Pulse tube refrigeration device based on semiconductor refrigeration ring

Abstract

The invention discloses a pulse tube refrigeration device based on a semiconductor refrigeration ring. The device comprises a compressor, a precooler, a heat regenerator, a cold-end heat exchanger, a pulse tube, a hot-end heat exchanger, a reducing cavity, an adjusting tube and an air reservoir which are communicated in sequence. The semiconductor refrigeration sleeve is arranged outside the heat regenerator, and the surfaces of the semiconductor refrigeration sleeve and the heat regenerator are tightly attached. The semiconductor refrigeration sleeve is formed by overlapping a plurality of annular semiconductor refrigeration sheets, the hot surface of each semiconductor refrigeration sheet faces upwards, the cold surface of each semiconductor refrigeration sheet faces downwards, and the cold and hot surfaces of every two adjacent semiconductor refrigeration sheets are connected through heat-conducting silicone grease. Temperature sensors are arranged at the top and the bottom of the semiconductor refrigeration sleeve to monitor the temperature difference in real time, and the control system adjusts the input current of the semiconductor refrigeration piece and adjusts the refrigeration power of the semiconductor refrigeration piece. Through the stacked structure of the semiconductor refrigeration rings, step-by-step reduction of the temperature is achieved, the cooling efficiency is remarkably improved, and accurate temperature control can be conducted. The device is compact in structure, high in reliability and suitable for the working environment with the high requirement for equipment stability.

Description

Technical Field

[0001] This invention belongs to the field of refrigeration technology, especially the field of high-frequency pulse tube cryogenic refrigerators, and specifically relates to a refrigeration device based on a semiconductor refrigeration ring pulse tube. Background Technology

[0002] With the rapid advancement of science and technology, the demand for stable and efficient low-temperature environments is becoming increasingly urgent in cutting-edge fields such as superconductivity, cryogenic electronics, space exploration, biomedical preservation and analysis, and quantum computing. This places extremely high demands on the temperature stability, control precision, and reliability of refrigeration systems. Traditional refrigeration technologies, such as GM refrigerators or Stirling refrigerators based on compression-expansion cycles, can achieve low temperatures, but their core moving parts (exhaustors, pistons) inevitably cause vibration, wear, lubricant contamination, and reliability issues, which become significant problems in many high-precision applications. Furthermore, these systems are often complex in structure, expensive, and their efficiency drops significantly when pursuing extremely low temperatures (such as below 20K).

[0003] Semiconductor cooling devices (TECs), based on the Peltier effect, occupy an important position in applications with low cooling capacity requirements, extremely limited space, or extremely high reliability requirements (such as laser temperature control, localized cooling of electronic chips, portable refrigerators, and temperature control of satellite sensors) due to their all-solid-state structure, absence of any moving mechanical parts, lack of working medium, zero vibration and noise during operation, long lifespan, fast response speed (down to milliseconds), and unique advantages such as seamless switching between cooling and heating modes by simply changing the direction of current. However, their core bottleneck lies in the limitation of material properties; the maximum effective temperature difference that a single-stage TEC can establish is typically only around 65-70°C. Even with multi-stage cascading technology, although the temperature can be further reduced, the system efficiency decreases exponentially, and the total amount of waste heat dissipated from the hot end is enormous, making heat dissipation an extremely difficult problem. This greatly limits their application in scenarios requiring large temperature differences and high cooling capacity.

[0004] As a prominent example of regenerative cryogenic refrigerators, pulse tube refrigerators ingeniously eliminate the moving parts (exhaust devices) at the cold end of traditional refrigerators, achieving cooling solely through the oscillation of pressure waves within a hollow tube. This revolutionary design endows it with a series of outstanding advantages, including relatively simple structure, extremely high operational reliability, long theoretical lifespan, virtually no vibration, and no oil contamination, demonstrating enormous application potential in fields such as space applications and ground-based superconducting cooling. However, further breakthroughs in its performance also face severe challenges: First, in the extremely low temperature range (especially below 20K), the efficiency of the cold-end heat exchanger becomes a major limiting factor due to changes in the properties of the helium working fluid; second, internal thermoacoustic instability and DC effects are difficult to completely eliminate; third, how to further optimize the regenerator packing (e.g., using magnetic cold storage materials such as Er3Ni and HoCu2) to improve its cryogenic heat capacity, and how to precisely coordinate the phase relationship between the pressure wave generator and the pipeline to maximize cooling efficiency, remain current research difficulties.

[0005] Therefore, in the face of the above challenges, exploring an innovative hybrid refrigeration architecture that organically combines the advantages of semiconductor refrigeration chips in the near-room temperature range with the advantages of pulse tube refrigerators in the deep cryogenic range in the high efficiency and high reliability range, in order to construct a new type of high-efficiency, low-temperature, low-vibration composite refrigeration system, has become a highly attractive research direction for breaking through current technical bottlenecks and a key engineering problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a semiconductor cooling ring pulse tube cooling device. Through a unique semiconductor cooling ring superposition structure and an innovative connection method with the pulse tube refrigerator, the cooling efficiency of the cooling system is significantly improved, enabling the rapid acquisition of lower temperature environments to meet the stringent requirements of different fields for low-temperature environments.

[0007] The present invention comprises a compressor, a precooler, a regenerator, a cold-end heat exchanger, a pulse tube, a hot-end heat exchanger, a converging chamber, a regulating pipe, and a gas storage unit, connected in sequence. The high-temperature and high-pressure gas compressed by the compressor enters the regenerator through the precooler, where it is further cooled and absorbs heat from the cold-end heat exchanger. Then it enters the pulse tube, where the temperature at the hot end of the pulse tube rises. After passing through the hot-end heat exchanger, the gas undergoes heat exchange again. After passing through the converging chamber, it enters the gas storage unit through the regulating pipe, which is equipped with a regulating valve to regulate the gas flow rate.

[0008] The cylindrical regenerator is provided with a semiconductor refrigeration sleeve, the inner wall of which is tightly attached to the surface of the regenerator and fixed with thermally conductive adhesive.

[0009] The semiconductor cooling sleeve is composed of multiple annular semiconductor cooling chips stacked together, with the hot side of each semiconductor cooling chip facing upwards and the cold side facing downwards. The hot and cold sides of two adjacent semiconductor cooling chips are connected by thermally conductive silicone grease.

[0010] Temperature sensors are installed at the top and bottom of the semiconductor cooling sleeve to monitor the temperature difference in real time. The monitoring data is fed back to the control system, which adjusts the input current of the semiconductor cooling chip to adjust its cooling power.

[0011] The beneficial effects of this invention include:

[0012] Significantly improved cooling efficiency: Through the stacked structure of semiconductor cooling rings, a step-by-step temperature reduction is achieved. Each additional semiconductor cooling element increases the temperature difference by approximately 35K, significantly improving the cooling temperature difference compared to traditional single-stage semiconductor refrigeration. Simultaneously, in conjunction with the pulse tube refrigerator regenerator, the cooling advantages of both are fully utilized, achieving complementary strengths and further accelerating the cooling rate, enabling the system to reach the target low-temperature environment in a shorter time.

[0013] Precise temperature control: The intelligent control system can accurately adjust the input current of the semiconductor cooling chip based on real-time temperature data through a PID control algorithm, thereby achieving precise control of the cooling power. This allows the system to stably maintain the temperature within the set range, with a temperature control accuracy of ±0.5K, meeting the needs of application scenarios with extremely high temperature accuracy requirements.

[0014] Compact structure and high reliability: The semiconductor refrigeration chip itself has no moving mechanical parts, and the stacked structure and connection method with the pulse tube refrigeration machine make the entire device compact and space-saving. At the same time, it reduces the complex mechanical parts in traditional refrigeration systems, lowers the probability of equipment failure, and improves the reliability and stability of the system, making it suitable for various working environments with high requirements for equipment stability.

[0015] Energy-saving and environmentally friendly: Semiconductor cooling chips do not use refrigerants during operation, avoiding refrigerant pollution. Furthermore, through precise temperature control and a highly efficient heat dissipation system, they effectively reduce energy consumption and improve energy efficiency, aligning with current trends in energy conservation and environmental protection. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0017] Figure 2 This is a schematic diagram of a semiconductor cooling sleeve structure;

[0018] Figure 3 This is a schematic diagram of a semiconductor cooling chip. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0020] like Figure 1 As shown, the semiconductor refrigeration ring pulse tube refrigeration device includes a compressor 1, a precooler 2, a regenerator 3, a cold end heat exchanger 4, a pulse tube 5, a hot end heat exchanger 6, a shrinking chamber 7, a regulating pipe 8, and a gas reservoir 9 connected in sequence.

[0021] The converging cavity 7 is an inverted trumpet-shaped cavity with a smooth curved inner wall. The upper end of the converging cavity 7 is connected to the gas storage 9 via the regulating pipe 8, and the lower end of the converging cavity is connected to the hot-end heat exchanger 6. The high-temperature and high-pressure gas compressed by the compressor 1 passes through the precooler 2 and enters the regenerator 3. After being further cooled by the regenerator 3, it absorbs heat from the cold-end heat exchanger 4 and then enters the pulse tube 5. The temperature at the hot end of the pulse tube 5 increases, and the gas undergoes heat exchange again after passing through the hot-end heat exchanger 6. After that, it passes through the converging cavity 7 and enters the gas storage 9 through the regulating pipe 8. The regulating pipe 8 is equipped with a regulating valve, which is used to regulate the gas flow.

[0022] A semiconductor cooling sleeve 10 is provided outside the cylindrical regenerator 3. The inner wall of the semiconductor cooling sleeve 10 is tightly attached to the surface of the regenerator 3 and fixed with thermally conductive adhesive. The thermal conductivity of the thermally conductive adhesive is greater than or equal to 4 W / (m·K) to achieve efficient heat exchange.

[0023] like Figure 2 and 3 As shown, the thermoelectric cooling sleeve 10 is composed of multiple stacked annular thermoelectric cooling chips 11, with the hot side of each chip facing upwards and the cold side facing downwards. The hot and cold sides of two adjacent thermoelectric cooling chips 11 are connected by thermally conductive silicone grease 12, which has a thickness of 1-2 mm to enhance heat conduction and uniform distribution. The thermoelectric cooling chips have an inner diameter of 15-25 mm, an outer diameter of 25-35 mm, and a height of 3-6 mm. In this embodiment, a thermoelectric cooling chip with an inner diameter of 10 mm, an outer diameter of 20 mm, and a height of 5 mm, model TEC1-12706, is used, with a rated voltage of 12V and a maximum cooling power of 60W. The thermoelectric cooling chips 11 are fixed by the thermally conductive silicone grease 12 to reduce thermal resistance and improve heat transfer efficiency.

[0024] Each thermoelectric cooler generates a temperature difference through its internal Peltier effect after being powered on. For example, the hot side temperature of the first thermoelectric cooler is set to 300K and the cold side temperature to 265K; the hot side temperature of the second thermoelectric cooler is set to 265K and the cold side temperature to 230K; the hot side temperature of the third thermoelectric cooler is set to 230K and the cold side temperature to 195K, and so on. By gradually reducing the temperature in this way, the cold side temperature of the last thermoelectric cooler can be reduced to 20K.

[0025] An intelligent control system is constructed, including temperature sensors, a controller, and a power driver. The temperature sensors are responsible for collecting temperature data of the cold and hot surfaces of the thermoelectric coolers and the temperature data of the cold-end heat exchanger of the pulse tube refrigerator. The power driver is connected to each thermoelectric cooler, and the current regulation accuracy of the power driver is ±0.01A to ensure that the thermoelectric coolers can operate stably and efficiently.

[0026] Temperature sensors are installed at the top and bottom of the semiconductor cooling sleeve 10 to monitor the temperature difference between them in real time. The temperature sensors have an accuracy of ±0.1K and feed the monitoring data back to the control system. The control system adjusts the input current of the semiconductor cooling chip, thereby adjusting its cooling power and achieving precise control of the cooling process.

[0027] The controller employs a microprocessor. Based on the preset temperature target and the collected temperature data, it calculates the required input current value for the thermoelectric cooler using a PID control algorithm (a conventional algorithm) and sends the control signal to the power driver. The power driver, following the controller's instructions, precisely adjusts the magnitude and direction of the current input to the thermoelectric cooler, achieving precise control of the cooler's cooling power.

Claims

1. A semiconductor refrigeration ring pulse tube refrigeration device, comprising a compressor, a precooler, a regenerator, a cold-end heat exchanger, a pulse tube, a hot-end heat exchanger, a converging chamber, a regulating pipe, and a gas storage unit connected in sequence; the high-temperature, high-pressure gas compressed by the compressor enters the regenerator after passing through the precooler, where it is further cooled and absorbs heat from the cold-end heat exchanger, then enters the pulse tube, where the temperature at the hot end of the pulse tube rises. The gas then passes through the hot-end heat exchanger for further heat exchange, and then passes through the converging chamber and the regulating pipe into the gas storage unit. The regulating pipe is equipped with a regulating valve to regulate the gas flow rate; characterized in that: The cylindrical regenerator is provided with a semiconductor refrigeration sleeve, the inner wall of the semiconductor refrigeration sleeve is tightly attached to the surface of the regenerator and fixed with thermally conductive adhesive; The semiconductor cooling sleeve is composed of multiple annular semiconductor cooling chips stacked together, with the hot side of each semiconductor cooling chip facing up and the cold side facing down. The hot and cold sides of two adjacent semiconductor cooling chips are connected by thermally conductive silicone grease. Temperature sensors are installed at the top and bottom of the semiconductor cooling sleeve to monitor the temperature difference in real time. The monitoring data is fed back to the control system, which adjusts the input current of the semiconductor cooling chip to adjust its cooling power.

2. The semiconductor cooling ring pulse tube cooling device as described in claim 1, characterized in that: The converging cavity is an inverted trumpet-shaped cavity with a smooth curved inner wall. The upper end of the converging cavity is connected to the gas reservoir through an adjustment pipe, and the lower end of the converging cavity is connected to the hot end heat exchanger.

3. The semiconductor cooling ring pulse tube cooling device as described in claim 1, characterized in that: The semiconductor cooling chip has an inner diameter of 15-25 mm, an outer diameter of 25-35 mm, and a height of 3-6 mm.

4. The semiconductor cooling ring pulse tube cooling device as described in claim 1, characterized in that: The thickness of the thermal grease layer is 1-2 mm.

5. The semiconductor cooling ring pulse tube cooling device as described in claim 1, characterized in that: The thermal conductivity of the thermally conductive adhesive is greater than or equal to 4 W / (m·K).

6. The semiconductor cooling ring pulse tube cooling device as described in claim 1, characterized in that: The control system includes a controller and a power driver. The controller uses a microprocessor to calculate the required input current value of the thermoelectric cooler based on the preset temperature target and the collected temperature data, and sends the control signal to the power driver. The power driver is connected to each thermoelectric cooler and adjusts the magnitude and direction of the current input to the thermoelectric cooler according to the controller's instructions.

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