为了能从众多多效蒸发流程中快速准确地筛选出能耗最低的最佳流程,建立了筛选多效蒸发最佳流程的新方法——矩阵法.新方法将多效蒸发系统中的物料衡算和热量衡算非线性方程组描述成矩阵方程,当流程或节能措施改变时,无需重新推导数学模型,只需将矩阵方程中的若干参数重新赋值,模型就能模拟并流、逆流、各种形式的错流、平流和平错流,还能模拟上述流程有或无蒸汽喷射式热泵技术、引出额外蒸汽预热原料液、冷凝水闪蒸和溶液闪蒸的各种情况,从而快速准确地筛选出最佳流程.浓缩菠萝汁的三效蒸发系统的模拟筛选结果表明:不采用任何节能措施或仅采用冷凝水闪蒸或仅采用蒸汽喷射式热泵技术时,最佳流程是逆流;同时采用蒸汽喷射式热泵技术、引出额外蒸汽预热原料液和冷凝水闪蒸的并流流程最佳,其节省的生蒸汽消耗量高达42.77％.矩阵法是筛选多效蒸发最佳流程的新方法,具有通用性强、效率高、速度快且准确等突出优点.

A general and rigorous mathematical model is developed for a multiple effect evaporator system which includes various energy reduction schemes (ERSs). These ERSs are thermal vapor compression, vapor bleeding, condensate flashing and solution flashing. The model can achieve the function of pumping steam at any effect and can work as an effective screening tool for the selection of optimal feed flow sequence (OFFS). In order to solve the model, the iteration method combining with matrix methods is proposed. To study effect of different ERSs on steam consumption (SC), an example of the co-current quadruple effect evaporator system is considered. These schemes can reduce the SC up to 46.56% if the feed is heated up to 88 degrees C and ejection coefficient at 3rd effect is set to 0.3. The OFFS is forward sequence as long as preheating temperature is high enough when constraints of heat transfer driving force can be satisfied. (C) 2016 Elsevier Ltd. All rights reserved.

为了探寻一种分离乙醇-碳酸二甲酯(简称DMC)二元共沸物的高效节能新工艺,首先在Aspen Plus软件平台上建立了分隔壁萃取精馏塔(简称EDWC)分离乙醇-DMC的三塔等效新工艺流程,然后采用单变量灵敏度分析法模拟新工艺中6个可调设计变量对新工艺分离效果和能耗的影响规律,并分析得到它们的最佳值,最后在最佳设计和操作条件下模拟新工艺,结果表明,对相同的分离任务和要求,新工艺与文献已报道的双塔工艺流程相比,前者的再沸器能耗比后者节省高达43％,而设备投资比后者更少.EDWC是分离乙醇-DMC共沸物的既高效节能又节省设备投资的新工艺.

为了大幅减少果汁蒸发工艺的能耗,创新设计了一种结合蒸汽喷射式热泵技术和引出额外蒸汽预热果汁两种节能措施的果汁低温热泵并流多效蒸发系统,建立了用矩阵方程描述的该系统的数学模型,研究了求解该模型的算法即迭代法结合矩阵法.浓缩橙汁的低温热泵并流3效蒸发系统的模拟结果表明,将橙汁预热至70℃,热泵的喷射系数设置为0.7、抽汽位置设置在第2效时节省的生蒸汽消耗量高达46％左右.采用上述两种节能措施的低温热泵并流多效蒸发系统在最佳的热泵喷射系数和抽汽位置的条件下是高效节能的,特别适用于果汁等热敏性溶液的蒸发.

为了大幅降低蔗糖厂蒸发工艺的能耗,首次将蒸汽喷射式热泵技术、冷凝水闪蒸和引出额外蒸汽预热糖汁等3种节能措施,同时运用于糖汁浓缩并流多效蒸发系统中,并建立了用矩阵方程描述的该系统的数学模型.模型具有很强的通用性,可实现上述节能措施的自由组合和热泵在任意效抽汽的功能,还可推广用于食品工业其它热敏性溶液的蒸发浓缩;模型存在最佳的热泵喷射系数和抽汽位置,同时采用上述3种节能措施且在最佳条件下可以高效节能.用迭代法结合矩阵法求解浓缩糖汁的热泵并流四效蒸发系统的模型,结果表明,同时采用上述3种节能措施,并在满足约束条件的前提下,将糖汁预热至90℃,热泵的喷射系数为0.5,抽汽位置在第2效时节省的生蒸汽消耗量高达41％左右.

为了降低海水淡化过程的能耗,首次建立了同时包含蒸汽喷射式热泵技术、引出额外蒸汽预热海水和冷凝水闪蒸等3种节能措施的海水淡化热泵并流多效蒸发系统的数学模型,并用矩阵方程的形式描述该模型,具有很强的通用性,可简化为具有不同节能措施组合或无节能措施的并流多效蒸发模型,还可实现热泵在任意效抽汽的功能.用收敛速度快的迭代法结合矩阵法模拟求解海水淡化热泵并流9效蒸发系统,结果表明同时采用上述3种节能措施,且在满足相关约束条件下,使海水的预热温度尽可能高,使热泵的喷射系数和抽汽位置均为最佳值时该蒸发系统是高效节能的,节省的生蒸汽消耗量最高可达16.72％左右.

Cuckoo Search ( CS) is a novel meta-heuristic algorithm. Aiming at the defects of weak local search ability,slow convergence velocity and low convergence accuracy,a modified CS algorithm based on DFP and adaptive step is proposed in this paper. In the im-proved cuckoo search algorithm,the step of Lévy flight nonlinear dynamic changes improve convergence velocity. After evolved from Lévy flights and elimination mechanism,the cuckoo populations rapidly access to global minima by DFP. Sixth representative benchmark functions are used to test the performance of DACS algorithm and CS algorithm respectively. The conclusions indicate that DACS algo-rithm has faster convergence speed,higher convergence accuracy and robustness,compared with CS algorithm. Meanwhile,DACS algo-rithm keeps strong global search capability,which is particularly suitable for the optimization of multimodal function and high dimension function.

为了全面提升布谷鸟搜索算法(CS)的性能,提出了一种改进的布谷鸟搜索算法(MCS).MCS算法采用了能大幅提高局部搜索能力的局部搜索策略、能使步长控制因子随算法进程由大到小自适应变化的自适应策略和能加强布谷鸟个体间信息交流的学习策略.2个标准测试函数被用于检验算法的性能,性能测试结果及对比试验表明,MCS算法在继承了CS算法强大的全局寻优能力的同时,具有更快的收敛速度、更高的收敛精度和更好的鲁棒性.最后,将MCS算法应用于求解多效蒸发系统的优化设计问题,优化效果显著.

为了降低错流多效蒸发过程的能耗,将蒸汽喷射式热泵技术运用到错流多效蒸发系统中,并将系统中的物料衡算、热量衡算方程组用矩阵方程的形式描述,使所建立的热泵错流多效蒸发模型具有较强的通用性.用收敛速度快、稳定性好的迭代法结合矩阵法模拟求解热泵错流四效蒸发模型,结果表明.蒸汽喷射式热泵技术具有较明显的节能效果,热泵的喷射系数越大,或热泵的抽汽位置越往后效,节省的生蒸汽消耗量越大,节能效果越好,但同时蒸发器的传热面积也越大,存在最佳的热泵喷射系数和最佳的热泵抽汽位置.

为了大幅降低错流多效蒸发过程的能耗,首次将蒸汽喷射式热泵技术、冷凝水闪蒸和溶液闪蒸等3种节能措施同时运用到错流多效蒸发系统中,并建立了用矩阵方程描述的该系统的数学模型.模型具有很强的通用性,可实现热泵在任意效抽汽的功能,可简化为只有其中若干种节能措施组合或无上述节能措施的错流、并流、逆流多效蒸发系统的模型.在满足约束条件的前提下,模型存在最佳的热泵喷射系数和抽汽位置,同时采用上述3种节能措施且在最佳条件下模型是高效节能的.浓缩氢氧化钠溶液的热泵错流五效蒸发系统的模拟结果表明,当热泵的喷射系数为0.15、抽汽位置在第2效,采用冷凝水闪蒸和溶液闪蒸时系统节省的生蒸汽消耗量高达32.51％.

In order to greatly reduce the energy consumption of fruit juice concentration process, a general mathematical model of countercurrent multiple effect evaporation (MEE) system contains various energy saving measures simultaneously (such as steam jet heat pump technology, solution flash and condensed water flash) is established in this paper. The systematic material balance equations and heat balance equations are described as the form of matrix equation to realize the generality of this model. The general model can be simplified to a countercurrent multi-effect evaporation model contains several or none energy saving measures and it can achieve the function of pumping steam at any effect. The model is solved by matrix method combining with iteration method, which has advantages of less sensitive to initial values, high convergence speed and stability. The developed model is used to simulate the fruit juice concentration process under different operating strategies. The simulation results indicate that heat pump is an effective energy saving measure in countercurrent MEE system. The larger values of ejection coefficient and effect for pumping, the more fresh steam consumption saves and heat transfer area increases when some constraint conditions are satisfied. After combining condensed water flash and solution flash, it achieves a more pronounced effect. (C) 2014 Elsevier Ltd. All rights reserved.

In order to make the Cuckoo Search algorithm maintaining the strong global Search ability, meanwhile improving the local Search ability as much as possible, the parameter ofβwhich affecting Step length of the search path and the fraction (pa) of the egg laid by a cuckoo abandoned change from fixed value to dynamic parameters which adaptive changing along with the search process on the basis of in-depth analysis of mechanism of CS algorithm. In addtion the nests of cuckoo that crossing the border are made to build new nests around the best nest instead of building new nests in the border to improve the local search ability and convergence speed of the algorithm.The improved CS algorithm called adaptive cuckoo search algorithm (shortened form ACS algorithm).The ACS algorithm and CS algorithm are tested by eight standard test functions. The conclusions indicate that whether a simple unimodal function, or complex multimodal functions, whether the small low-dimensional function or large high-dimensional function,the optimization performance of ACS algorithm are better than CS algorithm.

为了大幅降低海水淡化过程的能耗,将蒸汽喷射式热泵技术引入海水淡化多效蒸发系统中,并建立带热泵的海水淡化并流多效蒸发系统的模型,用迭代法结合矩阵法求解该模型,结果表明蒸汽喷射式热泵技术具有较明显的节能效果,热泵的喷射系数越大,或热泵的抽汽位置越往后效,节省的生蒸汽消耗量越大,节能效果越好,但同时蒸发器的传热面积也越大,在满足约束条件下存在最佳的热泵喷射系数和最佳的热泵抽汽位置.

To do further research on the mass-transfer mechanism in rotating packed bed (RPB), dynamics of droplets in a RPB are studied by an analytical approach combined with a series of laboratory measurements. Based on the results of the fluid dynamics, mathematical models of mass-transfer coefficient and mass-transfer process in RPB are proposed, respectively. Mass-transfer experiments in RPB are also carried out using ethanol–water solution. By comparison, the results of simulation agree well with that of the experiment, which demonstrate that both hydrodynamic model and mass-transfer models can better describe the real conditions of RPB. © 2014 American Institute of Chemical Engineers AIChE J , 60: 2705–2723, 2014

In order to reduce energy consumption and enhance economic benefit , on the basis of building a simulation process of four columns equivalent model of dividing wall column (DWC) for separating pinene from turpentine by Aspen Plus, and confirming the design variables that influence energy consumption and separation effect strongly, as well as their search scopes by sensitivity analysis, the multi-objective optimization model of dividing wall column for separating pinene from turpentine was established where the objectives were to minimize the total number of stages in prefractionator and main column as well as the heat duty. Constrained MOPSO (CMOPSO) algorithm was used to solve the multi-objective optimization model. The results indicated that CMOPSO algorithm could obtain good Pareto front of DWC which provided decision makers with a variety of alternative optimization design schemes of DWC. Compared with single objective optimization results, the multi-objective optimization of DWC separation process could further save energy 21.7 kW under the similar total number of stages (or equipment investment cost). Vapor and liquid split fraction were special and important design variables of DWC, and by the use of bivariate sensitivity analysis, their suitable value ranges were confirmed accurately, which was able to further reduce the searching time when vapor and liquid split fraction values were searched in these ranges.

Cuckoo search algorithm is a novel stochastic global optimization algorithm based on swarm intelligence,with advantages of few control parameters,optimal search path and good global search capability,but it also has shortcomings of weak local search ability,slow convergence velocity and low convergence accuracy.In order to overcome these disadvantages of CS algorithm,an improved cuckoo search algorithm based on conjugate gradient is introduced.After evolved from Levy flights and elimination mechanism,the cuckoo populations decline rapidly in the mutually conjugate directions so that the convergence ability of algorithm is strengthened significantly under the condition of maintaining the strong global search capability of CS algorithm.The CGCS algorithm and CS algorithm are tested by four typical test functions.The conclusions indicate that CGCS algorithm has faster convergence velocity,higher convergence accuracy and more stable optimization results.Meanwhile CGCS algorithm has good global search capability,convergence ability and robustness,which is particularly suitable for the optimization of multimodal function and high dimension function.

A novel process was proposed for the separation of α-pinene and β-pinene from turpentine,in which a dividing wall column was adopted instead of the conventional distillation column.To choose the structure suitable for turpentine mixture,three types of divided wall distillation columns were simulated with the software of Aspen plus.Results shows that,compared with the conventional distillation process,DWC could save energy 26.0%,DWC-SS could save energy 16.6%,DWC-SR could save energy 12.5%.And the effect of feed stage,feflux ratio,interconnection stage,side product stage,and distribution ratio of vapor and liquid on the separation efficiency and reboil duty were investigated especially through sensitive analysis,then the main parameter of the column was determined.

A novel experimental method is proposed to investigate the fluid flow in rotating packed beds (RPB). Experimental results show that the novel method is simple and effective and can be used not only in the lab experimental equipment but also in the industrial grade equipment. By using this method, the hydrodynamic performances of the RPB can be easily studied, which include actual wetting and false wetting, the flow pattern of the liquid film flow, the number and width of liquid trajectories, etc., and consequently, their changing rules are obtained. The results have significant effect on the gas-liquid two phase transfer behavior and are the basis of establishing accurately hydrodynamic mathematical model for RPB.

The purpose of the study is to deeply understand the influence factors and laws of transient startup process of batch distillation in rotating packed bed(RPB) which is packed with triangular spiral packing. The batch distillation experiments were done with ethanol-water system at atmospheric pressure and under the total reflux conditions. The rotational speed ranged 450 rpm from 1050 rpm, which provided centrifugal forces a great many times than the Earth's gravity. By means of changing the feed concentration, rotational speed and heating power, experimental results indicate that the transient startup process is greatly enhanced in terms of shortening time and saving energy. The startup process in our study only needs about 30 minutes and the concentration of distillate is high(nearly the azeotropic mixture of the ethanol-water system). Comparing with the conventional column in the gravitational field, the startup process in RPB is not a time-consuming process. Consequently, the concentration of distillate which increases with the feed composition and the heating power of reboiler comes up to maximum under the optimal rotational speed. An unusual result is also noted that the startup process of batch distillation in RPB with different feed composition should operate under the higher heating power of reboiler and the corresponding optimal rotational speed conditions in practical production process. Therefore, the batch distillation transient startup process in RPB has the best effect under the optimal rotational speed and higher heating power. The results indicate that the startup process of batch distillation in RPB is greatly intensified, which places an important role in the process of product removal in terms of shortening period of operation, enhancing produce capacity and saving energy, etc. Moreover, the mathematical model based on the equilibrium stage theory was built to describe the laws of transient startup of batch distillation in RPB. The average relative error between simulative value and experimental data of the mass fraction of ethanol in distillate and the temperature of overhead vapor are only 0.4% and 0.08%, respectively. The comparison results prove the accuracy and commonality of the model. So the rotating packed bed is an effective way to strengthen the batch distillation process, which is flexible and convenient to manipulate and is expected to apply in industrial process. Fundamental performance characterizations and more generalized theoretical expressions for parameters of batch distillation in RPB that accurately predict batch distillation performance in RPB will be needed to confidently scale-up this application.

The training on engineering ability and innovative sense has been running throughout the culturing of chemical engineering professionals by exploration and practice.The mode of chemical engineering education accompanied with engineering oriented quality training is preliminarily formed,which enables students to benefit from the reform of higher engineering education.