The invention relates to a device or fluid storage unit (10) as a stratified storage unit with a device for introducing a fluid (9) into or removing a fluid (9) from the fluid storage unit (10). In the fluid storage unit (10), the fluid (9) stored therein is stored at different levels depending on its density. The most common application for fluid storage units (10) as stratified storage units is in building heating technology, where heating
water storage tanks (10) are used as stratified storage tanks. A device according to the invention enables the introduction of heating water (9) at precisely the level within the heating
water storage tank (10) that corresponds to its temperature. Even very large flow rates do not disrupt the
thermal stratification within the heating
water storage tank (10), thereby significantly increasing the energy efficiency of the
heating system.The device according to the invention can react very quickly to changing temperatures of the heating water (9) being introduced or to changes in the temperature distribution in the heating
water storage tank (10) and adjust the inlet height using temperature sensors (11) and an
electronic control unit (12). For this purpose, inlet openings (5) are controlled at the appropriate height. A small
electric motor, controlled by the
electronic control unit (12), is sufficient for the necessary adjustment. If a device according to the invention is used to
discharge a fluid (9) from a fluid
storage tank (10) as a stratified
storage tank, fluid (9) with precisely the desired density can be selectively discharged from the appropriate height of the fluid
storage tank (10).In the case of a heating
water storage tank (10), heating water (9) can be drawn off at precisely the right temperature for heating, thus eliminating the need for the mixing of hot and cooler heating water that is typical in heating systems. If, however, very hot heating water (9) is required, for example, to heat domestic hot water using a
plate heat exchanger, the device according to the invention can be adjusted very quickly so that very hot heating water (9) is drawn from further down or from the very top of the heating
water storage tank (10). A device according to the invention thus significantly increases the energy efficiency of the
heating system, even when used to draw off heating water (9) from a heating water storage tank (10). Advantageous embodiments of the devices according to the invention also include throttling elements (15) to reduce the
inflow velocity.Preferably, devices according to the invention are used for both the inlet and outlet processes.