1、 Equipment name and model:

The Hot vacuum test chamber, also known as the hot vacuum test box, is used to conduct thermal cycling tests on specimens under vacuum conditions.

The hot vacuum test chamber includes the following components:

-Vacuum container, vertical box, hinged door.

-Vacuum box size: 400 mmX 400mmX200mm (width * depth * height), quantity is 3.

-Dimensions: Approximately 1500mm x 1500mm x 1800mm (width x depth x height)

2. Box body

The shell of the hot vacuum system can withstand external pressure (vacuum). The shell in contact with High vacuum inside the test chamber is made of 304L stainless steel, with a thickness that ensures structural and dimensional stability.

-All inner surfaces have been treated with material venting and sealed internally. All hardware inside the test chamber is made of stainless steel or high vacuum materials.

3. Vacuum system

Control principle: The pressure transmitter detects the pressure inside the working chamber and compares the detected pressure signal with the set value of the control instrument after amplification, analog-to-digital conversion, and nonlinear compensation. The deviation signal generated from this is used to control the opening and closing of the solenoid valve, keeping the pressure in the working chamber within a certain range.

Pressure sensor armored pressure transmitter

1 set of vacuum pump; When the pressure drops from atmospheric pressure to 10Pa, the mechanical pump starts to rapidly reduce the pressure. It will take approximately 1 hour

When the pressure drops from 10 Pa to 10-5 Pa, the molecular pump begins to decrease in pressure. It will take about 3 hours

The vacuum unit can simultaneously connect three experimental chambers and evacuate them. If you want to vacuum each experiment separately, just open the valve. In order to better meet the requirements of independent vacuum pumping, we have equipped three molecular pumps connected to three chambers, achieving fast, stable, and high-precision results.

4. The control method adopts dynamic pressure balance, which is implemented under continuous operation of the vacuum system

The dynamic balance is now controlled, and the control system automatically controls the operation of the vacuum solenoid valve and vacuum pump (including frequency converter) based on the pressure setting value, adjusting the amount of suction/intake to achieve the requirements of dynamic pressure balance. The control effect is shown in the following figure:

The vacuum system has the following functions (to maintain cleanliness inside the box and without test specimens):

Pressure range: 1 atmosphere~5 * 10-5 Pa

Ultimate pressure: ≤ 5.0X10-5pa (under no-load and normal temperature conditions), arrive within 3 hours after operation.

Test pressure:

≤ 1.0 × 10-4-pa (with load, under the condition of box temperature of 80 ℃);

Vacuum extraction time (from 1 atmosphere to 5X10-4 Pa): approximately 4 hours.

Vacuum acquisition time: ≤ 1.0 × 10-3-pa within 1 hour after operation (with load), ≤ 1.0 × 10-4-pa after 2 hours. Start extracting vacuum from atmospheric pressure.

5. The vacuum system includes a main pump (mechanical pump) system, consisting of three sets of molecular pumps and one set of mechanical pumps; After setting the vacuum degree of the equipment, it can control automatic vacuuming.

It also includes a set of connecting pipes for vacuuming and vacuum control; There are also valves, accessories, vacuum sensors, and interlocking devices that can ensure normal operation, monitoring, and safety.

The main pump system consists of the following parts:

Vacuum pump, model: 620C

L P vacuum pumping rate: 300L/S

Ultimate voltage division:& lt;6*10-1 Pa .

Mechanical pump RT-250, equipped with frequency converter

Vacuum pump unit

Vacuum sensor

Pirani and MKS 974 vacuum sensors installed on the system will be tested.

The installation interface will include two vacuum gauges (model: ZJ-27) and two ionization vacuum gauges (model: ZDR-27B) for measuring high vacuum pressure (less than 10-3 Pa)

Note: In order to achieve safe operation, the entire vacuum system will be equipped with interlocking devices.

Re pressure system of hot vacuum test chamber

Thermal cycle system

A non sealed circulation system can eliminate all leakage risks caused by seal wear. In addition, this configuration reduces heat transfer from the motor to the fluid.

The electric heat exchanger consists of multiple isolated heaters and is PID controlled by an independent over temperature safety switch.

Thermal cycle system performance

The performance of the thermal cycling system is as follows:

Equipment temperature range RT+15 ℃ -150 ℃

Equipment control accuracy ≤± 2 ℃

Temperature deviation ≤± 2 ℃ (calibration according to JJF1101-2003)

Uniformity

≤ 2 ℃ (calibration according to JJF1101-2003)

Volatility ≤ ± 1 ℃ (calibration based on JJF1101-2003)

The equipment layout control box and test box are integrated, and the testing space is located above the equipment, divided into three experimental chambers and one storage cabinet.

Sealing strip: Silicone sealing strip

The test box door is installed in front of the test box, and an observation window is set on the door

Set up power cable holes and main power switch behind the equipment

Install mobile casters and positioning foot cups at the bottom of the box

The oil return system is equipped with a 1101A condensing device at the end of the corrugated pipe. When oily substances pass through the pipe, the electric heating bag will heat them up, causing the oil to quickly evaporate and trigger the condenser to turn into liquid oil and be discharged. Will not enter the experimental chamber.

The filter device has 180 pleated layers on both sides of the filter material. The high-temperature resistant and efficient filter is made of ultra-fine glass fiber filter paper, aluminum foil partition plate, galvanized frame or stainless steel frame, and sealed with imported high-temperature resistant sealant Low resistance, high efficiency, good high temperature resistance, can work normally at 200 ℃, effectively preventing air suspended particles above 0.5um from entering the cavity. Depending on the frequency of use, replacing the filtering device takes 1-3 years

The inner box is made of SUS304 # stainless steel plate, which is cut using precision laser cutting equipment and bent into shape using a CNC bending machine. It is then fully welded using argon arc welding, polished and finished; The steel plate is 2mm thick

The insulation material is made of polyurethane rigid foam and glass fiber cotton, with a thickness of 100mm. It has better insulation performance than ordinary insulation cotton, saving electricity and reducing the impact on the ambient temperature of the equipment

Box door single door, explosion-proof handle

Anti condensation electric heating device

Vacuum automatic defogging transparent window, window lighting

Insulation layer rigid polyurethane foam+glass fiber

Observation window transparent electric heating film insulated tempered glass (located on the door) (with anti condensation function), size 200X150mm

Each experimental chamber has an observation window

Distribution control cabinet main power circuit breaker, controller, distribution board, cooling fan, over temperature protector

a distribution board

The heating system adopts a scale heat dissipation heating tube P I. D controls heating to achieve temperature equilibrium

The heater is made of exposed spiral nickel chromium heating wire and insulated ceramic bracket, with low surface load, sensitive temperature control, and small temperature hysteresis.

Heater control mode: PID+PWM+ SSR， Solid state relays are used for contactless zero crossing triggering to drive heaters, with no contact sparks or noise, and a long service life.

Controller, capable of separately controlling parameters such as temperature, vacuum degree, and time for three vacuum boxes

LCD display touch screen

Program capacity and available program quantity for control functions: up to 120 groups, one program can be combined from 1 to 99 segments

Usable memory capacity: 1200 segments, can execute commands repeatedly: each command can be executed up to 999 times, program slope can be set by the timeline, programs can be linked and used, and program creation adopts conversational operation with simple operation

Equipped with functions such as editing, clearing, and inserting, with 4 sets of time signal output control (controllable control of the ON/OFF action of the test object)

It has 9 sets of PID parameter settings, with jump and hold functions during program execution, and can display curves and obtain data; Date and time adjustment function; Button and screen lock (LOCK) function, can be connected to a computer for use

RS-485 communication interface can be used as a monitoring and remote control system to record test data

Running mode, program mode/fixed value mode

Setting method: Chinese interface, touch input

Set the maximum temperature range with upper and lower limits of 5 ℃

Display resolution temperature: 0.01 ℃; Humidity: 0.1%; Time: 1min;

Protection function: independent studio, over temperature protection, vacuum pump overload protection, leakage protection, power supply phase loss and phase sequence error protection, test box shell grounding protection, over temperature alarm, over temperature automatic power-off function, etc

The power-off memory function can set the power-off recovery mode to: hot start/cold start/stop

Input PT100 platinum resistor

The curve recording function has RAM with battery protection, which can save the set values, sampling values, and sampling time of the device; The maximum recording time is 60 days (when the sampling period is 1.5 minutes)

Software usage environment: IBM PC compatible machine, CPU with P Ⅱ or above, 128MB or above memory, Simplified Chinese Windows 2000 or Simplified Chinese Windows XP operating system

Imported nickel chromium alloy electric heater

Heater control method: contactless equal period pulse width modulation, SSR (solid-state relay)

Control method: anti integral saturation PID, BTC balance temperature control method (temperature testing equipment)

BTHC Balanced Temperature and Humidity Control Method (Temperature and Humidity Testing Equipment)

Set range temperature: Adjust according to the temperature working range of the device (upper limit+5 ℃, lower limit -5 ℃)

Input platinum resistor

Supplementary functions

(Standard configuration) Fault alarm and cause, processing prompt function

A fail-safe mechanism

Upper and lower temperature protection function