01 Introduction
Flammulina velutipes, a pure low-temperature mushroom, is one of the earliest cultivated edible fungi in my country. The current cultivation and production has spread to all parts of the country, and it has also become one of the varieties of edible fungi. With the upsurge in the consumption of Flammulina velutipes, the "factory production" of Flammulina velutipes has emerged in the north and south. The only indispensable thing is the low-temperature fruiting room. The cold storage requires refrigeration rooms, low-temperature halls, freezing rooms, and pre-cooling rooms. The temperature control of each unit is different, and each unit needs to operate independently to adjust the temperature and control, and also needs to coordinate networking and monitoring management.
02Analysis of management difficulties
✩ Ventilation: Cold storage is an oxygen-deficient environment. After half an hour of ventilation, the concentration of carbon dioxide will return to a constant value after 0.5 to 1 hour. Therefore, insufficient air volume is a common problem. It is easy to form a mushroom body with a pointed mushroom cap and a slender handle, which is a sign of hypoxia. As long as the mushroom body is in the bag, it is not afraid of ventilation. The air circulation in the warehouse is necessary to improve the state of the mushroom body. The contradiction between ventilation and dehumidification and temperature increase can be solved by reducing commuting or ventilation spray water.
✩ Temperature: The temperature required for the three stages of budding, inhibition and elongation are high, low and medium. Low temperature induction before budding and relatively high humidity in the budding period can accelerate the occurrence of primordia; low temperature in the inhibition period supplemented by strong wind can improve mushroom body quality and increase yield; low temperature in the elongation period can also help increase yield and prolong shelf life. During this stage, the traditional management that does not dare to ventilate should also be changed.
✩ Humidity: Humidity varies with temperature. Low temperature and high humidity, temperature rise and lower humidity can prevent disease occurrence; high humidity is conducive to dense mushroom production, and low temperature and high humidity are conducive to increasing mushroom weight.
03 Control System
Aiming at the above difficulties in automatic control, the automatic cold storage control system adopts Edimensional 200 series PLC and Evian UH series panels to form an open, modular, scalable and cost-effective automatic control solution for cold storage to ensure the safety, reliability and reliability of the refrigeration control system. Efficient, stable, and energy-saving operation, improving the working conditions of workers, and upgrading the manufacturing level of electronic control supporting equipment. The control system is as follows
|
Module model |
Order number |
Number |
|
UN226CPU |
1 |
|
|
EM231 |
1 |
|
|
EM235 |
1 |
|
|
HMI UH507 |
1 |
|
|
Inverter UT500 |
UT533-5RSG1-1XA0 |
1 |
✩UN226CPU has high-speed computing and data processing capabilities, and larger user storage space. Simple and flexible PID sub-functions with unlimited points can facilitate users to realize PID control with more channels. Using FLASH technology for ultra-long power-down retention, without battery support, data can be stored for up to 10 years. Number of communication ports: 2 RS-485 interfaces (both support PPI communication protocol).
✩ The configuration of UH507 series touch screen is simple and convenient, and the communication with UN200 series controllers can be realized with simple settings. Panel products are exquisite in workmanship, convenient in configuration and stable in communication, ensuring the stable operation of the system.
✩Edimensional UT500 series inverter, through the analog input and output of EM235, can adjust the temperature in the cold storage at any time, so that the temperature can be kept around the set temperature, which is constant and does not fluctuate and saves energy.
04 Summarize
The project uses 14 sets of control systems to control the temperature, humidity and ventilation environment of 14 workshops respectively. The use of Yiwei UN200 series programmable controllers can collect in real time the operating conditions of each equipment in the entire cold storage and various process operating parameters, and complete the automatic control of refrigeration and corresponding circulating water systems (automatic start and stop of refrigeration compressors; ammonia pump circuit; cold air Machine control circuit; cooling tower circuit; water pump circuit, etc.), and can reasonably solve and coordinate the optimal cooperation between the various process units in operation. The automatic control system also has advanced self-diagnosis function and discrimination ability, so that the entire cold storage system can be normal Stable, safe, efficient, and low-consumption operation reduces the workload of operation and maintenance, improves economic benefits, and perfectly solves the above-mentioned management problems.
