Gas Regulating Unit, Gas Regulating Valve And System With Such A Gas Regulating Valve For Fail-Safe Pressure Regulation In A Gas Heater

Abstract

A gas regulating unit (10) for fail-safe regulation of a gas, specifically in a gas heater (1) or a gas burner, has a communication interface (15), a first sensor assembly (11), and a second sensor assembly (12). The first sensor assembly (11) is configured to acquire measured values from which a signed first differential pressure (p11) between a process pressure (p1) of the gas and a reference pressure (p0) is determinable. The second sensor assembly (12) is configured to acquire measured values from which a signed second differential pressure (p12) between the reference pressure (p0) and the process pressure (p1) is determinable. Thus, the signed first differential pressure (p11) and the signed second differential pressure (p12) are signed mutually inverse differential pressures (p11, p12). The communication interface (15) is configured to send the mutually inverse differential pressures (p11, p12) and/or the measured values to an external receiver.

What is claimed is: 
     
         1 . A gas regulating unit for fail-safe regulation of a gas, specifically in a gas heater or a gas burner, comprising:
 a communication interface, a first sensor assembly, and a second sensor assembly;   the first sensor assembly is configured to acquire measured values from which a signed first differential pressure (p 11 ) between a process pressure (p 1 ) of the gas and a reference pressure (p 0 ) is determinable;   the second sensor assembly is configured to acquire measured values from which a signed second differential pressure (p 12 ) between the reference pressure (p 0 ) and the process pressure (p 1 ) is determinable, so that the signed first differential pressure (p 11 ) and the signed second differential pressure (p 12 ) are signed mutually inverse differential pressures (p 11 , p 12 ); and   the communication interface is configured to send the mutually inverse differential pressures (p 11 , p 12 ) and/or the measured values to an external receiver.   
     
     
         2 . The gas regulating unit according to  claim 1 , wherein the first sensor assembly is a first differential pressure sensor or is a first mass flow sensor or has at least two sensors, each configured as a pressure sensor or as a mass flow sensor, and/or
 wherein the second sensor assembly is a second differential pressure sensor or is a second mass flow sensor or has at least two sensors, each configured as a pressure sensor or as a mass flow sensor.   
     
     
         3 . The gas regulating unit according to  claim 1 , wherein the first sensor assembly is a first differential pressure sensor and the second sensor assembly is a second differential pressure sensor;
 the differential pressure sensors each have a first pressure input and a second pressure input and are configured to ascertain a differential pressure (p 11 , p 12 ) by subtracting a pressure applied to the second pressure input from a pressure applied to the first pressure input;   the process pressure (p 1 ) is applied to the first pressure input of the first differential pressure sensor, and the reference pressure (p 0 ) is applied to the second pressure input of the first differential pressure sensor;   the reference pressure (p 0 ) is applied to the first pressure input of the second differential pressure sensor, and the process pressure (p 1 ) is applied to the second pressure input of the second differential pressure sensor, so that the differential pressures (p 11 , p 12 ) ascertained by the two differential pressure sensors ( 11 ,  12 ) are mutually inverse.   
     
     
         4 . The gas regulating unit according to  claim 1  further comprising:
 control electronics signalling connected to the first sensor assembly and the second sensor assembly and configured to acquire the mutually inverse differential pressures (p 11 , p 12 ) or determine them from the measured values. 
 
     
     
         5 . The gas regulating unit according to  claim 4  further comprising:
 an actuator interface for triggering an actuator, specifically a stepper motor, signalling connected to the control electronics or formed integrally with the control electronics. 
 
     
     
         6 . The gas regulating unit according to  claim 4 , wherein the communication interface is signalling connected to the control electronics or is formed integrally with the control electronics,
 the communication interface is specifically configured to receive control signals.   
     
     
         7 . A gas regulating valve for fail-safe regulation of a gas in a gas heater or a gas burner comprising:
 a gas regulating unit according to  claim 1  and a final control element for adjusting passage of a gas flowing from an inflow side to an outflow side of the gas regulating valve; and   the process pressure (p 1 ) is the pressure of the gas on the outflow side of the gas regulating valve.   
     
     
         8 . The gas regulating valve according to  claim 7 , wherein the reference pressure (p 0 ) is an ambient pressure at the gas regulating unit and/or the gas regulating valve. 
     
     
         9 . The gas regulating valve according to  claim 7  further comprising:
 an actuator signalling connected to the actuator interface of the gas regulating unit and configured to adjust the final control element for adjusting the passage. 
 
     
     
         10 . The gas regulating valve according to  claim 9 , wherein the control electronics are configured to adjust the final control element for adjusting the passage by triggering the actuator until at least one of the differential pressures (p 11 , p 12 ) and/or measured values corresponds to a predetermined value and/or is 0 Pa. 
     
     
         11 . A system for fail-safe regulation of a gas in a gas heater or a gas burner comprising:
 a control unit for regulating combustion and a gas regulating valve according to  claim 7 ;   the control unit is signalling connected to the communication interface of the gas regulating unit as an external receiver and is configured to receive and process the mutually inverse differential pressures (p 11 , p 12 ) and/or to send control signals to the communication interface.   
     
     
         12 . The system according to  claim 11 , wherein the control unit is configured to
 plausibility check the mutually inverse differential pressures (p 11 , p 12 ) by comparing the mutually inverse differential pressures (p 11 , p 12 ) with target values or threshold values stored in the control unit,   and/or plausibility check the mutually inverse differential pressures (p 11 , p 12 ) by comparing the absolute values of the mutually inverse differential pressures (p 11 , p 12 ) with one another,   and/or plausibility check the application of the process pressure (p 1 ) and the reference pressure (p 0 ) to the sensor assemblies ( 11 ,  12 ).   
     
     
         13 . A method for plausibility checking differential pressures (p 11 , p 12 ) acquired with a system for fail-safe pressure regulation according to  claim 11  comprising:
 triggering the final control element of the gas regulating valve or a safety valve, provided upstream of the gas regulating valve, to change the process pressure (p 1 ), so that the change in the process pressure (p 1 ) changes the first differential pressure (p 11 ) and the second differential pressure (p 12 ) inversely to one another; 
 comparing, after their change, the mutually inverse differential pressures (p 11 , p 12 ) with a respective target value or threshold value, and by means of the comparison; 
 checking whether the first differential pressure (p 11 ) associated with the first sensor assembly is the differential pressure acquired from the first sensor assembly, and/or whether the second differential pressure (p 12 ) associated with the second sensor assembly is the differential pressure acquired from the second sensor assembly, and/or whether the process pressure (p 1 ) is applied to the first sensor assembly as intended, and/or whether the reference pressure (p 0 ) is applied to the first sensor assembly as intended, and/or whether the reference pressure (p 0 ) is applied to the second sensor assembly as intended, and/or whether the process pressure (p 1 ) is applied to the second sensor assembly as intended. 
 
     
     
         14 . The method according to  claim 13 , wherein a fault is detected and output if the mutually inverse differential pressures (p 11 , p 12 ) do not correspond to the respective target values or do not reach the respective threshold values.