Welcome to Paul from engireeringMindset.com, in this video We will look at the basics of the operation of the central chilled water system It is a typical system for office buildings around the world We have a model of a basic office building just out of all the interior stuff imagine In fact, the roles will be filled with humans, computers and central server rooms It will generate a lot of heat, especially when the building is exposed to the sun in the middle of summer So this building must produce a lot of cooling to deal with this heat to maintain an ideal temperature So how is this done first we need equipment for example here there is a water cooling unit With distribution pumps And air handling unit and cooling tower on the ceiling If a water cooling unit produces cold water in this system The water cooling unit has two main cylinders.The first is the evaporator In which chilled water is produced The other cylinder at the rear is the condenser The heat from the building is collected and sent to the cooling tower In fact this is the stillness of the water cooler Here we have an evaporator which is insulated to keep cool inside Here the compressor, power source and control unit are shown. This is a centrifugal water chiller because there are many different types Which we will not go into in detail in this video We just want to understand the basics of how to cool this building If the chilled water comes out of the evaporator The pump is pulled by the pump and can also be pushed in. Here you notice the pipe covered in dark blue is coming out of the evaporator and placed dark blue to know that it is a very low temperature, the degree of exit is about 8 degrees Celsius, or 6 to 8 degrees Celsius It leaves in this design at 54 liters per second The other pipe with a light blue color to know that it is at a higher temperature of about 14 degrees Celsius or 12 to 14 possible slightly higher or lower depends on the system design and convection of the building Actually the pipes will not be colored this color They can be this color but this is unlikely, their shape in the real world will look like this as you can see here CHW chilled water Flow and chilled water returned We have a colored sticker and illustrative arrows and almost all of the equipment rooms will find a pipe with similar stickers But for illustrative purposes Cover them here so you can understand how the system works If the pump pulls the cooled water at about 8 C and sends it to an upward pipe The shape of the real pump is similar to this and is a direct coupled centrifugal pump The engine at the rear here is connected to the pump but unfortunately it is under isolation you can not see in this picture The chilled water is sent upward in the upstream pipe in this pipe With the height of the building And branch out from the ascending tube to feed the air handling unit The shape of the air handling unit in real life is similar to this.This is an example of a small unit. Here we have the flow back from the cooling or heating coil and I will explain it in moments And here we have a file for heating and another for cooling I’ll talk about them next If the task of an air handling unit is to take warm air from the office Pull it through a fan and pump it to the other side To distribute it through the ducts to different points that you need inside the office In the air handling unit there is a thermal coil and in fact its shape resembles this The chilled water enters the coil and looks through these little rings here And graduated from the top here Enter at 8 C in this example and when you reach the top you will leave the coil at 14 C If this rise in heat because of the air that passes in the unit handling air to cool If warm air enters and passes on the coil, the coil moves its coolness to the air and the air conveys its heat to the coil Air leaves at a lower temperature and water leaves at a higher temperature The air handling unit can be one in one or more or it can be one here and the air duct connects to a number of roles and this is only for illustrative purposes to help you understand This “check” water cooler returns to the rising pipe to feed the evaporator of the water cooling unit in the bottom Inside the water cooler is a separate system that rotates between the condenser and the evaporator and also the steering blades below This is a cooling cycle that occurs inside.What happens here is that the heat inside this pipe is removed by the cooling fluid And sent to the condenser to get rid of its heat to go to the cooling tower. Inside the “water cooler” looks like this, we have one hand “evaporator” which is the coldest side “Intensive” destination here And also “compressor” with “steering blades” at the bottom If the “cooling fluid” flows inside the system here, it conveys heat from one side to the other in continuous flux We have other videos on the cooling cycle if you want to learn more check them out So the heat inside this pipe here was transferred to the “condenser” side. The “condenser” sends this water – now called condenser water – to the cooling tower Here I covered this pipe in red to know that the temperature is higher In this example about 35 degrees Celsius Its flow rate is about 58 liters per second in the direction of the “cooling tower” above This can be changed This represents this design only for illustrative purposes And here we have the return water of the condenser in this example about 28 degrees so when going to the cooling tower and its return lost 7 degrees here in this design but in the real world can not be so high In winter, the difference will be much lower Yes, in the real world, the condenser pipe is like this I apologize, not this, this pipe “see” the water cooled disperse that he will write here condenser water and some of the signs and other colors I apologize for using the wrong image If warm condenser water is sent to the cooling tower on the roof of the building In this example it is an open cooling tower which means that the condenser warm water enters the cooling tower as a spray This spray drops down into the cooling tower and is collected at the bottom The air flowing in the opposite direction flows through these fans here These fans pull the surrounding air out of the building into the cooling tower and pull it out from above In this process warm condenser water will lose some of its heat and the air entering and leaving the cooling tower will come out at a much higher temperature than it entered It will also carry some humidity if its relative humidity will also rise A real cooling tower that looks like this from Baltimore Aircoil.This is a typical cooling tower that can be found on the roof of many buildings. And just to give you an idea if you’re not familiar with the cooling towers, This is New York City and you can see approximate all buildings have cooling towers of a certain size or another and some have more than others this depends on the size of the building and indoor activity They are on the roof of any large building, in almost every city around the world So when the cooling tower water is lost about 7 degrees in the cooling process it is collected at the bottom and then sent down Into the condenser pump and pump into the condenser In fact I have put this pump wrong here Obviously the exit should be the other side but this free video if @ #% ^ $ 🙂 So here is where the condensate water returns to these coils inside here to carry more heat and is sent back to the cooling tower It is important to know that the condensed water system and the cryogenic water system are completely separate and inactive It does not exchange water between them, but is the cooled fluid is what works in the cooling cycle Among these units it is the only thing that moves between them The water here is sealed inside the pipes and leaves for these pipes Also in this example we have one stomach, one mechanical In fact, it is unlikely that you have one equipment, probably n + 1 So n is the number you need plus one Because if this pump is broken, this pump is broken.We cannot generate cold water or condensed water. So at least we will have two units, one working and one on standby, if only one equipment is working They will take turns on the service, the first pump will work for a week and then the other will work for a week and so on This also allows you to perform the necessary maintenance of the system In large buildings you will have a much more complex system. You can have two, three, four or more water coolers. More air handling units and more or larger cooling towers The complexity of the system depends on the convection of the building You may even have a number of separate chilled water systems that you can have for critical places For example, a system supplies server rooms just because they need cooling around the clock You will also have these common central systems that deal with the heat of the place in the roles This is a very initial look and we will go into more complex systems in the next videos Thanks for watching and I hope you watch other videos .