Low-melting point inorganic nitrate salt heat transfer fluid
View Patent ↗A low-melting point, heat transfer fluid made of a mixture of four inorganic nitrate salts: 9-18 wt % NaNO 3 , 40-52 wt % KNO 3 , 13-21 wt % LiNO 3 , and 20-27 wt % Ca(NO 3 ) 2 . These compositions can have liquidus temperatures less than 100 C; thermal stability limits greater than 500 C; and viscosity in the range of 5-6 cP at 300 C; and 2-3 cP at 400 C.
1. The composition comprising in Mol %, cation basis:
16 mol % NaNO 3 ,
47 mol % KNO 3 ,
25 mol % LiNO 3 , and
12 mol % Ca(NO 3 ) 2 .
2. The composition of claim 1 , wherein the liquidus temperature is less than 100° C.
3. The composition of claim 1 , wherein the thermal stability limit is greater than 500° C.
4. The composition of claim 1 , wherein the viscosity is 5-6 cP at 300 C; and is 2-3 cP at 400° C.
5. The composition comprising in Mol %, cation basis:
20 mol % NaNO 3 ,
38 mol % KNO 3 ,
30 mol % LiNO 3 , and
12 mol % Ca(NO 3 ) 2 .
6. The composition comprising in Mol %, cation basis:
11 mol % NaNO 3 ,
50 mol % KNO 3 ,
27 mol % LiNO 3 , and
12 mol % Ca(NO 3 ) 2 .
7. The composition consisting essentially of in Mol %, cation basis:
16 mol % NaNO 3 ,
47 mol % KNO 3 ,
27 mol % LiNO 3 , and
10 mol % Ca(NO 3 ) 2 .
8. The composition of claim 7 , wherein the liquidus temperature is less than 100° C.
9. The composition of claim 7 , wherein the thermal stability limit is greater than 500° C.
10. The composition of claim 7 , wherein the viscosity is 5-6 cP at 300 C; and is 2-3 cP at 400° C.
11. The composition consisting essentially of in Mol %, cation basis:
20 mol % NaNO 3 ,
38 mol % KNO 3 ,
30 mol % LiNO 3 , and
12 mol % Ca(NO 3 ) 2 .
12. The composition consisting essentially of in Mol %, cation basis:
11 mol % NaNO 3 ,
50 mol % KNO 3 ,
27 mol % LiNO 3 , and
12 mol % Ca(NO 3 ) 2 .
13. A composition, comprising in Mol %, cation basis:
14 mol % NaNO 3 ,
49 mol % KNO 3 ,
20 mol % LiNO 3 , and
17 mol % Ca(NO 3 ) 2 .