Ventilator with outlet guide assembly and use thereof, ventilation device with same and control system, and method for increasing efficiency and / or performance of a ventilation device

Abstract

A fan (2) with a guide vane (1) for extending the fan (2) and with a fan housing is proposed, wherein the guide vane (1) has several adjustable or variable guide elements (4) for influencing the airflow leaving the fan (2), in particular for pressure recovery and / or swirl reduction. Furthermore, a ventilation device (6) comprising a turbomachine with such a fan (2) with a guide vane (1) and a control system with such a ventilation device (6) and with a data processing system is proposed.Furthermore, a method for increasing the efficiency and / or performance of a ventilation device is proposed, wherein a guide vane (1) is assigned downstream of a fan (2) in the direction of airflow, in particular radially outwards as a radial extension, which influences the airflow, in particular reducing swirl and / or providing pressure recovery. The fan (2) with guide vane (1) can be used as a diffuser or, together with sensors, in particular those mounted in the fan housing, for feeding a database and for use in a self-learning system.

Description

[0001] The present invention relates to a fan with a guide device, a ventilation device with a fan with a guide device, a control system with a ventilation device, a method for increasing the efficiency and / or performance of a ventilation device and the use of a guide device arranged radially around a fan as a diffuser. State of the art

[0002] From DE 384 0 268 C1 an air blow-out device is known which arranges a diffuser in the outlet plane of a blow-out vortex chamber.

[0003] A fan with a diffuser is known from EP 2 815 130 B1, the object here being to design a generic diffuser, a generic fan and a device in such a way that the space on the devices can be optimally used without the need for a complex design. In the diffuser according to EP 2 815 130 B1, the transitions between the sides of the wall have a twist in the vertical direction that follows the swirl of the air flow through the diffuser. The transitions therefore do not run in a straight line in the vertical direction of the diffuser wall, but are curved accordingly. The transition areas are designed to follow the direction of air flow in the diffuser or the swirl of the flow behind the fan impeller. This results in only minimal losses in the area of ​​these transitions.

[0004] Even advantageously used free-running radial fans still offer potential for efficiency improvements. Energy losses occur as a result of the actual efficiencies of all installed components. The system efficiency of the fan unit η S is formed from the product of the individual efficiencies of the installed components. These are the efficiency of the control device η R (e.g. frequency converter), the efficiency of the motor used η M and the efficiency of the fan η V (Eq. 1.1).

[0005] Furthermore, the system efficiency is defined as the ratio between the air performance PL and the electrical power absorbed from the power grid P el . (Eq. 1.2). The air performance is in turn calculated from the product of the air volume flow V delivered by the fan impeller and the static pressure increase between the suction and pressure sides of the fan impeller Δ p stat(Eq. 1.3) . η S = η R ⋅ η M ⋅ η V η S = P L P el P L = V ˙ ⋅ Δ p stat Summary and advantages of the invention

[0006] The invention relates to a fan with a guide device according to claim 1, a ventilation device with a fan with a guide device according to claim 5, a control system with a ventilation device according to claim 10, a method for increasing the efficiency and / or performance of a ventilation device according to claim 11 and a use according to claim 14 or 15.

[0007] Advantageous embodiments are specified in subclaims and described below and shown in the figures.

[0008] To increase efficiency, it is proposed to extend a fan by a guide device, in particular to extend a free-running radial fan by a guide device, which increases the efficiency of the fan unit, among other things, through a diffuser effect.

[0009] In addition, a method for increasing the efficiency or for operating a ventilation device is proposed, wherein a guide device following a fan in the air flow direction, in particular radially outward as a radial extension, influences the air flow, in particular bringing about a swirl reduction.

[0010] The efficiency increase can be achieved in two ways or through two effects. First, the fan impeller can be extended with a diffuser-type deflector, for example, in the form of a plate diffuser. Second, the deflector reduces the swirl of the air flowing out of the fan impeller.

[0011] The plate diffuser is preferably implemented as two circular rings, one mounted in front of and one behind the fan impeller. The plate diffuser can create the effect of an enlarged outlet area of ​​the fan impeller. This results in part of the dynamic pressure generated by the fan being converted into static pressure, thereby increasing efficiency.

[0012] In general, a distinction is made between dynamic pressure pd , the static pressure p stat and the altitude energy ph .The dynamic pressure is still dependent on the air density ρ and the average flow velocity c of the air stream (Eq. 1.4). The static pressure is the pressure that can be measured perpendicular to a flow. The altitude energy is composed of the air density ρ , the geodetic height h and the acceleration due to gravity g (Eq. 1.5). The three quantities can be linked using the Bernoulli equation (Eq. 1.6). Since the geodetic height at the impeller can be set to zero meters, the height energy can be neglected, simplifying the equation (Eq. 1.7). p d = ρ 2 ⋅ c 2 p h = ρ ⋅ h ⋅ g ρ 2 ⋅ c 2 + p stat + ρ ⋅ h ⋅ g = konstant ρ 2 ⋅ c 2 + p stat = konstant

[0013] If the solution developed here succeeds in reducing the proportion of dynamic pressure behind the fan impeller, more usable static pressure can be generated according to Equation 1.7. The static pressure increase of the fan can be increased. From Equation 1.4 it can be seen that the level of dynamic pressure depends essentially on the flow velocity. It is specifically proposed to decelerate the air flow behind the fan impeller. This increases the proportion of static pressure (Equation 1.7). According to the continuity equation (Equation 1.8), it is theoretically sufficient to increase the cross-section A , through which the air flows in order to reduce the flow velocity. In practice, however, the design of the cross-sectional expansion is not easily feasible, as vortex and swirl effects generate losses.

[0014] By means of the objects proposed in the independent claims, a not too abrupt enlargement is achieved.

[0015] In a preferred embodiment proposed here, a reduction in the swirl of the air flowing out of the fan impeller is achieved by supplementing a diffuser with guide vanes, in particular in the form of a bladed plate diffuser, or by designing the guide device with guide vanes. Drawings

[0016] The invention is described in more detail below with reference to the figures. Fig. 1a a guide device according to a first embodiment, Fig. 1b a guide device according to a second embodiment, Fig. 1c a ventilation device with a guide vane mounted radially around a fan impeller, Fig. 2 a guide element of the guide device made of Figure 1ain a separate perspective view, Fig. 3 the guide device Figure 1a in a schematic axial side view looking at the short side of the guide elements according to Fig. 2 , Fig. 4 a representation to illustrate an embodiment of an advantageous method with three positions of the adjustable in the guide device according to Figure 1a arranged guide elements according to Figure 2 , Fig. 5 a further illustration to illustrate an embodiment of an advantageous method with three positions of the adjustable in the guide device according to Figure 1a arranged guide elements according to Figure 2 , Fig. 6 an alternative embodiment of a guide element, wherein this has a variable length and is shown in two different lengths, Fig. 7 a representation of entry and exit angles with respect to a pivot point of a Figure 1aarranged guide element, for example according to Figure 2 and the guide element in three different angular positions, Fig. 8 a representation of the inlet and outlet angles of a guide element which can be adjusted in length, wherein the guide element is shown in two different lengths and, in addition to the inlet angle, the resulting changing outlet angle is indicated, Fig. 9 a representation of entry and exit angles with respect to a pivot point of a guide element in three different angular positions and two different lengths, whereby the guide element is rotatable about a pivot point and at the same time variable in length (i.e. a form of a combination of Fig. 7 and 8 ), Fig. 10 a top view of Fig. 1b from the front, but without the front circular ring for a better view of the rotatable guide elements, which can be adjusted in their radial distance from the fan axis, Fig. 11a representation of entry and exit angles with respect to a pivot point of a Figure 1a arranged guide element, for example according to Figure 2 and the guide element in three different angular positions, whereby the pivot point, in contrast to Fig. 7 is not located centrally or approximately centrally in the guide element, but at the radially inner end of the guide element, and Fig. 12 a representation of entry and exit angles with respect to a pivot point of a guide element in three different angular positions and two different lengths, whereby the guide element is rotatable about a pivot point and at the same time variable in length (i.e. a form of a combination of Fig. 7 and 8 ), where the pivot point, in contrast to Fig. 9 is not located centrally or approximately centrally in the guide element, but at the radially inner end of the guide element. Description of preferred embodiments of the invention

[0017] The Figures 1 to 4show details and also a possible installation situation of a guide device 1 for extending a fan 2 with a fan housing, in the illustrated embodiment of a radial fan.

[0018] The guide device 1 has several guide elements 4 for influencing the air flow leaving the fan 2.

[0019] An aerodynamic profile is preferably used as the guide element 4. The basic structure of the ventilation device 6 with the guide device 1 can Figures 1 and 2The plate diffuser shown here as an advantageous guide device or as part of an advantageous guide device 1 is preferably implemented by two circular rings 40, one of which is mounted in front of and one behind the fan impeller 20. The plate diffuser can achieve the above-described effect of an enlarged outlet area of ​​the fan impeller. However, the invention is not limited to the use of a diffuser or a plate diffuser.

[0020] The efficiency changes of the downstream guide vane 1 on the flow process of the fan unit were measured in terms of the air flow and the electrical power consumption of the fan unit. The system efficiency calculated from these values ​​serves as the primary parameter for evaluating the proposed variants of the downstream guide vane 1.

[0021] The number of guide vanes (4) depends on the operating point of fan (2) in the characteristic map. The lower the flow rate, the higher the number of blades (4) must be. In the desired flow rate range, a number of 8 to 16 blades has proven optimal.

[0022] In addition to the effect of the blade geometry, the design of the rotated 3D diffuser was investigated to determine the effect on the system efficiency of the fan unit when the air flowing from the fan impeller 20 is deflected into the flow direction of the system by means of the guide elements 4 of the guide device 1.

[0023] The guide element 4 was preferably rotated by 15° around a pivot point (see also Fig. 7 ) has been twisted. As a result, the tip of the guide vane 4 facing the fan impeller 20, i.e. the radially inner tip of the guide vane 4 (see Fig. 3) further away from the fan impeller 20. Furthermore, the side of the guide vane or guide element 4 facing the bulkhead, ie the radially outer half of the guide element 4 with respect to the pivot point of the guide element 4, was extended by 38 mm (see also Fig. 8 ). In the present example, this corresponds to the maximum possible value by which the guide vane 4 can be changed in its length 42. The side facing the motor or the fan impeller, ie the radially inner half of the guide element 4 with respect to the pivot point of the guide element 4, was shortened by 20 mm ( Fig. 3These geometric changes resulted in the cover plate of the deflector 1 facing the bulkhead (radially outer) having an outer diameter approximately 42.5 mm larger than the side facing the motor (radially inner). This provides more space for the air flowing from the fan impeller 20 to flow out of the deflector 1.

[0024] All dimensions are relative to the impeller diameter and refer to an impeller outer diameter of 455 mm.

[0025] The back of the blade is preferably rotated by 15°, cf. Fig. 3 .

[0026] Numerous experiments have shown that at a constant speed, the airflow exits the fan impeller more radially as the volume flow increases. As the volume flow decreases, however, the airflow exits more tangentially. The exact exit angle also depends on the speed of the fan impeller and its blade geometry.

[0027] If the air flows "against" the guide elements 4, this leads to an increase in flow resistance and thus in flow losses. The airflow is slowed down and loses part of the energy transferred to it by the fan 2 without being converted into static pressure, which is reflected in a decrease in efficiency. If, on the other hand, the air flows along the guide vane, it can act as a guide vane 1 and increase efficiency, see Fig. Fig. 4 .

[0028] The guide elements 4 are preferably variable in their overall shape, such as length and curvature, for example, they can be cambered to a greater or lesser extent. Alternatively or additionally, they can be specifically varied with respect to their angle of curvature 44 and / or their flank angle 45 and / or their tip angle 48 and / or their butt angle 49. The length 42 of the guide elements 4 and the aforementioned angles 44, 45, 48, 49 are Fig. 2 and Fig. 3 and defined there graphically. In addition, the guide elements 4, as explained, can be adjusted with regard to their angle of attack 46 by rotating them around the respective pivot points. Fig. 2 and Fig. 3 Finally, it also shows that the thickness 47 of the guide elements 4 preferably decreases continuously from their radially inner end to their radially outer end.

[0029] Depending on the operating point, it is further proposed to store a three-dimensional computer-implemented calculation model which, among other things, specifies the optimal angle of attack 46 of the guide elements 4.

[0030] For this purpose, the following parameters are preferably measured continuously during operation of fan 2: 1. Volume flow 2. Speed

[0031] Based on these values, the optimal angle of attack 46 of the guide elements 4 is set via at least one actuator.

[0032] As an extension of the optimization, it is proposed that a learning system independently determines the optimal operating point.

[0033] For example, the following parameters are continuously measured during operation of fan 2: 1. Volume flow in m 3 / s 2. Static pressure increase in Pa 3. Electrical power consumption in watts 4. Speed ​​in 1 / min

[0034] Based on these values, the following parameters are preferably determined: Air performance (product of volume flow and pressure increase) in watts System efficiency (quotient of air performance divided by electrical power consumption)

[0035] Using a stored characteristic map (based on the volume flow and the rotational speed), the angle of attack of the diffuser or guide element 4 is preset by means of an actuator. The actuator, implemented by a computer, varies the angle of attack 46 within a range from a minimum to a maximum possible angle of attack in order to seek optimum efficiency.

[0036] To do this, the angle of attack 46 is first changed in one direction (e.g., decreased), and the change in system efficiency is evaluated through continuous measurement. If the efficiency increases, the change is continued until a deterioration in efficiency occurs. The angle of attack 46 with the highest efficiency is then approached and permanently set. The measurements and the corresponding angle of attack are stored in a database.

[0037] If the system efficiency decreases immediately, the value representing the highest efficiency is searched for in the other direction (e.g. increasing the angle of attack).

[0038] To improve convergence, a numerical optimization method, such as the line search method, is used. By varying the step size and search direction, the dynamics of the system can be increased through faster adaptation cycles.

[0039] The optima found are stored in a database, on the basis of which a calculation model is built and constantly adapted so that the respective optimum can be quickly reached when operating conditions change.

[0040] An internal logic allows a variable cycle to be set in which periods an automatic check of the optima may be useful.

[0041] The Fig. 5 shows a single guide element 4 in the guide device 1 according to one of the Figures 1 to 4 in section, which is rotatable around its axis 5 or its pivot point there, so that the angle of attack 46 changes. In Figure 5 Three corresponding positions are shown with their respective entry angles 51, 51', 51'' and their respective exit angles 50, 50', 50''. The rotation axis 5 is arranged centrally in the guide element 5.

[0042] The Fig. 6shows an alternative embodiment of a guide element 4, which has a variable length and is shown in two different lengths. By changing the length 42 to the length 42', the angle of curvature 44 also changes to the angle of curvature 44'. The guide element 4 according to Fig. 6 is preferably formed in two parts, one part having a receptacle into which the second part can be inserted. Depending on how far the two parts are pushed together, the length of the guide element 4 changes overall. The guide element 4 according to Fig. 6 can, for example, in one of the embodiments according to Fig. 1 to 4 be used.

[0043] The Fig. 7explains once again the entry angle and the exit angle of a guide element with respect to a pivot point or an axis 5. The entry angle is initially 28° in the example shown and is then changed to 18° or 38°. Accordingly, the exit angle also changes from initially 68° to 58° or 78°. The pivot point is in Fig. 7 arranged centrally or approximately centrally of the guide element.

[0044] The Fig. 8 Explains the change in the entry and exit angle of a guide element 4, which is variable in length. In the example explained, the initial length of the guide element is 13.7 cm with an entry angle of 29° and an exit angle of 90°. By extending the guide element by 23 mm to 16.0 cm, the exit angle changes to 96°, while the entry angle remains unchanged. The guide element 4 according to Fig. 8 can, for example, according to Fig. 6be constructed in two parts and in one of the embodiments according to Fig. 1 to 4 be used.

[0045] The Fig. 9 illustrates an embodiment of a guide element 4 that is rotatable and variable in length. The guide element 4 is shown in three different angular positions (starting angle, starting angle plus 10°, starting angle minus 10°) and two different lengths (13.7 cm and 16.0 cm) with respect to a pivot point or axis 5. The guide element 4 according to Fig. 9 can, for example, according to Fig. 6 be constructed in two parts and according to Fig. 5 be rotatable and in one of the embodiments according to Fig. 1 to 4 The pivot point is in Fig. 9 arranged centrally or approximately centrally of the guide element.

[0046] The Figure 10 shows a top view of Fig. 1bfrom the front, but without the front circular ring 40 for a better view of the rotatable guide elements 4, which can be adjusted in their radial distance from the fan axis. Figure 10 is also, as already mentioned in Fig. 1b or Fig. 4 , it can be seen that the guide elements can not only be rotated in order to change their angle of attack, but that the guide elements can also be moved radially inwards or outwards with regard to their distance from the axis of rotation of the fan or the fan impeller 20. For this purpose, the circular ring 40 has front and rear (see Fig. 1b ) have corresponding slots. The guide elements can be fixed in different positions along these slots, which are preferably radially aligned. Fig. 10 shows the guide elements arranged radially inwards. Fig. 10The "distance" shown is the distance between the axis of rotation 5 of the respective guide element 4 and the radially outer circumferential line of the circular ring 40. Preferably, all guide elements 4 are arranged with the same angle of attack and the same distance.

[0047] The Fig. 11 a representation of entry and exit angles with respect to a pivot point of a Figure 1a arranged guide element, for example according to Figure 2 and the guide element in three different angular positions, whereby the pivot point 5, in contrast to Fig. 7 is not located centrally or approximately centrally in the guide element, but is located at the radially inner end or near the radially inner end of the guide element 4. Alternatively to Fig. 11 The pivot point 5 can of course also be located at the radially outer end or near the radially outer end of the guide element 4 or in a position in between. The entry angle in Fig. 11is initially 28° in the example shown and is then changed to 18° or 38°. The exit angle then changes accordingly, from an initial 68° to 58° or 78°.

[0048] The Fig. 12 shows a representation of entry and exit angles with respect to a pivot point of a guide element in three different angular positions and two different lengths, whereby the guide element 4 is rotatable about a pivot point 5 and at the same time variable in length (thus again a form of a combination of Fig. 7 and 8 ), where the pivot point, in contrast to Fig. 9 is not located centrally or approximately centrally in the guide element, but is located at the radially inner end or near the radially inner end of the guide element 4. Alternatively to Fig. 12The pivot point 5 can of course also be located at the radially outer end or near the radially outer end of the guide element 4 or in a position in between. The guide element 4 is in Fig. 12 in three different angular positions (initial angle, initial angle plus 10°, initial angle minus 10°) and two different lengths (13.7 cm and 16.0 cm). The guide element 4 according to Fig. 12 can, for example, according to Fig. 6 be constructed in two parts and according to Fig. 5 be rotatable and in one of the embodiments according to Fig. 1 to 4 be used.

[0049] The same reference numerals used in the figures are often reused across the different embodiments to identify similar features, which is not intended to be inconsistent. This serves to facilitate comparability. List of reference symbols

[0050] 1Delivery guide device 2Fan 4Guide element, guide vane 5Axis 6Ventilation device 20Fan impeller 40Annulus 42Length 44Angle of curvature 44'Angle of curvature 45Flank angle 46Angle of attack 47Thickness 48Pointed end angle 49Blur entry angle 50Entry angle 50'Entry angle 50''Entry angle 51 Exit angle 51` Exit angle 51" Exit angle

Claims

1. Fan (2) with a guide device (1) for extending the fan (2) and with a fan housing, wherein the guide device (1) has a plurality of adjustable or changeable guide elements (4) for influencing the air flow leaving the fan (2), in particular for pressure recovery and / or swirl reduction.

2. Fan (2) according to claim 1, wherein the guide elements (4) of the guide device (1) are pivotable at an angle of attack (46) about an axis (5) which is fastened or formed in particular in the fan housing or in a guide element holder, and / or wherein the guide elements (4) are not all uniformly the same, but are individually adjustable or changeable to different extents.

3. Fan (2) according to at least one of the preceding claims, wherein the guide elements (4) of the guide device (1) are variable in their length (42) and / or axial depth, in particular telescopically.

4. Fan (2) according to at least one of the preceding claims, wherein the guide elements (4) of the guide device (1) are cambered to change their overall shape in a more pronounced or less pronounced manner and / or are specifically changeable with respect to the reference angles of curvature angle (44) and / or flank angle (45) and / or pointed end angle (48) and / or blunt entry angle (49).

5. Ventilation device (6), in particular for installation in a flow duct, particularly preferably for installation in a flow duct of a ventilation system, comprising a turbomachine with at least one fan (2) with a guide device (1) according to at least one of the preceding claims.

6. Ventilation device according to claim 5, wherein the guide elements (4) are arranged radially outside a fan impeller of the fan (2) and / or or at least in the radially outer region of the fan (2) in the fan housing or in a guide element receptacle.

7. Ventilation device according to at least one of claims 5 or 6, wherein the number of guide elements (4) is in the range of one to three times the number of blades of the fan (2).

8. Ventilation device according to at least one of claims 5 to 7, wherein the guide device (1) is designed or used as a diffuser, in particular as a plate diffuser.

9. Ventilation device according to claim 8, wherein the plate diffuser comprises two circular rings provided in front of and behind the fan impeller of the fan (2).

10. Control system with a ventilation device (6) according to one of claims 5 to 9 and with a data processing system, wherein the data processing system is connected to the ventilation device (6) or integrated therein and wherein the data processing system is configured to carry out an adjustment and / or change of one or more guide elements (4) to the same or individual extent by means of a computer program installed thereon, in particular by means of artificial intelligence, wherein the artificial intelligence, if used, is configured to compare experiences of known operating states and current air parameters and to calculate control signals for the guide elements (4) therefrom.

11. Method for increasing the efficiency and / or performance of a ventilation device, in particular a ventilation device of a ventilation system, wherein a fan (2) is assigned a guide device (1) downstream in the air flow direction, in particular radially outwardly as a radial extension, which influences the air flow, in particular brings about a swirl reduction and / or pressure recovery.

12. The method according to claim 11, wherein the fan (2) with the associated guide device (1) is a fan (2) with a guide device (2) according to one of claims 1 to 4 and / or wherein the ventilation device is a ventilation device according to one of claims 5 to 9.

13. The method according to claim 11 or 12, wherein the method is computer-implemented and wherein (i) the air flow in the guide vane (1) is influenced by means of a computer program, wherein a three-dimensional calculation model is used which calculates the optimal angle of attack, and / or the optimal curvature and / or the optimal extension of guide elements (4); and / or wherein (ii) a learning system independently and self-adaptively determines an optimal operating point.

14. Use of a guide device (1) arranged radially around a fan (2) as a diffuser, in particular wherein the guide device (1) is adjustable depending on the parameters in order to act as an aerodynamic diffuser.

15. Use of a fan (2) with a guide device according to at least one of claims 1 to 4 or a ventilation device according to at least one of claims 5 to 9 together with sensors, in particular mounted in the fan housing, for feeding a database and for use in a self-learning system.

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