Chiller - Expansion Valve HVAC
video description
Date: 2023-11-17
Related videos
Comments and reviews: 29
Sh1
Hello sir,
I would like to tell you that the first chiller has a float or orifice plate and the small tx valve is used for motor/vfd cooling as the base of the orifice chamber has liquid in it. As this style evaporator is flooded superheat is definitely not used for refrigerant control as it is likely to only be 1k. We work on approach with flooded type evaporators.
The 3rd chiller is a Trane RTHB it uses a exv than that feeds the economiser, this exv is positioned determined on discharge superheat, the liquid refrigerant in the economiser is then controlled into the evaporator through a orifice plate, the sub cooled vapour in the economiser is scavenged and recompressed. This style evaporator is also flooded. The later trane RTHC and D also had similar refrigerant cycles but the exv was positioned via a low side float and I believe they may be falling film type flooded evaporators.
reply
Hello sir,
I would like to tell you that the first chiller has a float or orifice plate and the small tx valve is used for motor/vfd cooling as the base of the orifice chamber has liquid in it. As this style evaporator is flooded superheat is definitely not used for refrigerant control as it is likely to only be 1k. We work on approach with flooded type evaporators.
The 3rd chiller is a Trane RTHB it uses a exv than that feeds the economiser, this exv is positioned determined on discharge superheat, the liquid refrigerant in the economiser is then controlled into the evaporator through a orifice plate, the sub cooled vapour in the economiser is scavenged and recompressed. This style evaporator is also flooded. The later trane RTHC and D also had similar refrigerant cycles but the exv was positioned via a low side float and I believe they may be falling film type flooded evaporators.
reply
Mike
Nice video but you don't go into the aspect of the TXV sensing superheat. You mentioned the Thermal Expansion valve shown had an external pressure 'equalizing' line, but didn't go any further. By sensing both the compressor suction PRESSURE and TEMPERATURE, the TXV can actually sense the degree of superheat above saturation. The spring setting can determine the degree of superheat. So a drop in suction pressure will tend to open the valve, even if the suction temperature remains steady and vice versa.
If the valve only responds to suction TEMPERATURE, then an overcharged system can still pass liquid into the compressor under the wrong conditions.
reply
Nice video but you don't go into the aspect of the TXV sensing superheat. You mentioned the Thermal Expansion valve shown had an external pressure 'equalizing' line, but didn't go any further. By sensing both the compressor suction PRESSURE and TEMPERATURE, the TXV can actually sense the degree of superheat above saturation. The spring setting can determine the degree of superheat. So a drop in suction pressure will tend to open the valve, even if the suction temperature remains steady and vice versa.
If the valve only responds to suction TEMPERATURE, then an overcharged system can still pass liquid into the compressor under the wrong conditions.
reply
Sameer
We are experiencing a problem in our chiller system which is having an electronic controllled expansion valve. We have charged the system with 20 kg of R407 gas after having an alarm of low pressure. But it was not rectified and pumping down the system. we could barely see any gas coming back to condenser which was showing 75% when we charged it earlier. What all we have checked is
1. Dryer. ok
2. Evaporater. ok no leakage
3. Expansion valve changed from a already working chiller system.
Please guide us on what could be the possible cause of the syatem showing low pressure.
reply
We are experiencing a problem in our chiller system which is having an electronic controllled expansion valve. We have charged the system with 20 kg of R407 gas after having an alarm of low pressure. But it was not rectified and pumping down the system. we could barely see any gas coming back to condenser which was showing 75% when we charged it earlier. What all we have checked is
1. Dryer. ok
2. Evaporater. ok no leakage
3. Expansion valve changed from a already working chiller system.
Please guide us on what could be the possible cause of the syatem showing low pressure.
reply
Uncle
These videos are really good! Thank you for educating the masses! The mcquay machine your displaying the bulb from the pilot valve goes to a well on the top center evap. There is a temp sensor that is mounted on the suction 90 that gives the suction temp. to the microtech controller. The pilot valve is controlled from that bulb that is mounted in the evaporator. But all in all your videos are fantastic for getting guys familiar with chillers and also us seasoned guys for a little refreshing. Especially when all Ive been doing is rebuilds.
reply
These videos are really good! Thank you for educating the masses! The mcquay machine your displaying the bulb from the pilot valve goes to a well on the top center evap. There is a temp sensor that is mounted on the suction 90 that gives the suction temp. to the microtech controller. The pilot valve is controlled from that bulb that is mounted in the evaporator. But all in all your videos are fantastic for getting guys familiar with chillers and also us seasoned guys for a little refreshing. Especially when all Ive been doing is rebuilds.
reply
Akshay
hey mate, I've been watching these videos actively since starting in building services this year and just wanted to say how well you've explained the content so thanks very much. Some suggestions for potential topics that could be covered for future videos: Absorption chillers, co-gen/tri-gen systems, HVAC technical drawings, maybe even one on how the building services industry works ie. contractors, sub-contractors, consultants, service technicians. Thanks again!
reply
hey mate, I've been watching these videos actively since starting in building services this year and just wanted to say how well you've explained the content so thanks very much. Some suggestions for potential topics that could be covered for future videos: Absorption chillers, co-gen/tri-gen systems, HVAC technical drawings, maybe even one on how the building services industry works ie. contractors, sub-contractors, consultants, service technicians. Thanks again!
reply
Devender
Hello, sir.
Please make a vedio on.
Scaling of condensor evaporator in chillers,
Also best method and tools require for maintenance of water cooled chillers.
Thanks for ur all vedio,
Ur vedio so help full for me and others.
Sir we don't have much money to get tools
Sir, superheat in chiller, I can't understand
How to implement superheat data on small Ac for solving cooling problems.
Again thanks for ur valuable vedios.
reply
Hello, sir.
Please make a vedio on.
Scaling of condensor evaporator in chillers,
Also best method and tools require for maintenance of water cooled chillers.
Thanks for ur all vedio,
Ur vedio so help full for me and others.
Sir we don't have much money to get tools
Sir, superheat in chiller, I can't understand
How to implement superheat data on small Ac for solving cooling problems.
Again thanks for ur valuable vedios.
reply
Gregory
I have a question. As the load decreases and the superheat decreases, what happens to the liquid refrigerant in the line between the pilot valve and the main valve that enables the main valve to close? Does it leak back through the pilot valve, or is their a bleed at the main valve that allows pressure to leak down? Thanks.
reply
I have a question. As the load decreases and the superheat decreases, what happens to the liquid refrigerant in the line between the pilot valve and the main valve that enables the main valve to close? Does it leak back through the pilot valve, or is their a bleed at the main valve that allows pressure to leak down? Thanks.
reply
Mohammed
Thank you for the information. I have a question, what do you mean by superheat? I bit you mean a superheated vapor. the thermal bulb which is located inside the suction line will sense the superheated vapor, but what I know is the status of the refrigerant after leaving the evaporator will be as a saturated liquid.
reply
Thank you for the information. I have a question, what do you mean by superheat? I bit you mean a superheated vapor. the thermal bulb which is located inside the suction line will sense the superheated vapor, but what I know is the status of the refrigerant after leaving the evaporator will be as a saturated liquid.
reply
Deepak
Thank you so much for the explanation: ) i just had one question, The refrigeration cycle starts with the suction stroke of compressor right? if yes then in that case how does the flow of refrigerant takes place? i mean does the evaporator is filled with the refrigerant? thanks again
reply
Thank you so much for the explanation: ) i just had one question, The refrigeration cycle starts with the suction stroke of compressor right? if yes then in that case how does the flow of refrigerant takes place? i mean does the evaporator is filled with the refrigerant? thanks again
reply
Shubham
1. What will happen if water droplets get into a centrifugal compressor?
2. What will happen if gas or vapour get into a centrifugal pump?
3. What will happen if we remove expansion valve from the centrifugal chiller or vapor compression cycle?
Thank you.
reply
1. What will happen if water droplets get into a centrifugal compressor?
2. What will happen if gas or vapour get into a centrifugal pump?
3. What will happen if we remove expansion valve from the centrifugal chiller or vapor compression cycle?
Thank you.
reply
MOHAMMED
Thanks for your very helpful video and i am very grateful for your work. I have a question, If the expansion controlled flow of refrigerant then why IGV inlet guide vanes are used in centrifugal chiller?
I hope you will clear my doubts.
reply
Thanks for your very helpful video and i am very grateful for your work. I have a question, If the expansion controlled flow of refrigerant then why IGV inlet guide vanes are used in centrifugal chiller?
I hope you will clear my doubts.
reply
Holman
Hi, I appreciate you help me with this doubt, The expansion valve decreases temperature and pressure because it increases the flow area or because it places a restriction for its passage, preserving after this restriction the same flow area?
reply
Hi, I appreciate you help me with this doubt, The expansion valve decreases temperature and pressure because it increases the flow area or because it places a restriction for its passage, preserving after this restriction the same flow area?
reply
meursault42
Enjoy your videos! From the novice perspective (me, I believe starting off with an explanation of the thermal expansion valve would have been a little easier since it's the simpler configuration
reply
Enjoy your videos! From the novice perspective (me, I believe starting off with an explanation of the thermal expansion valve would have been a little easier since it's the simpler configuration
reply
Artur
I think it's so cool that it's a totally mechanical system, no electronics (unless you have the EXV. Making it a robust the system. Awesome, kudos to the engineers that developed these systems.
reply
I think it's so cool that it's a totally mechanical system, no electronics (unless you have the EXV. Making it a robust the system. Awesome, kudos to the engineers that developed these systems.
reply
Scott
Why can air compressors deal with liquid when the compress air in the piston cavity but not refrigeration compressors, negating the fact for refrigeration liquid dilutes the oil?
reply
Why can air compressors deal with liquid when the compress air in the piston cavity but not refrigeration compressors, negating the fact for refrigeration liquid dilutes the oil?
reply
HVAC
Dude your videos are the best out there for HVAC industrial stuff no one has this type of explanation like this I highly recommend subscribing with the bell on lol
reply
Dude your videos are the best out there for HVAC industrial stuff no one has this type of explanation like this I highly recommend subscribing with the bell on lol
reply
Hoang
Thanks for your really great and helpful video, and can you advise what is a differences between Internal and External Equalizer Thermal Expansion Valve. Thanks
reply
Thanks for your really great and helpful video, and can you advise what is a differences between Internal and External Equalizer Thermal Expansion Valve. Thanks
reply
Heshwanth
Where does the refrigerant gas goes from the pilot expansion valve once it pushes the main expansion valve. How does it recoil? Can someone explain me
reply
Where does the refrigerant gas goes from the pilot expansion valve once it pushes the main expansion valve. How does it recoil? Can someone explain me
reply
hengchung1
hi this is great video. Could you also explain the relationship between the temperature and pressure to control the expatiation valve. Thank you.
reply
hi this is great video. Could you also explain the relationship between the temperature and pressure to control the expatiation valve. Thank you.
reply
Fathma
Sir I am new on this field, thats why I am little confused about, so my question is why there is two valve, pilot and main
reply
Sir I am new on this field, thats why I am little confused about, so my question is why there is two valve, pilot and main
reply
aissa
thank you very much sir. if you can tell us the most problems come on chiller, and if you can explain litll a screw chiller
reply
thank you very much sir. if you can tell us the most problems come on chiller, and if you can explain litll a screw chiller
reply
parvez
what is the right superheat temperature for this kind of machine.
I have 4 No's chiller which has different superheat
reply
what is the right superheat temperature for this kind of machine.
I have 4 No's chiller which has different superheat
reply
Benard
Hello engineering mind. com
Am Benard currently working in Qatar, I have a question Do u have HVAC school in Qatar
reply
Hello engineering mind. com
Am Benard currently working in Qatar, I have a question Do u have HVAC school in Qatar
reply
Vineeth
Hi can you upload the procedure for how to charge/Change refrigerant and oil to chillers? It will be of great help.
reply
Hi can you upload the procedure for how to charge/Change refrigerant and oil to chillers? It will be of great help.
reply
Rahul
This is nice video. Can you tell us how capillary tubes work as expansion device? I saw it in various Water coolers.
reply
This is nice video. Can you tell us how capillary tubes work as expansion device? I saw it in various Water coolers.
reply
Shimo
Hi Sir, Can you help me out, that how can get recover the Oil in Sump from Evaporator in Centrifugal chillers?
reply
Hi Sir, Can you help me out, that how can get recover the Oil in Sump from Evaporator in Centrifugal chillers?
reply
Shimo
Hi Sir, Can you help me out, that how can get recover the Oil in Sump from Evaporator in Centrifugal chillers?
reply
Hi Sir, Can you help me out, that how can get recover the Oil in Sump from Evaporator in Centrifugal chillers?
reply
Rayyan
Thank you sir, Video was so usefull
Sir, can you please upload any animated video how these vales works?
reply
Thank you sir, Video was so usefull
Sir, can you please upload any animated video how these vales works?
reply
Rodrigo
Good video! very clear, simple and with real examples, the key to learn any concepts in engineering!
reply
Good video! very clear, simple and with real examples, the key to learn any concepts in engineering!
reply
Add a review, comment
Other channel videos
13:39
