DESIGN OF ROCK PILES FOR GREENHOUSE ENERGY STORAGE

Most solar greenhouses based on heated air use rock piles as the thermal store, and the design of such rock piles is becoming increasingly important.

There are four important design decisions to be made.
These are

1. Direction of air flow through the rock pile.

2. Rock pile volume.

3. Size of rock particles.

4. Height and cross sectional area of rock pile.

The suggested design approach is to make an initial calculation of the required rock pile volume, choose a rock particle size, and then carry out a detailed analysis of the performance of the rock pile.
From this the distribution of heat in the rock pile at any time can be obtained, together with the pressure drop resulting from the flow of air through it.
If the results of these calculations shows that heat distribution in the rock pile is unsatisfactory and results in unacceptable air temperatures emerging from it, or if the pressure drop is excessive, the calculations are repeated for an alternative rock particle size and/or alternative rock pile shape.

Energy Conservation and Solar Energy Utilization in Horticultural Engineering

K.V. GARZOLI

https://doi.org/10.17660/ActaHortic.1989.257.3