Framework for a gas liquefier
A modular framework for gas liquefaction systems addresses the challenge of integrating late-arriving equipment by optimizing space and facilitating hydrostatic pressure, enabling efficient and crane-free installation and improved liquefaction efficiency.
Patent Information
- Application Number
- FR2023002424
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-03-16
- Publication Date
- 2025-04-18
- Estimated Expiration
- 2043-03-16
AI Technical Summary
Existing gas liquefaction systems face challenges in efficiently integrating late-arriving equipment, such as turbines, without requiring heavy machinery like cranes, and optimizing space utilization for efficient gas liquefaction at cryogenic temperatures.
A modular framework for gas liquefaction systems that includes a support structure for heat exchangers and turbines, allowing for easy installation of late-arriving equipment and optimizing space by positioning exchangers at elevated heights, with compartments designed for thermal insulation and fluid connectivity, facilitating hydrostatic pressure for gas transport.
Enables efficient installation of late-arriving equipment without cranes and maximizes space utilization, enhancing the production of liquefied gas with significant hydrostatic pressure, reducing the need for large pumps and optimizing the liquefaction process.
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Abstract
Description
Title of the invention: Frame for a gas liquefier
[0001] The present invention relates to a framework for a liquefier of a gas liquefying at a cryogenic temperature, for example nitrogen, hydrogen.
[0002] FR2706025 describes an air separation apparatus by cryogenic distillation comprising a framework containing the heat exchangers, subcoolers, valves, cryogenic pumps, turbines and pipes to connect them to each other. A distillation column is located outside this framework.
[0003] Nitrogen liquefiers are known from US20220404094.
[0004] An object of the present invention is to reduce the ground footprint of a liquefier and to facilitate the late installation of any equipment, for example a turbine, in the frame, even if it is delivered late.
[0005] Indeed, the turbine is often delivered after the arrival of other elements and it will be desirable to find a way to install it by reducing the number of operations necessary and in particular by avoiding the use of a crane, in the workshop, an overhead crane or a simple load lift can be used for the installation in place of the equipment.
[0006] It is advantageous to use a support means for the heat exchanger which also serves as a framework for the entire module. As a result, this framework contains other elements of the liquefier allowing assembly in the workshop by qualified personnel of the assembly, the connections between the exchanger and the other elements of the framework, for example interconnection box, piping, instrumentation and electricity are also carried out by the manufacturing workshop.
[0007] In addition to reducing the footprint, positioning the exchangers at an elevation of at least 4 m above the ground allows liquid to be produced, thus creating hydrostatic pressure, which can be used to transport the gas or reduce the size of a pump used to pressurize the liquid.
[0008] According to an object of the invention, there is provided a framework to be part of a liquefier of a gas which liquefies at a cryogenic temperature, the framework being substantially in the form of an elongated parallelepiped and having a main axis as well as two ends, the framework not containing a distillation column but containing: i. At one end at least one plate and fin heat exchanger, each plate having a length and a width, and the plates being arranged with their length parallel to the axis of the frame ii. A pipe for sending a gas to be liquefied to the at least one heat exchanger iii. A pipe for removing a cooled or even liquefied gas from the at least one heat exchanger iv. At least one turbine, the turbine being fixed on a support and being arranged to drive a compressor arranged outside the frame, the turbine being connected to the at least one exchanger to send to the turbine a gas to be expanded cooled or heated in the at least one heat exchanger and / or to send from the turbine to the at least one heat exchanger a gas expanded in the turbine v. at least one cooler connected to cool compressed gas in the compressor vi. means for supplying a refrigerant to the cooler vii. a) the turbine is located at another end of the frame and the cooler is located between the turbine and at least one heat exchanger or
[0009] b) the cooler is located at another end of the frame and the turbine is located between the cooler and at least one heat exchanger.
[0010] According to other optional aspects, which can be combined with each other in any way compatible with logic and science: • the frame comprises at least one partition dividing the frame into at least two parts, the partition having the shape of a rectangular plate arranged perpendicular to the axis of the frame, the partition serving as a support for the turbine if the cooler is at the other end of the frame or for the cooler if the turbine is at the other end of the frame, the turbine and the cooler being separated from each other by the partition. • the frame comprises at least two partitions dividing the frame into at least three parts, the partitions having the shape of a rectangular plate arranged perpendicular to the axis of the frame, one of the partitions serving as a support for the turbine if the cooler is at the other end of the frame or for the cooler if the turbine is at the other end of the frame, the turbine and the cooler being separated from each other by the partition serving as a support. • the frame comprising fixing feet connected to the other end of the frame to place the frame on a foundation. • the frame comprising means for fluidly connecting the exchanger with the compressor to bring a cooled gas in the exchanger to the compressor. • the frame comprising means for fluidly connecting the exchanger with the turbine to bring an expanded gas in the turbine to the at least one exchanger. • the frame is divided into at least three compartments, each compartment having a dimension which is a part of the length of the frame, the at least one heat exchanger being in one of the at least three compartments, the turbine in another of the at least three compartments and the at least one cooler in yet another of the at least three compartments. • the frame comprising a fourth compartment, empty of any heat exchanger and turbine, containing connection pipes between the heat exchanger and another element which may be at least one turbine. • the turbine is located at another end of the frame and is connected to the fourth compartment through a compartment arranged side by side with the compartment containing the cooler. • the frame has a length of at least 5 m, the cooler and the turbine occupying a part of the length of the frame equal to at least 4 m. • the turbine is connected to supply cold to at least one heat exchanger. • the frame is formed from a single piece.
[0011] According to another object of the invention, there is provided a liquefier comprising a frame as described above, positioned with its main axis vertical, the at least one heat exchanger being located above the at least one turbine and the at least one heater, means for sending a gas to be liquefied to the heat exchanger in the frame and means connected to the heat exchanger for removing a liquefied gas from the frame.
[0012] According to another object of the invention, there is provided an apparatus for separating air by cryogenic distillation comprising a column system, a liquefier as described above and means for sending a nitrogen-enriched gas to the liquefier from the column system as gas to be liquefied and optionally means for sending a gas liquefied in the liquefier to the column system.
[0013] The invention will be described in more detail with reference to the figures where:
[0014] [Fig-1] is a longitudinal section of a frame according to the invention in position vertical.
[0015] [Fig.2] is a longitudinal section of a frame variant according to the invention, in manufacturing and transport in horizontal position.
[0016] [Fig.3] is a longitudinal section of the frame variant according to [Fig.2], showing on-site setup.
[0017] [Fig.l] shows a nitrogen liquefier frame 1, installed with its main axis vertical. One end of the frame is located a few meters from the ground while the opposite end is anchored to the ground.
[0018] The frame O has a substantially parallelepiped shape with a length, a width and a height. The section of the frame is rectangular, or even square.
[0019] As illustrated here, the substantially parallelepiped frame actually comprises two parallelepipeds which may be of different widths, joined to each other preferably welded or bolted, compartments 1 and 4 forming one parallelepiped and compartments 2 and 3 the other. It is preferable that the wider parallelepiped (here the one containing compartments 2 and 3) is arranged below the other for reasons of stability.
[0020] At the top of the frame in a first compartment 1 is at least one heat exchanger E which serves to cool the gas to be liquefied to a temperature close to liquefaction or even to the liquefaction temperature. The exchangers are oriented with their hot end at the top and the cold end at the bottom, when the frame is placed vertically. A pipe C brings the gas to be liquefied to the hot end of the heat exchanger, this pipe C being able to be connected to an air separation device producing gaseous nitrogen.
[0021] The first compartment 1 is thermally insulated by means of a powdered insulator such as perlite.
[0022] Below the first compartment 1 there is possibly an auxiliary compartment 4 also called an interconnection box, divided from the first compartment by a wall and containing essentially powdered insulation or rock wool. The auxiliary compartment 4 does not contain heat exchangers or a turbine. It mainly contains connecting pipes which pass through the partition via openings in it. These pipes connect the heat exchanger E with a turbine, located in a third compartment 3 located at the end of the frame O. The turbine is connected to the at least one exchanger to send to the turbine a gas to be expanded cooled or heated in the at least one heat exchanger and / or to send from the turbine to the at least one heat exchanger a gas expanded in the turbine.
[0023] The heat exchanger E is a plate and fin exchanger, composed of a stack of plates, each plate being separated from at least one adjacent plate by fins, each plate having a length and a width, and the plates being arranged with their length parallel to the axis of the frame.
[0024] In the figure, it can be seen that the heat exchanger comprises two bodies, each of which can be considered as a heat exchanger and each of which is composed of a stack of plates, each plate having a length and a width, and the plates being arranged with their length parallel to the axis of the frame.
[0025] The turbine drives a compressor of the liquefier by means of a shaft, the compressor being located outside the frame O. The compressor is used to compress a cooled or heated gas in the at least one heat exchanger.
[0026] At least a portion of the compressed gas in the compressor may be expanded in the turbine, according to the methods.
[0027] In a second compartment 2, placed between the third compartment 3 and the auxiliary compartment 4, there is a cooler R supplied with a refrigerant such as water to cool the compressed gas in the compressor driven by the turbine of the third compartment 3. There are therefore pipes passing in the partition between the second and third compartments 2, 3. This partition must possibly be reinforced to support the weight of the cooler R. Since the cooler R operates at ambient temperatures or temperatures above 20 °C, it does not need to be thermally insulated or possibly includes protection to prevent personnel from touching the hot parts. The frame is preferably not covered with sheets of metal around the cooler, which is thus in the open air.
[0028] To allow direct access of fluids coming from at least one exchanger E to the turbine T and going from the turbine T to the at least one exchanger, a compartment 5 extends on one side of the frame between the second and fourth compartments, running along the second compartment 2. Thus the fluids do not need to pass through the second compartment 2, the pipes passing only through the compartment 5. As the pipes of the compartment are L-shaped, this allows more flexibility when the exchangers heat up and cool down, causing expansions and shrinkage.
[0029] This compartment 5 is thermally insulated with particulate insulation or rock wool and must therefore be hermetically sealed, just like compartments 1 and 4 (if present).
[0030] The framework does not contain a distillation or washing column, the liquefier itself not containing one.
[0031] A feed gas is sent into the frame O, cooled in the at least one exchanger E, according to a variant at least a portion of the feed gas is compressed in the compressor driven by the turbine T and then cooled in the cooler R, at least a portion of the feed gas is expanded in the turbine T. The gas sent to the turbine T preferably comes from the cooler R.
[0032] A portion of the feed gas liquefies either in the exchanger or downstream of it and constitutes the product of the process.
[0033] The feed gas may be nitrogen, hydrogen, natural gas.
[0034] In this case, it is common to associate this type of liquefier with a device of separation of air by cryogenic distillation, of gaseous nitrogen from the apparatus of separation of air constituting the feed gas to the liquefier and at least a portion of the liquid nitrogen formed being returned to the air separation apparatus.
[0035] It is noted that the exchangers are arranged in height, with their length in the direction of the main axis of the frame. Thus the space below the exchangers is used in a clever way. In addition, given that the frame has a length of at least 10 m, the cooler and the turbine occupying a part of the length of the frame equal to at least 4 m, when the frame is placed vertically, the cold end of at least one exchanger is at least 6 m from the ground. Thus a liquefied gas leaving the cold end has a significant hydrostatic pressure, facilitating its sending elsewhere and making it possible to reduce the size of a pump if present.
[0036] Compartments 1 and 4 being thermally insulated with perlite, the frame is covered with sheet metal. For compartments 2 and 3 where the thermal insulation, if present, is generally rock wool, the frame may not be covered with sheet metal.
[0037] It is recommended to leave in the frame an opening large enough to allow the turbine to enter if it arrives on site late. Since compartment 5 of turbine T is at ground level, this introduction is particularly easy and does not require the use of a crane.
[0038] The turbine T is connected to supply cold to the at least one heat exchanger E.
[0039] The frame O of [Fig.2] differs from that of [Fig.l] in that compartments 2 and 3 are reversed, the cooler R being located at the end of the frame in compartment 2 and the turbine M between compartment 4 and compartment 2 of the cooler R. Compartment 3 of the turbine T being at a height greater than 2m, this introduction does not require the use of a crane.
[0040] In manufacturing and during transport ([Fig.2]), the frame is arranged with its main axis horizontal. The lifting lugs L can be seen at the end of the frame where the exchangers E are located. Such lugs can be found at both ends of the frame O.
[0041] When installed on site ([Fig.3]), these ears or attachments L allow a crane G to lift the frame and install it with its main axis vertical. Feet P allow the frame to be fixed to the ground or to a foundation.
[0042] The frame O can take the form of a standardized container to facilitate transport.
[0043] The framework O comprises means for sending a sweeping gas to compartments 1, 4 and 5 (if present for the last two).
[0044] The turbine can be transported in the frame or else added to the frame on site. In the second case, it is necessary to calculate the dimensions and rigidities of the frame for both cases: the one where the turbine is present and the one where it is absent.
[0045] The frame can be lifted in a single operation, preferably being formed in one piece.
Claims
1. Claims Liquefier of a gas which liquefies at a cryogenic temperature comprising an assembly comprising a framework (O), the framework being substantially in the shape of an elongated parallelepiped and having a main axis corresponding to its length as well as two ends, the framework not containing a distillation column, and inside the framework: i. At one end of the frame at least one plate and fin heat exchanger (E), each plate having a length and a width, and the plates being arranged with their length parallel to the axis of the frame ii. A pipe (C) for sending a gas to be liquefied to the at least one heat exchanger iii. A pipe for removing a cooled or even liquefied gas from the at least one heat exchanger iv. A support mounted in the frame v. At least one turbine (M), the turbine being fixed on the support and being arranged to drive a compressor arranged outside the frame, the turbine being connected to the at least one exchanger to send to the turbine a gas to be expanded cooled or heated in the at least one heat exchanger and / or to send from the turbine to the at least one heat exchanger a gas expanded in the turbine vi. at least one cooler (R) connected to cool compressed gas in the compressor vii. means for supplying a refrigerant to the cooler and viii. (a) the turbine is located at another end of the frame and the cooler is located between the turbine and the at least one heat exchanger or (b) the cooler is located at another end of the frame and the turbine is located between the cooler and at least one heat exchanger, the frame being positioned with its main axis vertical, the at least one heat exchanger (E) being located above the at least one turbine (M) and the at least one cooler (R), means (C) for sending a gas to be liquefied to the heat exchanger in the frame and means connected to the heat exchanger for removing a liquefied gas from the frame.
2. Liquefier according to claim 1 comprising at least one partition dividing the frame into at least two parts (1, 2, 3, 4, 5), the partition having the shape of a rectangular plate arranged perpendicular to the axis of the frame (0), the partition serving as a support for the turbine (M) if the cooler (R) is at the other end of the frame or for the cooler if the turbine is at the other end of the frame, the turbine and the cooler being separated from each other by the partition.
3. A liquefier according to claim 1 or 2 comprising fixing feet (P) connected to the other end of the frame (0) for placing the frame on a foundation.
4. Liquefier according to one of the preceding claims comprising means for fluidly connecting the exchanger with the compressor to bring a cooled gas in the exchanger to the compressor.
5. Liquefier according to one of the preceding claims comprising means for fluidically connecting the exchanger with the turbine to bring a gas expanded in the turbine towards the exchanger.
6. Liquefier according to one of the preceding claims in which the framework is divided into at least three compartments (1, 2, 3), each compartment having a dimension which is a part of the length of the framework, the at least one heat exchanger (E) being in one of the at least three compartments (1), the turbine (M) in another of the at least three compartments (3) and the at least one cooler (R) in yet another (2) of the at least three compartments, the compartments containing the turbine and the at least one cooler forming a parallelepiped wider than that formed by the compartment containing the heat exchanger.
7. Liquefier according to claim 6 comprising a fourth compartment (4), empty of any heat exchanger and turbine, containing connection pipes between the at least one heat exchanger (E) and another element which may be the at least one turbine (M).
8. Liquefier according to claim 7 in which the turbine (M) is located at another end of the frame and is connected to the fourth compartment (4) through a compartment (5) arranged side by side with the compartment (2) containing the cooler (R).
9. Liquefier according to one of the preceding claims in which the frame (0) has a length of at least 10 m, the cooler (R) and the turbine (M) occupying a part of the length of the frame equal to at least 4 m.
10. Apparatus for separating air by cryogenic distillation comprising a column system, a liquefier according to one of the preceding claims and means (C) for sending a nitrogen-enriched gas to the liquefier from the column system as gas to be liquefied.
11. Apparatus according to claim 10 comprising means for sending a liquefied gas in the liquefier to the column system.