Normal-temperature storage and low-temperature C1-C4 liquefied hydrocarbon gasification system and method

Abstract

The invention relates to the technical field of low-temperature liquefied hydrocarbon gasification, in particular to a system and method for normal-temperature storage and low-temperature C1-C4 liquefied hydrocarbon gasification. The system comprises a low-temperature liquefied hydrocarbon storage raw material tank, a low-temperature liquid booster pump, a liquefied hydrocarbon gasifier, a circulating air heater and a circulating fan which are sequentially connected through pipelines and necessary pipe fittings, and the circulating fan is connected with the liquefied hydrocarbon gasifier to form a low-temperature liquefied hydrocarbon gasification flow path and a circulating gas flow path. The low-temperature liquefied hydrocarbon gasification flow path is a flow path for heating and gasifying liquid hydrocarbon by the liquefied hydrocarbon gasifier to form gas hydrocarbon to an external production device; and the circulating gas flow path is a flow path through which circulating gas circulates between the liquefied hydrocarbon gasifier and the circulating air heater under the pressurization of the circulating fan. The system is safe, reliable, feasible in industrialization and stable in operation, the frosting problem of the air temperature type vaporizer can be effectively solved, the process is simple, and a heating medium is safe, environmentally friendly and easy to obtain.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gasification of low-temperature liquefied hydrocarbon gas, and in particular to a system and method for gasification of low-temperature C1-C4 liquefied hydrocarbon gas stored at room temperature. BACKGROUND

[0002] With the rapid expansion and development of C1-C4 liquefied hydrocarbon downstream industries, the market demand for C1-C4 liquefied hydrocarbon is continuously rising. Under this background, the diversification of C1-C4 liquefied hydrocarbon supply has become one of the key elements affecting the stable production of factories. From the perspective of trade transportation, long-distance transportation of C1-C4 liquefied hydrocarbon currently generally adopts the transportation mode of "atmospheric low-temperature liquid tank truck"; but from the terminal demand side, most C1-C4 liquefied hydrocarbon downstream enterprises actually need "high-pressure gas-phase hydrocarbon", which requires the liquid liquefied hydrocarbon to complete the transformation of form and pressure after delivery. The specific operation process is as follows: after the liquid liquefied hydrocarbon is unloaded by the tank truck, it is first stored in a low-temperature liquefied hydrocarbon storage tank; then, it is pressurized by a liquid-phase submersible pump, and the pressurized liquefied hydrocarbon is transported to a gasifier; finally, the high-pressure gas-phase hydrocarbon is generated after the gasification in the gasifier. In the process of converting liquefied hydrocarbon into downstream products, gas is used as the core raw material, which is first converted into intermediate products through a key addition or combination reaction with specific reactants in the presence of a catalyst, and then through subsequent steps such as dehydrogenation and direct conversion, finally generating target downstream chemical products.

[0003] In the domestic industrial scene, the commonly used types of gasifiers include air temperature type, electric heating type, water bath type and hot water circulation type. Among them, the air temperature type gasifier is the most widely used in various scenes due to its outstanding advantages of green environmental protection and high efficiency and energy saving. However, the running effect of the air temperature type gasifier is greatly affected by the outside environment temperature, and frost is easily formed on the outside of the finned tube when the air temperature is low, which will seriously hinder the heat exchange efficiency and greatly weaken the gasification effect. At the same time, the existing other heating processes in the industry not only have complex operation processes, but also use dangerous chemicals such as propane as the heat medium, which has obvious safety risks in storage, transportation and use, and is not conducive to production safety control.

[0004] At present, the reported methods for liquefied hydrocarbon warming and gasification are summarized as follows: The invention patent with publication number CN 120140643 A discloses a system for liquefied low-temperature ethylene warming and pressurization, in which liquid ethylene is sent to an ethylene gasifier by a submersible pump, and propane is used as a heat medium to gasify the ethylene. Since propane is a dangerous chemical, there is a safety risk in use, which is not conducive to production safety control.

[0005] The invention patent with publication number CN 109058758 A discloses an ethylene comprehensive conveying system and method. The ethylene heater and the ethylene vaporizer both adopt a cascade heat exchange structure. Methanol is filled in the shell as an intermediate heat transfer medium. The upper heat absorption coil is passed through ethylene, and the lower heat release coil is passed through steam (or other heating medium), forming a heat exchange path of "steam heating methanol, and methanol heating ethylene". Methanol is flammable and toxic. Its vapor can easily form an explosive mixture with air, and human contact or inhalation can cause poisoning. The cascade heat exchange scheme has the disadvantages of additional handling of methanol storage, transportation and leakage risk, increased equipment investment and operation and maintenance cost, and certain volatility of methanol itself, which may cause medium loss and potential safety hazards. SUMMARY

[0006] The application provides a system and method for gasification of low-temperature C1-C4 liquefied hydrocarbon stored at room temperature. The system provided by the application is safe and reliable, industrially feasible and stable in operation, can effectively solve the frosting problem of air temperature type gasifiers, and has a simple process, safe and environmentally friendly heat medium and easy availability.

[0007] In a first aspect, a system for gasification of low-temperature C1-C4 liquefied hydrocarbon stored at room temperature is provided, which adopts the following technical scheme: A system for gasification of low-temperature C1-C4 liquefied hydrocarbon stored at room temperature, the system comprising a low-temperature storage liquefied hydrocarbon raw material tank, a low-temperature liquid booster pump, a liquefied hydrocarbon gasifier, a circulating air heater and a circulating air fan connected in sequence through pipelines and necessary pipe fittings, wherein the circulating air fan is connected to the liquefied hydrocarbon gasifier. The liquefied hydrocarbon gasifier is connected to a production device. Liquefied hydrocarbon is introduced into the low-temperature storage liquefied hydrocarbon raw material tank from the outside, enters the liquefied hydrocarbon gasifier under the action of the low-temperature liquid booster pump, is gasified after transportation to the production device for use, and forms a low-temperature liquefied hydrocarbon gasification flow path. The energy required for gasification is provided by the circulating gas heated by the circulating air heater. A circulating gas supplement pipeline is provided between the liquefied hydrocarbon gasifier and the circulating air heater. The circulating gas enters the shell of the liquefied hydrocarbon gasifier first, then enters the tube side of the circulating air heater, is heated by the circulating air heater, and enters the shell of the liquefied hydrocarbon gasifier under the action of the circulating air fan, forming a circulating gas flow path.

[0008] In this application, the low-temperature liquefied hydrocarbon gasification flow path is a flow path for realizing the gasification of liquid hydrocarbon to gaseous hydrocarbon by heating in the liquefied hydrocarbon gasifier, and the circulating gas flow path is a flow path for realizing the circulation of circulating gas between the liquefied hydrocarbon gasifier and the circulating air heater under the pressure boosting of the circulating air fan.

[0009] Optionally, the liquefied hydrocarbon gasifier and the circulating air heater are one or more of a shell-and-tube heat exchanger, a shell-and-tube heat exchanger using enhanced heat transfer, and a plate-fin heat exchanger.

[0010] Optionally, the liquefied hydrocarbon includes ethylene (CH2=CH2), propylene (CH2=CHCH3), 1-butene (CH2=CHCH2CH3), trans-2-butene (trans-CH3CH=CHCH3), cis-2-butene (cis-CH3CH=CHCH3), isobutylene (CH2=C(CH3)2), methane (CH4), ethane (CH3CH3), propane (CH3CH2CH3).

[0011] Optionally, the liquefied hydrocarbon includes a liquid hydrocarbon having a storage temperature of less than 0°C under normal pressure conditions.

[0012] Optionally, the circulating gas is nitrogen or carbon dioxide.

[0013] Optionally, the circulating gas is nitrogen.

[0014] Optionally, the heating medium of the circulating air heater includes any one of heat conducting oil, high-temperature hot water, steam, and electricity.

[0015] Optionally, the heating medium of the circulating air heater is steam.

[0016] Optionally, the temperature of the circulating gas after being heated by the circulating air heater is controlled to be 50-80°C.

[0017] Optionally, the temperature of the circulating gas after being heated by the circulating air heater is controlled to be 60°C.

[0018] Optionally, the temperature of the circulating gas after being cooled by the liquefied hydrocarbon gasifier is controlled to be 40-60°C.

[0019] Optionally, the temperature of the circulating gas after being cooled by the liquefied hydrocarbon gasifier is controlled to be 40°C.

[0020] Optionally, the temperature of the low-carbon hydrocarbon after being gasified is 10-50°C.

[0021] Optionally, the temperature of the low-carbon hydrocarbon after being gasified is 30°C.

[0022] In a second aspect, the present application provides a method for gasifying low-temperature C1-C4 liquefied hydrocarbon stored under normal pressure using the above device, which adopts the following technical solution: A method for gasifying low-temperature C1-C4 liquefied hydrocarbon stored under normal pressure using the above device, the method specifically includes the following steps: The liquefied hydrocarbon is introduced into the low-temperature storage liquefied hydrocarbon raw material tank from the outside, enters the liquefied hydrocarbon gasifier under the action of the low-temperature liquid booster pump, is gasified after transportation to the production device for use, and forms a low-temperature liquefied hydrocarbon gasification flow path; the energy required for gasification is provided by the circulating gas heated by the circulating air heater; The circulating gas enters the system first into the shell of the liquefied hydrocarbon gasifier, then into the tube side of the circulating air heater, is heated after passing through the circulating air heater, and enters the shell of the liquefied hydrocarbon gasifier under the action of the circulating air blower to form a circulating gas flow path; the circulating gas is supplemented in time by monitoring the flow of the circulating gas in the system.

[0023] In summary, the present application includes at least one of the following beneficial technical effects: The system and method provided by the present application effectively solve the frosting problem, avoid direct contact between the heat source and the liquefied hydrocarbon, are suitable for an industrial scene in which low-temperature liquid liquefied hydrocarbon is converted into gaseous state, and the nitrogen gas as a heat carrier is the circulating gas, which has high safety. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 FIG. 1 is a schematic diagram of a system for gasification of normal-temperature stored low-temperature C1-C4 liquefied hydrocarbon according to the present application.

[0025] BRIEF DESCRIPTION OF DRAWINGS: V1. Low-temperature storage liquefied hydrocarbon raw material tank; P1. Low-temperature liquid booster pump; E1. Liquefied hydrocarbon gasifier; E2. Circulating air heater; C1. Circulating air blower. DETAILED DESCRIPTION

[0026] Before describing the embodiments of the present application in detail, it should be understood that the terms used herein are for the purpose of describing specific embodiments only. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the term belongs.

[0027] It should be noted that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. Further, in the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0028] The endpoints of the ranges and any values disclosed in this application are not limited to the precise values recited. The endpoints of the ranges and values are approximations that are used in this application to enable a person of ordinary skill in the art to determine the ranges and values encompassed. Any numerical range recited in this application is intended to include all sub-ranges subsumed therein. For example, a range of "1 to 10" is intended to include all sub-ranges between and including the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum of 1 and a maximum of 10. Any maximum numerical limitation recited in this application is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this application is intended to include all higher numerical limitations subsumed therein. In this application, the use of "or" means "and / or" unless specifically stated otherwise, even though "and / or" is also typically represented simply by a "and" or "or". Unless otherwise indicated, all ranges are inclusive of the recited maximum and minimum values.

[0029] In this application, the term "comprising" or "including" is an open term, which means that it includes the recited elements, but not excluding other elements.

[0030] The application provides a system for gasification of low-temperature C1-C4 liquefied hydrocarbon stored at normal temperature. Referring to Figure 1 , the system comprises a low-temperature storage liquefied hydrocarbon raw material tank, a low-temperature liquid booster pump, a liquefied hydrocarbon gasifier, a circulating air heater and a circulating air fan connected in sequence through pipelines and necessary pipe fittings, the circulating air fan is connected with the liquefied hydrocarbon gasifier; the liquefied hydrocarbon gasifier is connected with a production device; a circulating gas supplement pipeline is arranged between the liquefied hydrocarbon gasifier and the circulating air heater.

[0031] The application also provides a method for gasification of low-temperature C1-C4 liquefied hydrocarbon stored at normal pressure by using the above device. The method specifically comprises the following steps: The liquefied hydrocarbon is introduced into the low-temperature storage liquefied hydrocarbon raw material tank from the outside world, and enters the liquefied hydrocarbon gasifier under the action of the low-temperature liquid booster pump, and is transported to the production device for use after gasification, forming a low-temperature liquefied hydrocarbon gasification flow path; the energy required for gasification is provided by the circulating gas heated by the circulating air heater; The circulating gas enters the system first into the shell of the liquefied hydrocarbon gasifier, and then into the tube side of the circulating air heater, and after being heated by the circulating air heater, enters the shell of the liquefied hydrocarbon gasifier under the action of the circulating air fan, forming a circulating gas flow path; the circulating gas is supplemented in time by monitoring the flow of the circulating gas in the system.

[0032] In order to make the purpose, technical scheme and advantages of the application clearer, the technical scheme in the embodiments of the application will be described clearly and completely. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application. The embodiments described below are exemplary and are used to explain the application, and cannot be understood as limiting the application.

[0033] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products. Unless otherwise specified, standard atmospheric pressure is 100 kPa.

[0034] The present application will be further described in detail below with reference to embodiments, comparative examples and test results.

[0035] Example 1

[0036] This embodiment provides a system for the storage and low-temperature vaporization of C1-C4 liquefied hydrocarbons at room temperature. The system is stable, safe, reliable, and industrially feasible. The object of this embodiment is propane.

[0037] like Figure 1 As shown, the system includes a cryogenic liquid propane storage tank (i.e., cryogenic liquefied hydrocarbon feedstock tank V1), a cryogenic propane booster pump (i.e., cryogenic liquid booster pump P1), a propane vaporizer (i.e., liquefied hydrocarbon vaporizer E1), a circulating air heater E2, and a circulating fan C1, which are connected in sequence through pipes and necessary fittings, flow meters, control valves, etc. The circulating fan C1 is also connected to the propane vaporizer (i.e., liquefied hydrocarbon vaporizer E1).

[0038] The cryogenic liquid propane storage tank (i.e., cryogenic liquefied hydrocarbon feedstock tank V1) is used to store cryogenic liquid propane, with an operating temperature of -45℃ and an operating pressure of atmospheric pressure. The propane vaporizer (i.e., liquefied hydrocarbon vaporizer E1) is connected to the production unit, and the vaporized propane can be transported to subsequent production units to form a cryogenic propane vaporization flow path.

[0039] The circulating air heater E2 provides heat through a heating medium (steam). Simultaneously, a circulating gas replenishment line is installed between the propane vaporizer (i.e., the liquefied hydrocarbon vaporizer E1) and the circulating air heater E2 to introduce or replenish fresh nitrogen. The appropriate amount of fresh nitrogen is replenished by adjusting the opening of the circulating gas replenishment line based on the circulating nitrogen flow rate, thus forming a circulating gas flow path.

[0040] The method for vaporizing low-temperature C1-C4 liquefied hydrocarbons stored at room temperature using the above system specifically includes the following two flow paths: (1) The cryogenic propane vaporization flow path is as follows: Cryogenic liquid propane is transported from outside the boundary (e.g., tank truck) to the cryogenic liquid propane storage tank at a mass flow rate of 15937 kg / h. After being pressurized by the cryogenic propane booster pump, it is vaporized into gaseous propane in the propane vaporizer. The vaporized propane is then transported to subsequent production units for use. The temperature of the vaporized propane is 10℃. The heat required for the propane vaporizer comes from the circulating gas heated by steam.

[0041] (2) The circulating gas circulation flow path is as follows: the circulating nitrogen gas introduced into the system first passes through the propane gasifier shell at a temperature of 40°C, then passes through the tube side of the circulating air heater E2, and is heated to 100°C by low-pressure saturated steam, and then enters the shell of the propane gasifier after being pressurized by the circulating air blower C1 to provide heat source for gasification. The required flow rate of 0.6 MPaG circulating nitrogen gas is 104497.5 Nm³ / h, and the flow rate of 0.8 MPaG saturated steam is 4705.9 kg / h. Fresh nitrogen gas is appropriately supplemented by detecting the flow rate of circulating nitrogen gas in the system.

[0042] Example 2

[0043] The present embodiment provides a system for gasifying low-temperature C1-C4 liquefied hydrocarbon stored at room temperature. The system is stable, safe and reliable in operation, and is feasible for industrialization. The object in the present embodiment is 1-butene (hereinafter referred to as butene).

[0044] As shown in Figure 1 , the system comprises a low-temperature liquid butene storage tank (i.e. a low-temperature storage liquefied hydrocarbon raw material tank V1), a low-temperature butene booster pump (i.e. a low-temperature liquid booster pump P1), a butene gasifier (i.e. a liquefied hydrocarbon gasifier E1), a circulating air heater E2, and a circulating air blower C1, which are connected in sequence by pipelines and necessary pipe fittings, flow meters, control valves, etc., and the circulating air blower C1 is also connected to the butene gasifier (i.e. the liquefied hydrocarbon gasifier E1).

[0045] The low-temperature liquid butene storage tank (i.e. the low-temperature storage liquefied hydrocarbon raw material tank V1) is used to store low-temperature liquid butene, and the operating temperature is -30°C and the operating pressure is normal pressure. The butene gasifier (i.e. the liquefied hydrocarbon gasifier E1) is connected to a production device, and the gasified butene can be transported to the subsequent production device to form a low-temperature butene gasification flow path.

[0046] The circulating air heater E2 provides heat by heating medium (steam). Meanwhile, a circulating gas supplement pipeline is also provided between the butene gasifier (i.e. the liquefied hydrocarbon gasifier E1) and the circulating air heater E2 for introducing or supplementing fresh nitrogen gas. The fresh nitrogen gas is supplemented by adjusting the opening of the circulating gas supplement pipeline to supplement appropriate fresh nitrogen gas by monitoring the flow rate of the circulating nitrogen gas to form a circulating gas flow path.

[0047] The method for gasifying low-temperature C1-C4 liquefied hydrocarbon stored at room temperature using the above-mentioned system specifically includes the following two flow paths: (1) The low-temperature butene gasification flow path is as follows: the low-temperature liquid butene is transported from the outside (for example: a tank car) to the low-temperature liquid butene storage tank at a mass flow rate of 10500 kg / h, and is gasified into gaseous butene in the butene gasifier after being pressurized by the low-temperature butene booster pump, and the gasified butene is transported to the subsequent production device for use. The temperature of the gasified butene is 25°C. The heat required by the butene gasifier is derived from the circulating gas heated by steam.

[0048] (2) The circulating gas circulation flow path is as follows: the circulating nitrogen gas introduced into the system first passes through the butene gasifier shell at a temperature of 40°C, then passes through the tube side of the circulating air heater E2, and is heated to 100°C by low-pressure saturated steam, and then enters the shell of the butene gasifier after being pressurized by the circulating air blower C1 to provide heat source for gasification. The required flow rate of 0.6 MPaG circulating nitrogen gas is 66408.4 Nm³ / h, and the flow rate of 0.8 MPaG saturated steam is 2990.8 kg / h. Fresh nitrogen gas is appropriately supplemented by detecting the flow rate of circulating nitrogen gas in the system.

[0049] Example 3

[0050] The present embodiment provides a system for gasifying low-temperature C1-C4 liquefied hydrocarbon stored at room temperature. The system is stable, safe and reliable in operation, and is feasible for industrialization. The object in the present embodiment is ethylene.

[0051] As shown in Figure 1 , the system comprises, in sequence, a low-temperature liquid ethylene storage tank (i.e., a low-temperature storage liquefied hydrocarbon raw material tank V1), a low-temperature ethylene booster pump (i.e., a low-temperature liquid booster pump P1), an ethylene gasifier (i.e., a liquefied hydrocarbon gasifier E1), a circulating air heater E2, and a circulating air blower C1, and the circulating air blower C1 is further connected to the ethylene gasifier (i.e., the liquefied hydrocarbon gasifier E1).

[0052] The low-temperature liquid ethylene storage tank (i.e., the low-temperature storage liquefied hydrocarbon raw material tank V1) is used to store low-temperature liquid ethylene, and the operating temperature is -105°C and the operating pressure is normal pressure. The ethylene gasifier (i.e., the liquefied hydrocarbon gasifier E1) is connected to a production device, and the gasified ethylene can be transported to the subsequent production device to form a low-temperature ethylene gasification flow path.

[0053] The circulating air heater E2 provides heat through a heating medium (steam). Meanwhile, a circulating gas supplement pipeline is further provided between the ethylene gasifier (i.e., the liquefied hydrocarbon gasifier E1) and the circulating air heater E2, for introducing or supplementing fresh nitrogen gas. The fresh nitrogen gas is supplemented by adjusting the opening degree of the circulating gas supplement pipeline according to the flow rate of the circulating nitrogen gas to form a circulating gas flow path.

[0054] The method for gasifying low-temperature C1-C4 liquefied hydrocarbon stored at room temperature by using the above-mentioned system specifically comprises the following two flow paths: (1) The low-temperature ethylene gasification flow path is as follows: the low-temperature liquid ethylene is transported from the outside (for example, a tank car) to the low-temperature liquid ethylene storage tank at a mass flow rate of 6500 kg / h, is pressurized by the low-temperature ethylene booster pump, and is gasified into gaseous ethylene in the ethylene gasifier. The gasified ethylene is transported to the subsequent production device for use. The temperature of the gasified ethylene is 15°C. The heat required by the ethylene gasifier is derived from the circulating gas heated by steam.

[0055] (2) The circulating gas circulation flow path is as follows: the circulating nitrogen gas introduced into the system first passes through the ethylene vaporizer shell, the 40°C, 54718.6Nm³ / h, 0.6MPaG circulating nitrogen gas from the ethylene vaporizer shell passes through the tube side of the circulating air heater E2, and after being heated to 100°C by 2407.4kg / h, 0.8MPaG saturated steam, it is pressurized by the circulating air blower C1 and enters the shell of the ethylene vaporizer to provide heat source for gasification. The flow rate of the circulating nitrogen gas in the system is detected to appropriately supplement fresh nitrogen gas.

[0056] Example 4

[0057] The present embodiment provides a system for gasifying low-temperature C1-C4 liquefied hydrocarbon stored at room temperature. The system is stable, safe and reliable in operation and feasible for industrialization. The object in the present embodiment is propylene.

[0058] As shown in Figure 1 , the system comprises, in sequence, a low-temperature liquid propylene storage tank (i.e. a low-temperature storage liquefied hydrocarbon raw material tank V1), a low-temperature propylene booster pump (i.e. a low-temperature liquid booster pump P1), a propylene vaporizer (i.e. a liquefied hydrocarbon vaporizer E1), a circulating air heater E2, and a circulating air blower C1, and the circulating air blower C1 is further connected to the propylene vaporizer (i.e. the liquefied hydrocarbon vaporizer E1).

[0059] The low-temperature liquid propylene storage tank (i.e. the low-temperature storage liquefied hydrocarbon raw material tank V1) is used for storing low-temperature liquid propylene, and the operating temperature is -60°C and the operating pressure is normal pressure. The propylene vaporizer (i.e. the liquefied hydrocarbon vaporizer E1) is connected to a production device, and the vaporized propylene can be transported to a subsequent production device to form a low-temperature propylene gasification flow path.

[0060] The circulating air heater E2 provides heat through a heating medium (steam). Meanwhile, a circulating gas supplement pipeline is further provided between the propylene vaporizer (i.e. the liquefied hydrocarbon vaporizer E1) and the circulating air heater E2, for introducing or supplementing fresh nitrogen gas. The fresh nitrogen gas is supplemented by adjusting the opening degree of the circulating gas supplement pipeline according to the flow rate of the circulating nitrogen gas to supplement appropriate fresh nitrogen gas, so as to form a circulating gas flow path.

[0061] The method for gasifying low-temperature C1-C4 liquefied hydrocarbon stored at room temperature by using the above system specifically comprises the following two flow paths: (1) The low-temperature propylene gasification flow path is as follows: the low-temperature liquid propylene is transported from the outside (for example: a tank car) to the low-temperature liquid propylene storage tank at a mass flow rate of 2000kg / h, and is pressurized by the low-temperature propylene booster pump and then vaporized into gaseous propylene in the propylene vaporizer. The vaporized propylene is transported to a subsequent production device for use. The temperature of the vaporized propylene is 25°C. The heat required by the propylene vaporizer is derived from the circulating gas heated by steam.

[0062] (2) The circulating gas circulation flow path is as follows: the circulating nitrogen gas entering the system first passes through the propylene gasifier shell at a temperature of 45 DEG C, then passes through the tube side of the circulating air heater E2, and is heated to 80 DEG C by low-pressure saturated steam, and then enters the shell of the propylene gasifier by the circulating fan C1 to provide heat source for gasification. The required flow rate of 0.6 MPaG circulating nitrogen gas is 25203.2 Nm3 / h, and the flow rate of 0.8 MPaG saturated steam is 663.6 kg / h. Fresh nitrogen gas is appropriately supplemented by detecting the flow rate of the circulating nitrogen gas in the system.

[0063] In summary, the system and method provided by the application effectively solve the problem of frosting, avoid direct contact between the heat source and the liquefied hydrocarbon, are suitable for the industrial scene of converting low-temperature liquid liquefied hydrocarbon into gaseous state, and the nitrogen gas as the heat carrier is a circulating gas, which has high safety.

[0064] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the different embodiments or examples described in the present specification and the features of the different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0065] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A system for storing and vaporizing C1-C4 liquefied hydrocarbons at room temperature, characterized in that, The system includes a cryogenic storage tank for liquefied hydrocarbon feedstock (V1), a cryogenic liquid booster pump (P1), a liquefied hydrocarbon vaporizer (E1), a circulating air heater (E2), and a circulating fan (C1) connected in sequence by pipes and necessary fittings. The circulating fan (C1) is connected to the liquefied hydrocarbon vaporizer (E1). The liquefied hydrocarbon vaporizer (E1) is connected to the production unit; liquefied hydrocarbons are introduced from the outside into the cryogenic storage liquefied hydrocarbon raw material tank (V1), and under the action of the cryogenic liquid booster pump (P1), they enter the liquefied hydrocarbon vaporizer (E1) for vaporization, and after vaporization, they are transported to the production unit for use, forming a cryogenic liquefied hydrocarbon vaporization flow path; the energy required for vaporization is provided by the circulating gas heated by the circulating air heater (E2). A circulating gas supply pipeline is provided between the liquefied hydrocarbon vaporizer (E1) and the circulating air heater (E2). After entering the system, the circulating gas first enters the shell of the liquefied hydrocarbon vaporizer (E1), and then enters the tube of the circulating air heater (E2). After being heated by the circulating air heater (E2), it enters the shell of the liquefied hydrocarbon vaporizer (E1) under the action of the circulating fan (C1), forming a circulating gas flow path.

2. The system according to claim 1, characterized in that, The liquefied hydrocarbon vaporizer (E1) and the circulating air heater (E2) are one or more of the following: shell and tube heat exchangers, shell and tube heat exchangers with enhanced heat transfer, and plate and fin heat exchangers.

3. The system according to claim 1, characterized in that, The liquefied hydrocarbons include ethylene, propylene, 1-butene, isobutene, methane, ethane, and propane.

4. The system according to claim 1, characterized in that, The liquefied hydrocarbons include liquid hydrocarbons stored at temperatures below 0°C under normal pressure.

5. The system according to claim 1, characterized in that, The circulating gas is either nitrogen or carbon dioxide.

6. The system according to claim 1, characterized in that, The heating medium of the circulating air heater (E2) includes any one of heat transfer oil, high-temperature hot water, steam, and electricity.

7. The system according to claim 1, characterized in that, The temperature of the circulating gas after being heated by the circulating air heater (E2) is controlled at 50-80℃.

8. The system according to claim 1, characterized in that, The temperature of the circulating gas after being cooled by the liquefied hydrocarbon vaporizer (E1) is controlled at 40-60℃.

9. The system according to claim 1, characterized in that, The temperature of the gasified low-carbon hydrocarbons is 10-50℃.

10. A method for vaporizing cryogenically stored C1-C4 liquefied hydrocarbons at atmospheric pressure using the system according to any one of claims 1-9, characterized in that, The method specifically includes the following steps: Liquefied hydrocarbons are introduced from the outside into the cryogenic storage liquefied hydrocarbon raw material tank (V1), and under the action of the cryogenic liquid booster pump (P1), they enter the liquefied hydrocarbon vaporizer (E1) for vaporization. After vaporization, they are transported to the production unit for use, forming a cryogenic liquefied hydrocarbon vaporization flow path. The energy required for vaporization is provided by the circulating gas heated by the circulating air heater (E2). After entering the system, the circulating gas first enters the shell of the liquefied hydrocarbon vaporizer (E1), and then enters the tube of the circulating air heater (E2). After being heated by the circulating air heater (E2), it enters the shell of the liquefied hydrocarbon vaporizer (E1) under the action of the circulating fan (C1), forming a circulating gas flow path. The circulating gas is replenished in a timely manner by monitoring the flow rate of the circulating gas in the system.

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