Heat absorption control equation and its application of cool-wall cooling system in mines

In order to solve the heat damages in deep mines, a cool-wall cooling technology and its working model are proposed based on the principles of heat absorption and insulation in this paper. During this process, the differential equation of thermal equilibrium for roadway control unit is built, and the heat adsorption control equation of cool-wall cooling system is derived by an integral method, so as to obtain the quantitative relationship among the heat absorption capacity of cooling system, the heat dissipating capacity of surrounding rock and air temperature change. Then, the heat absorption capacity required by air temperature less than the standard value for safety is figured out by section iterative method with the simultaneous solution of heat absorption control equation and the heat dissipation density equation of surrounding rock. Finally, the results show that as the air temperature at the inlet of roadway is 25 ℃, the roadway wall is covered by heat-absorbing plate up to 39% of the area, as well as the cold water is injected into the heat-absorbing plate with a temperature of 20 ℃ and a mass flow of 113.6 kg/s, the air flow temperature rise per kilometer in the roadway can be less than 3 ℃.

Simulation of Greenhouse Heating System Using Fuzzy Smith Cascade Compound Control

Aiming at characteristic of time delay, time-varying parameters and much disturb in glass greenhouse heating system, fuzzy smith cascade compound control policy based on typical PID cascade compound control policy is proposed. Simulation results show that it is effective to overcome the influence of time delay on stability of control system and the system possesses strong robust and good dynamic performance..

Simulation Study on Heat Value Control System of Natural Gas Used for Color TV Tubes Production

In order to know the character of the heat value control system, determine the influence of natural gas quality and flow on the heat value, and learn how to adjust the parameters of control system, the model of the whole system is established, and simulation of the system is adopted in Matlab/Simulink. The simulation result shows that the feedback system with feed-forward block controls the heat value very well, and the simulation result can effectively guide the engineering design of the heat value control system, and the efficiency of engineering is improved.

Operating Parameters of the District Heating Substation Cooperating With the Installation of Technological Air Conditioning With High Efficiency of Heat Recovery

The article analyses the problem of determining the operating parameters of the district heating substation cooperating with the air heating system in technological air conditioning systems equipped with heat exchangers with high efficiency of heat recovery.Attention was paid to the correct selection of heat exchangers for the heat output balance depending on the heat recovery protection algorithms against a drop in the temperature of the heat transfer surface below 0℃.Critical parameters were determined in Polish climatic conditions,at which the operation of the heat recovery exchanger in the air conditioning system is switched off or limited.It has been proven that the proper functioning of the district heating substation cooperating with the installation of air conditioning with high heat recovery efficiency requires the use of two heat exchangers with different characteristics,equipped with properly selected temperature control systems.The optimal model of cooperation between the technological air conditioning system and the heating substation was also indicated.

Economic Model Predictive Control for Hot Water Based Heating Systems in Smart Buildings

This paper presents a study to optimize the heating energy costs in a residential building with varying electricity price signals based on an Economic Model Predictive Controller (EMPC). The investigated heating system consists of an air source heat pump (ASHP) incorporated with a hot water tank as active Thermal Energy Storage (TES), where two optimization problems are integrated together to optimize both the ASHP electricity consumption and the building heating consumption utilizing a heat dynamic model of the building. The results show that the proposed EMPC can save the energy cost by load shifting compared with some reference cases.

Application of HEMS cooling technology in deep mine heat hazard control

This paper mainly deals with the present situation, characteristics, and countermeasures of cooling in deep mines.Given existing problems in coal mines, a HEMS cooling technology is proposed and has been successfully applied in some mines.Because of long-term exploitation, shallow buried coal seams have become exhausted and most coal mines have had to exploit deep buried coal seams.With the increase in mining depth, the temperature of the surrounding rock also increases, resulting in ever increasing risks of heat hazard during mining operations.At present, coal mines in China can be divided into three groups, i.e., normal temperature mines, middle-to-high temperature mines and high temperature mines, based on our investigation into high temperature coal mines in four provinces and on in-situ studies of several typical mines.The principle of HEMS is to extract cold energy from mine water inrush.Based on the characteristics of strata temperature field and on differences in the amounts of mine water inrush in the Xuzhou mining area, we proposed three models for controlling heat hazard in deep mines:1) the Jiahe model with a moderate source of cold energy;2) the Sanhejian model with a shortage of source of cold energy and a geothermal anomaly and 3) the Zhangshuanglou model with plenty of source of cold energy.The cooling process of HEMS applied in deep coal mine are as follows:1) extract cold energy from mine water inrush to cool working faces;2) use the heat extracted by HEMS to supply heat to buildings and bath water to replace the use of a boiler, a useful energy saving and environmental protection measure.HEMS has been applied in the Jiahe and Sanhejian coal mines in Xuzhou, which enabled the temperature and humidity at the working faces to be well controlled.

Design and control of methyl acetate-methanol separation via heat-integrated pressure-swing distillation

Design and control of pressure-swing distillation(PSD) with different heat integration modes for the separation of methyl acetate/methanol azeotrope are explored using Aspen Plus and Aspen Dynamics. First, an optimum steady-state separation configuration conditions are obtained via taking the total annual cost(TAC) or total reboiler heat duty as the objective functions. The results show that about 27.68% and 25.40% saving in TAC can be achieved by the PSD with full and partial heat integration compared to PSD without heat integration. Second,temperature control tray locations are obtained according to the sensitivity criterion and singular value decomposition(SVD) analysis and the single-end control structure is effective based on the feed composition sensitivity analysis. Finally, the comparison of dynamic controllability is made among various control structures for PSD with partial and full heat integration. It is shown that both control structures of composition/temperature cascade and pressure-compensated temperature have a good dynamic response performance for PSD with heat integration facing feed flowrate and composition disturbances. However, PSD with full heat integration performs the poor controllability despite of a little bit of economy.

Dynamic Simulation of the Aircraft Environmental Control System

The dynamic research of aircraft environmental control system (ECS) is an important step in the advanced ECS design process. Based on the thermodynamics theory, mathematical models for the dynamic performance simulating of aircraft ECS were set up and an ECS simulation toolbox (ECS_1.0) was created with MATLAB language. It consists of main component modules (ducts, valves, heat exchangers, compressor, turbine, etc.). An aircraft environmental control system computer model was developed to assist engineers with the design and development of ECS dynamic optimization. An example simulating an existing ECS was given which shows the satisfactory effects.

Identification and PID Control for a Class of Delay Fractional-order Systems

In this paper, a new model identification method is developed for a class of delay fractional-order system based on the process step response. Four characteristic functions are defined to characterize the features of the normalized fractional-order model. Based on the time scaling technology, two identification schemes are proposed for parameters U+02BC estimation. The scheme one utilizes three exact points on the step response of the process to calculate model parameters directly. The other scheme employs optimal searching method to adjust the fractional order for the best model identification. The proposed two identification schemes are both applicable to any stable complex process, such as higher-order, under-damped U+002F over-damped, and minimum-phase U+002F nonminimum-phase processes. Furthermore, an optimal PID tuning method is proposed for the delay fractional-order systems. The requirements on the stability margins and the negative feedback are cast as real part constraints U+0028 RPC U+0029 and imaginary part constraints U+0028 IPC U+0029. The constraints are implemented by trigonometric inequalities on the phase variable, and the optimal PID controller is obtained by the minimization of the integral of time absolute error U+0028 ITAE U+0029 index. Identification and control of a Titanium billet heating process is given for the illustration. © 2014 Chinese Association of Automation.

Charging System of ECRH High-Voltage Power Supply and its Control System

High-voltage power supply (HVPS) of Electron Cyclotron Resonance Heating (ECRH) for HT-7 and HT-7U is presently being constructed. The high voltage (100 kV) energy of HVPS is stored in the capacitor banks, and they can power one or two gyrotrons. All the operation of the charging system will be done by the control system, where the field signals are interfaced to programmable logic controller (PLC). The use of PLC not only simplifies the control system, but also enhances the reliability. The software written by using configuration software installed in the master computer allows for remote and multiple operator control, and the status and data information is also remotely available.

瓦斯蓄热氧化井筒加热系统智能化研究

针对瓦斯蓄热氧化井筒加热系统存在的智能化水平落后于实际生产需求,影响生产效率和生产安全的问题,在原瓦斯蓄热氧化井筒加热控制系统初步具备远程控制的基础上,开展了智能化相关研究。介绍了瓦斯蓄热氧化井筒加热系统的工艺单元结构,重点分析了系统监控远程化、调控智能化、故障诊断智能化等方面的研究。某煤矿瓦斯蓄热氧化井筒加热系统智能化改造的应用案例表明:改造后的系统实现了远程监测及控制、故障智能化诊断及智能化调控功能,提高了装置运行安全性和经济性。

加热炉炉温智能控制系统设计与实现

加热炉作为钢铁工业生产的重要设备,对钢坯等物料加热质量有重要的影响,能够将金属物料加热到轧制所需的温度。目前,加热炉已经应用到冶金、机械、建材、轻工等多个领域。加热炉属于高耗能窖炉,资源耗费较大,在加热过程中会随着烟气损耗大量的热量,随着科技的快速发展,智能控制技术已经运用工业生产中,通过智能控制系统对加热炉炉温进行控制,可以有效对温度进行调节,符合锻造需求。综合分析加热炉的构成以及工作原理,并介绍加热炉的炉温控制重点,并提出一种加热炉的炉温智能控制系统设计方案,希望能够提升加热炉的生产效率,改善产品质量,节约资源减少环境污染问题。

辊底式加热炉钢坯位置控制系统设计

目前,辊底式加热炉钢坯位置控制系统的设计和优化成为当前研究的焦点之一。随着科技的不断进步,控制系统技术在工业生产中得到了广泛应用。通过精确控制钢坯的位置可以实现更加均匀和高效的加热过程,从而改善产品质量,减少能源消耗,降低环境影响。因此,介绍了辊底式加热炉钢坯位置控制系统的设计,旨在提高钢坯的加热效率和质量控制。系统能够实现高精度的钢坯位置控制,以确保每块钢坯在加热炉中的位置和温度均匀分布。此外,系统具有智能控制策略以及数据采集等功能,以实时监测钢坯的位置和温度,为生产过程的优化提供重要信息,有望在未来的钢铁生产中发挥关键作用,实现生产效率的提高和工业可持续性的实现。

基于Smith模糊PID控制的固体电蓄热供热温控系统研究

固体电蓄热供热的温控系统存在滞后性,导致系统响应缓慢,抗干扰能力和能源利用率大大降低。为了解决这一问题,以某高校的固体储能供热示范工程为基础,提出了采用基于Smith模糊PID控制的方法对温控系统进行控制。实验结果显示,该温控系统的控温精度可达到±0.8℃,调节时间缩短了5 min。分析结果表明,与传统的PID控制方法相比,这种控制方法能够更有效地减小控制过程中的扰动影响,显著缩短调节时间,使系统更快进入稳定状态,有效克服了传统大滞后系统对稳定性的不利影响,温控效果优于传统PID控制。

深井矿山热害防治及制冷降温技术应用

随着金属矿山开采深度的增加,高地温越加显现,而矿山在热害控制方面经验不足、个体防护及培训缺失、有效的机械制冷技术应用较少等,亟待加强深井金属矿山热害防治安全技术相关研究。本文分析了深井矿山热环境对作业人员、生产效率的影响,总结了热害防治的综合措施,包括通风系统优化、热源控制、个体防护、压缩空气制冷、机械制冷等方面,列举了南非、澳大利亚两座典型深井矿山机械制冷降温技术的典型应用,供其他深井矿山借鉴。

船舶柴油机余热回收试验台测控系统设计及试验研究

为提高船舶柴油机余热回收试验台的自动化程度,开发了基于STM32和LabVIEW的船舶柴油机余热回收试验台测控系统。系统能够同步测量换热器进出口冷却水的温度和流量,通过改进PI算法自动控制换热器出口的冷却水温度,并在上位机界面上动态显示测量数据和控制效果,具备数据采集、远程控制、数据保存和故障报警等模块化功能。测试结果表明,数据采样周期小于500ms,冷却水流量的调节精度达0.1m^(3)/h,在换热器出口冷却水温度设定值为18.8℃时超调量为0.5%。

换热站并联水泵分布式优化控制

针对现有换热站并联水泵优化算法在集中式架构下控制适应性不足的问题,本文提出了一种改进的分布式并联水泵优化算法.首先,建立了并联水泵的分布式控制系统,并对该优化问题的数学模型进行描述,在目标函数中引入自适应非线性因子;然后,设计了改进的分布式果蝇优化算法,在该算法中每台水泵的控制器仅通过与邻居控制器交互信息即可完成并联水泵的优化;并且,在嗅觉搜索阶段,使用正弦余弦策略替代赋予个体距离与方向的随机策略;最后,以两个实际换热站中不同并联水泵系统为例对算法进行仿真验证,并基于仿真结果进行性能分析.结果表明,相较于传统算法,改进的分布式果蝇优化算法能得到更优的控制策略,有着收敛速度快、稳定性好和鲁棒性强的特点;并且该算法适用于不同系统的并联水泵优化问题,具有可扩展性.在实际工程验证中相较于集中式算法,该算法在总功率和计算时间上分别平均降低了5.47%和29.90%,因此,能够满足实际换热站中对并联水泵热负荷优化分配的需求.

基于MPC的光电热联合系统建模与控制优化

为解决我国北方地区冬季采暖产生的能源消耗与环境污染问题,改善光资源丰富、较丰富地区光能利用率不足的现状,充分利用谷电和日照优势,针对太阳能利用与建筑采暖相结合的分布式能源系统性问题,提出一种基于TRNSYS动态建模与数值建模相结合的光电热联合供暖系统。综合考虑小范围内供暖温度的时滞性以及系统各设备的出力情况,联合Matlab搭建模型预测控制器(MPC),提出一种基于MPC的误差实时校正优化控制策略。分析表明:采用MPC的控制优化,在热负荷跟踪方面,最大误差降低4.16%,平均误差降低2.79%;在室内温度控制方面,最大偏差降低1.2℃,平均偏差降低0.2℃;在太阳能利用占比方面,太阳辐射强度趋近于800 W/m^(2)时,太阳能利用占比差距达最大8.9%。分析结果说明该系统可以更快速、更准确地跟踪建筑热负荷波动,并且有效抑制室内温度波动,提高清洁能源的利用率。

基于单片机的热处理炉温度控制系统设计与实现

热处理炉是供炉料热处理加热用的燃料炉或电炉,热处理炉温度范围比较大,而且对炉温的控制要求非常严格,只有控制好炉温,才能防止金属的氧化或脱碳。随着工业技术的不断进步和产业升级,高质量、高性能材料的需求日益增加,这对于热处理技术的要求也日益提高。然而,传统的人工控制方式往往存在温度波动大、稳定性差等问题,难以满足现代材料工程的要求。基于单片机的热处理炉温度控制系统设计与实现的研究在实现高质量产品的生产过程中具有重要意义。综合论述了热处理技术与温度控制、热处理炉温度控制系统设计以实现对热处理炉温度的精确控制。通过不断的优化和创新实现了热处理炉温度的智能化控制,为工业生产和产品质量提升做出更大的贡献。