Electrical Auxiliary System Research Articles

Experimental investigation of generating superheated steam using a parabolic dish with a cylindrical cavity receiver: A case study

Abstract This study uses solar energy to convert steam from a saturated to a superheated state using a solar steam superheater system. This collector system comprised a parabolic dish with a cylindrical cavity. The parabolic dish is of 2 m diameter and 0.83 m focal distance, covered with a reflective surface made of 1,283 rectangular pieces of mirrors, each of 3.5 cm × 4 cm that were fixed in place with glue type (FnTai). The receiver is a stainless-steel cylindrical cavity having a diameter of 17 cm and a length of 25 cm. A helical copper coil with a diameter of 10 mm and a length of 6 m was inserted inside the cylindrical cavity. The experimental work utilized saturated steam produced separately from an auxiliary electric boiler system, which was made along with other system components. A 0.011 kg/s of saturated steam at a temperature of 112°C enters the copper coil and is heated by the solar radiation reflected by the parabolic dish onto the receiver. As a result, the temperature of the steam is increased to 169.5°C at the receiver outlet. It was found that the collector efficiency is 55.6%. In addition, the convection and radiation heat losses are 12.14 and 10.98%, respectively. Also, the heat losses of (spillage, reflection, and conduction) were estimated to be 21.18%. The mass flow rate and pressure of the saturated steam from the boiler and entering the receiver affected the superheated steam production process. The process of superheating the steam, coupled with the subsequent improvement in thermal performance, indicates an increased efficiency of the collector. This is achieved by boosting the generation of useful heat and mitigating heat losses.

The Application of a Solar–Air-Source Heat Pump Dual-Supply Heating System in a High-Cold Area in China

Solar energy is the most available renewable resource and has great potential for various applications. Solar heat pumps are limited when operating alone due to weather and the unstable and intermittent nature of solar energy. The idea of combining a solar collector with an air-source heat pump (ASHP) is proposed to solve the problems. Taking solar energy and air energy as the heat source of the system can improve the heat collection efficiency and heating performance coefficient of the dual-supply heating system in realizing the efficient and stable operation of the whole unit. This study investigated the application of a solar–air-source heat pump (S/AS-HP) dual-supply heating system for a residential building in Lhasa and compared the winter work performance and economic benefits of three different heating forms: solar–air-source heat pump, air-source heat pump, and solar–electric auxiliary heating systems. A simulation model was established and analyzed using the measurement data. The results show that during the heating period, the temperature of the primary side water supply is stable at about 60 °C, and the total operating hours of the solar collector period accounted for 26.9% of the total hours, of which 23.16% were independent operating hours. The average COPsys of the solar–air-source heat pump is 4.21, which greatly improves work performance compared with other systems, and the annual cost is the lowest among the three forms for the same service life at 41,824.6 CNY, saving 9.6% and 35.1% per year compared with the air-source heat pump system and the solar–electric auxiliary heating system. Considering conditions in alpine regions, S/AS-HP systems are the optimal heating solution for single buildings.

Soft-Switching Smart Transformer Design and Application for Photovoltaic Integrated Smart City Power Distribution

Smart city power distributions have become promising technologies to meet the demand for energy in developed countries. However, increase in smart grids causes several power quality problems on the smart grid, in particular, current and voltage harmonic distortions, sudden voltage sag and swells, fault current, and isolation deterioration. Smart transformers are potential solutions to improve the power quality on the electric grid. They present energy efficiency, ensure grid reliability and power flow control, voltage regulation, bidirectional power flow, fault current limiting, harmonic blocking, and galvanic isolation. Therefore, this paper offers an optimal selection of a three-stage (AC-DC-DC-AC) smart transformer model and power control strategy for solar PV power plant integrated smart grids. The topology of the rectifier, isolated bidirectional converter, and inverter has soft-switching features. This enables low conduction loss, low electromagnetic interference (EMI), high efficiency, achievable zero-voltage switching for converters, and zero-current switching for electrical auxiliary systems. Operation strategies of the proposed ST, PWM control, voltage, and current control between converters, including a medium-voltage (MV) high-frequency transformer to realize a 10 kVA, 450 Vdc to 220 Vdc, or 220 Vac ST, are presented. Significantly, the ST prototype achieves 96.7% conversion efficiency thanks to its control strategy, even under unstable power generation conditions from the solar PV plant. Experimental results obtained on the 344 Vac 10.4 A load current validates the dv/dt rate 6.8 kV/us. The dynamic and experimental results of the proposed bidirectional smart transformer demonstrate the success in preventing power quality problems for photovoltaic integrated smart city power distribution.

Operation optimization of auxiliary electric boiler system in HTR-PM nuclear power plant

Electric boilers (EBs) are the backup steam source for the auxiliary steam system of high-temperature gas-cooled reactor nuclear power plants. When the plant is in normal operations, the EB is always in hot standby status. However, the current hot standby operation strategy has problems of slow response, high power consumption, and long operation time. To solve these problems, this study focuses on the optimization of hot standby operations for the EB system. First, mathematical models of an electrode immersion EB and its accompanying deaerator were established. Then, a control simulation platform of the EB system was developed in MATLAB/Simulink implementing the established mathematical models and corresponding control systems. Finally, two optimization strategies for the EB hot standby operation were proposed, followed by dynamic simulations of the EB system transient from hot standby to normal operations. The results indicate that the proposed optimization strategies can significantly speed up the transient response of the EB system from hot standby to normal operations and reduce the power consumption in hot standby operations, improving the dynamic performance and economy of the system.

Theoretical study of motor brake power with permanent throttle and electromagnetic valve

The article shows that in comparison with hydraulic and electric auxiliary braking systems, the engine brake has a simpler design, several times lower weight and cost. It can be installed in the exhaust pipe of almost any car, and its application gives a significant socio-economic effect. A mathematical model has been developed for the theoretical study of the power of motor brakes with a constant choke and with an electro-magnetic valve. A theoretical study of the ZMZ-406 engine with a motor brake with a constant choke and an electromagnetic valve has been carried out. The analysis of the research results showed that a motor brake with an electromagnetic valve provides a greater braking power of the internal combustion engine, and, consequently, a better vehicle braking efficiency. Keywords: research, car, engine brake, throttle, solenoid valve, power

Study on saving energy for electric auxiliary systems of electric bus

ABSTRACT Since Electric Auxiliary Systems (EAS) accounts for a large proportion of electric bus energy consumption, in order to reduce EAS energy consumption and improve bus driving range, the working principles of EAS have been studied. The number of passengers, bus interior and exterior temperature can have great influence on EAS energy consumption, it is important to dynamically manage EAS working status according to the changes of bus driving conditions for saving energy, then an integrated control method for EAS is proposed for better meeting the real demands of EAS. The proposed method takes EAS as a whole and can manage EAS working status mainly according to the changes of bus passengers. For verifying the effectiveness of the proposed method, an electric bus model including EAS has been built and simulated by co-simulation in different platforms. Compared with common control method, the experimental simulation results shows that EAS energy consumption can be effectively reduced by dynamically managing EAS working status according to the changes of bus driving conditions, energy consumption proportion of each subsystem in EAS also has been discussed. The proposed method gives new way for saving EAS energy and has great application value for electric buses.

Design and dispatch optimization of a solid-oxide fuel cell assembly for unconventional oil and gas production

This paper presents design and dispatch optimization models of a solid-oxide fuel cell (SOFC) assembly for unconventional oil and gas production. Fuel cells are galvanic cells which electrochemically convert hydrocarbon-based fuels to electricity. The Geothermic Fuel Cell (GFC) concept involves utilizing heat from fuel cells during electricity generation to provide thermal energy required to pyrolyze kerogen into a mixture of oil, hydrocarbon gas and carbon-rich shale coke. We formulate a continuous, non-convex nonlinear program (NLP) in A Mathematical Programming Language (AMPL) to analyze the techno-economic characteristics of the GFC system. The problem is separated into a design model $$({{\mathcal {D}}})$$ and a dispatch model $$({{\mathcal {O}}})$$ . The GFC design problem determines the size and configuration of a single heater well. Specifically, we optimize the heater length and number of SOFC stacks in each assembly such that the maximum volume of oil shale is heated per well. Using the resulting design from $$({{\mathcal {D}}})$$ , the dispatch model $$({{\mathcal {O}}})$$ determines daily GFC operating conditions through variation in electric current, fuel utilization, and stoics of excess air. We optimize the system operating costs and the combined-heat-and-power efficiency, subject to geology heating demands, auxiliary component electric power demands and GFC system performance characteristics. Solutions to the design and dispatch problems are obtained using the IPOPT and KNITRO solvers. A case study shows that the optimal well-head cost of oil and gas produced using the GFC technology is about $39 bbl $$^{-1}$$ , which is comparable to that from other unconventional crude oil extraction techniques. The optimal dispatch strategy results in a maximum heating efficiency of 43% and a combined-heat-and-power efficiency of 79%. The Geothermic Fuel Cell’s performance is better than current in situ upgrading technologies that rely on electricity supplied from the grid at generation-and-transmission efficiencies near 33%.

Analysis of Anti-disoperation Interlocking Design for Marine Auxiliary Electric Propulsion Equipment

Take the marine auxiliary electric propulsion system as an example, to analysis the reasons that the crew disoperation in concrete operation. Put forward two sets anti interlocking design based on the time relay circuit which installed between auxiliary pushing plate and auxiliary pushing control signal, to eliminate disoperation in the implementation. Even to eliminate adverse effect about error identification caused by signal deranged, and uncoordinated movements caused by dislocation. Ensure the safe and reliable of auxiliary electric propulsion equipment. Electrical interlocking designed and installed doesn’t influence the original technical performances or functions of the auxiliary electric propulsion equipment. The simple circuit and reliable function improves the safety of auxiliary pushing device.

Replacing traditional materials with polymeric materials in solar thermosiphon systems – Case study on pros and cons based on a total cost accounting approach

The pros and cons of replacing traditional materials with polymeric materials in solar thermosiphon systems were analysed by adopting a total cost accounting approach. In terms of climatic and environmental performance, polymeric materials reveal better key figures than traditional ones like metals. In terms of present value total cost of energy, taking into account functional capability, end user investment cost, O&M cost, reliability and climatic cost, the results suggest that this may also be true when comparing a polymeric based thermosiphon system with a high efficient thermosiphon system of conventional materials for DHW production in the southern Europe regions.When present values for total energy cost are assessed for the total DHW systems including both the solar heating system and the auxiliary electric heating system, the difference in energy cost between the polymeric and the traditional systems is markedly reduced. The main reason for the difference in results can be related to the difference in thermal performance between the two systems. It can be concluded that the choice of auxiliary heating source is of utmost importance for the economical competiveness of systems and that electric heating may not be the best choice.

Packed Bed Chemical Looping Platform: Design and Operation of 30 kWth Pilot Unit

Chemical looping combustion is a novel flameless combustion, where the conventional combustion is divided into reducer and oxidizer with assistance of the oxygen carrier. Due to its instinctive CO2 separation, high efficient and environmental-friendly property, chemical looping combustion attains more concerns. Large-scale experimental unit is a vital to chemical looping combustion, especially the commercial development. The reactor configuration of the worldwide pilot units are fluidized bed or moving bed, and the pilot unit with packed bed has not been reported. In this study, the pilot scale chemical looping packed bed unit with a nominal thermal capacity of 30kWth is designed on the basis of previous laboratory scale investigation. The pilot unit includes four parts, which is gas system, reaction system, tail gas treatment and gas analysis system, and auxiliary electrical system. The pilot packed bed reactor is made from 310s stainless steel tube with a 0.089 m o.d., a 0.079 m i.d., and 2.0 m height. A K-type thermocouple with 13 measurement points is located at the center of the packed bed reactor to obtain the axial temperature profile. The packed bed chemical looping platform is constructed to demonstrate the feasibility of generating high purity hydrogen from syngas derived from biomass wastes with on-site carbon capture. Two testing runs were presented using 5mm × 4-6mm cylindrical oxygen carriers comprising of 50wt % iron oxide (Fe2O3). The pure CO and the mixture of CO and H2 with a flow of 15 SLPM are the fuels of the two tests. The first test resulted in a full CO conversion with a 25.0% conversion of the oxygen carriers during reduction, the production of 3.82mol hydrogen with an average purity of 98.0%, and the maximum temperature rise is 219K during air combustion. The second test leaded to a full fuel conversion with a 35.7% conversion of the oxygen carriers during reduction, the production of 4.67mol hydrogen with an average purity of 98.0%, and the maximum temperature rise is 290K during air combustion. The two testing runs, the first operation of packed bed chemical looping pilot unit, supported syngas-based chemical looping application for hydrogen and power co-generation with in suit carbon capture and also demonstrated the design of the 30kWth pilot chemical looping platform with packed bed reactor.

English

A Thermal power plant consist of various cycles and subsystems like air & flue gas cycle, main steam cycle , feed water & condensate water cycle , fuel & ash cycle, Equipment cooling water (ECW), auxiliary cooling water (ACW) system, Compressed air system ,Electrical auxiliary power & lighting system, HVAC system etc . In India , most thermal power plants employing sub critical technology are able to work only at 30 - 40 percent efficiency . The remaining 60 - 70 %is lost during generation, transmission and distribution out of which the predominant loss is in the form of heat . This paper demonstrates the major energy saving potential areas and methods to improve the overall efficiency of a thermal power plant .

Research in Power Module Test Platform of HXD2 Electric Locomotive

This paper introduces the electrical principle and structure of auxiliary electrical system of HXD2 electric locomotive. It presents the main design ideas of the power module test platform and focuses on the design of the power cabinet and the control cabinet of the power module test platform. The core design of the control cabinet is the peripheral circuit and hardware design which is based on DSP. The high power experiments prove the reliability of design.

Research on High-Rise Building Integrated Automatic Tracking Solar Water Heater

In order to solve the problem that high-rise users can't install traditional solar water heater for limited area and the problem that the utilization rate of panel position fixed solar energy is low, this paper proposed a new design of high-rise building integration solar water heater, which can make solar water heater integrate with high-rise building, and has the function of tracking sunlight automatically in real time, raising the utilization ratio of solar energy, and prolonging sunshine time. In addition, the auxiliary electrical heating system can be intelligently started or closed by setting the temperature sensor in the storage water tank of water heater. Humidity sensors automatically control the stretch of panel according to humidity, which can effectively protect the panel and prolong its life, and preferably realized green and energy-saving architectural concept.

The Design of Solar Heating System for Oil Field Duty Room

Based on the natural environment of Gansu YuMen oilfield in china, aiming at the winter heating requirements for oil field duty room, using the solar heating system that make solar energy storage and auxiliary electric heating, selection of flat plate collector, tacking double working medium for heat exchange indirectly, use the antifreeze liquid as the hot working medium, use the water as the energy storage and heating medium. According to the room temperature and medium temperature, intelligent control system adjust and control the double medium circulation loop, automatic regulating the intermittent work time for auxiliary electric heating system, the problem of antifreeze and sand prevention be solved effectively in the extreme temperatures. Compared to the electric heater heating, it can realize energy saving and environmental protection, the energy saving effect more than 46%, having remarkable economic and social benefits.

IEC61850 Based Modeling and Implementation for Management of Electrical Substation Auxiliary System

IEC61850 is the current international standard for the communications networks and systems in substations, and it allows seamless communications within and among electrical substations. Based on the discussion of IEC61850 standard, this paper provides details on how to use IEC61850 modeling methodology to model substation auxiliary system. The model considers the functions and characteristics of substation auxiliary system and it meets the IEC61850's modeling requirements.This paper also discusses the implementation of IEC61850 based management software for substation auxiliary system.

Parabolic trough concentrators for hot water generation: Comparison of the levelized cost of production

With the objective of demonstrating the technical and economic viabilities of a hybrid solar energy system applied to hot water generation, a simulation of a parabolic trough power plant with an auxiliary electrical heater system is presented. This article reports the procedure to obtain the characteristic equation of the useful heat value when N parabolic troughs are operated in series; the equation takes into account the heat loss through the pipes and the use of a heat exchanger. Additionally, this work reports a theoretical case study of a hybrid system that supplies hot water via solar energy and an auxiliary electrical system. The solar fraction and the global efficiency of the hybrid solar power plant are calculated. Using the results from the simulation, a cost analysis of the hybrid solar power plant was done where the levelized cost of thermal power generated is obtained; this in turn shows that the levelized cost of a conventional electrical heater system is one and a half times more than that of the hybrid system.

Thermal Power Plant Electrical Network Flow Calculations Based on AnySimu Platform

In this paper, the Guodian Zhishen development of DCS as a platform, set up a thermal power plant 1000MW unit auxiliary power electrical system diagram AnySimu platform for simulation support system, and electrical network designed according to the principle of power flow calculation algorithm to calculate theeach node voltage, phase, and thus the load operator. After the simulation, verify the validity of the algorithm.

Investigation of High Frequency AC Power Distribution Benefits for the Automobile Auxiliary Electrical System

This paper aims to indicate the advantages and any drawbacks of high frequency alternating current (HFAC) power for vehicle auxiliary electrical systems. Generally, benefits of HFAC include efficient power distribution and transformation, space and weight saving and load galvanic isolation. In addition, HFAC bus topologies are distributed to the point of use, lending the system to easy fault detection. The paper is structured as follows: first, the main findings of the most relevant automotive HFAC studies are outlined. Next, an HFAC architecture is proposed which is compared to the existing 14V and proposed 42V centralised DC networks in terms of power distribution efficiency and wiring harness weight saving. For this analysis, the case study of a medium-sized passenger vehicle is considered, and a group of intermittent and continuous auxiliary loads with a cumulative power of 2.8kW. The calculations over a 1200s drive cycle show that the power distribution efficiency for a 50kHz, 100V AC power bus increases by 90 per cent and 80 per cent compared to 14V and 42V DC topologies, respectively, and the wiring copper weight drops significantly by 70 per cent and 30 per cent, respectively.

Hybrid Electric Drive for DDG-51 Class Destroyers

The first of the Arleigh Burke class destroyers is nearing its mid-life. This class of ships was designed during the late 1970s through the 1980s to meet the threats that were prevalent at that time. Since entering service in 1991, these ships have shown themselves to be extremely versatile and the class now consists of nearly 60 ships in service. Their combat systems have been continually upgraded and adapted to meet the new threats the United States faces today. However, in order to keep these platforms viable throughout the first half of the 21st century, their operating costs must be reduced. Manpower, maintenance, and fuel are three of the top operating cost drivers. Most surface combatants spend very little of their underway time operating at full speed or even close to that. Over 1/3 of their underway time is spent at 12 knots and under. This is less than half of their maximum speed and only a fraction of the maximum power owing to the cubic speed–power relationship. Although the existing mechanical drive system is reasonably efficient, the main gas turbines are extremely inefficient at these very low power levels. A shaft-mounted auxiliary electric propulsion system (EPS) can take advantage of excess capacity in the ship service generators to reduce the main engine operating hours. Enabling bi-directional power flow from this auxiliary electric drive will provide additional generation capacity for ship service loads at a modest additional cost. It also provides a “cross-connect” capability from one shaft to the other. This paper will explore one prospect for reducing the operating cost of the DDG-51 class of ships by installing an auxiliary EPS that would powered by the ship service electrical plant. This additional system would serve to reduce both underway fuel usage as well as maintenance on the gas turbine main engines by reducing the number of operating hours on each engine. We will examine the technology trade-offs in this ongoing study.

Electric propulsion for future carriers

The two new aircraft carriers due to be built by BAE Systems and Thales will have electrical propulsion with all power generated by gas turbines. The new aircraft carriers will thus join a new generation of electrically propelled Royal Navy warships, a generation which includes the Daring Class Type 45 anti-air warfare destroyers, which are the first warships in the world to incorporate fully integrated electric propulsion and power. It is thought likely that power will be generated by four of the new Roll-Royce MT-30 marine gas turbines. The decision to adopt electric propulsion for the future carriers accords with a general Royal Navy marine engineering policy whose aim is to build all-gas turbine ships with electrical propulsion, auxiliary and weapon systems.