Optimization Design Of System Research Articles

Ideas and Countermeasures for Optimum Design of Environmental Protection System Based on Ecological Security

Effective environmental protection system is an effective way to promote the coordination between economic and social development and resources and environment. Based on the combing analysis of the development process of China’s environmental management institutions, systematically expounds the process of continuous improvement and change of the environmental management system. Combined with the characteristics of China’s economy from the stage of rapid growth to the stage of high-quality development, the key problems at present are analysed. Focusing on the demand of future ecological civilization construction and sustainable development, while on the basis of elaborating ecological security systematically, and then this paper puts forward the idea of optimum design of environmental protection system based on ecological security. According to the actual task of economic structure adjustment and economic layout adjustment under the construction of national ecological security, this paper focuses on improving the function of ecological services, and puts forward the countermeasures for optimizing the environmental protection system in China and the basic means for effective implementation of the safeguard system.

Representative days selection for district energy system optimisation: a solar district heating system with seasonal storage

The design and operational optimisation of fourth generation district heating networks is a crucial step towards highly renewable energy systems of the future. In order to optimise such complex systems, a toolbox modesto (multi-objective district energy systems toolbox for optimisation) is being developed. Seasonal thermal energy storage is an essential technology to allow larger shares of renewable energy sources, yet large computational power is required for its representation in full-year operational optimisations, as a step towards district energy system optimal design. To decrease computational complexity, a technique with representative days able to include seasonal thermal energy storage systems is developed and validated. This methodology combines different part-solutions from literature, but also adds a novel aspect to safeguard the chronology of the optimisation problem. To validate the approach, the design optimisation of a fictitious solar district heating system with seasonal thermal energy storage is compared to different representative day optimisations in two steps. The operational optimisation is a linear optimisation problem, implemented using modesto; the design optimisation is built as a genetic algorithm, optimising the size of the storage and solar systems in the network. The validation exercise is done for the operational and for the design optimisation separately. This comparative study shows that modelling with representative days adequately mimics the behaviour for the presented case. Furthermore, a solution speed-up in the order of 10–30 times is shown for the representative optimisations with respect to the full year optimisation, in line with the reduction of the number of variables.

DESIGN AND OPERATING ASSESSMENT OF SOLAR PV UNDERGROUND WATER PUMPING SYSTEM IN UPPER EGYPT

This work presents a detailed approach to the optimum design, performance and economical assessment of a solar PV underground water pumping system using AC submersible pump and motor based on the proposed daily water demands for a farm allocated in remote area in Upper Egypt under the least solar radiation conditions during the winter season. The performance assessment after the PV pumping system installation was performed taking into consideration the insolation period, water flow rate, hydraulic power, PV electric output power, pump and pumping system efficiencies. The assessment results indicated that the insolation period extended to 6 hours from 9:00 to 15:00 where the PV current affected strongly by the variation of the solar radiation intensity and consequently the motor speed, while the voltage remained stable. The data revealed that the solar radiation has high correlation (R2=0.9618) with water flow rate due to the continuous changes in the current where the PV system gave average daily flow rate of 49.50m3/h that higher than the design flow rate of 48m3/h. Moreover, maximum hydraulic pump power was 7518.40 W (at noon) which is higher than the designed hydraulic power of 7394.5 W and this means that the pump efficiency was exceed the suggested efficiency of 75% during designing of the PV system. Generally, the average pump and PV pumping system efficiencies were 64.8 and 13.10%, respectively. High validation was proved through the assessment with the design aspects of the PV pumping system and good performance of the selected pump, motor and PV configuration. Ultimately, the PV pumping system was saved the annualized and pumping costs with 47.33 and 36.36%, respectively, comparing to the diesel-pumping system at the same well.

Optimal Design of a Distributed Energy System Using the Functional Interval Model That Allows Reduced Carbon Emissions in Guanzhong, a Rural Area of China

Nowadays, rural power supply in China plays an important role in restricting the economic development and improvement of residential living standards. In this study, an interval full-infinite programming rural energy model (IFIP-REM) was developed for supporting distributed energy system (DES) optimal design under uncertainties in rural areas. By affecting the upper and lower bounds of the interval by complex and variable external conditions, IFIP-REM could simulate the influence of external systems. To validate the model, a real case study of DES optimal design in Guanzhong, a rural area of China, was tested and aimed to minimize system cost and constraints of resources, energy supply reliability, and carbon emission mitigation. The data revealed generation of reasonable optimization schemes to obtain interval solutions of IFIP-REM. Compared to centralized energy system (CES), DES reduced electricity purchasing of the municipal grid by 47.5% and extended carbon emission of both upper and lower bounds to [17.13, 44.51] % and [12.42, 36.02] %, respectively. Overall, the proposed model could help managers make decisions of DES optimal design by coordinating conflicts among economic cost, system efficiency, and carbon emission mitigation.

Study on lightweight structural optimization design system for gantry machine tool

In order to improve the efficiency and effectiveness of the lightweight design of the gantry machine tool, a lightweight structural optimization design system for the gantry machine tool was constructed. Serialized gantry machine tools were parametrically modeled, and a load model with multiple operating conditions was established. A twice optimization design method integrating zero-order optimization, parameter rounding, and structural re-optimization was proposed. Using the proposed method, a lightweight structural optimization design system for gantry machine tool with parametric design, lightweight design, and other functions was developed. The developed gantry machine tool lightweight structural optimization design system was applied to complete the lightweight structural optimization design of gantry frame of a certain gantry machine tool, so the structural parameters of the gantry frame were optimized. Although the maximum stress and the maximum deformation of the gantry frame increases within the allowable range, the experimental comparison before and after the optimization shows that the mass of the whole gantry frame is reduced by 9.24%, which is beneficial to save the manufacturing cost. The research results show that the constructed lightweight structural optimization design system of the gantry machine tool has high engineering practicality.

Multiobjective optimization design of ultrahigh-head pump turbine runners with splitter blades

The traditional design method, design-experiment-design, is time consuming and difficult. In the present paper, an efficiency design system for pump-turbine runners, the multiobjective optimization design system, which includes 3D inverse design, Computational Fluid Dynamics (CFD), Design Of Experiment (DOE), Radial Basis Function (RBF) and Multi Objective Genetic Algorithm (MOGA), is presented and then applied to design a scaled ultrahigh-head pump turbine runner. First, the control parameters, blade loading and the splitter work ratio, and the runner efficiencies under pump and turbine mode were selected as input variables and optimization objectives respectively. Then the DOE was applied to select the sample runners, and the CFD was used to predict the efficiencies of the sample runners under different modes. The relationship between input variables and objectives was built by RBF based on CFD results. Finally, the MOGA was applied to generate and search the good overall performance runners according to the relationship built by RBF. The results indicate that: the pump mode efficiency of preferred runner is increases by 0.34% and the turbine mode efficiency by 2.07% compared to the initial runner. With the improvement of efficiency, the pressure and streamline distribution are improved obviously.

Optimization design of aeronautical hydraulic pipeline system based on non-probabilistic sensitivity analysis

This article investigates the design of constraint hoops in the aeronautical hydraulic pipeline system. Non-probabilistic sensitivity analysis is used to screen out the hoops which are insensitive to the maximum stress response, the maximum displacement response as well as the first-order natural frequency. The analysis result can give guidance to reduce the size and weight of the pipeline system. Based on the pretreatment analysis, the position coordinates of the remaining constraint hoops are further optimized. Comparison before and after optimization reveals that the dynamic performances of the pipeline system are significantly improved. This study indicates that the proposed method can provide an effective solution for the design of aeronautical hydraulic pipeline systems.

Determination of the ORC-RO system optimum parameters based on 4E analysis; Water–Energy-Environment nexus

This paper presents the concentration disposal index (CDI) concept extension for increasing the Water–Energy-Environmental nexus and reducing the environmental impacts of RO system brine. This non-dimensional index introduces the difference between the density of brine flow and raw water tank in recovery. This concept is utilized in main engine system of the ship. Different configurations of Organic Rankine Cycle (ORC) and working fluids are studied at the outlet of high temperature thermal source (280 °C), based on Energy analysis (1E), Exergy (2E), Economic (3E) and environmental impacts (4E) in order to produce desalinated water (4E+D). The output power from ORC is used as the driver of RO high pressure pump. Based on the waste heat in system, the sources are used for preheating of RO system pump inlet water. These sources are: Lubricating oil, air cooler and jacket cooler and ORC condenser. The key parameters in optimization are: (1) the ORC configuration choice, (2) the working fluid of Rankine cycle based on thermal source, (3) the RO system optimum design, (4) the membrane selection among the DOW company membranes, (5) the pinch and approach temperatures of the Waste Heat Recovery (WHR), (6) the reduction of environmental impacts of RO brines, (7) the selection of Energy Recovery Device (ERD). Determination of these parameters is done according to system optimization by genetic algorithm (GA). In order to consider the CDI function impact, once the system is considered with two objectives based on exergy efficiency of the entire cycle and the unit product cost (UPC) and then is considered by three objectives; the two mentioned ones and the CDI function. The results of these two optimizations indicate that, utilizing CDI reduces the ultimate concentration of the brine and increases the buoyancy force for faster mixture. In three-objective optimization, the ORC configuration is chosen with the recuperator, the R245ca working fluid, the two-stage RO system and the SW30XLE-400i membrane for both of stages.

Riding Comfort of an Electric Vehicle Based on the Coupling Affection of Mechanical Friction and Electric Regenerative Brake

In order to satisfy the braking comfort of electric vehicles, the braking performance and braking force distribution schemes are studied for the coupling braking system of mechanical friction and electric regenerative braking of electric vehicles. First, the performance of the coupling brake system was analyzed. Then the problem of braking force distribution is studied, and the logical distribution of braking force based on comfortness is proposed. The influence of braking strength and braking speed on the braking comfort of electric vehicles is fully considered. So the braking force is distributed between the two braking systems and between the front and rear axles to meet the comfort. The consistency of the two braking systems is achieved through multidisciplinary modeling, comprehensive simulation and system optimization design. And the electric vehicle model was established on the MATLAB, AMESim and ADAMS co-simulation platform, then the braking comfort and safety of the electric vehicles were simulated. The simulation results were in compliance with the ECE regulations. Finally, the braking efficiency of the series and parallel braking distribution strategies under gravel pavement is compared. The results show that the braking efficiency of the series braking distribution strategy is better. Through theoretical simulation and experimental tests, it is found that the braking force distribution strategy is feasible and effective. Electro-hydraulic brake system has good performance, paving the way for the industrialization of electric vehicles.

Performance Analysis and Multi-objective Optimization Design of Vehicle Electro-hydraulic Compound Steering System

Performance Analysis and Multi-objective Optimization Design of Vehicle Electro-hydraulic Compound Steering System

Experimental investigation of jetting effect on spudcan extraction from soft clay

The jack-up unit may suffer difficult extraction from soft clay attributed to the large embedment and suction. To ease spudcan extraction, the jetting technique is extensively adopted. The jetting effect on spudcan extraction is investigated with a series of model tests. Firstly, the effectiveness of top jetting is investigated, and it is found that the top jetting is not effective in reducing extraction resistance. Secondly, the efficiency of different jetting procedures are studied. It is revealed that jetting prior to extraction reduces the suction by increasing the excess pore pressure at spudcan base. And the jetting after extraction begins reduces the suction by filling the gap formed under the spudcan with jetting water and eliminating cavitation. Finally, tests with different jetting times, jetting rates, jetting pressures, and jetting nozzle locations and numbers are conducted. It is found that the effect of jetting time converges as it increases. The flow rate of jetting prior to extraction has little effect on jetting efficiency, whereas the flow rate of jetting after the extraction begins has significant influences on the jetting efficiency. Jetting pressure also has great effect on jetting efficiency, and converges as it increases. The closer the nozzles are located to the spudcan edge, the sooner the post-peak extraction resistance decreases. And the jetting efficiency increases with the nozzle number. The findings from the experimental studies can serve as a reference for future studies on the operation and optimization design of a jack-up jetting system.

Design and verification of relay communication system for lunar farside exploration

The Chang’e-4 probes include lander, rover and relay satellite. The relay satellite is launched before the lander and the rover, both of which will implement lunar surface exploration on the farside of moon. As one of the key components, relay communication system is responsible for establishing the communication link between ground stations and lunar surface probes. Based on the characteristics of Chang’e-4, the paper analyzes the requirement of relay communication system, and proposes the optimal scheme. The scheme takes the mission requirements into account, and inherits design of Chang’e-3 telecommunication system as far as possible, and carries out the system optimization design, which reduces the cost of lunar surface probes, then designs the working mode of relay communication system for critical stages, including powered descent, separation of the lander and the rover, sleep and reboot, and so on. At last, the paper introduces verification of relay communication system.

Performance Optimization of High-Pressure SCR System in a Marine Diesel Engine. Part I: Flow Optimization and Analysis

Selective catalytic reduction (SCR) systems for marine low-speed diesel engine can be categorized into two types—the after-turbine low-pressure SCR (LP-SCR) system and the pre-turbine high-pressure SCR (HP-SCR) system. The exhaust pressure in the HP-SCR system is higher, which requires a more compact structural arrangement. According to the exhaust conditions of marine low-speed diesel engine, the vaporizer/mixer, the bend pipe, and the sudden-changed pipe of HP-SCR system were optimized in this paper. Based on a 3D-CFD model coupled with reaction kinetics, the flow fields of a HP-SCR system with various flow-guiding devices were calculated, as well as the impact of the structural shapes and sizes of the flow-guiding devices on the exhaust flow being comprehensively analyzed. From the perspectives of the flow field, the concentration field, and the pressure loss, both the disturbance and mixing effects on the two kinds of the structural flow-guiding devices with vaporizer/mixer were evaluated. Likewise, the axial pressure distribution along the exhaust flow direction in the vaporizer/mixer was also obtained. Moreover, from the perspectives of velocity uniformity and pressure loss, diversion effects on 10 kinds of flow-guiding devices with a bent pipe and a sudden-changed pipe were evaluated—thereby even obtaining the optimization design of the HP-SCR system. By installing the flow-guiding devices in the vaporizer/mixer, the bend pipe, and the sudden-changed pipe of the HP-SCR system, the upwind velocity uniformity in front of the SCR catalyst was enhanced. In the optimization design for the HP-SCR system, the total pressure loss was 4491.3 Pa, and the standard deviation of the upwind velocity in front of the SCR catalyst was 10.17%, which can meet with the design requirement of the velocity uniformity for the marine diesel engine HP-SCR system.

Comprehensive Hydraulic Improvement and Parametric Analysis of a Francis Turbine Runner

Hydraulic turbines are usually required to operate in a wide range. The operation at off-design conditions not only reduces the unit efficiency, but also significantly deteriorates the dynamic stability of the turbines. In order to develop a turbine runner with good performances under multi operation conditions, a comprehensive hydraulic improvement has been done of a Francis turbine runner with a multipoint and multi-objective optimization design system. Compared with the initial runner, the runner generated from this method has a satisfactory improvement. In detail, unit efficiencies of the preferred runner are increased by 0.91%, 0.47% and 0.37%, respectively, under the rated head, a high head and the maximum head. The lowest pressure at blade surface is improved by 376.2 kPa under the rated head. CFD calculations are conducted to analyze the flow conditions inside of the preferred runner. In addition, runners with different main design inputs, namely blade lean, blade loading and blade meridional shape are furtherly investigated to reveal their relationship with runner’s internal flow and outer performances. In summary, this optimization system supplies satisfactory results and convincing recommendations to determine the design inputs for low-head Francis turbine runners.

Sensitivity analysis and optimum design of a hydronic snow melting system during snowfall

Snow and ice accumulation induces hazardous driving conditions due to the effect of reduced friction on the road surface. A traditional chemical-based snow melting approach is not environmentally friendly and effective when the temperature is below −3.9∘ C. Thermal snow melting techniques, such as hydronic heating system, can be an alternative to chemical-based methods. In this paper, a new approach is proposed for sizing the hydronic snow melting system. For this purpose, a transient heat transfer mechanism is considered. A complete energy balance equation including solar radiation, snowfall, and convective heat flux is used at a bridge surface. The Nelder-Mead algorithm is used to minimize the energy consumption used for snow melting by determining an optimum relation between the inlet temperature and flow rate. Since the performance of such systems depends significantly on the weather design, sensitivity analyses were performed to analyze the sensitivity of the optimum design to variations in air temperature, snowfall rate, wind speed and insulating methods. The results showed that the insulating methods and snowfall rate are the most dominant factors influencing the energy consumption of the hydronic heating system. The energy consumption rate is expected to increase by 29% without insulating the bottom and sides of a bridge deck. A 30% increase in snowfall rate leads to a rise in energy consumption by 35%. On the other hand, heat loss due to the variation in air temperature, wind speed, and solar radiation is not significant.

Vibration absorber optimization for boom-sprayer

The main task of this work is to analyze optimal design-system of the booms of boom-sprayers. The discrete-continue models of machines dynamics of such wheeled machines as boom-sprayer with elongated boom element with the attachment of dynamic vibration absorbers are offered. The algorithms for vibration decreasing of boom are received. The new vibroabsorbing elements are proposed. The paper contemplates the provision of dynamic vibration absorbers (DVA) of buffered impact masses and particle type. Such originally designed absorbers reduce vibration selectively in maximum vibration mode, without introducing vibration in other modes. The damping results from the exchange of momentum during impacts among the masses and masses and stops as the structure vibrates. A technique is developed to give the optimal DVA’s as single degree of freedom (SDOF) buffered system. The one-digit values are established not only for the dynamic vibration absorber parameters, but also for mechanical parameter of base structure – boom in connection points of the dynamic vibration absorbers. Finally, present research develops the genetic algorithms for optimal design searching by discrete-continuum DVA’s system – base system modeling.

Energetic and exergetic analysis of a solar-assisted combined power and cooling (SCPC) system with two different cooling temperature levels

Distributed energy system has received increasing attention nowadays because of its great advantages on utilizing waste heat in cascade and renewable energy flexibly. This paper proposed a solar-assisted combined power and cooling system (SCPC) which supplies power and cooling capacity at two different temperature levels for a cold storage. The cogeneration system is composed of an internal combustion engine, evacuated tube collectors, a heat storage tank and an ammonia-water combined power and cooling system. The exhaust gas of the internal combustion engine is used to generate superheated ammonia-water vapor in the ammonia-water power generation subcycle. The jacket water waste heat is recovered and assisted by the solar collector field to drive the absorption-compression subcycle. Simulation work of the proposed system was conducted, and its performance was analyzed and evaluated from the aspects of energy and exergy. Thermal efficiency of the SCPC system is 70.35% with the renewable energy ratio of 18.1%, and its exergy efficiency is 45.52%. Combined with the coefficient of exergy destruction, average energy level difference was proposed and defined to analyze the energy saving mechanism and further improvement potential of the proposed system. The effects of key parameters including turbine inlet pressure and generation pressure in low-pressure reboiler at different condensation/absorption temperatures have been investigated, providing guidance for the system's optimal design.

Design and preparation of ultra-high performance concrete with low environmental impact

Ultra-high performance concrete (UHPC) is one of the most promising materials to reduce the detrimental effects of building materials on the environment because UHPC requires fewer materials and post-maintenance in comparison with normal concrete. However, the high cost and CO2 emission of UHPC are the major factors influencing its large-scale application in China. This study presents a series of comprehensive methods, including the optimization design of the binder system, utilization of nano-particles and chemical activators as well as heat curing, to prepare UHPC with relatively lower environmental impact. The workability, compressive strength, flexural strength, hydration heat and environmental impact of UHPC were investigated. The results indicate that each of the above methods has a significant effect on the strength and carbon emission of UHPC. UHPC with cement content lower than 200 kg/m3 can be prepared by optimizing its binder system and curing conditions, and its embodied CO2 index is lower than 3 kg/MPa·m3, while the embodied CO2 index of conventional UHPC ranges from 5.5 to 7 kg/MPa·m3. The designed UHPC has a low hydration release heat which may decrease the cracking risk caused by hydration temperature rise. For improving the mechanical strength and the eco-friendliness of UHPC, chemical activating method and heat curing have a synergistic effect.

Optimization Design of Thermoelectric Power Generation System of Waste Heat Recovery

Considering that many parameters with mutual influence which were difficult to be considered comprehensively were involved in the optimization design of thermoelectric power generation system, a method that can calculate the optimal design scheme quantitatively according to the heat source characteristic was proposed in this work. The optimum working temperature of the thermoelectric module was determined by coupling the measured thermoelectric module performance curve with the temperature relationship of the cold and hot ends under the design condition. Then, based on the iterative method, the influence of various fin radiator structural parameters on heat dissipation performance was quantitatively analyzed by FLUENT software, so as to deliver the best combination of radiator parameters. The results showed that under the condition of constant heat flux density of 36 kw/m2, in order to obtain the best system efficiency, the cold end temperature should be controlled as 50 oC, and the fin radiator base thickness, fin spacing and fin height of the matched radiator should be 8 mm, 3 mm and 90 mm respectively.

Fuzzy programming model and its application of the optimization design for smart home system

ABSTRACTOwing to the extensive applications of the smart home system in the family level, the optimization design for the smart home system has received considerable research attention. In this paper, based on the practical commercial operation, the fuzzy programming model and its application are studied for the optimization design problem of the smart home system. A fuzzy multi-objective evaluation model is first proposed for the optimization design scheme. Then, the optimization design scheme and the optimization production programming are investigated based on the fuzzy set theory. Finally, the fuzzy programming model of the optimization design of the smart home system and its application are discussed.