Monitoring system for brine well in production of potash fertilizer based on wireless sensor network

Abstract: Underground brine of Qinghai Saline Lake, which contains many kinds of mineral deposits such as potash, magnesium, sodium, and lithium, is a kind of important raw material for chemical products such as salt, potash fertilizer, and lithium carbonate. The pumps are easily prone to be out of order due to the fact they must keep running around the clock in a complicated climate environment around the saline lake mining sites. However, traditional monitoring for the chemical brine pump in Qinghai Saline Lake is a manual monitoring technology with high cost, non-real time, inflexibility and high energy consumption. This paper proposed a remote monitoring system based on the wireless sensor network (WSN) for the brine well in the production of potash. It consists of 2 units: one is real-time monitoring unit based on WSN with ZigBee protocol and CC2530 wireless sensor SoC, and the other unit is remote management information system (RMIS) of brine well based on a PHP (Hypertext Preprocessor) software platform. The real-time monitoring unit based on WSN is responsible for acquiring and transmitting the data, which consists of a number of sensor or router nodes and a network coordinator, and is deployed at the site of the brine well mining. Meanwhile, the RMIS serves as the management system for end-users, which has 4 functions: 1) Managing static information of the brine well; 2) Maintaining the database for the data acquired by the WSN; 3) Providing functions to automatically control the speed of brine pump according to real-time operating state data of the brine pump or shut down the brine pump when the monitoring indicators exceed the threshold; 4) And generating a list of mining brine failure reports of mining equipment. The system is evaluated by testing the power consumption of sensor nodes first. The experimental results showed that the package loss ratio (PLR) of the nodes gradually decreased with the increase of the transmission power. However, the battery consumption increased with the increase of the transmission power. The transmission power was configured as 1 dBm which could prolong the lifetime of sensor nodes to 13.5 months. And then the PLR and RSSI (received signal strength indicator) of sensor nodes were tested in different distance and transmitting power, respectively. In the case of the same transmission power, the PLR and RSSI had the opposite change trend with the change of distance: The PLR increased and the RSSI decreased with the increase of the distance. The effective transmission distance of the nodes was 30 m when they were placed on the ground and their PLR was less than 3.6%. Last, the RSSI was also tested within 24 h, to analyze the influence of the field deployment environment on the link quality. The experimental results showed the RSSI was relatively better during the daytime (5:40-19:20) which ranged from ?80 to ?56 dBm. And during the night (00:00-5:40 and 21:30-24:00), the RSSI had a significant drop (around ?85 and ?95 dBm, respectively). And the system test under the potash production environment proves that monitoring data can accurately reflect the operating status of the pump and the brine level.