DE1906553A1 - Control and regulation device for electric storage ovens - Google Patents

Description

DIPL-CHEM. DR. WERNER KOCH DR.-IMG. RICHARD GLAWE DIPL-ING; KLAUS DELFS DIPL-PHYS. DR. WALTER MOLL HAMBURG MÖNCHEN

2000 Hamburg 52 · WaltzstraB «12 · Call 892255 «000 MOnlehen 22 · LUbh« rrttra6 · 20 · Ruf 226548

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REGARDS:

POTTERTON INTERNATIONAL MMITED 84/86 Regent Streetjj London, W. 1, ""' ^lk

Control and regulation registration for electric Spelchercjjfen.

The invention relates to a temperature control device for so-called electric night storage heaters, which in are able to get one from the low-tariff electricity during Amount of heat generated during the period outside of the consumption peaks and save them as desired during peak

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POSTAL CHECK. HAMIURG Wi (B. IANK..COMMERZIANK AG. HAMMJRG, DEP.KASSE 20/120 ». TElEGR., SPECHTZIES HAMIURG.taw. SPECHTZIESMDNC

Release consumption times in the form of a stream of warm air. Such ovens essentially consist of a heat-storing mass that can be heated by a system of electrical resistance heating elements, one or more air flow channels that lead through or around the heat-storing mass, and a fan ^ which blows air through the flow-through channels to an outlet opening · Sucks. The invention is particularly applicable to so-called nozzle heating systems (dueted heating systems), in which the hot air supply of the radiator consists of a distributor chamber which is connected to a number of air ducts which in turn deliver hot air to individual Raumlüftunssschiebern, namely at a temperature of about 60 ° C. The invention can, however, also be used with individual, free-standing room storage heaters in which the air supply consists of a grill-like opening which releases the heated air in the immediate vicinity of the radiator. . · '' --- ■ _;

With both types of storage heaters, namely especially for those with air distribution ducts, means must be used to control the outlet temperature the heated air can be provided while anyway

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should be taken from the heating unit 17är.nc. The ile. ^ El no proceed that. a thermontatically controlled air valve is provided, which admixes a variable amount of cold air with the II -. ^ air flow. Thus, when the -Wärmespeichermasse is at a relatively high temperature, the valve is automatically adjusted so that there is admixed a relatively large share of cold air dec hot air and this diluted by the inside rrober limits: .to generate ;; ewünselite outlet temperature. As heat is extracted from the Speiclferpasse, the valve mixes in a progressively smaller proportion of cold air until it closes completely. When the valve is closed, the retained air makes its way through the storage mass. From this point on, the temperature of the air supplied will inevitably decrease. The effectiveness of the radiator will then get worse and worse until cheaper electricity is supplied to the radiator in order to begin a new period of heat charging.

In a known embodiment of a thermostatic controlled storage heater is a heat-sensitive Bimetal element in the hot air flow

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ordered and actuated said air control valve by means of a mechanical linkage. In one particular construction, the thermosensitive element is a helically wound bimetal element, one end of which is rigidly attached and the other end of which is attached to a first rotatable shaft. ^ The control valve consists of a rectangular flap valve which is mounted on a second shaft, which is in the tgelagert KaItluftkanal.söhwenkbä ^, pas valve changes the effective Strömüjtigsquerschnitt the cold air duct and thus the through ^ ^ rö air flowing amount. .'The first and second shaft are mechanically connected to one another in a suitable manner: »For example, by two lever arms and a connecting link which are arranged in such a way that a corresponding movement is transmitted to the control valve when the bimetal element is deflected. The arrangement is self-regulating during operation, and the position of the valve and thus the ratio of hot air to cooling air are modulated in accordance with the temperature of the air flowing past the heat-sensitive element.

Control arrangements of the type described above require energy to operate, which they the Extract hot mass from the radiator to drive a drive

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for the movements of the control valve to be supplied. The facilities described have therefore common with other facilities based on the same principle the principal disadvantage that if it together with a decreasing energy source (e.g. the decreasing heat content of the heated mass) operated, no constant output temperature can produce. This is why a radiator of this type will work under normal operating conditions a substantially constant air flow volume the actual temperature of the hot air supplied will gradually decrease. The operating behavior a control system of this type can, if desired, be modified by the fact that a a snap motion generating element is used to control the valve; but since with such Arrangements always apply the force to overcome the dead center of the snap device then undesired sudden temperature changes inevitably occur.

The invention therefore aims to overcome the above-mentioned difficulties; she sees this a fully modulating temperature control system

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before, which is derived from an external power source Servo power works to control the control valve depending on the temperature sensor and thereby an essentially constant air outflow temperature to manufacture.

Furthermore, the invention aims to create a temperature control system of the type mentioned, weife ches can be designed to be easily adjustable by hand, for example when a user briefly has a cold Heat the room with a very high air outlet temperature to then automatically switch to normal operation. .

According to the invention, there is a temperature control device for an electrical storage heater with forced air circulation and an air control valve for supply of cold air to the heated air by the heater, characterized in that a temperature sensor in the Air flow is arranged below the control valve and that one connected in series with the temperature sensor and an electrical energy source, electrically powered drive is provided to move the control valve when the temperature sensor closes the circuit closes. ·. .

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The temperature sensor preferably consists of a first, fixed electrical contact and a second, movable contact which is provided on a "bimetallic element which can be deformed by heat, one end of which is rigidly attached *

The bimetal element of the temperature sensor is preferably provided with an electrical resistance heater provided with which it is in heat-conducting connection.

In a preferred embodiment of the invention , the drive consists of an electrically heated thermal motor with a second bimetal element, one end of which is rigidly attached and the other end is connected to the control valve via a connecting link, the arrangement being such that the valve at Heating of the bimetal element is moved in one direction and when the bimetal element cools in the other direction. The valve is preferably a balanced flap valve with a rectangular flap and a centrally located axis. The drive can be designed so that the valve is either completely opened or completely closed when the bimetal element is heated

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will. In an embodiment that is preferred because of its inherent operational reliability, this is Drive arranged so that the valve is completely is open when the bimetal element is not heated. Preferably, means are provided to the Increase the heat output of the heater for a short time. this can be done by increasing the volume of the warm air emitted or by increasing the external temperature the warm air is increased *

Devices are advantageously provided in order to limit the duration of this increased heat emission and then automatically return to normal operation to pass over.

An embodiment of the invention is shown below explained on the basis of the drawings.

Fig. 1 shows a schematic longitudinal section through a heating unit. '.' ■ '-.''-

Fig. 2 shows a circuit diagram of the device,

Fig. J shows a perspective view Part of the device according to Fig. 1 ...

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• According to Fig. 1, an electrical storage heater with an air distribution system on an outer housing 1, in which three sub-units are arranged one above the other. The upper of these units, by a suitable heat-resistant casing 2 is insulated, contains the heat storage mass, the associated electrical Resistance heating elements and the air flow channels. The exact formation of these components is not essential "to the invention; in the one shown Examples are two vertical main flow channels 3 and $ provided that the air of the heat storage mass supply or * collect the heated air. The heat storage mass consists of an arrangement of grooved refractory ceramic blocks 5. These blocks together form a number of lengthways Air ducts 6, which with the two vertical Main channels 5 and 4 are in communication. The blocks are also provided with transverse grooves on their surfaces, the sioh when stacking the blocks to complement pockets 7, in which the electrical resistance and heating elements can be accommodated. It it should be emphasized that Pig. 1 is a schematic representation is and that the actual number, training and The arrangement of the blocks can look different in practice. In addition, the drawing shows the simple

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For the sake of security, various support and bearing elements have been omitted *

The middle subunit has a horizontal plate 8 with two. Openings 9 and Io is provided, which with the lower ends of the perpendicular main. channels j5 and k are aligned. A horizontally running, rectangular air duct 11 and a deflector plate 12 _: divide the sub-unit into a cold air chamber

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_; and.eiiieWärniiuftkamiiier ^ 1 ^ 1 ·. The cold air chamber 12 is in direct connection with the outside air via a louvre-like air inlet grille 15 together with a filter unit (not shown). An electrically driven centrifugal fan IG with an inlet I7 is arranged in the warm air chamber 14. The drive motor of the blower is arranged on the other side of a soldered plate 17, which for this purpose d: Lentj around the winding round the bearings ^ of the motor from the hot air. A Schwenkklappenventil19 1st at the end of Luftkanaies ll · arranged to control the flow of unerwärmterLuft Kaitiuftkammer between 15 and stöuern the hot air chamber 1 $ ^ TM An electrically heated thermal engine is adjacent the flap valve

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arranged and mechanically connected to this by a handlebar. A more detailed description of the flap valve and the associated thermal motor is given below in connection with FIG .

The lowest sub-unit of the heater consists of a box-like structure 2o, which acts as a distribution chamber serves for the warm air, which is formed from the fan 16 down through the dne in the top of the box 2o opening is supplied.

The air becomes a multitude of air openings in the room or outlets distributed, by means of a distribution system, of which for the sake of simplicity only two channels 21 and 22, which are directed opposite one another and are round in cross-section, are shown. An air temperature sensor, which is marked with the symbol TS is in the distribution chamber in close proximity to the blower outlet arranged and serves to control the position of the flap valve 19 by electrical means. The circuit and the facilities for this are in described below.

The exact construction of the air temperature sensor is for the operation of the control device, not of

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". crucial meaning. Mostly it has a ■■" - .. first fixed electrical contact and a second, movable contact, which is provided on a thermally deformable bimetallic strip, one end of which is rigidly attached * Part of the The bimetallic strip is provided with an electrically insulating cover on which an acceleration heating winding is wound to increase its temperature sensitivity. A mechanical or magnetic device of known design for generating a snap motion can also be provided to prevent arcing at the contacts as possible to suppress. ^T; "

The construction of the flap valve and the thermal motor will be described "in the following" by. Pig. 5. The valve consists of a rectangular plate 19 * at the ends of which flaps with central bores ** are provided to receive a horizontal shaft 23, the Ends are mounted in a pair of bearing brackets 24, 25 at the end of the air duct 11. The flap can be rotated through an angle of approximately 90 ° between ". one; completely, closed position (in xvelcher the upper edge of the flap against a stop26 ■

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.- ■; : ^; . β ■■ - ■■■■■ ^; ■■■■■ - ■■ '■ söhläge} and a completely open position / in which the valve is approximately parallelism * axis of the canal. The thermal motor designated as a whole by the symbol TM ₁ consists of a retaining plate 27 which is screwed onto the outside of the air duct housing 11. A mounting block 28 is attached to one end of the retaining plate and serves as an anchor for the fixed end of a bimetallic strip 29. The free end of the bimetallic strip has a bearing fork Jo and moves the Vontileklappe 19 via a connecting link are connected by a cable 34. It has been found that a dimension between 15 and 30 Wat'ccliese winding is appropriate. When electrical current flows through the resistance wire during operation, the bimetallic strip 29 is heated. Due to the deformation caused by this, its free end moves downwards and thereby closes the valve flap I9.

The electrical circuit of the temperature control device is explained below with reference to FIG. 2;

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there is the facility for heating with tarlf-: cheap electricity, which usual heating elements has other known constituents, immaterial to the invention and therefore not shown. "T

The device according to the invention is connected to the permanent electricity network (ie not to the network for the low-tariff night electricity) at 35, the live phase L with the Heizimgseiriheit; connected via a timer>6> which also contains an adjustable air thermostat with auxiliary heating (accelerated type) «Inside the heater, the live wire runs through a manually resettable overheating fuse 38 and is then connected to the conductor (N ) of the network. The first of these current paths, which is designated in Fig. 2 with A. ₃ consists of an automatic shutdown 39für the ^ blower motor from the motor windings of the Getoläses l6 and a series resistance Rj !, which serves for lowering the motor voltage. The resistor Ri can, if desired, be _{short-circuited by means of a manually operated switch S 1 in} order to increase the operating speed of the fan and; thus set an increased heating output. The scarf-

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ter S ^ is preferably in a time delay switch- ■ built in, as will be described below. This increases the length of time the • Heating output limited and then after a specified one Time automatically causes the transition to normal heating mode. ■ ■ "" ■■ "'..

The second current path, which is marked with B, is formed by the contacts of the temperature sensor TS, the heating windings of the thermal motor TM and from there to the neutral conductor N of the network. This second current path B is thus established by closing the contacts of the temperature sensor TS, whereby the pear-shaped elements of TS and TM are heated.

The work flow of the control system is described below. It is assumed that the heat storage mass is fully charged at the beginning and that the cantacts of the program clock> 5 are open. "In this state, the control valve flap I9 is fully open (ie in the horizontal position), and the contacts of TS are closed. The working cycle begins by closing the contacts of the program switch yS, and also when the thermostat 37 gives the command" heat "· the above mentioned electricity

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routes A and B closed. The fan starts to run, and air is drawn in through the inlet grille. sucks, at the same time the bimetallic strip 29 is deformed by the heating effect of the winding 33 of the thermal motor TM and the valve flap 19 begins to close accordingly. Air flows through the ducts. ^ 4 and 6, is heated and placed in the inlet of the blower

16 sucked. In addition, a certain amount of cold air is passed past the heated mass through the channel 11 % and mixed with the heated air in the chamber 14. It must be taken into account that the air flow channels in the heat storage mass have a higher flow resistance than "channel 11, so that even a relatively small opening of the flap valve brings about a noticeable cooling effect *".

The heated one flowing into the distribution chamber 2o Air acts on the temperature sensor TS. When a set air temperature is reached, open the contacts of the temperature sensor TS, so that the Current path B is interrupted. As a result, the bimetal strip 29 cools down and accordingly the flap valve I9 begins to open again,

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so that the proportion of cold air flowing in through the channel 11 is increased and the temperature in the distribution chamber is thereby reduced. As a result of this reduction in temperature, the contacts of the temperature sensor TS are closed and the current path B is restored, so that the thermal motor TM begins to close the valve flap 19 again, whereby the supply of cold air is throttled. This process is repeated at relatively short time intervals (for example on the order of 5 to ~ j> o periods per minute), and accordingly the position of the valve flap is continuously controlled in order to maintain a substantially constant temperature of the air distributed from the distribution chamber 2o .

With progressive heat extraction from the heat storage mass the valve flap slowly approaches the closed position until it finally stops the supply of cold air completely interrupted by the channel 11, so that the entire air flow makes its way through the heat storage mass takes. From this point on, the heating can no longer be influenced by the control device, see above that a gradual drop in temperature of the delivered Warm air is the result.

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Claims (1)

Pat ent ans ρ r ü c h e 1. Temperature control device for an electrical storage heater with forced air circulation and an air control valve for supplying cold air to the air heated by the heater, marked thereby-η e t that a temperature sensor (ts) in the air stream below of the control valve (19) is arranged and that a with the temperature sensor and an electrical energy source, electrically operated drive connected in series is provided to move the control valve when the Temperature sensor closes the circuit. 2. Device according to claim 1, characterized in that the temperature sensor (tm) ■ consists of a first, fixed electrical contact, a first bimetal element that can be deformed by heating, one end of which is rigidly attached, and a second, movable contact, the other at the other End of the bimetal element is provided. - 22 - BAOOBiGiNAt 90 9844/1 t ^l 4 8 5. Device according to claim 1 or 2, characterized in that the drive consists of an electrically heated thermal motor with a second bimetal element (29), one end of which is rigidly attached and the other end to the control valve (19) via a connecting link 01 ) is connected, the arrangement being made so that the valve when the second bimetal element is heated in one direction and when the bimetal element cools? is moved in the other direction * ' 4, device according to one of claims 1 to J ₃ , characterized in that the control valve is designed in a manner known per se as a rotary flap valve and has a rectangular cross-section and a centrally arranged axis of rotation. 5 device according to one of claims 1 to 4, thereby geke η η ζ eich η et, a & Q the arrangement is made in such a way that the control valve (I9) is fully open when the first bimetal element does not reach - ^: 'is hot. - * "" - '· ^; β. Device according to one of claims 1 to 5, g e k e η η ζ e i c, h η e t by devices for - 25 -. 909844/1148 Increase the heat output of the heater. 7. Device according to claim 6, characterized g e ~ k e η η ζ e i suspects that the device for reinforcement the heat emitter has a device for increasing the volume of the emitted warm air. 8. Device according to claim 7, characterized in that g e - k e η η ζ e 1 c h η e t that the device for amplifying a device for increasing the heat output the outlet temperature of the warm air. 9. Device according to claim 6, 7 or 8, g e k e η η ζ el c h η e t through a device for ■ '■. Limiting the period of time in which the heat output is increased and then allowing the heating to return to normal operation at the same time. 10. The device according to claim 7, characterized in that the forced air circulation consists of a motor-driven blower Volume of the emitted warm air has a resistance (3Λ to the resistance (R ^).;. - 24 - 800044/11 11. Device according to claim lo, geke η u - ζ e ic h η et by a Zeitverzögerungseinrlah.tiiitg for returning the switch (Sj) to the open position after a fixed period of time. Device according to Claims 2 and 6, characterized in that the device to increase the temperature of the flow has a resistor (k ^ j hem. Rj "and a switch (4o) with which the resistor is kept parallel to the contacts of the temperature sensor" TS can be. . Xj ?. Sinrlehtuns according to claim 12, characterized by a · manually operable Time-saving opportunities which the viewer Opens after a specified period of time has elapsed. 14 · device aäoh claim 2, g it leans through an electric on the first bimetal element, which is connected to this » verbuaSen is & £ nrie! & Fti & g nEOh one of claims 1 to « innseiilia * % * dai der 909S44 / 1U8 temperature sensor (ts) with a magnetic or mechanical Provided means for generating a snap movement is for quick opening and closing of the contacts. -25.- 909844/1148 -ze- L e r s e i t e