Search

EP-4741718-A1 - EFFICIENT FRESH WATER STATION

EP4741718A1EP 4741718 A1EP4741718 A1EP 4741718A1EP-4741718-A1

Abstract

A fresh water station (1) for providing hot drinking water, in particular for an apartment, comprises a heat exchanger (2). The heat exchanger (2) has a drinking water inlet (3) and a drinking water outlet (4). The heat exchanger (2) includes a flow inlet (5) and a return outlet (6) for a temperature control medium. The fresh water station (1) includes an electric instantaneous water heater (7), the instantaneous water heater (7) being arranged upstream of the flow inlet (5). The fresh water station (1) includes a connection (12) for a primary flow of the temperature control medium. The instantaneous water heater (7) is arranged downstream of the connection (12) for a primary flow of the temperature control medium.

Assignees

  • Roth Werke GmbH

Dates

Publication Date
20260513
Application Date
20251107

Claims (15)

  1. Fresh water station (1) for providing hot drinking water, in particular for an apartment, wherein the fresh water station (1) comprises a heat exchanger (2), wherein the heat exchanger (2) has a drinking water inlet (3) and a drinking water outlet (4), wherein the heat exchanger (2) comprises a flow inlet (5) and a return outlet (6) for a temperature control medium, wherein the fresh water station (1) comprises an electric instantaneous water heater (7), wherein the instantaneous water heater (7) is arranged upstream of the flow inlet (5), and wherein the fresh water station (1) comprises a connection (12) for a primary flow of the temperature control medium. characterized by the fact that the flow heater (7) is arranged downstream of the connection (12) for a primary supply of the temperature control medium.
  2. Fresh water station (1) according to claim 1, wherein the instantaneous water heater (7) is arranged directly upstream of the supply inlet (5), so that preferably there is no fluidic branch between the instantaneous water heater (7) and the supply inlet (5).
  3. Fresh water station (1) according to claim 1 or 2, wherein a branch (22) for the primary supply is arranged downstream of the connection (12) for the primary supply, wherein the branch (22) is preferably located upstream of the supply inlet (5) or the instantaneous water heater (7).
  4. Fresh water station (1) according to one of claims 1 to 3, wherein the fresh water station (1) has a sensor (19) for the instantaneous water heater (7), wherein the sensor (19) preferably detects a volume flow of a temperature control medium flowing through the instantaneous water heater (7).
  5. Fresh water station (1) according to one of claims 1 to 4, wherein the fresh water station (1) comprises a valve (16) for a primary return, wherein the valve (16) for the primary return preferably controls a volume flow of the temperature control medium through the instantaneous water heater (7).
  6. Fresh water station (1) according to one of claims 1 to 5, wherein the fresh water station (1) has a temperature sensor (34) for the hot water, wherein the temperature sensor (34) is preferably arranged at the drinking water outlet (4) or downstream of the drinking water outlet (4).
  7. Fresh water station (1) according to one of claims 1 to 6, wherein the instantaneous water heater (7) or the fresh water station (1) is designed such that the instantaneous water heater (7) allows a temperature rise of the temperature control medium of at most 30 or 25 or 20K.
  8. Fresh water station (1) according to one of claims 1 to 7, wherein the electrical rated power of the instantaneous water heater (7) amounts to at least 4 or 6 or 8 or 10 kW.
  9. Fresh water station (1) according to one of claims 1 to 8, wherein the instantaneous water heater (7) comprises connections for three phases of a three-phase current, wherein it is preferred that the instantaneous water heater (7) has at least one thyristor or a thyristor circuit.
  10. Fresh water station (1) according to one of claims 1 to 9, wherein the instantaneous water heater (7) has at least 2 or 3 or 4 or 7 or 10 or 13 power levels.
  11. Fresh water station (1) according to one of claims 1 to 10, wherein the instantaneous water heater (7) comprises at least one electric heating element and further preferably three electric heating elements, wherein the instantaneous water heater (7) is preferably designed such that the temperature control medium comes into contact with the at least one electric heating element or flows around the at least one electric heating element.
  12. Fresh water station (1) according to one of claims 1 to 11, wherein the fresh water station (1) has a rear wall, wherein it is preferred that the heat exchanger (2) and/or the instantaneous water heater (7) is/are attached indirectly or directly to the rear wall or to a front of the rear wall.
  13. Fresh water station (1) according to one of claims 1 to 12, wherein the fresh water station (1) comprises a connection (13) for a secondary supply of the temperature control medium and/or a connection (14) for a secondary return of the temperature control medium.
  14. Fresh water station (1) according to one of claims 1 to 13, wherein the fresh water station (1) comprises three drinking water connections (8, 9, 10), preferably a drinking water inlet connection (9), a hot water connection (8) and/or a cold water connection (10).
  15. Use of a fresh water station (1) according to one of claims 1 to 14 in fluidic connection with a primary circuit and/or with a low-temperature supply, preferably with a low-temperature supply of a primary circuit, wherein the primary circuit or the low-temperature supply is preferably provided by a low-temperature heat generator, for example by a heat pump, wherein the fresh water station (1) or apartment station is preferably fluidically connected to a secondary circuit and in particular to a surface heating element.

Description

The invention relates to a fresh water station for providing hot drinking water (domestic hot water) to an apartment, wherein the fresh water station comprises a heat exchanger, the heat exchanger having a drinking water inlet and a drinking water outlet, the heat exchanger comprising a flow inlet and a return outlet for a temperature control medium, the fresh water station comprising an electric instantaneous water heater, the instantaneous water heater being arranged upstream of the flow inlet, and the fresh water station comprising a connection for a primary flow of the temperature control medium. The invention further relates to the use of the fresh water station in conjunction with a heat pump. Fresh water stations of this type are well-established in practice and are increasingly being connected to heating systems with heat pumps. The heat pumps supply a primary flow temperature of a temperature-control medium, for example, 40°C, which is mixed to a secondary flow temperature of, for example, 30°C for underfloor heating. This mixing takes place in the fresh water station, where a return flow from the secondary circuit is mixed with the flow from the primary circuit in a mixing valve – according to the underfloor heating requirements. The water from the secondary circuit then leaves the fresh water station via a secondary flow connection, heading towards the underfloor heating system. The water from the primary supply line, in the state of the art, is also used in the heat exchanger for heating the drinking water (domestic hot water preparation). In the heat exchanger, the cold drinking water (cold water) is heated in a counterflow process by the warm temperature control medium from the primary circuit, with fluidic separation of these two circuits. However, the supply temperature of the primary circuit of 40°C is insufficient. It is not possible to heat the drinking water to a target temperature of, for example, 50°C. For this reason, an instantaneous water heater is integrated into the fresh water station on the drinking water side of the heat exchanger and downstream of the heat exchanger. The approximately 50°C hot water then leaves the fresh water station via a hot water connection to a tap in the apartment. The tap will typically have a mixing valve to mix the hot water with the cold water. A disadvantage, however, is that the heat exchanger operates with a flow temperature of 40°C, which is often set by heat pumps and is also the optimal temperature for Legionella bacteria to multiply. If the drinking water remains in the heat exchanger for a while, it cools down only slowly. Thus, Legionella bacteria find ideal temperatures between 40°C and 25°C for a period of time. A freshwater station mentioned earlier is also located in EP 2 469 193 B1 The instantaneous water heater is located in the flow line of the primary circuit and downstream of the boiler, as described in variant 2. Downstream of the instantaneous water heater and within the fresh water station, the flow line splits at a branch, with the first branch leading into the counterflow heat exchanger. A second branch leads via a mixing valve (secondary circuit return + primary circuit flow) to a pump in the secondary flow. The secondary flow may, for example, supply underfloor heating. In this way, the additional heat supplied by the instantaneous water heater is used for both the secondary circuit/underfloor heating and for domestic hot water preparation. A disadvantage of the prior art according to... EP 2 469 193 B1 is that the electricity consumption of such a The system's energy consumption is relatively high and should therefore be reduced. The invention is therefore based on the objective of creating a particularly energy-efficient fresh water station. This problem is solved by a fresh water station for providing hot drinking water, in particular for an apartment, wherein the fresh water station comprises a heat exchanger, wherein the heat exchanger has a drinking water inlet and a drinking water outlet, wherein the heat exchanger comprises a flow inlet and a return outlet for a temperature control medium, wherein the fresh water station comprises an electric instantaneous water heater, wherein the instantaneous water heater is arranged upstream of the flow inlet, and wherein the fresh water station comprises a connection for a primary flow of the temperature control medium. characterized by the fact that The instantaneous water heater is located downstream of the connection for a primary supply of the temperature control medium. The invention is based on the initial finding that an electric instantaneous water heater has an efficiency of nearly 1, meaning that 1W of electrical power is converted into nearly 1W of heat output. The invention is further based on the finding that, depending on the heat pump type and under certain defined heat source conditions, heat pumps can typically provide between 2.5W (air source heat pump) and 5W