Experimental study and energy saving analysis of a novel radiant ceiling heating system

In order to have an in-depth understanding of the metal ceiling radiant panel with capillary tubes, a radiant ceiling heating system is constructed to study the actual heating performance and thermal comfort by experiments. In addition, the energy saving potential of the novel heating system is discussed in terms of the COP （coefficient of performance） of the ground source heat pump and the exergy efficiency of the radiant terminal. The results indicate that the heating system shows high thermal stability and thermal comfort. When the system reaches a stable condition, the radiant heat transfer accounts for 62.7% of the total heat transfer, and the total heat transfer can meet the heating demands of most buildings. Compared to a radiant floor heating system, it offers advantages in a shorter preheating time, a lower supply water temperature and a stronger heating capability. The COP of the ground source heat pump is increased greatly when the supply water temperature is 28 to 33 ℃, and the exergy efficiency of the metal ceiling with capillary tubes is 1.6 times that of the radiant floor when the reference temperature is 5 ℃ The novel radiant ceiling heating system shows a tremendous energy saving potential.

Research on a TOPSIS energy efficiency evaluation system for crude oil gathering and transportation systems based on a GA-BP neural network

As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.

Analysis of Power Matching on Energy Savings of a Pneumatic Rotary Actuator Servo-Control System

When saving energy in a pneumatic system,the problem of energy losses is usually solved by reducing the air supply pressure.The power-matching method is applied to optimize the air-supply pressure of the pneumatic system,and the energy-saving effect is verified by experiments.First,the experimental platform of a pneumatic rotary actuator servo-control system is built,and the mechanism of the valve-controlled cylinder system is analyzed.Then,the output power characteristics and load characteristics of the system are derived,and their characteristic curves are drawn.The employed air compressor is considered as a constant-pressure source of a quantitative pump,and the power characteristic of the system is matched.The power source characteristic curve should envelope the output characteristic curve and load characteristic curve.The minimum gas supply pressure obtained by power matching represents the optimal gas supply pressure.The comparative experiments under two different gas supply pressure conditions show that the system under the optimal gas supply pressure can greatly reduce energy losses.

Interaction of ions in water system containing copper-zinc alloy for boiler energy saving

Copper-zinc alloy element for boiler energy saving was put in the intake of simulated boiler system to investigate the interaction and transfer of ions in water system both theoretically and experimentally.The fouling was analyzed by scanning electron microscopy(SEM)and energy dispersive X-ray detector(EDX).The results show that the transfer of calcium and magnesium ions in heat-transfer-surface-water system is affected by zinc ions dissolved from the alloy because of primary battery reaction.Some calcium ions of calcium carbonate crystal are replaced by zinc ions,the growth of aragonite crystal nucleus is retarded,and the transition of calcium carbonate from aragonite to calcite is hampered.

Self-sustained Oscillation Pulsed Air Blowing System for Energy Saving

Currently, many studies have been made for years on dimensions of pneumatic nozzle, which influence the flow characteristic of blowing system. For the purpose of outputting the same blowing force, the supply pressure could be reduced by decreasing the ratio of length to diameter of nozzle. The friction between high speed air and pipe wall would be reduced if the nozzle is designed to be converging shape comparing with straight shape. But the volume flow and pressure, discussed in these studies, do not describe energy loss of the blowing system directly. Pneumatic power is an innovative principle to estimate pneumatic system’s energy consumption directly. Based on the above principle, a pulse blowing method is put forward for saving energy. A flow experiment is carried out, in which the high speed air flows from the pulse blowing system and continuous blowing system respectively to a plate with grease on top. Supply pressure and the volume of air used for removing the grease are measured to calculate energy consumption. From the experiment result, the pulse blowing system performs to conserve energy comparing with the continuous blowing system. The frequency and duty ratio of pulse flow influence the blowing characteristic. The pulse blowing system performs to be the most efficient at the specified frequency and duty ratio. Then a pneumatic self-oscillated method based on air operated valve is put forward to generate pulse flow. A simulation is made about dynamic modeling the air operated valve and calculating the motion of the valve core and output pressure. The simulation result verifies the system to be able to generate pulse flow, and predicts the key parameters of the frequency and duty ratio measured by experiment well. Finally, on the basis of simplifying and solution of the pulse blowing system’s mathematic model, the relationship between system’s frequency duty ratio and the dimensions of components is simply described with four algebraic equations. The system could be designed with specified frequency and duty ratio according to the four equations. This study provides theoretical basis for designing energy-saving air blowing system.

Optimal energy saving in DC railway system withon-board energy storage system by using peak demand cutting strategy

A problem of peak power in DC-electrified railway systems is mainly caused by train power demand during acceleration.If this power is reduced,substation peak power will be significantly decreased.This paper presents a study on optimal energy saving in DC-electrified railway with on-board energy storage system(OBESS) by using peak demand cutting strategy under different trip time controls.The proposed strategy uses OBESS to store recovered braking energy and find an appropriated time to deliver the stored energy back to the power network in such a way that peak power of every substations is reduced.Bangkok Mass Transit System(BTS)-Silom Line in Thailand is used to test and verify the proposed strategy.The results show that substation peak power is reduced by63.49% and net energy consumption is reduced by 15.56%using coasting and deceleration trip time control.

ENERGY-SAVING MATCHING STRATEGY AND EXPERIMENTAL STUDY OF PUMPING SYSTEM FOR TRUCK-MOUNTED CONCRETE PUMP

Aiming at the high fuel consumption and use-cost of truck-mounted concrete pump , an energy-saving matching strategy of pumping system is presented and the experimental study is conducted.Since pumping system occupies most resources of engine , the matching strategy between engine and main pump is analyzed to meet the load demand and reduce the engine rational speed drop.The testing method is established to measure the fuel consumption of engine under various working conditions , and the experimental data are analyzed to find the law of the fuel consumption of engine.The system performance can be improved by adjusting the system input value.Finally , the energy-saving matching strategy is established to reduce the fuel consumption of truck for unit workload , which provides a new approach for the energy-saving of truck-mounted concrete pump.

An Energy-Saving Control Strategy on Central Air-Conditioning System

An energy-saving control strategy based on predictive control for central air-conditioning systems is proposed in this paper. The cold load model is developed to describe the dynamic characteristics of temperature control systems, and then parameters in the cold load model and in the central air-conditioning system model are estimated. Generalized predictive control (GPC) is used to establish an optimization model to minimize the consumption of energy and the control error of temperature. The simulated annealing (SA) algorithm, combined with quadratic programming, is adopted to solve the optimal problem. Contrasted with the simulation of traditional PID control, the results prove the effectiveness of this proposed strategy.

Energy Saving for Automatic Train Control in Moving Block Signaling System

With rapid development of the railway traffic, the moving block signaling system （MBS） method has become more and more important for increasing the track capacity by allowing trains to run in a shorter time-headway while maintaining the required safety margins. In this framework, the tracking target point of the following train is moving forward with its leading train. This paper focuses on the energy saving tracking control of two successive trains in MBS. Nonlinear programming method is used to optimize the energy-saving speed trajectory of the following train. The real-time location of the leading train could be integrated into the optimization process. Due to simplicity, it can be used for online implementation. The feasibility and effectiveness are verified through simulation. The results show that the new method is efficient on energy saving even when disturbances present.

Summary of Steam System Optimization and Energy Saving and Carbon Reduction Practice in Yanshan Petrochemical Company

This paper analyzes the main problems of Sinopec Beijing Yanshan Petrochemical Co.,Ltd.,such as decentralized steam system layout,many types of fuels,obvious increase in fuel cost,low operation efficiency of turbine and boiler and high self consumption loss,and puts forward and implements optimization and improvement measures such as pressure raising transformation of natural gas system,adjustment of energy consumption structure,reduction of energy consumption cost,improvement of steam production quality and equipment efficiency.The results showed that compared with the fuel consumption in 2018,the consumption of coal coke was reduced by 550000 t,the consumption of natural gas was increased by 170000 t,and the total consumption of fuel gas and fuel oil was increased by 50000 t,equivalent to 246000 t of standard coal;the purchased electricity was increased by about 5×10^(8) kW·h.Green power trading and 14.76 MW distributed photovoltaic projects were carried out.According to the calculation of 1400-1600 h annual power generation in class II photovoltaic areas and the emission factor of North China regional power grid baseline,the annual emission reduction was about 55000 t CO_(2) in 2021.After the above transformation,the goal of zero-coking is achieved;the steam consumption of units is reduced by 21.5%,the steam production of boilers is reduced by 24.9%,and the annual emission reduction is about 760000 t CO_(2),which has achieved good results.

Design of Weigh Feeder Control System for Energy Saving Using Performance-Adaptive Method

This paper discusses a design method for the control system of a weigh feeder that supplies powder and granular material at a constant rate. Most weigh feeders employed in industry are controlled by proportional and integral （PI） compensation, and the control performance is decided by the selection of parameters. To attain advanced control performance by PI control, the PI parameters are designed on the basis of generalized minimum variance control （GMVC）. In this study, to achieve user-specified control performance by GMVC-based PI control, the design parameters of GMVC are automatically adjusted using a performance-adaptive method. The control performance discussed in this study consists of the variance of the control error and that of the difference in the control input. In a conventional performance-adaptive method, the variance of the control error is reduced. In this study, to reduce energy consumption and to achieve user-specified control performance, the variance of the difference in the control input is specified and the design parameter is determined. To demonstrate its effectiveness, the proposed method is applied to an actual weigh feeder.

Research on the cooperative train control method in the metro system for energy saving

Purpose–To address the problem that the current train operation mode that train selects one of several offline pre-generated control schemes before the departure and operates following the scheme after the departure,energy-saving performance of the whole metro system cannot be guaranteed.Design/methodology/approach–A cooperative train control framework is formulated to regulate a novel train operation mode.The classic train four-phase control strategy is improved for generating specific energy-efficient control schemes for each train.An improved brute force(BF)algorithm with a two-layer searching idea is designed to solve the optimisation model of energy-efficient train control schemes.Findings–Case studies on the actual metro line in Guangzhou,China verify the effectiveness of the proposed train control methods compared with four-phase control strategy under different kinds of train operation scenarios and calculation parameters.The verification on the computation efficiency as well as accuracy of the proposed algorithm indicates that it meets the requirement of online optimisation.Originality/value–Most existing studies optimised energy-efficient train timetable or train control strategies through an offline process,which has a defect in coping with the disturbance or delays effectively and promptly during real-time train operation.This paper studies an online optimisation of cooperative train control based on the rolling optimisation idea,where energy-efficient train operation can be realised once train running time is determined,thus mitigating the impact of unpredictable operation situations on the energy-saving performance of trains.

Research on Energy Saving Technology of Load Sensitive Variable Steering System for Vehicles

In view of the large energy loss problem in the traditional full hydraulic steering system,a scheme of replacing the ordinary pump with the priority valve with the load sensitive variable pump is proposed to make the variable pump provide the corresponding flow rate according to the needs of the steering system to achieve the purpose of energy saving.Through the establishment of the system AMESim simulation model,the data comparison shows that the energy loss of the load sensitive variable steering system is significantly reduced relative to the traditional full hydraulic steering system.

Analysis of Energy Saving Achievable through Solar Photovoltaic Systems on School Roofs： A Case of the City of Rome

Embracing renewable energy technology makes a lot of sense for the public sectors and schools as it meets the government sustainability goals and provides a financially viable means of achieving carbon savings while offering income potential. This study is aimed to quantify the achievable energy saving by spread use ofphotovoltaic systems on public building stock in the city of Rome. The installation of PV （photovoltaic） systems in the historic center depends on the feasibility conditions, generally more complex compared to the cases examined in the consolidated city, because they require compliance with the formal and aesthetic characteristics of the buildings, so the choice must be made between compatible components, which allow to minimize the transformation. The suburbs are characterized by large plane roofs in bad conditions and belonging to isolated buildings, so the useful surface, according to shading condition, offers a big potential for renewable technologies. The research provides an evaluation of maximum production of solar energy and the subsequent energy saving and reduction of greenhouse gasses, using parametric data, and an evaluation of the cost-effectiveness, with a rough calculation of return on investment.

Energy saving analysis of a hybrid ground-coupled heat pump project

A hybrid ground-coupled heat pump（HGCHP）project in Nanjing,China is chosen to analyze the building energy-consumption properties in terms of different control strategies,building envelope and the terminal air-conditioning system.The HGCHP uses a supplemental heat rejecter to dissipate extra thermal energy to guarantee underground soil heat balance.The software EnergyPlus is employed to simulate the project and design the heat flow of the cooling tower and the borehole heat exchanger（BHE）.Then two feasible control strategies for the cooling tower and the borehole heat exchanger are proposed.The energy-saving potential of the building envelope is analyzed in terms of the surface color of the wall/roof.With the same terminal system,it is found that in the cooling season the heat flow of the insulated building with black wall/roof is 1.2 times more than that with white wall/roof.With the same insulated building and gray wall/roof,it is concluded that the heat pump units for a primary air fan-coil system show an annual energy consumption increase of 44.7 GJ compared with a radiant floor system.

Optimum Energy Management of the Central Air-Conditioning System in Intelligent Buildings

An optimum energy saving scheduling strategy of the central air conditioning system in an intelligent building (IB) was proposed. Based on the system analysis a set of models of the central air conditioning system was established. The periodically autoregressive models (PARM) based on genetic algorithms (GA) were used to predict the next day’s cold load. The improved genetic algorithms (IGA) with stochastic real number coding were used to finish the optimum energy saving scheduling of the system. The simulation results for the building of the Liangmahe Plaza show that the proposed strategy can save energy up to about 24 5%.

Study on shift schedule saving energy of automatic transmission of ground vehicles

To improve ground vehicle efficiency, shift schedule energy saving was proposed for the ground vehicle automatic transmission by studying the function of the torque converter and transmission in the vehicular drivetrain. The shift schedule can keep the torque converter working in the high efficiency range under all the working conditions except in the low efficiency range on the left when the transmission worked at the lowest shift, and in the low efficiency range on the right when the transmission worked at the highest shift. The shift quality key factors were analysed. The automatic trans-mission's bench-test adopting this shift schedule was made on the automatic transmission's test-bed. The experimental results showed that the shift schedule was correct and that the shift quality was controllable.

Energy Saving Cooperative Communication over Fading Channels with Relay Selection and Power Control

In order to save energy and make more efficient use of wireless channel, this article puts forward an energy saving cooperative relaying scheme which actuates the cooperative transmis- sion only when the feedback from the destination indicates failure of the direct transmission. The proposed scheme selects the optimal relay and its corresponding transmission power in each time slot based on channel condition and residual ener- gy with the objective of minimizing energy con- sumption and extending network lifetime. In the study, the f＇mite-state Markov channel model is used to characterize the correlation structure of channel fading in wireless networks, and the pro- cedure of relay selection and transmission power decision is formulated as a M arkov decision process. Numerical and simulation results show that the proposed scheme consumes less energy and prolongs the network lifetime.

Coupled simulation of BES-CFD and performance assessment of energy recovery ventilation system for office model

Thermal comfort and indoor air quality as well as the energy efficiency have been recognized as essential parts of sustainable building assessment. This work aims to analyze the energy conservation of the heat recovery ventilator and to investigate the effect of the air supply arrangement. Three types of mixing ventilation are chosen for the analysis of coupling ANSYS/FLUENT （a computational fluid dynamics （CFD） program） with TRNSYS （a building energy simulation （BES） software）. The adoption of mutual complementary boundary conditions for CFD and BES provides more accurate and complete information of indoor air distribution and thermal performance in buildings. A typical office-space situated in a middle storey is chosen for the analysis. The office-space is equipped with air-conditioners on the ceiling. A heat recovery ventilation system directly supplies flesh air to the office space. Its thermal performance and indoor air distribution predicted by the coupled method are compared under three types of ventilation system. When the supply and return openings for ventilation are arranged on the ceiling, there is no critical difference between the predictions of the coupled method and BES on the energy consumption of HVAC because PID control is adopted for the supply air temperature of the occupied zone. On the other hand, approximately 21% discrepancy for the heat recovery estimation in the maximum between the simulated results of coupled method and BES-only can be obviously found in the floor air supply ventilation case. The discrepancy emphasizes the necessity of coupling CFD with BES when vertical air temperature gradient exists. Our future target is to estimate the optimum design of heat recovery ventilation system to control CO2 concentration by adjusting flow rate of flesh air.

CROSS LAYER COORDINATED ENERGY SAVING STRATEGY IN MANET

Mobile Ad hoc NETwork (MANET) consists of a set of mobile hosts which can operate independently without infrastructure base stations. Energy saving is a critical issue for MANET since most mobile hosts will operate on battery powers. A cross layer coordinated framework for energy saving is proposed in this letter. On-demand power management, physical layer and medium access control layer dialogue based multi-packet reception, mobile agent based topology discovery and topology control based transmit power-aware and battery power-aware dynamic source routing are some of new ideas in this framework.