Rock Bed Heat Storage System

ϵ

1.

T

15.

k

1

1.

k

2

1.

y

0,1

5.

y

0,2

15.

y

1

(t)

y

2

(t)

A rock bed heat storage system for a room stores heat by circulating air heated by solar radiation during the day through an insulated layer of rocks. At night, when the temperature of the room decreases, a fan circulates the hot air into the room. The advantages of this are that rocks are cheap and their specific heat is high. Let

m

1

and

m

2

be the masses of the air and the rocks,

C

1

and

C

2

their specific heats,

A

1

the area of the walls and ceiling,

A

2

the interface between rocks and air, and

T

a

the temperature outside the room. The plots are the solutions for the air temperature

y

1

(t)

and the rock bed temperature

y

2

(t)

.