Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
  • F28D21/0001—Recuperative heat exchangers
  • F28D21/0003—Recuperative heat exchangers the heat being recuperated from exhaust gases
  • F28D21/0005—Recuperative heat exchangers the heat being recuperated from exhaust gases for domestic or space-heating systems
  • F28D21/0007—Water heaters
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D12/00—Other central heating systems
  • F24D12/02—Other central heating systems having more than one heat source
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D3/00—Hot-water central heating systems
  • F24D3/08—Hot-water central heating systems in combination with systems for domestic hot-water supply
• • 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
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D2200/00—Heat sources or energy sources
  • F24D2200/16—Waste heat
  • F24D2200/18—Flue gas recuperation
• • 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]

Definitions

• a Heating System with a Condensing Boiler.
• the present invention relates to a heating system with a condensing boiler comprising a number of mainly uniform smoke gas/water heat exchanger sec ⁇ tions, each provided with an internal flue and a sur- rounding water jacket, said sections being series- coupled with respect to the smoke gas flow from a burner unit in connection with a first section to a smoke gas outlet with induced draught in connection with a last section.
• a heating system is known, in which a number of horizontally disposed parallel heat exchanger sections are superposed. The smoke gas flows through the sections in series in their longitudinal direction and with opposed flow direc- tions in adjacent sections, while the water flow takes place in the upward direction transversely to the longitudinal direction of the sections.
• the efficiency of the system will be limited by the fact that the highest water temperature occurs in the uppermost section where the smoke gas temperature is lowest. As the smoke gas must then have a discharge temperature that is higher than the desired supply water temperature for the radiator system, a complete utilization of the heat content of the smoke gas for heating the supply water for the radiator system cannot be obtained.
• a consider ⁇ ably improved utilization of the heat content of the smoke gas and thereby an optimum efficiency is obtained for a heating system with a condensing- boiler in that the heat exchanger, sections are disposed vertically in juxtaposed relationship, the smoke gas discharge being connected with the upper end of the last section, and in that the sections are moreover series-coupled with respect to the water flow through said water jackets with an inlet for return water from a radiator circuit at the upper end of the last section and an outlet for supply water to the radiator circuit at the first sec ⁇ tion, condensate discharge means being provided in connection with transitional flues connecting the lower ends of adjacent sections.
• the boiler structure is simple so that the sections can be produced at comparatively low costs and with good possibilities of cleaning and maintenance, inasmuch as the flues in the individual sections may be connected at their upper ends through detachable caps. Moreover, due to the transitional flues between the lower ends of some of the sections an effective discharge of condensate is obtained.
• a hot water supply system is further connected with the boiler an additionally increased efficiency is obtained for the whole heating system including the radiator circuit and the hot water supply system, in that a cold water inlet for the hot water supply system is coupled to water pre-heating means positioned in the water jacket. of the last section and having its water discharge con ⁇ nected with a water/water heat exchanger heated by the supply water to the radiator circuit.
• such an aggregate heating system may comprise a control unit to actuate valve members so as to obtain during summer operation a tap water temperature for the hot water supply that is higher than the temperature of the supply water from the first boiler section.
• control unit that may comprise a microprocessor is capable of controlling the burner unit in dependence of a program caring for day and night • control of the supply water temperature and for survey ⁇ ing the smoke gas temperature, the supply water temper ⁇ ature, the return water-temperature, the fuel consump- tion and the condensate discharge.
• Fig. 1 is a schematical diagram of an embodiment of a heating system according to the invention.
• Fig. 2 is a perspective view of a modified design to more fully illustrate details of a practically suitable construction
• Figs. 3 and 4 are diagrams of two different em- bodiments of a hot water supply system in connection with the heating system.
• the heating system schematically shown in Fig. 1 has a boiler comprising a "number of vertically dis ⁇ posed sections 1 to 5 each of which is formed as a smoke gas/water heat exchanger with an internal tubular flue 6 from which an effective heat transfer is effected through a wall 7 to a surrounding water jacket 8 of annular cross-section.
• the first boiler section 1 is connected at its lower end with a burner unit for a liquid or gaseous fuel such as oil or natural gas.
• the burner unit 9 which is not shown in detail may be of conventional design and provided with fuel pre-, heating means as known in the art to reduce fuel consump ⁇ tion.
• the sections 1 to 5 are series-coupled both with respect to the smoke gas flow effected from burner unit 9 through the first section 1 to the upper end of the flue 6 in the heat exchanger section 2 and from there further on through' the flues in sections 3, 4 and 5 to a smoke gas discharge 10 connected with the upper end of the section 5, an induced draught fan 11 being mounted in said discharge, and with respect to the water flow effected from an inlet 12 for return water from a radiator circuit not shown, connected with the upper end of the section 5 through the annular water jackets 7 in sections 5, 4, 3, 2 , and 1 in said order, of succession on to a discharge 13 for supply water to the radiator circuit connected with the water jacket in section 1.
• An expansion tank 14 is further connected with the water jacket in section 1.
• the heat transfer sur ⁇ face between the flue and the water jacket has been enhanced by forming the heat transfer wall 7 to be wave-shaped such as known from US-A-2,587,530.
• rod-like cylindrical displacement members 15 may be arranged in the flues of the sections coaxially with the tube walls 7, such as known from DE-A-22 27 070.
• condensate deposits which is collected in the transitional flues 16 and 17 connecting the lower ends of the flues in adjacent sections 1 to 3 and 4 to 5, respectively, and is removed through condensate outlets 18.
• a water connecting tube 26 extending between the upper ends of the sections 1 and 5 serves control purposes with respect to a hot water supply system associated with the heating system, as further explained in the following.
• Heating coils 27 and 28 arranged in the water jackets of the heat exchanger sections 5 and 1 form part of a design of such a hot water supply system described in the following with reference to Fig. 4.
• a box 29 beneath the heat exchanger sections accommodates a neutralization unit for the condensate discharged through the outlets 18.
• the neutralization unit may for instance comprise an exchangeable bag containing crushed marble receiving the condensate through a water seal not shown. The condensate thus percolates through the crushed marble, thereby being neutralized, e.g. so that its pH-value which generally is about 2,5 increases to about 7.
• the box 28 is pro ⁇ vided with a detachable cover 29 to be used when replacing the neutralization bag.
• the cold water inlet 31 thereof is coupled to water pre-heating means 32 arranged in the water jacket of the last heat exchanger section 5 in the form of a heating coil, e.g. designed as shown at 27 in Fig. 2.
• the water discharge 33 from the water pre-heating means 32 is connected with a water/water heat exchanger heated by the supply water to the radiator circuit dis- charged from the section 1.
• this water/ water heat exchanger comprises a hot water tank 34 having a heating coil 35, the water inlet 36 of which is coupled to the discharge 13 for supply water from the 5 section 1 through a controlled valve member 37, by means of which the. water discharge 13 may be coupled either to the radiator system or to the heating coil 35.
• the water discharge 38 from the heating coil 35 is connected with another controlled valve member 39, 10 by means of which it can be coupled either to the radiator circuit through a communication 40 or to the return water inlet 12 at the water jacket in the heat exchanger section 5 through a by-pass connection 41.
• the valve members 37 and 39 may be three-way •15 magnet valves controlled from a central control unit 51, which for instance may include a microprocessor, in dependence ori the temperature of the supply water for the radiator system at water discharge 13 measured by a temperature measuring device 42 and the temperature... 20 of the tap water at the water discharge 44 from the water tank 34 to the hot water supply system.' measured by a temperature measuring device 43.
• a desired tap water temperature for instance between 35 and 60 C, may be adjusted.
• the supply water is caused by valve 37 to by-pass the hot water tank 34 and flow directly to the radiator sy ⁇ stem. If, on the contrary, the tap water temperature 30 measured by the measuring device 43 is lower than the desired temperature, whereas the supply water tempera ⁇ ture at the measuring device 42 exceeds the desired tap water temperature, the supply water is caused by valves 37 and 39 to pass through the hot water tank 34 and from 35 there further on to the radiator system.
• the control unit 51 actuates, however, the valve 39 i such a manner that the supply water subsequent to having passed through the heating coil 35 is conducted through the by-pass conduit 41 to the return water inlet 12 of the last heat exchanger section 5.
• a direct recircula- tion of the supply water through the boiler is thereby established and the control unit 51 which also controls the burner unit 9 is adapted or programmed so as to maintain the burner unit in a state of full output in this situation till the tap water has attained the desired temperature.
• the water/water heat exchanger con- : nected with the water, discharge .33' of the water pre- heater 32' is constituted by a heating coil 45 located in the water jacket of the section 1 and having its water discharge 46 connected with the hot water supply system.
• the tap water temperature measured by a temperature measuring device 47 is in this case controlled by mixing the water passed through the heating coil 45 with cold water supplied from the cold water inlet 31 ' of the water pre-heater 32 through a controlled valve member 48.
• the water discharge 1.3 for the supply water from the water jacket of the transitional section is connected with another controlled valve member 49 by means of which the supply water may be coupled either directly to the radiator system or through a by-pass connection 50 to the return water inlet 12 for the water jacket in the last heat exchanger section 5.
• this allows establishment of a direct recirculation of the supply water through the boiler to be used for instance during summer operation or, in the embodiment shown in Fig. 4, also in case of peak load, in which case the radiator circuit is switched off and only tap water heating is effected.
• the control unit 51 and 51 * , respectively, for the valve members 37, 39 and 48, 49, respectively, may further be connected with a surveying device in the form of a pH-measuring device 52 and 52', respect ⁇ ively, for controlling the acidity of the condensate passing through the neutralization unit in Fig. 2 and with an alarm device 53 and 53', respectively, so as to produce an alarm signal when the pH-value falls below a prescribed threshold value, for instance 6, as a warning that the aforementioned neutralization bag is to be replaced.
• a surveying device in the form of a pH-measuring device 52 and 52', respect ⁇ ively, for controlling the acidity of the condensate passing through the neutralization unit in Fig. 2 and with an alarm device 53 and 53', respectively, so as to produce an alarm signal when the pH-value falls below a prescribed threshold value, for instance 6, as a warning that the aforementioned neutralization bag is to be replaced.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Water Supply & Treatment (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
• Control Of Steam Boilers And Waste-Gas Boilers (AREA)
• Steam Or Hot-Water Central Heating Systems (AREA)
• Instantaneous Water Boilers, Portable Hot-Water Supply Apparatuses, And Control Of Portable Hot-Water Supply Apparatuses (AREA)

Applications Claiming Priority (4)

Publications (1)

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ID=26063164

Family Applications (1)

Country Status (6)

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• 1982
  • 1982-10-04 DK DK439582A patent/DK439582A/da unknown
  • 1982-12-20 WO PCT/DK1982/000113 patent/WO1983002493A1/en not_active Application Discontinuation
  • 1982-12-20 JP JP50018282A patent/JPS59500143A/ja active Pending
  • 1982-12-20 EP EP83900022A patent/EP0098272A1/en not_active Withdrawn
• 1983
  • 1983-09-05 NO NO833172A patent/NO833172L/no unknown
  • 1983-09-05 FI FI833159A patent/FI833159A/fi not_active Application Discontinuation

Non-Patent Citations (1)

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