Heating element and method for operating a heating element

Abstract

The invention relates to a radiator (1) comprising a heat exchanger (2) and a fan (3), wherein the fan (3) is arranged in the radiator (1) and configured to generate an airflow (6) through the heat exchanger (2), and wherein the radiator (1) is configured such that, during cooling operation, the airflow direction (7) of the airflow (6) generated by the fan (3) is opposite to the airflow direction (7) during heating operation. Furthermore, the invention relates to a method for operating a radiator (1), wherein an airflow (6) is generated through a heat exchanger (2) by means of a fan (3), and wherein the fan (3) is controlled and / or operated such that, during cooling operation, the airflow direction (7) of the airflow (6) generated by the fan (3) is opposite to the airflow direction (7) during heating operation.

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 heat exchangers 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 integrated into these devices increase convection within the heat exchanger, thus increasing output even at low operating temperatures.

[0004] 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.

[0005] The invention is based on the objective of improving a radiator and a method for operating a radiator.

[0006] 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 10. Advantageous embodiments of the invention are set forth in the dependent claims.

[0007] In particular, a radiator is created comprising a heat exchanger and a blower, wherein the blower is arranged in the radiator and is configured to generate an airflow through the heat exchanger, wherein the radiator is configured such that the direction of flow of the airflow generated by the blower during cooling operation is opposite to the direction of flow during heating operation.

[0008] Furthermore, a method for operating a radiator is provided in particular, wherein an airflow is generated through a heat exchanger by means of a blower, wherein the blower is controlled and / or operated in such a way that a flow direction of the airflow generated by the blower during cooling operation is opposite to a flow direction during heating operation.

[0009] The proposed radiator and method allow the airflow direction through the heat exchanger to be adjusted for both heating and cooling operation. This improves heat transfer, particularly during cooling. In heating mode, the airflow direction for a wall-mounted radiator is ideally from bottom to top. Cold air collects at the bottom, and warm air collects at the top. The air at the bottom has a greater temperature difference compared to the supply temperature than the air at the top. However, in cooling mode, the cooled air expelled upwards with the same airflow direction would immediately sink again near the radiator and be drawn back in at the bottom.The temperature of the intake air would be reduced (mixing effect), consequently decreasing the temperature difference to the supply temperature and thus reducing cooling capacity during operation. However, if the airflow direction is reversed, in the example given from top to bottom, warmer air is always drawn in from above, and the cooled air is expelled downwards. The colder air expelled downwards remains near the floor and only rises again after warming up more slowly through mixing with the remaining (warmer) room air. This results in a greater temperature difference at the heat exchanger than with an upward airflow. Consequently, the cooling capacity of the radiator is improved.

[0010] 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).

[0011] The blower is specifically designed to generate an airflow. For this purpose, the blower is supplied with an electrical voltage. 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 unit. The blower is typically located below the heat exchanger, specifically at a predetermined distance below the heat exchanger. However, the blower can also be located above the heat exchanger.

[0012] 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.Furthermore, the radiator also includes, in particular, a (radiator) housing. The housing includes, in particular, a front, a back, a (particularly at least partially open) top and a (at least partially open) bottom, as well as a right side and a left side.

[0013] In one embodiment, the flow direction is provided that during heating operation is from bottom to top and during cooling operation it is from top to bottom. This is particularly suitable for cases where the radiator is mounted on a wall. Specifically, the control device can be configured to control the radiator such that the flow direction is from bottom to top during heating operation and from top to bottom during cooling operation.

[0014] In one embodiment, the blower comprises axial fans, and the radiator is configured to reverse the direction of rotation of the axial fan rotors. This allows for a simple change in the flow direction. In particular, this can improve cooling performance even in existing radiator designs, as only minor design modifications are required.

[0015] In one embodiment, the blower comprises at least one fan, and the radiator is configured to change the position and / or orientation of the at least one fan within the radiator to reverse the airflow direction. This allows for improved airflow provision for both heating and cooling operations. Fans are generally optimized to generate an airflow in a predetermined direction. For example, in axial fans, the rotor blades are curved or oriented in a specific way. While a volume flow in the opposite direction can be generated with such rotor blades by changing their direction of rotation, significantly higher rotational speeds are required for the same airflow because the curvature of the rotor blades is optimized for the opposite direction of rotation or airflow.Therefore, in this embodiment, the fans are designed to be repositioned and / or reoriented so that the curvature of the rotor blades, or the position and / or orientation and the resulting optimized flow direction, can also be used in the opposite direction. Specifically, the fans are reoriented by 180°. However, other changes in orientation are also possible. For example, if axial fans are used and are mounted at an angle, a change of 90° is also possible. In other words, if the axial fans are mounted at an angle (e.g., at a 45° angle to a rear wall) in the radiator, they can be tilted by 90° to change their orientation. The axial fans will still be at an angle (e.g.,The fans are arranged at an angle of 135° to the rear wall, but they then generate an airflow with a modified flow direction, in particular opposite to that of the heat exchanger. The at least one fan is, in particular, an axial fan. The blower, in particular, has several axial fans.

[0016] In one embodiment, the radiator has at least one support element, wherein the at least one fan is arranged at least in groups on or in the support element, and the orientation of the at least one fan is changed at least in groups via the support element. This allows the orientation of the at least one fan, or, in the case of multiple fans, of a group thereof, or of all fans simultaneously, to be changed. For example, the fans may be arranged on or in a support plate, which is then rotated within the radiator together with the fans. Alternatively or additionally, at least one support frame may be provided, which forms the support element or is encompassed by it.In particular, the at least one support element, especially the support plate and / or support frame, is rotated by 180° so that the airflow directions for heating and cooling operation are completely opposite to each other. The at least one fan is, in particular, an axial fan. The blower, in particular, has several axial fans.

[0017] In one embodiment, the heating element is provided with at least one stepper motor, which is configured to change the orientation of at least one fan, at least in groups. This allows the change in the orientation of the at least one fan to be motorized and, in particular, automated. For this purpose, the stepper motor is controlled and / or regulated by the control unit. The control unit provides control signals to actuate the stepper motor. The stepper motor can be arranged on at least one support element of the aforementioned embodiment and, through this support element, can change the orientation of the at least one fan, at least in groups. The stepper motor is specifically configured to change the orientation of the at least one fan by 180°, at least in groups.The fan, at least one of which is an axial fan, is present. In particular, the blower has several axial fans.

[0018] In one embodiment, the radiator is provided with at least one hand lever or handle, wherein the at least one hand lever or handle is configured to change the orientation of the at least one fan, at least in groups, via a mechanical connection. This allows for manual adjustment of the orientation. Otherwise, this embodiment can be designed like the embodiment with the stepper motor. In particular, at least one support element can be provided.

[0019] In one embodiment, the radiator is designed so that the fan can be arranged in at least two different orientations, with the at least two orientations corresponding to opposing flow directions. This allows for manual changes to the orientation or flow direction. For example, the fan, particularly the axial fans, can be manually inserted into the radiator according to the at least two orientations, for example, into rails or a holding device provided for this purpose. The fans can, for example, be arranged on a support element so that they can be removed together, at least in groups, and rotated or turned with respect to a direction of rotation or flow direction. Depending on the operating conditions, the flow direction can thus be changed.Since the radiator is typically operated exclusively in heating mode (especially in winter) and exclusively in cooling mode (especially in summer) for extended periods throughout the year, manually changing the orientation or airflow direction can be done at a time between these periods. For example, the radiator's front panel can be removed, allowing the fan's orientation or airflow direction to be changed by manually removing, turning, and reinserting the panel. The front panel is then reattached to the radiator.

[0020] In one embodiment, the radiator has at least one hydraulic cylinder, which is configured to change the orientation of the at least one fan, at least in groups, via a mechanical connection. This allows the orientation to be changed fluid-driven. Otherwise, this embodiment can be designed like the embodiment with the stepper motor or the handle. In particular, at least one support element can be provided. The at least one fan is, in particular, an axial fan. In particular, the blower has several axial fans.

[0021] In one embodiment, the heating element has at least one bimetallic spring, which is configured to change the orientation of the at least one fan via a mechanical connection. This allows the orientation to be changed without manual intervention. The parameters of the bimetallic spring are selected such that a change in orientation or flow direction occurs at a predetermined temperature threshold. Otherwise, this embodiment can be designed like the embodiment with the stepper motor or hand lever. In particular, at least one support element can be provided. The at least one fan is, in particular, an axial fan. The blower, in particular, has multiple axial fans.

[0022] 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.

[0023] The invention is explained in more detail below with reference to preferred embodiments and the figures. These show: Fig. 1a a schematic representation of one embodiment of the radiator (heating mode); Fig. 1b a schematic representation of one embodiment of the radiator (cooling mode); Fig. 2a a schematic representation of another embodiment of the radiator (heating mode); Fig. 2b a schematic representation of another embodiment of the radiator (cooling mode); Fig. 3 a schematic representation to illustrate another embodiment of the radiator (side view); Fig. 4 a schematic representation of another embodiment of the radiator; Fig. 5 a schematic flowchart of an embodiment of the method for operating a radiator; Fig. 6 a schematic diagram to illustrate the advantages of the radiator and the method.

[0024] The Fig. 1Figure 1 shows a schematic representation 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 includes a register comprising a pipe 4 with projecting fins 5. A heating or cooling medium is conveyed through the pipe 3. 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, changing the air temperature from T1 to T2. The radiator 1 can, in particular, be a heat pump radiator.

[0025] The radiator 1 is configured such 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 have a control device 8 for this purpose, 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.

[0026] The opposing flow directions 7 are in the Fig. 1a (especially heating operation) Fig. 1b (especially cooling operation) shown.

[0027] 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.

[0028] It can be provided that the blower comprises 3 axial fans 19 as fans 9, wherein the heating element 1 is configured to change the direction of rotation of the rotors of the axial fans 19 in order to reverse the flow direction 7. This is shown in the Figures 2a and 2b schematically illustrated. One direction of rotation of the rotors of the axial fans 19 is shown in the Fig. 2a (especially heating operation) opposite to the direction of rotation of the rotors of the axial fans 19 in the Fig. 2b (especially cooling operation). In particular, the axial fans 19 are controlled by the control unit 8 such that the direction of rotation is reversed. For example, the polarity of an operating voltage of the axial fans 19 can be changed for this purpose. As an example, the following Figures 2a and 2b The blower shown (3) has five axial fans (19), but in principle there could be more or fewer axial fans (19).

[0029] It may be provided that the blower 3 includes (at least one) fan 9, for example axial fan 19, wherein the radiator 1 is configured to change the position and / or orientation of the fans 9 within the radiator 1 in order to reverse the flow direction 7. This is shown schematically in Fig. 3 Figure 1 illustrates this by showing a side view of radiator 1 at several points in time. It can be seen that the orientation of the fans 9 is changed. In particular, the fans 9 are rotated 180° around an axis running horizontally along radiator 1 (into the plane of the paper or screen), so that the flow direction 7 is reversed (in the example, from a bottom-to-top flow direction 7 to a top-to-bottom flow direction 7).

[0030] In the example shown, several fans 9 are provided; in principle, more or fewer fans 9 can be provided.

[0031] It can be provided that the radiator 1 has at least one support element 10, wherein the fans 9, in particular the axial fans 19, are arranged at least in groups on or in the at least one support element 10, and the change in the orientation of the fans 9 is carried out collectively via the at least one support element 10, at least in groups. For example, a support plate can be provided on which the fans 9 are arranged and which is rotated to change the orientation of the fans 9. Additionally or alternatively, a support frame can also be provided.

[0032] It can be provided that the radiator 1 has at least one stepper motor 11, wherein the at least one stepper motor 11 is configured to change the orientation of the fans 9 at least in groups. Fig. 4Figure 11 shows a schematic representation to illustrate this embodiment. The stepper motor 11 is arranged next to the fans 9. The stepper motor 11 is connected to the fans 9, for example, via an axle 12 (or a shaft). In particular, the axle 12 is connected to a support element 10, for example, a support plate and / or a support frame, on or to which the fans 9 are arranged. Via the axle 12, the stepper motor 11 can specify an angular position of the support element 10 and thus of the fans 9. In this way, the orientation of the fans 9 can be changed, as shown in the Fig. 3 This is shown as an example. The stepper motor 11 is controlled and / or regulated in particular by means of the control unit 8.

[0033] The radiator 1 may be provided with at least one hand lever (not shown) or at least one handle, wherein the at least one hand lever or the at least one handle is configured to change the orientation of the fans 9, at least in groups, via a mechanical connection. The at least one hand lever or the at least one handle may, for example, be mechanically connected to the support element 10.

[0034] The radiator 1 may be designed so that the fan 3 can be arranged in at least two different orientations within the radiator 1, with the at least two different orientations corresponding to opposing flow directions 7. For example, the fan 3 may be removable from a housing of the radiator 1, turned around outside the housing, and then reinserted or plugged back into the housing in the reverse orientation. This is done manually, for example, whenever a heating period is followed by a cooling period and vice versa, due to weather and / or seasonal factors.

[0035] The radiator 1 may be provided with at least one hydraulic cylinder (not shown), wherein the at least one hydraulic cylinder is configured to change the orientation of the fans 9, at least in groups, via a mechanical connection. The radiator 1 may further have means for operating the hydraulic cylinder.

[0036] It may be provided that the radiator 1 has at least one bimetallic spring (not shown), wherein the at least one bimetallic spring is arranged to change the orientation of the fans 9 via a mechanical connection with the fans 9.

[0037] The Fig. 5 Figure 1 shows a schematic flowchart of an embodiment of the method for operating a radiator. The method is carried out, for example, using a radiator such as the one described in the following figures: Figures 1 to 4As shown, some process steps can be carried out by a central control system.

[0038] In process step 100, the operating status of the radiator is queried. This can be done either in a central control unit (heating control unit) or in the radiator itself.

[0039] In process step 101, it is checked whether the queried operating state includes heating or cooling operation. If the queried operating state includes heating operation, process step 200 is continued; if, however, the queried operating state includes cooling operation, process step 300 is continued.

[0040] In process step 200, it is checked whether the set (actual) flow direction corresponds to the (target) flow direction for heating operation. This can be done, for example, by querying the state of the fan and / or based on state information stored in a control unit. If this is the case, the process returns to process step 100. If, however, this is not the case, the flow direction is changed from the (actual) flow direction to the (target) flow direction for heating operation. For this purpose, for example, the orientation of axial fans is changed, as has already been described above for several embodiments. After changing the flow direction, the process returns to process step 100.

[0041] In process step 300, it is checked whether the set (actual) flow direction corresponds to the (target) flow direction for cooling operation. This can be done, for example, by querying the state of the fan and / or based on state information stored in the control unit. If this is the case, the process returns to process step 100. If, however, this is not the case, the flow direction is changed from the (actual) flow direction to the (target) flow direction for cooling operation. For this purpose, for example, the orientation of fans, especially axial fans, is changed, as has already been described above for several embodiments. After changing the flow direction, the process returns to process step 100.

[0042] The Fig. 6Figure 21 shows a schematic diagram illustrating the advantages of the radiator and the method. The y-axis (21) shows a cooling capacity according to DIN 16430 (in the version valid at the time of filing) with indexed units, allowing for relative comparison. The x-axis (20) shows a sound power level according to DIN 3744 (in the version valid at the time of filing) in dB(A). Two curves, A and B, are shown, both measured on the same radiator with axial fans in cooling mode. Curve A shows the case where the flow direction is from bottom to top, as in heating mode (prior art). Curve B shows the case where, according to the radiator and method described in this disclosure, the flow direction in cooling mode is opposite to that in heating mode, i.e., the flow direction is from top to bottom.Otherwise, the operating parameters, especially the volume flow rate, are the same in both cases. It is clearly evident that with the disclosed radiator and the disclosed method, a significantly higher cooling capacity is achieved with the same sound level or sound power of the axial fan. The increase in cooling capacity is between approximately 33% at 34 dB(A) and approximately 38% at 45 dB(A). Thus, cooling capacity can be significantly increased with the same sound level. Reference symbol list

[0043] 1 Radiator 2 Heat exchanger 3 Blower 4 Piping 5 Fins 6 Airflow 7 Flow direction 8 Control device 9 Fan 10 Support element 11 Stepper motor 12 Axis 19 Axial fan 20 x-axis (Sound power in dB(A)) 21 y-axis (Cooling capacity (index)) 100-101 Process steps 200-201 Process steps 300-301 Process steps A-curve (without change in flow direction) B-curve (with change in flow direction) T1 Temperature (incoming air) T2 Temperature (outgoing air)

Claims

1. Radiator (1) comprising: a heat exchanger (2) 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 the radiator (1) is configured such that a flow direction (7) of the airflow (6) generated by the fan (3) during cooling operation is opposite to a flow direction (7) during heating operation.

2. Radiator (1) according to claim 1, characterized by the fact that one flow direction (7) is from bottom to top during heating operation and one flow direction (7) is from top to bottom during cooling operation.

3. Radiator (1) according to claim 1 or 2, characterized by the fact that the blower (3) comprises axial fans (9), wherein the heating element (1) is configured to change the direction of rotation of the rotors of the axial fans (9) in order to reverse the flow direction (7).

4. Radiator (1) according to claim 1 or 2, characterized by the fact thatthe blower (3) comprises at least one fan (9), wherein the radiator (1) is configured to change the position and / or orientation of the at least one fan (9) within the radiator (1) in order to reverse the flow direction (7).

5. Radiator (1) according to claim 4, characterized by at least one support element (10), wherein the at least one fan (9) is arranged at least in groups on or at the at least one support element (10), wherein the changing of the orientation of the at least one fan (9) is carried out at least in groups jointly via the at least one support element (10).

6. Radiator (1) according to claim 4 or 5, characterized by at least one stepper motor (11), wherein the at least one stepper motor (11) is configured to change the orientation of the at least one fan (9) at least in groups.

7. Radiator (1) according to one of claims 4 to 6, characterized byat least one hand lever or at least one handle, wherein the at least one hand lever or at least one handle is configured to change the orientation of the at least one fan (9) at least in groups via a mechanical connection with the at least one fan (9).

8. Radiator (1) according to one of claims 4 to 7, characterized by at least one hydraulic cylinder, wherein the at least one hydraulic cylinder is configured to change the orientation of the at least one fan (9) at least in groups via a mechanical connection with the at least one fan (9).

9. Radiator (1) according to one of claims 4 to 8, characterized by at least one bimetallic spring, wherein the at least one bimetallic spring is configured to change the orientation of the at least one fan (9) via a mechanical connection with the at least one fan (9).

10. Method for operating a radiator (1) wherein an airflow (6) is generated through a heat exchanger (2) by means of a blower (3), wherein the blower (3) is controlled and / or operated in such a way that a flow direction (7) of the airflow (6) generated by the blower (3) is opposite to a flow direction (7) during cooling operation during heating operation.

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