Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N5/00—Systems for controlling combustion
  • F23N5/003—Systems for controlling combustion using detectors sensitive to combustion gas properties
  • F23N5/006—Systems for controlling combustion using detectors sensitive to combustion gas properties the detector being sensitive to oxygen
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H8/00—Fluid heaters characterised by means for extracting latent heat from flue gases by means of condensation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2233/00—Ventilators
  • F23N2233/02—Ventilators in stacks
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E20/00—Combustion technologies with mitigation potential
  • Y02E20/32—Direct CO2 mitigation

Definitions

• This invention concerns in general the combustion of renewable fuels and fossil fuels, preferably for heating purposes, and relates more specificallt to a specific method for accomplishing optimized combustion and a drastic lowering of the temperature of the combustion gases and to a heating boiler for this purpose, and of the kind described in the preambles of claims 1 and 7 respectively.
• the fundamental object of the present invention is therefore to develop a method as well as a heating boiler of the kind mentioned above, which eliminate or at least minimize the above indicated problems and which satisfies the above discussed present demands as well as the anticipated future demands.
• the heating boiler 100 consists of a combustion room 1, which is made as an inner tube or shell with a circular cross section, manufactured in a high temperature and corrosion resistant material, preferably a stainless steel with a scaling temperature above about 600°C ; for heating boilers with higher effects, the scaling temperature should be higher than 850°C.
• the combustion room 1 can be surrounded by an outer shell or tube 5 manufactured from stainless steel and forming a gap 5a in relation to the inner tube 1 , whereby the space formed by the gap between the tubes is used for the circulation of water or air, with the purpose to cool the combustion room as well as to produce hot water or hot air, and by an isolated outer casing 5b.
• a burner 2 is introduced either perpendicular to but preferably tangential to the axial direction of the tube 1.
• the purpose of the latter is to achieve a turbulent flow of the combustion gases, thereby gaining an improved heat transfer to the water- or air-filled space 5a between the inner and outer shell 1 and 5 respectively and to increase the retention time for ash particles, thereby increasing the separation of these ash particles.
• the combustion room 1 may also be equipped with a spiral formed guide plate 3, indicated in the drawing, and an ash separator 4, both manufactured in a high temperature material as per above, i.e. preferably a stainless steel with a scaling temperature more than about 850°C for heating boilers with a smaller effect and around 950°C for larger heating boilers.
• the spiral formed plate 3 has such a width that it covers about half the diameter of the combustion room, as measured through the cross section thereof.
• the ash separator 4 is located at the upper end of the combustion room and has the shape of a cone, preferably a truncated cone, with its smaller cross section turned to the inner part of the combustion room.
• the total cross sectional area for combustion gases to pass through the ash separator is at least twice the cross sectional area of the condenser 7 described below.
• the hot combustion gases are transferred from the combustion room 1 to a condenser 7 through a flue duct 6 made of stainless steel or a high temperature material as per above, with a scaling temperature of more than about 700°C for smaller heating boilers and more than about 800°C for larger heating boilers.
• the condenser 7 which cools the combustion gases to a temperature less than 60°C is manufactured from a stainless steel which on one hand has a scaling temperature higher than 700°C and on the other hand has a wet corrosion resistance suited to resist the condense from the fuel giving the most corrosive conditions.
• the condenser can also be manufactured from acid proof material.
• the condenser 7 has the task of condensing the combustion gases, not only cooling them i.e. the dew point must be reached, which is also important for the efficiency of the condenser, because without condensation the effectiveness of the condenser drastically decreases.
• a welded lamella heat exchanger with a high heat transfer efficiency is used for the condenser 7.
• the lamellas are profiled. This is the ultimate design selection, since a plate heat exchanger with rubber sealing can not withstand the high temperatures. That also goes for soldered or brazed plate- and lamella heat exchangers, which soldering or brazing also can corrode. Tubular heat exchangers do technically resist the operating conditions but are too expensive.
• the condense from the condenser 7 is separated in a condense separator 8, which is equipped with a plate labyrinth and which can also be cooled to further lower the combustion gas temperature and decrease the moisture.
• the combustion gas condensation has, for the function of the heating boiler, quite decisive effects. One is that the efficiency of the heating boiler increases, which is of great importance to both the house owner and the environment, and secondly the need for a chimney is eliminated, which greatly reduces the total installation cost. Furthermore the emission of environmentally polluting combustion gases diminishes.
• the strong convective effect of the chimney is here replaced by a strong fan 9 with a net effect, corrected for the flow resistance in the outgoing tube 1 1, which is at least as large as the effect of the fan in the burner 2 used. It is a necessary condition for the function of the heating boiler, that the combustion takes place with a proper excess of air. To control that excess air is prevailing, the heating boiler is equipped with a probe 10, for direct or indirect measurement of the oxygen potential, e.g. a lamda sensor.
• a temperature sensor not shown in drawing
• a pressure sensor not shown
• a governing system also used, whereby said governing system, dependent on the values measured by the sensors, continuously controls the fan 9 and possibly the burner 2 to create optimized conditions for the combustion.
• the governing system can be locked or sealed to eliminate the risk for manipulation.
• a heating boiler designed according to the invention for use at the effect level of 10- 20 kW has a volume of only 0.25 m 3 .
• the heating boiler according to this embodiment of the invention can be manufactured to a low cost despite the fact that the cost per unit of weight of the material used is rather high.
• the reliability, due to absence of corrosion is very high even when thin walled material is used.
• optimized structure is achieved by designing the heating boiler such that the components included therein, in their shape and capacity, are carefully balanced to each other.
• the heating boiler can, in the tube 11 leading from the fan 9, be equipped with a damper 12, which through a branched tube 13 transfers a controllable part of the combustion gases back to the burner 2 for reuse, while the remaining part of the combustion gases is used in a heat exchanger 14 for preheating the fresh combustion air supplied to the burner.
• the invention concerns a heating boiler with an effect of up to a maximum of about 500 kW, suitable for the combustion of renewable fuels or fossil fuels, which is manufactured from stainless steel and high temperature materials and which can be exposed to high effect loads and may thus be designed very compact, still having a long service life and having a high degree of efficiency.
• the condenser consists of a compact and efficient, welded lamella heat exchanger which very strongly cools the combustion gases. In this way the degree of efficiency strongly increases and the need for a chimney is eliminated.
• the condense is separated in a condense separator and the cooled combustion gases or a portion thereof are then discharged from the house by means of a fan. At least one sensor governs the combustion process so that the combustion always occurs with an excess of air. No part of the heating boiler is pressurized to a pressure higher than the discharge head to the highest located radiator in the house.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Air Supply (AREA)
• Combustion Of Fluid Fuel (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=20404581

Family Applications (1)

Country Status (3)

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Citations (2)

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• 1996
  • 1996-11-13 SE SE9604138A patent/SE510235C2/sv not_active IP Right Cessation
• 1997
  • 1997-11-12 EP EP97913619A patent/EP0986721A1/de not_active Withdrawn
  • 1997-11-12 WO PCT/SE1997/001902 patent/WO1998021526A1/en not_active Ceased

Patent Citations (2)

Non-Patent Citations (1)

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