Melting Ice in Seawater: Cooling Steel on Seabed with 30kg Ice Block at -20degC

In summary, the question is asking at what temperature the steel can be cooled before the ice block placed on top of it is completely melted and dissolved. This answer cannot be determined solely by energy balance and will depend on the rates of heat transfer between the water, ice, and steel. The specific rates of heat transfer will determine the temperature of the steel at the moment when the ice is completely melted, as well as whether or not the ice and steel are affected by being on the sea bed.
  • #1
patfee
2
0
Using a 30kg cubic block Ice at -20degC, I want to cool down a piece of steel which is resting on the seabed. The mass of steel is 1kg and the ice block is place on top of the steel.
The current sea temperature as well as the steel temp is estimated at 12degC

Assuming that the piece of steel is not "heated" by the seabed, nor the sea water, the ice melts while cooling the steel.

Question is till what temperature can the steel be cooled before the ice is completely melted and dissolved.

I'm kinda lost here on the thermodynamics, since the "energy out" does not equal the "energy in" as the unlimited amount of seawater volume will melt the ice without increasing in temperature.

can someone push me in the right direction please.

thanks
Patrick
 
Physics news on Phys.org
  • #2
I am afraid you cannot find the answer from pure energy balance.
The answer will depend on the rates of heat transfer from the water to the ice and steel to the ice.
There will be a temperature gradient building up around the ice block.
During melting you have a non-equilibrium situation. Water, ice and steel have different temperatures. I understand that you want to know what will be the temperature of the steel (assuming it is uniform, which may be a good approximation for a good conductor) at the very moment when the ice is completely melted.
So the answer will depend on the specific rates of heat transfer.

Unless you want to wait until equilibrium is reached again and then everything will be pretty much 12 degrees.
 
  • #3
I am looking for the 'nub' of this question. Is the fact that the ice and steel are on the sea bed relevant to the question? (You say the steel is not heated by the sea bed or the sea water).
 

1. What is the purpose of cooling steel on the seabed with a 30kg ice block?

The purpose of cooling steel on the seabed with a 30kg ice block is to achieve a low temperature environment for the steel to be hardened. This process is commonly used in the oil and gas industry for the construction of offshore structures and pipelines.

2. How does the melting ice in seawater contribute to cooling the steel?

The melting ice in seawater absorbs heat from the steel, causing it to cool down. As the ice melts, it also releases cold water which further cools the steel. This process is known as the latent heat of fusion and is an effective way to achieve low temperatures.

3. What is the significance of using seawater instead of freshwater for this process?

Seawater has a lower freezing point than freshwater, which means it can reach lower temperatures before freezing. This makes it more effective for cooling steel. Additionally, seawater is readily available in marine environments, making it a convenient and cost-effective choice for this process.

4. What are the potential challenges of using this method for cooling steel on the seabed?

One potential challenge is the variability of seawater temperatures. The temperature of seawater can vary depending on location, depth, and season. This can affect the cooling process and may require adjustments to the amount of ice used. Another challenge is the potential for seawater to corrode the steel, which must be addressed through proper insulation and corrosion protection measures.

5. Are there any other applications for this technique besides cooling steel on the seabed?

Yes, this technique can also be used for other industrial processes that require low temperatures, such as in the food and beverage industry or for medical and scientific research. It can also be used in the construction of ice roads and in the preservation of fresh produce during transport.

Similar threads

  • Biology and Chemistry Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
9
Views
2K
Back
Top