DE20119459U1 - Component for securing legionella free circulation systems - Google Patents

Description

Description

Component for securing

legionella-free

Circulation systems

Dipl. Ing. Karla Nestke
Dipl. Ing. Heinz Trabitz
Dipl. Ing. Gerhard Däumichen
Dipl. Ing. Knut Wehr

1. State of the art

The preparation of domestic hot water in district heating stations and boiler systems is carried out in accordance with the state of the art in flow systems in such a way that the hot water temperature is regulated by motor control valves or by valve combinations of motor valves with thermostatic safety temperature monitors and differential pressure overflow regulators controlled by an effective pressure sensor on the heating water side. When using valve combinations as described above, the circulation is kept at temperature via a bypass with a fixed aperture or via a pre-setting of the spring of the differential pressure overflow regulator. Different return temperatures, particularly during the heating period when the outside air temperature is relatively high, lead to fluctuating circulation temperatures due to the constant flow heating water quantity, which can also fall below the values required to prevent legionella. It is also necessary that the return temperature of the heating system is limited so that the hot water temperature is maintained in accordance with the regulations under all conditions. This causes problems in particular with one-pipe heating systems, so that such systems are mainly used with two-pipe heating systems.

2. Task to be solved

The aim of the utility model is to remedy the deficiencies of the state of the art and to find a technical solution that achieves a circulation water temperature in the legionella-free range with low temperature fluctuations and safe compliance with the permissible maximum value for hot water preparation in the flow system, regardless of the circulation water quantity and the heating water conditions.

3. Design of the utility model and achievable technical results

Based on the aim of the invention, a component was developed which, by being arranged between the flow rail and the return rail (according to Appendix 1 and 2), always achieves a control of the circulating water temperature with simultaneous limitation of the maximum value under all conditions and switching states. The component consists of a differential pressure generator, active in the form of a pump (11) or passive through a motor control valve (15), a temperature control valve with type-tested temperature controller (9, 14), a plate heat exchanger (8), a check valve (10) and a throttle cone valve or a volume flow controller (12) for adapting the return water partial flow to the pressure conditions. The temperature control valve (9, 14) mixes the return volume flow pumped by the pump (11) (Appendix 1) or by the differential pressure via the motor valve (15) (Appendix 2) with the supply water in the amount required to achieve a circulation temperature between 55 and 60 ⁰ C at a max. wall temperature of 60 ⁰ C in the plate heat exchanger.

The hot water flow system (1 to 6) works independently of the circulation, which is operated exclusively via the components of the system l and 2. The arrangement of the component in the entire flow system can be used universally, even if the drinking water is very hard. If the drinking water is less hard, the addition of return water is not necessary. Item (10), the lines from items (10) and (11) to the return and items (11) and (12) are then omitted. In a two-stage design of the flow system, the component can be combined with the plate heat exchanger (after-heater). The temperature control valve is equipped with a type-tested temperature controller in accordance with DIN 4747.

4. Applicability

The utility model can be used as a component in the construction of direct and indirect hot water stations and boiler systems and for retrofitting existing systems.

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L ist of references

1 control valve

2 differential pressure overflow regulators

3 Differential pressure sensors

4 Plate heat exchangers of the flow system

5 sensor safety temperature monitor

6 : Sensor temperature controller

7 Differential pressure regulator

8 plate heat exchangers for circulation

9 Temperature control valve

10 Check valve

11 Pump

12 Throttle cone valve / volume flow regulator

13 Circulation pump

14 Sensor temperature controller

15 Motor control valve of the heat exchanger station

Claims (2)

1. Component for safeguarding legionella-free circulation systems in hot water preparation systems with a flow system, characterized in that a component consisting of a differential pressure generator on the return side, a type-tested temperature control valve ( 9 , 14 ), a plate heat exchanger ( 8 ), a check valve ( 10 ) and a volume flow controller ( 12 ) is arranged parallel to the actual flow system. 2. Component for safeguarding legionella-free circulation systems according to claim 1, characterized in that the differential pressure generator can be used actively as a pump or passively as a motor control valve.