Device and method for controlling flow in a cooling circuit

Abstract

A device for controlling the flow rate in a cooling circuit (10') comprising a first duct (12) allowing the circulation of a cooling fluid to and from an element to be cooled (14), a second duct (16) fluidically connected to the first duct (12), the second duct (16) allowing the circulation of the cooling fluid to and from a cooling element (18), a bypass circuit (20) allowing the circulation of the cooling fluid in the first duct (12) by bypassing the second duct (16), and a first pump (22) for circulating the cooling fluid in the first duct (12), the device further comprising a second pump (26) for circulating the cooling fluid in the second duct (16), and a control device for controlling the power of the second pump (26).

Description

Technical Field

[0001] This invention relates to an apparatus and method for controlling the flow rate in a cooling circuit. Background Technology

[0002] In a cooling circuit, a cooling fluid (typically but not necessarily water-based, with or without additives) flows toward and away from the element to be cooled. Near the element, heat is transferred from the element to the cooling fluid, thus lowering the temperature of the element. As the cooling fluid continues to flow, it transfers heat from the element to be cooled to the element to be heated (hereinafter referred to as the cooling element), which in turn cools the fluid, allowing it to flow back toward the element to be cooled.

[0003] The component to be cooled can be almost anything, but typical examples are mechanical or electrical parts, such as components of a projector, which must be cooled during use to prevent damage from overheating. Similarly, the cooling component can be anything, such as a heat sink, which has little or no overheating problem.

[0004] In a particular type of cooling circuit, the circuit includes: a first conduit allowing cooling fluid to flow toward and away from the component to be cooled; a second conduit, fluidly connected to the first conduit, also allowing cooling fluid to flow toward and away from the component; a bypass conduit allowing cooling fluid to bypass the second conduit and circulate within the first conduit; and a pump for circulating the cooling fluid within the first conduit. The temperature in the cooling circuit can be controlled by controlling the amount of cooling fluid flowing through the bypass conduit and thus around the second conduit. This is necessary because some components to be cooled have preferred operating temperature ranges and therefore should neither become too hot nor too cold. On the other hand, for safety purposes, it should be ensured that the flow rate of the cooling fluid is constant during the operation of these components, such that the pump used to circulate the cooling fluid in the first conduit always operates at a certain power and / or a certain flow rate, and the temperature in the cooling circuit is controlled by actuated three-way valves that direct more or less fluid into the second conduit and the bypass conduit respectively, while maintaining a substantially constant flow rate in the first conduit. An example of such a cooling circuit is shown in Figure 1.

[0005] While such devices are widely used, the use of actuated three-way valves has proven to have certain drawbacks. Actuated three-way valves have a relatively slow response time, typically ranging from approximately 30 to 120 seconds, to reach the intended open / closed position for adjusting flow in bypass and secondary pipelines. Furthermore, actuated three-way valves require specific electronic infrastructure, such as a certain supply voltage and control logic that may not yet be available in the installation environment (e.g., at a projector where cooling is required). Additionally, reliable three-way valves and their actuators can be considerably more expensive than other parts of the cooling circuit. Moreover, some three-way valves are sensitive to their operating orientation; that is, they may not function properly if used inverted, which can be problematic if the component being cooled is a moving part that can theoretically operate in many different installation positions. Summary of the Invention

[0006] The present invention aims to solve the problems associated with the use of a three-way valve in a cooling circuit of the above type, which includes a first conduit, a second conduit, and a pump, by providing an apparatus and method for controlling the flow rate in such a cooling circuit.

[0007] These problems are solved by the apparatus according to claim 1 and the method according to claim 8, respectively. Advantageous embodiments are defined in the dependent claims.

[0008] The basic concept of this invention is to replace the three-way valve with another pump (i.e., a pump arranged in the second conduit before or after the cooling element). Since this other pump is arranged in the second conduit, it is referred to below as the second pump, while the pump arranged in the first conduit is referred to below as the first pump.

[0009] Using a second pump has unexpectedly many advantages. Such a pump for a specific cooling circuit is typically significantly cheaper than an actuated three-way valve used in the same cooling circuit. A major advantage is the response time: if the second pump is, for example, a centrifugal pump, its response time is typically less than 10 seconds, and there are usually no restrictions on its operating orientation.

[0010] Other advantages and details of the invention will become apparent from the following detailed description of preferred embodiments, taken in conjunction with the accompanying drawings, which include seven figures. Attached Figure Description

[0011] Figure 1 is a schematic diagram of a device for controlling the flow rate in a cooling circuit according to the prior art.

[0012] Figure 2 This is a schematic diagram of a device for controlling the flow rate in a cooling circuit according to an embodiment of the present invention.

[0013] Figure 3It is a chart showing the relationship between different traffic volumes.

[0014] Figure 4 A connection module according to an embodiment of the present invention is shown.

[0015] Figure 5 It shows that according to Figure 4 The first element of the connection module.

[0016] Figure 6 It shows that according to Figure 4 The second element of the connection module.

[0017] Figure 7 It shows that according to Figure 4 Cross-sectional view of the connection module. Detailed Implementation

[0018] Figure 1 is a schematic diagram of a device for controlling the flow rate in a cooling circuit (represented by 10) according to the prior art. The cooling circuit 10 includes: a first conduit 12 (represented by a dashed rectangle for illustrative purposes) allowing cooling fluid to flow toward and away from the element 14 to be cooled; a second conduit 16 (represented by another dashed rectangle for illustrative purposes), fluidly connected to the first conduit 12, allowing cooling fluid to flow toward and away from the cooling element 18; a bypass conduit 20 allowing cooling fluid to bypass the second conduit 16 and circulate within the first conduit 12; and a pump 22 disposed in the first conduit 12 for circulating the cooling fluid. In this figure and other schematic diagrams (…), Figure 2 In the diagram, arrows are used to indicate the pipes forming pipes 12, 16 and bypass pipe 20, and these arrows also indicate the direction of the cooling fluid flow.

[0019] To control the amount of fluid flowing through the bypass line 20 and thus bypassing the second line 16, an actuated three-way valve 24 is provided at the connection between the first line 12 and the second line 16. The actuated three-way valve 24 has three branches: one connected to the first line 12, one to the second line 16, and one to the bypass line 20. The actuated three-way valve 24 directs more or less fluid into the second line 16 and the bypass line 20 respectively, while maintaining a substantially constant flow rate in the first line. By controlling the amount of fluid flowing through the bypass line 20, the temperature in the cooling circuit 10, particularly the temperature in the first line 12, can be controlled. Note that, as used herein, the term "fluid connection" means that the first line 12 and the second line 16 are connected to allow fluid to flow from one line to the other in principle; of course, this flow may not occur when the branch of the three-way valve 24 leading to the second line 16 is closed.

[0020] Figure 2This is a schematic diagram of an apparatus for controlling the flow rate in a cooling circuit (generally indicated by 10') according to the present invention. Since the cooling circuit 10' has, in principle, the same reference numerals are used to denote elements corresponding to those shown in FIG. 1. Similarly, for illustrative purposes, the first conduit 12 and the second conduit 16 are indicated by dashed rectangles, and all pipes forming conduits 12, 16, and the bypass conduit 20 are indicated by arrows, which also indicate the direction of the cooling fluid flow. The first conduit 12 allows the cooling fluid to flow toward and away from the element 14 to be cooled, and the second conduit 16 (which is fluidly connected to the first conduit 12) allows the cooling fluid to flow toward and away from the cooling element 18. The bypass conduit 20 allows the cooling fluid to bypass the second conduit 16 to circulate in the first conduit, and a first pump 22 is disposed in the first conduit 12 for circulating the cooling fluid in the first conduit 12.

[0021] In some embodiments of this disclosure, in addition to the first pump 22, a second pump 26 is provided for circulating cooling fluid in the second pipe 16, and a control device (not shown) for controlling the power of the second pump is also provided, thereby making the actuated three-way valve unnecessary. By employing the second pump 26 arranged in the second pipe 16, the temperature in the first pipe 12 can be easily controlled by controlling the second pump 26. Similarly, "fluid connection" means that the first pipe 12 and the second pipe 16 are connected to allow fluid to flow from the first pipe 12 into the second pipe 16 in principle, which does not occur when the second pump 26 is turned off.

[0022] In one embodiment of the device, the first pump 22 and the second pump 26 are of the same type, particularly centrifugal pumps. This has several advantages. For example, using the same type of pump means that the electrical infrastructure for the second pump 26 already exists, since the first pump 22 originally required that electrical infrastructure. Compared to actuated three-way valves, pumps, especially centrifugal pumps, have a fast response time and are generally insensitive to orientation during their operation.

[0023] Figure 3This is a schematic diagram illustrating the main relationships between three different flow rates during the operation of the cooling circuit according to the present invention. The horizontal axis (x-axis) 28 represents the "power" of the second pump 26, which can be given in any suitable unit, such as the current supplied to the pump or the pump speed, while the vertical axis (y-axis) 30 represents the flow rate of the cooling fluid. Line 32 represents the flow rate of the cooling fluid in the first pipe, line 34 represents the flow rate of the cooling fluid in the second pipe, and line 36 represents the flow rate of the cooling fluid in the bypass pipe. In the operation of the cooling circuit according to the present invention, the first pump ensures that the flow rate of the cooling fluid in the first pipe is constant, and therefore, in principle, constant, as shown by line 32. If the second pump is turned off, in principle, no fluid flows in the second pipe, and all fluid from the first pipe flows through the bypass pipe. As the power increases, more and more fluid flows in the second pipe (as shown by line 34), and less and less fluid flows through the bypass pipe (as shown by line 36). In some embodiments, the flow diameter of the bypass conduit can be selected to be significantly smaller than the flow diameters of the first and second conduits (e.g., three to six times smaller). This can help ensure that, with sufficient power supplied by the second pump, substantially all cooling fluid from the first conduit is directed through the second conduit and thus cooled. However, in other embodiments, the flow diameter of the bypass conduit can be selected to be substantially the same as or identical to the flow diameters of the first and second conduits, which advantageously allows the use of the same pipe to form the cooling loop.

[0024] Figures 4 to 7 A connection module according to an embodiment of the present invention is shown (in) Figure 4 and Figure 7 The entire structure is represented by 40 and its main components. The connection module is designed to establish a fluid connection between the first pipe 12 and the second pipe 14.

[0025] The connecting module 40 is basically composed of two components 42 and 44, which are connected in the assembled state by screws 46. Figure 5 Two are marked in the middle) and the corresponding threaded hole 48 ( Figure 6 (Two are marked in the image) and mounted together. However, connection module 40 may include any fastening mechanism capable of securing elements 42 and 44. The module has four ports 50, 52, 54, and 56. (As shown...) Figure 7 As shown in the cross-sectional view, ports 42 and 44 are connected via internal flow channel 58, and ports 46 and 48 are connected via internal flow channel 60. Bypass pipes 62 and 64 branch off from flow channels 58 and 60 respectively, forming a single bypass pipe in the assembled state, i.e., when components 42 and 44 are attached to each other. Figure 2(20 in the text). The flow diameter of the bypass pipes formed by bypass pipes 62 and 64 is significantly smaller than the flow diameter of flow channels 58 and 60, as well as the general flow diameter of the first and second pipes. In some further embodiments, a sealing material 80 is used at the connection between the respective surfaces of elements 42 and 44 to prevent cooling fluid from flowing out between the respective surfaces of elements 42 and 44.

[0026] The connection module 40 forms an "interface" between the first pipe and the second pipe, and can be integrated, for example, into... Figure 2 In the schematically illustrated cooling circuit, port 52 is formed for the cooling from the first conduit ( Figure 2 The inlet of the cooling fluid (as shown by arrow 66) at 12) has a port 50 formed for flow to the second conduit ( Figure 2 Port 54 forms an inlet for cooling fluid from the second pipe (as shown by arrow 70), and port 56 forms an outlet for cooling fluid flowing to the first pipe (as shown by arrow 72).

[0027] In some embodiments of this device, a control device (not shown) communicates with at least one temperature sensor (not shown) that measures the temperature of the element to be cooled. Figure 2 14) temperature and / or first pipe ( Figure 2 The temperature of the cooling fluid in (12) is particularly important in the first pipe after the element being cooled. This allows for automatic control of the temperature in the first pipe, and thus the "cooling capacity" of the cooling circuit 10'. Alternatively, a temperature sensor can be placed at the connection module 40 to measure the temperature of the mixed flow. If this sensor can communicate with the control device, the temperature can be controlled via a second pump ( Figure 2 26) Automatically control the cooling capacity of the cooling circuit.

[0028] In some further embodiments of this device, a control device (not shown) communicates with exactly one temperature sensor (not shown) that measures the temperature of the element to be cooled ( Figure 2 (14) temperature or first pipe ( Figure 2 The temperature of the cooling fluid in 12) is particularly important for the temperature of the cooling fluid in the first pipe after the element to be cooled. The advantage of this approach is that the setup can remain very simple and cost-effective.

[0029] This disclosure also provides a method for controlling, such as Figure 2A method for controlling the flow rate in a cooling circuit, the cooling circuit comprising: a first conduit allowing cooling fluid to flow toward and away from a component to be cooled; a second conduit fluidly connected to the first conduit, the second conduit allowing cooling fluid to flow toward and away from the cooling component; a bypass conduit allowing cooling fluid to bypass the second conduit and circulate in the first conduit; a first pump for circulating the cooling fluid in the first conduit; and a second pump for circulating the cooling fluid in the second conduit, wherein the method comprises: controlling the power of the second pump to adjust the amount of cooling fluid flowing through the bypass conduit.

[0030] In some embodiments of the method, the first pump operates at a constant power and / or a constant flow rate, and the second pump operates at a variable power based on the desired temperature of the cooling fluid flowing to the element to be cooled.

[0031] In some further embodiments of the method, the power of the second pump is controlled based on the temperature of the cooling fluid in the first pipe, or the temperature of the element to be cooled, or both.

[0032] Generally, when the second pump is off, the resistance of the second conduit is much higher than that of the bypass conduit, so all the cooling fluid flows through the bypass conduit. As pump power increases, some cooling fluid will begin to flow through the second conduit, while less will flow through the bypass conduit. When pump power increases to the point where the flow rate in the second conduit equals the flow rate in the first conduit, the flow rate through the bypass conduit approaches zero. Therefore, the device can allow virtually 100% of the flow to pass through the bypass conduit (pump off), virtually 0% of the flow to pass through the bypass conduit (pump at maximum), and any value in between (see also...). Figure 3 ).

[0033] While centrifugal pumps are currently the preferred choice, alternative pump types, such as positive displacement pumps, peristaltic pumps, or diaphragm pumps, may be used in certain situations depending on the overall design of the cooling circuit and its specific application.

[0034] To control the pump speed, especially the second pump (in typical use cases, the first pump will operate at a constant speed / flow), control devices such as variable frequency drives (VFDs) or pulse width modulation (PWM) controls can be used to more precisely manage the flow and temperature in the cooling loop.

[0035] In addition to temperature sensors, flow sensors can also be integrated into the cooling circuit to provide real-time data on the flow rate through the first and second pipes, enhancing the ability to maintain desired operating conditions.

[0036] For certain applications, redundancy features, such as standby pumps or automatic switching systems, can be employed to ensure continuous operation of the cooling circuit in the event of a pump failure.

[0037] An integrated control system with a user interface can be used, which allows for manual adjustment, preset temperature profiles, or remote monitoring and control, thereby enhancing the functionality of the cooling circuit.

[0038] Depending on the amount of heat absorbed by the cooling elements, an energy recovery system can be used to capture waste heat from the cooling elements and reuse it for other purposes, thereby improving the overall energy efficiency of the cooling circuit.

[0039]

Claims

1. An apparatus for controlling the flow rate in a cooling circuit (10'), the cooling circuit comprising: The first conduit (12) allows cooling fluid to flow toward and away from the element to be cooled (14). The second pipe (16) is fluidly connected to the first pipe (12), and the second pipe (16) allows cooling fluid to flow toward and away from the cooling element (18). A bypass pipe (20) allows the cooling fluid to bypass the second pipe (16) and circulate in the first pipe (12), and A first pump (22) is used to circulate the cooling fluid in the first pipe (12). Its features include: The second pump (26) is used to circulate the cooling fluid in the second pipe (16), and A control device for controlling the power of the second pump (26).

2. The apparatus according to claim 1, characterized in that, The first pump (22) and the second pump (26) are of the same type, specifically centrifugal pumps.

3. The apparatus according to claim 1 or 2, characterized in that, The flow diameter of the bypass pipe (20) is basically the same as that of the first pipe (12) and the second pipe (16).

4. The apparatus according to claim 1 or 2, characterized in that, The flow diameter of the bypass pipe (20) is significantly smaller than that of the first pipe (12) and the second pipe (16).

5. The apparatus according to any one of claims 1 to 4, wherein, The control device (54) communicates with at least one temperature sensor (56) that measures the temperature of the element to be cooled (14) and / or the temperature of the cooling fluid in the first pipe (12) after the element to be cooled (14).

6. The apparatus according to claim 5, characterized in that, The control device (54) communicates with exactly one temperature sensor (56) which measures the temperature of the element to be cooled (14) or the temperature of the cooling fluid in the first pipe (12) after the element to be cooled (14).

7. The apparatus according to any one of claims 1 to 6, characterized in that, The fluid connection between the bypass pipeline (20) and the first pipeline (12) and the second pipeline (16) is established by the connection module (40).

8. The apparatus according to claim 7, characterized in that, The connection module (40) includes a first element (42) and a second element (44), which are capable of being mounted on each other and defining an internal bypass conduit (62, 64) and an internal flow channel (58, 60) therebetween for establishing fluid communication between the first conduit (12) and the second conduit (16).

9. A method for controlling flow rate in a cooling circuit, the cooling circuit comprising: The first conduit allows cooling fluid to flow toward and away from the component being cooled. A second conduit, fluidly connected to the first conduit, allows cooling fluid to flow toward and away from the cooling element. A bypass line allows the cooling fluid to bypass the second pipe and circulate within the first pipe. A first pump is used to circulate the cooling fluid in the first pipe, and A second pump is used to circulate the cooling fluid in the second pipe. The method includes controlling the power of the second pump to adjust the amount of cooling fluid flowing through the bypass line.

10. The method according to claim 9, wherein, The first pump operates at a constant power and / or a constant flow rate, and the second pump operates at a variable power based on the desired temperature of the cooling fluid flowing to the element to be cooled.

11. The method according to claim 9 or 10, wherein, The power of the second pump is controlled according to the temperature of the cooling fluid in the first pipe, or the temperature of the component to be cooled, or both.

12. The method according to any one of claims 9 to 11, wherein, The first pump operates at a constant power and / or a constant flow rate.

13. The method according to any one of claims 9 to 12, wherein, The power of the second pump varies based on temperature measurements obtained from at least one temperature sensor.

14. The method according to claim 13, wherein, The at least one temperature sensor measures at least one of the following: — The temperature of the cooling fluid in the first pipe after the element to be cooled, and — The temperature of the component to be cooled.

15. The method according to any one of claims 9 to 14, further comprising: In response to a control signal from a control device configured to adjust the power of the second pump based on the desired temperature of the cooling fluid flowing to the element to be cooled, the second pump is controlled.

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