Portable radiation dosimeter cooling method and portable radiation dosimeter

Abstract

The invention discloses a portable radiation dosimeter cooling method and a portable radiation dosimeter, and relates to the technical field of radiation dosimeters. The method comprises the steps that based on the heat conduction effect, a radiator conducts heat generated by a linear power supply to the surface of the radiator for preliminary heat dissipation; the wire is connected with the thermoelectric power generation module, the DC-DC converter and the semiconductor chilling plate to form a power supply loop; the surface temperature of the radiator is monitored through a temperature sensor, and a power supply loop is switched on when the surface temperature of the radiator exceeds a temperature threshold; when the power supply loop is conducted, the thermoelectric power generation module converts waste heat into electric energy; the electric energy is transmitted to the semiconductor chilling plate through the DC-DC converter to drive the semiconductor chilling plate to start and act on the radiator to accelerate cooling. Through the design of the power supply loop, waste heat generated in the operation process of the portable radiation dosimeter is recycled, the heat dissipation effect and the energy utilization rate are enhanced, and the stability of the portable radiation dosimeter system is improved.

Description

Technical Field

[0001] This application relates to the field of radiation dosimeter technology, and in particular to a cooling method for a portable radiation dosimeter and a portable radiation dosimeter. Background Technology

[0002] A portable radiation dosimeter is a handy device for detecting radiation dose. It provides radiation dose information in various scenarios, measuring ambient gamma / X-ray dose rate and cumulative dose in real time, and triggering audible / visual / vibration alarms when radiation levels exceed limits. The power supply system of a portable radiation dosimeter is a crucial component for ensuring stable operation, typically requiring high efficiency, stability, low power consumption, and miniaturization. Based on topology, common portable radiation dosimeter power supplies include switching power supplies and linear power supplies. Switching power supply topologies control the on / off state of power transistors to chop the input voltage into high-frequency pulses, which are then filtered and rectified to obtain a stable output voltage. Linear power supply topologies, on the other hand, utilize linear regulators (LDOs) to continuously control the conduction level of power transistors, adjusting the input voltage to a stable output voltage.

[0003] Linear power supply topologies are simple, have low output voltage ripple, and low electromagnetic interference, providing a stable and clean energy source for radiation dosimeters. However, the power transistors inside the linear power supply consume a significant amount of energy during voltage regulation, which is typically dissipated as heat, increasing system power consumption, causing the device to overheat, and consequently affecting system stability and reliability. Therefore, it is necessary to optimize the heat dissipation methods of the linear power supply topology for radiation dosimeters to improve system stability. Currently, conventional heat dissipation methods for portable radiation dosimeter linear power supplies mainly involve the following: 1. Use materials with high thermal conductivity such as copper and aluminum to make heat sinks or fins to reduce the resistance to heat conduction from heat-generating elements to heat dissipation surfaces; design fins or microchannels on the surface of the heat sink to improve heat dissipation efficiency by increasing the contact area with air.

[0004] 2. Place the heat-generating components at the edge of the radiation dosimeter so that the heat can be carried away by airflow.

[0005] It is evident that the existing methods are passive heat dissipation methods, with heat dissipation efficiency being highly constrained by the environment and lacking proactive ways to improve heat dissipation efficiency. Moreover, the direct dissipation of lost heat energy also results in low energy utilization of the equipment. Summary of the Invention

[0006] This application provides a cooling method for a portable radiation dosimeter and a portable radiation dosimeter to solve the problems in the prior art.

[0007] On one hand, embodiments of this application provide a cooling method for a portable radiation dosimeter, comprising: Based on thermal conduction, the heat sink conducts the heat generated by the linear power supply of the portable radiation dosimeter to the surface of the heat sink for initial heat dissipation. A power supply circuit is formed by connecting the thermoelectric generator (TEG), the DC-DC converter, and the thermoelectric cooler (TEC) with wires, using the thermoelectric generator as the power input source and the thermoelectric cooler as the load. The surface temperature of the radiator is monitored in real time by a temperature sensor. When the surface temperature of the radiator exceeds the temperature threshold, the power supply circuit is turned on through the DC-DC converter. When the power supply circuit is turned on, the thermoelectric generator module converts the waste heat generated during the heat dissipation process of the linear power supply into electrical energy; the electrical energy is transmitted to the thermoelectric cooler through the DC-DC converter; the thermoelectric cooler is driven to start, and the thermoelectric cooler acts on the heat sink to accelerate the cooling of the heat sink.

[0008] Furthermore, the temperature threshold is set according to the rated operating temperature of the linear power supply.

[0009] On the other hand, this application also provides a portable radiation dosimeter, including: a linear power supply, a heat sink, a thermoelectric generator module, wires, a DC-DC converter, and a semiconductor refrigeration chip; The linear power supply provides energy to the portable radiation dosimeter; a heat sink is placed on top of the linear power supply to dissipate heat; both the thermoelectric generator module and the thermoelectric cooler are placed on the surface of the heat sink; the thermoelectric generator module is used to recover waste heat generated by the linear power supply for power generation; a DC-DC converter is connected to the thermoelectric generator module and the thermoelectric cooler via wires; the DC-DC converter is used to control the on and off of the power supply circuit; and the thermoelectric cooler is used to cool the heat sink.

[0010] Furthermore, the portable radiation dosimeter also includes an external frame made of plastic.

[0011] Furthermore, the radiator is made of aluminum or copper.

[0012] Furthermore, the linear power supply adopts a PNP type LDO, and the DC-DC converter adopts a Buck step-down topology.

[0013] The cooling method for a portable radiation dosimeter and the portable radiation dosimeter disclosed in this application have the following advantages: (1) In view of the shortcomings of the existing methods in passive heat dissipation and heat dissipation efficiency being highly dependent on the environment, this application constructs a synergistic heat dissipation mechanism that combines passive heat conduction and heat dissipation with active cooling enhancement. While the heat sink completes the basic heat conduction, TEC is introduced as an active cooling unit. Even in scenarios with low natural convection heat dissipation efficiency, such as high temperature or enclosed spaces, the heat sink can be actively accelerated to cool down. This greatly eliminates the dependence of traditional passive heat dissipation on environmental conditions and improves the temperature stability of the portable radiation dosimeter under all operating conditions.

[0014] (2) This application uses a temperature sensor in combination with a temperature threshold setting to automatically shut down the circuit, thereby realizing the on-demand adjustment of heat dissipation capacity and solving the technical defect that the heat dissipation capacity of traditional passive heat dissipation is fixed and cannot match load fluctuations.

[0015] (3) This application achieves the reuse of waste heat through the setting of TEG, converting the heat energy that was originally wasted in the process of linear power supply heat dissipation into usable electrical energy, and using it as the power supply for TEC, forming an energy utilization closed loop. It can drive the active cooling unit without consuming additional battery power of the device, which reduces energy loss and extends the battery life of the portable radiation dosimeter, thus improving the overall energy utilization rate of the device. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart illustrating the method provided in this application embodiment.

[0018] Figure 2 Flowchart for heat dissipation of a portable radiation dosimeter.

[0019] Figure 3 This is a schematic diagram of the overall architecture of a PNP-type LDO.

[0020] Figure 4 This is a schematic diagram of a portable radiation dosimeter.

[0021] The following are the symbols and their meanings: 1. External frame; 2. Linear power supply; 3. Heat sink; 4. Thermoelectric generator module; 5. Wire; 6. DC-DC converter; 7. Semiconductor cooling chip. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] Figure 1 This application provides a method flowchart for an embodiment of the present application. This application provides a cooling method for a portable radiation dosimeter, including: Based on thermal conduction, the heat sink 3 conducts the heat generated by the linear power supply 2 of the portable radiation dosimeter to the surface of the heat sink 3 for initial heat dissipation.

[0024] The thermoelectric generator module 4, the DC-DC converter 6, and the thermoelectric cooler 7 are connected by wire 5 to form a power supply circuit with the thermoelectric generator module 4 as the power input source and the thermoelectric cooler 7 as the load.

[0025] The surface temperature of the radiator 3 is monitored in real time by a temperature sensor. When the surface temperature of the radiator 3 exceeds the temperature threshold, the power supply circuit is turned on through the DC-DC converter 6.

[0026] In one possible implementation, the temperature threshold is set according to the rated operating temperature of the linear power supply 2.

[0027] When the power supply circuit is turned on, the thermoelectric generator module 4 converts the waste heat generated during the heat dissipation process of the linear power supply 2 into electrical energy; the electrical energy is transmitted to the thermoelectric cooler 7 through the DC-DC converter 6; the thermoelectric cooler 7 is driven to start, and the thermoelectric cooler 7 acts on the heat sink 3 to accelerate the cooling of the heat sink 3.

[0028] For example, such as Figure 2 The heat dissipation flowchart of the portable radiation dosimeter is shown. The temperature threshold is set to 45℃. During the operation of the portable radiation dosimeter, its linear power supply generates heat. When the temperature sensor detects that the surface temperature of the heat sink exceeds 45℃, the DC-DC converter turns on the power supply circuit. At this time, the TEC (Transmission Controlled Temperature) accelerates the cooling of the heat sink, speeding up the heat dissipation process. When the surface temperature of the heat sink detected by the temperature sensor does not exceed 45℃, the DC-DC converter turns off, and only the heat sink provides initial heat dissipation. This process continues until the temperature sensor detects that the surface temperature of the heat sink exceeds 45℃ again as the linear power supply generates heat, at which point the TEC-assisted cooling process is executed again to accelerate heat dissipation.

[0029] For example, such as Figure 3 The overall architecture diagram of a PNP type LDO is shown as an example. The PNP type LDO uses the input voltage V provided by the battery pack. inProvide power, with output load R load Through PNP transistors Q1 and V in Connected. Resistors R1 and R2 form a voltage sensing network that acquires the LDO's output voltage signal in real time and inputs the detected voltage value into an error amplifier to neutralize the reference voltage V. Ref A comparison is made. The result of the comparison is used to control the NPN transistor Q2. Subsequently, the current from the collector of Q2 flows through the gate of Q1, thereby controlling Q1.

[0030] During the operation of a PNP type LDO, heat is mainly dissipated on Q1. The heat sink is arranged near Q1 so that the heat generated by Q1 can be quickly transferred to the surface of the heat sink through thermal conduction. Then, the heat is initially dissipated through natural convection between the heat sink and the environment, maximizing the heat dissipation effect.

[0031] The heat sink surface temperature threshold is set to 45℃, and the heat sink surface temperature is monitored in real time by a temperature sensor. When the heat sink surface temperature exceeds the set threshold of 45℃, MOSFET Q3 enters the working state, and its duty cycle is set to 50%.

[0032] In the Buck topology of a DC-DC converter, the inductor L and the capacitor C form an LC filter circuit. The filter inductor L is used to suppress current ripple and prevent sudden current changes from impacting the TEC. The filter capacitor C is used to filter out voltage ripple, making the DC power output to the TEC more stable, ensuring the stability of the TEC's cooling performance, and improving the quality of the output power.

[0033] When Q3 is on, TEG, Q3, L, and TEC form a closed loop. D is a freewheeling diode; when Q3 is off, D acts as the conducting circuit, and D, L, and TEG form a closed loop. Through the switching on and off of Q3, TEC continuously cools the circuit during the operating cycle, ultimately ensuring that the surface temperature of the heatsink does not exceed 45°C, thus guaranteeing that the linear power supply remains within its safe operating temperature range.

[0034] When the method proposed in this application is not used, the overall system efficiency is... for:

[0035] in, , These are the system's input power and output power, respectively.

[0036]

[0037] in, The heat dissipation power is the power without using the method described in this application.

[0038] After adopting the method proposed in this application, the system heat dissipation power becomes:

[0039] in, The heat dissipation power after using the method proposed in this application, For the cooling efficiency of the TEC module.

[0040] Therefore, by adopting the method proposed in this application, the heat dissipation power of the system is reduced and the output power ratio is increased, thereby improving the overall efficiency of the system.

[0041] This application embodiment also provides a portable radiation dosimeter, including: a linear power supply 2, a heat sink 3, a thermoelectric generator module 4, a wire 5, a DC-DC converter 6, and a semiconductor cooling chip 7.

[0042] Linear power supply 2 provides an energy source for the portable radiation dosimeter; heat sink 3 is placed on top of linear power supply 2 and is used to dissipate heat from linear power supply 2; thermoelectric generator module 4 and thermoelectric cooler 7 are both placed on the surface of heat sink 3; thermoelectric generator module 4 is used to recover the waste heat generated by linear power supply 2 for power supply; DC-DC converter 6 is connected to thermoelectric generator module 4 and thermoelectric cooler 7 through wire 5; DC-DC converter 6 is used to control the power supply circuit to be turned on and off; thermoelectric cooler 7 is used to cool heat sink 3.

[0043] For example, Figure 4 The diagram shows the structure of a portable radiation dosimeter.

[0044] In one possible implementation, the portable radiation dosimeter also includes an outer frame 1, which is made of plastic.

[0045] In one possible implementation, the heat sink 3 is made of aluminum or copper.

[0046] In one possible implementation, the linear power supply 2 adopts a PNP type LDO, and the DC-DC converter 6 adopts a Buck step-down topology.

[0047] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0048] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A cooling method for a portable radiation dosimeter, characterized in that, include: Based on thermal conduction, the heat sink (3) conducts the heat generated by the linear power supply (2) of the portable radiation dosimeter to the surface of the heat sink (3) for initial heat dissipation; The thermoelectric generator module (4), DC-DC converter (6) and semiconductor refrigeration chip (7) are connected by wire (5) to form a power supply circuit with the thermoelectric generator module (4) as the power input source and the semiconductor refrigeration chip (7) as the load; The surface temperature of the radiator (3) is monitored in real time by a temperature sensor. When the surface temperature of the radiator (3) exceeds the temperature threshold, the power supply circuit is turned on by the DC-DC converter (6). When the power supply circuit is turned on, the thermoelectric generator module (4) converts the waste heat generated during the heat dissipation process of the linear power supply (2) into electrical energy; the electrical energy is transmitted to the thermoelectric cooler (7) through the DC-DC converter (6); the thermoelectric cooler (7) is driven to start, and the thermoelectric cooler (7) acts on the heat sink (3) to accelerate the cooling of the heat sink (3).

2. The cooling method for a portable radiation dosimeter according to claim 1, characterized in that: The temperature threshold is set according to the rated operating temperature of the linear power supply (2).

3. A portable radiation dosimeter, characterized in that, The portable radiation dosimeter is cooled by the method described in any one of claims 1-2, and includes: a linear power supply (2), a heat sink (3), a thermoelectric generator module (4), a wire (5), a DC-DC converter (6), and a semiconductor cooling chip (7); The linear power supply (2) is used to provide an energy source for the portable radiation dosimeter; the heat sink (3) is placed on top of the linear power supply (2) and is used to dissipate heat from the linear power supply (2); the thermoelectric generator module (4) and the thermoelectric cooler (7) are both placed on the surface of the heat sink (3); the thermoelectric generator module (4) is used to recover the waste heat generated by the linear power supply (2) for power supply; the DC-DC converter (6) is connected to the thermoelectric generator module (4) and the thermoelectric cooler (7) through the wire (5); the DC-DC converter (6) is used to control the power supply circuit to be turned on or off; the thermoelectric cooler (7) is used to cool the heat sink (3).

4. A portable radiation dosimeter according to claim 3, characterized in that: The portable radiation dosimeter also includes an external frame (1), which is made of plastic.

5. A portable radiation dosimeter according to claim 3, characterized in that: The radiator (3) is made of aluminum or copper.

6. A portable radiation dosimeter according to claim 3, characterized in that: The linear power supply (2) adopts a PNP type LDO, and the DC-DC converter (6) adopts a Buck step-down topology.

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