DE102009021656A1 - Instantaneous water heater and method for controlling and regulating such - Google Patents

Abstract

The invention relates to a continuous flow heater (1) for liquids, in particular for water and / or milk in beverage machines, with a heating channel (14, 14 ', 14 ") which is heated by means of a heating device (4), wherein the heating device (4) It is essential to the invention that the heating channel (14, 14 ', 14 ") is at least partially formed by the heating device (4) itself, wherein the heating device (4) in this the heating channel (14, 14', 14 ") forming region is in direct contact with the liquid to be heated.

Description

The The present invention relates to a water heater, in particular for beverage machines with the characteristics of the generic term of claim 1. Furthermore, the present invention relates a method for controlling and regulating such a flow heater with the features of the preamble of claim 10.

From the DE 10 2006 034 058 A1 is a water heater, which is used as Brühgetrankebereiter known. Such a water heater comprises an inlet, a drain and a heater whose live part is directly in contact with the liquid to be heated. The live part of the heating device is designed in particular as a bare wire heating coil, as a conductive carbon or as a PTC heating element. The conductive carbon is in an advantageous embodiment, surface, line, meandering or otherwise sprayed from the inside of the liquid-carrying body, pipe or container or injected into corresponding grooves or depressions and electrically connected. In direct contact of the live part of the heater with the liquid to be heated, the inlet and outlet of the water heater must be electrically isolated to ensure the reliability. For this purpose, the water heater between inlet and heater and between heater and drain is equipped with a respective Isolierstrecke predetermined length, which generates a necessary voltage drop due to their length and a resulting resistance, so that no voltage is present at the inlet and outlet.

adversely At this state of the art is that due to such Design large bulky designs yield and the heater large liquid flow volume due to which, in turn, increased energy consumption results if in case of non-use of the water heater cools the remaining liquid in the heater or maintained at set temperature. A large liquid flowed through Volume in the heater also requires a large Heat capacity and thereby reduces a heating and reaction rate of the water heater.

In the WO 2007/037694 A1 is a water heater for kettles, dishwashers, or the like described with a non-linear heating channel. The heating channel is formed by the fact that between a housing open towards one side, shaped as a hollow body and a closure closing this opening, designed as a heating plate, a z. B. steel or stainless steel existing two-dimensional, channel-forming structure is arranged, which directs the water along the heating plate. In this case, the two-dimensional, channel-forming structure can be formed meander-shaped or spiral-like.

adversely is the use of a designed as a lid heating plate the heating of the heating channel by one compared to the total surface of the heating channel low heating surface. Furthermore, allowed the channel walls of the channel-forming structure are not too high Otherwise, the heating surface, which is the heating channel flowing liquid heated, not sufficient is dimensioned. This limits a meaningful design of such a water heater, in terms of height. Thus, the performance of such Flow heater only by constructive extension of the device dimensions done in two directions. This inevitably leads for higher performance too very shallow but nevertheless bulky designs.

The The present invention addresses the problem of for a water heater of the generic type Kind, an improved embodiment to admit itself in particular by a compact design and by a high heating and Reaction speed distinguished.

According to the invention this task by the objects of the independent Claims solved. Advantageous embodiments are the subject of the dependent claims.

The Invention is based on the general idea of a heating channel at least partially by a heater itself to form, the Heating device in this area forming the heating channel in direct Contact with the liquid to be heated is available. In order to are both a fast heating and a high reaction speed, as well as a quick and flexible controllability of the water heater possible. In general, the heater can also the form complete heating channel. To have as much heating surface as possible based on the heating channel accommodate, a heating channel of the heater spiral, in particular even substantially in the Art of an Archimedean spiral, be formed, the Heating channel according to the invention at least partially, for example, in the form of channel walls, by the heater is formed. This design makes it very compact, flexible and realize small designs.

If the heating channel is at least partially formed as an electrically conductive flat blanked wire, a particularly large amount of heating surface is placed in a small space. Since the live part of the heater be only a certain surface load be as long as the power is not allowed to overheat, it is possible to achieve correspondingly high heating capacities in a small installation space with high flow rates by using a flat blanked wire.

There for brewing coffee or for dispensing hot water a lot of power is needed in the short term and such Instantaneous water heater, as described above, ideally no energy buffer owns, is in the short term the entire heat output in shape from electrical power to the live part to transmit the heater. This must be the network connection performance either correspond to the required heat output or, if the power consumption of the water heater over an applied grid connection power goes out, an intermediary electrical energy buffer in addition to the grid connection power provide necessary heat output.

Because directly on the liquid flowing through the heating channel Mains voltage is applied, must be a correspondingly long Isolierstrecke be realized in the water path, so that a user of the water heater can not be put under tension. This is more convenient Way in addition to the Isolierstrecken between inlet and heater and between heater and drain to the The heater facing away from the ends of the Isolierstrecken to hedge still attached a ground connection.

In Another preferred embodiment may be such Instantaneous water heater with a bare wire heater due to the fast response and low heat capacity be controlled and regulated in different ways. Already existing sensors or actuators of beverage machines can be used for new tasks, disturbances can be eliminated and target sizes easier be achieved. Thus it is possible with few sensors set the desired targets, or the existing measuring or control technology of the machines for it to use. Should, for example, a well-defined amount of drink be issued from a drinks machine and the flow rate is not clearly determined, so z. B. due to inertia by measuring the supply and Ablauftempe temperature and the known heat output be closed on the metered amount. The control, regulation and operating device of the water heater can then evaluate accordingly and control a liquid output accordingly.

Further important features and advantages of the invention will become apparent from the Subclaims, from the drawings and from the associated Description of the figures with reference to the drawings.

It it is understood that the above and the following yet to be explained features not only in each case specified combination, but also in other combinations or can be used in isolation, without the scope of the present To leave invention.

preferred Embodiments of the invention are in the drawings and will become more apparent in the following description explained, wherein the same reference numerals to the same or similar or functionally identical components relate.

It show, each schematically

1 a water heater according to the invention with running in the manner of an Archimedean spiral heating channels,

2 several heating channels with different cross sections,

3 a heating channel with two heated sides,

4 a heating channel with three heated sides,

5 a heating channel with four heated sides,

6 the heating channel with four heated sides and an optimized support wall between two heating channels.

According to the 1 includes an advantageous embodiment of a water heater 1 , a lid 2 , a one-sided open, hollow cylindrical body 3 and a heater 4 , The lid 2 of the water heater 1 has passage openings 5 on, through which for screwing to the carcass 3 screw 6 are feasible. Furthermore, the lid 2 with a feed 7 and a process 8th fitted. The unilaterally open, hollow cylindrical body 3 also includes a floor 9 and a coat 10 , which may in particular be formed in one piece, and bores 11 in the coat 10 into which the screws 6 through the passage openings 5 of the lid 2 for fixing the lid 2 on the body 3 can be screwed. An electrical connection device 12 supplies the heater 4 with electricity. For pressure protection of the water heater 1 is between the lid 2 and the body 3 optionally in a sealing groove, a sealing ring used, so that leakage of liquid or liquid vapor does not occur even at higher pressure. He According to the invention is now a heating channel 14 . 14 ' . 14 '' at least partially by the heater 4 itself is formed, the heater 4 in this the heating channel 14 . 14 ' 14 '' forming area in direct contact with the liquid to be heated. It is conceivable that at least one channel wall 15 of the heating channel 14 through the heater 4 is formed. It is thus the structure of the heating channel 14 through the heater 4 educated. In general, the heating channel 14 not as shown in the figures, must necessarily be rectangular, but may for example be round, triangular or polygonal. Accordingly, the invention also extends to a heating channel 14 in which at least one region, that is, for example, a channel wall sections 15 or a channel wall segments 15 , by the heater 4 are formed. It is by no means necessary that the channel walls 15 plan must be executed.

The heater 4 according to the 1 is spiral, preferably in the form of an Archimedean spiral, as a flat heating wire 13 formed and limited due to the spiral-like winding a heating channel 14 . 14 ' . 14 '' which also runs essentially in the manner of an Archimedean spiral. The heating channel 14 . 14 ' . 14 '' is rectangular in shape and may alternatively, for example, also meander-shaped.

Again 2 can be seen, forms the Flachheizdraht 13 in this embodiment each vertical Heizkanalwände 15 out, creating a Heizkanalwand 15 two successive turns of the formed in the form of an Archimedean spiral heating channel 14 heated. An Archimedean spiral has a winding distance 16 constant. In the case of a winding of Flachheizdrahts 13 in the form of an Archimedean spiral has the heating channel formed thereby 14 between two out of the flat heating wire 13 formed Heizkanalwänden 15 in each turn the same cross-section or the same width. But it is also possible, the Flachheizdraht 13 to wind in the form that different winding distances 16 . 16 ' . 16 '' result. This is particularly advantageous because of the adaptation of the winding spacing 16 . 16 ' . 16 '' the heating channels 14 . 14 ' . 14 '' be influenced in their cross-section. Appropriately, the winding distance is 16 . 16 ' . 16 '' from the inlet 7 coming in the direction of the process 8th because of a smaller temperature difference to the process 8th Heat transfer via a higher flow rate can be compensated. Due to the higher flow rate to the drain 8th towards the heat transfer resistance can be lowered and thus overheating of the heating channel 14 flowing liquid and the Flachheizdrahtes 13 the end 8th be avoided. According to the 2 take the turn distances 16 ' . 16 . 16 '' from the inlet 7 the end 8th in the manner described above. The flat heating wire 13 can help to better stabilize one in the soil 9 of the body 3 recessed and spiral, preferably in the manner of an Archimedean spiral, extending groove 17 be fixed and through the lid 2 of the water heater 1 in the final assembled state of the lid 2 and body 3 also be kept in its mounting position. It is possible in the lid 2 also another groove for fixing the Flachheizdrahtes 13 to mold.

The feed 7 , the sequence 8th and the electrical connection device 12 can also be different on the lid 2 or the body 3 to be appropriate. So it is conceivable that the inlet 7 in the middle of the lid 2 is located and the process 8th in the middle of the floor 9 while the connection device 12 on the coat 10 of the body 3 is installed. Such a preferred embodiment has the advantage that such a water heater 1 can simply be cascaded by the particular process 8th of the previous water heater 1 with the feed 7 of the following instantaneous water heater 1 connected, in particular, can be hidden. This creates the advantage of a modular design. It is not just a serial, but also a parallel connection of the water heater 1 conceivable, so that a high flexibility and reliability can be made possible. It is accordingly also not restricted to the fact that 7 and expiration 8th on lid 2 or ground 9 are attached. In the sense of another simplified cascading, the supply of 7 and expiration 8th in the coat 10 of the body 3 conceivable, in which case the installation site, the electrical connection device 12 is arbitrary.

As a result of a simple housing geometry in addition to plastics, which are in particular temperature resistant, also glass or ceramic materials conceivable. housing parts 2 . 3 . 7 . 8th made of glass or ceramic are particularly advantageous because they are thermally stable, are therefore outstandingly suitable as a hedge against undesired overtemperature, are pressure-stable and can be produced by a simple production technique in press or sintered form.

By the way of forming the heating channels 14 . 14 ' . 14 '' in the manner of a spiral, in particular an Archimedean spiral, such a water heater is characterized 1 by a small design and a low volume of liquid flowed through. This allows at any time a high mixing temperature, a material-friendly thermal surface load and low energy consumption, since the required hot water can be generated at the touch of a button, without the water heater 1 Energy for the stocking of consumed hot water. Another advantage of the low volume of liquid flow through the heating channel 14 is the fast and efficient way to heat the water heater 1 to descale, since even by a predetermined flow direction descaling succeeds more advantageous.

According to 3 can the flat heating wire 13 the heating channel walls 15 of the heating channel 14 form. An advantage of this is, as already stated above, the heating of the heating channel 14 flowing liquid through the Heizkanalwände 15 after two pages.

In a further expedient embodiment according to the 4 can individual Flachheizdrahtabschnitte 18 . 19 forming channel walls. At very small pitches 16 this embodiment is less well suited, since due to the small pitch of windings 16 the Flachheizdrahtabschnitte 19 of the heating channel 14 only a small contribution to the heating of the heating channel 14 through flowing liquid makes. This also applies analogously to an expedient embodiment according to FIG 5 , at the four walls of the heating channel 14 for heating the heating channel 14 contribute through flowing fluid. In this embodiment, it is conceivable that also on the lid 2 in spiral form a Flachheizdrahtabschnitt 20 is attached, leaving a completely through the heater 4 , or its Flachheizdrahtabschnitte 18 . 19 . 20 heated heating channel 14 arises. Similarly, the embodiment according to FIG 6 formed, in which case the channel wall 15 is formed as a heat-conducting support wall for Flachheizdrahtabschnitte.

As with a water heater 1 with an electric heater 4 in which the live part of the heater 4 directly with the heating channel 14 flowing liquid comes into contact with 7 and expiration 8th a supply and Ablaufisoliereinrichtung, in particular designed as Isolierstrecke plan, so that the heater 4 and thus also the water heater 1 is electrically insulated from the outside. In addition, it makes sense to connect such an electrical insulation device to 7 and expiration 8th to be protected by a ground connection.

It is also advantageous to have such a water heater 1 comprising a control and regulating device, in particular having a programmable logic circuit, such as a microcontroller, a data memory for storing sequence programs, device parameters and program parameters, a data interface device, as well as an output device and an input device for ease of operation. By such a control, regulation and operating device or by an analog integrated in the beverage vending control, regulation and operating device, it is possible by means of the existing sensors of the water heater 1 or the surrounding components at least one parameter, such. B. an inlet temperature of the liquids in the water heater 1 , an outlet temperature of the liquids from the water heater 1 to determine a volume flow of the liquids, a delivered volume, the power consumed by the network, or a sampling time, and to calculate at least one further parameter from the determined or known parameters. The aim is to set a desired target size with as few sensors as possible, or the existing measurement and control technology of the surrounding components or the water heater 1 for use.

In a preferred embodiment is the volume flow known and especially constant. The inlet temperature is measured and the power absorbed by the network by the user varied. In this case, the outlet temperature can be calculated from the volume flow, the inlet temperature and the electrical absorbed from the mains Performance are calculated and the thus determined outlet temperature over the output device will be displayed, giving the user the option is given as long as the power to vary until the desired Outlet temperature is reached.

Analogous For this purpose, the outlet temperature at a known power, measured Inlet temperature and variation of the volume flow by the user from the volume flow of the inlet temperature and from the network recorded electrical power can be calculated, in turn the so determined outlet temperature displayed on the output device be given to the user and the opportunity as long as the volume flow to vary until the desired Outlet temperature is reached.

It again it is also possible to measure the volume flow, to measure the outlet temperature and those taken from the grid To let the performance vary by the user until the from the volume flow of the inlet temperature and from the network absorbed power calculated outlet temperature over the output device is displayed, the desired Setpoint has reached.

This is also conceivable when measuring the inlet temperature and the outlet temperature and varying the power absorbed by the network, in which case the outlet temperature can be displayed via an output device and the power absorbed by the network is varied by the user until a desired setpoint of the outlet temperature is reached.

Also at known volume flow, measurement of the outlet temperature and Variation of power absorbed by the network by the user can the power consumed by the grid be varied as long as to the exit temperature indicated by the dispensing direction has reached the setpoint.

Now it is natural in a preferred embodiment also possible by the user, the outlet temperature enter into the control, regulation and operating device and the control, regulation and operating device as long as at least to vary a variable parameter until the desired one Setpoint of the outlet temperature is reached. Thus, the adjustment the outlet temperature is not made manually, but automated after setting the desired outlet temperature performed by the control, regulation and control device.

In a further expedient embodiment, the volume flow, the inlet temperature and the outlet temperature are measured, and the power absorbed by the network is calculated from the volume flow of the inlet temperature and the outlet temperature. This calculated power taken from the grid allows conclusions to be drawn about voltage differences or defects in the heating device 4 close and it is possible due to the inertial behavior of the water heater 1 to determine a degree of calcification of the heating device in the start-up phase.

In Another embodiment is taken from the network Performance known, inlet temperature and outlet temperature are measured, the extraction time is determined and an average Volume flow is calculated from the specific heat capacity, the density of the liquids, as well as the inlet temperature, Outlet temperature and the power consumed from the grid, to due to the volume delivered an output of the liquid to end when the desired volume is reached.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102006034058 A1 [0002]
• - WO 2007/037694 A1 [0004]

Claims (18)

Instantaneous water heater ( 1 ) for liquids, in particular for water and / or milk in beverage machines, with a heating channel ( 14 . 14 ' . 14 '' ) heated by a heating device ( 4 ) is heated, wherein the heating device ( 4 ) comprises an electrically conductive bare wire, characterized in that the heating channel ( 14 . 14 ' . 14 '' ) at least in regions by the heating device ( 4 ) itself is formed, wherein the heating device ( 4 ) in this the heating channel ( 14 . 14 ' 14 '' ) forming region is in direct contact with the liquid to be heated. Instantaneous water heater according to claim 1, characterized in that - the heating channel ( 14 . 14 ' . 14 '' ) is rectangular and spirally, in particular in the manner of an Archimedean spiral runs, or - that the heating channel ( 14 . 14 ' . 14 '' ) is rectangular and runs meandering. Instantaneous water heater according to claim 1, characterized in that the heating channel ( 14 . 14 ' . 14 '' ) has a round shape and at least in one area by the heating device ( 4 ) is formed. Flow heater according to one of claims 1 to 3, characterized in that a housing of the water heater ( 1 ) comprises at least the following housing sections, a cover ( 2 ) and a unilaterally open, hollow cylindrical body ( 3 ), comprising a floor ( 9 ) and a coat ( 10 ), in particular integrally formed, wherein at least one housing section ( 2 . 3 . 9 . 10 ) made of temperature-resistant and / or pressure-resistant material, in particular of metal, plastic, glass or ceramic. Flow heater according to one of the preceding claims, characterized in that a Zulaufisoliereinrichtung and a Ablaufisoliereinrichtung are provided which the heating device ( 4 ) electrically insulate to the outside. Instantaneous water heater according to one of the preceding claims, characterized in that the instantaneous water heater ( 1 ) an electrical energy storage device, such. B. a capacitor or a double-layer capacitor, which has a power consumption of the water heater ( 1 ) is compensated beyond an applied grid connection power. Instantaneous water heater according to one of the preceding claims, characterized in that the instantaneous water heater ( 1 ) is designed such that the liquids flowing through can also be heated beyond a boiling temperature thereof. Instantaneous water heater according to one of the preceding claims, characterized in that the instantaneous water heater ( 1 ) is equipped with a sensor device having at least one sensor from the following group, - a temperature sensor for determining an inlet and / or outlet temperature, - a flow sensor for determining a volume flow of the liquids flowing through, - a sensor for detecting a recorded from the network Power. Instantaneous water heater according to one of the preceding claims, characterized in that the instantaneous water heater ( 1 ) is equipped with a control and regulating device having at least one component from the following group, - a programmable logic circuit, such. As a microcontroller for data processing and control / - at least one data memory for storing flow programs, device parameters and program parameters, - a data interface device, - an output device for informing a user, - an input device for operating the control, and operating device. Method for operating, controlling and regulating a continuous flow heater ( 1 ) according to one of the preceding claims, in which at least one of the following parameters is measured or known and at least one of the following parameters can be set, - an inlet temperature of the liquids into the instantaneous water heater ( 1 ), - an outlet temperature of the liquids from the instantaneous water heater ( 1 ), - a volumetric flow of liquids, - a delivered volume, - the power absorbed by the network, - an extraction time. A method according to claim 10, characterized in that - the volume flow is known and in particular constant, - the inlet temperature is measured, - the power absorbed by the network is varied by the user, - the outlet temperature from the volume flow, the inlet temperature and from the Net recorded, electrical power is calculated by the control, regulation and control device, - the thus determined outlet temperature is displayed on the output device and - The user varies the power until the desired outlet temperature is reached. Method according to claim 10, characterized, that - the performance is known - the Inlet temperature is measured, - the volume flow is varied by the user, - the outlet temperature from the volume flow, the inlet temperature and from the network absorbed electrical power by the control, regulation and and operating device is calculated, - the so determined Outlet temperature displayed via the output device will and - the user varies the volume flow until the desired outlet temperature is reached. Method according to claim 10, characterized, that - the volume flow is measured, - the Outlet temperature is measured, - those from the network the power consumed by the user is varied, - the Outlet temperature from the volume flow, the inlet temperature and the power consumed from the grid by the control, Control and operating device is calculated, - the so determined outlet temperature on the output device is displayed and - the user as long as from the Power absorbed varies until the desired Outlet temperature is reached. Method according to claim 10, characterized, that - the inlet temperature is measured, - the Outlet temperature is measured, - those from the network the power consumed by the user is varied, - the Outlet temperature displayed via the output device will and - The user as long as taken from the network Power varies until the desired outlet temperature is reached. Method according to claim 10, characterized, that - the volume flow is known, - the Outlet temperature is measured, - those from the network the power consumed by the user is varied, - the Outlet temperature displayed via the output device will and - The user as long as taken from the network Power varies until the desired outlet temperature is reached. Method according to claim 10, characterized, that - the volume flow is measured, - the Inlet temperature is measured, - the outlet temperature is measured - the power absorbed by the network from the volume flow, the inlet temperature and the outlet temperature calculated by the control, regulation and operating device is taken out of the network because of the so determined Power to voltage differences or defects in the heater and / or due to the inertial behavior in a start-up phase to conclude a degree of calcification of the heater. Method according to claim 10, characterized, that - the power consumed by the network is known, - the Inlet temperature is measured, - the outlet temperature is measured - the sampling duration is determined, - one average volume flow from the specific heat capacity and the density of the liquids and the inlet temperature, Exit temperature and the power absorbed from the network calculated by the control, regulation and operating device is due to by the average flow rate Volume delivered an output of the liquid to end. Method according to one of claims 10 to 17, characterized in that at least one of the measured or known parameter is displayed by the output device and / or at least one such measured or known parameter of the Control, regulation and operating device is used to at least one target parameter on the variation of at least a variable parameter to a desired value adjust.