Enthalpy calculating device for steam

Claim 2

An enthalpy-calculating device for calculating the enthalpy of steam including a function generator for receiving a first input signal corresponding to the magnitude of the temperature of the steam and a second input signal corresponding to the magnitude of the enthalpy of the steam, and for emitting an output signal corresponding to the determined magnitude of the pressure of the steam in response to said input signals; a first input terminal for receiving said first input signal for emission to said function generator; a second input terminal for receiving an output signal corresponding to the magnitude of the pressure of the monitored steam; and a controller means connected to said second input terminal to receive said input signal therefrom and to said function generator to receive the emitter output signal thereof for comparing said respective signals, said controller means having an output terminal for emitting said second input signal in response to a comparison of said respective signals to said function generator and to an output terminal of said device.

Claim 3

A device as set forth in claim 1 in which said function generator is arranged to generate a function of the form: z a00 + a01x + a02x2 + a03x3 . . . + a0mxm + (a10 + a11x + a12x2 . . . + a1mxm) . Y + (a20 + a21x + . . . + a2mxm) . Y2 . . + (an0 + an1x + an2x2 . . . + anmxm) . Yn, where y and x are said first and second input signals and z is said output signal.

Claim 4

A device as set forth in claim 1 in combination with a forced through-flow steam generator, said first and second input terminals being connected respectively to temperature and pressure sensors arranged to measure the temperature and pressure of steam at a point in said steam generator, and said output terminal of said device being operatively connected to a means in said generator for adjusting a supply of feed water to said steam generator.

Claim 5

The combination as set forth in claim 3 wherein said point is in the zone of incipient superheating in said steam generator.

Claim 6

An enthalpy calculating device for calculating the enthalpy of steam including a first input terminal for receiving a first input signal corresponding to the magnitude of the temperature of a monitored flow of steam; a second input terminal for receiving a second input signal corresponding to the magnitude of the pressure of the flow of steam; a function generator having a pair of input terminals for receiving signals corresponding to the magnitude of the enthalpy and the temperature of the monitored flow of steam and an output terminal for emitting a signal corresponding to the magnitude of the pressure of the monitored flow of steam; a controller means having a pair of input terminals for receiving signals corresponding to the output of said function generator and the magnitude of the pressure of the flow of steam and an output terminal for emitting an output signal corresponding to the enthalpy of the monitored flow of steam; said function generator having one of said input terminals thereof connected to said first input terminal to receive said first input signal, the other of said input terminals thereof connected to said output terminal of said controller means to receive said output signal thereof, and said output terminal thereof connected to an input terminal of said controller means to emit said signal corresponding to the determined magnitude of the pressure of the monitored flow of steam thereto; said controller means having the other of said input terminals thereof connected to said second input of said device to receive said second input signal and having said output terminal thereof connected to said output terminal of said device to emit said output signal thereto.

Claim 7

An enthalpy calculating device for calculating the enthalpy of steam including a first input terminal for receiving a first input signal corresponding to the magnitude of the temperature of a monitored flow of steam; a second input terminal for receiving a second input signal corresponding to the magnitude of the pressure of the flow of steam; a function generator having a pair of input terminals for receiving signals corresponding to the magnitude of the enthalpy and the temperature of the monitored flow of steam and an output terminal for emitting a signal corresponding to the magnitude of the pressure of the monitored flow of steam; a controller means having a pair of input terminals for receiving signals corresponding to the output of said function generator and the magnitude of the pressure of the flow of steam and an output terminal for emitting an output signal corresponding to the enthalpy of the monitored flow of steam; said function generator having one of said input terminals thereof connected to said first input terminal to receive said first input signal, the other of said input terminals thereof connected to said output terminal of said controller means to receive said output signal thereof, and said output terminal thereof connected to an input terminal of said controller means to emit said signal corresponding to the determined magnitude of the pressure of the monitored flow of steam thereto; said controller means having the other of said input terminals thereof connected to said second input of said device to receive said second input signal and having said output terminal thereof connected to said output terminal of said device to emit said output signal thereto.

Claim 8

A device as set forth in claim 5 wherein said controller means includes a comparator and an integrator, said comparator being connected to said output terminal of said function generator to receive said output signal corresponding to the enthalpy and to said second input terminal to receive said second input signal for comparison with said output signal, said integrator being connected to said comparator to receive a difference signal for integration in response to a deviation of said output signal of said function generator from said second input signal, said integrator being connected to said second input of said function generator.

Claim 9

A device as set forth in claim 5 wherein said controller means is an integral action controller.

Claim 10

A device as set forth in claim 5 in which said function generator generates a function of the form: z a00 + a01x + a02x2 + a03x3 . . . + a0mxm + (a10 + a11x + a12x2 . . . + a1mxm) . Y + (a20 + a21x + . . . + a2mxm) . Y2 . . + (an0 + an1x + an2x2 . . . + anmxm) . Yn, where y and x are said first and second input signals and z is said otput signal.

Claim 11

An enthalpy-calculating device for calculating the enthalpy of steam including a function generator for receiving a first input signal corresponding to the magnitude of the pressure of the steam and a second input signal corresponding to the magnitude of the enthalpy of the steam, and for emitting an output signal corresponding to the determined magnitude of the temperature of the steam in response to said input signals; a first input terminal for receiving said first input signal for emission to said function generator; a second input terminal for receiving an input signal corresponding to the magnitude of the temperature of the monitored steam; and a controller means connected to said second input terminal to receive said input signal therefrom and to saiD function generator to receive the emitted output signal thereof for comparing said respective signals, said controller means having an output termeinal for emitting said second input signal in response to a comparison of said respective signals to said function generator and to an output terminal of said device.

Claim 12

An enthalpy-calculating device for calculating the enthalpy of steam including a function generator for receiving a first input signal corresponding to the magnitude of the pressure of the steam and a second input signal corresponding to the magnitude of the enthalpy of the steam, and for emitting an output signal corresponding to the determined magnitude of the temperature of the steam in response to said input signals; a first input terminal for receiving said first input signal for emission to said function generator; a second input terminal for receiving an input signal corresponding to the magnitude of the temperature of the monitored steam; and a controller means connected to said second input terminal to receive said input signal therefrom and to saiD function generator to receive the emitted output signal thereof for comparing said respective signals, said controller means having an output termeinal for emitting said second input signal in response to a comparison of said respective signals to said function generator and to an output terminal of said device.

Claim 13

A device as set forth in claim 9 in which said function generator is arranged to generate a function of the form: z a00 + a01x + a02x2 + a03x3 . . . + a0mxm + (a10 + a11x + a12x2 . . . + a1mxm) . Y . . + (an0 + an1x + an2x2 . . . + anmxm) . Yn, where y and x are said first and second input signals and z is said output signal.

Claim 14

A device as set forth in claim 9 in combination with a forced through-flow steam generator, said first and second input terminals being connected respectively to temperature and pressure sensors arranged to measure the temperature and pressure of steam at a point in said steam generator, and said output terminal of said device being operatively connected to a means in said generator for adjusting a supply of feed water to said steam generator.

Claim 15

The combination as set forth in claim 11 wherein said point is in the zone of incipient superheating in said steam generator.

Claim 16

An enthalpy-calculating device for calculating the enthalpy of steam including a first input terminal for receiving a first input signal corresponding to the magnitude of the pressure of a monitored flow of steam; a second input terminal for receiving a second input signal corresponding to the magnitude of the temperature of the flow of steam; an output terminal for emitting an output signal corresponding to the enthalpy of the monitored flow of steam; a function generator having a pair of input terminals for receiving signals corresponding to the magnitude of the enthalpy and the pressure of the monitored flow of steam and an output terminal for emitting a signal corresponding to the magnitude of the temperature of the monitored flow of steam; a controller means having a pair of input terminals for receiving signals corresponding to the measured output of said function generator and the magnitude of the temperature of the flow of steam and an output terminal for emitting an output signal corresponding to the measured enthalpy of the monitored flow of steam; said function generator having one of said input terminals thereof connected to said first input terminal to receive said first input signal, the other of said input terminals thereof connected to said output terminal of said controller means to receive said output signal thereof, and said output terminal thereof connected to an input terminal of said controller means to emit said signal corresponding to the determined magnitude of the temperature of the monitored flow of steam thereto; said controller means having the other of said input terminals thereof connected to said second input of said device to receive said second input signal and having said output terminal thereof connected to said output terminal of said device to emit said output signal thereto.

Claim 17

An enthalpy-calculating device for calculating the enthalpy of steam including a first input terminal for receiving a first input signal corresponding to the magnitude of the pressure of a monitored flow of steam; a second input terminal for receiving a second input signal corresponding to the magnitude of the temperature of the flow of steam; an output terminal for emitting an output signal corresponding to the enthalpy of the monitored flow of steam; a function generator having a pair of input terminals for receiving signals corresponding to the magnitude of the enthalpy and the pressure of the monitored flow of steam and an output terminal for emitting a signal corresponding to the magnitude of the temperature of the monitored flow of steam; a controller means having a pair of input terminals for receiving signals corresponding to the measured output of said function generator and the magnitude of the temperature of the flow of steam and an output terminal for emitting an output signal corresponding to the measured enthalpy of the monitored flow of steam; said function generator having one of said input terminals thereof connected to said first input terminal to receive said first input signal, the other of said input terminals thereof connected to said output terminal of said controller means to receive said output signal thereof, and said output terminal thereof connected to an input terminal of said controller means to emit said signal corresponding to the determined magnitude of the temperature of the monitored flow of steam thereto; said controller means having the other of said input terminals thereof connected to said second input of said device to receive said second input signal and having said output terminal thereof connected to said output terminal of said device to emit said output signal thereto.

Claim 18

A device as set forth in claim 13 wherein said controller means includes a comparator and an integrator, said comparator being connected to said output terminal of said function generator to receive said output signal corresponding to the enthalpy and to said second input terminal to receive said second input signal for comparison with said output signal, said integrator being connected to said comparator to receive a difference signal for integration in response to a deviation of said output signal of said function generator from said second input signal, said integrator being connected to said second input of said function generator.

Claim 19

A device as set forth in claim 13 wherein said controller means is an integral action controller.

Claim 20

A device as set forth in claim 13 in which said function generator generatores a function of the form: z a00 + a01x + a02x2 + a03x3 . . . a0mxm + (a10 + a11x + a12x2 . . . + a1mxm) . Y + (a20 + a21x + . . . + a2mxm) . Y2 . . + (an0 + an1x + an2x2 . . . + anmxm) . Yn. where y and x are said first and second input signals and z is said output signal.