DL/T 1993-2019Technical specification for recovery, regeneration and reuse of sulphur hexafluoride gas for electrical equipment (English PDF)

4.1 Technical requirements for sulfur hexafluoride gas recovery process

4.1.1 The recovery device shall meet the corresponding requirements of DL/T 662 on the recovery device.

4.1.2 The material, design, manufacturing inspection and acceptance of gas storage vessels shall be carried out in accordance with the requirements of GB 150, and shall comply with Requirements of TSG R0004.The inside of the gas storage container should be clean and free of impurities. The inner wall should be treated with rust prevention, the outer surface paint should be firm and smooth.

4.1.3 During the recovery process, the gas path system should maintain good airtightness to ensure that no gas leakage occurs.

4.1.4 During the recovery process, the gas in the equipment to be recovered should be pumped to an absolute pressure of less than 2kPa.

4.2 Steps for recovery of SF6 gas

4.2.1 Use special pipelines to connect equipment to be recovered, recovery devices and gas storage containers.

4.2.2 Vacuum and self-clean the recovery device, gas storage container and connecting pipeline.

4.2.3 Start the recovery device compressor, open the air release valve of the equipment to be recovered and the air inlet valve of the gas storage container, and start the recovery Close.

4.2.4 After the gas in the equipment to be recovered is evacuated and is less than 133pa, close the inlet valve and return of the gas storage container in turn.

The intake valve of the collection device, the air release valve of the equipment, and the compressor of the recovery device.

4.2.5 Remove the gas storage container and label it for purification. Disconnect the connecting pipe between the equipment to be recovered and the recovery device Road, restore the valve port of the equipment to the closed state.

5.1 Technical requirements for the purification process of sulfur hexafluoride gas

5.1.1 The purification treatment device should meet the requirements of DL/T 1353.Its main function is to detect non-compliant equipment the required sulfur hexafluoride gas is purified.

5.1.2 The pretreatment device is mainly for pretreatment of sulfur hexafluoride gas with high impurity content, and should be able to effectively pass Filter impurities such as moisture, solid particles and decomposition products in the gas.

5.1.3 The material, design, manufacturing inspection and acceptance of gas storage vessels shall be carried out in accordance with the requirements of GB 150, and shall comply with Requirements of TSG R0004.The inside of the gas storage container should be clean and free of impurities. The inner wall should be treated with rust prevention, the outer surface paint should be firm and smooth. The internal cleanliness should be inspected regularly.

5.1.4 Sampling and testing should be carried out before the treatment of sulfur hexafluoride gas. For testing items and methods, refer to DL/T 1366 Required to be carried out, at least including air, moisture, decomposition products (sulfur dioxide, carbon monoxide, hydrogen sulfide).

5.1.5 Sulfur hexafluoride gas with high impurity content (sulfur dioxide greater than 30µL/L) should first be used for pretreatment equipment.

Set up (adsorption filter device) for pretreatment, and then enter the purification treatment system for purification treatment to prevent pollution Purification treatment device.

5.1.6 During the purification process, the gas circuit system should maintain good airtightness to ensure that no gas leakage occurs.

5.1.7 The purified sulfur hexafluoride gas should meet the technical index requirements of fresh gas.

5.1.8 The purification processing speed of sulfur hexafluoride gas should reach 50kg/h, and the processing qualification rate should not be less than 95%.

5.2 Steps of SF6 gas purification treatment

5.2.1 Use special pipelines to connect the gas storage container filled with the gas to be treated and the purification treatment device to ensure the system no leakage.

5.2.2 Fill the sulphur hexafluoride to be treated into the buffer tank to transform it from liquid to gas.

5.2.3 Pass the sulfur hexafluoride into gaseous state through the adsorption tank to remove particles, moisture, decomposition products, and mineral oil Wait.

5.2.4 Adopt solid or liquid separation technology for sulfur hexafluoride gas after adsorption treatment to convert sulfur hexafluoride into it becomes solid or liquid, and the impurity gas is separated.

5.2.5 Slowly warm the treated sulfur hexafluoride to transform the sulfur hexafluoride into liquid or gaseous state.

5.2.6 Use a four-way valve to connect the dedicated pipeline. One end is connected to the vacuum device, which can make the pipeline and the gas storage container the vacuum degree meets the requirements; one end is connected to the purification treatment device, and the pipeline is flushed with the treated sulfur hexafluoride gas;

One end is connected to a vacuumized gas storage container (usually a special steel cylinder), which is used to store the purified six Sulfur fluoride gas; the other end is connected to a gas storage container to store the evacuated gas.

5.2.7 After the treated gas is allowed to stand for 24 hours, it shall be inspected by a qualified unit in accordance with the requirements of DL/T 1366 Perform testing and issue a testing report. Among them, purity, moisture, air, carbon tetrafluoride, hexafluoroethane, eight the fluoropropane indicators should be tested one by one, and the first and last bottles should be checked for other items, and the middle bottle should be in accordance with 6.3.3 of this standard.

Requires random inspection.

6.1 Technical indicators

Regenerative sulfur hexafluoride used in power equipment should meet the requirements of new gas technical indicators. See Table 1 for specific technical indicators.

6.2 Detection method

6.2.1 General provisions

The inspection sample should be liquid sampling, and the sampling shall be carried out in accordance with the provisions of GB/T 6681 and GB/T 3723.Sampling tube the line should be made of stainless steel or Teflon pipe.

Numerical rounding rules and the expression and judgment of limit values shall be implemented in accordance with GB/T 8170.

6.2.2 Detection method

In this standard, sulfur hexafluoride, air, carbon tetrafluoride, hexafluoroethane, octafluoropropane, sulfuryl fluoride, fluorine Reference for testing methods of thionyl, sulfur dioxide, water, acidity, hydrolyzable fluoride, mineral oil and toxicity the provisions of DL/T 1366 shall be implemented.

6.3 Sampling rules

6.3.1 Regenerative sulfur hexafluoride for power equipment shall be processed by the quality supervision and inspection department of the production plant in accordance with the provisions of this standard.

Line inspection. The manufacturer shall ensure that each batch of products manufactured meets the requirements of this standard. Of which moisture, air, the indicators of carbon tetrafluoride, hexafluoroethane and octafluoropropane should be tested one by one, and the first and last bottles should be checked for other items.

The intermediate bottle shall be inspected according to the sampling method required in 6.3.3 of this standard.

6.3.2 The user has the right to inspect the recycled sulphur hexafluoride used for power equipment received in accordance with the provisions of this standard.

Close. Acceptance should be carried out within one month from the date of arrival of the goods.

6.3.3 The bottled recycled sulfur hexafluoride shall be randomly sampled and inspected in accordance with Table 2 and accepted in batches. When any item refers to If the target inspection result does not meet the technical requirements of this part, the random sampling inspection shall be doubled again.

When any index does not meet the technical requirements of this part, the batch of products shall be judged as unqualified.

6.3.4 Large-volume steel seamless gas cylinders containing sulfur hexafluoride (weight >=100kg) products shall be inspected and accepted one by one.

When any of the test results does not meet the technical requirements of this standard, the product is judged as unqualified.

7.1 Technical requirements for the refilling process of regenerated sulfur hexafluoride gas

The recharging device shall meet the corresponding requirements of DL/T 662 on the recharging device. The inlet and outlet pipelines are required to be completed Fully sealed and airtight.

7.2 Steps of refilling regeneration SF6 gas

7.2.1 Before recharging the regenerated sulfur hexafluoride gas, the quality inspection shall be carried out in accordance with the requirements of DL/T 1366, and then confirmed After the raw gas meets the technical index requirements in 6.1, it can be recharged.

7.2.2 Use special pipelines to connect the equipment to be refilled, the refill device and the gas storage container.

7.2.3 Vacuum and self-clean the refill device, gas storage container and connecting pipeline.

7.2.4 Start the compressor of the recharge device, open the inlet valve of the equipment to be recharged and the outlet valve of the gas storage container, and start the recharge Charge.

7.2.5 After the gas pressure in the recharging equipment reaches the rated pressure of the equipment, close the equipment inlet valve and refill in turn.

Device outlet valve, gas storage container outlet valve, refill device compressor.