自然冷源保鲜库保鲜系统的设计

发布时间：2018-08-09 18:36

【摘要】：随着果蔬产业的不断发展,人们对果蔬的需求量及其品质要求同步增加。果蔬难储藏,易腐烂,保鲜库能有效减少果蔬储藏过程中的损失。为了确定果蔬保鲜储藏的最佳环境条件,实现果蔬储藏后仍能保持最佳品质,结合沈阳市科技计划项目"寒富苹果的可移动式自动测控与预报储藏保鲜库的研发"的内容,本文对实际保鲜库进行数值模拟计算分析,并设计了适合保鲜库的无线温湿度监控系统,以寒富苹果为对象进行了储藏试验研究,研究内容与结论如下。(1)果蔬保鲜库保鲜技术、数值模拟技术及无线监控系统现状分析。在对果蔬保鲜库保鲜技术发展现状分析的基础上,对数值模拟及温湿度无线监控系统的技术进行研究,提出采用数值模拟与温湿度无线监控系统技术相结合的方法,改善果蔬保鲜库的储藏环境,提升果蔬储藏品质。(2)保鲜库结构设计及数值模拟分析。在对保鲜库结构设计的基础上,对库体内三种不同苹果箱摆放方式的速度场进行模拟分析,得到不同位置不同方向的二维速度矢量图。结果表明:苹果箱之间前后间隔3cm,左右间隔5cm的摆放方式,库内气流分布均匀且有大回流漩涡,有利于保鲜库库内降温,并可以有效散失苹果箱内因苹果呼吸作用而产生的热量。(3)保鲜库无线温湿度监控系统设计。设计基于nRF24L01+无线通信模块的温湿度监控系统,系统包括监测控制单元、数据传输单元及上位机监控单元,软件设计采用模块化编程思想,实现主程序调用各模块的子程序。通过硬件系统的设计及软件系统编程,能够实现保鲜库温湿度环境参数的无线准确监控。除了主要的温湿度监控功能,还实现在保鲜库库外就可观察库内的温湿度数据,减少了操作人员对保鲜系统内部的干扰,方便操作人员观察库内温湿度数据。(4)保鲜库系统运行及保鲜品质验证。将从沈阳农业大学寒富苹果科研基地采摘的寒富苹果,按照数值模拟的结果进行合理摆放,并运行无线温湿度监控系统,进行系统运行效果测定试验和保鲜品质试验。结果表明:与温湿度记录仪测得的温湿度数据比较,无线温湿度监控系统下的温湿度最大误差分别为±0.2℃和0.4%,温湿度能控制在要求的误差范围内,满足实际储藏要求;保鲜库保鲜系统运行10周后,寒富苹果的平均失重率为1.9%,果皮和果肉色差分别增长11%和8%,整体咀嚼性及果肉咀嚼性分别下降了18.59%和21.53%。说明该保鲜库系统长期运行状态稳定,寒富苹果经储藏后,苹果品质较好。
[Abstract]:With the development of fruit and vegetable industry, the demand and quality of fruit and vegetable are increasing. The storage of fruits and vegetables is difficult to store and easy to rot, and the storage can effectively reduce the loss of fruits and vegetables during storage. In order to determine the best environmental conditions for preservation and storage of fruits and vegetables, and to keep the best quality of fruits and vegetables after storage, the contents of Shenyang's scientific and technological project, "Research and Development of movable automatic Control and Prediction Storage Storage of Cold Rich Apple", were introduced. In this paper, the numerical simulation and analysis of the actual storage storehouse are carried out, and the wireless temperature and humidity monitoring system suitable for the storage storehouse is designed, and the storage experiment is carried out with the cold rich apple as the object. The research contents and conclusions are as follows: (1) the preservation technology of the fruit and vegetable preservation storehouse. Numerical simulation technology and wireless monitoring system status analysis. Based on the analysis of the current situation of preservation technology in fruit and vegetable storage, the technology of numerical simulation and wireless monitoring system of temperature and humidity is studied, and the method of combining numerical simulation with wireless monitoring system of temperature and humidity is put forward. Improving the storage environment and improving the storage quality of fruits and vegetables. (2) structure design and numerical simulation analysis. On the basis of the structural design of the storage room, the velocity field of three different apple boxes in the storage room was simulated and analyzed, and the two-dimensional velocity vector diagram with different positions and different directions was obtained. The results showed that the arrangement of 5cm between the apple boxes was 3 cm, and the airflow distribution was uniform and there was a large backflow whirlpool in the storage, which was beneficial to the cooling of the storage. And it can effectively lose the heat produced by apple respiration in the apple box. (3) the design of wireless temperature and humidity monitoring system. The temperature and humidity monitoring system based on nRF24L01 wireless communication module is designed. The system includes monitoring control unit, data transmission unit and host computer monitoring unit. The software design adopts modular programming idea to realize the main program calling each module subroutine. Through the design of hardware system and the programming of software system, the wireless and accurate monitoring of temperature and humidity environment parameters can be realized. In addition to the main functions of temperature and humidity monitoring, we can also observe the temperature and humidity data in the storage outside the storehouse, thus reducing the interference of the operators to the preservation system. Convenient operators to observe the temperature and humidity data. (4) Storage system operation and quality verification. According to the results of numerical simulation, the apple picked from the scientific research base of Hanfu apple of Shenyang Agricultural University will be arranged reasonably, and the wireless temperature and humidity monitoring system will be run, and the system operation effect and fresh-keeping quality test will be carried out. The results show that compared with the temperature and humidity data measured by the temperature and humidity recorder, the maximum error of temperature and humidity under the wireless temperature and humidity monitoring system is 卤0.2 鈩，

本文编号：2174947