Ice Bank Tank for Chilled Water

[Samarjit Sen]

Could some one tell me wether an Ice Bank Tank could be replaced with a Shell & Tube Chiller or a Plate Heat Exchanger. The temperature of water is required at 4 Deg. C with water coming at 30 Deg. C. The required flow is 35 lpm. This is required for a process chilling. The requirement is for an Ice Bank Tank, and I am thinking that instead of Ice Bank Tank, why don't I install a compact chilling plant.

Advice and suggestions shall be highly appreciated.

[LRAC]

Hi Samarjit Sen

can't think of any reasons why you can't use a plate heat exchanger, but other members mgiht have a diffferent view.

Regards
Lrac

[US Iceman]

One of the biggest advantages of using ice for thermal storage is the the large volume of stored capacity that is available.

Sure, a small chiller package will work but it will probably be a larger cooling capacity, rather than that of the refrigeration system for the ice bank.

It depends on several variables:

How much cooling is required instantaneously with the ice bank?

How much time is available to build the ice, and how much time is required for the actual process cooling load.

If there are large time periods between the process cooling cycle requirements, then an ice bank is preferable in my mind. This would also offer the smallest refrigeration system as you are storing the cooling (in ice) over a long time duration.

If the process cooling is almost continuous, then a chiller water system with a chiller would probably be a better choice. In this case, the refrigeration system could be much larger (than the ice bank system), since you are meeting the cooling demand as it occurs.

[Electrocoolman]

I understood one reason for using an ice bank was that you could produce ice overnight on cheap rate power and then use the ice to meet or supplement demand during the day. (Load lopping).
In this way you can run a smaller chiller during the day and another small one at night with a lower set point to freeze the ice. More efficient.

[US Iceman]

I understood one reason for using an ice bank was that you could produce ice overnight on cheap rate power and then use the ice to meet or supplement demand during the day.


That's true also. Areas of high demand charges are one those things that make ice storage very economical.

However, not all ice banks use chillers. This is something of a relatively new idea. Until this started almost all of the ice bank storage systems used flooded or recirculated liquid feed (mostly ammonia).

[Samarjit Sen]

In our country the rate of electricity is the same round the clock. I am trying to think in terms of having a compact plant with more efficiency. A plant of 35 lpm is small and the refrigeration load in this particular case will not be much. I had assessed the load at 56 kw at -5 Deg. C Te and 35 Deg. C Tc with R 22 as a refrigerant.

[NoNickName]

Probably the ice tank was installed or required because of the high delta T in/out. S&T and PHE require a minimum flow to ensure turbulence, and as known flow is inversely proportional to delta T. There may not be exchangers for that capacity and that delta T on the market, which would require a custom made exchanger.

[Josip]

Hi, Samarjit Sen :)


Could some one tell me wether an Ice Bank Tank could be replaced with a Shell & Tube Chiller or a Plate Heat Exchanger. The temperature of water is required at 4 Deg. C with water coming at 30 Deg. C. The required flow is 35 lpm. This is required for a process chilling. The requirement is for an Ice Bank Tank, and I am thinking that instead of Ice Bank Tank, why don't I install a compact chilling plant.

Advice and suggestions shall be highly appreciated.


Sure, a small chiller package will work but it will probably be a larger cooling capacity, rather than that of the refrigeration system for the ice bank.


In this way you can run a smaller chiller during the day and another small one at night with a lower set point to freeze the ice. More efficient.

Agree with guys...

It is not so small capacity and speaking about optimization I will suggest to stay with Ice bank.

Best regards, Josip :)

[Peter_1]

However, not all ice banks use chillers. This is something of a relatively new idea. Until this started almost all of the ice bank storage systems used flooded or recirculated liquid feed (mostly ammonia).
We've one (Packo) and it's a DX one on R404a.
But another good example is the Cristopia Energy Systems from France (VEnce) with the frozen balls in the storage containers

[US Iceman]

I had assessed the load at 56 kw at -5 Deg. C Te and 35 Deg. C Tc with R 22 as a refrigerant.


But what was the capacity of the refrigeration system on the ice bank? My guess is the capacity was considerably smaller.

Although, the packaged chiller would offer a smaller installation in all probability.

[absrbrtek]

The ice tank allows you to use a smaller chiller and it also is used as a buffer tank most likely. I have seen chillers installed in low temp applications and the chiller is constantly cycling due to load changes. I have installed buffer tanks to stop the short cycling, I would leave the tank.

Is the chiller pumping in and out of the tank on its own loop? Is the load from the tank on a seperate loop?

[Samarjit Sen]

The application for which I am thinking to provide a chilling plant than an Ice Bank Tank, is that the chilled water from the chiller shall cool milk after pasteurising in batches. The chilled water flow is 35 lpm and the refrigeration capacity of the system is 56 kw. I propose to maintain the Te at -8 Deg. C and the Tc at 35 Deg. C.

[Josip]

Hi, Samarjit Sen :)


The application for which I am thinking to provide a chilling plant than an Ice Bank Tank, is that the chilled water from the chiller shall cool milk after pasteurising in batches. The chilled water flow is 35 lpm and the refrigeration capacity of the system is 56 kw. I propose to maintain the Te at -8 Deg. C and the Tc at 35 Deg. C.

That capacity is per/h but I think you have much more milk to cool ;) but only in the morning i.e. once per day if I am right..


If there are large time periods between the process cooling cycle requirements, then an ice bank is preferable in my mind. This would also offer the smallest refrigeration system as you are storing the cooling (in ice) over a long time duration.

Attached is a photo of special ice bank silos in one dairy. The same compressor is running on day time for AC purpose and over night to make ice (good optimization;) ).

Best regards, Josip :)

[monkey spanners]

Hi Samarjit Sen

All of the ones ive seen have used ice bank systems, but these were small scale dairies based on the farm (200L-10,000L a day).
How continuous is the flow of milk through the pasturiser? If they stopped the flow to change the temperature recorder paper for example and the chiller goes off and they start the milk flow again while the chiller is waiting to start (6-10 minutes between starts?) would this cause problems?
Maybe you would need a buffer tank to hold enough chilled water to run the pasturiser if the chiller is cycling off and on.
I'd vote for an ice builder, but thats because they are what im used to:D

Cheers Jon

[kevinlewis1970]

I worked for a company who removed a a large ugly ice bank. W e replaced it with a WITT SPRAY CHILLER. It is basically a shell and tube heat exchanger with a liquid pump at the bottom. The pump pumps liquid ammonia to a a pipe internally above the tube bundell and sprays a fine mist of ammonia over the tube which can give you temps as low as 0.7'C with water at a required flow rate.
W e used a Mycom screw and a small evaprative condensor. The plant was very compact and extremly efficent with a 120kg ammonia charge.

[Samarjit Sen]

The milk shall be chilled throughout the day. The total capacity of the milk which has been estimated by the user shall be 7 to 10000 liters per day. The operation shall continue for the working period which may be only 12 hours at the most in the day time. There shall be no operation in the night.

The process shall be continuous as there are are no temperature recorder and there is no need to change any paper.

I do not think that the quantity of milk shall be more than 5000 liters per day. I have considered the maximum. Further the milk shall be cooled in batches, which means that there shall time when the chiller shall be running on no load.

[bakianathan]

where can i learn the basics of IBT system.

[pra1968]

I worked for a company who removed a a large ugly ice bank. W e replaced it with a WITT SPRAY CHILLER. It is basically a shell and tube heat exchanger with a liquid pump at the bottom. The pump pumps liquid ammonia to a a pipe internally above the tube bundell and sprays a fine mist of ammonia over the tube which can give you temps as low as 0.7'C with water at a required flow rate.
W e used a Mycom screw and a small evaprative condensor. The plant was very compact and extremly efficent with a 120kg ammonia charge.

Dear Kevinlewis1970
can u explain more abt it?
I m also intrested in it to use for chilled water !!!

[Lowrider]

I don't know about India, but in the Netherlands they do not allow the use of glycol without a dubble separation from the foodstuff. Glycol will have to be used in this case. If one uses an ice buffer, this can also be used as a separation by running the proces water through the ice banks.

But I could be way off track here!

[gueito]

Hi! I'm designing a refrigeration system for a dairy industry. I was thinking of using an ice bank but I don't know which cycle to use. Do I need to use a booster or only one compressor? Can anybody provide me with a drawing of the cycle? I need a load of 55 TR.
Thank you

[Magoo]

What ever all the above. The only advantage of ice banks is peak loading in short time frames. So you build ice in the ice bank, more than likely at off peak power loadings, and then consume the ice during production.
Load profiles are the real criteria.
magoo

[Shibhrac]

What i know is that ice banks are usually installed to get advantagues of low electricity cost during night. Another reason which make ice bank worth installing that, if the peak hours of a building required big plant to overcome heat load in a very limited time during the day . An example for that is a factory crowded messhall where the need of cooling is only in the time where workers are enjoying their hot meals. In that case ice bank offers capital cost saving and low power consumption as the build up of ice is usually made during night when the electricity cost is lower. It's also worth installing in milk producing farms.

[mad fridgie]

Another option is binary ice, (slush)
Higher averaged COP than a standard ice builder, reduced heat transfer area, piping and pumps required,

[mbc]

Hi
low electricity cost during night +
ice banks is a suitable for peak loading in short time
Also in ice bank your temperature can comes to near 0 without damaging Evap. but in chiller you cannot go temperature of water less than +5 . Your evap. temperature does not allow you and it is very dangerous

[Bhagwan Harani]

Ice Bank System is selected where load is 4-6 Hrs/day.Refrigeration syatem is selected of capacity 20-25% & it runs for 20-24 hrs/day. Refrigeration is stored in form of ICE,which melts on load.

[Bhagwan Harani]

Hi! I'm designing a refrigeration system for a dairy industry. I was thinking of using an ice bank but I don't know which cycle to use. Do I need to use a booster or only one compressor? Can anybody provide me with a drawing of the cycle? I need a load of 55 TR.
Thank you
What is quantity of Milk @ what is time in which U want to cool

[Bhagwan Harani]

What is quantity of Milk @ what is time in which U want to cool
what quantity of milk U want to cool & time