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.

Control performance and energy saving of multi-level pressure switching control system based on independent metering control

Aiming at the problem of large energy consumption in hydraulic control system with large load and variable working conditions,based on the multi-level pressure switching control system(MPSCS),a multi-level pressure switching control system based on independent metering control is proposed combined with the independent metering control technology.The configuration principle of the system is given,the mathematical model of this system is established,and the control strategy of the system under 4 different working quadrants is put forward.Finally,the control performance and energy saving characteristics of the system are tested.The test results show that the switching of high and low pressure power supply has a certain effect on the response of step position and ramp position under impedance working condition.The displacement curves show slow climbing or abrupt change of ramp position,and the position accuracy is less than 1 mm.The multi-level pressure switching control system based on independent metering control can recover and store energy under the transcendence working conditions.The control accuracy is about 1 mm,and the energy recovery rate is about 70%~80%.

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.

A Stable Energy Saving Adaptive Control Scheme for Building Heating and Cooling Systems

This paper presents a stable, nonlinear, adaptive control scheme for building heating and cooling systems. The proposed controller utilizes the principle of adaptive one step ahead control and aims at reducing the energy consumed for heating or cooling a building. The design steps are discussed in details and a proof of global stability is also provided. Also, the performance of the proposed controller is demonstrated on a simulated building thermal model.

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.

Application Analysis of Ad Lamp-box Controller

The ad lamp-box controller is designed in consideration that ordinary urban ad lights usually remain lit through the night and a specially assigned staff needs to be on duty to control their switches.It can be automatically controlled with a photo resistance testing the day and night as well as a CD4060 chip controlling the length of time interval between switching the ad lamp-boxes on and off.In this way,both energy and labor can be saved with the controller.It is matching with the target of"constructing a conservation-minded society"in our country and deserves to be promoted in market with its practical significance.

环境补贴能提升企业碳绩效吗--基于A股上市公司实证分析

环境补贴既是国家实现“双碳”目标的宏观调控手段,也是减轻企业环保负担、引导企业节能减排的推动力。选取2014~2019年接受环境补贴的1094家A股上市公司3735个观测值作为研究样本,采用双向固定效应模型,实证探究环境补贴对企业碳绩效的影响。研究表明,环境补贴与企业碳绩效显著正相关且具有滞后性特征,异质性检验发现,成立时间长的企业、国有企业、东部地区与中低污染企业环境补贴作用效果显著;进一步研究发现,环境补贴中的节能减排补贴与企业碳绩效显著正相关,环境治理补贴对企业碳绩效起负向作用。据此,提出环境补贴应以降碳为重点、减污降碳协同增效为目的等建议。

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.

“双碳”背景下医院住院病人水控管理系统的定量分析——以某三甲医院2019-2022年数据为例

针对医院在“双碳”目标下管理和控制住院病人洗澡用水的问题进行了深入研究,通过整理某三甲医院2019-2022年的水控数据,定量分析了住院病人的用水情况,并评估了各种因素对用水量的影响。研究结果表明,即使在严格落实“一床一陪护”制度的今天,水控系统仍然能够显著降低住院用水,同时日间手术量、床位周转率等指标也与住院患者用水量有相关性。提出与运用的定量分析模型对医院精细化管理有积极意义,提供了对病区管理评价的新工具。

Pressure control strategy for pump motor energy transfer unit

Multi-level pressure source system is a novel hydraulic system with distinct advantage of energy saving. In order to balance each pressure level of the multi-level pressure source system, a pump motor energy transfer unit is usually equipped. However, the pump motor energy transfer has the characteristics of poor starting and low response, which cause long time of pressure adjustment and large pressure jitter when the transformer is switched to system suddenly and the motor-side pressure has pressure impact when rail of the pump-side is switched. To address these problems, this paper proposes a compound control strategy of feedforward compensation control with Fuzzy-PID to improve the controllability of the multi-level pressure source system. A test rig of the pump motor energy transfer unit is built and the controllability of compound controller and PID controller are compared. The experiment results show that, compared with the traditional PID, the adjustment time and the pressure impact are reduced by 20% and 25% with the proposed compound control strategy. Therefore, the presented compound control strategy can be used to improve starting performance and robustness of the pump motor energy transfer unit control system.

Design of Fuzzy Controller for Central Air Conditioner

A structure of central air conditioning system in building and its running pattern are proposed in order to perform optimum energy saving strategy. The design of room temperature controller is taken as an example to discuss the design of fuzzy controller using common microprogrammed control unit (MCU) in detail. Based on fuzzy theory the query control tables fixed in read only memory (ROM) of MCU are established to realize the energy saving in the room temperature controller and the reasoning procedure is analyzed. The diagram of hardware design and the flow chart of software of room temperature controller are presented. The results show that the proposed method is practical and effective to achieve the energy saving goal.

Control performance monitoring and advanced control towards energy conservation

High performance control of an interactive process such as iron and steel plant relies on ability to honor safety and operational constraints;reduce the standard deviations of variables that need to be controlled(e.g.product quantity,quality );de-bottlenecking the process;and,maximize profitability or lower cost(e.g.energy savings, improve hot metal content).These objectives may be prioritized in this order,but can vary and are very difficult to achieve optimally through conventional control.A multivariable predictive controller solution,along with its extensive inferential sensor and built-in optimizer,provides online closed loop control and optimization for many interactive metal and mining processes to lower the energy cost,increase throughput,and optimize product quality and yield. Control loop performance is also a key factor to improve iron and steel plant automation and operation result; Honeywell CPM offers vender-independent product which provides monitoring,tuning,modeling of control loop and sustainable loop performance analysis and maintenance solution towards operation stability and energy saving.

Energy Saving and Pollutant Reduction: Nuclear vs Thermal

This paper presents the development status of thermal and nuclear power industries in China in recent years. It makes a comparison between the two industries from the aspects of reliability, economics, energy saving and pollutant reduction, by which the effects of expanding nuclear power on pollution control, resources conservation and eff icient energy use are evaluated, and several points of view are summarized.

Game analysis of building energy saving behaviors between government and developers

Information asymmetry phenomenon and the differences between the main body's earning targets,which are existing in the building energy saving field,have made the game behaviors of its economic activities become inevitable.There are strategies choice between government departments and the developers,when the building energy saving work is carried out under the government control.Based on the players based assumptions,the path of player's behavior strategy choices is analyzed,expected revenue models are established and mixed Nash equilibrium is obtained in this paper.Based on the analysis results,the incentive strategy enlightenment could be concluded that it is particularly important to design the scientific incentive system for developers to develop energy-saving buildings reasonably and for the government to implement effective control;the role of informal system in encouraging developers to develop energy-saving buildings should not be ignored.

Design and Development of a New Control System for Improving Energy Efficiency and Demand Response

One of the best strategies for improving energy efficiency in any system is using the energy resources in the facilities properly.Using energy systems only when they are absolutely necessary is one of the best cost-benefit ratio strategies,i.e.the best energy saving strategy is,not using it.The aim of this paper resides on introducing a new Energy Management and Control System(EMCS),developed by the authors,which has been installed at the Universitat Politècnica de València.Alongside the paper,the architecture,the components and the installation cost analysis of the EMCS,as well as management actions implemented in the university and the obtained results are presented.Furthermore,this innovative system has been designed to improve demand response in energy systems by providing consumers with a tool for responding actively to energy demands,and also to provide all the different electrical market agents with a communication and business platform for exchanging information.

“空气源热泵-太阳能”热水系统在高校学生公寓的应用

学生公寓热水需求量大且用水时间较为分散,选择少污染且高效的热源形式,对高校的节能减排有重要的意义。空气源热泵辅助太阳能热水系统水温恒定,可全天候供应热水,满足阴雨天及冬季使用热水需求,智能化程度高,节能效果明显且项目回收周期短,可以在高校中推广使用。介绍山东某高校公寓实际运行的空气源热泵辅助太阳能热水系统及其控制原理;并通过对电热水器和单独采用空气源热泵制取热水方式的年耗电量计算,与实际运行项目的年耗电量比较,对其节能性进行分析。由于对系统各设备的启停采用了智能控制系统,能够对系统运行模式进行灵活调控,使得该系统比电热水器节电75%,比独立空气源热泵系统节电30%。根据2021年项目实际年收入,预计该系统回收周期为4.2年。

高校宿舍太阳能-空气源热泵复合热水系统设计与应用探讨

在当前积极倡导节能减排的政策要求下,可再生能源利用逐渐普及。以西安建筑科技大学学生宿舍太阳能-空气源热泵复合热水系统为例,阐述了复合热水系统的构成、工作原理,对太阳能集热系统、空气源热泵换热系统、热水供水系统等进行了设计计算,给出了集热器、热泵机组、集热水箱、供热水箱等主要设备的选型结果,提出了系统运行控制方案,并结合实际运行工况下的热性能数据,计算得到系统在不同季节的太阳能保证率、热泵能效比COP值,表明系统具有极大的节能性。

Energy Saving Analysis and Simulation for Home Electricity

This paper presents the energy saving method by applying the voltage control technique on a single-phase AC source to a thyristor rectifier and an IGBT inverter with LC filter. Based on the LC filter parameter, the values of the gain for the controller are obtainable. The proposed controller structure consists of two loops arranged in a cascaded model. The output of the first loop is the capacitor current. This current is added to the load current in order to obtain the current reference. This reference current value will be compared with the inverter current which produces the error signal to be fed into the second loop in the cascade system. The output of the second loop is the inverter voltage. This voltage is added to the load voltage to produce the voltage reference. This reference is fed to the pulse width modulation generator via the controller and compared with the triangular wave. This energy-saving circuit is designed in blocks using MATLAB Simulink.

BAS-BP控制模型在化工厂空调节能中的应用研究

实施能源控制,降低化工材料企业能源消耗对企业实施转型升级,提升企业市场竞争力具有至关重要的意义。对化工企业厂房空调系统进行了分析,将空调系统能效比作为节能智能控制的目标。采用BAS对BP神经网络初始权值与偏置进行优化,得到了BAS-BP模型,通过该模型对厂房空调系统实施节能智能控制。将该节能智能控制模型应用于某化工材料企业中,通过520次迭代,厂房内温度区域稳定,为24.5℃,同时得到了各影响因素的值。这对化工材料企业厂房空调节能智能控制提供了数据支撑。

数控机床节能策略TL-DBN模型设计及优化

机床运行控制性能受到实际车间环境与生产工艺条件的综合影响,如何提高节能效果是保证机械制造成本的一个关键。为了提高数控机床多台设备协调工作的能力,进而实现节能的效果,设计了一种利用迁移学习方法来实现CNC机床的节能控制过程。建立了以RF实现驱动功能的离散CNC机床能耗调控模型,由此减小等待阶段所消耗的能量。研究结果表明:相比较其他算法,TL-DBN模型决策误差达到3.2%的最低值,迁移学习过程能够优化节能决策的效果,能够使机床达到理想的节能效果。该研究的控制方案为实现生产过程管控提供指导,为后续的控制优化奠定一定的理论基础。