US3354945A - Tube heat exchanger with anti-freeze thermostat - Google Patents

Tube heat exchanger with anti-freeze thermostat Download PDF

Info

Publication number
US3354945A
US3354945A US626817A US62681767A US3354945A US 3354945 A US3354945 A US 3354945A US 626817 A US626817 A US 626817A US 62681767 A US62681767 A US 62681767A US 3354945 A US3354945 A US 3354945A
Authority
US
United States
Prior art keywords
heat exchanger
tube
water
outdoor air
thermostat
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US626817A
Other languages
English (en)
Inventor
Grudeborn Lars-Owe
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Svenska Flaktfabriken AB
Original Assignee
Svenska Flaktfabriken AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Svenska Flaktfabriken AB filed Critical Svenska Flaktfabriken AB
Application granted granted Critical
Publication of US3354945A publication Critical patent/US3354945A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D23/00—Control of temperature
    • G05D23/19—Control of temperature characterised by the use of electric means
    • G05D23/275—Control of temperature characterised by the use of electric means with sensing element expanding, contracting, or fusing in response to changes of temperature
    • 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
    • F24D19/00—Details
    • F24D19/008—Details related to central heating radiators
    • F24D19/0085—Fresh air entries for air entering the room to be heated by the radiator
    • 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
    • F24D19/00—Details
    • F24D19/0095—Devices for preventing damage by freezing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/89—Arrangement or mounting of control or safety devices

Definitions

  • the present invention relates to tube heat exchangers for heating outdoor air by means of hot Water and more particularly to a device for preventing freezing of the water in the exchanger.
  • Heat exchangers used for heating outdoor air by means of hot water are subject to freezing in many climatic zones in winter.
  • heat exchangers In order to eliminate the risk of freezing, heat exchangers have been equipped with an antifreeze thermostat which operates to reduce the flow of outside air.
  • the sensing body of the thermostat is placed in the path of the air in close contact with the tubes of the heat exchanger 'or is placed in the return pipe for water outside the heat exchanger.
  • the sensing body senses primarily a temperature which falls between the temperatures of the outdoor air and that of the water (i.e., a temperature below that of the water), and the sensing body must therefore be located on the rear side of the heat exchanger in the path of flow of the air so as not to give an impulse before a real risk of freezing occurs.
  • the sensing body senses primarily a temperature which falls between the temperatures of the outdoor air and that of the water (i.e., a temperature below that of the water)
  • the sensing body must therefore be located on the rear side of the heat exchanger in the path of flow of the air so as not to give an impulse before a real risk of freezing occurs.
  • the tute heat exchanger may be damaged Iby freezing if the ow of water through the heat exchanger is interrupted, since the sensing body cannot possibly sense the temperature drop in the water which remains in the heat exchanger.
  • the present invention eliminates the drawbacks of the aforementioned arrangements by providing a thermostat having a sensing body mounted in the heat exchanger itself so as to be sensitive to the water flow within the active part of the heat exchanger.
  • the sensing body of the thermostat is made with a cross section which is sufficiently small relative to the cross sectional area of the tube of the heat exchanger so that the free ow area for the Water, in the area where the sensing element is mounted, is small so as not to reduce the free ilow area in that tube more than necessary, to insure that the volumetric rate of Water flow in the tube having the sensing element is less than in the remaining tubes of the heat exchanger.
  • FIG. 1 is a fragmentary perspective view of a heat exchanger embodying an anti-freeze thermostat in accordance with the present invention
  • FIG. 2 is a diagrammatic view illustrating the preferred environment for the heat exchanger of FIG. 1 in accordance with the present invention
  • the tube heat exchanger comprises a casing 1 having a series of finned tubes 2 connected at one side to a common header 3 which is connected with a return pipe 4 for the hot water flowing through the heat exchanger.
  • a similar header (not shown) is connected to the tubes 2 at the other side for supplying hot water to the tubes from a hot water supply pipe 11 (FIG. 2).
  • the casing is mounted in a duct 12 adapted to receive outside air, for example through a conduit 13 having a damper 14 therein. Secondary room air may be supplied to the duct 12 by means of a conduit 15 having a similar damper 16 therein.
  • the outside air from the duct 12 is caused to flow through the heat exchanger 1 by means of a blower 17 having suitable control means 18.
  • the dampers 14 and 16 may be controlled automatically by a controller 19 and normally the dampers are set to provide full ilow through the conduit 13 and minimum ow through the conaduit 15, so as to supply maximum outside air to the warmed-air room inlet 20.
  • a thermostat which is responsive to the temperature of the water flowing through the tubes of the heat exchanger close to and upstream of the water return pipe 4.
  • a thermostat 7 is provided having a capillary tube 6 connected to a sensing element 5 which is positioned in the tube 2 which is closest to the return duct 4.
  • the cross sectional area of the sensing element 5 relative to the cross sectional area of the tube Z is small so as not to reduce the free flow area for the water in the tube more than necessary, to insure that the volumetric flow in the tube having the sensing element 5 is less than the ow in the remaining tubes of the heat exchanger.
  • the Water in the tube having the sensing element therein will be cooled to a greater extent than the water in the remaining tubes and will therefore provide a proper reading in the thermostat 7 to prevent freezing in any of the tubes of the heat exchanger.
  • the thermostat 7, when its reading indicates a freeze is likely to occur is connected to the controls 18 and 19, as desired, either to reduce the total ow of cold air through the exchanger, or to introduce warmer air into the flow of cold air so as to moderate or reduce the cooling effect of the air flow upon the water in the tube heat exchanger. It is preferred to reduce the cooling effect of the outdoor air rather than to increase the heating effect of the water since the water is normally supplied from a remote source which supplies hot water to a plurality of locations and which is not readily susceptible to regulation of its heating effect.
  • a tubular heat exchanger for heating outdoor air having at least one tube connected at one end to a remote source supplying heated water and at the other end to a return pipe, an inlet for introducing outside air ⁇ to said heat exchanger and an outlet for discharging the 3 4 operating said control means including a sensing body in the volumetric flow in said tube is less than in the remainsaifl tube itl. the flow-path of the Water .C1956 t9 and infubesofsad heatexchange l upstream of the Water return pipe.
  • a tubular heat exchanger according to claim 1 in- References Cited cluding a plurality of tubes connected in parallel between 5 UNITED STATES PATENTS common headers, said sensing element being mounted in 1,942,559 1/1934 Lithman 219-341 one of said tubes, the cross sectional area of said sensing 2,190,232 2/ 1950 Fry 16S-39 body relative to the cross sectional area of said tube being small so as not to reduce the free flow area for the ROBERT A O LEARY Pnmary Examiner' water in said tube more than necessary, to insure that 10 CHARLES SUKALO, Examiner.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Thermal Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
US626817A 1964-05-11 1967-03-29 Tube heat exchanger with anti-freeze thermostat Expired - Lifetime US3354945A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE5707/64A SE313064B (xx) 1964-05-11 1964-05-11

Publications (1)

Publication Number Publication Date
US3354945A true US3354945A (en) 1967-11-28

Family

ID=20267042

Family Applications (1)

Application Number Title Priority Date Filing Date
US626817A Expired - Lifetime US3354945A (en) 1964-05-11 1967-03-29 Tube heat exchanger with anti-freeze thermostat

Country Status (7)

Country Link
US (1) US3354945A (xx)
BE (1) BE663767A (xx)
DK (1) DK134574B (xx)
FI (1) FI48014B (xx)
GB (1) GB1102277A (xx)
NL (1) NL6505884A (xx)
SE (1) SE313064B (xx)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3980129A (en) * 1973-12-04 1976-09-14 Knut Bergdahl Heat exchange in ventilation installation
US4109705A (en) * 1973-12-04 1978-08-29 Knut Bergdahl Heat exchange in ventilation installation
DE4313210A1 (de) * 1992-04-24 1993-10-28 Ingersoll Rand Co Nachkühler für einen Verdichter für niedrige Temperaturen

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1942559A (en) * 1932-10-19 1934-01-09 Lithman Leopold Radiator
US2190232A (en) * 1937-03-17 1940-02-13 Bireley S Inc Temperature control means

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1942559A (en) * 1932-10-19 1934-01-09 Lithman Leopold Radiator
US2190232A (en) * 1937-03-17 1940-02-13 Bireley S Inc Temperature control means

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3980129A (en) * 1973-12-04 1976-09-14 Knut Bergdahl Heat exchange in ventilation installation
US4109705A (en) * 1973-12-04 1978-08-29 Knut Bergdahl Heat exchange in ventilation installation
DE4313210A1 (de) * 1992-04-24 1993-10-28 Ingersoll Rand Co Nachkühler für einen Verdichter für niedrige Temperaturen
US5284202A (en) * 1992-04-24 1994-02-08 Ingersoll-Rand Company Compressor aftercooler apparatus for use in low temperature operations, and method of use
DE4313210C2 (de) * 1992-04-24 1998-01-15 Ingersoll Rand Co Nachkühler für einen Verdichter für niedrige Temperaturen

Also Published As

Publication number Publication date
FI48014B (xx) 1974-01-31
SE313064B (xx) 1969-08-04
BE663767A (xx) 1965-09-01
GB1102277A (en) 1968-02-07
DK134574B (da) 1976-11-29
NL6505884A (xx) 1965-11-12

Similar Documents

Publication Publication Date Title
US6612267B1 (en) Combined heating and hot water system
US10551078B2 (en) Methods and apparatus for latent heat extraction
US4187687A (en) System for utilizing solar energy and ambient air in air conditioners during the heating mode
US6032868A (en) Combined hot water and space heater
US5588591A (en) Heat dissipation unit
US4171621A (en) Freeze protection device in heat pump system
US3354945A (en) Tube heat exchanger with anti-freeze thermostat
US3627033A (en) Air heaters with enclosing dampers for protection against freezing
US3833170A (en) Single unit air-water heating appliance
USRE22685E (en) Valve arrangement
JPS5837446A (ja) 空気加熱装置
GB1479837A (en) Heat exchanger and heating installations incorporating such an exchanger
US4147206A (en) Semi-active temperature control for heat pipe heat recovery units
US4090492A (en) Forced air furnace with liquid heat exchanger
US3472313A (en) Central heating and cooling system
US2263074A (en) Unit heater and air conditioner
US2220754A (en) Steam heating system with steam powered air circulation means
US4535934A (en) Hot water heat distributor
US2588723A (en) Method of converting air conditioning systems
US3166121A (en) Space heat exchange unit
RU2145691C1 (ru) Отопительный конвектор
US3543731A (en) High velocity water heater
US2079453A (en) Heating or cooling system
US3655127A (en) Heating system
GB1073776A (en) Air conditioning systems and units