US20080223945A1

US20080223945A1 - Heat exchanger

Info

Publication number: US20080223945A1
Application number: US12/047,045
Authority: US
Inventors: George H.K. Lau; Chi Ming Gavin Tham
Original assignee: FPI Fireplace Products International Ltd
Current assignee: FPI Fireplace Products International Ltd
Priority date: 2007-03-12
Filing date: 2008-03-12
Publication date: 2008-09-18

Abstract

Provided are exemplary embodiments, which may include a heating system with one or more heat exchangers. The heat exchangers may be capable of transferring heat in, to, and/or from the heating system to reduce inefficiencies, and/or allow the heating system to operate in a relatively more efficient manner.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to and benefit of U.S. Provisional Application No. 60/894,409, entitled “Heat Exchanger” and filed on Mar. 12, 2007.

TECHNICAL FIELD

The present disclosure relates, generally, to heating systems and, in particular, to a heat transfer of a heating system.

BACKGROUND

Various heating systems, including fireplaces and furnaces for home installations, may have been made available to consumers in recent years with improved control systems. Despite improvements, such heating systems may be limited in the ability to control the heat distribution from the heating system to the area to be heated.
For example, while current heating systems have frequently utilized various techniques to separate the combustion air from the room air, such as direct air venting systems, very little has been done to improve heat transfer and distribution, and/or increase the efficiency of the system. This efficiency may include the amount of heat transferred to the surrounding area.

SUMMARY

In accordance with various aspects of exemplary embodiments, a heating system may include heat exchangers, such that the heating system may operate more efficiently. In accordance with an exemplary embodiment, an exemplary heating system may include a combustion air path, a convection air path, as well as other pathways for air and/or heat exchanging configurations. The heating system may include various types of heating configurations, such as fireplaces, stoves, furnaces or other like heating systems. An air intake is configured to receive external air into the heating system, while an exhaust vent is configured to remove exhaust from within the heating system. Both the air intake and exhaust vent can be configured in various manners, shapes and sizes for providing the respected air intake and exhaust removal functions, as well as heat exchange.
In accordance with one aspect of exemplary embodiments, the heating system may be configured to include heat exchangers to increase the efficiency of the system.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary embodiments may be described in conjunction with the appended drawing figures in which like numerals denote like elements and:

FIG. 1 is a diagram of an exemplary heating system according to an exemplary embodiment;

FIG. 2 is a perspective view of an exemplary heat exchanger according to an exemplary embodiment;

FIG. 3 is a user interface according to an exemplary embodiment.

DETAILED DESCRIPTION

The present disclosure may describe various functional components. It should be appreciated that such functional components may be realized by any number of hardware components, electrical and mechanical, configured to perform the specified functions. In addition, exemplary embodiments may be practiced in any number of heating system contexts, and the fireplace systems described herein are merely one exemplary application.
Referring now to FIG. 1, in accordance with an exemplary embodiment, a solid fuel heating device 10 having a combustion chamber 12 is illustrated. In an embodiment, a heat exchange arrangement in the form of hollow pipes 19 can be disposed towards the top end of combustion chamber 12 and may be heated hot air from combustion chamber 12. Ambient air, as indicated by arrows 22, may be circulated through hollow pipes 19 by a fan 21 mounted in a side wall of the heating device, or any other convenient location, such as proximate the hot air exhaust area, to exhaust heated air 20 from pipes 19 into the ambient air, in a direction indicated by arrows 22. This may be accomplished to heat the surrounding area of heating device 10. Fan 21 may be configured in various locations for circulating ambient air through pipes 19, with such pipes 19 being arranged in various manners for discharging heat to the surrounding area.
In an embodiment, the convection, combustion and/or air inlet air flow pathways and/or systems may also be used in other manners by utilizing heat transfer devices to extract heat, including flat and/or accordion plate heat exchangers, air flow passages for exhaust and/or convection air, casting, hot air intake, and/or other methods and systems for discharging heat to the surrounding area. The utilization of heat exchangers with a stove may increase the efficiency of the system, increase the convection temperature, and/or lower the exhaust temperature, and/or combinations thereof. Heat exchangers may be utilized in many portions of the heating system to generally reduce inefficiencies.
Furthermore, combustion and convection air flow may be configured to be parallel, counter, and/or cross flow, and/or combinations thereof to further increase efficiency. In an embodiment, heat exchange between the convection and combustion air, heat exchange between the air intake and the exhaust air, mixing the exhaust air with the air intake, etc. may make the system more efficient.
Heating system 10, as herein illustrated in the exemplary embodiment, may be a biomass pellet, fuel, and/or grain-fed, and/or other fuel, and/or combinations thereof, space-heating stove. The system may include a “key,” which may allow the system to utilize different fuels. The key may be added to allow the use of various type of fuel. The system may allow a user to switch fuel type without shutting down the system.
In an embodiment, system 10 may include a hopper 23. Hopper 23 may be configured for storage of fuel sources, such as solid fuel pellets 24, for example. Hopper 23 may be various sizes, shapes, and configurations for storage of fuel. In an exemplary embodiment, fuel pellets 24 may be fed into a fuel bed 25 of combustion chamber 12 by an auger 26 feeding a chute 27.
In the exemplary embodiment, solid fuel pellets 24 entering combustion chamber 12 may be projected into fuel bed 25 by gravity and supported by a support mechanism in the form of a support tray 28. Support tray 28 may be fixedly secured under the bottom, open end of the inner wall 16. An ash collecting tray 29 may be removably secured under this support tray 28 and accessible through a door 30. A sensor may be included, which may alert a user that the ash pan is full. This may indicate that the pan should be emptied. If the pan is not emptied, the system may shut down, or other sequence, to protect the system.
Solid fuel pellets and grains (fuel) 24 may also be fed from the bottom or the side of the unit, or any other configuration for providing fuel, and the like, onto fuel bed 25. For example, rather than hopper 23 and/or auger 26, many other mechanisms or systems for conveying materials may be suitably implemented.
The system may be capable of operating a high-efficiency burn mode, or a clean burn mode, which may be user selectable.
Shown in FIG. 2 is a perspective view of an exemplary heat exchanging device 100. In an embodiment, device 100 may be utilized through the heating system to increase efficiency. Device 100 may include a generally cylindrical portion 102 and a generally irregular surfaced portion 104. Multiple devices 100 will be located in areas 19 and 20 of FIG. 1.
As seen in FIG. 2, the irregular surfaced portion 104 is typically configured with more surface area than the cylindrical portion 102. However, the configuration of the irregular surfaced portion 104 shown in FIG. 2 is not meant to be limiting. While the irregular surfaced portion 104 portion is show having multiple fins, it should be understood that other suitable configurations may also be utilized as will be further discussed below.
In operation, cool convection air passes thru an internal part of this device 100. The convection air is then heated by the exhaust passing thru the irregular surfaced portion 104. The design of the irregular surfaced portion 104 provides more heat transfer than standard somewhat smooth and/or regular surfaced heat exchangers. As such, the design of the irregular surfaced portion 104 allows more heat to be transferred generally from the interior of the device 100 to the exterior of the device 100.
It should be understood that the device 100 can be made by extrusion method using aluminum. The device 100 may also be cast into various shapes using different materials based on the geometry that meets the design needs. As such it should further be understood that multiple configurations of the irregular surfaced portion 104 may be used based on design configurations. Some examples include but are not limited to accordion-type, flat-type, corrugated-type, heat pipe-type, and spiral plated-type configurations.
Many different types and configurations of heat exchangers may be utilized with the system. A corrugated surface plate, or a casting made from copper or other high heat transfer coefficient material may be positioned between different air flows to enhance heat transfer. Utilizing finned tubes may further increase the surface area and increase the heat transfer characteristics of the system. Furthermore, the alteration of the air flow devices to create turbulence or other disruption may further increase efficiency.
Other types of heat exchangers, such as heat pipes, or condensers may also be utilized to enhance heat transfer, as they may utilize the phase shifts of fluids to release heat at a much higher rate. Furthermore, there may be other heat exchangers that enhance heat transfer such as coaxial venting, radiator, spiral plated exchangers, and/or any other heat exchanger that may enhance heat transfer.
Referring now to FIGS. 1 and 3 in accordance with exemplary embodiments, user interface 61 includes a keypad-type configuration, with a display 76. In embodiments, display 76 may be an LED-type display, and/or an LCD-type display. Other display types may be utilized without straying from the concepts disclosed herein.
Furthermore, user interface 61 may be configured to allow a user to control and/or manipulate the operation of the solid fuel biomass pellet heating device 10, such as the system illustrated in FIG. 1.
Controller 60 may be configured to control the motor(s) and the fans, and inputs and operating parameters utilizing information from sensors located throughout the system. To start the operation of a biomass pellet device 10, a user may actuate the button labeled “Start” 78. This may cause the pellets to be automatically fed to the burner and ignited by an ignition device, to create an initial fuel bed. Other steps may then be accomplished to start the operation of heating system 10, such as starting the system with a fire starter, and/or starting with one fuel and continuing the burn with another fuel. Other ignition methods may be utilized, including utilization of an air pump and/or an igniter to assist in creating a torch effect, and/or more than one ignition source. Furthermore, a user may turn off the heating deice by depressing the button labeled “Stop” 80.
In an embodiment, the “Service” actuator 82 may activate diagnostics for the system. The diagnostics may include tuning the bum to compensate for atmospheric conditions, and/or variations in fuel, and fuel quality. It will be appreciated that the diagnostics of the system may include many other diagnostics.
In an embodiment, the user may select a desired mode of operation of device 10 by inputting desired parameters into the controller by the use of interface pad 61. Interface pad 61 can also be provided with heat level buttons 73, which may control the amount of heat produced by the system. This may increase or decrease the temperature in combustion chamber 12. This increase may cause an increase in the temperature of the heated air released by the biomass pellet device through the heat exchanger located above the flame, which may be regulated by a separate fan. All of these operating parameters may be capable of being stepped up or down, to maintain relatively optimum performance levels and/or to decrease inefficiencies of the system, according to the desired heat performance required of the device.
Additionally, the entire system can operate from a remote thermostat to regulate all of these operating parameters based at least in part upon the setting(s) of the thermostat. User interface 61 may also be removed from the system and be used remotely. A “Prime Stove” actuator 72 may be provided, which may be capable of activating a method for manually priming the heating device. This may be due to the various types and/or qualities of the fuel being utilized. Priming may not be necessary for all fuels, types, and/or qualities.
Inputs from actuators may be sent to the controller, which may regulate the speed of the motor, which drives the ash auger. Control switches 73 may also be utilized to set a desired BTU output of the pellet stove. Through the software of the controller, the type of fuel and substantially optimal operating conditions of the device may be regulated and maintained.
User interface 61 may also include a fuel selection button 70, which may be configured to indicate to the controller the fuel that will be used. Different choices for fuel may appear within display 64. The user may then depress “Heat” actuator 74, which may allow a user to adjust the heat level using buttons 73. This may allow the controller to control various aspects of the system based at least in part upon the type of fuel being used by the system. In an embodiment, the types of fuel shown are solid fuels. However, other fuels, such as non-solid fuels, may also be utilized.
User interface 61 may be attached to the system, or may be a remote control. Furthermore, user interface 61 may also be capable of communicating with other devices within the heating environment to further control the operation of the system. In one embodiment, another device may be a temperature sensor that may interface with the system.
The present invention sets forth a heat transfer controller that is applicable to various heating system applications. It will be understood that the foregoing description is of exemplary embodiments of the invention, and that the invention is not limited to the specific forms shown. Various modifications may be made in the design and arrangement of the elements set forth herein without departing from the spirit and scope of this disclosure. For example, the sensors utilized are not limited to those shown herein. Furthermore, other user interfaces may be utilized as well. Many other processors/controllers, as well as sensors may be utilized without straying from the concepts disclosed herein. These and other changes or modifications are intended to be included within the scope of the present invention, as set forth in the following claims.

Claims

1. A heating system, comprising:

a combustion air pathway capable of allowing air to pass to a combustion chamber;

a convection air pathway capable of receiving heat from the system and heating the area surrounding the heating system;

an air intake pathway capable of allowing air to enter the heating system, and one or more heat exchangers configured in the combustion, air intake, and/or the convection air pathways, capable of exchanging heat to decrease inefficiency of the heating system.

2. The heating system according to claim 1, wherein the one or more heat exchangers comprises at least one of an accordion-type, flat-type, corrugated-type, heat pipe-type, spiral plated-type, and finned-type configuration.

3. The heating system according to claim 1, wherein the one or more heat exchangers comprises at least on of a condenser, a radiator, a high heat coefficient material, and a cast material.

4. The heating system according to claim 3, wherein the one or more heat exchangers comprises a generally liquid material.

5. The heating system according to claim 3, wherein the cast material comprises at least one of copper and aluminum.

6. The heating system according to claim 1, wherein the air pathways are configured in at least one of a parallel flow configuration, a cross flow configuration, and a counter flow configuration.

7. The heating system according to claim 1, wherein air flow from the air pathways is mixed.

8. The heating system according to claim 1, wherein turbulence occurs in the air flow in the air pathways.

9. The heating system according to claim 1, wherein a disruption occurs in the air flow in the air pathways.

10. The heating system according to claim 1, further comprising a coaxial vent.

11. A pellet stone heating system, comprising:

an air intake pathway capable of allowing air to enter the heating system, and

one or more heat exchangers configured in the combustion, air intake, and/or the convection air pathways, capable of exchanging heat to generally decrease the inefficiency of the heating system, wherein the one or more heat exchangers comprises at least one of an accordion-type, flat-type, corrugated-type, heat pipe-type, spiral plated-type, and finned-type configuration.

12. The heating system according to claim 11, wherein the one or more heat exchangers comprises at least one of a condenser, a radiator, a high heat coefficient material, and a cast material.

13. The heating system according to claim 12, wherein the one or more heat exchangers comprises a liquid material.

14. The heating system according to claim 12, wherein the cast material comprises at least one of copper and aluminum.

15. The heating system according to claim 11, wherein the air pathways are configured in at least one of a parallel flow configuration, a cross flow configuration, and a counter flow configuration.

16. The heating system according to claim 11, wherein air flow from the air pathways is mixed.

17. The heating system according to claim 11, wherein turbulence occurs in the air flow in the air pathways.

18. The heating system according to claim 11, wherein a disruption occurs in the air flow in the air pathways.