CALCULATING THE ENERGY REQUIREMENT
Main groups
- Frost protection/Heating of tanks, containers, screens, bunkers, cisterns etc.
The object is covered with heating cable, aluminium foil and thermal insulation to prevent freezing (heat losses through the thermal insulation).
Formula
Heat loss calculation
| Q = | A x k x Δt x s |
| S x E |
| Q | = | Heat loss through thermal insulation (W). |
| A | = | The total frozen area of the object area (m²) |
| k | = | The insulation k-value |
| Δt | = | The difference in temperature between the object and environment. |
| S | = | The thickness of the insulation (m) |
| E | = | Correcting factor normally 0.8. |
| s | = | Safety factor (0=indoor/1,5=quay berth) |
- Heating of tanks, containers, screens, cisterns etc.
The object is covered with heating cable, aluminium foil and thermal insulation, partly to compensate the heat loss through the insulation and to rise the temperature at the object.
The heating-up time depends on installed power according to formula.
When calculating considerations should be taken to heat losses through the thermal insulation since this can prolong the calculated heating-up time some.
Calculating the energy requirement for heating
P = Q + Ph
| Ph = | V x G x c x th |
| h |
| P | = | Required power (W) |
| Q | = | Heat loss through the insulation (W). |
| Ph | = | Required power to increase the temperature on the object to required temperature in hours (W). |
| V | = | The volume of the object dm³ (Litre) |
| G | = | The density of the content (Kg/dm³) |
| c | = | Heat permittivity (Wh/Kg°C) |
| th | = | Required temperature increase (°C) |
| h | = | Heating-up time. |