Thử nghiệm mô phỏng môi trường là thử nghiệm để xác minh độ tin cậy chức năng của sản phẩm trong quá trình sử dụng, vận chuyển và lưu trữ. Là để sản phẩm tiếp xúc với các điều kiện môi trường tự nhiên hoặc nhân tạo để trải qua tác động của nó, để đánh giá hiệu suất của sản phẩm trong các điều kiện môi trường thực tế của việc sử dụng, vận chuyển và lưu trữ, đồng thời phân tích và nghiên cứu mức độ ảnh hưởng và cơ chế tác động của các yếu tố môi trường.

Buồng thử nghiệm mô phỏng môi trường là phương pháp để các doanh nghiệp hoặc tổ chức xác minh chất lượng của nguyên liệu thô, bán thành phẩm và thành phẩm trong điều kiện vận chuyển, xử lý, rung động, v.v. Mục đích là để xác minh xem vật liệu và sản phẩm có đáp ứng các mục tiêu chất lượng mong đợi trong R & D, thiết kế và sản xuất hay không bằng cách sử dụng các thiết bị thử nghiệm môi trường khác nhau. Nó được sử dụng rộng rãi trong các trường Cao đẳng và đại học, hàng không, hàng không vũ trụ, quân sự, đóng tàu, thợ điện, điện tử, điều trị y tế, dụng cụ và đồng hồ đo, dụng cụ dầu khí, công nghiệp hóa dầu, điều trị y tế, ô tô và xe máy và các lĩnh vực khác.

Buồng thử nghiệm mô phỏng môi trường có thể thực hiện nhiệt độ cao, nhiệt độ thấp, sốc nhiệt độ (khí và lỏng), ngâm tẩm, chu kỳ nhiệt độ, áp suất thấp, nhiệt độ cao và thấp và áp suất thấp, nhiệt ẩm liên tục, nhiệt ẩm xen kẽ, nấu áp suất cao, bụi cát, chống nổ, ăn mòn phun muối, ăn mòn khí, nấm mốc, mưa, bức xạ mặt trời, lão hóa ánh sáng, v.v. theo IEC, mil, ISO, GB, GJB và các tiêu chuẩn khác hoặc yêu cầu của người dùng.

(1) Thử nghiệm áp suất thấp: thử nghiệm áp dụng cho việc giảm áp suất nhanh chóng của vũ khí được vận chuyển bằng đường hàng không trong khoang hàng của máy bay, vũ khí sử dụng trên cao nguyên và vũ khí trên không sau khi máy bay bị thương. Mục đích của thử nghiệm là kiểm tra hiệu suất phục vụ của vũ khí trong môi trường áp suất thấp và tác động của việc giảm áp suất nhanh chóng đến hiệu suất của vũ khí. Chiều cao tối đa của mô phỏng có thể đạt tới 30000m (m), và giá trị nhiệt độ tương ứng với chiều cao sẽ được lấy trong quá trình thử nghiệm.

(2) Thử nghiệm nhiệt độ cao: trong thử nghiệm, vũ khí ở trong không khí nhiệt độ cao, nhưng không tiếp xúc trực tiếp với ánh sáng mặt trời. Thử nghiệm này nhằm mục đích lưu trữ hoặc sử dụng vũ khí trong nhà hoặc không gian hạn chế hoặc gần các nguồn nhiệt như động cơ trong mùa nhiệt độ cao. Thử nghiệm này chỉ được thực hiện khi thử nghiệm bức xạ mặt trời không thể xác minh tác động của nhiệt độ cao. Mục đích của thử nghiệm là để kiểm tra hiệu suất lưu trữ hoặc sử dụng trong môi trường nhiệt độ cao.

(3) Thử nghiệm nhiệt độ thấp: thử nghiệm này áp dụng cho các mẫu thử có khả năng được sử dụng trong môi trường nhiệt độ thấp trong suốt vòng đời.

(4) Thử nghiệm sốc nhiệt: thử nghiệm này áp dụng cho các loại vũ khí thường xuyên phải chịu những thay đổi nhiệt độ cực nhanh trong khu vực sử dụng hoặc chế độ sử dụng đã định trước. Ví dụ: các silo thiết bị điện tử, tên lửa và thiết bị quang điện tử trên máy bay cất cánh từ sân bay sa mạc và bay lên độ cao lớn; Vũ khí rơi từ độ cao lớn xuống khu vực sa mạc; Vũ khí được chuyển từ trong nhà ra ngoài trời ở Bắc Cực. Chỉ thực hiện thử nghiệm sốc nhiệt trong không khí và có thể thực hiện thử nghiệm sốc nhiệt từ không khí sang nước trong tương lai. Mục đích của thử nghiệm sốc nhiệt là để kiểm tra tác động của sự thay đổi đột ngột của nhiệt độ môi trường xung quanh đến hiệu suất của vũ khí.

(5) Thử nghiệm bức xạ mặt trời (ánh sáng mặt trời): Đây là thử nghiệm đối với vũ khí và vật liệu chế tạo vũ khí tiếp xúc với ánh sáng mặt trời. Ảnh hưởng của bức xạ mặt trời đối với việc sử dụng hoặc lưu trữ vũ khí hoặc vật liệu liên quan có thể được thử nghiệm thông qua thử nghiệm ánh nắng mặt trời.

(6) Thử mưa: thử nghiệm áp dụng cho các loại vũ khí có thể bị mưa trong quá trình sử dụng. Thử mưa bao gồm thử mưa khi không có gió và thử mưa khi có gió. Mục đích của thử mưa là để kiểm tra hiệu suất chống thấm nước của thiết bị che mưa và hiệu suất của vũ khí trong và sau khi mưa. Độ tin cậy của mạng lưới Trung Quốc

(7) Thử nghiệm chống ẩm: thử nghiệm này áp dụng cho vũ khí có thể sử dụng trong môi trường ấm và ẩm. Các khu vực nhiệt đới có các mùa khác nhau trong cả năm và vĩ độ trung bình, đây là môi trường ấm và ẩm như vậy. Mục đích của thử nghiệm là để kiểm tra khả năng thích ứng của vũ khí với môi trường ấm và ẩm.

(8) Kiểm tra chống nấm mốc: nhiệt độ và độ ẩm là điều kiện cho sự phát triển của vi khuẩn, chúng tồn tại rộng rãi ở vĩ độ nhiệt đới và trung bình. Tất cả các loại vũ khí và thiết bị thông dụng tiêu chuẩn đều phải được thiết kế để chống nấm mốc. Mục đích của thử nghiệm là đánh giá mức độ nấm mốc của vũ khí và tác động của nấm mốc đối với hiệu suất hoặc việc sử dụng vũ khí.

(9) Thử nghiệm phun muối: muối phân bố rộng rãi trên trái đất. Có muối trong đại dương, khí quyển, mặt đất, hồ và sông, đặc biệt là ở các vùng ven biển, nơi có hàm lượng muối tương đối lớn và hàm lượng muối trong đại dương là lớn nhất. Do đó, tất cả các loại vũ khí đều ở trong một số dạng môi trường muối trong vòng đời của chúng. Mục đích của thử nghiệm phun muối là để kiểm tra ảnh hưởng của khí quyển ẩm chứa muối đến hiệu suất của vũ khí, đặc biệt là hiệu suất của lớp phủ bảo vệ và tính tương thích của vật liệu.

(10) Thử nghiệm cát và bụi: thử nghiệm này áp dụng cho tất cả các loại vũ khí cơ học, điện, điện tử và điện hóa được sử dụng trong cát khô hoặc không khí có hàm lượng bụi cao. Thử nghiệm được chia thành thử nghiệm nâng bụi và thử nghiệm nâng cát. Bụi và cát mịn được sử dụng để thử nghiệm nâng bụi. Bụi mịn có thể xâm nhập vào các khe hở, vết nứt, ổ trục và mối nối. 149 ~ 850 được sử dụng để thử nghiệm nâng cát Các hạt cát μ M (micron), các hạt cát lớn và sắc nhọn có thể gây ra xói mòn và tắc nghẽn, đồng thời làm giảm hiệu quả, độ tin cậy và khả năng bảo trì của thiết bị. Mục đích của thử nghiệm cát và bụi là để kiểm tra khả năng sử dụng và lưu trữ của vũ khí trong môi trường cát và bụi.

(11) Thử nghiệm ngâm: thử nghiệm ngâm bao gồm thử nghiệm ngâm, thử nghiệm nhỏ giọt và thử nghiệm nước áp suất. Thử nghiệm ngâm áp dụng cho thiết bị yêu cầu độ kín nước và thiết bị được sử dụng ngâm hoàn toàn hoặc một phần trong nước. Trong một số trường hợp, thử nghiệm này có thể thay thế thử nghiệm mưa để kiểm tra độ kín nước. Mục đích của thử nghiệm là để kiểm tra khả năng ngâm trong nước của vũ khí mà không bị rò rỉ nước.

Cuối cùng nhưng không kém phần quan trọng, GDBELL có 15 năm kinh nghiệm sản xuất và R&D và là nhà sản xuất chuyên nghiệp về buồng thử nghiệm môi trường. Hơn nữa, sản phẩm của chúng tôi có các biện pháp phòng ngừa an toàn chất lượng cao và chưa bao giờ xảy ra tai nạn an toàn trong các thiết bị được bán. Nếu bạn muốn biết về buồng thử nghiệm môi trường, vui lòng liên hệ với chúng tôi!

The temperature test chamber is generally composed of working room, adjusting equipment, auxiliary equipment and control system. The regulating system includes heater, evaporator and air supply device, and auxiliary equipment main room refrigeration unit. The control system includes temperature controller, program setter, safety alarm device and so on.

 

The heater is realized by electric heating of resistance wire or electric heating tube; In addition to the natural heating for the drying oven of high-temperature test without heat dissipation sample, it is generally equipped with air supply device for forced air circulation. The air supply mode is mostly upper side supply and lower side return or full orifice top supply and lower side return, which is very important for the uniformity of the whole test chamber.

 

Most of the refrigeration methods are mechanical refrigeration, the refrigerator has semi closed or fully closed form, and the cooling circuit also has water cooling or air cooling form. Now the refrigerant is mostly environmental friendly, and the throttling method is capillary or electronic expansion valve, which can improve the accuracy and the life of the circuit, and can work continuously for a long time.

 

The control system now generally adopts PID mode, so that the heating power can be automatically adjusted and controlled with the deviation between the actual temperature and the set temperature, realizing stepless adjustment and small temperature fluctuation; The display part has also been upgraded from the previous digital display mode to the LCD touch screen mode, which is clear, beautiful and more convenient for operation. In addition, the insulation layer of the equipment adopts glass wool or polyurethane foam layer, with small thermal conductivity and good temperature resistance. Thermocouple, platinum resistance and thermistor are used for temperature detection with high accuracy.

 

How to choose Temperature Test Chamber？

• It must be required that the test scope should meet the test scope of product failure possibility, that is, the high temperature box or low temperature box or cold and hot impact box should meet the extreme temperature conditions specified in the test requirements.

 

• The selection of test chamber must follow the principle that the sample volume is not more than 1 / 5 of the working volume of the test chamber.

 

• In order to ensure the temperature uniformity of the test area, forced air circulation or non forced air circulation mode is selected according to the heat dissipation of the sample. The difference of equipment temperature distribution has great influence on the test results. When larger samples are used or a large number of samples are tested at the same time, the test results of different positions will be very different. Therefore, the equipment with the best temperature uniformity should be selected.

 

• There are two methods to measure the sample temperature: upwind sensor and downwind sensor. The position and control method of temperature control sensor can be selected, and the appropriate equipment should be selected according to the test requirements.

 

• In order to prevent the sample from absorbing or releasing heat due to heat radiation or heat conduction in the test area, the heating or cooling system of the equipment shall not affect the sample.

 

• It is easy to record and display. Automatic counter, indicator light, recording equipment, automatic shutdown and other instruments should be installed during cycle test.

 

• In order to facilitate the sample placement, the sample holder can be placed or suspended, and the mechanical properties of the sample holder will not change due to the change of high and low temperature.

 

• Leading holes to lead the test power supply to the equipment workshop.

 

• There should be protective measures for the damage of samples and the safety of test personnel. For example, it is equipped with observation window and lighting, and alarm devices such as phase failure, water shortage, over temperature protection and operator protection.

 

• Whether remote monitoring function is needed.

 

 

Precautions when using Temperature Test Chamber

• The temperature and humidity deviation will appear in the updraft and downdraft during the bulk sample test, so the sample location should be carefully considered. It should be placed in the center of the working space of the test chamber as far as possible. The samples should not touch and overlap each other, and a certain interval should be left to make the air circulate; Moreover, it should be ensured that the sample is easy to move during the test, and it is easy to replace the sample during the test.

 

• Check whether there are volatile substances such as oil and gas in the test area and whether there are odorous substances. The test results of such substances must be confirmed in advance.

 

• Pay attention to confirm the temperature condition of the test sample in the test area.

 

• In order to keep the temperature in the temperature zone consistent, it is necessary to ensure the minimum fluctuation of the test environment temperature and the power supply of the equipment as far as possible, so as to ensure that the test sample does not produce heat radiation and does not absorb heat, so as to ensure that the temperature in the test zone is stable.

 

• After the end of the temperature test chamber test, quickly remove the test sample will produce unnecessary stress on the sample, and may get unexpected results. Therefore, the test sample must be cooled to the ambient temperature before it can be taken out.

 

• The thermal conductivity of the installation and support frame of the test sample should be low to ensure that the test sample and the installation and support frame are in an adiabatic state.

 

The test content of different products is decided by the test requester, designer and tester. From the point of view of providing test chamber in accordance with the test, a technical specification framework of test chamber is established, according to which the test chamber supplier can provide the specific specifications of the equipment. Every kind of test chamber that can simulate the test environment generally has a measurement system, so it is very easy to use existing equipment and purchase new equipment. Simple test chamber can also be manufactured by oneself, but the cost, reliability of test results, precise control degree and safety factors of continuous operation should be considered.

 

Conclusion

Environmental test is a process that can add value to products, which can not be ignored. As one of the most basic environmental tests, temperature based environmental test is widely used in many fields, which greatly improves the environmental adaptability and reliability of military and civil products, and directly leads to the improvement of product quality. In this paper, temperature type environmental test chamber are briefly introduced. According to the use requirements, the real purpose of environmental test can be achieved by accurately selecting and using.

As a type of reliability test, environmental test has developed into a method to predict how the product environment affects the performance and function of the product. In other words, environmental tests are used to assess the degree of environmental impact on products before they are put into the market. When the function of the product is affected, the environmental test is used to find out the cause and take measures to protect the product from the environmental impact in order to maintain the reliability of the product. These tests have gone far beyond their original purpose. Now they are widely used in the research and development of materials and products, various inspections in the production process, inspection before transportation and quality control after transportation. They are also used to analyze the defects in the actual use of products and the improvement of new products. Environmental test is very effective for testing methods and maintaining product reliability.

 

The environmental test we are talking about here is in a narrow sense, and actually refers to the artificial simulated environmental test (hereinafter referred to as environmental test). Generally speaking, environmental tests can be divided into three categories: “natural exposure test”, “artificial simulation test” and “field operation test”. The natural exposure test is to test the samples exposed to the natural environment for a long time. Field operation test is to test the sample device in a variety of typical use sites and make it in normal operation state. These two kinds of tests can directly reflect the performance and reliability of products in actual use, and are also the basis of verifying the accuracy of artificial simulation test. However, the test cycle is long, and it costs a lot of manpower and material resources, and the former test conditions can not be controlled, which affects the reproducibility of the test, and sometimes can not keep up with the development of the product; The data feedback of the latter is slow. Therefore, in order to identify the adaptability of products to the environment in a short time, artificial simulated environmental test is often used in scientific research and production, that is, to simulate the role of one or more environmental factors in the laboratory test equipment (chamber or room), and to be appropriately strengthened. The determination of the test conditions of artificial simulation test requires that it can not only simulate the authenticity of the main factors in the environment, but also play a certain accelerating role in time, but the degree of acceleration should not change the law of the actual damage mechanism of the product. Therefore, the test conditions and methods of artificial simulation test must be organically related to the grade and value of product environmental conditions.

 

Of course, the use of environmental testing equipment can not accurately reproduce the product environment and simulate all the environmental factors, so we must understand the limitations of environmental testing. The environmental test composed of a single factor (temperature, humidity, pressure, vibration, shock or a substance such as salt) is called simple environmental test. In fact, it is very difficult to produce a completely single environment, and most of the test environments are very complex. Therefore, when designing test conditions, the testers need to choose the most important environmental factors which have the greatest impact on the products. Therefore, environmental test can only be a human environment which is very different from the real environment. Generally, the defects of the product are caused by the following aspects:

• The concentration and diversity of raw materials, friction, wear, stress, heat, current and electric field strength will affect the performance of some aspects of the product.

• Factors caused by product characteristics (raw materials, manufacturing processes, structural parts and mass production) in the process of product design and manufacturing.

• Stress produced by the external environment.

 

Therefore, the test conditions must be determined according to the specific product conditions, which are different for different products. If the products under test and study have changed, the corresponding environmental tests should also be changed.

 

 

Temperature Stress

Environmental stress conditions can cause product failure. The failure caused by temperature and humidity environmental stress accounts for about 60% of all environmental stress induced failure, and there is a close relationship between temperature stress and failure.

 

At present, all over the world, no matter from land to sea or from high altitude to space, electronic and electrical products and other fields are widely used. Because the temperature decreases with the increase of altitude, or in high latitude areas in winter, or some products are located close to refrigeration elements, equipment or systems, or some products themselves include refrigeration elements, equipment or systems, resulting in low temperature environment. Low temperature will have harmful effects on almost all materials to different degrees. The physical and electrical properties of all kinds of materials that constitute the product will change, which will lead to the temporary or permanent performance decline, even failure.

 

Similarly, the natural high temperature in low latitude tropical areas, the increase of solar radiation, the temperature rise caused by poor ventilation, and the temperature rise caused by the self heating of heat dissipation samples in use will reduce the reliability of electronic combination, and the seals, rubber parts and plastic parts of mechanical structure will rapidly age and deteriorate under high temperature and solar irradiation, The structure, physical properties and electrical properties of other materials will also change greatly, which will lead to temporary or permanent damage and performance changes.

 

In addition, in the process of product storage, transportation, use and installation, in addition to the change of natural climate, we will also encounter the change of environmental temperature caused by human social practice. For example, the equipment moves from the indoor with higher temperature to the outdoor with lower temperature; Or move from the outdoor with relatively low temperature to the indoor with relatively high temperature; Or the equipment used outdoors will suddenly rain or soak in cold water after strong solar radiation; Or the extremely high temperature causes solder reflow, or the temperature of the surrounding devices increases rapidly when the motor is started, and the temperature of the surrounding devices will drop suddenly when the motor is closed; Or the device may be connected to the power supply in a low temperature environment, resulting in a steep temperature gradient inside the device. Cutting off the power supply in a low temperature environment may lead to a steep temperature gradient in the opposite direction inside the device; Or when the aircraft takes off or lands, the temperature of the external equipment on the aircraft may change sharply, etc. Due to the rapid temperature change, the product will be subject to a certain thermal impact force, which will cause the coating layer of electronic and electrical components to fall off, the sealing material to crack or even break, and the filling material to leak, thus causing the electrical performance of electronic components to decline; For the products made of different materials, due to the uneven heating when the temperature changes, the products will be deformed, cracked and broken. Due to the large temperature difference caused by the temperature change, condensation or frosting will occur on the surface of the product at low temperature, and evaporation or melting will occur at high temperature. The repeated action of high and low temperature will lead to and accelerate the corrosion of the product.

 

When the motor is turned off, the temperature of the surrounding devices will drop suddenly; Or the device may be connected to the power supply in a low temperature environment, resulting in a steep temperature gradient inside the device. Cutting off the power supply in a low temperature environment may lead to a steep temperature gradient in the opposite direction inside the device; Or when the aircraft takes off or lands, the temperature of the external equipment on the aircraft may change sharply, etc. Due to the rapid temperature change, the product will be subject to a certain thermal impact force, which will cause the coating layer of electronic and electrical components to fall off, the sealing material to crack or even break, and the filling material to leak, thus causing the electrical performance of electronic components to decline; For the products made of different materials, due to the uneven heating when the temperature changes, the products will be deformed, cracked and broken. Due to the large temperature difference caused by the temperature change, condensation or frosting will occur on the surface of the product at low temperature, and evaporation or melting will occur at high temperature. The repeated action of high and low temperature will lead to and accelerate the corrosion of the product.

Environmental chamber manufacturer DGBELL introduces a great chamber which combines temperature, humidity and vibration into one equipment. This Temperature Humidity Vibration Combined Test Chamber is mainly to simulate the adaptability, safety and integrity of product in the process of transportation and actual use in the change of temperature, humidity, vibration and also other complex environments.

 

Environmental factors should also get analyzed individually when assessing the standard of pieces of apparatus that are vulnerable to vibration and temperature/humidity pressures. The usage Temperature Humidity Vibration Combined Test Chamber simultaneously may end in making top good high excellent products safe from surroundings.

 

Now’s increasingly smaller gadgets and much more diverse. The operation and setup of products are more at risk. Electric apparatus vibration screening has now increased into importance for an outcome. Combined-environment screening unites vibrations using many different environmental pressures like for instance relaxing surroundings, natural surroundings, or high-temperature/humidity atmosphere. It’s a kind of analysis which implements surroundings that closely approximate real working surroundings.

 

Details Information about The Temperature Humidity Vibration Combined Test Chamber

 

Chamber Type

Many are used for aerospace, petroleum electronic industry and communication industry, chemical industry and also other areas.

 

• Vertical type

The chamber size is vary from 408 liters to 1,000 liters and the chamber fixed push the shaker into this area.

 

• Horizontal type

The height of the chamber can be adjusted accordingly. The chamber and the shaker are separate controls. It has one controller for temperature and humidity and another control unit is for vibration systems.

 

 

Chamber Test Capability

If customers have requirements about temperature change rate which like 5°C/min,10°C/min, 15°C/min. This can be an ESS chamber which means you have one temperature humidity, one ESS chamber, one shaker at the same time. It can meet your several test requirements. Like normally temperature and the humidity chamber the temperature range is from -70°C to 150°C. The humidity range is 20% to 98%. The chamber heating rate is 3 to 5 degree per minute and cooling rate is 0.7 degree to 1.5 degree per minute. The temperature uniformity is ±2 degree and humidity of uniformity is ±3%.

 

 

 

Structural Design

The equipment can be divided into six parts. They are test area, vibration, test system, refrigeration system and the circuit system air duct system and control system. Like standard temperature and chamber the inner chamber material is made of SUS#304 stainless steel with 1.2 millimeter thickness, full welding structure link, sealing is very well and not easy to crack.

The external material is made of a cold rolled plate with 1.5 millimeter thickness. It has gone through brushing, polishing, painting treatments so not easy to scratch. The insulation material is made of polyurethane foam and the insulation thickness is 100 millimeter. The door seals adopt double silicone rubber sealing material. The Seal effect is very good. The observation window is four layers of tempered glasses which size you can choose by yourself. In order to prevent glass frosting when running at a low temperature.

 

We set up a heating wire with a safety voltage of 24 volts and set up an LED lamp on the window to provide lighting for observation. The chamber are equipped both sides test cable port of diameter 100mm. The plug material is silicone rubber, high-low temperature resistant and also could preserve heat. The air supply is a two way with air out and air return.

 

 

 

Control System of the Combined Test Chamber

• Vibration Control System

A complete set of vibration test systems is composed of a digital operation controller, power, amplifier, cooling fan and electrodynamic shaker.

In the laboratory with the aid of vibration test system model simulation of reproduction of sinusoidal flow random and resonant search and dwell classic shock and the road simulation can be achieved. It is essential for product quality assurance new product research and development Electromagnetic vibration testing system is specially designed to meet the need of long-term operation, installation of vibration resistance base can be achieved vertical and the horizontal

vibration.

 

The vibration system has the following features: rugged suspension system and linear motion guiding, strong carrying capacity, good guiding function, high stability. Load center airbag has high statics stiffness and low dynamic stiffness, strong carrying capacity, perfect performance on the amplitude vibration. High efficiency D-class power switching, 3 Sigma peak current provide finest power consumption and minimize harmonic reliability.

 

It has a quick safe diagnosis system with safety interlock, high safety reliability. Airbag shock isolation devices for vibration platforms without the need of additional foundation, perfect reproduction of vibrational waves and reduced vibration transmittance. The system also provides horizontal vertical expansion platforms for different applications. It has a simple controller operation. The maximum sine force can be chosen from 30KN to 980KN load. The table size can be chosen from 100 by 106 by 88 millimeters.

 

 

• Temperature and Humidity Control System

We control the temperature and the humidity through the PID module. The controller has a seven inches color touchscreen. Minimum display resolution of this control is temperature 0.01C, humidity is 0.01%. In operation mode you can choose fixing or programming can set program 120 groups. Each group has 99 segments, 999 cycles in total. The controller has several language options.

 

 

• Refrigeration System

Our refrigeration system is a double stage system. Double stage means that we use two compressors in the system. In this chamber we use a compressor from a famous brand. The refrigerant is R404 and R23. This equipment uses thermal expansion valve instead of capillary and cooperates with manual control valve and evaporation pressure protection valve. In this way we cannot only guarantee the cooling rates but also energy saving and also extend the life of the compressor. There is a built-in oil separator from a high-quality brand mainly used to filter impurities in refrigerant. Also, it prevents pipes from being clogged by the impurities.

 

The cooling method of this chamber is air cooling and this is an air-cooled condenser which is customized. There is a filter installed, solenoid valve mainly used to control the flow of refrigerant so that we save energy.

 

 

• Circuit System

Our internal circuit system is very neat and beautiful. Our circuit system wiring according to international standards. The layout and the color of wires complied with international standards and all equipped with line numbers to facilitate maintenance. All parts came from international famous brands.

 

 

• Unique Design

This temperature humidity vibration combined test chamber equipped with the latest electronic lock. The door cannot open as the electronic lock was working which provides double protection for the operator. If you want to open the door you can use the electronic key or enter the password. As we can see the pattern on the control panel is all upgraded to metal type compared with plastic one is more comfortable to use and has a longer service life. The equipment has an indication light on the panel easy to check the chamber running condition.

The chamber also equipped it with an alarm system. Alarm will be running when chamber failure or in operation, the height of the chamber can be adjusted accordingly to you.

 

Conclusion

DGBELL can furnish vibration-test devices together with climatic chambers to present whole shaking, humidity, and temperature ecological screening. Artificial products could be vulnerable to both mechanical and thermal pressures. These approaches may be customized to fulfill their own application. These shouldn’t be regarded as independently, whilst the ramifications could be related.

The cycle life of lithium batteries has always been one of the most important parameters for electric vehicle buyers. How does a lithium battery get old?

Aging always appears together with failure, but to be precise, aging and failure are two concepts. Aging, which refers to the deterioration of power battery performance parameters over time, is a quantitative process, and the parameters mainly refer to the maximum available capacity, internal resistance, and power of the battery. Failure, is the process of the battery completely lost the ability to work, relatively short in time, is a qualitative change. The accumulation of aging is an important cause of failure.

 

Factors affecting aging

The best working temperature of the power battery is 15℃-35℃, but in daily applications, it is impossible to fully meet the needs of the battery, therefore, the most common scenario affecting battery aging is high temperature, low temperature.

 

In addition to the environment, the battery operating parameters will also play a role in accelerating or decelerating the aging, so the choice of cell charging and discharging parameters has a significant impact.

 

Under the action of the external factors listed above, battery electrode materials and other side reactions other than normal charging and discharging occur during the electrochemical reaction, leading to the occurrence of aging.

 

Typical aging process

The specific details of the aging process are closely related to the choice of positive and negative electrode materials, electrolytes, and diaphragm, so this article will explain the aging process in Ontario and will not explain in detail specific materials for the time being.

 

• High-temperature aging

50℃ to 60℃ is the upper limit of the working temperature range that general lithium batteries can allow. When the electrochemical reaction is carried out at a higher temperature, the electrolyte is more active and prone to decomposition reaction, and the decomposition products are combined with the cathode material, which is the consumption of the cathode material; the cathode structure material is corroded, the lattice structure collapses due to the lack of sufficient material support, the empty space for lithium ions is reduced, and the ability of the cathode to accommodate lithium ions decreases, making the battery capacity suffer loss.

 

At the same time, the products reflected by the cathode material, wandering in the electrolyte, may adhere to the surface of the positive and negative electrodes. The electrode surface is covered by substances that cannot participate in the charging and discharging process, which hinders the smooth occurrence of electrochemical processes and increases the internal resistance of the cell.

 

The effect of high temperature process on aging occurs mainly at the positive electrode, and the effect on the negative electrode accounts for a relatively small percentage.

 

• Low temperature aging

When the ambient temperature reaches below 0℃, the performance of Li-ion battery starts to be significantly affected by low temperature.SIE film, a passivation film generated by the reaction between negative electrode material and electrolyte in the process of core formation, has a protective effect on negative electrode material.

 

The thickening of the SEI film makes it more difficult for lithium ions to cross the film layer and reach the cathode, which increases the internal resistance of the cell when combined with the reduced concentration of conductive lithium ions.

 

When charging at low temperature, especially when the charging current is relatively high, another side reaction occurs at the negative electrode – lithium monomer precipitation. At low temperatures, the lithium ion activity decreases and barely charges, causing excess lithium ions to gather around the negative electrode and not be able to cross the SEI film to reach the negative electrode embedding, and then deposit on the negative electrode surface, forming a pure lithium layer. This process tends to occur during charging at too low a temperature and is irreversible. With the accumulation of use cycles, lithium monoliths also continue to accumulate and dendrites continue to grow, making the risk of puncturing the diaphragm cumulative.

 

Lithium batteries work at low temperatures, the aging problem occurs mainly in the negative electrode, the positive side reaction also exists, but the impact is not significant.

 

• High-current charging and discharging

Discharge at a current exceeding the design discharge capacity, on the one hand, the thermal effect of the current, bringing the battery’s own temperature rise, the side effects of high-temperature aging gradually intensified; on the other hand, high current brings an excess of lithium ions to need to be embedded in the cathode material, causing an impact on the stability of the material.

 

High-current discharge, the same problem of heat generation and cathode material de-embedding stability problems. At the same time, too many lithium ions are transported to the negative electrode, exceeding the capacity of the negative electrode, making the deposition of lithium monomers occur. Not only will lose capacity, but the risk of thermal runaway of long-term use also rises, the harm is more serious.

 

• Over-voltage under-voltage charging and discharging

Over-voltage charging and under-voltage discharging will bring about the phase change of the cathode material, which will reduce the empty space to accommodate lithium ions and affect the maximum available capacity of the cell.

 

• Self-discharge

Self-discharge of the battery cell occurs anytime and anywhere, and the self-discharge process is more significant when the temperature is higher and the charge level is higher. The self-discharge process brings about a joint loss of the reversible and irreversible capacity of the battery. The products of self-discharge, attached to the electrode surface, block the lithium-ion channels and reduce the lithium-ion embedding position, which in turn brings permanent capacity loss of the cell.

 

Aging of the module

Li-ion battery is connected in series and parallel to form a module, and the aging of the module is directly affected by the aging of the single cell. In addition, the aging of the cores brings about the deterioration of the consistency between the cores, which makes the aging of the modules amplify on the basis of the aging of the cores.

 

In addition to the influence of core aging, the module will also be affected by vibration and oxidation, and corrosion of conductive parts, which will deepen the aging degree. Between the module internal core and the copper bar, and between the copper bar and the module terminals are kept in close contact by soldering or screw connection to ensure that the resistance is within a reasonable range. The increase of connection resistance brought by vibration and oxidation makes the distribution situation of resistance inside the module change. These changes may affect the detection results of the cell voltage, which in turn affects the charging/discharging and equalization process of the cell.

 

The harsh environment and overloaded working parameters make the aging process more significant and easier to observe by researchers. In fact, the aging process has been going on silently. There are two lifetimes for the cells, the calendar lifetime and the cycle lifetime. From the name of calendar life, we can feel the sleeplessness of aging. Therefore, the research on the factors influencing the aging of electric cores is only trying to reduce the accelerated aging brought by irregular operations.