This application is directed, in general, to a fireplace and, more specifically, to a modulating flame gas fireplace.
Even with the advent of central heat, many homes and business still use fireplaces. In some instances, they are used to produce additional heat for a given space, however, in other applications, their presence is purely aesthetic. Many of the advances in fireplace technology have primarily been in the arena of providing fireplace systems that are designed to better transfer the heat generated by the fire. This has particularly been the case with the advent of natural gas fireplaces that are much cleaner and more convenient than conventional wood-burning fireplaces.
One aspect provides a fireplace insert comprising: a gas burner, a fuel/air control valve coupled to the gas burner, a blower coupled to the gas burner, and a controller coupled to the fuel/air control valve and the blower; wherein the controller controls at least one operational parameter of the fuel/air control valve and the blower to produce a flame pattern generated by the gas burner.
A method of manufacturing a fireplace insert comprising: providing a gas burner, coupling a fuel/air control valve to said gas burner, coupling a blower to said gas burner, and coupling a controller to said fuel/air control valve and said blower wherein said controller controls at least one operational parameter of said fuel/air control valve and said blower to produce a flame pattern generated by said gas burner.
Reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
In certain embodiments, the fuel/air control valve 120, the blower 130, and the controller 140 of the fireplace insert 100 may be powered by conventional line voltage of 110-115 VAC. However, in other embodiment, the fuel/air control valve 120, the blower 130, and the controller 140 may be powered by direct current. The blower 130 is pneumatically coupled to the gas burner 110 through a duct 160, such as gas pipes, which has the fuel/air control valve 120 interposed the blower 130 and the gas burner 110. The controller 140 comprises a microprocessor with a programmable memory for controlling at least one operational parameter of the fuel/air control valve 120 and the blower 130. In one embodiment, the controller 140 may command a set program over a specified period of time and then cyclically repeat the program. In another embodiment, the controller 140 may be set to command a varying function so as to give the appearance of a traditional wood fireplace with varying flame colors and heights. In an alternative embodiment, the controller 140 may be replaceable as a complete unit or a plug-in board, each different unit having a specific program preprogrammed. Alternatively, the controller 140 may be reprogrammed through a USB connection to a personal computer.
The operational parameters of the fuel/air control valve 120 and the blower 130, in certain embodiments, may include the following: fuel (natural gas or propane) velocity, air velocity, fuel/air ratio, and an equivalence ratio. The fuel velocity may be controlled by setting the fuel/air control valve 120 with the controller 140 sensing the line gas pressure and adjusting the fuel/air control valve 120 appropriately. The air velocity may be controlled by the rotation speed of the blower 130 and the setting of the fuel/air control valve 120 by the controller 140. The fuel/air ratio may be controlled by the controller 140 when it sets the fuel/air control valve 120 for the proper mix to obtain a desired fuel/air ratio. The equivalence ratio φ is defined as: (F/A ratio)actual divided by (F/A ratio)stoichiometric. One who is of skill in the art is familiar with the meaning of a stoichiometric fuel/air ratio. The equivalence ratio may be determined by the controller 140 for appropriate adjustment as necessary for a desired flame pattern or color.
The operational parameters of the fuel/air control valve 120 and the blower 130 can affect the flame pattern. For example, if a constant fuel/air ratio is maintained, but the volume of fuel and air is increased, the length of the flame will increase. That is, height h of the flame pattern is a direct function of the volume of fuel and air delivered to the burner 110 by the blower 130. If the constant fuel/air ratio is maintained, but the volume of fuel and air is decreased, the length of the flame will also decrease. If the flow volume of fuel and air is increased by increasing fuel while holding the air constant, then the flame will tend to be more yellow in color. If the opposite is commanded, i.e., the flow volume of fuel and air is increased by increasing air while holding the fuel volume constant, then the flame will tend to be more toward blue in color. These various operational parameters of the fuel/air control valve 120 and the blower 130 are controlled by the controller 140 adjusting the fuel/air mixture with the fuel/air control valve 120 and the flow volume by increasing or decreasing the rotational speed of the blower 130. By adjusting one or more of the operational parameters, a very artistic flame having different heights, colors, or both over a programmed period of time may be easily achieved. The time may be varied in such a way so to create a constant changing flame or produce repeated patterns over a set period of time, much in the same way as a water fountain might be operated.
As with previous embodiments, the operational parameters of the fuel/air control valve 320 and the blower 330 can be varied to affect the flame pattern and be operated and controlled by way of the controller 340 in the manner described above, such that by adjusting one or more of the operational parameters, a very artistic flame having different heights, colors, or both over a programmed period of time may be easily achieved. The time may be varied in such a way so to create a constant changing flame or produce repeated patterns over a set period of time, much in the same way as a water fountain might be operated.
Thus, a fireplace insert has been described that controls not only the height of the flame pattern emanating from multiple burners, but also, the shape and color of the flames.
For the purposes of this discussion, use of the terms “providing” and “forming” includes: manufacture, subcontracting, purchase, etc. Those skilled in the art to which this application relates will appreciate that other and further additions, deletions, substitutions and modifications may be made to the described embodiments.