Research On Variable Frequency Regulating Speed And Protection System Of Central Air-condition

As everyone knows, the energy is basic resources of national economic development. Asevery profession and trade of our country are being developed constantly, the energy questionis outstanding day by day in our country, and unable to solve at all in the near future, theenergy conservation is quite arduous. In such environments as the enterprise, office block,commercial building, hotel of modem factory, etc., the central air conditioner system isindispensable, though it can provide a comfortable environment for people, but the powerconsumption is quite large. So, paying attention to environmental protection andenergy-conserving today day by day people, energy-conserving problem this of the central airconditioner is a key technology problem that people expect to solve.Central air conditioner system air blower besides dissipation energy of the hostcomputer, freeze, cool water pump whether the second largest consume energy equipment,because air blower, freeze disposition of coolant pump large flow (sets the Day amount freeon this basis)summer to come to the certain, and because of the climate situation while usingactually, such changes of different factors as objective flow activity content, etc., constantchange of necessary load (load seldom reaches the maximum). So in order to make thesystematic temperature of central air conditioner steady, need the air blower according to theoperating mode change, freeze, the coolant pump is regulated, this needs betterautomatically controlled module. Now, with electric and electronic technology, developmentof micro electric technique, use frequency conversion transfer speed technology and PLCautomatic control system can economize the electric energy and raise the automatic degree ofthe system by a large margin Now, along with the technical development of electric powerelectronics technique, micro-electronics, the application of the technique of the variablefrequency and PLC automatically control system can save electricity energy with significanteconomy electric power and the exaltation system of automation and make the system have alot of advantages ,for example the credibility, structure of movement to simplify, support tomaintain convenient. So it can be used for lately central air condition of set up the guest house mansion in also can used for to a great deal of technique reformation of old type centralair condition, have the extensively applied realm.This text has explained some basic thinkings and methods that the systematicautomation of the central air conditioner is controlled and energy-conservation is designedbriefly, have recommended exchanging the frequency conversion of the motor and adjustingthe characteristic of the speed and energy-conserving principle, having also recommendedSiemens S7-200 main function to touch the lump and function, PID algorithm adjusts theapplication in the constant voltage water -supply system of the speed in frequency conversion,and has made a detailed instruction to main return circuit and hardware part of controlling thereturn Circuit of the system. This subject is mainly to export temperature to measure to the airconditioner, adopt the frequency converter to regulate the rotational speed of the central airconditioner, make it run high-efficiently, achieve the energy-conserving goal.