The cold storage has gone through the original mechanical refrigeration, ammonia liquid equipment refrigeration, and fluorine equipment refrigeration to the current environmentally friendly and energy-saving cold storage, step by step toward today's more energy-saving, environmentally friendly, and more effective automated management.

1. The main features and problems of the cold storage energy-saving control system
(1) The automatic control level of cold storage equipment is low and completely relies on manual operation. However, people's subjective initiative and technical level are very different due to human factors and time, and it is difficult to achieve control.
(2) Compressor star-triangular start will impact the compressor equipment and the power grid, affecting the service life of the equipment; moreover, the equipment can only run at full speed after the start is completed, and the refrigeration capacity can be controlled by adjusting the opening degree of the return air valve (evaporation pressure) . This results in waste of power consumption, high equipment failure rate, and poor operating economy.
(3) According to different storage or storage conditions and differences in thermal insulation performance, it is difficult for each branch library to automatically adjust the cooling capacity according to its own needs, causing excessive cooling waste to the branch library that does not need cooling. ; Evaporator defrosting and cooling water pump operation are difficult to achieve results.

2. Purpose of automatic control transformation With the development of electronic technology, the mature development of programmable logic controller (PLC), AC frequency conversion speed regulation technology, and the large number of applications of various types of detection sensor transmitters, automatic control The functions are getting stronger and stronger, and the system optimization and energy-saving management and control capabilities are getting stronger. It provides a good precondition for the automatic transformation of cold storage.
The purpose of the transformation is to realize automatic intelligent control through the transformation, improve the quality of cold storage storage, reduce power consumption, increase the service life of the equipment, reduce the failure rate of the equipment, and reduce the cost of the staff on duty. Comprehensively improve the efficiency of cold storage and ensure the recovery of investment costs within 2 years.

Three, the main work of equipment transformation
(1) The automatic control system of the cold storage adopts S7 PLC control and programming; the data communication with the host computer is realized through MPI communication; for the large-scale cold storage, the Profibus-dp communication method is adopted to realize full data with the control equipment of each branch cold storage and cooling room comminicate;
(2) The refrigeration compressor is driven by an AC variable frequency speed regulating device; it realizes full data exchange and control through modbus communication and PLC;
(3) Use the host computer + industrial touch display (or touch screen) + wincc configuration software to make the host computer management screen of the cold storage system. Real-time dynamic display of the operating status of all equipment in the cold storage, recording equipment operating parameters and operating curves, providing energy-saving data analysis data, and real-time alarming of various abnormal phenomena.
(4) The intake valve of the regulating station is changed to an electric mechanism, and various required sensors are added to realize PLC automatic control.
(5) Realize the automatic operation and debugging of the refrigeration system of aquatic cold storage.

Fourth, the functions that the equipment has after transformation:
(1) The upper computer management and control of the entire cold storage system. On the upper computer, the temperature of each cooling room in the cold storage, the operating status of the compressor, and the working status of each point of the equipment are displayed on the upper computer in real time, such as equipment start and stop, operation, failure, and valve control. Status, set temperature value and actual control value of each cold room, etc., record the temperature of each cold room with a curve, and the operating load current of the compressor. Real-time monitoring and alarming of parameters such as temperature and pressure, display of parameters such as return valve pressure and operation of operating equipment. It has the process temperature for storing different storages in different refrigeration rooms, and sets the process parameter database such as storage temperature and refrigeration capacity (return air pressure) for users to call.