▎ 摘　　要

NOVELTY - The solar heat exchanger has a fused quartz glass tube which is provided with a graphene foam (5) and water (4) to be heated by solar energy that is in direct contact with the grapheme foam. The sunlight heat is directly absorbed by graphene foam and is transferred into water by direct contact, while maintaining a vacuum (3) between outer and inner tubes (1,2). USE - Solar heat exchanger. ADVANTAGE - The vacuum is maintained in the space between the inner and outer tubes, so as to minimize the heat losses. Thus, the heat absorption of the solar heat exchanger can be maximized efficiently. The overall efficiency of the solar heat exchanger can be improved efficiently. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a graphene foam. DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view illustrating the sunlight entering the heat exchanger and heat absorption and heat transmission into the water. Outer and inner tubes (1,2) Vacuum (3) Water (4) Graphene foam (5) Graphene coating (6)