Design method of water cooling circulation system of optical pumped far infrared laser

Abstract

This application discloses a design method for a water-cooled circulation system of an optically pumped far-infrared laser, including the following steps: identifying the heat sources and generation in the system, compiling a list of components requiring water cooling; drawing a water circuit diagram to confirm the overall water circuit direction and the components to be selected; estimating the heat generated by each part, predicting the total heat load P, determining the overall cooling capacity required by the system, and calculating the overall flow rate G; calculating the cooling water flow rate for the parts of the system that require flow monitoring, and setting up flow controllers. The beneficial effects of this application are: it fully considers and effectively integrates the water cooling requirements of each component in the system, has been verified through application in a system, and can ensure the safe and efficient operation of the device and the laser. The overall layout and component selection have strong reference value and can be used as a reference for the water cooling design of similar systems.

Description

Technical Field

[0001] This application belongs to the field of optically pumped far-infrared laser technology, specifically relating to a design method for a water-cooling circulation system of an optically pumped far-infrared laser. Background Technology

[0002] Optically pumped far-infrared lasers convert the energy of the pump light into the output of the far-infrared laser. Submillimeter-wave optically pumped far-infrared lasers typically use carbon dioxide lasers as their pump source. During laser operation, several system components require cooling. First, in carbon dioxide lasers, gas discharge generates a large amount of heat because the laser's input electrical energy is usually very high. However, most of this energy is used to maintain the gas discharge and increase the gas's average kinetic energy, essentially heating the gas itself. Only a small portion of the energy is used to effectively excite the upper laser level. To maintain laser generation and stable operation, the laser must be cooled. Second, for far-infrared lasers, the gain medium and cavity mirrors absorb energy and generate a large amount of heat. Heat accumulation can lead to wavelength drift, power loss, device damage, and reduced lifespan. Therefore, cooling is also necessary to maintain reliable laser operation. Water cooling is the primary cooling method for high-power lasers due to its high efficiency, uniformity, and high temperature control precision.

[0003] The reliability of the water cooling system is crucial for the efficient operation of lasers. Insufficient cooling will lead to the continuous accumulation of waste heat, resulting in comprehensive performance degradation of the laser (such as power reduction, beam quality collapse, and wavelength drift), and accelerated aging of optical and mechanical components, potentially causing catastrophic damage. Excessive cooling, on the other hand, wastes energy and increases the risk of condensation. Therefore, the reliable operation of the water cooling system is an indispensable core condition for ensuring the efficient, stable, and long-life operation of lasers.

[0004] In the design of the water cooling system, it is necessary to sort out the water cooling requirements of each component inside the laser and make an overall plan for the water cooling circulation system to avoid interference between water, optical and gas paths, which could affect the normal operation of the laser. At the same time, flow controllers need to be installed in the water loops containing key components such as the carbon dioxide laser. The flow controllers are often connected to the safety interlock mechanism of the laser system. When the water flow is less than the preset value, the circuit cannot be turned on and the laser will remain in the off state. Therefore, it can avoid water cooling failure caused by human error, water chiller failure, etc., which could lead to device damage or even threats to personal safety, thus ensuring the safe operation of the laser. Summary of the Invention

[0005] The purpose of this application is to provide a design method for a water-cooling circulation system of an optically pumped far-infrared laser, which solves the problem of how to scientifically and rationally design a water-cooling circulation system for an optically pumped far-infrared laser.

[0006] This application specifically analyzes the water cooling requirements of various components in an optically pumped far-infrared laser, integrates the various branches of water cooling, and completes the design of a customized multi-loop water cooling circulation system. It also sets up key components such as flow controllers to ensure heat dissipation performance while guaranteeing the long-term stable, safe, and efficient operation of the laser. At the same time, it provides the selection criteria for the components.

[0007] The objective of this application is achieved through the following technical solution: A design method for a water-cooling circulation system of an optically pumped far-infrared laser includes the following steps: The first step is to identify the sources and generation of heat in the system and compile a list of components that require water cooling. The second step is to draw a waterway diagram to confirm the overall waterway route and the components that need to be selected. The third step is to estimate the heat generated by each part, predict the total heat load P, determine the overall cooling capacity required by the system, and calculate the overall flow rate G. The fourth step is to calculate the cooling water flow rate for the parts of the system that require flow monitoring and to set up flow controllers.

[0008] Furthermore, the first step: The components in the system that require water cooling include: the carbon dioxide laser cavity, the far-infrared laser cavity, and the two cavity mirrors of the far-infrared laser; The components required for circulation in the system include: a water chiller, which is the core of the water cooling system and provides cooling water; a water distribution drain, which is used to divide the main water circuit into multiple branches; and ball valves, which are used to control the total water volume and switch on / off in the water circuit.

[0009] Further, the second step is to sort out the relative positional relationships between the system and components and draw the water circuit diagram. The water circuit is divided into 4 branches, namely the carbon dioxide laser branch, the far-infrared laser branch, the first far-infrared cavity mirror branch, and the second far-infrared cavity mirror branch. Each branch forms an independent circulation and is divided or integrated by the water distribution drain.

[0010] Furthermore, the second step involves adding a bypass water system at the outlet of the water chiller to regulate the total water flow while ensuring the safe operation of the water chiller. A bypass pipe with a valve is connected between the outlet and return port of the water chiller. When the water consumption at the end decreases and the pressure difference between the supply and return water mains exceeds the set value, some water flows back directly through the bypass pipe, thereby maintaining the minimum flow rate of the water pump and the stability of the system pressure.

[0011] Furthermore, the third step: The calculation method is as follows: Flow rate G ≈ Total heat load P * 14.3 / T and G are in L / min, and P is in kW. T represents the temperature difference, measured in °C.

[0012] Furthermore, T is set at 5℃.

[0013] Furthermore, in the third step: the pipe diameter of some pipelines in the system is a fixed value, while the other branches are designed according to the fixed pipe diameter and the cooling capacity requirements of the branch.

[0014] Furthermore, in the third step: the heat in the carbon dioxide laser branch is obtained from the input electrical power; the heat in the far-infrared laser branch is obtained from the absorption of the pump light output by the carbon dioxide laser within the laser cavity; the heat in the first and second far-infrared cavity mirror branches is obtained by multiplying the laser power received by the absorption rate of the cavity mirror for the laser.

[0015] Furthermore, in the third step: the inner diameter of the output pipe of the water chiller and the inner diameter of the pipe of the carbon dioxide laser branch are fixed values. Based on the fixed pipe diameter size and the cooling requirements of the far-infrared laser branch, the first far-infrared cavity mirror branch and the second far-infrared cavity mirror branch, the pipe diameter size of the far-infrared laser branch, the first far-infrared cavity mirror branch and the second far-infrared cavity mirror branch is designed.

[0016] Furthermore, in the fourth step: flow controllers need to be installed in the carbon dioxide laser branch and the far-infrared laser branch. The minimum water flow rate of the carbon dioxide laser branch and the far-infrared laser branch needs to be calculated, and a flow controller with a higher flow rate than the minimum water flow rate needs to be selected.

[0017] The beneficial effects of this application are: it fully considers and effectively integrates the water cooling requirements of each component in the system, and has been verified through application in the system, ensuring the safe and efficient operation of the devices and laser. The overall layout and component selection are highly instructive and can serve as a reference for the water cooling design of similar systems.

[0018] The aforementioned main solution and its various further alternatives can be freely combined to form multiple solutions, all of which are solutions that can be adopted and are claimed in this application; furthermore, the (non-conflicting alternatives) can also be freely combined with each other and with other alternatives. Those skilled in the art, after understanding the solution of this application, will realize from the prior art and common general knowledge that there are many combinations, all of which are technical solutions to be protected by this application, and will not be exhaustively listed here. Attached Figure Description

[0019] Figure 1 This is a design schematic diagram of this application.

[0020] In the diagram: 1-Bypass water system, 2-Ball valve, 3-Water drain, 4-Carbon dioxide laser branch flow controller, 5-Far-infrared laser branch flow controller, 6-First far-infrared cavity mirror, 7-Second far-infrared cavity mirror. Detailed Implementation

[0021] The following non-limiting embodiments are used to illustrate this application.

[0022] Example 1 A design method for a water-cooled circulation system of an optically pumped far-infrared laser is presented. The method outlines the components and water cooling requirements that need to be considered during the design process. Multiple water circulation branches are integrated into a complete water circulation system. Key components such as water distributors and flow controllers are used in the system to simplify the water circuit and ensure safe system operation.

[0023] The design method includes the following steps: First, identify the sources and generation of heat in the system and compile a list of components that require water cooling.

[0024] The components requiring water cooling in the system include: the carbon dioxide laser cavity, the far-infrared laser cavity, and the two cavity mirrors of the far-infrared laser (first far-infrared cavity mirror 6 and second far-infrared cavity mirror 7); the components required for circulation in the system include: a water chiller, which is the core of the water cooling system and provides cooling water; a water distribution drain 3, which is used to divide the main water circuit into multiple branches, and has the characteristics of high installability and reliability; and a ball valve 2, which is used to control the total water volume and switch on / off in the water circuit.

[0025] The second step is to draw a waterway diagram to confirm the overall waterway route and the components that need to be selected.

[0026] Determine the relative positions of the system and its components, and draw a waterway diagram. (Reference) Figure 1 As shown, the water system is divided into four branches: the carbon dioxide laser branch, the far-infrared laser branch, the first far-infrared cavity mirror branch, and the second far-infrared cavity mirror branch. Each branch forms an independent circulation, and the water is diverted or integrated by the water distribution drain.

[0027] A bypass water system 1 is added at the outlet of the water chiller to regulate the total water flow and ensure the safe operation of the water chiller. A bypass pipe with a valve is connected between the outlet and return port of the water chiller. When the water consumption at the end decreases and the pressure difference between the supply and return water mains exceeds the set value, part of the water flow will flow back directly through the bypass pipe, thereby maintaining the minimum flow rate of the water pump and the stability of the system pressure.

[0028] The third step is to estimate the heat generated by each part, predict the total heat load P, determine the overall cooling capacity required by the system, and calculate the overall flow rate G.

[0029] The calculation method is: Flow rate G ≈ Total heat load P * 14.3 / T and G are in L / min, and P is in kW. T represents the temperature difference, expressed in degrees Celsius (°C). T is set at 5℃.

[0030] The pipe diameter of some parts of the system is fixed, while the other branches are designed based on the fixed pipe diameter and the cooling capacity requirements of each branch. The water flow rate and pipe diameter directly determine the flow velocity in each branch. For branches with higher water cooling requirements, the flow rate should be increased to ensure the cooling effect, so larger pipes need to be selected.

[0031] The heat generated in the carbon dioxide laser branch is obtained from the input electrical power, approximately 1.5 kW. In the far-infrared laser branch, heat is generated by the absorption of the pump light output from the carbon dioxide laser within the laser cavity, approximately on the order of 0.1 kW. The heat generated in the first and second far-infrared cavity mirror branches is generated by multiplying the laser power received by the cavity mirror's absorptivity. The laser power is approximately on the order of 0.1 kW, and the cavity mirror's absorptivity is extremely low, approximately 0.025%, resulting in a power of approximately 0.03 W. The total cooling power of the system is approximately 1.7 kW, and the total flow rate requirement is approximately 4.86 L / min.

[0032] The inner diameters of the water chiller's output pipe and the carbon dioxide laser branch's pipe are fixed values. The water chiller's output pipe has an inner diameter of 12.7 mm, and the carbon dioxide laser's water pipe has an inner diameter of 6.5 mm. Based on the fixed pipe diameters and the cooling requirements of the far-infrared laser branch, the first far-infrared cavity mirror branch, and the second far-infrared cavity mirror branch, the pipe diameters for these three branches are designed. The inner diameter of the water pipe for the far-infrared laser branch is set to 4.32 mm, and the inner diameter of the water pipe for the cavity mirror branch is set to 2.5 mm.

[0033] The fourth step is to calculate the cooling water flow rate for the parts of the system that require flow monitoring and to set up flow controllers.

[0034] Flow controllers are required in both the carbon dioxide laser branch and the far-infrared laser branch, specifically flow controller 4 for the carbon dioxide laser branch and flow controller 5 for the far-infrared laser branch, as the operation of these two branches is closely related to the safe operation of the lasers. The minimum water flow rates for the carbon dioxide laser branch and the far-infrared laser branch are calculated to be 4.29 L / min and 0.286 L / min respectively, necessitating the selection of flow controllers with flow rates higher than these minimums.

[0035] The foregoing basic examples and their further alternative examples can be freely combined to form multiple embodiments, all of which are embodiments that can be adopted and claimed in this application. In the scheme of this application, each alternative example can be arbitrarily combined with any other basic example and alternative example.

[0036] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A design method for a water-cooling circulation system of an optically pumped far-infrared laser, characterized in that, Includes the following steps: The first step is to identify the sources and generation of heat in the system and compile a list of components that require water cooling. The second step is to draw a waterway diagram to confirm the overall waterway route and the components that need to be selected. The third step is to estimate the heat generated by each part, predict the total heat load P, determine the overall cooling capacity required by the system, and calculate the overall flow rate G. The fourth step is to calculate the cooling water flow rate for the parts of the system that require flow monitoring and to set up flow controllers.

2. The design method for the water-cooling circulation system of the optically pumped far-infrared laser according to claim 1, characterized in that: Step 1: The components in the system that require water cooling include: the carbon dioxide laser cavity, the far-infrared laser cavity, and the two cavity mirrors of the far-infrared laser; the components required for circulation in the system include: a water chiller, which is the core of the water cooling system and provides cooling water; a water distribution drain, which is used to divide the main water circuit into multiple branches; and ball valves, which are used to control the total water volume and switch on / off in the water circuit.

3. The design method for the water-cooling circulation system of the optically pumped far-infrared laser according to claim 2, characterized in that: Step 2: Analyze the relative positions of the system and components and draw the water circuit diagram. The water circuit is divided into 4 branches: the carbon dioxide laser branch, the far-infrared laser branch, the first far-infrared cavity mirror branch, and the second far-infrared cavity mirror branch. Each branch forms an independent circulation and is divided or integrated by the water distribution drain.

4. The design method for the water-cooling circulation system of the optically pumped far-infrared laser according to claim 3, characterized in that: Step 2: Add a bypass water system at the outlet of the water chiller to regulate the total water flow and ensure the safe operation of the water chiller. Connect a bypass pipe with a valve between the outlet and return port of the water chiller. When the water consumption at the end decreases and the pressure difference between the supply and return water mains exceeds the set value, some water flows back directly through the bypass pipe, thereby maintaining the minimum flow rate of the water pump and the stability of the system pressure.

5. The design method for the water-cooling circulation system of the optically pumped far-infrared laser according to claim 1, characterized in that: Step 3: The calculation method is: Flow rate G ≈ Total heat load P * 14.3 / T and G are in L / min, and P is in kW. T represents the temperature difference, measured in °C.

6. The design method for the water-cooling circulation system of the optically pumped far-infrared laser according to claim 5, characterized in that: T is set at 5℃.

7. The design method for the water-cooling circulation system of the optically pumped far-infrared laser according to claim 5, characterized in that: Step 3: The pipe diameter of some pipes in the system is a fixed value, while the other branches are designed according to the fixed pipe diameter and the cooling capacity requirements of the branch.

8. The design method for a water-cooled circulation system of an optically pumped far-infrared laser according to claim 1 or 5, characterized in that: Step 3: The heat in the carbon dioxide laser branch is obtained from the input electrical power; the heat in the far-infrared laser branch is obtained from the absorption of the pump light output by the carbon dioxide laser within the laser cavity; the heat in the first and second far-infrared cavity mirror branches is obtained by multiplying the laser power it receives by the absorption rate of the laser by the cavity mirror.

9. The design method for the water-cooling circulation system of the optically pumped far-infrared laser according to claim 8, characterized in that: Step 3: The inner diameter of the output pipe of the water chiller and the inner diameter of the pipe of the carbon dioxide laser branch are fixed values. Based on the fixed pipe diameter size and the cooling requirements of the far-infrared laser branch, the first far-infrared cavity mirror branch and the second far-infrared cavity mirror branch, the pipe diameter size of the far-infrared laser branch, the first far-infrared cavity mirror branch and the second far-infrared cavity mirror branch is designed.

10. The design method for the water-cooling circulation system of the optically pumped far-infrared laser according to claim 1, characterized in that: Step 4: Flow controllers need to be installed in the carbon dioxide laser branch and the far-infrared laser branch. Calculate the minimum water flow rate of the carbon dioxide laser branch and the far-infrared laser branch, and select a flow controller with a flow rate higher than the minimum water flow rate.

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