Functional Principle Of Domestic Water Heater; Functional Description Of Electronic Control - WATERKOTTE F41449 Planification Et Installation

Functional principle of domestic water heater

2 Functional principle of domestic water heater

2.1 Functional description of electronic control

24.10.2018
The domestic water heater is used for the hygienic heating of domestic
water. Hot water from the heat pump heats up the domestic water drawn
from the tap by means of a heat pump. The integrated electronic control
defines the drawing temperature during the draw-off process. Use of the
domestic water heater in your home requires:
 a heat pump or thermal solar system
 a domestic hot water tank (loading tank)
The control manages the circulation pump on primary side in such a way as
to ensure lowest possible heating return temperature by means of hot water
draw-off volume and available heating flow temperature. In the course of
this, the hot water temperature always corresponds to the set point on the
controller. If the tank becomes too cold, i.e. if the temperature level on the
heating side is too low, and the "target domestic hot water temperature" is
no longer attainable, the set point will be adjusted. This means that the tar-
get value for the domestic water is adjusted downward until the domestic
hot water temperature is reached again. This is called "sliding set point".
The hydraulic scheme with the required control sensor is shown in Figure 1.
Figure 1: Electronic compact domestic water heater
1 Plate heat exchanger
2 Tank discharge pump
3 Quick vent valve
TIC 1 Temperature sensor
FTIC 2 Flow rate / temperature sensor
A Primary side
B Secondary side
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