US-12624830-B2 - Burner system and method for providing thermal energy

US12624830B2US 12624830 B2US12624830 B2US 12624830B2US-12624830-B2

Abstract

The present invention relates to a burner system for providing thermal energy comprising an evaporator device for evaporating a liquid alcohol fuel, a burner air supply means, a burner device for burning a fuel mixture comprising vaporized fuel and burner air to provide an exhaust gas stream, a functions device for controlling the thermal energy of the exhaust gas flow, wherein the burner device provides the thermal energy for evaporation in the evaporator device during operation.

Inventors

Martin Großgasteiger
Marco Neumann
Matthias Wößner
Eilhard Stohldreier
Mark Dougall Berninger

Assignees

SIQENS GMBH

Dates

Publication Date: 20260512
Application Date: 20191220
Priority Date: 20181221

Claims (13)

1 . A burner system for providing thermal energy, the burner system comprising: an evaporator device for vaporizing a liquid fuel and providing completely vaporized fuel, a burner air supply device for providing burner air, a surface burner for burning a fuel mixture comprising the completely vaporized fuel and the burner air to provide an exhaust gas stream, a shielding plate with openings for passing and controlling the thermal energy of the exhaust gas stream of the surface burner, wherein the surface burner is coupled to the evaporator device via the shielding plate in such a way that, in operation, the exhaust gas flow of the surface burner provides the thermal energy and the evaporation temperature required for complete evaporation of the fuel in the evaporator device, wherein the shielding plate is provided for radiation shielding of the evaporator device as well as for mixing the hot burner exhaust gas stream with tertiary air in order to reduce a temperature of exhaust gas, so that the overall temperature of the exhaust gas is cooled to a desired suitable level for complete evaporation, and a tertiary air supply device for supplying the tertiary air to the exhaust gas stream to adjust a temperature of the exhaust gas stream by mixing with the tertiary air to form a hot gas stream, wherein the tertiary air supply device is arranged to convey the tertiary air into the exhaust gas stream between the shielding plate and the evaporator device.
2 . The burner system according to claim 1 , wherein the thermal energy of the exhaust gas flow can be provided in the form of diluted exhaust gas, and this thermal energy is delivered in the form of tempered air directly or via a separately designed heat exchanger device to a device coupled to the burner system, this device being an internal combustion engine or a fuel cell stack or a battery.
3 . The burner system according to claim 1 , wherein the surface burner comprises a burner screen and a metal or ceramic fiber mesh connected together, a diffuser, an ignition device and a flame monitoring device.
4 . The burner system according to claim 1 , wherein the burner air supply device is a primary/secondary air supply device which is provided for supplying primary air in order to form the fuel mixture, this being supplied to the fuel vapor prior to combustion, and/or which is provided for supplying secondary air for cooling the burner device, in particular a diffuser and/or a combustion chamber and/or for post-combustion.
5 . The burner system according to claim 1 , wherein the shielding plate comprises openings for passing through and controlling the thermal energy of the exhaust gas flow and/or thermally shields the evaporator device.
6 . The burner system according to claim 1 , wherein the evaporator device is of closed design, wherein the evaporator device comprises an evaporator space for evaporating the liquid fuel, and wherein an outlet of the evaporator device is connected to an inlet of the burner device only via a conduit section, and the evaporator device has an inlet for supplying liquid fuel.
7 . The burner system according to claim 1 , wherein a 3/2-way valve is arranged in a line section which connects an outlet of the evaporator device with a fuel inlet of the burner device.
8 . The burner system according to claim 1 , wherein the shielding plate, the surface burner, and the evaporator device are positioned within a housing with the shielding plate positioned between and spatially separating the surface burner and the evaporator device, and the surface burner directs the exhaust gas stream through the shielding plate toward the evaporator device.
9 . The burner system according to claim 8 , wherein the surface burner operates in radiation mode, and the shielding plate is a baffle plate that provides radiation shielding between the evaporator device and the surface burner.
10 . A burner system for providing thermal energy, the burner system comprising: an evaporator device for vaporizing a liquid fuel and providing completely vaporized fuel, a burner air supply device for providing burner air, a surface burner for burning a fuel mixture comprising the completely vaporized fuel and the burner air to provide an exhaust gas stream, a shielding plate with openings for passing and controlling the thermal energy of the exhaust gas stream of the surface burner, wherein the surface burner is coupled to the evaporator device via the shielding plate in such a way that, in operation, the exhaust gas flow of the surface burner provides the thermal energy and the evaporation temperature required for complete evaporation of the fuel in the evaporator device, wherein the shielding plate is provided for radiation shielding of the evaporator device as well as for mixing the hot burner exhaust gas stream with tertiary air in order to reduce a temperature of exhaust gas, so that the overall temperature of the exhaust gas is cooled to a desired suitable level for complete evaporation, and a tertiary air supply for supplying the tertiary air to the exhaust gas stream to adjust a temperature of the exhaust gas stream by mixing with the tertiary air to form a hot gas stream, wherein the tertiary air supply is arranged between the shielding plate and the evaporator device, wherein positions of the openings of the shielding plate are based on positions of corresponding inflow openings of a tertiary air duct into a mixing chamber where the exhaust gas stream is mixed with the tertiary air to form the hot gas stream.
11 . The burner system according to claim 10 , wherein the openings of the shielding plate are positioned to lie directly adjacent to corresponding inflow openings, and the exhaust gas stream meets the tertiary air at an angle of 90°.
12 . The burner system according to claim 1 , wherein the tertiary air supply device directs the tertiary air to mix with the exhaust gas stream between the evaporator device and the shielding plate to form the hot gas stream, which then flows through or around a heat exchanger of the evaporator device.
13 . The burner system according to claim 12 , wherein the tertiary air supply device cools the exhaust gas stream by providing the tertiary air to the exhaust gas stream based on the evaporation temperature.

Description

RELATED APPLICATIONS This application is a § 371 National Phase Application of International Application No. PCT/EP2019/086556, filed on Dec. 20, 2019, now International Publication No. WO 2020/127892 A1, published on Jun. 25, 2020, which International Application claims priority to German Application 10 2018 133 529.6, filed on Dec. 21, 2018, both of which are incorporated herein by reference in their entirety. The present invention relates to a burner system and a method for providing thermal energy. In the case of fossil energy sources, such as coal, gas and oil, the carbon present is irreversibly converted into carbon dioxide during combustion, thus promoting the greenhouse effect, which leads to global warming. One alternative to these energy sources is methanol. Methanol is a very widely used industrial chemical that is less popular as a fuel in Europe and the USA. In addition to its use as a fuel, methanol can be used as an energy store through chemical reaction. The function of an energy store is based on its controlled absorption of an amount of energy that can be released again with a time delay. Surface burners are increasingly being used for low-power burners, especially burners for domestic heating. With this principle, the burner head consists of a porous material. High-heat-resistant metal or ceramic fiber is usually used for this. Fuel and air are premixed and burn as they flow through the burner head. Due to the small flow channels, the heat of reaction is well convected to the material of the burner head. The heat radiates from the burner head to the walls of the boiler. The annealing temperature of the burner head is set between 700° C. and 900° C. In this temperature range, the formation of thermal NOx is inhibited. The burners are thus characterized by extremely low NOx emissions. In terms of the shape of the burner head, burners are divided into flat burners, cylindrical burners and hemispherical burners. A “ceramic foam burner” is known as a flat-surface burner head. In this burner, a gas-air mixture flows through a burner head made of ceramic foam and ignites on its inner surface. Combustion takes place on the porous surface. The Magma burner is known as a burner with a cylindrical head. Its head consists of a stainless steel screen surrounded by a ceramic fiber layer. The fine-grained ceramic layer has aluminum silicate inclusions to achieve higher heat resistance. The gas-air mixture is supplied in a twisted form. A burner head with a hemispherical shape is the matrix burner. The surface consists of a high-alloy stainless steel wire mesh. A fuel cell is a galvanic cell that converts the chemical reaction energy of a continuously supplied fuel and an oxidant into electrical energy. The classification of the different types is based on the one hand on the electrolyte (e.g. polymer electrolyte membrane fuel cell, PEMFC) and on the other hand on the fuel used (e.g. DMFC). WO 2010/066900 A1 discloses a humidification unit for providing a fuel- and water vapor-containing carrier gas for supplying a fuel cell. The humidification unit comprises a humidification space designed to receive a fuel-containing liquid, an inlet opening into the humidification space for supplying a fuel-containing liquid, a further inlet opening into the humidification space for supplying a carrier gas in such a way that the carrier gas is in contact with the liquid in the humidification space. Furthermore, an outlet is provided for discharging the carrier gas containing gaseous fuel, a control device being provided which sets the fuel-containing liquid in the humidification chamber to a temperature below its boiling point. The control device is designed in such a way that the vapor pressures of the fuel and water vapor are regulated by adjusting the fuel concentration and the temperature of the fuel-containing liquid. WO 2015/110545 A1 discloses a fuel cell system for thermally coupled reforming with reformate processing. This system comprises a fuel cell stack having an anode inlet, an anode outlet, a cathode inlet and a cathode outlet, and a steam reforming reformer thermally coupled to the fuel cell stack for providing an anode fluid comprising reformed fuel, which is connected upstream of the anode inlet. The fuel cell stack and the reformer device are thermally coupled in such a way that the waste heat of the fuel cell stack is transferred by means of heat conduction to the reformer device and is partially used for operating the reformer device, and at least one processing device arranged between the reformer device and the anode inlet being provided for removing and/or reforming unreformed fuel and/or substances harmful to the fuel cell stack from the anode fluid, an operating temperature of the fuel cell stack being in the range between 140° C. and 230° C. In order for fuel cell stacks to reach their operating temperature, an electrical heating device is usually provided. In EP 2 706 052 A3, a method and a