Automatic gas dynamic volumetric system for aquatic products' MA preservation

Abstract

As there are many links in the cold chain logistics process, which takes a long time, the processed aquatic products are easily damaged and deteriorated. And the growth and reproduction of microorganisms in aquatic products can be inhibited by MA (Modified Atmosphere) preservation, thus extending the shelf life of aquatic products. In this context, we have developed an automatic gas dynamic volumetric system for aquatic products' MA preservation. It can control the operation platform by a 4G network cell phone client and realize remote monitoring function. Particularly, there are the main contents and conclusions of the study: 1) Combined with MA preservation, intelligent control and network communication technologies, we overcame the difficulties of remote monitoring for gas dynamic volumetric. Then, according to MA preservation and automatic gas dynamic volumetric, we designed a logical structure of the system, including the specific distribution of the sensing layer, network transmission layer and application layer. 2) We established the mathematical model for the system based on the step response method, and designed the analog acquisition, control and gas dynamic volumetric system; In addition, in this system, we realized the gas dynamic volumetric based on the embedded PID control algorithm and mass flow controller; Then, we used 4G network for remote data transmission and 4G DTU as network data transceiver, and realized remote monitoring function of mobile client through cell phone terminal applet software. 3) The results were shown by testing the stability, accuracy and communication of the system: the gas concentration error of the system floated at ± 0.25% when the gas dynamic volumetric system was stable, which was 12 times more accurate than before, and the gas dynamic volumetric speed based on embedded PID control algorithm was increasing by approximately about 50%, which greatly improved the working conditions and production efficiency.