Iceberg to Capetown

[Enthalpy]

1200kg Ice storage to cool a detached house for a week can look like this:

The ice stays in the storage. Air from the house or filtered from the atmosphere or passes through a heat exchanger at the tank's bottom. Regulators in the rooms suck as much cold air as needed locally, they blow and mix it as needed, and the ice melts accordingly.

0.2m foam plus the metal at the top opening leak 43W or 62kg=5% in a week. Flowing the arriving air first around the insulation would reclaim the leaked cold, an opportunity for thinner cheaper foam. The heat exchanger needs roughly 10m² fins of banal alloy. To clean the exchanger, the foam around it is removable.

2mm steel weigh around 400kg so series production may cost a bit over 1k€ a piece.

Some sort of key and measure of the delivered quantity, shared by the supplier and the user, seem necessary. The meltwater can be useful in many gardens.

==========

If the ice comprises blocks of very different sizes, more can pack in a tank, just like concrete comprises stones, pebbles and sand. Easily done when mining the iceberg.

Delivery trucks, reasonably manoeuvrable, can carry around 25t ice, so they should make a rotation for <<133€, easier than the previous estimate. If a truck makes 6 rotations a day, 20 days a month, it looks feasible, but remains a significant cost share.

Marc Schaefer, aka Enthalpy

[Enthalpy]

On 9/25/2018 at 7:51 AM, Kevin Mulisa Isaya said:

the bergs will periodically roll to adjust as the ice below surface melts quicker then the ice above the water line. Having tow lines pulled over or under the burg could be quite exciting for the crews involved and would likely lead to their disconnection by breakage or intervention that would then result in considerable delays for reattachment, and putting crews up close to reattach the lines would be almost criminally irresponsible if you could find anyone brave enough to get that close to an unstable massive block of ice of those proportions.

Kevin Mulisa Issaya

Please see my second answer there
https://www.scienceforums.net/topic/116226-iceberg-to-capetown/?do=findComment&comment=1071764
I suppose professionals know better answers.

On 9/25/2018 at 1:46 AM, mistermack said:

[...] Maybe, you could enclose the berg in a gigantic plastic sack, so that as you tow it northwards, you don't lose water, and it gradually melts. So that by the time you got to the destination, all you need to do is pump the melted water out of the sack, as it is required.

Please see my fourth answer there
https://www.scienceforums.net/topic/116226-iceberg-to-capetown/?do=findComment&comment=1071764
I consider closing the bottom when arrived. Moving a sac of water in water can be cumbersome.

But presently, I prefer to lose the molten water, mine the ice once arrived and transport it solid to the land. Whether storage shall be liquid or solid depends on the use.

On 9/25/2018 at 5:57 AM, arc said:

[...] How about using geothermal heat at the source to generate the electric power for the processing and melting of the ice that would then be loaded into massive bladders that floated at almost neutral buoyancy.  They would be sent off with autonomous guidance systems operating electric propulsion systems powered from solar voltaic receptors integrated into the bladders surface. They would be monitored from satellite and make up for their smaller volume and slow progress by being very low cost to operate and one of many in a vast fleet that would regularly arrive and then act as the destination's storage facility, no need to pump it into tanks on shore. They would just need to hook up a hose pipe and draw directly into the distribution system.  The bladders would then be stacked on autonomous barges to be driven back to the source. 

Hey, you think I and my investors are going to let you have this whole market for yourself?!!!

Bladders have been considered to transport sweetwater over the Ocean. Whether the source is an iceberg shouldn't change much, since melting is harder to prevent than to encourage. You have a whole Ocean full of heat for that.

I have doubts about solar energy at 40°, 50°, 60° South. Wind should be more dependable there.

Autonomous: I have absolutely nothing against. That's more interesting for smaller transport units. If downsizing to 300 000 t makes economic sense, maybe a hull can replace the bladder, and then movement becomes more natural, including with sails.

I have no investors nor plan to earn money with that. That's a reason why I put it on the Web. Feel free to become a billionaire with the idea. Don't forget in your business plan the few technical subdetails to be solved.

Edited October 11, 2018 by Enthalpy

[Enthalpy]

The thermal conductivity of dry sand is rather 0.25W/m/K, so over 300 days, 1m thick sand would let melt only 3% of the the 1000m long, 190m base, 90m high ice dump suggested on September 30, 2018.

Sorting the sand to keep only one grain size may reduce the thermal conductivity.

==========

Some places like the North American Great Lakes region have icy winters, hot summers and a rich big population. Insulated dumps can keep ice from winter to summer to sell for the already described air conditioning.

One source of ice could be the lakes themselves.

Distribution of the ice is again a significant cost contribution. Suburbs, near to the ice dump and where trucks circulate better, ease that.

The many short rotations enable electric trucks easily. Swap the batteries if necessary to save time.

Marc Schaefer, aka Enthalpy

[swansont]

2 hours ago, Enthalpy said:

The thermal conductivity of dry sand is rather 0.25W/m/K, so over 300 days, 1m thick sand would let melt only 3% of the the 1000m long, 190m base, 90m high ice dump suggested on September 30, 2018.

Sorting the sand to keep only one grain size may reduce the thermal conductivity.

==========

Some places like the North American Great Lakes region have icy winters, hot summers and a rich big population. Insulated dumps can keep ice from winter to summer to sell for the already described air conditioning.

One source of ice could be the lakes themselves.

Distribution of the ice is again a significant cost contribution. Suburbs, near to the ice dump and where trucks circulate better, ease that.

The many short rotations enable electric trucks easily. Swap the batteries if necessary to save time.

Marc Schaefer, aka Enthalpy

This is basically what they used to do. Cut blocks of ice out of lakes, store them packed in sawdust, and sell ice throughout the warmer months. Some folks shipped ice to tropical places. 

Before electric refrigerators there were iceboxes. 

[DrP]

This thread reminds me of Richard Pryor in the movie 'Brewster's Millions'.   He has to spend 30 million in 30 days so he looks for hair brained investments...  Some guy comes in with a plan to cut away the back of ice burgs in the Artic and install them with out board motors then drive them down to Africa.  Every one tells him to get out, but Brewster gives him a million to invest in it thinking it would be a sure way to loose a million....  trouble is the guy come back a total success and makes him millions more.  'tis a silly film.

[Carrock]

Much earlier, Four D. Jones in the Daily Express had a similar idea. He ended up with an ice cube and a small snowstorm in the Sahara Desert.

The only other exploit I remember was when Four moored a rowing boat to Land's End and towed Britain south for the winter. A technical success of course but it didn't end well.

A good introduction to science for someone just learning to read....

[swansont]

12 hours ago, swansont said:

This is basically what they used to do. Cut blocks of ice out of lakes, store them packed in sawdust, and sell ice throughout the warmer months. Some folks shipped ice to tropical places. 

Before electric refrigerators there were iceboxes. 

A lot of this was covered in a PBS special from a decade ago. NOVA: Absolute Zero

https://www.scienceforums.net/topic/28276-nova-absolute-zero-on-pbs-in-usa/ 

Also described in a wikipedia article

https://en.wikipedia.org/wiki/Ice_trade

 

[druS]

On 10/8/2018 at 3:43 AM, Enthalpy said:

1200kg Ice storage to cool a detached house for a week can look like this:

The ice stays in the storage. Air from the house or filtered from the atmosphere or passes through a heat exchanger at the tank's bottom. Regulators in the rooms suck as much cold air as needed locally, they blow and mix it as needed, and the ice melts accordingly.

 

Thermal storage for air-conditioning is not new, it's a little more complex than your scheme but essentially you've covered the basics.  There needs to be a method of moderating the temperature of the air being cooled - it may be a more efficient to use very cold air but there are limitations around thermal comfort and people reacting to cold drafts.

I haven't seen systems which bring in external ice though there is no reason not to - short of materials handling logistics.

Generally the way that commercial systems work is to use cheap electricity in off peak (night time) when there is a lessor requirement for cooling, to produce ice in stead. And then us the ice for cooling during peak (day time). It does help emissions/carbon etc as it reduces peak load and helps flatten power consumption. The generators are more efficient when closer to peak than at low load.

Alternatives are storing chilled water and also "phase change" systems - typically CO2/dry ice.

[Enthalpy]

On 10/18/2018 at 2:21 AM, swansont said:

This is basically what they used to do. Cut blocks of ice out of lakes, store them packed in sawdust, and sell ice throughout the warmer months. Some folks shipped ice to tropical places. 

Before electric refrigerators there were iceboxes. 

Yes. My parents still had an icebox for camping when I was a kid and the last ice age had just finished. A mobile seller brought water ice or carbon dioxide ice.

Cooling a whole house is a bigger scale, like 700W mean cooling power, maybe 20* more than a fridge. Electricity for a fridge is cheap and it achieves -8°C in the freezer, but air conditioning for a house is expensive, it heats the whole city, and emits significant carbon dioxide indirectly.

The whole challenge is to make the commercial activity sensible now despite it was abandoned half a century ago. For much bigger amounts, with better machines, and good organization. Frequent deliveries by truck might become a nuisance, I hope electric motors make the moves more acceptable.

Sawdust was a damn good idea, but I doubt we found the proper amount for an ice dump 1000m long, 190m base, 90m high. My best guess is a cheap, abundant material found everywhere - sand, even though a fair insulator. Fortunately, the size eases insulation, due to volume versus surface.

On 10/20/2018 at 5:29 AM, druS said:

Thermal storage for air-conditioning is not new, it's a little more complex than your scheme but essentially you've covered the basics.  There needs to be a method of moderating the temperature of the air being cooled - it may be a more efficient to use very cold air but there are limitations around thermal comfort and people reacting to cold drafts.

Happy to have your approval! As for moderating the temperature of the blown air, see my:
"Regulators in the rooms suck as much cold air as needed locally, they blow and mix it as needed"
there https://www.scienceforums.net/topic/116226-iceberg-to-capetown/?do=findComment&comment=1073797

On 10/20/2018 at 5:29 AM, druS said:

[...] commercial systems [...] use cheap electricity [during night], to produce ice [used] for cooling during [daytime]

Sure. But as things look, bringing a complete iceberg or storing ice from a lake is cheaper and takes far less energy than producing the ice, so I have more intellectual appetite for the more ambitious option.

The consumer's investment is also cheaper if using ice already produced. The storage tank could even belong to the ice supplier or be leased like cell phones are. To offer a completely new operation, I imagine that the supplier must provide all the elements at once.

Edited October 24, 2018 by Enthalpy