This application relates generally to steam oven steam generators incorporating a heater control that limits peak power consumption.
Steam generators are used in a variety of applications such as steam cooking systems in which the steam is supplied to a steam cooking cavity. Many such steam generators are used in high volume situations. A typical steam generator includes a heating chamber (e.g., within a tank) with an associated heating element (e.g., electric heating element) that is used to heat water within the tank. As steam is produced and exits the tank (e.g., for delivery to a steam oven cooking chamber), water is added back into the tank. By way of example, U.S. Patent Publication No. US2019/0282020 describes an exemplary steam oven and steam generator, and such publication is incorporated herein by reference in its entirety.
Typically, the heating element is energized at a variable power level to maintain a set water temperature within the steam generator (e.g., at or above 212° F.) and water level sensors are used to determine when to add water to the tank (e.g., when the water level reaches a low level limit) and when to stop adding water to the tank (e.g., when the water level reaches a high level limit). When the water level reaches the low limit level and water starts to be added, the steam generator temperature drops rapidly, causing the temperature control to rapidly jump to full power level in attempt to bring the water temperature back up. Operating the steam generator heating element at its peak power level is undesired due to the impact on peak load time of the facility in which the steam oven is operating, resulting in increased utility bills for the facility.
It would be desirable to provide a steam oven steam generator with a heater control with reduced peak power consumption.
In one aspect, a steam cooker includes a steam cooking chamber and a steam generator external of the steam cooking chamber and plumbed to deliver steam from a steam outlet of the steam generator to a steam inlet of the steam cooking chamber. The steam generator includes a tank structure providing a heating chamber for holding water, an electric heating system associated with the tank structure for heating water within the heating chamber so as to generate steam, a fill line for selectively adding water to the tank; and a controller configured to control the electric heating system and the fill line. The controller is configured to increase a power level of the electric heating system, based upon a water level in the tank and prior to controlling the fill line to add water to the tank, so as to increase steam generator temperature prior to water add.
In another aspect, a steam cooking system includes a steam cooking chamber and a steam generator plumbed to deliver steam to the steam cooking chamber. The steam generator includes a tank structure providing a heating chamber for holding water, a heater associated with the tank structure for heating water within the heating chamber so as to generate steam, at least one water level sensor associated with the tank, a fill line for selectively adding water to the tank, and a controller configured to control the heater and the fill line. The controller is configured to control a power level of the heater based at least in part upon a water level in the tank as indicated by the at least one water level sensor, so as to increase steam generator temperature prior to water add.
In a further aspect, a steam cooking system includes a steam cooking chamber and a steam generator plumbed to deliver steam to the steam cooking chamber. The steam generator includes a tank structure providing a heating chamber for holding water, a heater associated with the tank structure for heating water within the heating chamber so as to generate steam, at least one water level sensor associated with the tank, a temperature sensor, a fill line, and a controller configured to control the heater. The controller is configured to control a power level of the heater based upon both a temperature indicated by the temperature sensor and a water level indicated by the at least one water level sensor, so as to increase steam generator temperature prior to water add.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.
Referring to
The steam generator 5 includes a tank 10 with an associated fill line 12 and water fill valve 14. One or more sensor(s) 16 are located to detect the water level in the tank. A temperature sensor 18 is provided, and one or more electrical heater(s) 20 are located for heating water in the tank (e.g., submerged with the water in the tank). A controller 22 is configured to control both a state of the water fill valve 14 and power level of the electrical heater(s) 20 of the tank. As used herein, the term controller is intended to broadly encompass any circuit (e.g., solid state, application specific integrated circuit (ASIC), an electronic circuit, a combinational logic circuit, a field programmable gate array (FPGA)), processor(s) (e.g., shared, dedicated, or group—including hardware or software that executes code), software, firmware and/or other components, or a combination of some or all of the above, that carries out the control functions of the device or the control functions of any component thereof.
The controller 22 is configured to operate the heater(s) 20 such that the power level is increased prior to adding water to the tank, even though the typical temperature-based control algorithm does not call for such a power level increase. The flow chart of
In an alternative configuration, per
As suggested in
In both of the control embodiments contemplated by
Likewise, in both control embodiments, the controller is configured to control a power level of the heater based upon both a temperature indicated by the temperature sensor and a water level indicated by the at least one water level sensor, so as to increase steam generator temperature prior to water add. In particular, the controller is configured to control the power level of the heater based upon the temperature indicated by the temperature sensor so as to maintain the temperature at a preset temperature level (e.g., a range around boiling), until the water level indicated by the at least one water level sensor reaches a threshold low level (e.g., the intermediate level in the case of 2 or the low limit level in the case of
It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible. For example, the advantageous heater control scheme for the steam generator could be implemented in cooking devices that include other cooking technologies as well (e.g., combination ovens). All such devices, whether steam only or steam in combination with other cooking technologies, are deemed steam cookers or steam cooking systems, as those terms are used herein.
Number | Date | Country | |
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63239996 | Sep 2021 | US |