Vaporizer for vaporizing a liquid such as liquified natural gas and method of manufacturing the same

Abstract

A vaporizer for vaporizing a liquid such as liquified natural gas, comprising: an inlet, an outlet and a heat exchanger, having an axis, therebetween; wherein the heat exchanger defines flow of a fluid therethrough; and wherein the flow of the fluid includes transverse flow of the fluid in one dimension and / or in two dimensions.

Description

[0001] VAPORIZER FOR VAPORIZING A LIQUID SUCH AS LIQUIFIED NATURAL GAS AND METHOD OF MANUFACTURING THE SAME

[0002] FIELD

[0003] The present invention relates to vaporizers for vaporization of liquids and to the design, manufacture and / or use of such vaporizers.

[0004] BACKGROUND

[0005] Typically, compositional analysis of a cryogenic liquid, for example a cryogenic liquid mixture comprising a plurality of cryogenic liquid components, is performed on a vapor sample thereof, thereby requiring vaporization (also known as gasification or regasification) of the cryogenic liquid. However, vaporization of the cryogenic liquid may result in errors in the compositional analysis, for example due to differences in vaporization of the plurality of cryogenic liquid components.

[0006] Hence, there is a need to improve compositional analysis of liquids, for example cryogenic liquids.

[0007] SUMMARY OF THE INVENTION

[0008] A first aspect provides a vaporizer for vaporizing a liquid such as liquified natural gas, comprising: an inlet, an outlet and a heat exchanger, having an axis, therebetween; wherein the heat exchanger defines flow of a fluid therethrough; and wherein the flow of the fluid includes transverse flow of the fluid in one dimension and / or in two dimensions.

[0009] A second aspect provides a method of vaporizing a liquid such as liquified natural gas, comprising: vaporizing the liquid using a heat exchanger by flowing fluid thereof therethrough; wherein flowing the fluid includes transversely flowing the fluid in one dimension and / or in two dimensions.

[0010] A third aspect provides a computer-implemented method of designing a heat exchanger for a vaporizer for vaporizing a liquid such as liquified natural gas, comprising: modelling vaporization of the liquid using a heat exchanger comprising simulating flow of a fluid through the heat exchanger and heat exchange therewith; and adapting the heat exchanger based on a result of the modelling.

[0011] A fourth aspect provides an additive manufacturing model or file thereof, for example an STL file, of a heat exchanger designed according to the third aspect. A fifth aspect provides a method of manufacturing a heat exchanger designed according to the third aspect, the method comprising: additive manufacturing the heat exchanger, for example using an additive manufacturing model or file thereof according to the fourth aspect.

[0012] A sixth aspect provides incorporating vacuum insulation to optimize heat transfer in a portion of a heat exchanger for a vaporizer for vaporizing a liquid such as liquified natural gas to improve vaporizer efficiency.

[0013] A seventh aspect provides a method of providing a heat exchanger for a vaporizer for vaporizing a liquid such as liquified natural gas, for example according to the first aspect, the method comprising: designing the heat exchanger, for example according to the third aspect; additive manufacturing the designed heat exchanger, for example according to the fifth aspect; wherein designing the heat exchanger and / or additive manufacturing the heat exchanger comprises incorporating vacuum insulation to optimize heat transfer in a portion of the heat exchanger, for example according to the sixth aspect.

[0014] DETAILED DESCRIPTION OF THE INVENTION

[0015] Vaporizer

[0016] The first aspect provides a vaporizer for vaporizing a liquid such as liquified natural gas, comprising: an inlet, an outlet and a heat exchanger, having an axis therebetween; wherein the heat exchanger defines flow of a fluid therethrough; and wherein the flow of the fluid includes transverse flow of the fluid in one dimension and / or in two dimensions.

[0017] “Vaporizing” means causing or enabling the phase transition from a liquid phase to a vapor or gas phase. Here, vaporizing may involve evaporation, boiling, or gasification and may involve an element, compound, mixture, or the like. Vaporizing is the act of vaporization, which may occur to different elements, compounds, or mixtures at different temperatures, pressures, concentrations, or other variable conditions. Here, “liquid phase” may include liquid suspensions, mixtures, solutions, colloids, emulsions, sols, or the like allowing for fluid motion through the vaporizer inlet in a liquid state at the operating temperature of the vaporizer. “Vapor or gas phase” may include gaseous suspensions, colloids, and aerosols wherein a portion of a mixture has vaporized into a dispersion medium and another portion of a mixture remains as a dispersed liquid or solid.

[0018] “A liquid” means a nearly incompressible fluid that conforms to the shape of its container but retains a nearly constant volume independent of pressure. Liquids may include liquid suspensions, mixtures, solutions, colloids, emulsions, sols, or the like allowing for fluid motion through the vaporizer inlet at the operating temperature of the vaporizer. “Liquified natural gas” (“LNG”) is natural gas (i.e., fossil gas or methane gas) which has been cooled to liquid form. The vaporizers here are suitable for vaporizing LNG but may also be suitable for other applications. As described below, the vaporizer may be designed or employed for vaporizing other liquids in other applications.

[0019] The inlet allows fluid to enter the vaporizer. An “inlet” may include one or more valves, flow regulators, flow meters, thermometers, sensors, and / or other devices known in the art to adjust or measure the state or flow of liquids into the vaporizer. The inlet may be directly attached to an “in-line” sample probe that provides a representative liquid sample, or to any suitable process connection providing an appropriate liquid source in the required state. A in-line sampler probe may be inserted to draw liquid from a tank, pipe, or other source. In one example, the inlet is configured to draw liquid from a bidirectional sample probe that can be installed directly into a liquid pipeline, such as an LNG pipeline. The bi-directional sample probe may allow for the provision of liquid without any change of state from a source flow for vaporization and sampling.

[0020] The outlet allows fluid to exit the vaporizer. An “outlet” may include one or more valves, flow regulators, flow meters, thermometers, sensors, and / or other devices known in the art to adjust or measure the state or flow of fluids out from the vaporizer. The outlet may include a thermal probe to measure temperature inside the vaporizer near the outlet point. The outlet may also lead directly to a device for collection of samples or on-line analysis of gasses, such as a gas chromatograph or a calorimeter.

[0021] In one example, the heat exchanger comprises an interior wall containing the volume for vaporization between the inlet and the outlet. The heat exchanger “axis” may run directly between the inlet and the outlet or may run in a different direction. The shape of the heat exchanger defines the flow of the fluid along the axis and also between the inlet and outlet.

[0022] The heat exchanger defines the flow of the fluid from the inlet to the outlet, but importantly also includes transverse flow of the fluid in at least one dimension. In only one dimension, the transverse flow may be described as zig-zag or boustrophedonic along the axis. In two dimensions, the transverse flow may be described as helical or helicoid along the axis. In one example, the heat exchanger provides a helical heat exchanger surface. In one example, the helical heat exchanger surface isas an irregular helix. In one example, the heat exchanger provides a toroidal void space between its surfaces such that the toroidal radius is perpendicular to the axial flow of fluid from the inlet to the outlet.

[0023] “Axial flow” means fluid motion along the axis of a cylindrical or rotational system. It is commonly encountered in scenarios like water flowing through pipes or air flowing through turbines. It is contemplated that vaporizers of the present invention need not be cylindrical or rotational, and could be rectangular, hexagonal, or irregular. The axis also is contemplated to include non-linear axes which would generally define an unobstructed path from the inlet to the outlet through the general shape of the heat exchanger. In all such cases, “axial flow” generally refers to flow parallel to the axis. Generally, when fluid motion is parallel to the axis of flow, such flow can be described as laminar.

[0024] “Transverse flow” means fluid motion perpendicular to the axis. In examples where the transverse flow is only in one dimension, such as zig-zag or boustrophedonic flow, the one dimension is perpendicular to the “axial flow.” In examples where the transverse flow is two-dimensional, the fluid motion along two perpendicular axes in a three-dimensional system additionally allows for helical or helicoid flow with rotational motion around the axis and perpendicular to the flow along the axis. Transverse flow may be laminar, but when fluid motion has enough irregularity, diffusivity, vorticity (rotationality) and dissipation to deviate from laminar flow, such flow can be described as turbulent. Here, “transverse flow” along the axis refers to the shape of the flow path defined by the heat exchanger, which may contribute to turbulent flow, but does not refer to incidental or unintentional turbulent flow.

[0025] In one example, the heat exchanger defines non-linear flow of a fluid therethrough, for example wherein a flow path of the fluid defined by the heat exchanger between the inlet and the outlet is non-linear (i.e. the flow path of the fluid from the inlet to the inlet may not be defined by a single straight line). In one example, the flow path of the fluid defined by the heat exchanger between the inlet and the outlet is described by a series of N nodes, wherein N is a natural number greater than or equal to 3 for example 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 or more, including a first node at the inlet, a last or Nth node at the outlet and at least one node therebetween, wherein adjacent nodes are linearly disposed (i.e. line of sight between the adjacent nodes, between surfaces of the heat exchanger) and wherein non-adjacent nodes are non-linearly disposed (i.e. no line of sight between the non-adjacent nodes, due to occlusion by surfaces of the heat exchanger). In one example, the flow of the fluid comprises and / or is turbulent flow. In one example, the flow of the fluid does not comprise and / or is not laminar flow. In one example, the heat exchanger does not comprise an or any unswept volumes.

[0026] In one example, the heat exchanger comprises a wall providing a heat exchanger surface, for example a circumferential heat exchanger surface. For example, a helical circumferential wall provides a helical circumferential heat exchanger surface. In other examples, the heat exchanger comprises an axial core providing an axial heat exchanger surface. For example, a helical axial core providing a helical axial heat exchanger surface. The wall of the heat exchanger defines the space between the inlet and the outlet, and thus defines flow a fluid therethrough.

[0027] The heat exchanger may comprise a metal, an alloy, or another thermally conductive material. In some examples, the heat exchanger consists primarily of aluminum or its alloys. In other examples, the heat exchanger consists primarily of stainless steel or other ferrous alloys.

[0028] In one example, a specific surface area of the heat exchanger changes, for example decreases, axially. “Specific surface area” here means surface area per unit mass or unit volume, e.g., a cross sectional area of flow increases or pitch increases. For the purposes of measuring surface area and volume with relation to the heat exchanger, the volume of the void space is relevant to the vaporization of the fluids, while the volume and mass of the heat exchanger itself is relevant to the thermal capacity of the thermally conducting materials therein. Thus, the relevant “specific surface area” relates to the surface area of the heat exchanger wall against the volume of the void space.

[0029] In one example, the heat exchanger provides a helical heat exchanger surface. “Helical” here means having the general shape of a helix or screw-shape, and may include helicoids, conical spirals, spherical spirals, irregular or regular spirals. The “pitch” relates to the distance between one complete turn of the helix and the next measured parallel to the axis of the helix. The pitch of the helical shape may approach zero in a toroidal void space while still allowing for axial flow of fluids from the inlet to the outlet.

[0030] In one example, the heat exchanger comprises a circumferential wall providing a circumferential heat exchanger surface, for example a helical circumferential wall providing a helical circumferential heat exchanger surface.

[0031] In one example, the heat exchanger comprises an axial core providing an axial heat exchanger surface, for example a helical axial core providing a helical axial heat exchanger surface.

[0032] In one example, the heat exchanger comprises a fin. In one example, the heat exchanger comprises one or more baffles, flow disruptors, and / or structures to direct the flow of fluid or induce turbulent flow of the fluid from the inlet to the outlet. In one example, the fin tapers axially.

[0033] In one example, the heat exchanger is configured to receive a heater therein and / or thereon, for example having a bore (such as an axial bore) to receive a heater therein. In one example, the heater comprises and / or is a commercially available heater cartridge, for example which may be removable and / or replaceable from the heat exchanger. In one example, the heater is connected to and / or controlled by the thermal probe measuring temperature near the outlet. In one example, the heater comprises a smart-controlled heater which dynamically changes energy input based on the outlet temperature of the gas stream. Additional thermocouple positions within the vaporizer, flow control sensors, Coriolis meters, or other sensors may be incorporated to allow for additional measurement and control.

[0034] In one example, the heat exchanger is configured to provide a thermal gradient, for example axially and / or transversely, such as radially. This may be achieved by locating the heater on or in the heat exchanger in a configuration that provides a thermal gradient. In one example, the thermal gradient is radial, such that the heater is located centrally along the axis. In one example, the radial thermal gradient has its highest temperatures along the axial interior (inner core) and lower temperatures along the axial exterior (outer wall). The heater may also be configured to provide other thermal gradients, such as axially or transversely. In one example, the heater comprises an adiabatic heater section to limit excess heat transfer. In one example, the fluid temperature at the inlet is in a range from -273 °C to -50 °C, preferably in a range from -200 °C to -150 °C, most preferably in a range from -165 °C to -160 °C. In one example, the fluid pressure at the inlet is in a range from 0.1 bar to 10 bar, preferably in a range from 0.25 bar to 5 bar, more preferably in a range from 0.5 bar to 2 bar. In one example, the fluid temperature at the outlet is in a range from 0 °C to 200 °C, preferably in a range from 10 °C to 100 °C, more preferably in a range from 20 °C to 60 °C. In one example, the fluid pressure drop between the inlet and the outlet is in a range from 0.01 bar to 1 bar, preferably in a range from 0.025 bar to 0.5 bar, more preferably in a range from 0.05 bar to 0.2 bar. In one example, the fluid temperature at the inlet is in a range from -165 °C to -160 °C, the fluid pressure at the inlet is in a range from 0.5 bar to 2 bar and / or the fluid temperature at the outlet is in a range from 20 °C to 60 °C.

[0035] In one example, the vaporizer comprises insulation enveloping the heat exchanger, for example wherein the inlet and outlet pass through the insulation surface into the heat exchanger. The insulation may be adapted and / or shaped to prevent thermal transfer from the vaporizer to other machinery, materials, or the environment.

[0036] In one example, the insulation includes vacuum insulation. Vacuum insulation means the form of thermal insulation consisting of a gas-tight enclosure which has been evacuated, minimizing conductive thermal transfer from one side of the insulation to the other.

[0037] In one example, the vaporizer comprises vacuum insulation incorporated into the heat exchanger. The insulation vacuums may be shaped to control thermal transfer throughout the vaporizer and from the vaporizer to other machinery, materials, or the environment.

[0038] In one example, the heat exchanger consists primarily of aluminum or its alloys. This includes aluminum alloys suitable for manufacture using additive manufacturing (i.e., three-dimensional printing) including AISi7Mg, AISi Mg, AISi12, and AISi9Cu3.

[0039] In one example, the heat exchanger comprises a material having a thermal conductivity of over 100 watts per meter Kelvin at standard temperature and pressure. The thermal conductivity or specific heat capacity of materials used for the heat exchanger or heat exchanger wall surface may be measured using other known methods or described using other units of measurement.

[0040] In one example, the heat exchanger is adapted for heating a core thereof, for example an axial core thereof.

[0041] In one example, the heat exchanger is adapted for heating a periphery thereof. In one example, the heat exchanger comprises at least one heating surface (also known as a heated surface) and one non-heating surface (also known as a non-heated surface), for example wherein a temperature (for example an average temperature) of the heating surface is at least 100 °C higher than a temperature (for example an average temperature) of the non-heating surface, in use. “Heating surface” here means a portion of the heat exchanger adjacent to the heater which is providing energy in the form of heat to the heat exchanger. “Non-heating surface” here means a portion of the heat exchanger which is not adjacent to the heater and is at least 100 C cooler than the average temperature of the heating surface. In such examples, the heat provided by the heater across the heat exchanger is not uniform, and creates a temperature gradient throughout the void space of the vaporizer. The “nonheating surface” may be colder than the heating surface on account of natural or passive thermodynamic properties of the system, and need not be actively cooled. In one example, the cooling surface comprises and / or is an insulated surface, for example insulated using vacuum insulation.

[0042] In one example, the surface area of the heating surface is less than one-third the surface area of the non-heating surface.

[0043] In one example, the surface area of the heating surface is uniformly curved around the axis, and the non-heating surface is irregularly curved in at least one dimension.

[0044] In one example, the heating surface comprises a cylindrical surface following the axis between the inlet and outlet.

[0045] In one example, the non-heating surface comprises an irregular helix following the axis between the inlet and outlet.

[0046] In one example, the heating surface comprises the radially innermost surface of the heat exchanger, and the non-heating surface comprises the radially outermost surface of the heat exchanger.

[0047] Advantage

[0048] The vaporizers of the present invention have a novel shape and novel vaporization properties which improve the flow patterns of fluids throughout the chamber. By way of example, for the purposes of LNG quality sampling, the improved vaporization properties include decreased pre-fractionation and increased representivity of the sample sent to the gas chromatograph with regards to the quality of the total volume of LNG to be sampled. Here, increased representivity means that the measured composition of the vaporized sample is more representative of the actual composition of the source.

[0049] For example, the shape and / or physical properties of the vaporization chamber controls the vaporization rates of component liquids into component gases. For example, the vaporizer is suitable for vaporizing liquefied natural gas (LNG) into gaseous natural gas, improving the uniformity of vaporization rates and commingling the component liquids into component gasses for more representative measuring of LNG sample quality for analysis in a gas chromatograph, calorimeter or physical sampling device.

[0050] The improved flow and vaporization properties and material properties of the heat exchanger also provide improved insulation and energy transfer. Improved vaporization properties include minimized pressure drop, decreasing pre-fractionation, and a more efficient heat transfer from the heat exchanger to the fluids. Incorporation of vacuum insulation voids also allows for improved thermal transfer throughout the vaporizer heat exchange process whilst reducing heat transfer from the vaporizer to other machinery, materials, or the environment.

[0051] Liquified natural gas

[0052] Liquefied natural gas (LNG) is the liquid form of natural gas, a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane (CH4). Natural gas also contains variable amounts of other larger hydrocarbons such as ethane (C2H6) or propane (C3H8) and other hydrocarbon fractions typically to Hexene, as well as trace gases such as nitrogen, hydrogen sulfide, helium, and carbon dioxide. It can also contain contaminants like mercury, sulfur dioxide, and nitrogen oxides. The variable quality of this mixture affects the burn quality and utility of such natural gas mixtures, and accordingly, their value to natural gas suppliers, transporters, and purchasers.

[0053] Natural gas is liquified for the ease and safety of transport. LNG takes up 1 / 600ththe volume of natural gas in its gaseous state and can be transported at close to 1 ATM, i.e., without significant pressurization. These benefits have led to over 500 billion cubic meters of LNG traded in 2023 with demand increasing year-over-year.

[0054] Before natural gas is converted to LNG through liquefaction, it is often pre-treated to remove impurities such as hydrogen sulfide, carbon dioxide, water, mercury, and larger hydrocarbon molecules (such as heptane or octane). Then it is cooled to between -145 C and -163 C, condensing the gasses into liquid form, i.e., LNG. This cooling process can further remove impurities or contaminants.

[0055] The resultant LNG mixture must be stored in insulated tanks to maintain such low cryogenic temperatures until it is ready to be regassified. Domestic transportation is usually undertaken via truck or trailer designed for cryogenic storage. Internationally, LNG is shipped around the world in seagoing vessels specially constructed for cryogenic storage and transport between a supplier and a receiving terminal.

[0056] LNG quality is one of the most important issues in the LNG industry. Any gas which does not conform to the agreed specifications in the sale and purchase agreement is regarded as “off-specification” (off- spec) or “off-quality” gas or LNG. Quality regulations serve four purposes: 1. To ensure that the gas distributed is non-corrosive and non-toxic, especially with regard to hydrogen sulfide, total sulfur, carbon dioxide, and mercury content;

[0057] 2. To guard against the formation of liquids or hydrates in the networks due to hydrocarbon dewpoints;

[0058] 3. To allow interchangeability of the gases distributed, via limits on the variation range for parameters affecting combustion: content of inert gases, calorific value, Wobbe index, Soot Index, Incomplete Combustion Factor, Yellow Tip Index, etc.; and

[0059] 4. To allow the energy value of such trade to be accurately determined.

[0060] The quality may be measured at the delivery point and points between the delivery point and point of origin. In seeking to vaporize LNG, some heavier components will have a tendency to recondense if the outlet gas stream temperature is not adequately maintained. For example, hexene will condense at atmospheric pressure conditions at around 50 C, therefore it can be understood that the gasified LNG will have different components boiling off at different temperatures and if it is not maintained at a high enough temperature, condensation may re-occur which will bias any sample analysis and thereby compromise the overall valuation of the transaction.

[0061] The quality of the LNG will vary through the transfer of a bulk volume, so small samples must be taken repeatedly during any transfer. These quality measurements are critical in determining whether the LNG meets the criteria for sale and is a predictor of the total value of the LNG being shipped, along with the physical and chemical qualities that determine the “overall energy value” of the LNG when it is regassified and used.

[0062] For this reason, the representivity of these quality measurements is important to both suppliers, transporters, and purchasers of LNG. To meter LNG transfers, typically the volume / mass of the transfer is metered while the total commercial value is based upon the overall energy value (i.e., average energy value (quality) x volume / mass). No technology currently exists to measure the quality of LNG in its cryogenic liquid state, so samples must be vaporized into a gas phase.

[0063] Vaporization Chemistry

[0064] LNG contains a number of mole fractions of different components, the most significant typically being methane. It also may also include components through to Hexene (C6) and other contaminants with no commercial value to the transaction, for example Nitrogen.

[0065] Different chemical components have different physical and chemical properties, including molecular weight, charge, reactivity, electronegativity, stability, and other factors which affect their physical and chemical actions in a mixture. Of special interest here is how these different properties affect volatility or boiling points as these affect vaporization rates, which in turn can affect the accuracy of LNG quality measurements. The primary method of providing an energy value from a sample of LNG that has been gasified is by either:

[0066] • collection of a large volume (typically about 1 m3 - called “dome sampling”) of LNG, which is then subsampled;

[0067] • collection of an intermittent gas sample in a pressurized sample container, which is later analyzed in a laboratory; or

[0068] • gas chromatography.

[0069] These methods are all described in ISO 8943:2007 Refrigerated light hydrocarbon fluids — Sampling of liquefied natural gas — Continuous and intermittent methods.

[0070] A gas chromatograph uses a small slipstream and will analyze a small sample (typically 0.5 - 2 microlitres) about once every 4 minutes. Any methodology that is used to vaporize the sample which potentially may add variation over time in a way that does not accurately mimic the input stream (i.e. temporal variation), has the potential to cause an error in the overall measurement. This may be a systematic bias that would cause one of the trading parties to be subject to a significant gain, the other to a loss.

[0071] Over time it has become evident that commonly used vaporizers have struggled to provide representative flow streams, the primary cause being “pre-fractionation” or bias on the delivery at output of input stream. Often this can be seen as freezing on the vaporizer body and sample lines. As LNG is transported at low temperatures (-160C) very close to its bubble point there is little scope to allow either pressure loss or heat ingress before vaporization. Typically, high levels of insulation are used within LNG systems and existing vaporizers tend to be fabricated in stainless steel.

[0072] Accordingly, complexities in storage, transport, and mixture variability along with known problems with pre-fractionation in LNG samples for quality analysis have led the inventors of the present invention to develop novel designs for vaporizers that control the vaporization rates of component liquids to create more representative flow streams for quality sampling. While the vaporizers here were developed to solve known problems in the LNG industry, the novel methodology of design for these vaporizers can be applied to other industrial or chemical processes involving phase changes, such as liquid to gas vaporization of other substances or mixtures.

[0073] Vaporizing

[0074] The second aspect provides a method of vaporizing a liquid such as liquified natural gas, comprising: vaporizing the liquid using a heat exchanger by flowing fluid thereof therethrough; wherein flowing the fluid includes transversely flowing the fluid in one dimension and / or in two dimensions. Designing

[0075] The third aspect provides a computer-implemented method of designing a heat exchanger for a vaporizer for vaporizing a liquid such as liquified natural gas, comprising: modelling vaporization of the liquid using a heat exchanger comprising simulating flow of a fluid through the heat exchanger and heat exchange therewith; and adapting the heat exchanger based on a result of the modelling.

[0076] In a preferred example, the computer-implemented method of designing a heat exchanger comprises Al-based incorporation of boundary conditions and physical limitations to optimize the vaporization properties of a fluid. Such Al-based incorporation in a human-guided design regimen has been shown to generate heat exchanger shapes which are new and useful to various industrial applications.

[0077] To optimize the use of Al within this area currently requires a strict understanding of the boundary conditions and human input as it iterates to potential solutions. These Al-generated potential solutions must also be conditioned by human input to address the limitations of the manufacturing technologies available and checked for both practicality, conceptual performance, and actual performance.

[0078] In one example of this Al-based design process, such boundary conditions include:

[0079] 1. The heat source, size, containment (of heat source, for safety regulation), energy transfer rates and / or surface temperature limitations. These criteria define the heat input boundaries of the design process.

[0080] 2. The ambient heat (energy) transfer both to the liquid phase (inlet)

[0081] 3. The heat (energy) transfer from the heater cartridge towards the liquid inlet (i.e. before the intended vaporization heat exchange stage)

[0082] 4. The heat (energy) transfer from the heater cartridge and the exterior boundaries of the heat exchanger to ambient.

[0083] Heat so generated may be consumed in the vaporization or the undesired prefractionation at the inlet as well as to the ambient environment. It is therefore required to define a pre- and post- vaporization domain and physical volumes within which the Al program is enabled to propose heat transfer mechanisms recognizing additional process constraints, for example, the minimization of the pressure losses through the heat exchanger mechanism whilst the liquid expands through the three phase regimes: specific heat (liquid), latent heat of vaporization and specific heat of gas. At each point the flow regime is significantly different.

[0084] In addition, starting with human-defined practically derived physical (dimensional) and process input and output boundaries within which to allow the Al program to operate. These include a nominal starting state and ending state for the process. At each iteration, the trained Al generator model proposes geometric design, flow and heat characteristics. The thermal and flow maps generated from such models are reviewed by the engineering group to assure the iterations moved towards a perceived optimal solution (e.g., investigating the effects of the heat transfer on phase change and pressure losses). This also requires close understanding of the heat transfer characteristics from the heater cartridge to the process whilst limiting heat wastage to ambient and within the cold section (pre-vaporization) to ensure that ambient heat ingress was limited. Such investigation and understanding leads to improved parameters and boundary conditions for the Al-based design process, leading to an accelerated improvement of design for vaporizers suited for specific fluids or applications.

[0085] Additive manufacturing model or file

[0086] The fourth aspect provides an additive manufacturing model or file thereof, for example an STL file, of a heat exchanger designed according to the third aspect.

[0087] Method of manufacturing

[0088] The fifth aspect provides a method of manufacturing a heat exchanger designed according to the third aspect, the method comprising: additive manufacturing the heat exchanger, for example using an additive manufacturing model or file thereof according to the fourth aspect.

[0089] Vacuum insulation

[0090] The sixth aspect provides incorporating vacuum insulation to optimize heat transfer in a portion of a heat exchanger for a vaporizer for vaporizing a liquid such as liquified natural gas to improve vaporizer efficiency. Vacuum void spaces or other methods to incorporate vacuum insulation in the heat exchanger may be employed to further control heat transfer through the heat exchanger, or between the vaporizer and the environment, other machinery or equipment. Vacuum insulation is preferably considered in the design process such that the shape of the heat exchanger reflects the thermal properties of the vacuum insulation.

[0091] Providing a heat exchanger

[0092] The seventh aspect provides a method of providing a heat exchanger for a vaporizer for vaporizing a liquid such as liquified natural gas, for example according to the first aspect, the method comprising: designing the heat exchanger, for example according to the third aspect; additive manufacturing the designed heat exchanger, for example according to the fifth aspect; wherein designing the heat exchanger and / or additive manufacturing the heat exchanger comprises incorporating vacuum insulation to optimize heat transfer in a portion of the heat exchanger, for example according to the sixth aspect

[0093] BRIEF DESCRIPTION OF THE DRAWINGS

[0094] For a better understanding of the invention, and to show how exemplary examples of the same may be brought into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which:

[0095] Figures 1 to 22 schematically depict apparatuses according to examples and demonstrate the results of described design methods.

[0096] Figures 23 to 25 schematically depict an apparatus according to an example.

[0097] Figure 26 depicts a vaporization void volume according to an example.

[0098] Figure 27 depicts a spool for mounting a vaporizer according to an example.

[0099] Figure 28 schematically depicts an apparatus according to an example including additional valves in the insulation surface to assist in purging and maintaining the vacuum insulation. It also depicts two cryogenic needle valves on the spool attached to the vaporizer.

[0100] Figures 29 depicts a bi-directional sample probe that is designed to direct couple to an apparatus as depicted in Figure 28.

[0101] Figure 30 depicts an apparatus according to an example within an enclosure with the outlet connected to a flowmeter I metering valve (a vaporizer for any input).

[0102] Figure 31 depicts an apparatus according to an example within an enclosure and connected to the LNG pipeline stub (a vaporizer attached to probe in pipeline).

[0103] DETAILED DESCRIPTION OF THE DRAWINGS

[0104] According to a first embodiment, the vaporizer for vaporizing a liquid such as liquified natural gas comprises: an inlet 101 , an outlet 201 and a heat exchanger 301 , having an axis 302, therebetween; wherein the heat exchanger defines flow of a fluid therethrough; and wherein the flow of the fluid includes transverse flow of the fluid in one dimension and / or in two dimensions. In one example, the vaporizer is for vaporizing liquified natural gas into gaseous natural gas. In other examples, the vaporizer is for vaporizing liquid carbon dioxide into gaseous carbon dioxide. In other examples, the vaporizer is for vaporizing liquids or liquid mixtures into gases or gaseous mixtures.

[0105] The inlet 101 allows fluid to enter the vaporizer. The inlet may incorporate a valve, flow regulator, flow meter, thermometer, sensors, or other devices known in the art to adjust or measure the flow / state of liquids into the vaporizer.

[0106] In some examples, the inlet is designed to function at temperatures in the region close to which the liquid will start to fractionate (-165 C and -140 C and pressures below 5 atm). In other examples, the inlet is designed to function at other temperatures or pressures appropriate to the boiling point of the fluid entering. The inlet may be designed to operate at cryogenic temperatures, and may also be thermally insulated.

[0107] The inlet may be attached to an “in-line” sampler 102 such that the sampler further comprises a a standard tubing connection with liquid drawn from a tank, pipe, existing sample probe or other source.

[0108] The inlet may also draw liquid from a bi-directional sample probe 103 that can be installed directly into a liquid pipeline, such as an LNG pipeline. The bi-directional sample probe may be designed to provide a fresh sample close to the inlet 101 for vaporization and sampling.

[0109] The outlet 201 allows fluid to exit the vaporizer. The outlet may incorporate a valve, flow regulator, flow meter, thermometer, sensors, or other devices known in the art to adjust or measure the flow or state of fluids out from the vaporizer. The outlet may incorporate a thermal probe 202 to measure gas temperature inside the vaporizer near the outlet point. The outlet may also lead directly to a device for analysis of gasses, such as a gas chromatograph, calorimeter or gas sampler.

[0110] In one example, the heat exchanger 301 comprises an interior wall containing the volume for vaporization between the inlet 101 and the outlet 201. The heat exchanger axis 302 may run directly between the inlet and the outlet or may run in a different direction. The shape of the heat exchanger 301 defines the flow of the fluid along the axis 302 and also between the inlet 101 and outlet 201.

[0111] The heat exchanger 301 defines the axial flow of fluid from the inlet 101 to the outlet 201 , but importantly also includes transverse flow of the fluid in at least one dimension. In only one dimension, the transverse flow could be described as zig-zag or boustrophedonic along the axis 302. In two dimensions, the transverse flow could be described as helical or helicoid along the axis 302. In one example, the heat exchanger 301 provides a helical heat exchanger surface. In one example, the helical heat exchanger surface is an irregular helix. In one example, the heat exchanger provides a toroidal void space between its surfaces such that the toroidal radius is perpendicular to the axial flow of fluid from the inlet to the outlet. With regards to the present invention, “axial flow” refers to fluid motion along the axis of a cylindrical or rotational system. It is commonly encountered in scenarios like water flowing through pipes or air flowing through turbines. It is contemplated that vaporizers of the present invention need not be cylindrical or rotational, and could be rectangular, hexagonal, or irregular. The axis 302 also is contemplated to include non-linear axes which would generally define an unobstructed path from the inlet 101 to the outlet 201 through the general shape of the heat exchanger 301. In all such cases, “axial flow” generally refers to flow parallel to the axis 302.

[0112] With regards to the present invention, “transverse flow” refers to fluid motion perpendicular to the axis 302. In examples where the transverse flow is only in one dimension, such as zig-zag or boustrophedonic flow, the one dimension is perpendicular to the “axial flow.” In examples where the transverse flow is two-dimensional, the fluid motion along two perpendicular axes in a three-dimensional system additionally allows for helical or helicoid flow with rotational motion around the axis 302 and perpendicular to the flow along the axis 302.

[0113] In one example, the specific surface area of the heat exchanger 301 changes along the axis 302. In some examples, the specific surface area of the heat exchanger 301 decreases along the axis as fluid flows from the inlet 101 to the outlet 201.

[0114] In one example, the heat exchanger 301 comprises a circumferential wall providing a circumferential heat exchanger surface. For example, a helical circumferential wall providing a helical circumferential heat exchanger surface. In other examples, the heat exchanger 301 comprises an axial core providing an axial heat exchanger surface. For example, a helical axial core providing a helical axial heat exchanger surface.

[0115] In some examples, the heat exchanger 301 may comprise a fin 303. The fin 303 may taper, and may do so axially or in another direction. The fin 303 or fins may further direct the flow of fluid from the inlet 101 to the outlet 201 and may do so in a direction other than the axis 302. The heat exchanger may comprise further baffles, flow disruptors, or structures to direct the flow of fluid. The heat exchanger 301 can introduce turbulent flow along the axis 302, which may increase mixing and decrease prefractionation of various species in a liquid as it is vaporized into a gas. This may also increase the “residence time” of the fluid without leading to pressure losses from separation.

[0116] The heat exchanger 301 may comprise a metal, an alloy, or another thermally conductive material. In some examples, the heat exchanger 301 consists primarily of aluminum or its alloys. In other examples, the heat exchanger 301 consists primarily of stainless steel. In yet other examples, the heat exchanger 301 comprises a material with a thermal conductivity of over 100 watts per meter Kelvin at standard temperature and pressure. The heat exchanger 301 may comprise materials suitable for manufacture using additive manufacturing, i.e., three-dimensional printing. In some examples, the heat exchanger 301 comprises materials suitable for fabrication using additive manufacturing (i.e., three-dimensional printing) techniques. Specifically, aluminum alloys such as AISi7Mg, AISil OMg, AISi12, and AISi9Cu3 are known in the art to be suitable for additive manufacturing and are thermally conductive aluminum alloys. Alternatively, stainless steel alloys such as 17-4 PH, 316L, super Duplex 2507 are known in the art to be suitable for additive manufacturing. Other materials known to be suitable to additive manufacturing include titanium alloys, maraging steel alloys, cobalt chromium alloy, and nickel super alloy. Additive manufacturing techniques that may be suitable for heat exchanger construction include powder-based fusion (PBF), metal binder jetting & sintering (MBJ), direct energy deposition, wire arc additive manufacturing (WAAM), and laser metal deposition (LMD).

[0117] The heat exchanger 301 may be configured to receive a heater 401. The heater 401 may comprise a commercially available heater cartridge, and may be removable and replaceable from the heat exchanger 301. In some examples, the heater 401 is connected to or controlled by the thermal probe 202 measuring temperature near the outlet 201. The heater can comprise a smart-controlled heater cartridge which changes energy input based on the outlet temperature of the gas stream. Additional thermocouple positions within the vaporizer, flow control sensors, Coriolis meters, or other sensors may be incorporated to allow for additional measurement and control.

[0118] In some examples, the heater 401 is located on or in the heat exchanger 301 in a configuration that provides a thermal gradient. In some examples, the thermal gradient is radial, such that the heater 401 is located centrally along the axis 302. In such examples, the radial thermal gradient has its highest temperatures along the axial interior (inner core) and lower temperatures along the axial exterior (outer wall). The heater 401 may also be configured to provide other thermal gradients, such as axially or transversely. In some examples, the heater 401 comprises an adiabatic heater section to limit excess heat transfer.

[0119] In an example, the heat exchanger 301 and heater 401 are configured to provide a gradient wherein at least one heating surface 402 of the heat exchanger 301 adjacent to the heater 401 has an average temperature at least 100 C higher than another surface of the heat exchanger 301. The thermal gradient, along with the physical shape of the heat exchanger, can increase turbulent flow along the axis 302, which may increase mixing and decrease pre-fractionation of various species in a liquid as it is vaporized into a gas. The combination of thermal gradient and physical shape can create expanding and turbulent vaporization space to enable optimal integration of the vaporizing fractions of the components while minimizing pressure losses.

[0120] In some examples, the heating surface 402 comprises a minority of the total surface are of the heat exchanger 301 surface area, such surface areas defined as the interior surface area of the heat exchanger 301 containing the vaporization volume 501 between the inlet 101 and the outlet 201. In similar examples, the heating surface 402 is less than one-quarter (25%) the total heat exchanger 301 surface area.

[0121] In some examples, the heat exchanger 301 surface area is uniformly curved around the axis 302. In other examples, the heat exchanger 301 surface area is irregularly curved in at least one dimension. In yet another example, the heat exchanger 301 surface area comprises an irregular helix following the axis 302 between the inlet 101 and outlet 201.

[0122] In one example, the heat exchanger 301 is enveloped in an insulation surface 601 such that the inlet 101 and outlet 201 can pass through the insulation surface 601 into the heat exchanger 301. In some examples, the insulation surface 601 comprises vacuum insulation or vacuum voids that minimize heat transfer and maximize efficiency.

[0123] Design of Vaporizer

[0124] According to the third aspect, the process of designing a vaporizer suitable for gasifying a liquid such as liquified natural gas is contemplated. Vaporizing liquified natural gas for analysis and use is a commercially important part of the global energy economy, but other industrial and commercial uses for optimized vaporizers exist and can be designed using this new process. For example, the regasification of liquid carbon dioxide may be optimized for sample analysis in the trade of captured carbon (dioxide), or the gasification of an aromatic mixture may be optimized in food preparation. The design processes for the above-described vaporizers suitable for vaporizing liquified natural gas can be reiterated for design of vaporizers which can more effectively gasify liquids and control fractionation and energy input for other fluids in other practical applications.

[0125] First, the vaporization properties of the liquid or liquid mixture are modelled. Specifically, the components of the liquid mixture may have variable: mass, boiling points, volatilities, charge, reactivity, electronegativity, and stability. In some examples, only certain components of the liquid or liquid mixture are modelled, and in others, only vaporization properties are modelled.

[0126] Optionally, the starting temperature and starting flow rate of the liquid mixture, the internal pressure of fluid in the vaporizer, the outflow temperature, rate, and pressure, and the effect of those parameters on the vaporization properties of the liquid are calculated.

[0127] Second, the shape and scale of the design volume that will contain the vaporization void volume 601 , and the location of the inlet 101 and outlet 201 are modeled to set parameters for the vaporizer to be designed. Additionally, the thermal and material properties of the heat exchanger 301 and heater 601 are modeled. Optionally, the thermal properties and / or location of the heating surface 402 and / or heater 401 are modelled. NOTES

[0128] Although a preferred embodiment has been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims and as described above.

[0129] At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as ‘component’, ‘module’ or ‘unit’ used herein may include, but are not limited to, a hardware device, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term “comprising” or “comprises” means including the components) specified but not to the exclusion of the presence of others.

[0130] Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

[0131] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive.

[0132] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[0133] TABLE OF REFERENCE NUMERALS

Claims

AMENDED CLAIMS received by the International Bureau on 12 December 2025 (12.12.2025)1 . A vaporizer for vaporizing a liquid such as liquified natural gas, comprising: an inlet, an outlet and a heat exchanger, having an axis, therebetween; wherein the heat exchanger defines flow of a fluid therethrough; and wherein the flow of the fluid includes transverse flow of the fluid in one dimension and / or in two dimensions, wherein a specific surface area of the heat exchanger changes, for example decreases, axially.

2. The vaporizer according to any previous claim, wherein the heat exchanger provides a helical heat exchanger surface.

3. The vaporizer according to any previous claim, wherein the heat exchanger comprises a circumferential wall providing a circumferential heat exchanger surface, for example a helical circumferential wall providing a helical circumferential heat exchanger surface.

4. The vaporizer according to any previous claim, wherein the heat exchanger comprises an axial core providing an axial heat exchanger surface, for example a helical axial core providing a helical axial heat exchanger surface.

5. The vaporizer according to any previous claim, wherein the heat exchanger comprises a fin.

6. The vaporizer according to any previous claim, wherein the fin tapers axially.

7. The vaporizer according to any previous claim, wherein the heat exchanger is configured to receive a heater therein and / or thereon.

8. The vaporizer according to any previous claim, wherein the heat exchanger is configured to provide a thermal gradient, for example axially and / or transversely, such as radially.

9. The vaporizer according to any previous claim, wherein the fluid temperature at the inlet is between -165 C and -160 C with an absolute pressure of 0.5 to 2 bar and the fluid temperature at the outlet is between 20 C and 60 C.

10. The vaporizer according to any previous claim, comprising an insulation surface enveloping the heat exchanger, wherein the inlet and outlet pass through the insulation surface into the heat exchanger.

11. The vaporizer of claim 10, wherein the insulation surface includes vacuum insulation.

12. The vaporizer according to any previous claim, wherein the heat exchanger consists primarily of aluminum or its alloys.

13. The vaporizer according to any previous claim, wherein the heat exchanger comprises a material with a thermal conductivity of over 100 watts per meter Kelvin at standard temperature and pressure.

14. The vaporizer according to any previous claim, wherein the heat exchanger comprises at least one heating surface and one non-heating surface, such that the average temperature of the heating surface is at least 100 C higher than the average temperature of the non-heating surface.

15. The vaporizer according to claim 14, wherein the surface area of the heating surface is less than one-third the surface area of the non-heating surface.

16. The vaporizer according to claim 14, wherein the surface area of the heating surface is uniformly curved around the axis, and the non-heating surface is irregularly curved in at least one dimension.

17. The vaporizer according to any of claims 14 to 16, wherein the heating surface comprises a cylindrical surface following the axis between the inlet and outlet.

18. The vaporizer according to any of claims 14 to 17, wherein the non-heating surface comprises an irregular helix following the axis between the inlet and outlet.

19. The vaporizer according to any of claims 14 to 18, wherein the heating surface comprises the radially innermost surface of the heat exchanger, and the non-heating surface comprises the radially outermost surface of the heat exchanger.20, A method of manufacturing a vaporizer according to any of claims 1 to 19, comprising using additive manufacturing or three-dimensional printing to construct the heat exchanger.

21. A method of designing a vaporizer according to any of claims 1 to 19, comprising modelling vaporization of the liquid using a heat exchanger comprising simulating flow of a fluid through the heat exchanger and heat exchange therewith; and adapting the heat exchanger based on a result of the modelling.

22. A heat exchanger suitable for use in a vaporizer according to any of claims 1 to 19.

23. A method of manufacturing a heat exchanger according to claim 22. comprising using additive manufacturing or three-dimensional printing to construct the heat exchanger.

24. A method of designing a heat exchanger according to claim 22. modelling vaporization of the liquid using a heat exchanger comprising simulating flow of a fluid through the heat exchanger and heat exchange therewith; and adapting the heat exchanger based on a result of the modelling.

25. A heat exchanger of claim 22 which further comprises vacuum insulation.

26. A method of designing a heat exchanger of claim 23 further comprising vacuum insulation voids formed through additive manufacturing.

27. A vaporizer of any of claims 1 to 19 further comprising vacuum insulation incorporated into the heat exchanger.

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