how chillers work
To understand what kind of chiller you need, it is best to understand how a chiller works in the first place. Understanding the fundamentals of chillers can give you a better idea on why the chiller is important, how to maintain it, and what to fix by the off chance something goes wrong. As you can see from the image, this is a basic refrigeration system that is used in most refrigeration systems these days. It has an evaporator, a compressor, a condenser and a metering device. Refrigerant is cycled through the system and goes through various temperature and pressure changes, resulting in it changing phases. Our industrial chillers use this cooling effect to chill water, glycol or just about anything.
Through careful calculations, Drake engineers create the files to accurately punch (cut) the sheetmetal to suit each chiller. This sheetmetal is usually galvanized steel, but a few systems require stainless steel for a more polished look. Afterwards, we seperate the pieces from the main body, debur them and send it off to bending.
After the metal is punched and deburred it is time to bend them. Some of the sheetmetal needs to be formed into a certain shape to establish a firm connection as a skeleton of the chiller. Bending takes a lot of precision and accuracy. If the metal is not bent at the proper angle, the entire beam may not fit correctly into the chiller assembly.
Now we put everything in its place. With the punched sheets and bent metal, we form the frames of the chiller and lock them together with sheetmetal rivets and nuts & bolts. We assemble the required parts that can bring the chiller to life. The metal has holes in the proper location for the selected components to ensure no drilling is required for this step. In the most fundamental basics, a chiller must have a compressor, evaporator, condenser and expansion valve. Specialized chillers might require different variations of these basic components.
We have all the parts assembled and locked in, but we need to connect them all. That is where the copper tubes come into action. Copper tubes are the veins of the chiller, it connects all of the vital parts of the chiller and makes the unit work in a cycle and function as one. The reason why copper is the go-to material for pipes is because of its flexibility, durability and ease of installation. This process is time consuming, and requires a great deal of experience to figure out the best path for the pipes. Most units have pre-programmed pipe bends for use with both of our CNC Pipe Benders. This eliminates most of the braze joints from the chiller resulting is a more robust and reliable chiller.
With the copper tubes fitted, the next step would be securing that connection by announcing their marriage in holy matrimony, so they can be together forever. That is where brazing comes in. Brazing is a metal-joining process by using a highly concentrated flame to heat up a filler metal between the joints of the pipes. The filler metal has a lower melting point than the pipes, thus when the filler metals melt, it is able to flow inside the gap between the pipes by capillary acition. Afterwards, the filler metal cools down and solidifies itself to the copper, creating a firm connection.
Wiring is initially a separate process from the loading, piping and brazing. The panels are wired simultaneously with these processes. Wiring the panel can be fairly complex and requires precise measurement. The idea is to fit all the wires, interfaces, processors, microchips, and adapters into a metal box. Ultimately the panel ties in with the chiller prior to testing. This is where the panel is then fitted up to the unit and all major components are wired back to the panel.
Finally, we test it. This makes startup in the field very simple. We power the units, adjust all appropriate setpoints and run the unit to ensure proper operation. The condensing pressure, suction pressure and superheats are dialed-in to ensure very minimal field work on startup.
After testing, the chiller is ready for the customer. We carefully package each product to insure the safety of each chiller. Thus, when the chiller arrives to the designated location, the chiller is in the solid condition for cooling your process.