Heat exchanger fan

Abstract

Heat exchanger fan comprising a working plane (30), wherein a leading edge (VK) of at least one fan blade (11, 12, 13) penetrates a working plane (30) in an angular range of 90° plus / minus 30° and the leading edge (VK) of the fan blade (11, 12, 13) is alternately accelerated in opposite directions by a pendulum drive within a working angle (31) in a range of at most plus / minus 85 degrees with respect to a connecting line (32) lying in the working plane (30) between a defined point on at least one flow tube (25, 26, 27) of a heat exchanger (1) and a pivot point (29) of a fan axis (28), whereby an intersection of the leading edge (VK) of the fan blade (15, 16,17) with the working plane (30) within the working plane (30) is movable back and forth between two deflection points in alternating directions of movement with a temporally defined movement profile, and wherein the intersection point of the leading edge (VK) of the fan blade (15, 16, 17) with the working surface (30) assumes in at least one position a defined shortest distance (ds) to a defined point (25, 26, 27) on at least one flow tube (21, 22, 23) of the heat exchanger (1), which is supplied by a first temperature control medium, and wherein the fan blade (11, 12, 13) releases a gaseous second temperature control medium in an alternating direction of rotation via the leading edge (VK) of the fan blade (11, 12, 13), whereby the second temperature control medium flows through the flow tube (25, 26,27) of the heat exchanger (1) is surrounded by a turbulent gas flow (110) in alternating directions of rotation, whereby the heat energy of the two temperature control media is exchanged as a heat flow from the temperature control medium with the higher temperature to the temperature control medium with the lower temperature.

Description

[0001] The invention relates to a heat exchanger fan for heat exchange between a second temperature control medium, a gaseous fluid, preferably air with a second thermal state (second enthalpy) and a first temperature control medium with a first thermal state (first enthalpy) flowing within a piping of a heat exchanger. State of the art

[0002] The gaseous second fluid is fed to the heat exchanger via a fan, through which it flows. In the prior art, an axial fan with a fan wheel rotating around a pivot axis and driven by a rotating motor is used.

[0003] Depending on the speed, the axial fan generates a spectrum of noises and operates particularly inefficiently in its center.

[0004] It is therefore an object of the present invention to provide a heat exchanger fan which does not have the disadvantages of the prior art. Summary of the invention

[0005] The present invention solves the problem by means of a heat exchanger fan according to the features of independent claim 1. Preferred embodiments and configurations of the present invention are found in the dependent claims.

[0006] The heat exchanger typically has a square or rectangular cross-section with respect to a main ventilation direction and therefore cannot be directly exposed to the airflow of a rotating fan wheel according to the prior art at its corners. Furthermore, the drive motor is located in the center of the rotating fan wheel, and no airflow is generated in the area of ​​the motor components. In any case, the rotating fan wheel has a decreasing circumferential speed towards its axis of rotation, which reduces the airflow from the fan wheel towards the center.

[0007] Therefore, an axial fan is not effective when used with a square or rectangular heat exchanger. Typically, attempts are made to compensate for this disadvantage by increasing the fan speed, which leads to increased noise emissions. To ensure airflow reaches the corners and center, air deflectors are used, which further reduce efficiency and increase noise emissions. The axial fan initially generates a largely laminar airflow, the intensity and noise of which increase with increasing radius away from the axis of rotation.

[0008] Turbulent flow is mentioned as advantageous in the prior art. In this process, turbulent flow with the highest possible Raynold number is generated by creating the highest possible flow velocity with the largest possible wetted surface area and the lowest possible viscosity of the temperature control fluids within the flow cross-section. This necessitates a high energy input, and consequently high noise emissions, to pump the temperature control fluids through the heat exchanger and its constrictions, creating cross-sectional turbulence.

[0009] The fan according to the invention has at least one fan blade which, positioned in front of the piping and any exchange surfaces potentially arranged between them (hereinafter referred to as the "heat exchange surface"), is moved vertically up and down or horizontally back and forth. In doing so, it generates a turbulent airflow along a main ventilation flow as it passes through the heat exchange surface. This turbulent airflow flows around and wets the heat exchange surface. The at least one fan blade generates the airflow across its entire width and can thus uniformly flow over the heat exchange surface across its entire width, wetting the heat exchange surface across its entire amplitude of oscillation.

[0010] The ventilation area of ​​the fan fan, which is active for heat exchange, is larger in relation to the heat exchanger area than that of the axial fan.

[0011] Furthermore, the turbulent airflow of the fan fan results in a longer wetting residence time on the heat exchanger surface than a predominantly laminar airflow. This allows for more effective heat exchange through the fan fan.

[0012] The fan fan can be operated at a lower operating frequency and lower throughput than the rotational speed required for the required throughput of an axial fan. This reduces the amplitude of the noise emission and results in a more favorable frequency spectrum, characterized by a predominantly low-frequency profile.

[0013] The fan fan operates more efficiently than the axial fan and consumes less drive energy in relation to heat exchange. The effective transfer efficiency of the heat exchanger fan, which, for the purposes of this invention, expresses the ratio of heat exchange power Pw to the electrical power Pel supplied to the fan, is defined as... meeting=Pw / Pel It's cheaper with a fan fan.

[0014] The comparison for the fan fan becomes even more favorable when the noise emission A in dB is also taken into account: treff(A)=Pw / (Pel*A[dB])

[0015] The measured noise emission A in dB of the fan fan is several times lower than the noise emission A in dB of an axial fan, with comparable turbulent ventilation effect.

[0016] The fan fan according to the invention, as a heat exchanger fan, is therefore more effective than the axial fan, emits less noise and fulfills the stated task.

[0017] The fan according to the invention, as a heat exchanger fan, comprises a working plane 30 wherein the leading edge VK of at least one fan blade 11, 12, 13 penetrates the working plane 30 at an angle of 90° plus / minus 30° and the leading edge of the fan blade 11, 12, 13 is alternately accelerated in opposite directions by a pendulum drive within a working angle 31 in a range of maximum ± 85 degrees relative to a connecting line 32 lying in the working plane 30 between a defined point on at least one flow tube 25, 26, 27 of a heat exchanger 1 and a pivot point 29 of a fan axis 28, whereby the intersection point of the leading edge VK of the fan blade 15, 16, 17 with the working plane 30 is moved back and forth within the working plane 30 between two deflection points in alternating directions of movement with a temporally defined motion profile, and wherein the intersection point of the leading edge VK of the fan wing 15,16, 17 with the working surface 30 assumes in at least one position a defined shortest distance ds to a defined point 25, 26, 27 on at least one flow tube 21, 22, 23 of a heat exchanger 1, which is flowed through by a first temperature control medium and wherein the fan blade 11, 12, 13, releasing via the leading edge VK of the fan blade, moves a gaseous second temperature control medium in alternating directions of rotation, whereby the second temperature control medium flows around the flow tube 25, 26, 27 of the heat exchanger in alternating directions of rotation in a turbulent gas flow 110 and thereby the thermal energy of the two temperature control media is exchanged as a heat flow from the temperature control medium with the higher temperature to the temperature control medium with the lower temperature.

[0018] In summary, the heat exchanger fan comprises at least one fan blade that moves back and forth within a working plane between two deflection points in alternating directions of movement with a temporally defined motion profile, wherein the intersection of the leading edge of the fan blade with the working surface assumes a defined shortest distance to a defined point on a flow tube of a heat exchanger in at least one position, through which a first temperature control medium flows, and wherein the fan blade, releasing via its leading edge, moves a gaseous second temperature control medium in alternating directions of rotation, whereby the second temperature control medium flows turbulently around the flow tube of the heat exchanger in alternating directions of rotation, and the thermal energy of the two temperature control media is exchanged as a heat flow from the temperature control medium with the higher temperature to the temperature control medium with the lower temperature.

[0019] In an advantageous embodiment of the invention, one or more fan blades are operated by one or more pendulum actuators according to the application examples for the drive from European patent application EP 21 707 610.8 and further advantageously with at least one control unit according to European patent application EP 24 154 546.6. However, other single synchronous or asynchronous or coupled synchronous or asynchronous pendulum drives are also possible.

[0020] A fan blade is advantageously moved back and forth with its leading edge VK either linearly in front of the exchange surface of the heat exchanger, or the leading edge VK performs a movement along a curved path, or the leading edge VK performs both a linear movement and a movement along a curved path in front of the exchange surface of the heat exchanger.

[0021] A fan wing advantageously features an alternatively streamlined fixed profile, such as a straight or curved solid or flexible surface, a straight or curved solid or flexible wedge shape, or a variable solid or hollow profile that deforms depending on load or position, for example, like a fish fin with a wedge-shaped double rib arrangement. The deformation of the profile or the movement pattern, such as the amplitude and / or curvature of the leading edge (VK) or the horizontal or vertical tilt angle of the fan wing, can also be adjustable and controllable depending on position or the current result of the heat exchange process, similar to the natural wingbeat of a bird or butterfly.This also makes it possible, following natural examples and in a technically advantageous way, to control both the main flow direction generated by the fan blade and the turbulence as needed.

[0022] Both a single fan blade and a multiple fan blade arranged side-by-side or one behind the other are possible. Multiple fan blades can advantageously be coupled synchronously or driven independently, either synchronously or asynchronously. When the fan blades are arranged one behind the other, they can be positioned in the direction of the main airflow of the second temperature control medium, either on one side of the heat exchanger or on both sides of the heat exchanger in such a way that they support the main flow of the second temperature control medium.

[0023] Advantageously, the heat exchanger itself can be oriented horizontally with the main flow direction of the second temperature control medium in order to minimize its footprint while increasing its overall height in this operating mode. Alternatively, and advantageously, the heat exchanger can also be oriented vertically with the main flow direction of the second temperature control medium. In this configuration, the fan assists the convection of the gaseous fluid in the heat exchanger from the warmer to the cooler side. While this design requires a larger footprint, the overall height above the base can be reduced while maintaining comparable heat exchange capacity.

[0024] Advantageously, the heat exchanger fan according to the invention is operated in conjunction with an air-source heat pump or a room dehumidifier. The at least one fan blade of the heat exchanger fan directs the warmer gaseous second temperature-control medium, in the form of ambient air, to the exchange surface of the heat exchanger, which is traversed by a cooler first temperature-control medium. In this process, the warmer second temperature-control medium exchanges thermal energy with the cooler temperature-control medium in the heat exchanger in the form of a heat flow. The thermal energy extracted from the second temperature-control medium can be further utilized in the heat pump, for example, to heat a building or the like. Conversely, with a heat flow from a warmer first temperature-control medium to a cooler second temperature-control medium, the arrangement can also be used to cool, for example, a building or the like.When used as a room drying device, the gaseous (usually air) warmer second temperature control medium in the heat exchanger exchanges heat energy in the form of a heat flow with a cooler first temperature control medium, and a device is provided to collect the resulting condensate on the cooler part of the heat exchanger.

[0025] Instead of using a rotating fan as a heat exchanger fan, as is established in the prior art, the invention introduces an oscillating fan in various advantageous embodiments as a heat exchanger fan in this technical field. The fan generates turbulent flow in the main flow direction of the second temperature control medium right from its inception and requires less energy input than a rotating axial or tangential fan. The heat exchanger can operate with larger distances between the tubes and / or plates and a lower gas flow rate, and the heat exchanger fan also generates less flow noise due to its significantly lower operating frequency.

[0026] The expert recognizes that the heat exchange surface of the heat exchanger can be made up of pipes with a round, elliptical, square or rectangular or any cross-section, as well as pipes which, in conjunction with heat exchanger plates, form the heat exchange surface of the heat exchanger.

[0027] Advantageously, at least one further fan with at least one fan blade 15, 16, 17 is arranged on the heat exchanger fan at the inlet area of ​​a second inflowing ventilated main flow 100, which supports the second inflowing ventilated main flow 100.

[0028] Advantageously, at least one further fan with at least one fan blade 15, 16, 17 is arranged on the heat exchanger fan at the outlet area of ​​a second outgoing ventilated main flow 101, which supports the second outgoing ventilated main flow 101. Brief description of the accompanying characters

[0029] These and other features of the present invention will become apparent from the following description of preferred embodiments of the present invention, which are non-limiting examples, with reference to the following figures. These show, Fig. 1. A schematic diagram of a state-of-the-art heat exchanger, Fig. 2 a fan fan according to the invention with a fan blade and a flow tube, Fig. 3 a fan fan according to the invention with several fan blades and a flow pipe, Fig. 4 a fan fan according to the invention with a fan blade and several flow tubes, Fig. 5 a fan fan according to the invention with several fan blades and several flow tubes, Fig. 6a to Fig. 6c Different orientations of a fan blade relative to a flow tube, Fig. 7a a heat exchanger in a vertical installation position, Fig. 7b a heat exchanger in a horizontal installation position, Fig. 8 a fan wing with a pendulum drive, Fig. 9 an experimental setup to determine the transfer efficiency of the fan, Fig. 10a a ventilated exchange area of ​​an axial fan on the rectangular heat exchanger, Fig. 10b a ventilated exchange area of ​​a fan on the rectangular heat exchanger, Fig. 11a and Fig. 11b a cross-section through the profile of a fan wing, and Fig. 12 a cross-section through the profile of a fan wing with a fish-fin-like, load-dependent variable profile cross-section. Detailed description of preferred embodiments

[0030] Preferred embodiments of the present invention are explained in more detail below with reference to the accompanying figures. Identical components are designated with the same reference numerals.

[0031] Fig. Figure 1 shows a schematic diagram of an example of a state-of-the-art heat exchanger for exchanging energy from hot water to cooling air. The heat exchanger 1 comprises a piped exchange area 10, in which flow tubes are traversed by a first inflowing fluid stream 200 (e.g., H2O) with an inlet temperature theta1 and a first outflowing fluid stream 201 with an outlet temperature theta2. These flow tubes are surrounded or wetted by a second inflowing main stream 100, e.g., ambient air with ambient temperature thetaamb, and a second outflowing main stream 101, and the heat flow dQ / dt is exchanged via the exchange parameters A and k.

[0032] Fig. Figure 2 shows an exemplary fan according to the invention, comprising a fan blade and a flow tube. The fan according to the invention, as a heat exchanger fan, includes a working plane 30, wherein the leading edge VK of a fan blade 11 penetrates the working plane 30 at an angle of 90° ± 30°. The leading edge VK of the fan blade 11 is alternately accelerated in opposite directions by a pendulum drive (not shown) within a working angle 31 of a maximum of ± 85 degrees relative to a connecting line 32 in the working plane 30 between a defined point on a flow tube 25 of a heat exchanger 1 and a pivot point 29 of a fan axis 28. This acceleration causes the intersection of the leading edge VK of the fan blade 11 with the working plane 30 to oscillate back and forth between two deflection points within the working plane 30 in an alternating direction of movement with a temporally defined motion profile.is moved and wherein the intersection of the leading edge VK of the fan blade 15 with the working surface 30 assumes in at least one position a defined shortest distance ds to a defined point 25 on the flow tube 21 of the heat exchanger 1, which is supplied with a first temperature control medium by an inflowing fluid flow 200 and an outflowing fluid flow 201 and wherein the fan blade 11, via the leading edge VK of the fan blade 11, moves a gaseous second temperature control medium via an inflowing ventilating main flow 100 and an outflowing ventilating main flow 101 in alternating directions of rotation, whereby the second temperature control medium flows around the flow tube 25 of the heat exchanger in alternating directions of rotation in a turbulent gas flow 110 and thereby the thermal energy of the two temperature control media is exchanged as a heat flow from the temperature control medium with the higher temperature to the temperature control medium with the lower temperature.

[0033] The first temperature control medium can be a liquid or gaseous fluid. The second temperature control medium preferably comprises a gaseous fluid. However, with a suitable heat exchanger design, the second temperature control medium can also comprise a liquid fluid in which turbulent flow can be generated by the moving fan blade.

[0034] Fig. 3 shows one of the Fig. 1. A corresponding fan according to the invention, comprising several fan blades and a flow tube. Advantageously, several fan blades 11, 12, and 13 are arranged around a flow tube 21 to generate a turbulent gas flow 110. The intersection points 15, 16, and 17 each assume a distance ds from the defined point 25 on the flow tube 21, either synchronously or asynchronously.

[0035] Fig. 4 one of the Fig. 1. A corresponding fan according to the invention, comprising a fan blade and several flow tubes. Advantageously, several flow tubes 21, 22, and 23 are arranged on a fan blade 11 to generate a turbulent gas flow 110. The intersection point 15 is located at a distance ds from the defined points 25, 26, and 27 on the flow tubes 21, 22, and 23.

[0036] Fig. 5 one of the Fig. 1. Fan fan according to the invention with several fan blades and several flow tubes. Advantageously, several fan blades 11, 12 and 13 are arranged around several flow tubes 21, 22 and 23 to generate a turbulent gas flow 110. The intersection points 15, 16 and 17 each assume a distance ds from the defined points 25, 26 and 27 on the flow tubes 21, 22 and 23, either synchronously or asynchronously.

[0037] Fig. 6a to Fig. Figure 6c shows different orientations of a fan blade with respect to a flow tube and the vertical axis.

[0038] In Fig. 6a the leading edge of the fan wing is arranged parallel to the flow path 200, 201 in the flow tube.

[0039] In Fig. 6b the leading edge of the fan wing is arranged obliquely to the flow path 200, 201 in the flow tube.

[0040] In Fig. 6c is the leading edge of the fan wing arranged vertically to the flow path 200, 201 in the flow tube.

[0041] Fig. Figure 7a shows a heat exchanger in a vertical installation position. The second, ventilating main flow 100 and 101 is supplied and discharged horizontally. This design advantageously requires a smaller footprint for the heat exchanger.

[0042] Fig. Figure 7b shows a heat exchanger in a horizontal installation position. The second, ventilating main flow 100 and 101 is supplied and discharged vertically. This advantageously promotes natural convection from the warmer to the colder temperature control medium.

[0043] Fig. Figure 8 shows a fan-shaped blade with a pendulum drive. The pendulum drive according to the application examples for the drive from application EP 21 707 610.8 operates advantageously, particularly efficiently and quietly, and is therefore particularly suitable for solving the given problem.

[0044] Fig. Figure 9 shows an experimental setup for determining the transfer efficiency of the fan. A defined flow rate of a first temperature control medium, H₂O, with a constant inlet temperature θ₁ of approximately 40°C, is supplied to the heat exchanger from a hot water boiler. The temperature difference Δθ₀ to the outlet temperature θ₂ is determined after a constant temperature difference Δθ₀ has been established. The fan is then switched on, and the resulting temperature difference Δθ₁V = θ₂V - θ₁V of the first temperature control medium is determined. After a constant temperature difference Δθ₁V has again been established, the difference to the temperature difference Δθ₀es = Δθ₁V - Δθ₀ is determined, and the time Δt required to fill a container with 10¹ (10 kg) of H₂O from this point onward is then calculated.From the temperature difference Δthetares, the mass mH₂O, and the specific heat capacity CH₂O of the first temperature control medium, the heat dissipation energy and, related to the time Δt, the heat dissipation power Pw are determined. Based on the electrical power Pel supplied to the fan, the transfer efficiency treff = Pw / Pel of the fan is calculated. An axial fan is compared, for example, with a fan-type fan.

[0045] Furthermore, the noise emission A [dB] emitted by each fan can be advantageously determined and compared.

[0046] Fig. Figure 10a shows a ventilated exchange area of ​​an axial fan on the rectangular heat exchanger. The zones of ventilation are visible in the corners of the piped exchange area 10 and in the center of the ventilated exchange area 20, where the ventilation by the axial fan decreases.

[0047] Fig. Figure 10b shows a ventilated exchange area of ​​a fan on the rectangular heat exchanger. It can be seen that the ventilation in the corners of the piped exchange area 10 and in the center of the ventilated exchange area 20 is advantageously uniformly supplied with air or wetted by the fan.

[0048] Fig. 11a and Fig. Figure 11b shows a cross-section through the profile of a fan blade. The fan blade advantageously has a curved surface. Furthermore, the curvature can advantageously be adjustable depending on the direction of movement of the fan blade.

[0049] Fig.Figure 12 shows an example of a cross-section through the profile of a fan-shaped wing with a fish-like, load-dependent variable profile cross-section. The flexible surface OF and the flexible undersurface UF of the fan-shaped wing 11, 12, 13 are hollow in the space between them and are connected to each other in a wedge shape at the leading edge VK of the fan-shaped wing. When the fan-shaped wing 11, 12, 13 rotates or is loaded, the flexible surface OF and the flexible undersurface UF of the fan-shaped wing 11, 12, 13 move in opposite longitudinal directions, causing the leading edge VK of the fan-shaped wing to align itself in the direction of the rotation instead of moving against it. This effect is known from the tail fin of fish and can be advantageously used here to create turbulence in the second temperature control medium.Advantageously, the flexible surface OF and the flexible undersurface UF of the fan wing 11, 12, 13 can be connected by one or more additional flexible crossbars QS to support this effect. Reference symbol list 1 heat exchanger 10 piped exchange area 11, 12, 13 fan wings 15, 16, 17 Intersection of the leading edge (VK) of the fan wing 20 ventilated exchange area 21, 22, 23 Flow tube 25, 26, 27 defined point on the flow tube 28 Wing axis 30 work level 31 working angles 32 connecting line 100 second inflowing ventilated main flow 101 Second outflowing ventilated main stream 110 turbulent gas flow 200 first inflowing fluid flow 201 first outflowing fluid flow ds shortest distance OF flexible surface OF UF flexible subsurface UF VK front edge QS crossbar QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 21 707 610.8 [0019, 0043] EP 24 154 546.6

[0019]

Claims

[1] Heat exchanger fan comprising a working plane (30), wherein a leading edge (VK) of at least one fan blade (11, 12, 13) penetrates a working plane (30) in an angular range of 90° plus / minus 30° and the leading edge (VK) of the fan blade (11, 12, 13) is alternately accelerated in opposite directions by a pendulum drive within a working angle (31) in a range of at most plus / minus 85 degrees with respect to a connecting line (32) lying in the working plane (30) between a defined point on at least one flow tube (25, 26, 27) of a heat exchanger (1) and a pivot point (29) of a fan axis (28), whereby an intersection of the leading edge (VK) of the fan blade (15, 16,17) with the working plane (30) within the working plane (30) is movable back and forth between two deflection points in alternating directions of movement with a temporally defined movement profile, and wherein the intersection point of the leading edge (VK) of the fan blade (15, 16, 17) with the working surface (30) assumes in at least one position a defined shortest distance (ds) to a defined point (25, 26, 27) on at least one flow tube (21, 22, 23) of the heat exchanger (1), which is supplied by a first temperature control medium, and wherein the fan blade (11, 12, 13) releases a gaseous second temperature control medium in an alternating direction of rotation via the leading edge (VK) of the fan blade (11, 12, 13), whereby the second temperature control medium flows through the flow tube (25, 26,27) of the heat exchanger (1) is surrounded by a turbulent gas flow (110) in alternating directions of rotation, whereby the heat energy of the two temperature control media is exchanged as a heat flow from the temperature control medium with the higher temperature to the temperature control medium with the lower temperature. [2] Heat exchanger fan according to claim 1, characterized by , that several fan wings (11, 12, 13) are arranged next to each other. [3] Heat exchanger fan according to claim 2, characterized by , that the fan blades (11, 12, 13) are driven synchronously with each other. [4] Heat exchanger fan according to claim 2, characterized by , that the fan blades (11, 12, 13) are driven asynchronously to each other. [5] Heat exchanger fan according to claim 1, characterized by, that at least one further fan fan with at least one fan blade (15, 16, 17) is arranged at the inlet area of ​​a second inflowing ventilated main flow (100), which supports the second inflowing ventilated main flow (100). [6] Heat exchanger fan according to claim 1, characterized by , that at least one further fan fan with at least one fan blade (15, 16, 17) is arranged at the outlet area of ​​a second outflowing ventilated main flow (101), which supports the second outflowing ventilated main flow (101). [7] Heat exchanger fan according to any one of the preceding claims 1 to 6, characterized by that several flow tubes (25, 26, 27) are arranged. [8] Heat exchanger fan according to one of the preceding claims, characterized by , that the heat exchanger (1) can be mounted vertically. [9] Heat exchanger fan according to one of the preceding claims, characterized in that the heat exchanger (1) can be mounted in a horizontal position.

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