Great video. Unlike some marketing materials from D, which are so biased. Danfoss, stick to your technical side and you will be fine (i.e. technical people will put your products in their plans and implementations). Thank you once again for sharing.
Thanks for the feedback, we'll pass the request for Fahrenheit metrics along to our team. You can learn more about CO2 refrigeration on our Danfoss Learning Hub: www.danfoss.com/en/service-and-support/learning/climate-solutions-learning/
In a case when the pressure is above the critical pr (1800psi) but temp is below Critical temp, co2 continues to be in liquid state. Now if temp is raised to 45deg C, co2 attains scf state. In the temp is now lowered below Critical temp without releasing the pressure, will co2 again change to liquid state ? If we shake the cell, can we hear splashing sound ?
Hi. Amazing video!! I got curious about 4:52. I understand you need to go down the liquid-vapor line so that the two phases coexist, meaning boiling point. As you lower the pressure, the temperature decreases. How is it that heat is lost from the liquid when boiling as you go down the line? If we go up the line, as you increase the pressure you need to add heat to the liquid to meet the boiling point, but when you go down heat must be lost from the liquid.
Since it's a lab experiment, the high-pressure vessel's temperature is also controlled externally. So, we reduce the temperature to balance the liquid-gas line while reducing the pressure.
On the CO2 ph-Diagram, I do not understand the Enthalpy measurement on the X-axis. How can CO2 be in a state of minus kj/kg? You cannot have minus energy in a property, e.g. -1 kj/kg, similar to -1 kelvin not being able to exist. I think I'm missing something here, any help would be appreciated.
There is no natural zero-point for energy (and therefore neither for enthalpy). You choose yourself where you want enthalpy to be zero. Traditionally, some organization have tried to set standard values (ASHRAE, IIR,…), but there is no fixed convention. Luckily, this doesn’t really matter as we are always looking at differences in enthalpy - and when you look at differences, the zero-point doesn’t matter.
Because of the instant crystallization of the liquid, the light shifted so fast that the camera could not react fast enough, therefore it looks as if a flash happened, but that's not the case. It was just a trick of the light.
Complete CO2 Sistama drive.google.com/drive/folders/1ze5gIfvn8WO19mIICzdOeWWwCEFCoK5q?usp=sharing Transcritical CO2 ice Rink drive.google.com/drive/folders/1yZiYvh6JLjQ44wmAJh7tHN5zXn2zGqIz?usp=sharing
Hi Milav, good question: It's not that the triple- or critical points are of any special benefits, that's just the "nature" of a brilliant natural refrigerant with practically no GWP and ODP, a truly environmentally friendly refrigerant. Working with CO2 in HVAC and refrigeration applications will however require quite some special know-how. Jens Andersen Danfoss Cooling
In some applications it is a benefit (i.e. extraction of coffeing using supercritical co2 can be done at low temperature), but sometimes a drawback (high pressures need to achieve efficient thermodynamic cycle for refrigation. There are other tradeoffs. That is why we have many refrigerants. CO2 is just nice because it has no ODP, GWP=1, and is in general safe and well established. NH3 not so good.
Our expertise is primarily on sea-level solutions. If you're curious about conditions beyond the atmosphere, I'm sure our friends at the ESA and NASA would love to help. 🚀
Great video. Unlike some marketing materials from D, which are so biased. Danfoss, stick to your technical side and you will be fine (i.e. technical people will put your products in their plans and implementations). Thank you once again for sharing.
Thanks for liking the video and for your suggestion.
Great Video, saw three phase of refrigerant Co2 for first time. So much informative that will have see this for two to thee times. WOW ONCE AGAIN
Hi Aftab, Thank you for your comment. It's always great to get positive feedback. Have a nice day :-)
Pretty cool video, I wish there was with Farenheit numbers too, I am not too familiar with Celsius, thanks
Thanks for the feedback, we'll pass the request for Fahrenheit metrics along to our team. You can learn more about CO2 refrigeration on our Danfoss Learning Hub: www.danfoss.com/en/service-and-support/learning/climate-solutions-learning/
In a case when the pressure is above the critical pr (1800psi) but temp is below Critical temp, co2 continues to be in liquid state. Now if temp is raised to 45deg C, co2 attains scf state. In the temp is now lowered below Critical temp without releasing the pressure, will co2 again change to liquid state ?
If we shake the cell, can we hear splashing sound ?
Great! Only one question is it real time videos or fast motion? Especially 6:02, I've found in comments it's real time. Is it true?
Yes it is the real time video. :)
Hi. Amazing video!! I got curious about 4:52. I understand you need to go down the liquid-vapor line so that the two phases coexist, meaning boiling point. As you lower the pressure, the temperature decreases. How is it that heat is lost from the liquid when boiling as you go down the line? If we go up the line, as you increase the pressure you need to add heat to the liquid to meet the boiling point, but when you go down heat must be lost from the liquid.
Since it's a lab experiment, the high-pressure vessel's temperature is also controlled externally. So, we reduce the temperature to balance the liquid-gas line while reducing the pressure.
Danfoss Cool thank you. I really appreciate it!
@@issac1071 You're welcome. No trouble at all. :)
On the CO2 ph-Diagram, I do not understand the Enthalpy measurement on the X-axis. How can CO2 be in a state of minus kj/kg? You cannot have minus energy in a property, e.g. -1 kj/kg, similar to -1 kelvin not being able to exist. I think I'm missing something here, any help would be appreciated.
Our CO2 Jedi Master is currently out of the office. We'll ask him when he gets back in and post his response here. 👍
There is no natural zero-point for energy (and therefore neither for enthalpy). You choose yourself where you want enthalpy to be zero. Traditionally, some organization have tried to set standard values (ASHRAE, IIR,…), but there is no fixed convention.
Luckily, this doesn’t really matter as we are always looking at differences in enthalpy - and when you look at differences, the zero-point doesn’t matter.
@@DanfossClimate Brilliant, thank you for replying. It's not often you get an in depth answer from people in an industry. Much obliged.
@@drinkurprunejuice4007 We're here to help! Reach out anytime.
Yes, as already answered, enthalpy is a property that requires a reference state to be defined.
As the liquid turns to solid at 6:02 what is the flash?
Because of the instant crystallization of the liquid, the light shifted so fast that the camera could not react fast enough, therefore it looks as if a flash happened, but that's not the case. It was just a trick of the light.
Complete CO2 Sistama
drive.google.com/drive/folders/1ze5gIfvn8WO19mIICzdOeWWwCEFCoK5q?usp=sharing
Transcritical CO2 ice Rink
drive.google.com/drive/folders/1yZiYvh6JLjQ44wmAJh7tHN5zXn2zGqIz?usp=sharing
Great Job，Amazing！THX！
What are the exact benefits of high triple point and low critical point of CO2?
Hi Milav, good question:
It's not that the triple- or critical points are of any special benefits, that's just the "nature" of a brilliant natural refrigerant with practically no GWP and ODP, a truly environmentally friendly refrigerant. Working with CO2 in HVAC and refrigeration applications will however require quite some special know-how.
Jens Andersen
Danfoss Cooling
In some applications it is a benefit (i.e. extraction of coffeing using supercritical co2 can be done at low temperature), but sometimes a drawback (high pressures need to achieve efficient thermodynamic cycle for refrigation. There are other tradeoffs. That is why we have many refrigerants. CO2 is just nice because it has no ODP, GWP=1, and is in general safe and well established. NH3 not so good.
I want to recreate that chamber could anyone give me some advice for materials?
if co2 sublimes where the carbon goes ,o2 goes to air ,but carbon where does it go ? 😉
do you think it is possible for co2 to be in a frozen state at 100km up in the I-on-no-sphere?
Our expertise is primarily on sea-level solutions. If you're curious about conditions beyond the atmosphere, I'm sure our friends at the ESA and NASA would love to help. 🚀
Am I the only one having odd audio ?
It is a near critical voice having density fluctuations.
Nice, it would be nice if the eco chamber could be eliminated.
Squalo
Number one my friend🎉
This demo has nothing to do with the atmosphere.