Heat Storage

What is your application? Sounds like a hot water tank!!??

It could be said as hot water storage. But it's stratified sensible heat storage, means that while there is 70 ºC water in the tank, the tank is charged from the top and up part of the tank filled with 90 ºC while in the down levels there is 70 ºC water.

It is much more complex then a hot water tank I think.

You wrote:-

It is much more complex then a hot water tank I think.

I don't think, I know! it is far more complicated and you need to supply complete details if any help is to be easily forthcoming....

As I said it is a stratified heat storage.. connected to a district heating system directly. district heating system is working at 70 (return) - 90 (supply) ºC at 25 bar..

What can I say more? Please ask me what I can say..

I see that you already did,

Thanks.

Wangito.

Once, (many years ago) I have been asked the same question.(If I understood you well)

I have built a pilot plant (50Gal.) round tank, where the bottom part was kept at 40ºC And the top was supplied by a 75°C water heater. and mixed with cold water supply simultaneously to satisfy variable demand situations. This was done by request of a child care center where they wanted warm water at fixed temp. without the kids messing with dual command mixing taps, mainly for safety reasons. Single command lever taps were unknown yet as a mass consumer product.

We did the following: a Round pressure vessel with a floating funnel shaped conical disc. The 75°c water, were poured over the upper side of the disc, that had an orifice in it's center through which the 75°c water were supplied and mixed with the 40°c water (lower part.) The cold water were supplied through a floating flexible tube mounted just under the floating disc using rotating sprinkler type assembly. both which were controlled by a small temp. controller having sensors at the various downstream points. solenoids valves check valves etc. It did work pretty well. They did use the design for a while (500Gallon tank) until a new center was built. I wish I had kept my notes...

Hope it may help.

Wangito.

Ok Try this

http://www.delphion.com/details?pn=US03720198__

Very interesting theme...

If you register it will bring aboard many knowledgeable guys here that otherwise will refrain from participating. It's easy, and best of all, it's free.

Wangito.

The person who asked the question is me.. Sorry for misnaming at first post.. :(

Try to use a latent storage system: fill an tank with a Parrafin which melts in the temperature zone which you need to cover just below the 90°C.

Through this tank you guide a pipe that contains the water from the district heating system. This simplifies the design of the tank, as pressurised can be very expensive when big. (25Bar is a decent pressure)

The amount of parrafin needs to be calculated based on the heat needs and storage needs that is requested.

succes,

You are right. Then tank with 25 bar is huge and thickness of the pressure vessel is thick. By choosing the proper material the thinckness become in sizes to be manufactured. Choosing the stratified sensible storage system is hard way for me.

Bu isn't parrafin expensive in operational cost? parrafin loose its storage property by time so that it must be changed. So stratified sensible storage is choosen according to its low operational cost.

Aren't there any study on sensible heat storage? Or do someone has contacts with a firm that design or operate.

As long as you stay withing the nominalk limits of use, Parrafin should keep it's function.

It solidifies and melts with heat being extracted and added. I don't know why this would change over time.

A benefit would be that you can keep oxigen away from the liquid.

I don't remember the source but I know that phase changing heat storage metarials loose their function with time.. Also, I'm going to investigate the phase changing heat storage metarials, after. Thanks for your interest.

But Again I need any information about stratified sensible heat storage systems.. Something you know about: please write it to me.

Re: Heat Storage? The best guide available I have found for information on Heat Storage, is to search on Google for Steam Accumulators and find latent heat storage, I think on the third page. I hope this will help you. Conserving thru Efficiency. DonnieH