I have designed a container which is heated up and has to heat up some tube-coils of water inside of it. This container is filled with a fluid that can help store and transfer the heat received from the container to the tube-coils.
My plan was to find some material that I can easily buy and which is not very expensive to fill the $636cm^3$ container.
It has to have a high coefficient of heat transfer, high heat capacity and an operating temperature of at least the range of 10-400 degrees Celsius. I will also need to calculate how much the volume changes when it goes from around -35 to 500 degrees Celsius.
I also think a high density and if the material is non-toxic might be a plus.
Does anybody know any fluid that could be used for this or somewhere where I could find such information?