CN1210582A - Heating apparatus and method for operation thereof - Google Patents

Abstract

The invention relates to an apparatus for heating fluid, comprising: first supply means (2) for supplying fuel; second supply means (4) for supplying oxidizing agent; burner means (5) for combusting fuel and oxidizing agents after mixing thereof; and a first heat exchanger (8) to be heated by flue gases of the burner means (5) and arranged helically round the burner means (5).

Description

Heating device and its method of operation

Heating devices with improved efficiency (IE) and high efficiency (HE) are widely used in the Netherlands and elsewhere for the heating of residential houses and other housing areas. For many dwellings it is important that these heating devices be as compact as possible and that they are not so complex that they require regular and costly maintenance.

These existing heating devices have many disadvantages, the most important of which are: the large size of the devices, they are difficult to fit in a cabinet; the emission of CO and NOx and the loss of efficiency associated with this, for example, there are considerable temperature difference exists.

The invention provides a device for heating fluid, which comprises

-- the first supply equipment for supplying fuel;

-- The second supply equipment is used to provide oxidizing agent;

-- burner equipment for combusting the fuel and oxidizer after mixing them; and

--A first heat exchanger, which is heated by the exhaust gas of the burner, and is arranged in a helical shape around the burner equipment.

The heating device obtained according to the invention can be made very compact with reduced emissions and efficiency losses.

The preferred embodiment of this arrangement utilizes precise directing of the flow of combustion products along the heat exchanger, resulting in further efficiency improvements and reduced emissions of undesired combustion products.

An open jacket is preferably arranged around the helical heat exchanger in order to obtain a good heat exchange between the combustion gases and the heat exchanger tubes. These openings can be circular or slot-shaped, and they are preferably arranged behind the helically running heat exchanger tubes. The jacket can also be formed from wound metal strips or bent plates, leaving openings between these strips or plates.

In a device known as a combination, it consists of an insulating cylinder or container of relatively small size, from whose interior hot water is readily available. A compact combined unit with 22-24 kW power should be able to get 6 liters per minute of 60°C hot water from this insulated storage drum or tank. However, in the existing combined equipment, it is found that the time of supplying water at 60° C. is not long during use, and then the temperature of the hot water in the water pipe decreases, and a constant value above 60° C. is only reached after, for example, one minute. This is especially the case when the heating unit is not used or is used only infrequently to heat liquid in pipes and radiators in residential heating systems (called modulating operation). While the preferred embodiment of the present invention has such a water tank, another preferred embodiment has a heat exchanger that takes up little space.

The present invention further provides an apparatus having a water tank for temporarily storing hot water, wherein the water tank includes a second heat exchanger cooperating with the first heat exchanger.

The first heat exchanger is preferably further provided with an inner tube and an outer tube, and the pipeline water is further heated in the inner tube.

The device according to the invention is also preferably provided with a third heat exchanger arranged at the heated exhaust gas discharge pipe for preheating of the pipe water.

The preferred embodiment with a water tank preferably has a water pump unit for pumping the medium in the heating cycle, which has a speed regulator, or at least an on/off control, when the user needs to draw hot water from the hot water tank At or immediately after the device is stopped for heating, the operation of the water pump is reduced or interrupted, and cooler water is prevented from entering the tank from the first heat exchanger. If necessary, the burners are started, the first heat exchanger is heated, after which the pumping activity of the water pumping equipment is increased.

The combustion exhaust gas is forced to flow close to the first heat exchanger in order to exchange heat between the exhaust gas and the heat exchanger with the highest possible efficiency, for which purpose the side walls of the annular space preferably have a profile, at least partially Same outer profile as the heat exchanger to further increase the laminar gas flow along the heat exchanger.

In addition to heating the house, heat energy is needed for many other reasons in the house, such as for cleaning, for example, to send hot air to a tumble dryer, or a dishwasher or similar machine, but also for cooking, heating Ventilation for circulation in dwellings. This thermal energy is generated electrically in most dwellings, which is not advanced from an energy efficiency standpoint.

Therefore, the present invention further provides the above-mentioned device with a heat exchange unit arranged at the top of the device in contact with heat conduction and provided with an inlet for the medium to be heated and an outlet for the medium to be heated.

Further advantages, features and details of the present invention will be described according to a preferred embodiment with reference to the accompanying drawings, wherein:

Figure 1 shows a partially cutaway perspective view of a preferred embodiment of an apparatus of the present invention;

Figure 2 shows a diagram illustrating the operation of the preferred embodiment shown in Figure 1;

Figure 3 shows a partially broken perspective view of a different embodiment of the water tank shown in Figure 1;

Figure 4 shows a partial cross-sectional and partially broken perspective view of a different embodiment of the burner and main heat exchanger shown in Figure 1;

Figure 5 is a partially broken side view of a different embodiment of the main heat exchanger of Figures 1 and 4;

Figure 6 is a partially broken perspective view showing the fixing of a preferred embodiment of the device according to the present invention to a wall;

Figure 7 shows a schematic diagram of yet another preferred embodiment using the device of the present invention;

Figure 8 shows a front view of yet another preferred embodiment of the present invention; and

Figure 9 shows a perspective view of yet another preferred embodiment of a hot water tank for use with the device of the present invention.

A heating device 1 (FIG. 1) comprises a gas line 2, with a schematically shown gas regulator 3, and a schematically shown fan supplying air to a burner where the gas and air are mixed and combusted. Gas and air are mixed in a generally hollow cylindrical inner cylinder 6, which may have mixing means (not shown), with openings made in the combustion space, surrounding the combustion space with a In the heat exchanger 8, the combustion space is surrounded by a substantially cylindrical outer cylinder with a closed top. The gas is deflected downwards and directed to flow along the heat exchanger 8 between the outer wall of the inner cylinder 6 and the inner wall of the outer cylinder 9 . The inner wall of the outer cylinder 9 and the outer wall of the inner cylinder 6 are preferably slightly fitted in shape to the annular tube of the heat exchanger 8 so that there is good heat exchange between the hot gas and the contents of the heat exchanger.

The spiral heat exchanger 8 preferably has an inner tube 10 and an outer tube 11 . A star 12 in heat transfer contact with the outer tube 11 is arranged on the inner tube for good heat conduction. Flowing in the inner pipe 10 is water, referred to as mains water, which can be drawn from a tap in a dwelling as hot water and supplied via a pipe 12 . The mains water pipe 12 terminates in a connection 13 to which is also connected a supply line 14 which, via a three-way valve 16 and a water pump 15, is connected to the central heating system via a supply line 17 and a drain line 28. In pipeline.

In this embodiment, tap water is further provided through a pipeline 18, which is used to preheat tap water at a temperature such as 5-15° C., and is installed in the furnace gas discharge portion 20 through a pleated heat exchanger 19. After passing through the inner pipe 10 of the heat exchanger 8, the tap water is led to the water tank 23 through the coupling 21 and the pipeline 22 for temporary storage, so that hot water can be obtained immediately when the user turns on the tap. The water tank 23 is well thermally insulated by measures not shown, it has an inner cylinder 24 so that the incoming tap water is first driven upwards as indicated by arrow C, and then flows between the outer wall 25 of the tank and the inner cylinder 24 to the discharge pipe head 26 to drain the mains water (arrow D).

In the annular inner space of the water tank 23 is installed a second heat exchanger 27, through which flows the fluid of the central heating system provided by the line 28, the three-way valve 16 and the line 29.

The device according to the invention is preferably provided with a control unit not shown, which controls the three-way valve 16, the water pump 15 and the gas regulator 3. The three-way valve 16 is controlled either to heat the medium in an inner line, or in the case where heat must be supplied continuously to the central heating line, and the central heating line The water supply and drainage lines of the road are in continuous connection.

The curves in the graph of Figure 2 show that in a dwelling with a line of definite length between the outlet and the device of the invention, when the mains water is discharged, the temperature is at a level of 60° C. within ± 15 seconds, and not below this level. During this measurement it was found that it is better to start the pump for the main heating fluid with a slight delay, for example 5-15 seconds, or set the pump at Lower water supply levels. This prevents cold water still present in the heat exchanger from entering the tank before being heated.

In a further embodiment, the device according to the invention is provided with a mains water tank 50 ( FIG. 3 ), which can be manufactured more simply and at lower cost than the tank 23 of FIG. 1 . The heated tap water is guided through the water supply pipe 51 below the water tank 50 and into a groove between two consecutive coils 52 and 53 of the spiral plate 55, which is mounted on an outer sandwich 54 so as to provide The tap water is preheated before entering the interior of the heat exchanger 56 through an inlet opening 57. An outlet line 58 on the lower part of the heat exchanger 56 is connected to its interior to discharge heated tap water.

In a different embodiment (not shown), the spiral plate 55 could be replaced by a plurality of concentric discs arranged one above the other and having openings for the passage of water.

The heat exchanger 56 comprises a large number of generally upwardly directed tubes which are connected via a distributor (not shown) to a water supply pipe 59 for hot centrally heated water. At the top these upward facing pipes merge into a central return pipe 60 to which a central heating water discharge pipe 61 is connected.

In a different embodiment (Fig. 4) of the device of the present invention, a spiral heat exchanger 68 is installed in the space defined by an outer cylinder 65, a cover 66 and an inner cylinder 67, the heat exchanger comprising An outer tube 69 and an inner tube 70 . In order to improve the combustion efficiency, the air provided by the fan 71 is mixed with the gas provided by an air supply connection 72 using a plurality of horizontally placed plates 73, 74, 75, 76 respectively, and these plates have channel openings, and these openings are connected in succession. staggered arrangement on the plates in order to obtain a well-mixed and turbulent mixed fluid combusted in the burner 77. Gases leaving the burner 77 are directed to flow along the tubes of the heat exchanger 68 and exit through a furnace gas opening 78 below. Due to the good mixing of air and gas, complete combustion of the mixture is obtained, resulting in as little CO and NOx emissions as possible. In order to prevent the inner tube from being overheated, a closed baffle 80 is arranged above the open plates 73-76.

In a further preferred embodiment, arranged between an outer jacket 85 (FIG. 5) and a helical tube 88 is a generally cylindrical intermediate jacket 89 in which openings 87 are arranged in accordance with heat exchange The pitch arrangement of the device spiral tube 88. In a manner not shown, the spiral tube 88 may be provided with fins or plate-like protrusions to increase heat exchange. Since the opening 87 is located at the centerline of the helix, the furnace gas is forced to flow as close as possible along the outer circumference of the heat exchanger helix until a space 90 along which the furnace gas is expelled downwards. To further increase efficiency, baffles 91, 92 with openings are positioned further along the lower helical winding of the heat exchanger 88, thereby allowing the furnace gas to flow further along the heat exchanger.

For installation and maintenance, it is very important that the device of the present invention can be made very compact and can be easily fixed on a wall, such as a cabinet wall, while ensuring that the inside of the cabinet can be accessed. According to a preferred embodiment of the present invention, a cabinet 93 (FIG. 6) comprising a removable front part 94 and a rear part 95 is secured to and suspended from a strip 96 by the rear part, the strip The plate 96 is fixed to the wall W with bolts 97 . For this purpose, a flat plate 98 is fixed and preferably welded to the rear part 95, which plate fits behind a hooked end 99 of the strip 96 and hangs therefrom. Simultaneously, the bottom of rear part 95 is fixed on a profile 100 that is roughly U-shaped section, and the water supply and drain pipe of central heating water and running water pipe all can be fixed on this profile with pipe clip 101,102 etc. Various components, such as control circuits and other components (not shown), such as tap water heat exchangers and water tanks, are preferably installed on the rear portion 95 of the cabinet 93, and the cabinet 93 is firmly fixed on the back of the cabinet 93 using brackets 104 installed therein. Wall W. In another preferred embodiment (not shown), the rear part 95 of the cabinet can have pins in the lower part, which can fit into the grooves of the bracket 104, so that the cabinet 93 will not tip forward due to its own weight. .

In the embodiment of the invention shown in FIG. 7, a further heat exchanger is arranged on top of the device 1 of the invention, this heat exchanger being placed in heat transferable contact with the discharge part 20 such as the furnace gas . At the inlet of this further heat exchanger 40 relatively cool air L is introduced and the heated air is fed into a washer-dryer 41 in an energy-saving manner, indicated by arrows M and N respectively.

In the embodiment of Figure 8, in addition to the burner structure 120 (as shown in Figure 5) with a schematically drawn mixing device 121, a heat exchanger 122 is arranged for mains water instead of a water tank, thereby making the present invention Can be made more compact. Apparatus 125 has slidable connections 126 and 127 at the top for easier connection of air intake and furnace gas exhaust. The different connections for central hot water, gas and mains water are arranged at the bottom. These connections are preferably clamped between a part formed on the cabinet and a corresponding part which can be screwed to it, so that these various parts can be installed in a cabinet lying flat, and the corresponding part pressed against the connection and screwed into place. This facilitates assembly and installation operations.

Most likely because of the good thermal balance, large temperature differences do not occur in the compact design of the device according to the invention, whose Co and Nox emissions have been found to be extremely low. Measurements show that the efficiency of the device according to the invention reaches 100% of theoretical calculations, in any case greater than 95%, with very low Co and Nox emissions (maximum at 32KW: about 95ppm and about 13ppm, respectively).

A further embodiment, called hot water outlet (Fig. 9), consists of a roughly cylindrical container, which may be metal, but is preferably assembled with two plastic shells 131, 132 respectively. As a result, the two plastic shells can be connected together in a detachable manner by connecting means (not shown), such as hoops or bolts, so that the water tank can be opened and cleaned periodically. Mounted within the container 130 is a helical metal tube 133, preferably metal, on the outside of which is a tube or sleeve 134, such as a thin plastic tube (eg less than 1 mm wall thickness). Via connection head 135, hot water is taken from the heating system and fed into the spiral inner pipe 133, while water is returned to the system at the top via connection head 136. The heated tap water is brought into the container 130 through the connection head 137, while the water, which is in the space between the plastic pipe 134 and the spiral inner pipe 133, is directed downwards through the upper part into the connection head 138, a hot water line is connected to this pipe head 138. Gaskets are placed between the inner tube 133 and the plastic tube 134 at certain distances in a manner not shown in order to prevent the passage of the heated water from being blocked. A temperature detector is installed in the container in a way not shown near the connecting pipe head 137, this detector monitors whether the water temperature in the container is lower than a certain temperature, say 40°C, then hot central hot water has to be provided . The water used for heating is firstly preheated when it moves upwards, and is strongly heated when it flows downwards between the spiral pipe 133 and the plastic pipe 134 . Because of the use of a plastic tube surrounding the helical inner tube 133, a very cost-effective heat exchanger is obtained, while the central tube can use standard, commercially available materials. This structure is so compact that it can be used in conjunction with the aforementioned compact heating device.

The invention is not limited to the preferred embodiments described above. Many modifications are conceivable within the scope of the invention, which scope is defined in the following claims. An example of such a non-limiting improvement is that it is possible to place a second mains water tank into the device according to the invention, since there is still room in the interior of the device and the stable high temperature of the mains water can be improved. Guaranteed precisely.

Claims (17)

1. Devices for heating fluids, including: a first supply device for providing fuel; a second supply device for supplying an oxidizing agent; Burner equipment for combustion after the fuel and oxidizer are mixed; A first heat exchanger, which is heated by the furnace gas of the burner unit, is arranged in a helical manner around the burner unit. 2. 2. The arrangement according to claim 1, characterized in that the burner means comprises mixing means for mixing the fuel and the oxidant. 3. 2. Apparatus according to claim 2, characterized in that the mixing device comprises a plurality of flat plate members with passage openings. 4. Apparatus as claimed in any one of the preceding claims, characterized in that the open jacket is arranged around the helical heat exchanger. 5. Apparatus according to any one of claims 1-4, wherein the first heat exchanger has an inner tube and an outer tube extending around it, wherein the inner tube is at least partially passed between the inner and outer tubes Heated by the main heating fluid between. 6. Apparatus according to any one of the preceding claims 1-5, with a tank for temporary storage of hot water, characterized in that the tank includes a second heat exchanger operatively associated with the first heat exchanger even. 7. A device as claimed in any one of the preceding claims, characterized in that the heat exchanger in the tank is connected to a heating circuit. 8. Apparatus as claimed in any one of the preceding claims, characterized by a third heat exchanger for preheating tap water with furnace gas. 9. Apparatus as claimed in any one of the preceding claims, characterized in that it is provided with a water pump device with a speed regulator and at least one on/off control, characterized in that the speed is adjusted according to the moment at which the mains water is withdrawn. 10. The arrangement according to claim 9, characterized in that the annular space has an inner contour which at least slightly matches the outer contour of the heat exchanger tube. 11. Apparatus according to any one of the preceding claims, characterized in that there is a three-way flow divider which separates the first heat exchanger in a first position connected to the heating circuit and in a second position connected to the second heat exchanger. switch between positions. 12. Apparatus according to any one of the preceding claims, characterized in that it is provided with a control unit for temporarily interrupting or reducing the water supply function of the water pump. 13. Apparatus according to any one of the preceding claims, characterized in that there is a heat exchange unit mounted in heat-exchangable contact with the top of the apparatus and provided with an inlet for supplying a heating medium and an outlet for the heated medium. 14. A method of operation for a device as claimed in any one of claims 1-13. 15. A device as claimed in any one of claims 1-13, characterized by suspension means for suspending it. 16. Apparatus according to any one of claims 1-13, characterized in that it has a tank for temporary storage of hot water, characterized in that a main helical pipe is installed in the water tank, around which is arranged a preferably Outer tube made of plastic. 17. 16. Device according to claim 16, characterized in that the water tank is constituted by two or more shell-shaped parts connected in a detachable manner.

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