1、 1 PLC in the Ice Storage Central Air-conditioning System of Control 1 Introduction Ice storage air-conditioning is the Central Valley will be redundant power grid electricity at night to form ice cold storage, electricity consumption peak during the day when the ice will melt to provide air-conditi
2、oning services. As in most parts of Chinas electricity at night is much lower than during the day, using ice cold storage central air conditioning can significantly reduce the users operating costs. Ice storage central air-conditioning system configuration of equipment than conventional air-conditio
3、ning system to increase the number and require a higher degree of automation, but it automatically to meet the requirements of the air-conditioned buildings throughout the day under the conditions of the day will be with all the energy spent, the largest At least to save operating costs. 2 Control s
4、ystem. Control system from the next crew (the scene control workstations) and PC (central management workstations), with the crew using programmable logic controller (PLC) and touch screen, PC using industrial-grade computers and printers, system configuration necessary if the annex Communications e
5、quipment interface cards, modems, etc., to achieve the parameters of the storage system and automatic intelligent run. The crew at the scene and touch-screen system can control parameter settings and data. PC remote management and printing, which includes the crew and all the features touch screen.
6、Following the system as a whole crew of the industrial PLC as the core, the automated control. Control equipment and devices include: detection sensor components, electrical valves, converter, and so on. 2 2.1 Under the machine system (Regional workstations) 2.1.1 TP21 touch-screen TP27 used as a co
7、lor touch-screen operation panel, completely replace the conventional switch button, light, and other devices to control more interviews counters clean. And, TP27 touch screen can be realized at the scene state, system settings, the model chosen, the set of parameters, fault recording, load records,
8、 time period, real-time data, load curve and reporting statistics, and other functions, the Chinese user interface intuitive and friendly. 2.1.2 SIEMENS PLC SIMATIC S7-300 series PLC applied to all walks of life and various occasions in the detection, monitoring and control of automation, its power
9、to both the independent operation of, or connected to a network able to achieve complex control. The photoelectric products with isolation, high electromagnetic compatibility； have high industrial applicability, allowing the ambient temperature of 60 ； has strong anti-jamming and anti-vibration and
10、impact resistance, so in a harsh working environment has been widely Applications. I also mean freedom of communication S7-300 type PLC s a very unique feature, which allows S7-300-PLC can deal openly with any other communications equipment, communications controller, or PLC S7-300 type can be defin
11、ed by the users own Communications protocol (of the agreement ASCII), the baud rate to 1.5 Mbit / s (adjustable). So that can greatly increase the scope of communications so that the control system configuration more flexible and convenient. Of any kind with a serial interface peripherals, such as:
12、printers or bar code readers, Drives, a modem (Modem), the top PC-connected, and so can be used. Users can program to develop communication protocols, the exchange of data (for example: ASCII character code), RS232 interfaces with the equipment can also be used PC / PPI cable linking the free communication communications.
