance of the models over various metrics used for evaluation was found to be satisfactory. Summers and post-monsoon seasons were better simulated than monsoon and winter seasons. Simulations have shown higher concentrations of ozone formation during summers and lesser during winters and monsoon seasons, mainly due to varying solar radiation affecting photo-chemical activities. Ozone concentrations are observed lower at those locations where NOx emissions are higher, and concentrations increase close to the boundary of study domain when compared to the center of Delhi city. Downwind regions to Delhi are influenced by the ozone formed due to plume of precursor emissions released from Delhi. Considering significant background contributions, regional scale controls are required for reducing ozone in NCR.

Experimental investigation of hydrogen addition in the intake air of compressed ignition engines running on biodiesel blend

This study investigates the effects on the performance of a diesel generator set at constant electric power of 2.43 kW (approximately 60% nominal engine load condition) and rotation at 3600 rpm operating with a 7% biodiesel-diesel blend (B7) and being doped with hydrogen into the intake air. Hydrogen was injected continuously into the engine intake manifold at different mass concentrations of 2, 6, 8 and 10% of the total fuel mass (B7 + hydrogen) which represents energy fractions of 5, 15, 20 and 24% of total fuel energy. To this, a small L-shaped tube installed at the center of the pipe was used. It is anticipated that the intake air fluctuations at that location, due to opening and closing the intake valve, allows a rapid mixture of hydrogen and air. Due to the addition of hydrogen the total amount of energy in the fuel (B7 + hydrogen) introduced into the engine was increased, so that the engine speed tends to increase, but this was prevented by the governor of the fuel injection pump which decreases the amount of B7 injected until the working frequency of the generator was 60 Hz. The test results showed a reduction in the specific fuel consumption as a function of the increase of hydrogen concentrations. Likewise, CO2, CO and HC emissions decreased proportionately as the hydrogen concentration was increased. On the other hand, the emissions of nitrogen oxides (NOx) increased due to the increase in the average temperature inside the cylinder. There was also an increase in the peak pressure and in the heat release rate inside the cylinder, since B7 ignition delay was reduced due to the increase in hydrogen content.

Design of reactive power regulator of synchronous generators by considering grid impedance angle for characteristic index objectives

Effects of low reactance to resistance ratio in distribution networks are widely studied but little work dealing with the tuning of voltage and reactive power regulators of small synchronous generators has been reported. This study endeavours the design of a proportional integral controller for the reactive power regulator to fulfil the characteristic index (CI) objectives, which are based on the step-response characteristics. Two small-signal models of the reactive power regulator have been developed from the well-known k-parameter model and they are validated. Apart from offline tuning of the regulator, these models can be used to assess system robustness and stability. In addition to the analytical approach, the same regulator is tuned optimally by means of multiple simulations. Proposed objective functions rely on the CIs tracked during the sequence of runs, whereas the traditional cost functions are formulated on the basis of the integral of an error. This difference makes them suitable for the cases where the entire step-response data series are unavailable. The performances of differently tuned regulators are compared considering a test system including a 100 kW Diesel Generator Set equipped with a brushless exciter.

Enhanced Performance of Isolated Wind-Diesel (IWD) Hybrid System feeding Heavy Load under various Operating Conditions

Objectives: To check /validate the stiffness of IW-D Hybrid System by putting heavy load of 150 hp at various loading conditions. And, to implement the remedies to the ill-conditions/operating conditions like frequency runaway and varying wind speed and to study the effect of these conditions on overall system as well as on heavy load. Further, to improve system performance, a suitable controller is to be incorporated with pitch angle control system. Method/Statistical Analysis: The electromechanical dynamics of various large electrical machines are represented by their full order models. The models of synchronous machine (7th order) of diesel genset, SEIG (5th order) and heavy load (5th order) are simulated to obtain power and voltage dynamics. The system dynamics consist of higher order differential equations, which are solved by converting into simpler algebraic equations related to current and voltage that are solved in short time by using phasor simulation in MATLAB/Simulink environment. Findings: The hybrid power systems are becoming popular because of greater efficiency and balance of energy supply. Due to many advantages like ruggedness, inexpensiveness and requirement of less maintenance in contrast to other electrical machines, heavy load like 3-ϕ squirrel cage induction motor that shares a major part of the total electrical portion on any power system. From the exhaustive study of, it is found that very few authors have worked on such system and the performance of the heavy load is either not considered of if taken into account it is not considered in detail. In this paper, an IW-D Hybrid Power System feeding heavy load is considered to analyze/ check the stiffness of IW-D Hybrid System. Few ill-conditions like frequency runaway and varying wind speed affects the system functioning and have considerable impact on the heavy load is reported in few papers but its remedy is not implemented or if given, the ill effect of these problems on the heavy load is not considered which needs great attention. Therefore, the solutions of above problems are mentioned in this work. Application/Improvement: The dynamic performance of modified IW-D Hybrid System has been validated and checked in context with ruggedness by putting heavy load of 150 hp at normal and overload condition. The dynamic behavior of IW-D System as well as heavy load has been improved for frequency runaway. Further, a PI controller including pitch servo is implemented to control the output of SEIG driven by wind turbine in case of varying wind speed, which improves the dynamic performance of the system.

Investigating the implications of a new-build hybrid power system for Roll-on/Roll-off cargo ships from a sustainability perspective – A life cycle assessment case study

Marine transport has been essential for international trade. Concern for its environmental impact was growing among regulators, classification societies, ship operators, ship owners, and other stakeholders. By applying life cycle assessment, this article aimed to assess the impact of a new-build hybrid system (i.e. an electric power system which incorporated lithium ion batteries, photovoltaic systems and cold-ironing) designed for Roll-on/Roll-off cargo ships. The study was carried out based on a bottom-up integrated system approach using the optimised operational profile and background information for manufacturing processes, mass breakdown and end of life management plans. Resources such as metallic and non-metallic materials and energy required for manufacture, operation, maintenance, dismantling and scrap handling were estimated. During operation, 1.76×108kg of marine diesel oil was burned, releasing carbon monoxide, carbon dioxide, particulate matter, hydrocarbons, nitrogen oxides and sulphur dioxide which ranged 5–8 orders of magnitude. The operation of diesel gensets was the primary cause of impact categories that were relevant to particulate matter or respiratory inorganic health issues, photochemical ozone creation, eutrophication, acidification, global warming and human toxicity. Disposing metallic scrap was accountable for the most significant impact category, ecotoxicity potential. The environmental benefits of the hybrid power system in most impact categories were verified in comparison with a conventional power system onboard cargo ships. The estimated results for individual impact categories were verified using scenario analysis. The study concluded that the life cycle of a new-build hybrid power system would result in significant impact on the environment, human beings and natural reserves, and therefore proper management of such a system was imperative.

Online measurement of torsional stiffness and fault analysis for flexible coupling under working condition

In this paper, a method of measuring the relative torsional angles of the flexible coupling under working condition was developed. A double-encoder measurement system was proposed to get the torsional angles. The torsional angles were divided into “constant torsional angle” and “alternating torsional angle”. The measured results were analyzed further, which were applied to a series of flexible couplings. Firstly, the torsional stiffness of D-type flexible coupling was obtained according to the relationship between torques and torsional angles. The proposed method overcomes the difficulty that the angular displacements of flexible coupling cannot be measured online under operating condition. The feasibility and accuracy of the method developed in this study was verified by comparing stiffness curve with unloading curve obtained from static torsional experiment and values from factory inspection report. Furthermore, in view of the tear fault of A-type flexible coupling in a diesel generator set, the maximum alternating torsional angles of A-type, B-type, and C-type flexible couplings were measured under working condition, then safety margins were obtained for the diesel generator set. According to the safety margins of the three kinds of couplings, C-type flexible coupling is chosen to replace A-type, which provided the basis for type selection of flexible coupling. Finally, the method developed in this study would also be applied to the operation monitoring and fault diagnosis of flexible coupling online.

Chemical characteristics of PM2.5–0.3 and PM0.3 and consequence of a dust storm episode at an urban site in Lebanon

Located on the eastern side of the Mediterranean Basin at the intersection of air masses circulating between three continents, the agglomeration of Beirut, capital of Lebanon is an important investigating area for air pollution and more studies are needed to elucidate the composition of the smallest particles classified as carcinogenic to humans. PM2.5–0.3 and PM0.3 samples were collected during the spring-summer period in an urban background site of Beirut, after a dust storm episode occurred, and their chemical composition was determined. Our findings showed that components formed by gas to particle conversion (SO42− and NH4+) and related to combustion processes are mainly found in the PM0.3 fraction. Typical crustal (Ca2+, Fe, Ti, Mg2+), sea-salt (Na+, Cl−, Mg2+, Sr) species, and NO3− are mainly associated with the PM2.5–0.3 fraction. We have also evidenced that the dust episode which occurred in Lebanon in May 2011 originated from the Iraqian and Syrian deserts, which are the least studied, and had a direct influence on the composition of PM2.5–0.3 during the beginning of the first sampling period, and then an indirect and persistent influence by the re-suspension of deposited dust particles. Moreover, PAHs concentrations were much higher in PM0.3 than in PM2.5–0.3 and their composition appeared influenced by diesel (buses, trucks and generator sets) and gasoline (private cars) emissions.

Integrating compressed air energy storage with a diesel engine for electricity generation in isolated areas

This paper reports an integrated system consisting of a diesel genset and a Compressed Air Energy Storage (CAES) unit for power supply to isolated end-users in remote areas. The integration is through three parts: direct-driven piston-compression, external air turbine-driven supercharging, and flue gas waste recovery for super-heating. The performance of the integrated system is compared to a single diesel unit and a dual-diesel unit with a capacity of electricity supply to a village of 100 households in the UK. It is found the fuel consumption of the integrated system is only 50% of the single-diesel unit and 77% of the dual-diesel unit. The addition of the CAES unit not only provides a shift to electrical energy demand, but also produces more electricity due to the recovery of waste heat.

A uniform power station of a transport unit with electric propulsion based on a diesel generator of varying rotation frequency

Electric propulsion systems have been recently used very often in various transport units. Traction electric motors can be powered, along with other consumers, from a uniform power station (UPS) of a selfsupporting unit. The application of a UPS promotes reliability and simplifies maintenance of the self-supporting unit’s electric system as the number of components of the latter is reduced. As a rule, a UPS is constructed on the basis of diesel generator sets (DGSs) of constant rotation frequency. The cost effectiveness of an electric station can be improved with the use of DGSs of varying rotation frequency. In this case, fuel economy is achieved by generating optimal shaft rotation frequency of the internal combustion engine, corresponding to the lowest brake-specific fuel consumption. The list of Russian and foreign published works dedicated to this topic is rather short, especially concerning research on the dynamic mode of work, the development of a mathematical model for the unit, and creation of a control system for a UPS with a DGS of varying rotation frequency. This article addresses the above issues, contains mathematical and simulation models of a self-supporting unit’s UPS with a DGS of varying rotation frequency, and shows the results of modeling.

Evaluation of Medium Speed Diesel generator sets and energy storage technologies as alternatives for reducing fuel consumption and exhaust emissions in electric propulsion systems for PSVs

The use of electric propulsion systems in PSVs in Brazil has recently increased, leading to be the standard for most support vessels. In those ships, the common arrangement uses high speed Diesel generator sets for power generation and induction motors driving propellers, reporting significant reductions in the fuel consumption and exhaust emissions compared with mechanically propelled PSVs. However, further abatements in these parameters could be achieved by implementing other technologies for power production. In this work, the use of medium- speed Diesel generator sets and energy storage technologies in electrically propelled PSVs is evaluated. For the above, the fuel consumption, exhaust emissions, mass, volume and acquisition costs of four arrangements are estimated and compared. Two of the arrangements are equipped with medium-speed Diesel generator sets, two with energy storage units and one with high-speed Diesel generator sets. Energy storage appears as interesting alternative for decreasing fuel consumption and emissions by optimal loading of Diesel engines. Medium speed generators also showed reductions in fuel consumption, but highest emissions. The arrangements with high-speed generators presented the lowest mass, volume and acquisition costs.

The research progress of the medium voltage DC integrated power system in China

With the constant development of modern marine technologies, the vessel energy now can be distributed through an Integrated Power System, which is known as the third vessel power revolution. In this paper, the technical features of the first and second generation integrated power system are introduced. Next, based on the present domestic technical status, the research progress of the quasi second generation medium voltage DC integrated power system in China is presented, with the corresponding difficulties and problems analyzed, including the system model, electrical-magnetic transient simulation, the connected op-erator between the gas turbine generator set and the diesel generator set, the system steady analysis, and system layered protection. Finally, the solutions are proposed, which indicates that the development are re-quired on the medium voltage DC breaker, system energy storage, system safe operation, multi-time scale, and multi object system energy regulation.

Power Quality Improvement of PMSG-Based DG Set Feeding Three-Phase Loads

This paper presents power quality improvement of a permanent-magnet-synchronous-generator-based diesel generator (DG) set feeding three-phase loads using a static compensator (STATCOM). A three-leg voltage-source converter (VSC) with a capacitor on the dc link is used as a STATCOM. The reference source currents for the system are estimated using an Adaline-based control algorithm. A pulsewidth modulation current controller is used for generation of gating pulses of insulated-gate bipolar transistors of the three-leg VSC of the STATCOM. The STATCOM is able to provide voltage control, harmonics elimination, power factor improvement, load balancing, and load compensation. The performance of the system is experimentally tested on various types of loads under steady-state and dynamic conditions. A three-phase induction motor with variable-frequency drive is used as a prototype of diesel engine with the speed regulation. Therefore, the DG set is run at constant speed so that the frequency of supply remains constant irrespective of loading condition.

Demonstration of the First European SOFC APU on a Heavy Duty Truck

Within the EU-FCH JU funded project DESTA the partners AVL, Eberspächer, Topsoe Fuel Cell, Volvo and Forschungszentrum Jülich are collaborating since January 2012 to demonstrate the first European Solid Oxide Fuel Cell Auxiliary Power Unit (SOFC APU) on a heavy duty truck. The APU is used to provide the truck with electrical energy during vehicle standstill to power comfort functions like A/C, TV, refrigerator & PCs. To facilitate these functionalities typically, the main diesel engine is idled which causes significant emissions and operating cost. The APU is used with conventional diesel fuel and provides about 3 kW of electrical power at 30% electrical efficiency. To enable the usage of conventional fuel, SOFC technology is used.Main advantage of the SOFC stack technology is the use and operation with synthesis gas generated out of conventional fuels. Hence DESTA SOFC APU systems can be operated with conventional road Diesel fuel. Within the APU system, the Diesel fuel is reformed to a hydrogen and carbon monoxide containing synthesis gas. The SOFC technology allows the conversion of this hydrogen and also carbon monoxide with oxygen of the air directly into electricity. This creates a significant benefit in comparison to other fuel cell technologies like PEM or HT PEM. This process also allows significantly higher electrical efficiencies than conventional solutions like a diesel gen-set. Additionally the fuel cell APU is extremely silent and doesn’t emit other harmful emissions like NOx, THC or PM.

Sistemas Integrados de Potencia en Buques Offshore: Control, tendencias y retos

The offshore vessels require a high precision speed control and dynamic positioning. Adverse weather conditions and/or rough waves give rise to high disturbances that must be rejected by the control system to keep the vessel position in the area or station where the vessel operation is being executed. Other requirements related to the safety, reliability and robustness must be obviously ensured. Since more than a decade the power system of this kind of vessels is based on a diesel-electric power plant where the propellers and thruster units are controlled by electrical drives. In this power system the required electrical energy/power is generated through diesel gensets, and distributed to the propulsion drives (and to the rest of vessel utility loads) through a power grid. In this work the most commonly used integrated power system architecture is first introduced thus identifying the control functions and their interdependencies. Some trends and new power system topologies to improve the energy efficiency are then also presented and described. The emergence of new solutions based on DC grids allows the diesel gensets to operate at variable speed and makes the integration of the energy storage systems or even some renewable energy systems easier. However, they present some technical and design challenges in order to ensure a stable and robust solution by design. One of them is related to the stability analysis of the DC grid when multiple nonlinear constant power loads (negative impedance) are connected and thus interacting on the same DC bus.

Hybrid marine power plants model validation with strategic loading

Abstract: Recent advances in Energy Storage Devices (ESD) technology has enabled new supervisory control strategies for power generation and distribution on hybrid marine power plants, supported by new class society regulations. A marine hybrid power plant is characterized by the presence of both a traditional power producer, i.e. diesel Generator-set (genset), and an ESD, i.e. batteries. In this paper, two models to estimate strategic loading average fuel consumption were derived and compared. The first model is a higher fidelity dynamic model formulated as a hybrid system, in which the simplified engine dynamics is included, accounting for both continuous-time and discrete-time dynamics representing gensets and ESD as well as the switching. The second model consists of a steady state weighted average, where transient effects are not taken into account. Both models disregard thermal effects on the engine as well as assume that the engine fuel consumption is only a function of the engine speed and power output. The motivation to derive two models is due to the fact that the static model, due to its steady state nature, can estimate the expected weighted average fuel consumption very fast, being a new tool on the hybrid power plant operation optimization. The hybrid model, due to its dynamic nature and accounting for continuous-time and discrete-time dynamics, takes a longer time to simulate the system, which is unfeasible when it comes to real time operations. It is thus required to estimate the errors in the weighted average model due to the simplifications, asserting for which cases it is valid. The results show that the steady state model gives the exact solution in cases where dynamic effects are not relevant. It is a good approximation for systems where the switching period is much higher than the engine time constant, and the load dynamics time constant. The switching frequency is directly related to the ESD energy storage capacity, thus, systems with a large ESD will be better approximated by the steady state model than systems with relatively small ESD.