Project Introduction
Industrial water chillers are used in a variety of applications where chilled water or liquid is circulated through process equipment. Water chillers are commonly used to cool products and machinery in a multitude of different applications including injection molding, tool and die cutting, food and beverage, chemicals, lasers, machine tool, semi-conductors and more.
The function of an industrial chiller is to move heat from one location (usually process equipment or product) to another place (usually the air outside the manufacturing facility). It is very common to use water or a water/glycol solution to transfer the heat to and from the chiller which may require the process chiller to have a reservoir and pumping system. Regardless of related industry and process, make sure that having sufficient cooling is critical to productivity and cost savings.
Features
· We use PLC in place of dedicated controller and monopoly of controller is reduced.
· Auto Correction of pressure and temperature ratio with 2 stepper motors as 2 compressors are used. This function is not available in dedicated controller.
· Cost effective as PLC is used.
· Reduced the complicated wiring.
· Easy to use and operate, HMI is adopted in every application.
Solution
PLC Commissioning:
1. Connect the wires according to the wiring diagram of the system. Before commissioning, disconnect all power of the panel. Then ensure that the wiring is correct and the ground wires are in good connection (including the grounding of the panel).
2. Check all the input & output wiring of PLC. Details of IO is given below:
3. There are 2 compressors logics in PLC. There are some temperature and pressure feedbacks in the compressors as you can see in the pictures.
4. Process control, press the cycle start button first, which means compressor is ready to start, then compressor-1 button is pressed and it will check the condition that emergency button is not pressed, and then it will start the compressor that runs less time first, after that it will check the condition that the requirement of set temperature is achieved or not. If achieve, then it will run with single compressor. If not, then it will start the 2nd compressor. Then it will check the current temperature with set temperature accordingly it will stop the compressor.
5. There is a main function of auto maintain the ratio of temperature and pressure. Here we used 2 stepper motor to maintain the same. We start the stepper motor as per the requirement. This function is not available in the dedicated controller
Advantages
Low cost
High efficiency
Advanced features like pressure and temperature ratio adjustment
200 Alarms display
Application figures
Summary
In most process cooling applications, a pumping system circulates cool water or a water/glycol solution from the chiller to the process. This cool fluid removes heat from the process and the warm fluid returns to the chiller. The process water is the means by which heat transfers from the process to the chiller.
Process chillers contain a chemical compound called a refrigerant. There are many types of refrigerant and applications depending on the temperatures required but they all work on the basic principle of compression and phase-change of the refrigerant from a liquid to a gas and back to a liquid. This process of heating and cooling the refrigerant and changing it from a gas to a liquid and back again is the refrigeration cycle.