| 摘要 |
A liquid flow through heater for heating a liquid (10) comprises a channel (4) and an electric heater element (50) for heating at least a portion of the channel (4). A temperature sense unit (6, 60) senses a temperature (ST1; ST1, ST2) indicative of the temperature of the liquid. A flow control means (3) controls a flow of the liquid (10) through the channel (4). A controller (7) controls in a first phase (PH1), (i) the electric heater element (50) to pre-heat at least the portion of the channel (4), and (ii) the flow control means (3) to obtain a rate of flow of the liquid (10) through the channel (4) which is zero or relatively small with respect to a rate of flow during a second and/or third phase. The controller (7) controls in the second phase (PH2) succeeding the first phase (PH1), (i) the electric heater element (50) to supply a predetermined heating power independent on the sensed temperature (ST1; ST1, ST2), and (ii) the flow control means (3) to obtain a flow of the liquid (10) through the channel (4), and in the third phase (PH3) succeeding the second phase (PH2), (i) the electric heater element (50) to supply a heating power (HP) in dependence on the sensed temperature (ST1; ST1, ST2) to substantially stabilize the sensed temperature (ST1; ST1, ST2) on a desired target value (TV), and (ii) the flow control means (3) to obtain a flow of the liquid (10) through the channel (4).
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