【作者】 姜珊；

【导师】 冯恩民；

【作者基本信息】 大连理工大学 ， 运筹学与控制论， 2012， 博士

【摘要】 本文对最优控制在微生物发酵生产1,3-丙二醇和空调系统冰蓄冷工程领域中的应用分别进行了探讨.在微生物发酵中,以批式流加发酵生产1,3-丙二醇的控制为设计目标,首先,前馈控制批式流加,同时碱的流加采用耦联方式,依数值优化结果和pH值耦联控制的优化计算,设计了控制策略；其次,探讨了非耦联控制,pH值根据传感器自动检测的逻辑控制；最后,根据微生物发酵的菌体生长特性与二氧化碳浓度的相关性,把微生物发酵过程分为对数生长期和稳定期两个阶段,进行了反馈控制批式流加的设计.此项研究得到了国家自然科学基金、“973计划”及“863计划”的资助.另外,本文还对空调系统冰蓄冷工程的最优控制进行了研究,空调系统中冰蓄冷工程的设计符合国家近些年提倡的节能减排的要求,通过建立冰蓄冷过程的非线性非光滑的混合整数规划,构造优化算法并应用于具体工程实例中,取得了良好的效果.冰蓄冷通过“削峰填谷”的方式,将空调用电从白天高峰期转移到夜间低谷期,均衡了城市电网负荷.降低了用户的运行费用.本文取得的主要研究成果如下：1.依刘重阳等人研究的耦联填料批式流加发酵的数值模拟结果,考虑自动控制的可实现性,提出了把优化甘油泵流速转化为固定流速、优化流加时间的控制策略;针对用甘油批式流加发酵生产1,3-丙二醇的工艺要求,从控制电路图、软件控制流程到上位软件进行了设计.2.针对非耦联发酵生产1,3-丙二醇的批式流加过程,依据该生物过程的动力系统最优控制的数值结果,设计了批式流加前馈控制和加碱泵根据pH值的变化进行的自动控制,分别从设计电路图、PLC程序设计到计算机监控系统进行了设计;之后又进-步讨论了甘油泵的反馈控制,批式流加过程中根据二氧化碳浓度的变化,流加过程分为对数生长期和稳定期两个阶段,批式流加的控制策略也分成两部分,在实验室现有条件下,进行了电控箱的设计,PLC程序的编写,上位软件的设计,此部分程序通过不断调试和修改,现已在实验室成功运行.3.以多周期多设备冰蓄冷系统运行的动态过程为主要约束,以设备运行状态等为离散优化变量,以设备流体流速等为连续优化变量.以系统运行总费用为目标函数,建立了非线性非光滑的混合整数规划,并论述了该规划问题最优解的存在性.依离散优化变量的有限性,把这个优化问题等价地分解成有限多个关于连续优化变量的线性规划,构造具体的优化算法,最后应用于一个实际冰蓄冷系统,表明了数学模型及优化算法等的正确与有效性,缓解了用电高峰的用电量,并降低了用户的运行费用.更多还原

【Abstract】 This dissertation investigates the application of optimal control on both microbial produc-tion of1,3-propanediol and ice storage engineering.Firstly, we consider the fed-batch culture by Klebsiella pneumoniae for production1,3-propanediol, which is controlled by feed-forward control, coupling with alkaline fed-batch. Control strategy based on numerical simulation with pH coupled control is designed to maximum the production. Secondly, uncoupling with alka-line fed-batch.pH value measured automatically with transmitter and logic control is taken into consideration. Finally, on the basis of multistage growing characteristic of bacterium and the concentration of CO2,the process of microbial fermentation is divided into two phases,which are logarithmic growth and stable phase.The optimal control strategy of fed-batch culture is designed with feedback control.The research is supported by the National Natural Science Foundation of China, the Major State Basic Research Development Program of China and the National High Technology Research and Development Program of China. In addition, optimal control strategy about ice storage engineering on air conditioning system is also considered. The optimal control on the ice storage air conditioning system is accord with the national re-quirement of energy saving and emission reduction.In this paper, a nonlinear and non-smooth mixed integer optimization model is built and an optimization algorithm is constructed to seek the optimal solution.Numerical results are implemented on a factual ice storage air condi-tioning system, which has got a good profit.Ice storage air conditioning system produces ice at night and uses it during peak periods for cooling.It is so called"cutting peak and filling trough".This reduces energy usage during the peak periods.So it can balance the load demand of electrical power network in the city. The main contributions obtained in this dissertation are summarized as follows.1.A fed-batch culture with coupled feeds of glycerol and alkali is considered. In order to the factual experiments.On the basis of the numerical solution,which is studied by Chongyang Liu,we propose an optimal control strategy of feeding instants under fixed feeding rate.Correspondingly, an automatic control system is designed according to the process requirement of the glycerol feed-batch culture production of1.3-propanediol, which involves the design of control circuit, flow control software and upper computer integrated control system.2.Based on the microbial production of1,3-propanediol in fed-batch culture with uncou-pling feeds of glycerol and alkali and the optimized numerical result of the dynamic system in microbial process, we explore an automatic control system to implement the optimal control strategy, in which fed-batch of glycerol is controlled with feed-forward control and alkalinity is controlled according to the pH transmitter. The designs of control diagram, PLC control program and supervisory computer control system are involved. Then the feedback control of glycerol pump is discussed.The fed-batch process is di-vided into logarithmic growing phase and stable phase according to the concentration of CO2.And the control strategy of fed-batch culture is divided into two subprograms. The control box, PLC programmed and supervisory computer control system are designed on the existing fermenter in the laboratory. The feedback control program,which was tested and modified for many times,has been running successfully.3.We considered the optimization of an multi-period and multi-equipment ice storage sys-tem.Taking the dynamic process of the ice storage system as constraint, a nonlinear and non-smooth mixed integer optimization model is built, with the running state of equip-ments as discrete optimal variables, the flow rate of fluid in the equipments as continuous optimal variables,and the total system running cost of the system as target function.The existence of solutions to the optimization problem is explored. Due to the finiteness of the admissible set of the discrete variables, the optimization problem is equivalently divided into a finite number of sub-optimization problems,which are of the form of linear pro-gramming with continuous variables to be optimized.An optimization algorithm is then constructed.Numerical results are implemented on an factual ice storage air conditioning system, revealing that both the power consumption at peak and the running cost for user are reduced considerably. So the mathematical model and optimization algorithm is valid.更多还原