Gas valve and method of control

摘要

A stepper-motor gas valve control is disclosed that includes a main diaphragm in a chamber that controllably displaces a valve relative to an opening in response to changes in pressure, to adjust fuel flow through the valve. A servo-regulator diaphragm is provided to regulate flow to the main diaphragm, to thereby control the rate of fuel flow. A stepper motor is configured to move in a stepwise manner to displace the servo-regulator diaphragm, to control fluid flow to the main diaphragm. A controller mounted on the stepper-motor regulated gas valve control receives and converts an input control signal from a heating system to a reference value between 0 and 5 volts, and selects a corresponding motor step value. The control responsively moves the stepper-motor in a step wise manner to displace the servo-regulator diaphragm and thereby regulates the rate of fuel flow through the valve.

主权项

1. A gas valve unit comprising:
a solenoid coil that generates a magnetic field in response to an input signal to the solenoid coil; a valve member that is movable in response to the magnetic field for controllably displacing a valve element relative to a valve opening to adjust a gas flow rate therethrough, where the input signal to the solenoid coil controls the extent of movement of the valve member relative to the valve opening; a sensor that provides an output indicative of a gas pressure at an outlet of the gas valve unit; a setting device that provides an input for selection of at least one opening flow rate profile that is a function describing desired outlet pressure over a time sequence associated with a valve opening phase for establishing combustion, the opening flow rate profile configured for use in controlling the level of gas flow for initially establishing combustion in a heating apparatus; and a valve controller in communication with the sensor and the setting device, the valve controller being configured to control the input signal to the solenoid coil to control movement of the valve element for controlling the gas flow rate through the outlet, the valve controller being configured to control the input signal to the solenoid coil based in part on the sensor output, to control the valve element and thereby control the gas flow rate at the outlet to provide outlet pressure over time in accordance with the opening flow rate profile selected by the setting device.