基于绝对水势图的粮仓远程智能通风测控系统

为了提高粮食仓储中通风作业的管理水平,并降低粮仓管理员的工作难度,该文提出了一种基于绝对水势图的粮仓远程智能通风测控系统的设计方案,采用物联网和Android技术着重研发了"粮仓智能通风系统",并详细阐述了该系统的软硬件框架、主要功能模块及操作流程。绝对水势理论是利用水势图进行粮仓机械通风作业管理和控制的方法。在绝对水势理论中,提出了3个通风窗口:降温窗口、降水窗口、调质窗口。每个窗口都对应着相应的通风作业模式。当气温状态点在绝对水势图中的位置进入到某一窗口区域中时,则进行相应的通风作业。相比原始低效的温湿度数据处理方法,该系统数据用图形化的方式展现,降低了粮仓管理员的工作难度,加快了工作效率,解除了对粮仓管理员工作地点的限制,并且,该系统实现了对粮仓的信息化、智能化和远程化控制。在该系统的控制下,装粮试验中的模拟仓通风效果良好,并已安全度过长春地区储粮危险期。研究结果为相关粮食仓储工作提供参考。

Remote intelligent measurement and control system for granary ventilation based on absolute water potential diagram

Abstract: In this paper, a design of 'intelligent remote monitoring and control system of the granary' based on the absolute water potential theory (AWPT) has been proposed, which is used to improve information and intelligence level of the granary, and reduce the granary administrator's work difficulty. "Granary Ventilation Intelligent Decision System" (GVIDS) is the realization of this design. GVIDS's program development relies on the Android and the 'internet of things' technology. Its hardware framework, software framework, the main function modules and operational processes are the main research contents in this paper. The essence of AWPT is "the management and control method of granary's mechanical ventilation using water potential diagram" proposed by Wu Wenfu et al., which is improved on the basis of the Wu model. In the AWPT, there are three ventilation windows: cooling window, precipitation window and quality adjustment window, and each window corresponds to its appropriate operation mode of ventilation. When using AWPT to guide granary ventilation, the position of the air-temperature-point in the 'absolute water potential diagram' is observed to determine the need for ventilation, which means that the administrator makes proper ventilation operation according to the ventilation window area that the air-temperature-point falls. The client APP (application) consists of five parts, which are "Information Profile" module, "Absolute Humidity Diagram" module, "Absolute Water Potential Diagram" module, "Associated Equipment" module and "Managing Log" module. The "Information Profile" module is mainly responsible for displaying the basic information of different granaries; the theoretical basis of "Absolute Humidity Diagram" module is the WU model. First, the client will obtain the latest temperature and humidity data collected from the database. Then, according to the new grain CAE equation and allowing ventilation condition table, calculate and judge whether the current situation needs ventilation. Finally, draw the balanced absolute humidity diagram and balanced relative humidity diagram on the client. Absolute Water Potential Diagram (AWPD) is mainly composed of four curves and one point: absolute potential line of the air, absolute adsorption water potential line of the grains, absolute desorption water potential line of the grains, saturated humidity line of the air, and saturated humidity point of the air (Q). In the AWPD, the area surrounded by the blue lines is the cooling window, the area surrounded by the red line is the precipitation window, and the area surrounded by the green lines is the quality adjustment window. Because the cooling operation and precipitation operation is sometimes performed at the same time, there will be an overlap of the cooling window and precipitation window. "Associated Equipment" module is used to display the current equipments associated with the state of the work, and the user can remotely control these equipments with the switch buttons. "Managing Log" module is used for displaying all of the granary operation logs. The client App has so many advantages, such as friendly interface, simple operation, wide adaptability and intelligent and remote control, and it would solve the problem of limited working place for the granary administrator. In the simulated granary loading experiment, the performance of this system is very good, and it should be promoted.