Door module and fan cabinet for a data center cooling system

Abstract

Door module (12) for an air conditioning unit (2), in particular for a CRAH unit or a fan cabinet (2) for cooling a data center (1), comprising: a door (14) which can be pivotally attached to a housing (18) of the air conditioning unit (2) via several hinges (16), and a fan (20) mounted on the inside of the door (14), characterized by an operating interlock with a plurality of releasable fastening elements designed to firmly connect the door (14) to the housing (18) in the operating state, wherein the door (14) can only be pivoted about the hinges (16) after the fastening elements have been released.

Description

Technical background

[0001] The invention relates to the technical field of air conditioning technology, in particular the cooling of data centers and server rooms. It relates to a door module for a fan cabinet and to a fan cabinet equipped with such door modules. Such systems are typically used in the form of so-called fan walls to efficiently dissipate large heat loads, such as those generated in colocation or hyperscale data centers.

[0002] The present invention relates to a door module and a fan cabinet for a data center cooling system, wherein a pressure wall door is designed to allow easy access to the respective fan for maintenance work. State of the art

[0003] Data centers form the backbone of modern digital infrastructure. The continuous and uninterrupted operation of the servers housed within them is crucial. Server racks generate significant amounts of heat during operation, which must be reliably dissipated to prevent overheating and component failure. Typically, the operating temperature of the server racks is maintained at around 20 degrees Celsius, while the exhaust air generated by the processors can reach temperatures of 38 degrees Celsius and higher. To compensate for this temperature difference and ensure a stable operating environment, high-performance ventilation and air conditioning systems are essential.

[0004] For cooling large data centers with high heat loads and tall server racks, so-called fan wall units (FWUs) have become established. These systems typically consist of several modular units assembled to form a large wall. Each unit contains components such as heat exchangers, filters, and EC fans. The fan wall is usually installed between a hot aisle and a cold aisle in the data center. The fans draw in hot air from the hot aisle, pass it through the heat exchangers where it is cooled, and then blow the cooled air into the cold aisle, from where it is supplied back to the server racks.

[0005] These systems are modular in design to allow for flexible adaptation to different room sizes and scalability of cooling capacity. The individual modules or fan cabinets must be accessible for maintenance and repair. In particular, the fans, as mechanically moving components, are subject to wear and tear and must be able to be regularly serviced or replaced.

[0006] In the prior art, fan cabinets are known in which the fans are permanently mounted within the housing. Access is via removable side panels or service hatches. This can be cumbersome, as the technician often has to work in confined spaces inside the cabinet. Alternatively, doors secured with simple latches or snap locks are known. While these solutions offer quick access, they are often not sufficiently stable under the high pressure differentials generated by modern high-performance fans. The pressure and suction forces generated during operation can cause the door to vibrate, warp, or leak. This leads to efficiency losses, increased noise, and poses a safety risk, as an inadequately secured door could open unintentionally.

[0007] The task is therefore to create a solution for a fan cabinet that ensures both high operational reliability and stability under high pressure loads, as well as allowing easy and safe access to the components for maintenance purposes. Overview of the invention

[0008] This problem is solved by a door module with the features of claim 1 and a fan cabinet with the features of claim 8. Advantageous embodiments are the subject of the dependent claims.

[0009] The invention proposes a door module for a fan cabinet, comprising a door that can be attached to the fan cabinet via hinges. A fan is mounted on the inside of this door. According to the invention, the door can additionally be attached to the fan cabinet via a screw connection in such a way that the door can only be opened, i.e., pivoted about the hinge axis, after the screw connection has been loosened.

[0010] This design solves the problem through intelligent functional separation.

[0011] On the one hand, maintenance is significantly simplified. Modern high-performance fans can reach a considerable weight, for example, around 50 kg. By mounting the fan on the swing-out door, it can be completely removed from the cabinet body for maintenance or replacement work, making it easily accessible. This makes handling such heavy components considerably easier and safer compared to designs where a technician has to work inside the confined space of the cabinet.

[0012] On the other hand, maximum operational reliability is ensured. The separation of functions according to the invention is central here: While the hinges serve exclusively for the pivoting movement of the door in the maintenance-related, pressureless state, the screw connection is solely responsible for the secure fixing and absorption of forces during operation. During operation, the screw connection presses the door firmly and evenly against the cabinet body. The considerable overpressures generated inside the cabinet by the fan are thus completely and reliably absorbed by the screw connection and transferred into the stable structure of the cabinet body. The hinges and any simple door closing mechanism that may be present are therefore completely relieved of these forces during operation.This not only prevents the door from accidentally opening, but also reduces material fatigue at the hinges and minimizes vibrations and leakage, significantly increasing the operational reliability and energy efficiency of the overall system.

[0013] In a particularly advantageous design, the door is formed from a single, formed sheet metal part. This enables cost-effective, reproducible manufacturing while maintaining high stability.

[0014] The invention also extends to a complete fan cabinet or fan wall, consisting of a cabinet body and a plurality of the door modules according to the invention, which are arranged modularly to form a scalable cooling unit. Brief description of the characters

[0015] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying drawings. These show: Fig. 1: A schematic representation of the airflow in a data center with a fan wall. Fig. 2: A perspective view of a fan cabinet consisting of two stacked modules, with the lower door open and showing the door module according to the invention. Fig. 3: A detailed view of the in Fig. 2 fan cabinets shown. Fig. 4: A perspective view of the door module from the rear, showing the fan. Fig. 5: A frontal view of the inside of the closed door module. Fig. 6: A rear view of the door module looking towards the fan. Fig. 7: A development of a sheet metal part used to manufacture the door of the door module. Fig. 8A and Fig. 8B: Detailed views of the sheet metal part made of Fig. 7. Fig. 9: A perspective view of an arrangement of several door modules to form a fan wall. Detailed description of the embodiments

[0016] The invention is explained in more detail below with reference to exemplary embodiments and the accompanying drawings. The described features represent advantageous developments which, individually or in combination, can further develop the invention.

[0017] Fig. Figure 1 shows the basic operating principle of a cooling system in a data center 1. Such systems, often referred to as CRAH (Computer Room Air Handling) Units 2, are essential for maintaining the optimal operating temperature. The fan wall 2 according to the invention represents a specialized and highly efficient form of such a CRAH unit 2. It is strategically positioned to draw in the hot air (upper arrow) generated by the server racks 3, which collects in the so-called hot aisle 4, and to cool it by means of heat exchangers. After cooling in the fan wall 2, the cooled air (lower arrow) is blown back into the server room, for example into a cold aisle 5, from where it is supplied to the servers 3 for cooling. This continuous cycle is crucial for the stable operation of the data center 1. As shown in Figure 1, the fan wall 2 is designed to allow the airflow to be cooled by the fan wall 2. Fig. As schematically indicated in Figure 1, the respective air flows in the hot aisle 4 and cold aisle 5 can be separated from each other, for example, by partitions, guide plates or the like, in order to enable the most efficient heat cycle possible.

[0018] Fig. 2 and Fig. Figure 3 shows an exemplary embodiment of a fan cabinet that serves as part of such a fan wall 2. The cabinet has a modular design and consists here of two cabinet modules 10 arranged one above the other, each equipped with two door modules 12 according to the invention. The lower left door module 12 is shown in the open position and illustrates the interaction of the core components: the door 14, which is opened via hinges 16 (see Figure 3). Fig. 4) is pivotally hinged to the body 18 of the cabinet module 10, and the fan 20 attached to it. As in Fig. As shown in Figure 3, the lateral edge of door 14, on the opening side of door 14 when closed, rests against a mounting flange 19 of the cabinet body. This is also true on the hinge side of door 14, which is shown in the perspective view of Figure 3. Fig. 3 is concealed, a corresponding mounting bracket 19 is provided against which the hinge side of the door 14 rests when closed.

[0019] The key advantage for maintenance becomes immediately apparent here. High-performance fans 20, such as those used in these applications, can weigh considerably, for example, around 50 kg. By mounting the fan on the door 14, the entire heavy fan 20 swings completely out of the cabinet body 18 when the door is opened. This provides maintenance personnel with free and ergonomic access to the component from all sides, significantly simplifying and making inspection, cleaning, or complete replacement safer. As explained below, the door modules 12 are each secured to the cabinet body 18 by screws when closed.

[0020] The access provided by opening door 14 is not limited to the fan 20 itself. Rather, the large opening exposes the entire interior of the respective cabinet module 10. This allows service personnel convenient access to other components located in the airflow or within the housing. These include, for example, the large-surface heat exchangers responsible for the actual cooling of the air, as well as upstream filter mats that require regular replacement. Electronic components, such as the control unit for the EC fan, sensors, and actuators for temperature and pressure monitoring, are also easily accessible. The door module 12 according to the invention thus functions as a universal service portal for the entire cabinet module 10.

[0021] To simplify the assembly and disassembly of the door 14 itself, the hinges 16 can be designed as easy-to-install components. As indicated by the recesses in the sheet metal part of the door 16 (shown in Fig. 7) and corresponding openings in the cabinet module 10, the hinges 16 can, for example, be designed as clip-on or insert hinges. These can be clipped or hooked into the designated openings without tools or with minimal effort, which significantly reduces on-site assembly time.

[0022] The decisive technical innovation and the core of the operational reliability of the inventive door module 12 lies, however, in the screw connection. After the door 14 has been closed, the locking mechanism for the operation of the fan wall 2 is engaged. For this purpose, several screws are guided through corresponding openings 22 in the door 14 and screwed into corresponding threads in the frame of the cabinet body 18, or in the mounting brackets 19 of the cabinet body 18. This screw connection presses the door 14 firmly and evenly against the cabinet body 18, with an optional, intermediate seal (not shown) ensuring an airtight seal. The screw connection is circumferential, i.e.,Screws are provided both on the hinged side and on the opening side of the door 14 to transfer the forces resulting from the pressure difference between the inside and outside of the door into the cabinet body 18 via the screw connection during operation, without subjecting the hinges 16 to compressive forces. In the illustrated embodiment, a total of four screws, two per door side, are used to fasten the closed door 14 to the cabinet body 18.

[0023] The significant static overpressures or underpressures generated by the fan 20 during operation are now completely absorbed by this positive-locking screw connection and reliably transferred into the stable cabinet body 18. The hinges 16 and the optional locking mechanism are thus completely relieved of these forces during operation. This reliably prevents the door 14 from springing open, minimizes vibrations and material fatigue at the hinges 16, and increases energy efficiency by preventing leaks.

[0024] Fig. 4 and Fig. Figure 6 shows the detailed assembly of the fan 20 on the door 14. The fan 20 is enclosed in an aerodynamically shaped inlet ring 24, which in turn is attached to a mounting plate 26. This unit is screwed to the inside of the door 14 using screw connections 28.

[0025] The production of door 14 itself takes place as described in Fig. 7, Fig. 8A and Fig. 8B shown, preferably from a single, precisely stamped and bent sheet metal part, wherein also, as in Fig. Figure 8B shows that the appropriate recesses 32 for the hinges 16, the required screw holes 28 for attaching the mounting plate 26 of the fan 20 to the door 14, and the screw holes 22 for screwing the door 14 to the cabinet body 18 are already provided. This method is not only extremely cost-efficient and saves material, but also ensures high repeatability and structural integrity of the finished door 14.

[0026] Finally, it shows Fig. 9, how several of the door modules 12 described above or cabinet modules 10 equipped with them can be combined to form a complete fan wall 2 in order to precisely adapt the cooling capacity to the requirements of the respective data center 1.

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