Patent Grant
8539978
The present disclosure relates to systems for control of a gas fired appliance having a gas valve, and more particularly relates to gas valves for control of gas flow to such an appliance.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Gas-fired heating units or furnaces that operate at two or more gas flow rates are generally referred to as multistage furnaces. Multistage furnaces are frequently selected by homeowners over single stage furnaces because they offer increased performance and comfort by varying the level of heating output as needed. In many multistage furnaces, a furnace control may be configured to request operation of a gas valve at a desired operating capacity level or gas flow rate. The operating capacity level requested by such furnace controls could be as low as 30 percent of full capacity gas flow operation. However, at low capacity gas flow rates, such gas valves are not capable of controllably maintaining the gas flow rate within a desired tolerance, and therefore are not utilized at such low capacity levels. Accordingly, a need still exists for an improved valve unit and associated control for present two stage heating systems.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
Various embodiments are provided of a valve unit for a heating or combustion apparatus. One embodiment of a valve unit includes a valve member that moves relative to a valve seat in response to a signal input to a coil, for varying a high-capacity gas flow rate through the valve unit. The valve unit includes a first opening port, a second opening port that is smaller than the first opening port, and a closure member. The closure member is movable between an open position, in which said high-capacity gas flow rate is communicated via the first and second opening ports to at least one outlet, and a closed position against the first opening port, in which a low-capacity gas flow rate is communicated via only the second opening port to the at least one outlet. The valve unit includes a solenoid for selectively moving the closure member between the open and closed positions, to respectively selectively establish a high-capacity gas flow rate or low capacity gas flow rate to at least one outlet.
According to another aspect of the present disclosure, various embodiments of a valve unit are provided that are configured to control the signal that is input to the coil to adjust the gas flow rate through the valve seat to a desired gas flow rate. In some embodiments, the coil is part of a stepper-motor that displaces the valve member based on an input voltage applied to the stepper-motor coil, where the valve member is configured to displace a diaphragm to vary the gas flow rate through the valve unit. In other embodiments, the coil is a solenoid coil that is configured to move the valve member to vary the high-capacity gas flow rate based on the magnetic field generated by the coil, where the magnetic field is dependent on the input voltage.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples provided in this summary are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
Various embodiments are provided of a valve unit for a heating or combustion apparatus. One embodiment of a valve unit includes a valve member that moves relative to a valve seat in response to a signal input to a coil, for varying a high-capacity gas flow rate through the valve unit. The valve unit includes a first opening port, a second opening port that is smaller than the first opening port, and a closure member. The closure member is movable between an open position, in which said high-capacity gas flow rate is communicated via the first and second opening ports to an outlet, and a closed position against the first opening port, in which a low-capacity gas flow rate is communicated via only the second opening port to the outlet. The valve unit includes a solenoid for selectively moving the closure member between the open position and closed position to selectively establish a high-capacity gas flow rate or low capacity gas flow rate, respectively, to the outlet.
According to another aspect of the present disclosure, various embodiments of a valve unit are provided that are configured to control the signal that is input to the coil to adjust the gas flow rate through the valve seat to a desired gas flow rate. In some embodiments, the coil is part of a stepper-motor that displaces the valve member based on an input voltage applied to the stepper-motor coil, where the valve member is configured to displace a diaphragm to vary the gas flow rate through the valve unit. In other embodiments, the coil is a solenoid coil that is configured to move the valve member to vary the high-capacity gas flow rate based on the magnetic field generated by the coil, where the magnetic field is dependent on the input voltage.
The various embodiments of a valve unit are connectable to and operable with a variable heating system controller for a furnace or heating unit, where the variable-heating system controller initiates operation of the heating unit based on input signals from a single-stage, two-stage or other type of thermostat. To better illustrate the operation of the valve unit embodiments, an example of a variable-heating system controller for a heating unit 50 (shown in
In response to a thermostat activation signal, the variable-heating system controller 20 signals a valve unit 100 to establish gas flow to a burner 58. The variable-heating system controller 20 may be a two-stage controller that is configured to signal the valve unit 100 to establish a low-stage gas flow rate for a predetermined time period, and to thereafter signal the valve unit 100 to establish a high-stage gas flow rate after expiration of the predetermined time period. This may be achieved by a first switching means 30 for switching a voltage source “V” to a relay device 32 that switches voltage to a first connection 132 on the valve unit 100 to establish a low stage gas flow rate, and a second switching means 36 for switching voltage to a relay device 38 that switches voltage to a second connection 134 on the valve unit 100 to establish a high stage full-capacity gas flow rate to the burner 58. Alternatively, the variable-heating system controller 20 may be configured to provide (via wire 34) a pulse-width-modulation or other equivalent signal to the valve unit 100, which indicates a desired operating capacity level. Accordingly, an exemplary variable-heating system controller 20 may be configured to respond to one or more thermostat activation signals by signaling a valve unit 100 to establish a high capacity gas flow rate, a low capacity gas flow rate, or one or more variable gas flow rates therebetween.
Referring to
Specifically, the exemplary valve unit 100 in
In the various valve unit embodiments of the present disclosure, the function of establishing a select high-capacity gas flow rate or low-capacity gas flow rate may be equivalent to establishing a corresponding select outlet pressure at the outlet 105 of the valve unit 100, as explained below. Specifically, to achieve a desired high-capacity or low-capacity gas flow rate at a downstream location of a burner 58 (as shown in
Accordingly, the various valve unit embodiments are configured to control an input to a coil 120 to move a valve member 122 to establish an outlet pressure at the outlet 105 that corresponds to a selected capacity level or gas flow rate. In the exemplary valve unit 100 in
However, when the coil 120 and valve member 122 are operated to adjust the opening area to establish and maintain very low gas flow rates (e.g., at a low outlet pressure of about 1.0 inch of water column or less), the regulation over such low gas flow rates is typically not within a desired tolerance range. To establish such a consistent low capacity gas flow rate, the present exemplary valve unit 100 further includes a first opening port 140, and a second opening port 142 (or bypass orifice). The first and second opening ports 140, 142 are disposed downstream of the valve seat (e.g., seats 102, 103). The valve unit 100 further includes a closure member 144 that is movable between an open position and a closed position relative to the first opening port 140. When the closure member 144 moves to an open position, a high-capacity gas flow rate (set by valve member 122) is communicated to an outlet 105. When the closure member 144 moves to a closed position against the first opening port 140, a low-capacity gas flow rate is communicated via only the second opening port 142 to the valve outlet 105. In the valve unit 100 shown in
The second opening port 142 (or bypass orifice) preferably has an opening area less than about 0.100 inches2 that is effective to provide a low gas flow rate at a low outlet pressure of about 1.0 inch of water column or less, and to maintain the desired gas flow rate within a tolerance of +/−0.15 inches of water column. More preferably, the second opening port 142 may have a flow adjustment member 150 that is adjustable for varying the opening area of the second opening port 142. The flow adjustment member 150 may comprise a screw or other threaded component that is suitable for impinging or restricting the opening area of the second opening port 142.
The valve unit 100 further includes a solenoid 148 for selectively moving the closure member 144 between the open position and closed position to selectively establish a high-capacity gas flow rate or low capacity gas flow rate, respectively, to the outlet 105. Accordingly, the valve unit 100 includes a coil 120 for adjusting a valve member 122 to vary a high capacity gas flow rate through a valve seat (e.g., seats 102, 103), and a solenoid for selectively communicating either the high capacity gas flow rate or the low capacity gas flow rate to the outlet 105. This function enables the valve unit 100 to provide a desired high capacity gas flow rate to a heating apparatus, as well as a consistent low capacity gas flow rate that is maintained within a desired tolerance range.
Referring to
In the particular embodiments shown in
Referring to
The stepper motor coil 120 accordingly provides control over the extent of opening area relative to the valve seat 102, to provide modulated gas flow operation. The stepper motor operated valve unit 100′ preferably includes a valve controller 130 that is configured to receive an input signal that is indicative of a desired operating capacity level or gas flow rate from the furnace system controller 20 (shown in
To accommodate low capacity gas flow rates, the valve unit 100′ further includes a first opening port 140, and a second opening port 142 that is smaller than the first opening port. The first opening port 140 and the second opening port 142 are disposed downstream of the valve seat 102. The valve unit 100 further includes a closure member 144. The closure member 144 is movable between an open position, in which a high-capacity gas flow rate is communicated via the first and second opening ports 140, 142 to an outlet 105, and a closed position against the first opening port 140, in which a low-capacity gas flow rate is communicated via only the second opening port 142 to the outlet 105. The second opening port 142 preferably has an opening area less than about 0.100 inches2 that is effective to provide a low gas flow rate at a low outlet pressure of about 1.0 inch of water column or less, and to maintain the desired gas flow rate within a tolerance of +/−0.15 inches of water column. More preferably, the second opening port 142 may have a flow adjustment member 150 that is adjustable for varying the opening area of the second opening port 142. The valve unit 100′ further includes a closure solenoid 148 for selectively moving the closure member 144 between the open position and closed position to selectively establish a high-capacity gas flow rate or low capacity gas flow rate, respectively, to the outlet 105. Accordingly, the valve unit 100′ includes a coil 120 for adjusting a valve member 122 to vary a high capacity gas flow rate through a valve seat 102, and a solenoid for selectively communicating either the high capacity gas flow rate or the low capacity gas flow rate to the outlet 105. This selectivity enables the valve unit 100′ to provide a desired high capacity gas flow rate to a heating apparatus, as well as a consistent low capacity gas flow rate that is maintained within a desired tolerance range.
In the above described embodiments, the valve unit 100 includes a valve member 122 that moves in response to a magnetic field generated by a coil 120 to vary a gas flow rate through the valve unit 100, where the coil 120 may be a component of a solenoid or a stepper-motor that causes the displacement of a valve member 122. The various embodiments of a valve unit 100 further include a valve controller 130 for controlling the input to the coil 120 to controllably vary the gas flow rate of the valve unit 100, as explained below.
Operation at High-Capacity Gas Flow Rates
Referring back to
Similarly, where valve unit 100 receives a pulse-width-modulated signal or the like that includes information indicative of an operating capacity level corresponding to an outlet pressure above 1 inch of water column, the valve controller 130 is configured to control input to the coil 120 to establish a high-capacity gas flow rate corresponding to the operating capacity level, and configured to actuate closure solenoid 148 to move closure member 144 to an open position such that the high-capacity gas flow is communicated via the first and second opening ports 140, 142 to the outlet 105.
Operation at Low-Capacity Gas Flow Rates
Where the valve unit 100 receives a pulse-width-modulated signal indicative of an operating capacity level corresponding to an outlet pressure below 1 inch of water column, the valve controller is configured to control input to the coil 120 and to deactivate closure solenoid 148 to move closure member 144 to a closed position against the first opening port 140, such that a low-capacity gas flow rate is communicated via only the second opening port 142 (or bypass orifice) to outlet 105. The opening area of the second opening port 142 is effective to establish a low-capacity gas flow rate that is maintained within a desired tolerance range.
Alternatively, when the valve unit 100 receives a low stage activation signal (e.g., a signal from a two-stage furnace controller received via connection 134), the valve controller 130 is configured to control input to the coil 120 and to deactivate closure solenoid 148 to move closure member 144 to a closed position against the first opening port 140. In this position, a low-capacity gas flow rate is communicated via the second opening port 142 to the outlet 105 as long as the low stage activation signal is present at the second connection 134.
Referring to
Accordingly, the above embodiments of a valve unit 100 including a valve controller 130 that is connectable to and operable with a furnace system controller 20 that may be two-stage controller or a variable capacity furnace controller. The valve unit 100 including a valve controller 130 is configured to control a closure solenoid 148 for selectively moving the closure member 144 between an open position, in which a high-capacity gas flow rate is communicated via the first and second opening ports 140, 142 to an outlet 105, and a closed position against the first opening port 140, in which a low-capacity gas flow rate is communicated via only the second opening port 142 to the outlet 105 to thereby provide a consistent low capacity gas flow rate that is within a desired tolerance range. These and other advantages provide novel advantageous improvements over conventional two-stage gas valves.
Thus, it will be understood by those skilled in the art that the above described embodiments and combinations thereof may be employed in various types of heating systems with any combination of the above disclosed features, without implementing the others. It will be understood that the stepper motor driven gas valve and controller described above may be utilized in other forms of heating and cooling equipment, including water heater and boiler appliances. Accordingly, it should be understood that the disclosed embodiments, and variations thereof, may be employed without departing from the scope of the invention.
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| Number | Date | Country | |
|---|---|---|---|
| 20120280157 A1 | Nov 2012 | US |
