Apparatus for determining enthalpy of a fluid medium
AssigneeBabcock-BSH GmbH
InventorsFriedrich Bahner, Harry Pleva
Life of this patent
Estimating the term…
Abstract
Enthalpy quantities such as the degree of moisture of gases, the wetness of steam or the enthalpy of dry steam are measured by passing a specific amount or dosage of a gas or steam through a system such as a cooler or dryer wherein its thermal condition is changed while measuring the inlet and outlet temperature, and measuring heat radiated into the condition changing system whereupon the desired enthalpy quantity is obtained from a heat balance equation set up from the measured and known data.
Claims9
An apparatus for determining quantities of enthalpy of a fluid medium, comprising tubular duct means through which the medium is passed;
- means for measuring mass flow of the passing medium;
- a system for altering thermal condition of the passing medium so as to cause the medium to release or absorb heat;
- means for measuring inlet and outlet temperatures of the passing medium;
- heat flow measuring means installed between said duct means and said thermal condition altering system, said heat flow measuring means including two concentric electrically insulated wire coils of a material having temperature dependent resistance, said coils being disposed around said duct means in spaced and concentric relationship to each other, and further including a layer of a material of a moderate thermal conductivity and having a predetermined thickness, said layer being interposed between the two wire coils to form a thermal resistance, and said coils arranged at opposite sides of the thermal resistance to determine the heat flow as a function of temperature difference across said resistance;
- whereby the quantities of enthalpy are computed from a heat balance equation which is set up from the measured data of mass flow, heat flow and the inlet and outlet temperatures.
An apparatus for determining wetness of a steam medium, comprising tubular duct means through which the steam medium is passed from a steam chamber;
- means for controlling mass flow of the passing medium;
- a heating device associated in said duct means for altering a thermal condition of the passing medium;
- means for measuring inlet and outlet temperatures of the passing medium;
- heat flow measuring means being installed around said duct means, said heat flow measuring means including two concentric electrically insulated wire coils of a material having temperature dependent resistance, said coils being disposed around said duct means in spaced and concentric relationship to each other, and further including a layer of a material of a moderate thermal conductivity and having a predetermined thickness, said layer being interposed between the two wire coils to form a thermal resistance, said coils arranged at opposite sides of the thermal resistance to determine the heat flow as a function of temperature difference across said resistance;
- and a chamber for receiving steam discharged through said duct means whereby the quantities of enthalpy are computed from a heat balance equation which is set up from the measured data of mass flow, heat flow and the inlet and outlet temperatures in said steam and receiving chambers, respectively.
An apparatus for determining quantities of enthalpy of a dry steam medium, comprising tubular duct means connected to a steam chamber through which the medium is passed;
- dosing means in said duct means to control the amount of the steam medium passing out of said chamber;
- cooling means for altering a thermal condition of the passing medium;
- at least one means for measuring temperatures of the passing medium;
- heat flow measuring means installed between said duct means and said cooling means;
- said heat flow measuring means including two concentric electrically insulated wire coils of a material having temperature dependent resistance, said coils being disposed around said duct means in spaced and concentric relationship to each other, and further including a layer of a material of a moderate thermal conductivity and having a predetermined thickness, said layer being interposed between the two wire coils to form a thermal resistance, said coils arranged at opposite sides of the thermal resistance to determine the heat flow as a function of temperature difference across said resistance;
- and collecting means arranged at the outlet of said duct means;
- whereby the quantities of enthalpy are computed from a heat balance equation which is set up from the measured data of mass flow, heat flow and temperature.
Dependencies are inferred from the claim text.