Hi all,(adsbygoogle = window.adsbygoogle || []).push({});

There is a block of ice (say 20 cm^3) sitting inside a box (50cm^3, constant volume) at very low P and low T (say P = 10^(-8) kPa and T = 100 K .... roughly ambient moon P and T).

There is a constant heat flux incident on the box. I want a 'path-way' (explicit phase transition regimes etc) that will take this ice block to high T (~ 500 K) and high P (~ 18 MPa), and quantify energy requirement in each step. The heat source is infinite. Please make any other assumption that may prove helpful.

My approach:

The given P and T is well below the triple point. If I heat the ice, it will increase its T under the same initial P. Once it hits the sublimation line, the energy input will convert it directly to vapor (under constant P, is this assumption valid?) .

Now, after everything is vapor, if I continue heating, I am not sure how to quantify the path-way in the P-T diagram. (Assuming ideal gas under constant V.... P has linear relationship with T but I can't tell anything about the slope). How does the P and T change now (after sublimation) under constant volume and constant heat source?

Please help me quantify this.

Many thanks !

(I was looking at XSteam and there is no data at low P and T.)

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Very low pressure and Temperature to high P, high T (constant volume, constant heat)

**Physics Forums | Science Articles, Homework Help, Discussion**