Tank Insulation and Heating

To reduce heat loss and operate the tank during the winter period, tank insulation and heating are used. The need for insulation or heating, the insulation thickness, and the heating power are determined solely by a thermal calculation.

Based on our practical experience, we can highlight the following:

• if the water in the tank is refreshed frequently (every two days part of it is drained and new water is added), then heating and insulation are not required;
• if the water is refreshed at least once every 7–10 days, the tank must be insulated to prevent the water from freezing;
• if the water is refreshed less often than once every 10 days and the tank is operated in winter, both insulation and water heating are required.

These are very averaged figures. The exact need for insulation and heating also depends on the region, the temperature of the incoming water, and the frequency of water renewal, and is determined only by a thermal calculation. Above-ground fire-protection tanks, in which the water is not refreshed, require both insulation and heating during the winter period.

To insulate the side surface of modular tanks, we use polystyrene foam. The roof of a modular tank is insulated with high-density extruded polystyrene foam, which withstands the pressure of the liquid column in the tank.

The liquid heating system in the tank consists of a heating element (TEN), temperature sensors, and a control system. When the sensor reads a drop to a critical temperature (usually +1 °C), the heating element switches on. Once the water is heated to a set temperature, the sensors trigger and the heating element switches off. The energy consumption of the heating elements is not high:

• the average heating element power for a 100–500 m³ tank (northern and central Ukraine) is 6–8 kW;
• in "mild" winters, with the tank insulated, the heating elements operate 15–25 calendar days per year;
• in southern regions, where the average winter temperature is around 0 °C, the heating elements operate for just a few days a year.