基于MCU和CFD的鸡舍氨气检测装置设计与试验

为了准确测量肉鸡养殖过程中鸡舍内的氨气浓度，实现舍内氨气环境的精准调控，设计了一种由气体检测系统、气体循环系统和辅助装置构成的主动式氨气检测装置。装置通过控制风扇实现状态切换，使用电化学氨气模组检测气体，通过微控制器（Micro control unit，MCU）实现浓度数据分析、处理，并运用计算流体力学（Computational fluid dynamics, CFD）技术模拟装置在不同状态下的速度云图和速度矢量图，由此得到空气龄，确定单次进气时间。装置在氨气检测状态时气流呈逆时针循环流动，使氨气浓度更均匀，最大空气龄为0.804s，装置设定单次检测时间为1s，每10s检测一次，每6个值的均值作为1min的值。在养殖鸡舍内进行现场试验，结果表明本文装置检测的氨气浓度和氨气变送器检测值的Pearson相关系数达到0.832，与检测结果趋势相符，平均相差为3.46%，方差也较小，总体比氨气变送器检测值波动小，检测更稳定。该检测装置具有速度快、精度高和稳定性强等优点。

Design and Test of Ammonia Detection Device in Broiler Chamber Based on MCU and CFD

In order to accurately measure the ammonia concentration in the broiler chamber during broiler breeding and precisely regulate the ammonia environment in the chamber, an active ammonia detection device, which was composed of a gas detection system, gas circulation system and auxiliary device, was designed. The device realized state switching by controlling the fan. The electrochemical ammonia module was used to detect the ambient gas. After the concentration data were analyzed and displayed by STM32 micro control unit (MCU), computational fluid dynamics (CFD) technology was used to simulate the velocity nephogram and velocity vector diagram of the device in different states. The time of each intake was determined by air age. In ammonia detecting, the air flow presented a counterclockwise circulation flow, which can make the ammonia concentration more uniform and the measurement results more accurate. The airflow velocity in the device was mostly about 2m/s and the maximum air age was 0.804s, so the single detection time was set to 1s. The device detected 6 times per minute and then took the mean value as the minute value. Through the field test in the broiler chamber, the results showed that the Pearson correlation coefficient between the ammonia concentration values detected by the active ammonia detection device designed and the ammonia transmitter was 0.832, which showed that the detected results were basically consistent, with an average difference of 3.46%. Generally, the fluctuation was smaller than that of the ammonia transmitter, and the measured value was more stable. The detection device had the advantages of fast speed, high stability, and low power consumption. It can be used as an ammonia detection device in the broiler chamber, and also can provide a theoretical basis and reference for the development and improvement of ammonia detection devices in the broiler chamber and other poultry houses.