Spatiotemporal distribution characteristics of environmental parameters of centralized ventilation delivery sows based on WSN

In order to study the spatial and temporal distribution characteristics of various environmental parameters of centralized ventilation in pigsties, a centralized ventilated delivery house by numerical simulation in Yunnan province was taken as the test object, and a wireless multi-source and multi-point remote monitoring system (Wireless Sensor Network, WSN) was used to carry out the environmental parameter monitoring test and statistical analysis on the breeding environment of the delivery pigsty. Experimental results showed that during the period of experiment, there were significant differences in temperature between different time periods in the delivery pigsty (P<0.05, the average temperature of Time: 00:00-06:00, 06:00-12:00, 12:00-18:00 and 18:00 - 00:00 was 22.98, 23.78, 24.44 and 23.61 ℃), the time periods of 00:00-06:00 and 12:00-00:00 were significantly different from other time periods respectively. There was no significant difference in relative humidity and CO2 concentration between 12:00-18:00 and 18:00-00:00, but they were significantly different from the other two time periods. The change of NH3 concentration was significant only during the time period from 12:00 to 18:00 (P<0.01). There were significant differences in the temperature variation among the three areas inside the delivery pigsty (P<0.05), and the average temperature in the area with 35cm horizontal height was the highest (24.26 ℃) and the most stable (CV=2.14%). There were no significant difference in the change of relative humidity with horizontal height of 90 cm and 35 cm.. The distribution of NH3 and CO2 concentration in the three areas of the delivery pigsty was also divided into three groups, with significant differences among them (P<0.01). Relative humidity and temperature changed over time negative correlation, the temperature in each area of the piggery can be controlled below a high critical level, the peaks of the relative humidity was 82.31%, the temperature field distribution uniformity was better than humidity field, and the distribution of NH3 concentration was more uneven than that of CO2. NH3 concentration could be effectively maintained at a low level in the delivery pigsty, the concentration in each monitoring area was far less than the index value (20 mg/m3), but the concentration of CO2 was at a high level both in time and space. In the plane with a height of 90 cm, the temperature distribution was high in the middle and low in the four sides. The relative humidity tended to be average values in the left area, and the lowest in the right side wall area. NH3 and CO2 would appear to accumulate at the corner. The temperature humidity index was low, the peak point of average THI (Temperature-humidity Index) inside was 75.30, and the probability of heat stress of pigs was low. In this study, Wireless Sensor Network system was used to conduct remote monitoring of environmental parameters of piggery from multiple sources and multiple points, and the distribution characteristics of environmental parameters of centralized ventilation piggery were analyzed, which provided a reference for the optimal design of environmental control of farrowing house under this ventilation mode.