Heating element and method for operating a heating element

Abstract

The invention relates to a radiator (1) comprising a heat exchanger (2) with an end face (2-1) and a rear end face (2-2), which are defined by a height (H) and a width (B) of the heat exchanger (2) and are spaced apart from each other by a depth (T), and a fan (3), wherein the fan (3) is arranged in the radiator (1) and is configured to generate an airflow (6) through the heat exchanger (2), wherein an end face (2-1, 2-2) of the heat exchanger (2) exposed to the airflow (6) is arranged obliquely in the radiator (1), and wherein an air guide element (11) is arranged in an edge region (10) of the end face (2-1) and / or in an edge region (10) of the rear end face (2-2) of the heat exchanger (2), which prevents airflow through the edge region (10). a portion of the airflow (6) flowing towards the edge area (11) is directed into the heat exchanger (2).Furthermore, the invention relates to a method for operating a radiator (1).

Description

[0001] The invention relates to a radiator and a method for operating a radiator.

[0002] The long-standing trend towards heat pumps in the field of heat generators increasingly requires the use of radiators in residential and commercial buildings, which are particularly efficient at low flow temperatures and can meet the required heat demand.

[0003] In addition to underfloor heating, fan coil units or so-called heat pump radiators are typically used here. Both products allow for wall mounting similar to a conventional radiator. The fans, especially blowers, built into these devices increase convection within the heat exchanger, thus increasing output at low operating temperatures.

[0004] The blower, and especially the fans, can be operated across a speed range. The blower does not operate at a constant speed; instead, a control system regulates the blower, and especially the fans, within this speed range to achieve the desired temperature as effectively as possible. It is important to note that the sound emitted by the blower, and therefore the noise level, increases with increasing speed.

[0005] A heat pump radiator is known, for example, from EP 1 462 748 A1. There, the heat pump radiator consists of a heat exchanger provided in an open housing, which essentially comprises one or more tubes on which one or more rows of fins are provided at intervals between each other, the distance between the fins being at least three millimeters, and wherein at least one fan is provided above the heat exchanger, which draws air through the heat exchanger.

[0006] The invention is based on the objective of improving a radiator and a method for operating a radiator, particularly with regard to performance.

[0007] The problem is solved according to the invention by a radiator with the features of claim 1 and a method with the features of claim 8. Advantageous embodiments of the invention are set forth in the dependent claims.

[0008] In particular, a radiator is created comprising a heat exchanger with a front face and a rear end face, which are defined by a height and a width of the heat exchanger and are spaced apart from each other by a depth, and a fan, wherein the fan is arranged in the radiator and is configured to generate an airflow through the heat exchanger, wherein a front face of the heat exchanger exposed to the airflow is arranged obliquely in the radiator, and wherein an air guide element is arranged in a periphery of the front face and / or in a periphery of the rear end face of the heat exchanger (each), which prevents airflow through the (respective) periphery and directs a portion of the airflow approaching the periphery into the heat exchanger.

[0009] Furthermore, a method for operating a radiator is provided in particular, wherein an airflow is generated by means of a blower through a heat exchanger, having a front face and a rear front face, which are defined by a height and a width of the heat exchanger and are spaced apart from each other by a depth, wherein a front face of the heat exchanger is approached obliquely by the airflow, wherein in a boundary region of the front face and / or in a boundary region of the rear front face of the heat exchanger (each) an air guide element prevents flow through the (respective) boundary region and a portion of the airflow approaching the boundary region is directed into the heat exchanger.

[0010] The proposed radiator and method enable improved radiator performance in both heating and cooling modes. Specifically, at the same fan speed and therefore the same noise emission, heating output can be increased in heating mode and cooling output in cooling mode. The radiator and method also ensure that the heat exchanger is uniformly supplied with airflow, thus optimizing the utilization of the air volume flow for heat transfer.

[0011] The radiator is designed so that the heat exchanger is positioned within it such that one end face of the heat exchanger, exposed to the airflow, is angled within the radiator. In other words, the air emanating from the fan at any given time strikes different parts of the end face at different times. Specifically, the end faces of the heat exchanger are positioned at an acute angle to the front and back of the radiator, respectively. This angled design allows for a larger surface area through which air flows, even with a reduced radiator depth. In particular, the angled heat exchanger enables the use of a radiator with conventional dimensions, meaning a depth comparable to that of standard radiators.This allows for increased performance with a standard installation depth.

[0012] It is further provided that an air guide element is arranged in an edge region of the front face and / or in an edge region of the rear end face of the heat exchanger (each). The edge regions are located, in particular, on different end faces. With regard to the dimension of installation height, the edge regions are located, in particular, at different ends of the end faces. The edge regions are located, in particular, in corner regions of the heat exchanger defined by the end faces and the installation depth. The (respective) air guide element prevents airflow through the (respective) edge region and directs a portion of the airflow approaching the edge region into the heat exchanger. This is based on the idea that, due to the inclined end faces or the inclined heat exchanger, sections (or...) in the edge regions...Corner areas exist where part of the airflow bypasses the heat exchanger without heat exchange taking place, or where the air flows through the heat exchanger for a reduced length, resulting in less heat exchange compared to other sections away from the edges. In the bypassing portion of the airflow, the pressure loss is almost zero; there is no interaction with the heat exchanger at all, so this part remains unused. In the portion with the reduced length, the pressure loss is lower compared to the pressure loss of the remaining volume flow that flows through the heat exchanger outside the edges (i.e., especially in the center), so optimal heat transfer also does not occur. With the help of the air guide element, or...The air guide elements allow this part to be directed into the heat exchanger, so that heat exchange is greater for this part as well, thus increasing the performance of the radiator.

[0013] The air guide element located in the edge region of the end face and / or the air guide element located in the edge region of the rear end face of the heat exchanger is, in particular, arranged directly and / or immediately on the end face or the rear end face of the heat exchanger. In other words, the respective air guide element rests directly against the respective end face of the heat exchanger. Specifically, the air guide element is in mechanical contact with the end face or the heat exchanger on the respective end face. On the respective end face, the air guide element can be mechanically connected to the heat exchanger, for example, by means of a weld, adhesive bond, and / or a plug, clamp, and / or snap-fit ​​connection. At the respective locations of the air guide plates, that is, in the respective edge regions on the end faces, this creates, in particular, an air inlet and an air outlet into the heat exchanger.prevented from the heat exchanger.

[0014] In particular, it is provided that an air guide element is arranged in an edge region of the front face and in an edge region of the rear front face of the heat exchanger.

[0015] The heat exchanger comprises, in particular, a coil or at least one convection plate. The coil includes, for example, one or more pipes through which a heating or cooling medium is circulated. Flat fins are arranged, for example, on these pipes, along which air is guided and heat exchange occurs either towards the air (heating operation) or towards the fins (cooling operation). The at least one convection plate is, for example, arranged on a heating plate. Air is guided along the at least one convection plate, and heat exchange occurs either towards the air (heating operation) or towards the at least one convection plate (cooling operation).

[0016] The blower is specifically designed to generate an airflow. For this purpose, the blower is provided with an electrical supply voltage.

[0017] The blower can, for example, comprise one or more fans. A fan can be, for example, an axial fan, a cross-flow fan, or a radial fan (centrifugal fan). The blower, and in particular its speed, is controlled and / or regulated by a control device. The blower is located, in particular, below the heat exchanger, specifically at a predetermined distance below the heat exchanger. However, the blower can also be located above the heat exchanger.

[0018] The radiator is, in particular, a fan-assisted convector. The radiator is, in particular, a fan-assisted heat exchanger. The radiator enables, in particular, both heating and cooling operation. The radiator is, in particular, mounted near the floor on a wall. The radiator is, in particular, a heat pump radiator. The radiator may also include a control unit and / or an operating unit. The control unit is, in particular, designed to control the radiator, depending on the operating state (heating or cooling), such that the direction of the airflow corresponds to the respective operating state. For this purpose, the control unit, for example, queries and / or receives information about the operating state and generates corresponding control signals. Furthermore, the radiator may include an interface for remote control and / or for connection to a building management system.

[0019] Furthermore, the radiator also includes, in particular, a (radiator) housing. The housing includes, in particular, a front (housing front wall), a back (housing rear wall), a (particularly at least partially open) top and a (at least partially open) bottom, as well as a right side and a left side (side walls).

[0020] In one embodiment, the height of the heat exchanger is greater than its depth. This improves heat transfer efficiency.

[0021] In one embodiment, the installation height is at least three times the installation depth. This allows for a further increase in performance. In particular, it can be provided that the installation height is at least five times the installation depth.

[0022] In one embodiment, the size and / or arrangement of the air guide elements is symmetrical with respect to an opposing flow direction through the heat exchanger. This ensures that the same increase in performance can be achieved when reversing the flow direction. Reversing the flow direction is particularly useful when switching from heating to cooling mode in a wall-mounted radiator.

[0023] In one embodiment, the effective length of the air guide elements at the heat exchanger corresponds to the installation depth of the heat exchanger. This maximizes the performance increase. The underlying principle is that the size of sections in the vertical direction, where the portion of the airflow (without the air guide elements) flows past the heat exchanger or at least through it for a reduced length, is determined by the installation depth. These sections have an effective length in the vertical direction that corresponds to the installation depth. By selecting the effective length of the air guide elements to be exactly the same as the installation depth, airflow through these sections can be effectively prevented, and the airflow is directed into the heat exchanger within these sections.

[0024] In one embodiment, the air guide element forms at least two sides of a triangle in cross-section, with one surface of the air guide element coinciding with one of the sides being arranged on the heat exchanger. This allows for the creation of an air guide element suitable for both flow directions. In particular, one of the two sides prevents airflow through the edge region and forces the airflow to remain within the heat exchanger, while the other side achieves this for an airflow from the opposite flow direction (i.e., in the reversed flow direction). Furthermore, the other side can prevent turbulence formation behind the air guide element (i.e., in any gap that would otherwise exist between the heat exchanger and the air guide element), thereby preventing negative noise generation.

[0025] In one embodiment, the air guide element is designed as an air baffle that at least partially abuts the heat exchanger. This allows for simple and material-saving manufacturing of the air guide element, for example, by stamping. The air baffles can be designed to abut the end faces of the heat exchanger. Alternatively, the air baffles can also be designed to abut the (upper and lower) end faces (defined by a depth x length) of the heat exchanger. In this case, the cross-section of these air baffles can also form at least two sides of a triangle, as described above. However, the air baffles can alternatively have a cross-sectional shape, for example, a teardrop shape (two-dimensional freeform).

[0026] Further features for the design of the method result from the description of the radiator designs. The advantages of the method are the same in each case as in the radiator designs.

[0027] The invention is explained in more detail below with reference to preferred embodiments and the figures. These show: Fig. 1a a schematic representation to illustrate an embodiment of the radiator (especially in heating mode); Fig. 1b a schematic representation to illustrate an embodiment of the radiator (especially in cooling mode); Fig. 2 a schematic representation of embodiments of the radiator; Fig. 3a a schematic representation to illustrate the invention; Fig. 3b a schematic representation to illustrate the invention; Fig. 4 a schematic diagram to illustrate the effect that the air guide elements have in the edge regions.

[0028] The Figures 1a and 1b Figure 1 shows a schematic representation of the basic structure of an embodiment of the radiator 1. The radiator 1 comprises a heat exchanger 2 and a fan 3. In the example shown, the heat exchanger 2 comprises a register including a pipe 4, on which fins 5 projecting from it are arranged. A heating or cooling medium is conveyed through the pipe 4. Alternatively, the heat exchanger 2 can also include convection plates arranged on a heating plate. The fan 3 is arranged in the radiator 1 and configured to generate an airflow 6 through the heat exchanger 2. The airflow 6 has a flow direction 7 and is guided past the fins 5, whereby the temperature of the air changes from T1 to T2. The radiator 1 can, in particular, be a heat pump radiator.

[0029] The radiator 1 is specifically designed so that the flow direction 7 of the airflow 6 generated by the fan 3 is opposite to the flow direction 7 during heating operation during cooling operation. The radiator 1 may, for this purpose, have a control device 8 which is configured to control and / or regulate the fan 3 such that the flow direction 8 of the airflow 6 generated by the fan 3 is opposite to the flow direction 7 during heating operation during cooling operation.

[0030] The opposing flow directions 7 are in the Fig. 1a (especially heating operation) and Fig. 1b (especially cooling operation) shown.

[0031] It may be provided that the flow direction 7 is used during heating operation ( Fig. 1a , T1 <T2) von unten nach oben und die Strömungsrichtung 7 beim Kühlbetrieb ( Fig. 1b , T1>T2) is directed from top to bottom.

[0032] It can be provided that the blower comprises 3 axial fans, with the heating element 1 being configured to change the direction of rotation of the axial fan rotors in order to reverse the flow direction 7. This is shown in the Figures 1a and 1b schematically illustrated. One direction of rotation of the axial fan rotors is shown in the Fig. 1a (especially heating operation) opposite to the direction of rotation of the rotors of the axial fans in the Fig. 1b (especially during cooling operation). In particular, the axial fans are controlled by the control unit 8 such that their direction of rotation is reversed. For example, the polarity of an operating voltage for the axial fans can be changed for this purpose. For example, the blower 3 can have several axial fans, such as five or six; however, it can also have more or fewer axial fans.

[0033] The Fig. 2Figure 1 shows a side view or cross-section through an embodiment of radiator 1. Radiator 1 is basically the same as the one shown in the following. Figures 1a and 1b The radiator 1 shown is designed as follows; the same reference numerals denote the same features and terms. In the illustrated embodiment, the heat exchanger 2 comprises a plurality of tubes 4. The heat exchanger 2 has an end face 2-1 and a rear end face 2-2, which are defined by a height H and a width B (which runs perpendicularly in the plane of the paper or screen) of the heat exchanger 2 and are spaced apart from each other by a depth T. It is provided that the end face 2-1, 2-2 of the heat exchanger 2, which is exposed to the airflow 6, is arranged obliquely in the radiator 1. This also applies in particular when the flow direction 7 is reversed.

[0034] It is further provided that an air guide element 11 is arranged in an edge region 10 of the front face 2-1 and / or in an edge region 10 of the rear end face 2-2 of the heat exchanger 2 (in each case), which prevents airflow through the edge region 10 and directs a portion of the airflow 6 approaching the edge region 10 into the heat exchanger 2. In particular, it is provided that an air guide element 11 is arranged in an edge region 10 of the front face 2-1 and in an edge region 10 of the rear end face 2-2 of the heat exchanger 2. The edge regions 10 are defined in particular with reference to the overall height H, that is, the edge regions 10 are located at the extreme ends of the dimension overall height H. In particular, the edge regions 10 are located in the sections or ends of the heat exchanger 2 where it is situated near a front and a rear of the radiator 1.In the illustrated embodiment, where the radiator 1 is mounted, in particular, on a wall, one of the edge regions 10 is located at an upper end of the front face 2-1 and the other of the edge regions 10 is located at a lower end of the rear front face 2-2. The air guide elements 11 are located, in particular, directly against the heat exchanger 2. Specifically, the air guide elements 11 are in mechanical contact with the heat exchanger 2.

[0035] The air guide elements 11 improve heat transfer in the boundary regions 10 between the heat exchanger 2 and the air of the airflow 6 (heating operation) or between the air of the airflow 6 and the heat exchanger 2 (cooling operation), thereby increasing performance. The function of the air guide elements 11 in the boundary regions 10 is shown schematically in the Figures 3a and 3b clarifies. The Fig. 3aThis shows the case in which no air guide elements 11 are present in the edge regions 10. The portion of the airflow 6 that encounters the heat exchanger 2 in the edge regions 10 either flows past it or only travels a shorter path through the heat exchanger 2 compared to the rest of the airflow 6. In other words, the pressure loss due to the heat exchanger 2 (in this example, a coil) in the edge regions 10 is very low or even almost zero; this portion of the airflow 6 is therefore not used for heat transfer at all, or at least not optimally. In contrast, the Fig. 3bUnder otherwise identical conditions, the situation with the air guide elements 11 in the edge regions 10 is described. The air guide elements 11 prevent the portion of the airflow 6 that encounters the edge region 10 from flowing through it and direct it into the heat exchanger 2. This forces this portion to travel a longer path through the heat exchanger 2, thus improving heat transfer and consequently increasing heating or cooling performance.

[0036] The Fig. 4Figure 1 shows a schematic diagram illustrating the effect of the air guide elements in the boundary regions. The y-axis represents a normalized heating output (in relative units), and the x-axis represents a normalized fan speed (in relative units) of the blower's axial fans. The lower curve (20) shows measured values ​​without air guide elements, while the upper curve (21) shows measured values ​​with air guide elements under otherwise identical conditions. It is clearly evident that, at the same fan speed, the heating output is increased by approximately 35% in the lower speed range and by approximately 26% in the upper speed range due to the air guide elements. Since the emitted sound also increases with the fan speed, a greater heating output can be achieved at the same fan speed and the same sound emission / noise level.Furthermore, the same heating output can be achieved with a lower fan speed and therefore with lower sound emission or noise development.

[0037] It is specifically intended that the height H of the heat exchanger 2 is greater than the depth T of the heat exchanger 2.

[0038] It is specifically stipulated that the building height H is at least three times greater than the building depth T. In particular, the building height H is at least five times greater than the building depth T. This allows for particularly effective heat transfer.

[0039] It can be provided that the size and / or arrangement of the air guide elements 11 is symmetrical with respect to an opposing flow direction 7 through the heat exchanger 2. This embodiment is shown schematically in the Fig. 2As shown, with respect to a change in the flow direction 7 (in the example either from bottom to top or from top to bottom), the size and / or arrangement of the air guide elements 11 is symmetrical. In other words, the airflow 6 from both flow directions 7 encounters the same size and / or arrangement of the air guide elements 11.

[0040] It can be provided that the effective length L of the air guide elements 11 at the heat exchanger 2 when guiding the air corresponds to the installation depth T of the heat exchanger 2. In the Fig. 2 In the example shown, L = T. It has been shown in particular that this results in the greatest increase in performance. Specifically, this leads to optimal flow in the boundary regions 10 and thus to optimal heat transfer in the boundary regions 10.

[0041] It can be provided that the air guide element 11 forms at least two sides of a triangle in a cross-section, with a surface of the air guide element 11 coinciding with one of the sides being arranged on the heat exchanger 2. This embodiment is described in the Fig. 2The example shown illustrates this. One side of the two sides of the triangle is arranged on the heat exchanger 2. For example, the air guide element 11 is in contact with the heat exchanger 2 on this side, in particular with the fins 5 of the heat exchanger 2. The other side of the triangle extends away from the heat exchanger 2, in particular at an acute angle, in a direction away from the respective edge region 10. This other side extends, in particular, to a front or rear housing wall of the radiator 1. This other side ensures, in particular, that the portion of the airflow 6 striking the edge region 10 (given a corresponding flow direction 7) is directed into the heat exchanger 2. The two sides are, in particular, legs of an isosceles triangle, with the angle between the legs being, in particular, an obtuse angle.If alpha is the (acute) angle between one side of the triangle arranged on the heat exchanger 2 and a front (front wall of the housing) or rear (rear wall of the housing) of the radiator 1, then the obtuse angle has a value of 180° - 2 x alpha. The third side of the triangle runs parallel to a front (front wall of the housing) or rear (rear wall of the housing) of the radiator 1. The third side of the triangle does not necessarily have to be present, but serves here only to clarify or describe the embodiment of the air guide elements 11.

[0042] The air guide element 11 may be designed as an air guide plate 12 that is at least partially in contact with the heat exchanger 2. The air guide plate 12 may, for example, form the two sides, in particular the two legs, of the triangle described above. The air guide plate 12 may be attached to the heat exchanger 2. Alternatively or additionally, the air guide plate 12 may also be attached to a housing of the radiator 1. Reference symbol list

[0043] 1 Radiator 2 Heat exchanger 2-1 Front surface 2-2 Rear front surface 3 Blower 4 Piping 5 Fin 6 Airflow 7 Flow direction 8 Control device 10 Edge area 11 Air guide element 12 Air deflector B Width H Height L Effective length T Depth T1 Temperature T2 Temperature

Claims

1. Radiator (1) comprising: a heat exchanger (2) with an end face (2-1) and a rear end face (2-2), which are defined by a height (H) and a width (B) of the heat exchanger (2) and are spaced apart from each other by a depth (T), and a fan (3), wherein the fan (3) is arranged in the radiator (1) and is configured to generate an airflow (6) through the heat exchanger (2), wherein an end face (2-1, 2-2) of the heat exchanger (2) exposed to the airflow (6) is arranged obliquely in the radiator (1), and wherein an air guide element (11) is arranged in a periphery region (10) of the end face (2-1) and / or in a periphery region (10) of the rear end face (2-2) of the heat exchanger (2), which prevents airflow through the periphery region (10) and a portion of the airflow (6) flowing towards the edge area (11) is directed into the heat exchanger (2).

2. Radiator (1) according to claim 1, characterized by the fact that the height (H) of the heat exchanger (2) is greater than the depth (T) of the heat exchanger (2).

3. Radiator (1) according to claim 2, characterized by the fact that The building height (H) is at least three times greater than the building depth (T).

4. Radiator (1) according to any of the preceding claims, characterized by the fact that a size and / or arrangement of the air guide elements (11) is symmetrical with respect to an opposing flow direction (7) through the heat exchanger (2).

5. Radiator (1) according to any of the preceding claims, characterized by the fact that a length (L) of the air guide elements (11) effective at the heat exchanger (2) when guiding the air corresponds to the installation depth (T) of the heat exchanger (2).

6. Radiator (1) according to any of the preceding claims, characterized by the fact thatthe air guide element (11) forms at least two sides of a triangle in a cross-section, wherein a surface of the air guide element (11) coinciding with one of the sides is arranged on the heat exchanger (2).

7. Radiator (1) according to any of the preceding claims, characterized by the fact that the air guide element (11) is designed as an air guide plate (12) that is at least partially adjacent to the heat exchanger (2).

8. Method for operating a radiator (1), wherein an airflow (6) is generated by means of a blower (3) through a heat exchanger (2), having a front face (2-1) and a rear front face (2-2), which are defined by a height (H) and a width (B) of the heat exchanger (2) and are spaced apart from each other by a depth (T), wherein a front face (2-1,2-2) of the heat exchanger (2) is approached obliquely by the airflow (6), wherein in a boundary region (10) of the front face (2-1) and / or in a boundary region (10) of the rear front face (2-2) of the heat exchanger (2) an air guide element (11) is used to prevent the airflow through the boundary region (10) and a portion of the airflow (6) approaching the boundary region (10) is directed into the heat exchanger (2).

Images