COMBINED HEAT AND POWER SYSTEM
A combined heat and power system comprising an electric power generator configured to receive gaseous fuel and output electricity at a voltage level to an electrical grid and hot exhaust, a heat exchanger comprising a water input line, a water output line and a heat exchanger coil connecting the water input line and the water output line, wherein the heat exchanger coil is thermally adapted to the hot exhaust and a blower configured for selectively drawing ambient air to be mixed with the hot exhaust, whereby when hot water is demanded, the blower is not enabled and when hot water is not demanded, the blower is turned on to draw ambient air that is mixed with the hot exhaust such that the temperature of the hot exhaust can be reduced.
This non-provisional application claims the benefit of priority from provisional application U.S. Ser. No. 62/090,405 filed Dec. 11, 2014. Said application is incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION1. The Field of the Invention
The present invention is directed generally to a combined heat and power system. More specifically, the present invention is directed to a combined heat and power system where the electric power generated in the combined heat and power system is configured to be supplied via a municipal or public electrical grid to customers of a local network.
2. Background Art
Most combined heat and power systems have been configured to receive and use gaseous fuel to generate heat and electric power. The generated electric power is used locally to power devices connected within a home or building and not any devices located at a distance on another location on a municipal or public electrical grid. The generated power must be used immediately at the locale within which the combined heat and power system is located without the benefit of storage for later use at the locale or another locale. Therefore, the amount of electric power generated is typically small, e.g., sufficient only for one or two residences and the cost for generating power becomes prohibitively high as the equipment is incapable in providing economy of scale.
Thus, there is a need for a combined heat and power system having a means for sharing its generated power with its neighbors or otherwise consumed or stored economically and thus capable of lowering the cost per unit electric power generated due to economy of scale.
SUMMARY OF THE INVENTIONIn accordance with the present invention, there is provided a combined heat and power system including:
- (a) an electric power generator configured to receive gaseous fuel and output hot exhaust and electricity at a voltage level;
- (b) at least one heat exchanger including a fluid input line, a fluid output line and a heat exchanger coil connecting the fluid input line and the fluid output line and adapted to prepare a hot fluid, wherein the at least one heat exchanger is thermally adapted to the hot exhaust; and
- (c) a blower configured for selectively drawing ambient air to be mixed with the hot exhaust, whereby when the hot fluid is demanded, the blower is not enabled and a fluid is drawn through the fluid input line and delivered at the fluid output line to cause heat recovery from the hot exhaust to the fluid and when the hot fluid is not demanded, the blower is turned on to draw ambient air that is mixed with the hot exhaust such that the temperature of the hot exhaust can be reduced.
In one embodiment, the fluid is water.
In one embodiment, the voltage level is disposed at a level of from about 5 V to about 30 V higher than the supply voltage of a public electrical grid such that electricity generated of the electric power generator may be transmitted via the public electrical grid.
In one embodiment, the electric power generator is a micro turbine. In another embodiment, the electric power generator is a solid oxide fuel cell.
In one embodiment, the electric power generator comprises a common exhaust conductor configured for receiving the hot exhaust.
In one embodiment, the at least one heat exchanger is adapted to receive heat from a burner and output exhaust adapted to be emptied into the common exhaust conductor.
In one embodiment, the common exhaust conductor is a plastic duct.
In one embodiment, the output of the electric power generator is functionally connected to a local network.
An object of the present combined heat and power system is to provide a combined heat and power system capable of producing heat for local consumption and electricity for local consumption and consumption of customers within a local network such that reliance of the customers of the local network on public electrical grid can be reduced or eliminated.
Another object of the present combined heat and power system is to provide a system capable of providing not only heat but also electricity.
Another object of the present combined heat and power system is to provide a system capable of utilizing waste heat from an electric power generator of the combined heat and power system in a water and/or space heating system of the combined heat and power system.
Whereas there may be many embodiments of the present invention, each embodiment may meet one or more of the foregoing recited objects in any combination. It is not intended that each embodiment will necessarily meet each objective. Thus, having broadly outlined the more important features of the present invention in order that the detailed description thereof may be better understood, and that the present contribution to the art may be better appreciated, there are, of course, additional features of the present invention that will be described herein and will form a part of the subject matter of this specification.
In order that the manner in which the above-recited and other advantages and objects of the invention are obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
2—combined heat and power system
4—heat recovery module of an electric power generator, e.g., micro turbine
6—heat exchanger coil
8—electric power generator, e.g., micro turbine
10—hot exhaust of electric power generator, e.g., micro turbine
12—blower
14—ambient air
16—combined water and/or air heating system without burner
18—fluid heating system with burner
20—low temperature exhaust
22—common exhaust conductor
24—fluid input line
26—fluid output line
28—gas supply
30—plate-type heat exchanger
32—circulation pump
34—heat trap
36—bypass valve
38—flow sensor and control valve package
40—buffer tank
42—burner
44—supply line
46—return line
48—heat source
PARTICULAR ADVANTAGES OF THE INVENTIONThe present combined heat and power system eliminates the need for discrete air and/or water heating systems and electric power generators. Combined heating systems and electric power generators enable waste heat from one system to be harnessed and utilized in another, thereby increasing the total efficiency of the combined system. In occasions where such waste heat from the hot exhaust of the power generator cannot be harnessed, the hot exhaust is diluted to yield tempered exhaust that can be carried using lower cost exhaust conductors, e.g., plastic ducts, as compared to stainless steel ducts suitable for carrying exhaust at significantly higher temperatures. As a result, equipment costs can be reduced significantly by using plastic ducts.
The present combined heat and power system supplies electric power to nearby consumers of a network of consumers via existing power lines that are shared between the homes or points of use. No additional and dedicated power lines are necessary.
The losses due to transmission of electric power over short distances, e.g., several hundred feet is much less than the losses incurred due to transmission of power over long distances, e.g., miles to hundreds of miles. Therefore, when power is supplied by a source that is located nearby, the transmission efficiency can be greatly increased.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENTThe term “about” is used herein to mean approximately, roughly, around, or in the region of. When the term “about” is used in conjunction with a numerical range, it modifies that range by extending the boundaries above and below the numerical values set forth. In general, the term “about” is used herein to modify a numerical value above and below the stated value by a variance of 20 percent up or down (higher or lower).
In one embodiment, the electric power generator 8 is a 15 to 20 kW micro turbine. Reference is made to U.S. Pat. No. 6,198,174 entitling “Microturbine power generating system” to Nims et al. for a micro turbine suitable for use in the present combined heat and power system. According to Wikipedia website, “Micro turbines are small-in-size electricity generators that burn both gaseous and liquid fuels to create high-speed rotation, which turns an electrical generator.”
In another embodiment, the electric power generator 8 is a solid oxide fuel cell. Reference is made to U.S. Pat. No. 5,741,605 entitling “Solid oxide fuel cell generator with removable modular fuel cell stack configurations” to Gillett et al. for a solid oxide fuel cell suitable for use in the present combined heat and power system. According to Wikipedia website, “a solid oxide fuel cell (or SOFC) is an electrochemical conversion device that produces electricity directly from oxidizing a fuel. Fuel cells are characterized by their electrolyte material; the SOFC has a solid oxide or ceramic, electrolyte. Advantages of this class of fuel cells include high efficiency, long-term stability, fuel flexibility, low emissions, and relatively low cost. The largest disadvantage is the high operating temperature which results in longer start-up times and mechanical and chemical compatibility issues”
In one embodiment, further economic benefits may be realized when each consumer participating in a lower power distribution scheme is capable of scheduling its power usage based on the most favorable energy pricing or availability of locally generated electric power at a particular time of day. For instance, if at peak power production, a total of twenty appliances, e.g., Internet of Things (commonly known as IOT) devices across the local network of consumers may be turned on at the same time due to power generating limitations of the local combined heat and power system, a request to turn on an additional appliance using the locally provided electric power may be declined. The request may be scheduled to be met at a later time when the operations of other appliances have concluded. Reference is made to Applicants' co-pending application U.S. Pat. Pub. No. 2012/0191256 entitling “Masterless control system methods for networked water heaters” for a mechanism useful for controlling appliances over a network of consumers. Appropriate parameters of the network, e.g., usage of a water heating system, may be manipulated to prevent or allow the activation of the water heating system.
The detailed description refers to the accompanying drawings that show, by way of illustration, specific aspects and embodiments in which the present disclosed embodiments may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice aspects of the present invention. Other embodiments may be utilized, and changes may be made without departing from the scope of the disclosed embodiments. The various embodiments can be combined with one or more other embodiments to form new embodiments. The detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, with the full scope of equivalents to which they may be entitled. It will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of embodiments of the present invention. It is to be understood that the above description is intended to be illustrative, and not restrictive, and that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Combinations of the above embodiments and other embodiments will be apparent to those of skill in the art upon studying the above description. The scope of the present disclosed embodiments includes any other applications in which embodiments of the above structures and fabrication methods are used. The scope of the embodiments should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
Claims
1. A combined heat and power system comprising:
- (a) an electric power generator configured to receive gaseous fuel and output hot exhaust and electricity at a voltage level;
- (b) at least one heat exchanger comprising a fluid input line, a fluid output line and a heat exchanger coil connecting said fluid input line and said fluid output line and adapted to prepare a hot fluid, wherein said at least one heat exchanger is thermally adapted to the hot exhaust; and
- (c) a blower configured for selectively drawing ambient air to be mixed with the hot exhaust, whereby when the hot fluid is demanded, said blower is not enabled and a fluid is drawn through said fluid input line and delivered at said fluid output line to cause heat recovery from the hot exhaust to the fluid and when the hot fluid is not demanded, said blower is turned on to draw ambient air that is mixed with the hot exhaust such that the temperature of the hot exhaust can be reduced.
2. The combined heat and power system of claim 1, wherein said voltage level is disposed at a level of from about 5 V to about 30 V higher than the supply voltage of a public electrical grid such that electricity generated of said electric power generator may be transmitted via the public electrical grid.
3. The combined heat and power system of claim 1, wherein said electric power generator is a micro turbine.
4. The combined heat and power system of claim 1, wherein said electric power generator is a solid oxide fuel cell.
5. The combined heat and power system of claim 1, wherein said electric power generator comprises a common exhaust conductor configured for receiving the hot exhaust.
6. The combined heat and power system of claim 5, wherein said at least one heat exchanger is adapted to receive heat from a burner and output exhaust adapted to be emptied into said common exhaust conductor.
7. The combined heat and power system of claim 5, wherein said common exhaust conductor is a plastic duct.
8. The combined heat and power system of claim 1, wherein said fluid is water.
9. The combined heat and power system of claim 1, wherein the output of said electric power generator is functionally connected to a local network.
10. A combined heat and power system comprising:
- (a) an electric power generator configured to receive gaseous fuel and output hot exhaust and electricity at a voltage level disposed at a level of from about 5 V to about 30 V higher than the supply voltage of a public electrical grid such that electricity generated of said electric power generator may be transmitted via the public electrical grid;
- (b) at least one heat exchanger comprising a fluid input line, a fluid output line and a heat exchanger coil connecting said fluid input line and said fluid output line and adapted to prepare a hot fluid, wherein said at least one heat exchanger is thermally adapted to the hot exhaust; and
- (c) a blower configured for selectively drawing ambient air to be mixed with the hot exhaust, whereby when the hot fluid is demanded, said blower is not enabled and a fluid is drawn through said fluid input line and delivered at said fluid output line to cause heat recovery from the hot exhaust to the fluid and when the hot fluid is not demanded, said blower is turned on to draw ambient air that is mixed with the hot exhaust such that the temperature of the hot exhaust can be reduced.
11. The combined heat and power system of claim 10, wherein said electric power generator is a device selected from the group consisting of a micro turbine and a solid oxide fuel cell.
12. The combined heat and power system of claim 10, wherein said electric power generator comprises a common exhaust conductor configured for receiving the hot exhaust.
13. The combined heat and power system of claim 12, wherein said at least one heat exchanger is adapted to receive heat from a burner and output exhaust adapted to be emptied into said common exhaust conductor.
14. The combined heat and power system of claim 12, wherein said common exhaust conductor is a plastic duct.
15. The combined heat and power system of claim 10, wherein said fluid is water.
16. A combined heat and power system comprising:
- (a) an electric power generator configured to receive gaseous fuel and output hot exhaust and electricity at a voltage level;
- (b) at least one heat exchanger comprising a water input line, a water output line and a heat exchanger coil connecting said water input line and said water output line adapted to prepare a hot water supply, wherein said at least one heat exchanger is thermally adapted to the hot exhaust; and
- (c) a blower configured for selectively drawing ambient air to be mixed with the hot exhaust, whereby when the hot water supply is demanded, said blower is not enabled and a water flow is drawn through said water input line and delivered at said water output line to cause heat recovery from the hot exhaust to the water flow and when the hot water supply is not demanded, said blower is turned on to draw ambient air that is mixed with the hot exhaust such that the temperature of the hot exhaust can be reduced.
17. The combined heat and power system of claim 16, wherein said voltage level is disposed at a level of from about 5 V to about 30 V higher than the supply voltage of a public electrical grid such that electricity generated of said electric power generator may be transmitted via the public electrical grid.
18. The combined heat and power system of claim 16, wherein said electric power generator is a device selected from the group consisting of a micro turbine and a solid oxide fuel cell.
19. The combined heat and power system of claim 16, wherein said electric power generator comprises a common exhaust conductor configured for receiving the hot exhaust.
20. The combined heat and power system of claim 19, wherein said common exhaust conductor is a plastic duct.
Type: Application
Filed: Dec 11, 2015
Publication Date: Jun 16, 2016
Inventors: Sridhar Deivasigamani (Peoria, IL), Sivaprasad Akasam (Dunlap, IL)
Application Number: 14/966,122