CO2液体贮槽使用说明书英文版.docx

1、CO2液体贮槽使用说明书英文版Liquid CO2 Storage TankOperation and Maintenance ManualHangZhou Chuankong General Equipment Co.LtdJul. 2007ContentsI. Structure DescriptionII. Operation and Maintenance1. Operation2. MaintenanceIII. Transportation and Installation1. Transportation2. InstallationIV. Safety Requirements

2、 and Precautions1. Safety Requirements2. PrecautionsI. Structure Description1. Main Structure The tank is of double-wall structure. Its inner vessel is made of alloy steel 16MnDR and pipings are made of austenitic stainless steel and its outer vessel is made of carbon steel Q235-B.The jacket between

3、 the two vessels is filled with perlite and evacuated. A specially treated adsorbent is placed in the jacket to prolong the vacuum life of the tank. The tank is equipped with necessary valves around its bottom for operating it.2. Peculiarities(1) Compact structure and less occupied space;(2) The tan

4、k is equipped with the liquid filling connector for filling the liquid to the liquid vaporizers and tankers;(3) The perlite (thermal insulation material) and adsorbent in the jacket have been specially treated so as to prolong the vacuum life. Moreover, the tank is equipped with a metallic thermocou

5、ple gauge tube for measuring the vacuum in the jacket when necessary.II. Operation and Maintenance1. Operation (1) Preparation Before being put into use, the tank must be subjected to a gas-tight test, a purging and a check of valves and instruments. Gas-tight TestThe tank must be subjected to a gas

6、-tight test before the CO2 liquid is filled after the tank is installed or the temperature of the inner vessel returns to the normal temperature. The test pressure should be the MAWP (maximum allowable working pressure) of the tank and the testing gas should be oil-free and dry air or dry nitrogen.

7、The testing time must be four hours or more. Purging After the gas-tight test is accepted, the inner vessel system of the tank must be purged with oil-free and dry air or nitrogen to remove any moisture. After purging with the dry air or nitrogen, the whole system must be further purged with the pro

8、duct gas until the discharged purging gas reaches the required purity. Checking for Valves and Instruments Make sure that all the valves are in correct opening or closing state and that all the instruments are in correct indication, otherwise they must be adjusted properly before the cryogenic liqui

9、d is filled.(2) Liquid Filling The liquid filling is divided into first filling and make-up filling.1 First Filling (i.e. the filling when the inner vessel is at the normal temperature)The filling steps are as per follows:a) Connect the liquid filling pipeline.b) Purge the liquid filling pipeline (t

10、his step must be done before each filling). Before the liquid inlet valve is opened, the liquid transferring pipe must be filled with a small quantity of liquid via the liquid discharging valve and at the same time the residual liquid draining valve must be opened to purge the pipeline for eliminati

11、ng the moist air and mechanical impurities from it.c) Fill gas CO2(pressure1.2MPa,temperature15) from gas-through valve to the inner vessel until the pressure of the inner vessel1.2MPa.d) Open the lower filling valve to fill the liquid from the bottom,the valve must be slightly opened in order to co

12、ol the pipeline and inner vessel gradually to the temperature of the filled liquid. When the liquid level gauge begins indicating liquid level, the filling valve may be further opened to increase the speed of filling.e) When some liquid is sprayed from the fullness test valve which is already opened

13、, it means that the tank has been fully filled with liquid and then the lower filling valve should be immediately closed to stop the filling. At the same time the residual liquid draining valve should be opened to drain off any residual liquid from the liquid filling pipeline. During filling, if nec

14、essary, venting valve can be opened; Pressure of the inner vessel must be higher than 1.2MPa no matter at any condition or at any time.g) Disconnect the liquid filling pipeline upon completion of the liquid filling. Make-up Filling (i.e. the filling when the inner vessel is at the temperature of the

15、 CO2 liquid) The steps for the make-up filling are almost the same as those for the First Filling. The only difference is that some CO2 liquid already exists in the inner vessel and that it is unnecessary to cool the inner vessel. Therefore the liquid may be filled directly from the lower filling va

16、lve after the pipeline is purged.For the relation between the liquid volume and the liquid level, see the curve diagram plate mounted on the tank.(3) StorageDuring storage, pressure change should be logged carefully. When pressure is higher than 2.16MPa, venting valve must be open, but the pressure

17、must be higher than 1.2MPa at any condition.(4) Liquid Discharge There are two types of liquid discharge:1 Discharge of Liquid from outlet valve2 Discharge of Liquid from Liquid Inlet/Outlet Valve The liquid is discharged to a tanker or other bigger tank via the liquid filling hose. Its operating st

18、eps are basically the same as those for the liquid filling, but the lower liquid inlet valve is used for discharging the liquid instead of filling the liquid.2. Maintenance(1) Insulation Performance ProtectionFor the CO2 liquid storing and transporting equipment, the most important requirement is th

19、at they should have good insulation performance and a low boil-off of the cryogenic liquid. Vacuum is the key point of the insulation performance. The thermal conductivity of the perlite at normal temperature and pressure is 0.045 kcal/m.h.K while that at the vacuum of 66.66 1.33 Pa is 0.00225 kcal/

20、m.h.K. So we can see that under the same other conditions the heat transfer difference is 20 times depending on the jacket vacuum (transferred heat: Q = KFt1-1).Whenever the vacuum is deteriorated, it is impossible to store the cryogenic liquid in the tank, so a lot of attentions should be paid to t

21、he vacuum of the tank. The outer vessel anti-explosion device and theevacuating valve are directly communicated with the vacuum jacket. It is not allowed to dismantle them if the vacuum is not deteriorated or it is unnecessary to make up the perlite and to re-evacuate the jacket. The evacuating valv

22、e is lead-sealed and it is prohibited to remove the valve at random.The outer vessel is an external pressure vessel and subjected to the atmospheric pressure and thus no striking or bumping is allowed to avoid any damage to the outer vessel. It is not allowed to place the tank in the area where the

23、temperature is higher than 50C, otherwise the vacuum will be affected and the insulation performance will be lowered.(2) Vacuum Examination and Re-evacuation Vacuum of the tank shall be checked every half a year in general. When measuring the vacuum, remove the cover of the metallic thermocouple tub

24、e and insert the plug of the thermocouple vacuum gauge, thus the vacuum level in the jacket can be measured. For details, refer to the operation manual of the thermocouple vacuum gauge.After several years operation, the vacuum may drop to the value lower than 67 Pa and it is necessary to re-evacuate

25、 the jacket to improve the insulation performance. Before re-evacuation, the liquid in the tank must be discharged entirely and then the tank must be warmed and purged with dry and oil-free air or the gaseous nitrogen at 80100C until it recovers to the normal temperature. Upon completion of connecti

26、ng the evacuating piping, the pump must be firstly started for pumping out the moisture in the air of the vacuum pipe and then the vacuum valve may be opened for re-evacuating.For the details of evacuation, if necessary, the user can contact with the tank manufacturer. Both parties can decide throug

27、h discussion the specific procedure of evacuation.(3) Checking and Troubleshooting1 Normal Checkinga) Make sure that the valves are in proper opening/closing position;b) Make sure that the pressure gauges and liquid level gauge is correct and reliable;c) Make sure that there is no leakage or blockag

28、e in the pipeline andvalves;d) When the pressure in the tank gets to the opening pressure of the safety valve but the valve does not work, the opening pressure of the valve must be calibrated immediately to insure the safety of the tank.2 Periodical Checkinga) The pressure gauges shall be calibrated

29、 once half a year;b) The safety valve shall be calibrated once a year;c) The vacuum in the jacket shall be measured every half a year; Trouble-shooting For the details of troubles that may possibly occur during operation and their cause and remedy, see Table 1.Table 1. TroubleshootingTroubleCauseRem

30、edyInternal pressure rises abnormally during operation.a. Pressure gauge indicates incorrectly.Repair or replace the pressure gauge.b. Vacuum of interlayer deterioratedRe-evacuateLiquid levelgauge indicates incorrectlya) The gauge is out of order.Repair the liquid level gauge.b) Upper and lower pipe

31、s of the gauge leak.Check them and eliminate the leakage.c) The joint of the gauge leaks.Check it and eliminate the leakage.The boil-off is too high and some frost occurs at the top of the tank.a) The vacuum is deteriorated.Re-evacuate the jacket.b) The perlite sinks and is not filled densely.Add pe

32、rlite and re-evacuate the jacket.Some liquid or gas leaks from the valve cap or joint.a) Sealing packing is not pressed tightly.Tighten the packing gland.b) Sealing ring is broken.Replace the sealing ring.c) Sealing face is damaged.Replace or replace the part.d) Some weld leaks.Repair the weld as per the specific procedure.III. Transportation and Installation3. Transportation(1) After the tank arrives at the