Test box with partition temperature control function

Abstract

The utility model discloses a test box with a zoning temperature control function, which comprises a box body, a centrifugal fan is arranged at the air inlet end of the box body, a test chamber is arranged in the box body, the test chamber is divided into a preheating zone, a working zone and a buffer layer along the airflow direction, each zone is provided with an independent temperature control actuator, and the temperature control actuator is connected with the centrifugal fan. The preheating area comprises a liquid nitrogen spraying device arranged at the top of the test chamber and a high-temperature ceramic heating sheet arranged on the side wall of the test chamber, a PTC heating film is embedded in the inner wall of the working area, a micro-channel cold plate is arranged at the bottom of the working area, and the buffer area is provided with a semiconductor chilling plate array and flow guide fins. Transient temperature adjustment is achieved through liquid nitrogen in the preheating area, composite temperature control is achieved through the PTC heating film and the micro-channel cold plate in the working area, temperature fluctuation is dynamically absorbed through the semiconductor chilling plate array in the buffer area, the temperature gradient is formed through one-way airflow, the temperature change rate is increased, and temperature uniformity is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of test chamber technology, and in particular to a test chamber with zoned temperature control function. Background Technology

[0002] High and low temperature alternating humidity and heat test chambers are widely used testing equipment in fields such as national defense, aerospace, automotive, electronics, electrical appliances, instrumentation, materials, chemicals, food, and pharmaceuticals. They are used by users to conduct corresponding high and low temperature gradual change tests, humidity and heat tests, cold and high temperature resistance tests on complete machines (or components), electrical appliances, instruments, materials, coatings, and platings. They are used to analyze and evaluate the performance and adaptability of samples under specific environmental conditions. They are an indispensable and important testing equipment in scientific research and production processes. According to relevant surveys and statistics, high and low temperature humidity and heat test chambers are one of the most widely used environmental testing equipment.

[0003] Conventional test chambers use a single refrigeration / heating system. When the temperature alternates between -40℃ and +150℃, the large thermal inertia results in a slow temperature change rate (typically 3℃ / min), and poor temperature uniformity within the chamber (±2℃). Increasing the compressor power or heating element density will exacerbate stress damage to the inner liner, and a sudden increase in power during temperature changes will lead to circuit aging. Utility Model Content

[0004] To address the aforementioned technical issues, a test chamber with zoned temperature control function is provided.

[0005] To achieve the above objectives, this utility model discloses a test chamber with zoned temperature control function, including a chamber body. A centrifugal fan is installed at the air inlet end of the chamber body. A test chamber is set inside the chamber body. The test chamber is divided into a preheating zone, a working zone, and a buffer zone along the airflow direction. Each zone is equipped with an independent temperature control actuator. The preheating zone includes a liquid nitrogen spray device set at the top of the test chamber and a high-temperature ceramic heating plate set on the side wall of the test chamber. A PTC heating film is embedded in the inner wall of the working zone. A microchannel cold plate is set at the bottom of the working zone. The buffer zone is equipped with a semiconductor refrigeration chip array and a flow guide fin.

[0006] Furthermore, the liquid nitrogen spraying device includes a liquid nitrogen nozzle with a diameter of 0.2 mm. The top of the liquid nitrogen nozzle is fixedly installed on the test chamber through a threaded section and connected to an external liquid nitrogen tank through a safety relief valve.

[0007] Furthermore, the PTC heating film is disposed between the stainless steel inner liner of the test chamber and the aluminum alloy substrate that makes up the chamber. The surface of the PTC heating film near the stainless steel inner liner is provided with laser-etched grooves, and a thermally conductive insulating layer is provided between the PTC heating film and the aluminum alloy substrate.

[0008] Furthermore, the surface of the PTC heating film is divided into independent temperature control units by laser etching a mesh groove structure with a depth of 0.1 mm and a width of 0.3 mm. The resistance value of the PTC heating film is 50 Ω / ㎡.

[0009] Furthermore, the PTC heating film substrate is made of titanium alloy, the PTC heating film thickness is 0.2mm, the stainless steel inner liner thickness is 1mm, and the aluminum alloy substrate thickness is 2mm.

[0010] Furthermore, the guide fins are at a 30° angle to the airflow direction.

[0011] Furthermore, the liquid nitrogen spraying device is controlled by an interlocking circuit with the PTC heating film, and the high-temperature ceramic heating element is controlled by an interlocking circuit with the microchannel cold plate.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model discloses a test chamber with zoned temperature control function. Liquid nitrogen in the preheating zone achieves transient temperature regulation, PTC heating film and microchannel cold plate in the working zone combine to control temperature, semiconductor cooling chip array in the buffer zone dynamically absorbs temperature fluctuations, and temperature gradient is formed by unidirectional airflow to improve the temperature change rate and ensure temperature uniformity. Attached Figure Description

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0014] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0015] Figure 2 This is a schematic diagram of the structure of the PTC heating film of this utility model inside the box.

[0016] Figure 3 This is a front view of the PTC heating film of this utility model.

[0017] Figure 4 This is a schematic diagram of the liquid nitrogen spraying device of this utility model.

[0018] In the diagram: 1 is the housing; 11 is the aluminum alloy substrate; 2 is the preheating zone; 21 is the liquid nitrogen spray device; 211 is the liquid nitrogen nozzle; 212 is the threaded section; 22 is the high-temperature ceramic heating element; 3 is the working area; 30 is the stainless steel inner liner; 31 is the PTC heating film; 311 is the laser-etched groove; 312 is the thermally conductive insulating layer; 32 is the microchannel cold plate; 4 is the buffer zone; 41 is the semiconductor cooling chip array; 42 is the flow guide fins; 5 is the centrifugal fan. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] One embodiment of this utility model is as follows: Figure 1 As shown, a centrifugal fan 5 is installed at the air inlet of chamber 1. The centrifugal fan has a wind pressure of 800 Pa and a frequency conversion range of 5 Hz to 100 Hz. The airflow speed is adjusted as needed to generate unidirectional airflow that forces it through three groups of areas to form a temperature gradient. The chamber 1 contains a test chamber, which is divided into a preheating zone 2, a working zone 3, and a buffer zone 4 along the airflow direction. Each zone is equipped with an independent temperature control actuator. The preheating zone 2 includes a liquid nitrogen spray device 21 installed at the top of the test chamber and high-temperature ceramic heating plates 22 installed on the side wall of the test chamber to precool or preheat the incoming air and achieve instantaneous temperature regulation. A PTC heating film 31 is embedded in the inner wall of the working zone 3, and a microchannel cold plate 32 is installed at the bottom of the working zone 3. Through composite temperature control, the core temperature zone is maintained at ±0.5℃. Within the accuracy range, the buffer zone 4 is equipped with a semiconductor cooling chip array 41 and flow guiding fins 42. The semiconductor cooling chip is model TEC1-12706, with δTmax=68℃ and COP=1.2. It can absorb temperature fluctuations of ±3℃ instantaneously and reduce backflow. The semiconductor cooling chip utilizes the Peltier effect of semiconductor materials. When DC current passes through a coupler composed of two different semiconductor materials connected in series, heat can be absorbed and released at the two ends of the coupler, respectively. Liquid nitrogen in the preheating zone achieves transient temperature regulation. The PTC heating film and microchannel cold plate in the working zone combine to control the temperature. The semiconductor cooling chip array in the buffer zone dynamically absorbs temperature fluctuations and forms a temperature gradient through unidirectional airflow, thereby increasing the temperature change rate and ensuring temperature uniformity. The overall temperature change rate can reach 8.5℃ / min.

[0021] like Figure 2 As shown, the liquid nitrogen spraying device 21 includes a liquid nitrogen nozzle 211 with a diameter of 0.2 mm and a pressure of 1.5 MPa, which shortens the pre-cooling response time. The top of the liquid nitrogen nozzle 211 is fixedly installed on the test chamber through a threaded section 212 and connected to an external liquid nitrogen tank through a safety relief valve to prevent the pipeline from freezing and cracking.

[0022] like Figure 2 As shown, the PTC heating film 31 is disposed between the stainless steel inner liner 30 on the inner wall of the test chamber and the aluminum alloy substrate 11 that makes up the box body 1. The surface of the PTC heating film 31 near the stainless steel inner liner 30 is provided with laser-etched grooves 311, and a thermally conductive insulating layer 312 is provided between the PTC heating film 31 and the aluminum alloy substrate 11.

[0023] like Figure 3 As shown, the surface of the PTC heating film 31 is divided into independent temperature control units by laser etching a mesh groove structure with a depth of 0.1 mm and a width of 0.3 mm. The PTC heating film 31 has a resistance of 50 Ω / ㎡ and a temperature resistance of 200℃, eliminating edge effects in the working area. The substrate of the PTC heating film 31 is made of titanium alloy to improve corrosion resistance. The thickness of the PTC heating film 31 is 0.2 mm, the thickness of the stainless steel inner liner 30 is 1 mm, and the thickness of the aluminum alloy substrate 11 is 2 mm. The laser etching of the PTC film achieves precise temperature control in zones, solving the problem of edge heat dissipation. The temperature change within the 500 mm * 500 mm working area can reach ±0.3℃.

[0024] The guide fins 42 are at a 30° angle to the airflow direction to reduce temperature fluctuations caused by airflow swirl.

[0025] The liquid nitrogen spraying device 21 is interlocked with the PTC heating film 31, and the high-temperature ceramic heating element 22 is interlocked with the microchannel cold plate 32. The interlocking circuit controls the corresponding temperature control actuators to lock each other, thus preventing equipment failure due to temperature conflicts.

[0026] In rapid cooling mode, the temperature needs to be changed from 25℃ to -55℃. The centrifugal fan starts, the airflow enters from the preheating zone, the liquid nitrogen nozzle is turned on, the injection rate is 0.5g / s, the air is precooled to -10℃, the microchannel cold plate in the working area is circulated with -60℃ refrigerant, the PTC heating film is turned off, and the semiconductor cooling chip array in the buffer zone is running at full power. When the temperature sensor in the working area detects that the working area has reached -55℃, the liquid nitrogen injection rate drops to 0.1g / s.

[0027] Under high temperature and high humidity conditions, it is necessary to maintain a constant relative humidity (RH) at +85℃. The centrifugal fan starts, and the airflow enters from the preheating zone. The high-temperature ceramic heating element starts, and the surface temperature is 300℃. The PTC heating film in the working area is powered in zones, and the power density in the edge area is increased by 15% to ensure temperature uniformity. The semiconductor cooling array in the buffer zone is heated in reverse to prevent condensation.

[0028] Several points need to be clarified: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly, and can refer to mechanical or electrical connections, or internal connections between two components, or direct connections. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships, and the relative positional relationships may change when the absolute position of the described objects changes. Second, in this document, relational terms such as "first" and "second" are only used to distinguish one entity from another entity, and do not necessarily require or imply any such actual relationship or order between these entities.

[0029] The above examples are merely illustrative of this utility model and do not constitute a limitation on the scope of protection of this utility model. All designs that are the same as or similar to this utility model are within the scope of protection of this utility model.

Claims

1. A test chamber with zoned temperature control function, comprising a chamber body (1), characterized in that, The air inlet of the chamber (1) is equipped with a centrifugal fan (5). The chamber (1) is equipped with a test chamber. The test chamber is divided into a preheating zone (2), a working zone (3) and a buffer zone (4) along the airflow direction. Each zone is equipped with an independent temperature control actuator. The preheating zone (2) includes a liquid nitrogen spray device (21) set on the top of the test chamber and a high-temperature ceramic heating plate (22) set on the side wall of the test chamber. The inner wall of the working zone (3) is embedded with a PTC heating film (31). The bottom of the working zone (3) is equipped with a microchannel cold plate (32). The buffer zone (4) is equipped with a semiconductor cooling chip array (41) and a flow guide fin (42).

2. A test chamber with zoned temperature control function according to claim 1, characterized in that, The liquid nitrogen spraying device (21) includes a liquid nitrogen nozzle (211) with a diameter of 0.2 mm. The top of the liquid nitrogen nozzle (211) is fixedly installed on the test chamber through a threaded section (212) and connected to an external liquid nitrogen tank through a safety relief valve.

3. A test chamber with zoned temperature control function according to claim 1, characterized in that, The PTC heating film (31) is disposed between the stainless steel inner liner (30) on the inner wall of the test chamber and the aluminum alloy substrate (11) that makes up the box body (1). The PTC heating film (31) has laser-etched grooves (311) on the side surface near the stainless steel inner liner (30), and a thermally conductive insulating layer (312) is disposed between the PTC heating film (31) and the aluminum alloy substrate (11).

4. A test chamber with zoned temperature control function according to claim 3, characterized in that, The PTC heating film (31) is divided into independent temperature control units by laser etching a mesh groove structure with a depth of 0.1 mm and a width of 0.3 mm. The resistance value of the PTC heating film (31) is 50 Ω / ㎡.

5. A test chamber with zoned temperature control function according to claim 4, characterized in that, The PTC heating film (31) substrate is made of titanium alloy, the PTC heating film (31) thickness is 0.2mm, the stainless steel inner liner (30) thickness is 1mm, and the aluminum alloy substrate (11) thickness is 2mm.

6. A test chamber with zoned temperature control function according to claim 1, characterized in that, The guide fins (42) are at a 30° angle to the airflow direction.

7. A test chamber with zoned temperature control function according to claim 1, characterized in that, The liquid nitrogen spraying device (21) is interlocked with the PTC heating film (31) and the high-temperature ceramic heating plate (22) is interlocked with the microchannel cold plate (32).

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