感应加热过程的计算机仿真

系统地介绍了用于感应加热过程的计算机仿真的各种方法，包括三维变步长有限元法，电磁场和温度场耦合计算，场路结合分析，耦合电路法等，并对各种方法进行了比较。     

螺旋推进器影响多功率微波加热系统加热均匀性的仿真分析

为改善工业微波加热过程中加热不均匀问题,通过仿真带有螺旋推进器管道式加热装置,研究螺旋转速、流体入口流速以及螺旋材料对加热均匀性的影响。通过结合麦克斯韦方程、传热方程以及连续性方程并结合动网格进行多物理场耦合仿真,结果表明增大螺旋转速温度变异系数先减小后增大,在层流状态下转速越大加热均匀性越好,在湍流状态下转速越大加热均匀性越差。入口流速与螺旋转速共同影响加热均匀性,会使温度变异系数在一定范围内波动。随着入口流速的增大螺旋转速对流体平均温度的影响逐渐减小。采用微波反射型材料的加热效果要优于微波穿透型材料。探究了不同因素对微波加热均匀性的影响,对液体材料微波加热的工业应用具有指导意义。     

油田射孔器材试验装置加热系统的数学模型与仿真分析

根据射孔器材耐高温高压试验装置的技术要求,设计了井式双循环电加热炉系统,建立了该加热炉炉膛传热过程的数学模型。通过仿真,分析了该加热系统工艺参数对沿程温度场分布的影响,为高精度控制该装置高温高压釜内的油温度起到了指导和预测作用。在实际测量中验证了该模型计算的有效性。     

原位热脱附修复污染土壤加热效果模拟和试验研究

原位热脱附技术具有工艺原理简单、效率高、安全稳定等显著优点,能有效应对污染企业被迫搬迁、改造和关停后所产生的污染场地遗留问题.通过FLUENT软件模拟单根加热棒在土壤中的加热过程,结果表明,加热棒能对周围污染土壤进行有效升温,随着加热时间的增加,土壤温度逐渐升高;同时,测温点距离加热棒表面越近,则温度越高.因此,热脱附...     

一种改进的工业微波炉加热控制PID技术

讨论了一种基于共轭梯度算法的改进的BP神经网络的PID控制技术,利用神经网络的自学习能力,实现对工业微波加热炉中温度的智能控制,用于解决微波加热系统的时变性,不确定性和非线性方面的问题。仿真结果表明这种建立在神经网络模型上的PID控制技术能够满足工业微波加热中的温度控制要求。     

车轮淬火加热过程温度场的数值模拟

根据马钢车轮淬火加热炉的实际状况,建立了车轮淬火加热过程温度场计算模型。应用该模型对某规格车轮的淬火加热过程温度场进行了模拟,并应用在线测温系统对该规格车轮淬火加热过程的温度变化进行了实测,结果与实测结果吻合较好。通过模拟发现,该规格车轮现行加热时间过长,有很大的压缩空间。     

真空钎焊炉加热体的数值模拟

通过建立基于ANSYS平台的真空钎焊炉加热体的三维有限元模型,采用热电耦合单元,模拟出了该加热体将电流转换为焦耳热并通过辐射传热将热量传递给周围环境的过程中加热体自身温度场、电压、电流密度等的分布情况。同时通过提取ANSYS后处理数据得到了该过程中的总体焦耳热生成及辐射热损失。     

基于感应加热技术的轴承拆装器的计算机仿真研究

在研究感应加热基本理论的基础上,通过MATLAB及ANSYS有限元分析软件,对所设计的轴承内环感应拆装器进行了计算机仿真研究.通过对感应加热过程中拆装器内电磁场的计算机模拟,得出了磁场的分布规律,证明了涡流集肤效应的存在,为感应加热装置的设计奠定了基础.     

柴油机燃烧室改进的模拟仿真研究

首先介绍了柴油机燃烧室设计的尺寸特点,然后再在原燃烧室的基础上对它的尺寸做了一些改进,并通过大型CFD分析软件AVL-FIRE对修改后的燃烧室模型进行了流场数值模拟,计算出缸内流场的流动分布,对比分析得出燃烧室尺寸对气体流动的影响。     

谐振式曲轴弯曲疲劳试验及其动力学仿真模拟分析研究

本文介绍了谐振式曲轴弯曲疲劳试验及其动力学仿真模拟分析研究,根据谐振式曲轴弯曲疲劳试验机的试验原理,对这一试验装置进行仿真模拟,实现试验与计算的相互印证,并探索、寻求采用仿真计算简化试验流程的可能性。     

家用太阳热水器与太阳热水系统的技术经济比较

分析了户用太阳热水器和太阳热水系统工程的经济技术特点,对两者成本构成、项目财务净现值、投入回收期和财务内部收益率等有关指标进行了经济技术比较.分析比较表明,太阳热水系统与家用热水器相比,节省安装占地,与建筑相结合得好,在降低成本,缩短投资回收期,提高经济效益方面有明显的优势.     

Dynamic modelling and simulation of a room with hot water baseboard heater

A dynamic model of a room with a hot water baseboard heater is developed. In the modelling methodology used, a typical finned‐tube baseboard heater with its cover was divided into several control volumes. The mass, energy balance and momentum equations were formulated and solved for each control volume. The dynamic model was used to study the effect of important design and operating parameters on the heat output rate of the baseboard heater. Simulation runs showing the dynamic responses of airflow rates, air temperature from the heater, and hot water temperature are presented. Copyright © 2005 John Wiley & Sons, Ltd.     

Simulation and experimental investigation of two hybrid solar domestic water heaters with drain water heat recovery

In this paper, the performance of two solar domestic hot waters (SDHW) with drain water heat recovery (DWHR) units is investigated. Both SDHW systems are recently installed at the Archetype Sustainable Twin Houses at Kortright Center, Vaughan, Ontario. The first SDWH system in House A consists of a flat plate solar thermal collector in combination with a gas boiler and a DWHR unit. The second SDHW system in House B includes an evacuated tube solar collector, an electric tank, and a DWHR unit. Both systems are modeled in TRNSYS, and the models are validated by experimental data. The addition of the DWHR and the flat‐plate solar thermal collector would result in 1831 kWh of annual energy saving in House A. While the addition of the DWHR and the evacuated tube collector in House B would result in an annual energy saving of 1771 kWh. Subsequently, the models are used to investigate the performance of similar systems for five major Canadian cities of Halifax, Montreal, Toronto, Edmonton, and Vancouver. The conjunctions of solar thermal collectors with DWHR units are found most beneficial in Edmonton. It is also noted from experimental and simulated results that flat‐plate solar collector‐based water heater produced more thermal energy than the system based on the evacuated tube solar collector for all major Canadian cities. Copyright © 2015 John Wiley & Sons, Ltd.     

MPC-based interval number optimization for electric water heater scheduling in uncertain environments

In this paper, interval number optimization and model predictive control are proposed to handle the uncertain-but-bounded parameters in electric water heater load scheduling. First of all, interval numbers are used to describe uncertain parameters including hot water demand, ambient temperature, and real-time price of electricity. Moreover, the traditional thermal dynamic model of electric water heater is transformed into an interval number model, based on which, the day-ahead load scheduling problem with uncertain parameters is formulated, and solved by interval number optimization. Different tolerance degrees for constraint violation and temperature preferences are also discussed for giving consumers more choices. Furthermore, the model predictive control which incorporates both forecasts and newly updated information is utilized to make and execute electric water heater load schedules on a rolling basis throughout the day. Simulation results demonstrate that interval number optimization either in day-ahead optimization or model predictive control format is robust to the uncertain hot water demand, ambient temperature, and real-time price of electricity, enabling customers to flexibly adjust electric water heater control strategy.     

蒸汽供暖和热水供暖方案比较和应用

办公室和厂房供暖常采用蒸汽供暖或热水供暖。结合实际情况分析比较了两种供暖方式的优缺点。蒸汽供暖一次性投入较小,但使用维护费用较大;热水供暖和蒸汽供暖相比需增设一套热水循环装置、回水池和回水管路,但运行费用相对较少,且可最大程度地减少跑、冒、滴、漏现象的发生,从而可大大提高设备和材料的利用率,降低成本,最终起到节能降耗的作用,应广泛推广和应用。     

An experimental investigation into the performance of a domestic forced circulation solar water heater under varying operating conditions

An experimental investigation is carried out on a forced circulation solar water heater to assess its performance under various operating conditions. The system consisted of two identical collectors of total absorber area of 3.45 m² and a storage tank of 200 litre capacity. Experiments were carried out during clear days with and without system loading for two water mass flow rates through the collector; namely 0.1305 kg/s and 0.06525 kg/s. The system was operated without thermostat control and with thermostat control at maximum and minimum settings. The collector efficiency improved with system loading. The improvement was better with increased hot water withdrawal from the system.     

An experimental investigation into the performance of a domestic thermosyphon solar water heater under varying operating conditions

An experimental investigation has been carried out on a thermosyphon solar water heater. The system consisted of a flat-plate collector of 1.5 m² absorber area with 21 tubes/m width and storage tank of 125 litre capacity. Experiments were carried out for both cloudy and clear weather conditions in winter and summer. The hourly system performance was evaluated for all test conditions. The final mean tank temperature was measured daily which enabled the calculation of the possible contribution of solar energy for domestic hot water supply in Basrah, Iraq (latitude 30.76°N). The system was tested at both no-load and loading conditions. Intermittent and continuous load was imposed, and system performance was evaluated for each condition.     

改性材料电热元件应用于电热锅炉的研究

本文对用一种新型改性材料作为电热锅炉的加热元件进行了研究 ,并对影响该电热元件热力性能的各类因素作了较详尽的分析和探讨 ,提出了优化设计方案 ,旨在为电热锅炉电热元件的研究和设计提供理论依据。     

Theoretical and experimental investigations of a two-phase thermosyphon solar water heater

This article experimentally and theoretically investigates a two-phase thermosyphon solar water heater. The performance of this innovative solar water heater at different solar radiation intensities and tilt angles are experimentally discussed. The results show the best charge efficiency of the system is 82%, which is higher than the conventional solar water heaters. The theoretical model is also developed using the thermal resistance-capacitor method. The simulation predictions agree well with the experimental data within an average error deviation of ±6%. Two methods for improving the performance of this heater, double fin tubes and nano particle, are proposed. The results show that charge efficiencies can increase 3% and 4%, respectively, according to the theoretical model.     

Year-round performance of an improved collector-cum-storage type solar water heater

Systematic studies have been carried out on collector-cum-storage type solar water heaters, and efforts were made to minimise heat losses so that this type of water heater can be used for getting hot water at 40°–45°C for taking baths in the early morning hours of the next day. This paper reports year round performace, the performance equation and economics of this new improved solar water heater. This heater can supply 100 litres of hot water at 60°–70°C in the afternoon, and 40°–45°C temperature can be retained till next day morning. Its efficiency is 70.1%.