Hi, Paul this is Abdul ahad from Pakistan . I am working on a Johnson control Yz centrifugal chiller. Watching your videos and I want to say that you have done an excellent work. Thanks alot. Help me clear the concept please. When Vane guide control the flow of refrigerant by throwing a refrigerant to an angle it decrease the kinetic energy, so does it also means the refrigerant entering to condenser though discharge line has low temp due to this?
Many thanks for sharing your knowledge with us. In here your talking about centrifugal compressor , so in screw type compressor what is the capacity control method?
Thanks for the video...I REALLY DO APPRECIATE IT.. am still waiting for the next another video form this chanel...I HOPE it would be all about the wiring diagram which is controlling the system in its sequences,thank you so much.
IGVs impart a pressure drop in the refrigerant loop lowering its density. The compressor is a volumetric device so now each unit volume of refrigerant has less mass. The evaporator is a mass device so there is less mass flow from the restricted inlet thus less capacity. The IGVs also pre-swirl the refrigerant thus keeping the compressor on its curve. The compressor generates constant compression ratio at constant speed so the outlet pressure is proportionally lower due to lower inlet pressure. Capacity has nothing to do with refrigerant angle of incidence but stability does. A simple butterfly valve could be used but they impart too much turbulence at low opening and don’t give the range of IGVs because of their flow characteristics.
Usually they will work independent. If due to more cooling demand the motor and impeler are spinning faster, or vanes are opened by control system, the expansion valve (be it hydraulic or electric) will open or close to maintain the proper suction line temperature, so it will follow indirectly the control, but usually will not be operated directly. Some more advanced systems will operate electronic expansions valves in tandem, and also be able to diagnose issues, if their position is not what is expected.
Hey Devid, the motor rotates the impeller in the compressor, this moves the refrigerant around the system. We will do a video soon on the motor, but for now you can see inside a motor and the compressor in this video th-cam.com/video/PT0UIqAGacg/w-d-xo.html
What happens if the day is cold, from the controller can I raise the cold generation range, other than 6 ° C but 12 ° C? This directly affects the flow of refrigerant that will allow the passage to the expansion valve by means of the thermal valve that is in the suction line towards the compressor, is it correct? How can I calculate how much coolant is required to cool a degree of temperature.
It actually founded useful even but I know the 3D dimension of the compressor to draw, labels and creativity because it's founded difficult to understand about the name of the labels and demonstrations for my work experiences.
Isn't this very similar to an expansion valve ? Would this drop the pressure as well? Even though the vapor should already be at a low pressure coming from the evap? Why can't we use an expansion valve for capacity control?
motors are rated for a certain amount of current, if they exceed this they will become too hot and melt their insulation so they are rated and usually have a thermal cut out which cuts power if it reaches too hot or too much current flow
Hey thanks for this great videos. Question aren this temperature sensors usually located in a well or they need to be in direct contact with the water, refrigerant or oil?
Hey Jaylenne. Refrigerant sensors tend to sit on the pipe wall externally with insulation around them, water sensors will sit inside the pipe in a well but you will come across externally mounted ones.
Guide vane opening depands on which factor.... Mean our load... Suppose our chilled water is ²5 degree celsius but guide vane is opening Only 20% how we increase it.... By making other parameters i favour of it
RLA is the rated load amps, the maximum your chiller should pull. The run load amps should be less than this and will vary with the cooling load of the chiller.
Rated load amps is the amount of current measured when device is running,Full load amps is Max that the device can pull, if amps pass that mark and no adjustment can be made, then device needs to be tested to insure it will continue to produce design performance.
I thought the cooling capacity was controlled by the expansion valve, as you explained in a previous video. Does it a work in a combination of the expansion valve and the compressor?
I think you should have mentioned that the hot gas leaves first of all the compressor heads up to the cooling tower (your red color line at 32c) cools down them come back as subcooled into the evaporator then leaves the evaporator heading to the AHU ....
This type of chiller doesn't send refrigerant to the cooling tower or AHU. The refrigerant always stays in the chiller, only the condenser water goes to the cooling tower, and only the chilled water goes to the AHU's. The condenser water is completely separate from the chilled water. Only the refrigerant moves around the inside of the chiller between the two circuits.
The Engineering Mindset ok. So that means the refrigerant ( head pressure) from the compressor goes into the Condenser then from the Condenser it condenses to finally send the liquid to the cooling tower then comes back at at lower temp. into the Condenser. From now it'll leave the Condenser once again to go into the evaporator then the evaporator will send out chilled water to the AHU . Am I right .loll
Almost but not quite. So the refrigerant gas condenses into a liquid in the "condenser" of the chiller, it then moves to the expansion valve and then into the evaporator before getting sucked back into the compressor and pushed into the condenser again to repeat the process. The refrigerant (gas or liquid) remains completely separated from the water which flows in the condenser water loop or the chilled water loop. Have a watch of the other videos on chillers before moving onto these more advanced ones. Make notes and sketches along the way to help you understand it. Chiller basics part 1 - th-cam.com/video/0rzQhSXVq60/w-d-xo.html Chiller basics part 2 - th-cam.com/video/3ZpE3vCjNqM/w-d-xo.html Compressor - th-cam.com/video/PT0UIqAGacg/w-d-xo.html Evaporator - th-cam.com/video/W3w7FpX9j9k/w-d-xo.html
the video should not be describing chill and condensor water layout. instead it should combine vane guide and hot gas bypass. also show compressor surge graph and when hot gas bypass is required.
⚠️ *Found this video super useful?* Buy Paul a coffee to say thanks: ☕
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Very professional video, thank you for sharing
Great job on this video! really needed this to understand more!
thanks a lot. finally I understood what capacity modulation is. very informative thanks.
Thank you for your outstanding explanation it was useful indeed I'm making service to one of this type of chillers
outstanding, very easy to understand, thanks
A very informative and detailed video. Thank you for sharing. Can you recommend a textbook for chiller maintenance and repairing?
Bigger thinks for your VDO...!
Great job! thank you for the lesson.
Thank you for this video, clear and informative.
Thanks for sharing this video very helpful
Thank you
Great videos man, thanks
amazing, you explain everything so good. thanks
Many thanks to you mate, that was great..
Hi, Paul this is Abdul ahad from Pakistan . I am working on a Johnson control Yz centrifugal chiller. Watching your videos and I want to say that you have done an excellent work. Thanks alot. Help me clear the concept please.
When Vane guide control the flow of refrigerant by throwing a refrigerant to an angle it decrease the kinetic energy, so does it also means the refrigerant entering to condenser though discharge line has low temp due to this?
Very knowledgeable
Sir plz share one clip about high compressor lift alarm in centrifugal compression system.
Many thanks for sharing your knowledge with us. In here your talking about centrifugal compressor , so in screw type compressor what is the capacity control method?
Thanks for the video...I REALLY DO APPRECIATE IT.. am still waiting for the next another video form this chanel...I HOPE it would be all about the wiring diagram which is controlling the system in its sequences,thank you so much.
Hi Dimas, it;s coming soon don't worry. Glad to hear you enjoy the videos and they are helping you.
Very well explained! Your videos are very good quality. Keep the good work going.
Really love the content ❤. I’m wondering what qualifications do you need to become a chiller tech
i see , thank for the info, so vsd similar to inverter, vane guard to vrf
VFD Video is now live! here: th-cam.com/video/yEPe7RDtkgo/w-d-xo.html
New VRF unit video here:➡️ th-cam.com/video/4i1XgcP1tmw/w-d-xo.html
IGVs impart a pressure drop in the refrigerant loop lowering its density. The compressor is a volumetric device so now each unit volume of refrigerant has less mass. The evaporator is a mass device so there is less mass flow from the restricted inlet thus less capacity. The IGVs also pre-swirl the refrigerant thus keeping the compressor on its curve. The compressor generates constant compression ratio at constant speed so the outlet pressure is proportionally lower due to lower inlet pressure. Capacity has nothing to do with refrigerant angle of incidence but stability does. A simple butterfly valve could be used but they impart too much turbulence at low opening and don’t give the range of IGVs because of their flow characteristics.
I see at the end of the video, you've used kind of chiller simulation program, may I know the name or link of this program please?
Pls explain capacity control of screw chillers
How about VSD centrifugal compressor? In that case do they also have guide vane? And which is a priority to control? VSD speed or vane opening?
Please watch our turbocor chiller video
How does the vane control work in tandem with the expansion valve? The expansion valve can also be allowed to open only as much as required, right?
Usually they will work independent. If due to more cooling demand the motor and impeler are spinning faster, or vanes are opened by control system, the expansion valve (be it hydraulic or electric) will open or close to maintain the proper suction line temperature, so it will follow indirectly the control, but usually will not be operated directly. Some more advanced systems will operate electronic expansions valves in tandem, and also be able to diagnose issues, if their position is not what is expected.
Thankc for the support....could you please tell me what is the use of induction Moter installed with the compressor unit????
Hey Devid, the motor rotates the impeller in the compressor, this moves the refrigerant around the system. We will do a video soon on the motor, but for now you can see inside a motor and the compressor in this video th-cam.com/video/PT0UIqAGacg/w-d-xo.html
Thanks a great
Just curious as to why the induction motor housing would be insulated. Wouldn’t you want to bleed off as much heat from that motor as possible? Thanks
Guide vane or Inlet guide vane
on what parameter does the guide vanes operate? evaporator refrigerant pressure or leaving chilled water temperature?
Typically it will operate from the water temperature
Keep going please
What happens if the day is cold, from the controller can I raise the cold generation range, other than 6 ° C but 12 ° C? This directly affects the flow of refrigerant that will allow the passage to the expansion valve by means of the thermal valve that is in the suction line towards the compressor, is it correct? How can I calculate how much coolant is required to cool a degree of temperature.
Great ❤️❤️❤️
It actually founded useful even but I know the 3D dimension of the compressor to draw, labels and creativity because it's founded difficult to understand about the name of the labels and demonstrations for my work experiences.
My screw chiller 100 ton but cooling load only 35 ton can i unload screw chiller to 50% and reduce flow rate of chilled and condenser water
Isn't this very similar to an expansion valve ? Would this drop the pressure as well? Even though the vapor should already be at a low pressure coming from the evap? Why can't we use an expansion valve for capacity control?
What compresser efficiency
what do you meant by max A of motor to protect it ?
motors are rated for a certain amount of current, if they exceed this they will become too hot and melt their insulation so they are rated and usually have a thermal cut out which cuts power if it reaches too hot or too much current flow
Hey thanks for this great videos. Question aren this temperature sensors usually located in a well or they need to be in direct contact with the water, refrigerant or oil?
Hey Jaylenne. Refrigerant sensors tend to sit on the pipe wall externally with insulation around them, water sensors will sit inside the pipe in a well but you will come across externally mounted ones.
How to do this about the experiment?
Guide vane opening depands on which factor.... Mean our load... Suppose our chilled water is ²5 degree celsius but guide vane is opening Only 20% how we increase it.... By making other parameters i favour of it
superrrr
could you tell me what information I am I supposed to understand from the rated load apms?
RLA is the rated load amps, the maximum your chiller should pull. The run load amps should be less than this and will vary with the cooling load of the chiller.
Rated load amps is the amount of current measured when device is running,Full load amps is Max that the device can pull, if amps pass that mark and no adjustment can be made, then device needs to be tested to insure it will continue to produce design performance.
thanks
I thought the cooling capacity was controlled by the expansion valve, as you explained in a previous video. Does it a work in a combination of the expansion valve and the compressor?
For centrifugal chillers yes. You might like this new video on expansion valves th-cam.com/video/oSLOHCOw3yg/w-d-xo.html
I think you should have mentioned that the hot gas leaves first of all the compressor heads up to the cooling tower (your red color line at 32c) cools down them come back as subcooled into the evaporator then leaves the evaporator heading to the AHU ....
This type of chiller doesn't send refrigerant to the cooling tower or AHU. The refrigerant always stays in the chiller, only the condenser water goes to the cooling tower, and only the chilled water goes to the AHU's. The condenser water is completely separate from the chilled water. Only the refrigerant moves around the inside of the chiller between the two circuits.
The Engineering Mindset ok. So that means the refrigerant ( head pressure) from the compressor goes into the Condenser then from the Condenser it condenses to finally send the liquid to the cooling tower then comes back at at lower temp. into the Condenser. From now it'll leave the Condenser once again to go into the evaporator then the evaporator will send out chilled water to the AHU . Am I right .loll
Almost but not quite. So the refrigerant gas condenses into a liquid in the "condenser" of the chiller, it then moves to the expansion valve and then into the evaporator before getting sucked back into the compressor and pushed into the condenser again to repeat the process. The refrigerant (gas or liquid) remains completely separated from the water which flows in the condenser water loop or the chilled water loop.
Have a watch of the other videos on chillers before moving onto these more advanced ones. Make notes and sketches along the way to help you understand it.
Chiller basics part 1 - th-cam.com/video/0rzQhSXVq60/w-d-xo.html
Chiller basics part 2 - th-cam.com/video/3ZpE3vCjNqM/w-d-xo.html
Compressor - th-cam.com/video/PT0UIqAGacg/w-d-xo.html
Evaporator - th-cam.com/video/W3w7FpX9j9k/w-d-xo.html
The Engineering Mindset thank you. Am gonna watch them. It seems like I was getting confused between the chillers system and the refrigeration system
the video should not be describing chill and condensor water layout. instead it should combine vane guide and hot gas bypass. also show compressor surge graph and when hot gas bypass is required.