Liquid level measurement device

Abstract

The invention (2) relates to a device (2) that is simply constructed and displays a high fail safeness for using heated thermoelements (HT) and unheated thermoelements (UHT) as transmitters for measuring a liquid in a liquid container, in particular in the reactor container (4) of a nuclear installation, makes an especially precise and reliable measurement of the level height (H) possible. In addition, the invention proposes a plurality of elongated measuring tubes (6), at a distance from one another, wherein each measuring tube (6) exhibits a number of thermoelements (HT, UHT) arranged such that they are distributed in a longitudinal direction, and wherein an unheated thermoelement (UHT), acting as a reference transmitter, is allocated to a thermoelement (HT), acting as a primary transmitter, arranged at a first measuring tube (6) and heated by a heating element (HE) and which is arranged at a measuring tube (6) that is different from the first measuring tube (6).

Description

technical field [0001] The invention relates to a device based on the use of heated and unheated thermocouples as signal generators for measuring the liquid level in liquid containers, in particular reactor containers of nuclear technology installations. Background technique [0002] In measuring devices or level probes, which are used in particular in nuclear power plants, the level of the liquid in a liquid container can be inferred from the thermal stress produced by a heated thermocouple. This is because they are less sensitive to radioactive radiation than measuring devices based on other measuring principles and can therefore operate reliably even in the event of a possible fault with increased radiation values. Measuring devices of this type are used in particular in reactor pressure vessels of pressurized water reactors in order to monitor there the level of cooling liquid flowing through the main circuit of the power plant above the fuel elements. [0003] The meas...

AI Technical Summary

Problems solved by technology

This can especially lead to inaccuracies and misinterpretations of the measurement results if (as often occurs in practice) there is a non-negligible temperature gradient at the height of the liquid surrounding the measuring device

In addition, in such an embodiment of the measuring device, the number of possible measuring positions and thus the height resolution of the fill level display is greatly limited by the geometric settings of the probe housing or measuring tube housing.

Furthermore, for a given height, only one measuring unit or thermal sensor can be implemented; no redundancy is provided

Finally, the device according to RU2153712C1 also has the disadvantage that all heated thermocouples are heated by a common heating wire with heating zones connected in series

If the heating wire is damaged and the current is interrupted, the entire measuring device fails

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