Background technology
Ethene is one of the most important basic material of petrochemical industry. From the fifties in last century, the country of some petrochemical industry advanced technology develops hydrocarbon cracking technology in succession, and this facilitates the development of synthetic material industry greatly. At present, the general plastics such as polyethylene that hydrocarbons produces, polypropylene, vinylbenzene are utilized to spread all over the every nook and cranny of daily life. Along with the sustainable development of China's Petrochemical and national economy, the demand of ethene being continued to increase, domestic ethylene turnout can not satisfy the demands, thus needs a large amount of import.
The import of ethene adopts the mode of atmospheric low-temperature groove ship usually, liquid ethylene shipping is come back home. The volume of-104 DEG C of liquid ethylenes of the inferior weight of normal pressure is about under normal pressure the 1/490 of gaseous ethylene, the much smaller of the gaseous ethylene of the volume ratio equivalent weight of liquid ethylene under visible equipressure, thus accumulating liquid ethylene also just has more advantages than accumulating gaseous ethylene. After liquid ethylene shipping is come back home, need to be stored in liquid ethylene storage tank, when the demand obtaining downstream user indicates, by be arranged on that storage tank is outer and the liquid ethylene transferpump that is connected with storage tank to the liquid ethylene positive delivery in storage tank to gasifier, through the gasification of gasifier, the gaseous ethylene obtaining high pressure is carried and is used to downstream user.
The liquid ethylene temperature of low temperature very low (about-104 DEG C), the very big temperature difference (about 130 DEG C) is there is with envrionment temperature, therefore unloading a ship, pump pressurizes, Cemented filling, storage tank is deposited etc. in technological process, the heat of absorbing environmental can produce a large amount of boil-off gas (BOG, BoilOffGas), the composition of BOG is still ethene, if do not recycled, directly discharge, cause waste on the one hand, also the problem of environmental pollution can be brought in addition, especially at present day by day serious haze weather, ethene discharge needs strict limitation, therefore the key that BOG is the process system design of ethene receiving station how is rationally reclaimed.
Summary of the invention
The present invention provides a kind of energy-saving low-temperature ethylene gas metallization processes system adopting the condenser of economizer/again, in order to overcome at least one problem that prior art exists.
For achieving the above object, the present invention provides a kind of energy-saving low-temperature ethylene gas metallization processes system adopting economizer, comprise: low temperature liquid ethene is unloaded a ship arm, pipeline of unloading a ship, low temperature liquid ethene storage tank, BOG compressor unit, economizer, ethene vaporizer, low temperature ethylene pump and ethene topping-up pump, wherein:
Described pipeline of unloading a ship is connected to described low temperature liquid ethene and unloads a ship between one end of arm and described low temperature ethylene storage tank, the unload a ship the other end of arm of described low temperature liquid ethene is connected with ethene transport-ship, by the pressurization of the topping-up pump that is arranged on Liquefied Ethylene Carriers, by the low temperature liquid ethene on Liquefied Ethylene Carriers by described low temperature liquid ethene unload a ship arm, described in pipeline of unloading a ship be transported in described low temperature liquid ethene storage tank;
Described low temperature ethylene pump is arranged in described low temperature liquid ethene storage tank, and described economizer is connected with described low temperature liquid ethene storage tank, and described low temperature ethylene pump is by the extremely described economizer of the low temperature ethylene positive delivery in described low temperature liquid ethene storage tank;
Between the top that described BOG compressor unit is connected to described low temperature liquid ethene storage tank and described economizer, BOG in described low temperature liquid ethene storage tank is condensed into ethene after described BOG compressor unit is compressed in described economizer, and the ethene that this strand is condensed into converges with the liquid ethylene from described low temperature liquid ethene storage tank in the outlet of described economizer;
Described ethene topping-up pump is connected between described ethene vaporizer and the outlet of described economizer, liquid ethylene after converging is pressurized to the pressure of downstream user needs through described ethene topping-up pump, then through the gasification of described ethene vaporizer, and used to downstream user by the Cemented filling being connected with described ethene vaporizer.
Further, described BOG compressor unit can comprise multi-stage compressor, and when the temperature of pressurized gas exceedes set temperature value, is also provided with interstage cooler between each stage compressor.
For achieving the above object, present invention also offers a kind of energy-saving low-temperature ethylene gas metallization processes system adopting again condenser, comprise: low temperature liquid ethene is unloaded a ship arm, pipeline of unloading a ship, low temperature liquid ethene storage tank, BOG compressor unit, again condenser, ethene vaporizer, low temperature ethylene pump and ethene topping-up pump, wherein:
Described pipeline of unloading a ship is connected to described low temperature liquid ethene and unloads a ship between one end of arm and described low temperature ethylene storage tank, the unload a ship the other end of arm of described low temperature liquid ethene is connected with ethene transport-ship, by the pressurization of the topping-up pump that is arranged on Liquefied Ethylene Carriers, by the low temperature liquid ethene on Liquefied Ethylene Carriers by described low temperature liquid ethene unload a ship arm, described in pipeline of unloading a ship be transported in described low temperature liquid ethene storage tank;
Described low temperature ethylene pump is arranged in described low temperature liquid ethene storage tank, and described condenser again is connected with described low temperature liquid ethene storage tank, and described low temperature ethylene pump is by the extremely described condenser again of the low temperature ethylene positive delivery in described low temperature liquid ethene storage tank;
Described BOG compressor unit is connected to the top of described low temperature liquid ethene storage tank and described again between condenser, and the BOG in described low temperature liquid ethene storage tank mixes with the liquid ethylene from described low temperature liquid ethene storage tank in described condenser again after described BOG compressor unit is compressed and is condensed into liquid ethylene;
Described ethene topping-up pump is connected between the outlet of described ethene vaporizer and described condenser again, liquid ethylene after converging is pressurized to the pressure of downstream user needs through described ethene topping-up pump, then through the gasification of described ethene vaporizer, and used to downstream user by the Cemented filling being connected with described ethene vaporizer.
Further, described BOG compressor unit can comprise multi-stage compressor, and when the temperature of pressurized gas exceedes set temperature value, is also provided with interstage cooler between each stage compressor.
The present invention is by adopting economizer or condenser again, utilize the cold of the liquid ethylene in storage tank that BOG has been condensed into liquid phase, and supercharging gasification is outer defeated together with after liquid ethylene mixing, calculates after deliberation and show, can obviously reduce power consumption and the cost of gasification output system.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, it is clear that described embodiment is only the present invention's part embodiment, instead of whole embodiments. Based on the embodiment in the present invention, those of ordinary skill in the art, not paying other embodiments all obtained under creative work prerequisite, belong to the scope of protection of the invention.
Following examples have two kinds of technical process forms, all can reach identical technique effect. The nucleus equipment of these two kinds of technical process is economizer and condenser more respectively, therefore can be referred to as the outer defeated method of economizer and condenser defeated method outward again.
Fig. 1 embodiment is the outer defeated method of economizer, as shown in Figure 1, this energy-saving low-temperature liquid ethylene gasifying process system comprises: low temperature liquid ethene is unloaded a ship arm, pipeline of unloading a ship, low temperature liquid ethene storage tank, BOG compressor unit, economizer, ethene vaporizer, low temperature ethylene pump and ethene topping-up pump, wherein:
Pipeline of unloading a ship is connected to low temperature liquid ethene and unloads a ship between one end of arm and low temperature ethylene storage tank, the unload a ship the other end of arm of low temperature liquid ethene is connected with ethene transport-ship, by the pressurization of the topping-up pump that is arranged on Liquefied Ethylene Carriers, the low temperature liquid ethene on Liquefied Ethylene Carriers is transported in low temperature liquid ethene storage tank by unload a ship arm, pipeline of unloading a ship of low temperature liquid ethene;
Low temperature ethylene pump is arranged in low temperature liquid ethene storage tank, and economizer is connected with low temperature liquid ethene storage tank, low temperature ethylene pump by the low temperature liquid ethene positive delivery in low temperature liquid ethene storage tank to economizer;
Between the top that BOG compressor unit is connected to low temperature liquid ethene storage tank and economizer, BOG in low temperature liquid ethene storage tank is condensed into ethene after BOG compressor unit is compressed in economizer, and the ethene that this strand is condensed into converges with the liquid ethylene from low temperature liquid ethene storage tank in the outlet of economizer;
Ethene topping-up pump is connected between ethene vaporizer and the outlet of economizer, liquid ethylene after converging is pressurized to the pressure of downstream user needs through ethene topping-up pump, then through the gasification of ethene vaporizer, and used to downstream user by the Cemented filling being connected with ethene vaporizer.
Further, BOG compressor unit can comprise multi-stage compressor, and when the temperature of pressurized gas exceedes set temperature value, is also provided with interstage cooler between each stage compressor. As in one embodiment of the invention, BOG compressor unit comprises the first step compressor, compressor inter-stage cooler and second and third stage compressor that are connected successively.
In the outer defeated method of economizer, low temperature liquid ethene arm of unloading a ship ships with Liquefied Ethylene Carriers and connects, pressurizeed by the pump on ship, by the low temperature liquid ethene on ship by arm of unloading a ship, pipeline of unloading a ship is transported in low temperature liquid ethene storage tank, low temperature ethylene pump is arranged in storage tank, pump by the low temperature ethylene positive delivery in storage tank to economizer, economizer carries out heat exchange with the BOG after BOG compressor compresses, and BOG is condensed into liquid ethylene, this strand of liquid ethylene is sent to economizer outlet, after converging with the liquid ethylene from storage tank, enter the pressure that ethene topping-up pump is pressurized to downstream user and needs together, then ethene gasifier gasification is entered outer defeated, downstream user is sent to use by pipeline.
Fig. 2 embodiment is the outer defeated method of economizer, as shown in Figure 2, this energy-saving low-temperature liquid ethylene gasifying process system comprises: low temperature liquid ethene is unloaded a ship arm, pipeline of unloading a ship, low temperature liquid ethene storage tank, BOG compressor unit, again condenser, ethene vaporizer, low temperature ethylene pump and ethene topping-up pump, wherein:
Pipeline of unloading a ship is connected to low temperature liquid ethene and unloads a ship between one end of arm and low temperature ethylene storage tank, the unload a ship the other end of arm of low temperature liquid ethene is connected with ethene transport-ship, by the pressurization of the topping-up pump that is arranged on Liquefied Ethylene Carriers, the low temperature liquid ethene on Liquefied Ethylene Carriers is transported in low temperature liquid ethene storage tank by unload a ship arm, pipeline of unloading a ship of low temperature liquid ethene;
Low temperature ethylene pump is arranged in low temperature liquid ethene storage tank, then condenser is connected with low temperature liquid ethene storage tank, and low temperature ethylene pump is by the condenser extremely again of the low temperature ethylene positive delivery in low temperature liquid ethene storage tank;
BOG compressor unit is connected to the top of low temperature liquid ethene storage tank and again between condenser, the BOG in low temperature liquid ethene storage tank mixes with the liquid ethylene from low temperature liquid ethene storage tank in condenser again after BOG compressor unit is compressed and is condensed into liquid ethylene;
Ethene topping-up pump is connected between ethene vaporizer and the outlet of condenser again, liquid ethylene after converging is pressurized to the pressure of downstream user needs through ethene topping-up pump, then through the gasification of ethene vaporizer, and used to downstream user by the Cemented filling being connected with ethene vaporizer.
Further, BOG compressor unit can comprise multi-stage compressor, and when the temperature of pressurized gas exceedes set temperature value, is also provided with interstage cooler between each stage compressor. As in one embodiment of the invention, BOG compressor unit comprises the first step compressor, compressor inter-stage cooler and second and third stage compressor that are connected successively.
In the outer defeated method of condenser again, condenser instead of economizer again, BOG can follow the liquid ethylene direct contact heat transfer in condenser again from storage tank, formed after mixing carry out after one new liquid ethylene meets the requirements of pressure, temperature by topping-up pump and ethene vaporizer outer defeated. The technical process of two kinds of methods is slightly different, but according to result of study, its system power dissipation is identical.
With ethylene gas outer defeated pressure 50barg, ethene work output 25t/h, output temperature 20 DEG C, the outer defeated method of economizer is adopted to be example. Under this condition, BOG compressor delivery pressure and low temperature ethylene pump outlet pressure are all 7barg, and economizer also completes the heat exchange of BOG and low temperature liquid ethene at this pressure. Calculating according to research, BOG compressor unit power consumption is 187kW, the power consumption of two ethene pumps and be 91kW, total power consumption of whole system be both sum, i.e. 278kW. Under same initial conditions, directly the BOG compressor delivery pressure needs in the outer defeated method of compression are brought up to identical with outer defeated pressure, i.e. 50barg. According to calculation result, now BOG compressor unit power consumption is 446kW, the compressor power consumption being much higher than in the outer defeated method of economizer. The key parameter synopsis of three kinds of BOG treatment processs when table 1 is outer defeated pressure 50barg, as shown in Table 1, the outer defeated method of economizer defeated method outer than directly compression saves total power consumption of nearly 50%.
Table 1
In the outer defeated method of economizer, add an economizer and an ethene Send out pump. Assume newly added equipment cost by 2,000,000 yuan, factory working time in year by 8000 hours, the electricity charge by 0.6 yuan/degree, according to calculating, 1.7 years i.e. recoverable cost, therefore the outer defeated feasible process of economizer. And under the outer defeated pressure of height, directly the BOG compressor in the outer defeated method of compression also needs to increase the progression of compressor, causes BOG compressor apparatus cost value to increase.
Consistent in the outer defeated method principle of the outer defeated law and economy device of condenser again, it is all that BOG has been condensed into liquid phase by the cold of the liquid ethylene that make use of in storage tank, and supercharging gasification is outer defeated together with after liquid ethylene mixing. This flow process power consumption is found in table 1, and its numerical value defeated method outer with economizer is identical. Therefore two methods can be equal to a kind of technology, but different technical process can be selected according to different demands in practical engineering project.
One of ordinary skill in the art will appreciate that: accompanying drawing is the schematic diagram of an embodiment, module or flow process in accompanying drawing might not be that enforcement the present invention is necessary.
One of ordinary skill in the art will appreciate that: the module in device in embodiment can describe according to embodiment and be distributed in the device of embodiment, it is also possible to carries out respective change and is arranged in the one or more devices being different from the present embodiment. The module of above-described embodiment can merge into a module, it is also possible to splits into multiple submodule block further.
Last it is noted that above embodiment is only in order to illustrate the technical scheme of the present invention, it is not intended to limit; Although with reference to previous embodiment to invention has been detailed description, it will be understood by those within the art that: the technical scheme described in previous embodiment still can be modified by it, or wherein part technology feature is carried out equivalent replacement; And these amendments or replacement, do not make the spirit and scope of the essence disengaging embodiment of the present invention technical scheme of appropriate technical solution.