节点文献
船舶空调系统的建模与仿真
Modeling and Simulation of the Marine Air Condition System
【作者】 何治斌;
【导师】 张均东;
【作者基本信息】 大连海事大学 , 轮机工程, 2011, 博士
【摘要】 船舶空调系统是船舶的重要辅助设备,是设备正常运行的保障,能够有效改善人们生活和工作环境,以及卫生条件。建立能准确反映船舶空调系统的数学模型对系统的运行控制、仿真和性能分析,以及实验室的建设都有重要意义。制冷系统的稳态仿真技术已趋于成熟,但螺杆冷水机组制冷系统动态模型的研究还在发展、完善中。而且近年来国内外发生的许多船舶机损和船损事故大多是由人为失误和错误造成的,这迫切需要通过积极的询问和评价、连续不断对情境进行分析和监控、必要时采取果断行动等方法,来提高情景意识。基于此,本文以“育鲲”教学实习船的船舶空调系统为参考对象,通过用分布参数模型建立蒸发器和冷凝器数学模型、用集中参数模型建立压缩机和膨胀阀数学模型的方法,建立了冷水机组的数学模型,然后又基于热力学和传热学定律,通过建立PID三通电磁阀控制的冷却水与空气的热量传递关系,以及船舶供冷负荷关系,建立了夏季制冷除湿工况的空气处理系统模型,又通过建立PID三通电磁阀控制的蒸汽与空气的热量传递关系,以及船舶供热负荷关系,建立了冬季加温加湿工况时的空气处理系统模型,最后联立建立了船舶空调系统总模型的矩阵方程式。求解模型方程时,通过引入冷凝器进口制冷剂焓值hci为未知量,将密度的求导转换为对hci和冷凝温度的求导,避免了hci和密度求导时对多个变量求导的情况,简化了求导过程,再通过采用冷剂温度、压力、比容和比焓的拟合关系求取矩阵系数,以及用多变量函数的Taylor幂级数展开式代替原函数方程的方法,降阶线性优化方程,简化了模型状态方程系数求导过程。然后以Matlab为仿真工具,进行了仿真计算,与实船测试数据进行了对比分析,验证计算精度和仿真实时性有很大提高。本文详细分析了“育鲲”轮空调系统3套冷水机组、6台压缩机、3套冷媒水泵、6只膨胀阀等设备的启动控制,风机、冷却水泵与压缩机的连锁启动控制,压缩机的滑油低压、冷却水高温、冷却水低压报警,以及空气调节系统通风、制冷和制热控制的PLC程序和操作流程,并以此逻辑关系和条件为基础,基于VS.net通过建立龙格库塔解微分算法,调用船舶空调系统的数学模型,开发控件的方法,研发了船舶空调模拟器仿真软件。该软件功能完善,可以手动和自动操作系统设备,能依据空调室温度和设定温度的偏差来控制冷却水三通阀或蒸汽加温阀的开度,依据空调室湿度和设定湿度的偏差来控制蒸汽加湿阀的开度,可自动和手动调节冷却水三通电磁阀、加温电磁阀和加湿电磁阀的PID参数,并且能设置故障和更改系统变量,模拟故障发生后的压力、温度等参数变化情况;而且界面友好,可实时显示后台模型计算出的空气处理系统的新风、回风和供风的温度、湿度,以及冷水机组的的蒸发压力、冷凝压力等重要参数。基于3ds Max和Virtools三维仿真软件实现了压缩机、换热器、风机等设备和管系的三维建模,以及船舶空调室和冷水机组舱室三维视景的实时漫游,并通过C语言套接字的方法实现了三维场景和二维仿真软件之间的通讯和交互,可以在二维和三维场景中实现对空调设备的操作,并同时显示设备运行情况、按钮、旋钮指示灯等状态。最后依据某高校空调实验室的建筑结构特点,根据热力学和传热学定律,计算出房间夏季供冷负荷的制冷量和冬季供热负荷工况的制热量,并依此确定了匹配的压缩机型号、冷却水箱容积、冷却水泵排量和加热器功率,设计和编写了包括连锁保护和报警功能的逻辑控制程序,现场组织施工完成了空调实验室的建设。
【Abstract】 The ship’s refrigeration and air conditioning systems is a major ship auxiliary equipment, protection of the normal operation of the device, and can also improve people’s living environment, working condition, as well as health situation. Accurately mathematical modeling of marine refrigeration and air conditioning system is very impprtant to the system operation control, simulation and performance analysis, and laboratory construction. The refrigeration system’s stable state emulation technique is mature, but screw water chiller refrigeration system dynamic model is developing and imperfect. Moreover, in recent years, lots of domestic and foreign accidents about machine damage and ship damage are caused mostly by the artificial mistakes and errors, this needed to raise the scene consciousness urgently through the methods of actively inquire and evaluate, analysis and monitor to the situation continuously, and take decisive action if necessary.Based on this, the mathematical model of the water chiller is established, by the method of taking the refrigeration and air conditioning system of the wheel "Yu Kun" as the reference object, building the distributed parameter model of the evaporator and condenser, and the concentrated parameter model of the compressor and expansion valve. The summer ventilation system model of cooling and dehumidification is built through establishing heat equations of the cooling water controlled by three-way solenoid valve and the air, and cold load equation of the air-conditioned room, and the winter ventilation system model of warming and humidification is built through establishing heat equations of the steam controlled by three-way solenoid valve and the air, and heat load equation of the air-conditioned room, according to thermodynamics and heat transfer theory. At last, the matrix equation of the ship’s refrigeration and the air-conditioning system general model is established by associating equations.The derivation process is simplified by supposing the enthalpy of refrigerant at condenser’s import an unknown variable, converting the derivation of the density to the derivation about the variable hci and the condensing temperature, which avoiding to derivate about several variables, and the equation is reduced, lined and optimized, derivation process of state coefficient is simplified through the method that calculating matrix coefficients using relationships among refrigerant temperature, pressure, specific volume and enthalpy, and replacing the original function equation with multi-variable function’s Taylor power series expansion equation. Then simulation and calculation is carried on, and compared analysis is took with the ship’s test data basing on Matlab a simulation tool, which verifying that the accuracy and real-time simulation has greatly improved.The PLC Procedure and operating flow is analyzed, which including starting control about 3 chiller units,6 compressors,3 chilled water pumps,6 electronic expansion valves, Interlocking control about fans, cooling water pump and compressor, alarm about compressor low oil pressure, cooling water high temperature, cooling water low pressure, programming control about ventilating model, cooling model and heating model of the air conditioner. Based on VS.net, and taking the above logical relations and conditions as the basis, the marine refrigeration and air conditioning simulator simulation software is researched and developed, by establishing Runge-Kutta differential solution algorithm, calling the air-conditioning system’s mathematical mode, and developing module. The software is fully functional, system equipment can be operated manually and automatically, cooling water three-way valve or warming steam three-way valve is controlled according to the deviation between the air-conditioned room temperature and the setting value, humidifying steam valve is controlled according to the deviation between the air-conditioned room humidity and the setting value, the PID parameter of cooling water three-way electromagnetic valve, warming solenoid valve and humidifying solenoid valve can be adjusted automatically and manually, the fault and variable can be set and changed, and the pressure, temperature and other parameters can changed really according to the simulated failure; Furthermore, the simulator’s interface is friendly, the temperature and humidity of the ventilation system’s fresh air, return air and supply air which calculated from background model, and the evaporation pressure, condensing pressure and other important parameters of the water chillers can be displayed.Based on three-dimensional simulation tool 3ds Max and Virtools, the three-dimensional model of the compressor, the heat exchanger, the fan, other equipment and the pipe is built, and real time roaming of three-dimensional scene about air conditioner cabin and chiller compartment is implemented.Through the sockets of C language, communication and interaction between the three-dimensional scene and two-dimensional simulation is achieved, air conditioning equipment can be operated simultaneously in the two-dimensional and three-dimensional scene, and the running situation of device, switch station of the button, knob, and lights can be displayed consistently.Finally, the cooling capacity of the summer’s cooling load and the heat capacity of the winter’s thermal load conditions in the room is calculated, according to a university refrigeration and air-conditioning laboratory building structure’s characteristics, and according to the thermodynamics and heat transfer theory. And so, the compressor type, cooling water tank volume, cooling water pump displacement and the heater power which matching the condition is chosen, the logic control program including protection and alarm function is designed and compiled, the laboratory of the ship refrigeration and air conditioning system is constructed.
【Key words】 Refrigeration and air conditioning; Dynamic model; Simulator; Virtools; Virtual simulation; Laboratory design;