• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A double-walled vacuum-insulated container (30, 40) has an outer wall (1), an inner wall (3) and, in between, a vacuum chamber (5) in which a heat-insulating device (2, 20) is arranged. At least three spaced-apart temperature sensors (13, 13a, 13b, 14, 15) detect recurring current temperatures (T1, T2, T2A, T2B, T3) of the container (30, 40). At least pointwise, a temperature profile is calculated using a heat transfer model based on the design and material properties of the container and the resulting thermal radiation, which temperature profile includes at least two of the sensed temperatures (T1, T2, T2A, T2B, T3). From the temperature profile, a temperature setpoint for the position of at least one other of the temperature sensors is calculated and compared with the actual temperature value detected by this temperature sensor. From the deviation between the temperature setpoint and the actual temperature value, a change in the thermal insulation quality of the container is detected.
    公开号:AT519232A4
    申请号:T50028/2017
    申请日:2017-01-16
    公开日:2018-05-15
    发明作者:Ing Dr Matthias Rebernik Dipl
    申请人:Cryoshelter Gmbh；
    IPC主号:
    专利说明:

    Device and method for determining the thermal insulation quality of double-walled vacuum-insulated containers
    The invention relates to a device and a method for determining the thermal insulation quality of double-walled vacuum-insulated containers.
    The insulation quality of double-walled, vacuum-insulated containers depends on the one hand on the vacuum quality. The vacuum pressure gradually increases over time - over the course of months or years - by outgassing the materials and surfaces involved and / or by diffusion through the sealing walls. As a result of mechanical defects such as Cracks or severe damage, the vacuum pressure can also increase very quickly. If the vacuum pressure rises above a certain threshold value, this leads to an increased heat input via the vacuum insulation and thus to an impairment of the insulation quality. The insulation quality can be restored by pumping the vacuum chamber empty again. However, emptying is complex and time-consuming.
    On the other hand, the insulation quality depends on the undisturbed structure of the super insulation. The simplest example is a single heat insulation shield, the primary task of which is to prevent heat radiation, which is why the term heat radiation shield is also used for this. In the following description, the abbreviated term “shield” is sometimes used instead of the terms “heat insulation shield” or “heat radiation shield”; all three terms, as used herein, have the same meaning. The heat radiation shield is attached between the inner wall (inner tank) and outer wall (outer container) in such a way that there is no direct contact between the heat radiation shield and the outer container or between the heat radiation shield and the inner tank apart from the shield suspension. Such direct contact would impair the insulation quality - depending on the contact surface - as a consequence of the additional direct heat conduction between the heat radiation shield and the respective wall. The same applies to multi-layer insulation (MLI multi-layer insulation), which is made up of a number of aluminum foils and fiber mats (or similar materials with a low thermal conductivity) placed in between. The effective insulation quality depends, among other things, on depends essentially on the layer density, i.e. the force with which the individual layers are pressed against each other. This force influences the heat conduction between the layers and thus the total heat flow in the direction of the cold inner wall compared to the outer wall. Is this force - even locally - due to deformation e.g. of the outer container increases, the heat input increases.
    / 27
    The problem on which the invention is based is explained below using the example of cryogenic containers. Cryogenic containers are used to store and transport cryogenic liquefied gases at temperatures of -120 ° C and colder. Cryogenic containers are made up of an outer container and an inner tank. The inner tank is attached to the outer tank by an inner tank suspension. Pipelines for filling and withdrawing the liquefied gas lead from the inner tank through the vacuum insulation room to the outer container. The outer container and inner tank do not touch each other. The space (vacuum chamber) between the outer container and the inner tank is evacuated. In addition, thermal insulation is installed in the vacuum chamber, which comprises one or more heat radiation shields which reduce the heat input caused by heat radiation. The optimal insulation effect of the heat radiation shields is achieved when the vacuum pressure is less than 10 -4 mbar, since from this pressure the heat transfer through the remaining free molecules (residual gas) is negligible. If the pressure rises above this value, the heat transfer through the residual gas increases, up to the formation of free convection and the associated considerable heat input, which can increase the storage losses of cryogenic containers until they are unusable.
    In order to measure vacuum pressures in the order of magnitude of around 10 -4 mbar, sensitive and expensive sensors and evaluation units such as Pirani vacuum gauges are required, which can be used down to minimum pressures of 10 -4 mbar, or ionization vacuum gauges which are used to determine pressure in high and ultra-high vacuum range, that is from about 10 -3 to 10 -12 mbar. The principle of ionization vacuum gauges is based on an indirect pressure measurement using electrical variables that are proportional to the residual gas particles with the particle number density. For this purpose, the residual gas must be ionized, for which there are different implementation options: cold cathode ionization vacuum meters and hot cathode ionization vacuum meters.
    However, these measurement methods are expensive and in particular are not suitable for use in mobile applications, such as, for example, liquid gas tanks, in particular liquid natural gas (LNG) fuel tanks.
    The present invention uses the temperature profile (several temperatures) at selected measuring points of the double-walled container and / or in the double-walled container (e.g. measuring points on thermal insulation layers of a multi-layer insulation, on heat radiation shields, on the inner wall and / or on the outer wall) as a measurement variable / 27 for the detection of a Changing the heat flows via the vacuum insulation of double-walled vacuum-insulated containers. The change in the heat flow (usually an increase) can result from:
    - an additional and / or increased physical contact (due to increased contact pressure) between one of the containers and a heat radiation shield or one or more layers of multilayer insulation;
    - a change in vacuum pressure; and or
    a change in the thermal radiation properties of the acting surfaces, e.g. through wear and tear (over the lifetime).
    JP 2006-078190 A describes a system in which a temperature sensor that does not touch either wall is arranged in a vacuum chamber formed between an outer wall and an inner wall. The temperature sensor can be wrapped in a multilayer thermal insulation film. This system is used in such a way that the temperatures of the outer wall and the inner wall are first measured with the vacuum of the vacuum chamber intact or can be assumed to be fixed, e.g. Room temperature on the outer wall and -196 ° C (= boiling point of nitrogen) on the inner wall, which forms a nitrogen container, and at the same time the temperature sensor measures the temperature in the vacuum chamber, which is set as the reference temperature. During operation, further temperature measurements are carried out with the temperature sensor, the outside and inside wall temperature having to remain constant, a vacuum loss (pressure rise) in the vacuum container being determined by comparing the reference temperature with the temperature currently measured by the temperature sensor. The description of this document shows that an increase in the temperature in the vacuum container is interpreted as an increase in pressure. Optionally, a device for detecting the occurrence of an abnormality in the thermal load is additionally provided in the known system, this detection device not being the temperature sensor. Instead, the detection device can be a temperature constant device, on which it is detected whether it suddenly needs to apply more energy than normal to keep the temperature of the interior formed by the inner wall constant. As an alternative embodiment of such a detection device, the detection of the amount of evaporated nitrogen from a nitrogen container arranged in the interior with liquid nitrogen is mentioned. An increase in the amount of vaporization is interpreted as an abnormality. With this detection device, the occurrence of problems with a / 27
    Superconductor cable cooling system or a device arranged in the nitrogen tank can be monitored. External abnormalities are obviously not considered. This monitoring system is therefore only suitable for restricted applications in which it can be assumed that the outside temperature does not change and that no disturbances caused by outside occur. The disclosed restricted applications include a liquid nitrogen container that houses laboratory equipment or superconducting cable cooling systems that are stationary in rooms. However, the known monitoring system is unsuitable for applications in which the outside temperature can vary or, more generally, the environmental parameters are variable. Such variable environmental parameters are particularly prevalent in vehicles which are exposed to changing temperatures, changing weather conditions and dynamic mechanical loads. In particular, the known system for monitoring liquid gas tanks on vehicles is completely unsuitable.
    The present invention overcomes the limitations and disadvantages of the prior art by providing an apparatus and a method for determining the thermal insulation quality of a double-walled vacuum-insulated container with the features of claims 1 and 13, respectively.
    Further advantages and features of the invention emerge from the subclaims and the following description of exemplary embodiments.
    The device according to the invention serves to determine the thermal insulation quality of a double-walled vacuum-insulated container, the container having an outer wall facing the surroundings and an inner wall defining an inner tank, a vacuum chamber being formed in the at least one heat-insulating device between the outer wall and the inner wall of the double-walled container is. At least three spaced-apart temperature sensors are arranged on or in the container, which recurrently record current temperatures of the container, the positions of the temperature sensors being selected from positions on the outer wall, the inner wall and / or the heat insulation device. An evaluation unit equipped with a computing unit and a storage unit receives the temperatures detected by the temperature sensors. A heat transfer model, preferably in layers, is stored in the evaluation unit on the basis of the construction and material properties of the container and the heat radiation resulting therefrom. The evaluation unit is designed to use the heat transfer model / 27 to calculate, at least point by point, a temperature profile that contains at least two of the temperatures detected by the temperature sensors, and to use the temperature profile to calculate a temperature setpoint for the position of at least one other of the temperature sensors, and with that to actually compare the actual temperature value detected by this temperature sensor and to detect a change in the thermal insulation quality of the container from the deviation between the temperature setpoint value and the actual temperature value if the deviation lies beyond a limit value. The heat transfer model of the container preferably also takes into account the heat conduction resulting from the construction and material properties of the container.
    The heat transfer model can be calculated using the equations given in the following description. The design of the container, i.e. The materials of the container, their properties, the connection points and the geometry of the container are already known and enable the heat transfer model to be created in advance, which is stored in the evaluation unit memory after it has been created. Alternatively, but not preferred due to the high computational complexity, the design data of the container could also be stored in the evaluation unit and the evaluation unit itself could use this design data to calculate the heat transfer model. The heat transfer model is preferably a layer model.
    Heat radiation is proportional to the fourth power of the temperature (T 4 ), whereas the solid-state heat pipe and the residual gas heat pipe are essentially proportional to the first power of the temperature (T 1 ).
    The temperature profiles / the temperatures differ correspondingly clearly with different compositions of the proportions of the individual types of heat transfer, and this effect is used to determine the thermal insulation quality of a double-walled vacuum-insulated container according to the invention.
    The invention will now be explained in more detail using exemplary embodiments with reference to the drawings.
    Fig. 1 shows a cryogenic container with a device according to the invention for determining the thermal insulation quality of this double-walled vacuum-insulated container schematically in longitudinal section.
    / 27
    FIGS. 2 to 5 show temperature-path diagrams which illustrate the influence of the temperatures prevailing on the outer wall and the inner wall of the cryocontainer on the temperature of a heat insulation shield with an intact vacuum.
    6 shows a temperature-path diagram with a constant outside temperature on the outside wall and a constant inside tank temperature on the inside wall of the cryocontainer, with vacuum pressure degradation in the vacuum chamber.
    FIG. 7 shows a further embodiment of a cryocontainer with a device according to the invention for determining the thermal insulation quality of this double-walled vacuum-insulated container schematically in cross section.
    Fig. 1 shows a cryocontainer 30 according to the invention schematically in longitudinal section. The cryocontainer 30 is designed as a double-walled container, with an outer wall 1 which defines an outer container and an inner tank which is arranged in the outer container and is defined by an inner wall 3. The space between the outer wall and the inner wall forms a vacuum chamber 5 which is evacuated before the cryocontainer 30 is started up. The inner tank is designed to hold liquefied gas 6 and for this purpose has a pipeline 8 leading from the interior 7 of the inner tank through the vacuum chamber 5 and the outer wall 1. The fill level 16 of the liquefied gas 6 can be measured with a fill level meter 17, the signal of which is fed to an evaluation unit 18 explained in more detail below. The inner tank is fastened in the outer container by means of a suspension which comprises a first rod 10 rigidly connecting the outer wall 1 and the inner wall 3, preferably made of poorly heat-conducting material, and a second rod 11 arranged opposite the first rod 10 and fixed to the inner wall 3 is mounted and axially displaceably mounted in a slide bearing 12 which is attached to the outer wall 1. The outer wall 1 and the inner wall 3 of the cryocontainer 30 have no direct contact with one another due to this suspension. The inner wall 3 is surrounded by at least one heat insulation shield 2 arranged in the vacuum chamber 5, the at least one heat insulation shield 2 being suspended from the outer wall 1 by means of fastening rods 9 made of poorly heat-conducting material. As an alternative to the fastening rods 9, the at least one heat insulation shield 2 can also be fastened adiabatically to the rods 10, 11. A temperature sensor 13 is attached to the heat insulation shield 2, which measures the temperature T 2 of the heat insulation shield 2 repeatedly. At least two further temperature sensors 15, 14 repeatedly measure the temperature T 1 of the outer wall 1 (by means of temperature sensor 15) and / or the temperature T 3 on the inner wall 3 (by means of temperature sensor 14) and / or the temperature on at least one further heat insulation shield (in this Figure not shown). Alternative to one or more / 27
    Thermal insulation shields 2 can be provided with a multi-layer insulation (MLI) (see Fig. 7) which comprises several composite layers made of a metal foil, e.g. Aluminum foil, and a heat insulating material, e.g. Fiber material or foam. The composite layers can be arranged, preferably concentrically, around the inner wall, or can be designed as a winding with several turns. In such an embodiment, a temperature sensor is arranged on at least one composite layer of the multilayer insulation. The temperature signals of the temperature sensors 13, 14, 15 are fed to an evaluation unit 18 which - if present - also receives the signals from the level meter 17. In addition or as an alternative to a temperature sensor 14 on the inner wall 3, a pressure sensor 19 can be provided in the interior 7, the pressure signals of which are fed to the evaluation unit 18. The temperature of the liquid gas 6 in the interior can be calculated from the pressure values in the interior 7, as explained in detail below, and the temperature of the interior wall 3 can be derived therefrom. Instead of the temperature sensor 15 on the outer wall 1, the temperature of an ambient thermometer (e.g. vehicle outer thermometer) can be approximately assumed as the temperature of the outer wall 1. Such ambient thermometers are now standard on vehicles. However, it should be noted that the accuracy of the inventive method is reduced. The signals from the temperature sensors 13, 14, 15, the fill level meter 17 and the pressure sensor 19 can be transmitted to the evaluation unit 18 in a wireless or wired manner. In the case of wireline, the wires can e.g. take place along the rod 10, the fastening rods 9 or the tube 8, or a dedicated cable guide can be formed in the cryocontainer 30.
    The temperature of the heat insulation shields or the multi-layer insulation depends on:
    - The emissivities of the surfaces: namely the inside of the outer wall, the respective sign (outside and inside) and the outside of the inside wall;
    - the number and size of the openings or other openings (faults) in the shields;
    - Solid-state heat conduction via design-related thermal bridges to / from the shields to neighboring components, e.g. the inner wall, the outer wall, piping, etc .;
    - Solid-state heat conduction via (unforeseen, e.g. caused by mechanical action) thermal bridges to / from the shields to neighboring components;
    - the residual gas heat pipe, which depends on the vacuum pressure.
    / 27
    The evaluation unit 18 of the device 30 according to the invention is designed to calculate a temperature profile based on heat transfer by thermal radiation, which contains the at least two temperatures, and this temperature profile from at least two temperature signals supplied by the at least three spaced-apart temperature sensors 13, 14, 15 to be related to at least the third determined temperature and thereby to deduce the vacuum pressure in the vacuum chamber 5 or to detect any damage to the outer wall 1 and / or the inner wall 3. Heat radiation is proportional to the fourth power of the temperature (T 4 ), whereas the solid-state heat pipe and the residual gas heat pipe are proportional to the first power of the temperature (T 1 ). Accordingly, the temperature profiles based on the heat radiation differ significantly from temperature profiles based on solid-state heat conduction and / or residual gas heat conduction. Temperature profiles based on thermal radiation have a curved profile, whereas temperature profiles based on solid-state heat conduction and residual gas heat conduction essentially follow a straight line.
    The temperature measured repeatedly on the outer wall 1, a heat insulation shield 2 and the inner wall 3 of the cryocontainer 30 explains how the heat input into the inner tank defined by the inner wall 3 is determined according to the invention and thus the vacuum pressure in the vacuum chamber 5 is determined or if necessary, damage to the outer wall 1 and / or the inner wall 3 can be detected. For a better understanding, reference is made to the temperature profiles shown in the temperature / path diagrams of FIGS. 2 to 5, which each show the measured temperatures on the outer wall 1, the heat insulation shield 2 and the inner wall 3. It should be mentioned that the measuring and evaluation principles according to the invention explained below are also valid if one of the temperatures is measured on a further heat insulation shield instead of on the outer wall 1 or the inner wall 3. It is also possible and recommended with regard to the accuracy of the evaluation to use more than three temperatures for the measurement.
    The diagrams in FIGS. 2 to 5 show the influence of the temperatures prevailing on the outer wall 1 and the inner wall 3 on the temperature of the heat insulation shield 2 when the vacuum in the vacuum chamber 5 is intact. FIG. 2 shows temperature profiles with constant outside temperature and varied inside tank temperatures. Fig. 3 shows temperature profiles with a constant internal tank temperature and varied outside temperatures. 4 shows temperature profiles with a combination of the highest outside temperature with the highest inside tank temperature and vice versa. 5 shows temperature profiles at a / 27
    Combination of the highest outside temperature with the lowest inside tank temperature and vice versa.
    The outside temperature in the automotive application of the double-walled, vacuum-insulated cryogenic container or cryogenic tank is usually expected (designed) between -40 ° C (243K) and + 65 ° C (338K); the high temperature is reached in direct sunlight on the cryocontainer. The internal tank temperature is determined by the storage pressure, because cryogenic liquids are stored as boiling liquids and the boiling temperature is dependent on the pressure, see Table 1 below.
    Liquid methane print boiling [bar] [K] [° C] 0.0 112 -162 8.0 147 -126 16.0 162 -111
    Table 1: Boiling temperature of methane depending on the pressure
    Since the storage pressure in the cryogenic tank (cryogenic tank) can vary greatly depending on the operating mode - open tank, closed tank - a corresponding change in the internal tank temperature can be expected. In real operation, the actual internal tank temperature, depending on the tank size, can deviate a few Kelvin from the theoretical boiling temperature due to deviations from the ideal thermodynamic equilibrium state. However, this does not significantly reduce the meaningfulness of the evaluation.
    6 shows a temperature-path diagram with a constant outside temperature on the outside wall 1 and a constant inside tank temperature on the inside wall 3, with vacuum pressure degradation in the vacuum chamber, represented by a factor that is proportional to the heat transfer through residual gas heat conduction (RGL). An RGL factor of 0.4 (measuring points shown as squares □) represents an intact vacuum in the vacuum chamber 5, in which the heat transfer by residual gas heat conduction is negligible. An RGL factor of 3.6 (measuring points shown as circles o) represents an impaired vacuum in the vacuum chamber 5, and an RGL factor of 15 (measuring points shown as triangles ▲) represents a significantly impaired vacuum.
    / 27
    Fig. 6 shows the influence of increasing heat transfer (in addition to the existing heat transfer by radiation) through residual gas heat conduction (even if the transfer regime changes up to convection). The shield temperature drops (!) With a degraded vacuum of 248 K with an RGL factor of 0.4 to 220 K with an RGL factor of 15. In constant ambient conditions, a change in the vacuum pressure can be read from the shield temperature with good signal quality. Contrary to the intuitive expectation and the views of the experts in the published state of the art, however, the shield temperature does not rise when the vacuum quality deteriorates, but rather decreases (!). The reason lies in the different proportionality of the different types of heat transfer to the temperature (difference). The shield temperature is set at a temperature where the heat flow Q 12 from the outer wall 1 to the shield 2 is equal to the heat flow Q 23 from the shield 2 to the inner wall 3, this requires continuity. Pure heat radiation follows the difference between the fourth powers of temperature, while residual gas heat conduction or heat conduction follows the difference of temperature (first power, linear). If heat radiation is clearly dominant, it follows that the temperature difference between outer wall 1 and shield 2 is significantly lower than between shield 2 and inner tank 3.
    If a linear component is added (residual gas heat conduction, heat conduction), the shield temperature drops in extreme cases towards the arithmetic mean of the outside temperature and the inside tank temperature.
    An increase in the shield temperature is only possible if there is an additional heat flow from the outer wall to the shield, e.g. if there is such a physical contact due to a dent in the outer wall. Continuity requires that the additional heat is transferred from the outside to the inner tank, whereby there is no change in the composition of radiation and possibly other heat flows (such as existing sign hangers or the like). Therefore, the temperature difference must increase, i.e. the shield temperature. (The internal tank temperature is determined by the pressure-dependent boiling point of the stored gas).
    Due to the wide range within which the temperatures of the outer wall and the inner tank can move, it is not possible to detect a deterioration in the vacuum or the insulation quality based on the shield temperature alone. An interpretation of the measured temperatures is only possible with the help of a calculation or approximation that takes into account the responsible types of heat transfer.
    / 27
    Based on the knowledge described above and the knowledge of the relationships, it is now possible to detect different types of damage or to carry out additional plausibility checks.
    The evaluation of the measured temperatures also enables conclusions to be drawn about the vacuum pressure. The shield temperature as a function of the vacuum pressure is known from measurements at different vacuum pressures. At the same time, the shield temperature can be calculated at different vacuum pressures using the theoretical description of the physical and thermodynamic relationships. By comparing the measurements and calculations, the necessary parameters can be determined again with better precision than is possibly only possible based on literature values. This means that - assuming the positive assessment of all plausibility checks - the vacuum pressure can be inferred based on the shield temperature. The explanations above are expressed below using physical formulas:
    Outer wall 1 Q 12 shield 2 Q 23 inner wall 3
    Q12 Q radiation12 + Q heat pipe12 + Q residual gas heat pipe12 Q 23 Q radiation23 + Q heat pipe23 + Q residual gas heat pipe23
    Q12 "Q23
    Q radiation 12 = f (T1 / T 2 4 , 81, 82, A1, A 2 , σ)
    Q heat conduction12 = f (T /, T2 1 , λχ 2 , L12, A12) ... (Fourier law) Q residual gas heat conduction proportional to f (p RGL, T , · • ) (the above equations apply analogously to Q 23 _ Q radiation23 + Q heat conduction23 + Q residual gas heat conduction23 ) where:
    Q ... heat flow (Q 12 from the outer wall to the shield, Q 23 from the shield to the inner wall) / 27
    T ... temperature (T 1 on the outer wall 1, T 2 on the shield, T 3 on the inner wall) ε ... emissivity (ε 1 on the outer wall 1, ε 2 on the shield 2) σ ... Boltzmann constant
    A ... area (A 1 of the outer wall, A 2 of the shield 2) λ 12 ... thermal conductivity of the suspension
    L 12 ... 1 / length of the suspension relevant to heat conduction
    Prgl ... vacuum pressure
    This system of equations can be solved depending on the temperature or the vacuum pressure. It should be pointed out that at vacuum pressures of approx. 10 -4 mbar and less, the proportion of the heat transferred through residual gas heat conduction is negligibly low, ie that the thermal insulation system has achieved its desired performance. It also means that the shield temperature T 2 no longer changes at vacuum pressures equal to or less than this threshold value. However, as soon as the vacuum pressure rises to such an extent that a heat flow that is technically relevant due to residual gas heat conduction occurs, this can be recognized by the falling (!) Shield temperature. The shield temperature is proportional to the vacuum pressure in the relevant area. It is therefore possible to draw conclusions about the vacuum pressure in this area via the shield temperature.
    The evaluation is equally possible when using multiple shields or multi-layer insulation (MLI) or combinations of shield and multi-layer insulation. Three measured temperatures are usually sufficient. off, whereby the outer container temperature is not absolutely necessary for this. For example, it is sufficient to measure the temperature of two shields and the inner tank, since the composition of the heat flows and the continuity equation can be used to draw sufficient conclusions about the compliance with reasonable limit values. As long as heat radiation dominates as a transmission mechanism - as is the case with properly functioning vacuum insulation - the measured temperatures will be found on a characteristic curve (even if there is no continuous temperature curve in the vacuum, but rather discrete points on the vacuum and thus " temperature-free “surrounding structures). Due to this temperature profile in a vacuum consisting of discrete temperature points, it is a permissible approximation to compute the characteristic temperature curve from straight line segments, each of which connects the temperatures of adjacent discrete temperature points, whereby it can be determined from the angle α between adjacent straight line segments whether the prevailing heat transfer does not Heat radiation with a temperature curve to the fourth power and thus the vacuum pressure is sufficiently low, or whether linear / 27
    Heat conduction mechanisms play an undesirably high role, which indicates defects in the cryogenic container. From the speed of the change in the angle α, the speed of the change in temperature at this discrete point is proportional, from which the reason for the change can be deduced.
    The evaluation using the system of equations above can also take into account permanently installed heat conduction paths, i.e. e.g. the heat conduction that flows into the shields via the shield's suspension system. Thus, heat conduction or the "finished construction" can be included in the target assessment. At the same time, this in turn gives the opportunity to determine a deviation. E.g. increases the shield temperature, this can only be caused by an additional (unforeseen) heat flow from the outer wall to the shield. An increase in vacuum pressure, on the other hand, would affect the heat flows on both sides (inside and outside) at the same time.
    This device is therefore also suitable, optionally in combination with plausibility checks listed below, with the aid of further parameters to detect critical mechanical damage to the cryogenic tank or mechanical structures of the insulation system.
    Instead of measuring the internal tank temperature, the internal tank pressure can be measured and evaluated: As described, the boiling temperature of gases (substances) stored in it changes depending on the storage pressure in the internal tank. With cryogenic tanks, deviations from the thermodynamic equilibrium state occur depending on the size of the tanks (from a few liters to thousands of cubic meters in general), i.e. that the liquid phase can be "supercooled", i.e. the temperature determined on the basis of the measured pressure is a few Kelvin above the actual temperature.
    During the refueling process, pressure is generated by a pump, so pressure and temperature are decoupled from one another in this transient state. By e.g. Such a process can be recognized and correctly interpreted by integrating the level signal into the evaluation of the wall temperatures and sign temperatures.
    During removal (possibly also filling) - due to unintentional or constructive contact between the pipes and insulation / shields - the shield temperature can deviate significantly from the temperature to be expected in the idle state. By recognizing / 27 the corresponding state, the wall temperatures and sign temperatures can still be interpreted correctly.
    Due to the speed of the change in the measured temperatures, damage cases can be distinguished from intact functionality. A vacuum break e.g. leads to a very rapid change in temperature compared to the change in temperature when the pressure in the container rises slowly, e.g. parked vehicle in changing environmental / weather conditions. A comparison of the rates of change of the respective conditions therefore also serves to correctly interpret the wall temperatures and the shield temperature.
    7 schematically shows a second embodiment of a cryocontainer 40 according to the invention in cross section. Like the embodiment shown in FIG. 1, the embodiment of the cryocontainer 40 is also constructed as a double-walled container, with an outer wall 1 which defines an outer container and an inner tank arranged in the outer container and defined by an inner wall 3. The space between the outer wall and the inner wall forms a vacuum chamber 5, which is evacuated before the cryocontainer 40 is started up. The inner tank is designed to hold liquefied gas 6. The fill level 16 of the liquefied gas 6 can be measured with a fill level meter 17, the signal of which is fed to the evaluation unit 18. The suspension of the inner tank on the outer container is omitted for reasons of clarity, but it corresponds to that of the first embodiment. The inner wall 3 is surrounded by a thermal insulation device in the form of a multi-layer insulation (MLI) 20, which several composite layers 21 made of a metal foil 22, e.g. Aluminum foil, and a heat insulating material 23, e.g. Fiber material or foam. The composite layers 21 are arranged concentrically around the inner wall 3. Alternatively, the composite layers 21 can be designed as a winding with a plurality of turns. The multi-layer insulation 20 can be suspended like the shields in the first embodiment.
    In this embodiment, temperature sensors 13 a, 13 b (number of temperature sensors is not limited to two) are arranged on a plurality of composite layers 21, which repeatedly measure the temperatures T 2A , T 2B at spaced apart points of the multilayer insulation 20. Two further temperature sensors 15, 14 repeatedly measure the temperature T 1 of the outer wall 1 (by means of temperature sensor 15) and / or the temperature T 3 on the inner wall 3 (by means of temperature sensor 14). The temperature signals of the temperature sensors 13a, 13b, 14, 15 are fed to the evaluation unit 18/27, which also receives the level signals f of the level meter 17. In addition or as an alternative to the temperature sensor 14 on the inner wall 3, a pressure sensor 19 can be provided in the interior 7, the pressure signals of which are fed to the evaluation unit 18. Instead of the temperature sensor 15 on the outer wall 1, the temperature of an ambient thermometer (for example a vehicle outer thermometer) can be approximately assumed as the temperature of the outer wall 1. The temperature signals, pressure signals and signals from the level meter are evaluated as described above.
    权利要求:
    Claims (22)
    [1]
    claims:
    1. Device for determining the thermal insulation quality of a double-walled vacuum-insulated container (30, 40), the container having an outer wall (1) facing the surroundings and an inner wall (3) defining an inner tank, one between the outer wall and the inner wall of the double-walled container Vacuum chamber (5) is formed, in which at least one heat insulation device (2, 20) is arranged, characterized in that the container (30, 40) has at least three spaced-apart temperature sensors (13, 13a, 13b, 14, 15) which recurrently record current temperatures of the container (30, 40), the positions of the temperature sensors (13, 13a, 13b, 14, 15) being selected from positions on the outer wall (1), the inner wall (3) and / or the heat insulation device ( 2, 20), the device comprising an evaluation unit (18) which detects the temperatures (T 1 , T 2 , T. 2 ) detected by the temperature sensors (13, 13a, 13b, 14, 15) 2A , T 2B , T 3 ), wherein a, preferably layer-by-layer, heat transfer model is stored in the evaluation unit (18) on the basis of the construction and material properties of the container and the resulting heat radiation, and the evaluation unit (18) is designed for this is to use the heat transfer model to calculate, at least point by point, a temperature profile which contains at least two of the temperatures (T 1 , T 2 , T 2A , T 2B , T 3 ) detected by the temperature sensors (13, 13a, 13b, 14, 15), and from the temperature curve to calculate a temperature setpoint for the position of at least one of the further temperature sensors and to compare it with the actual temperature value actually detected by this temperature sensor and from the deviation between the temperature setpoint and the actual temperature value a change in the thermal insulation quality of the Detect container when the deviation is beyond a limit.
    [2]
    2. Device according to claim 1, characterized in that the heat transfer model of the container also takes into account the heat conduction resulting from the construction and material properties of the container.
    [3]
    3. Device according to claim 1 or 2, characterized in that the heat insulation device comprises at least one heat insulation shield (2) and / or a multi-layer insulation (20) with composite layers (21) made of a metal foil 22 and a heat-insulating material (23), the composite layers (21) are optionally designed as a winding with several turns.
    17/27
    [4]
    4. Device according to one of the preceding claims, characterized in that the evaluation unit (18) classifies the detected change in the thermal insulation quality of the container as an increase in pressure in the vacuum chamber (5) when the deviation of the actual temperature value from the desired temperature value by the limit value or more than the temperature setpoint.
    [5]
    5. Device according to one of the preceding claims, characterized in that the evaluation unit (18) classifies the detected change in the thermal insulation quality of the container as damage to the outer wall (1) if the deviation of the actual temperature value from the target temperature value by the limit value or more is above the temperature setpoint.
    [6]
    6. Device according to one of the preceding claims, characterized in that the evaluation unit (18) is designed to determine the temperature of the outer wall (1) from ambient conditions, for which purpose the evaluation unit preferably with a temperature sensor of an external device, in particular the outside temperature sensor of a vehicle , to which the device is attached, is connected and derives the temperature of the outer wall from its temperature signals.
    [7]
    7. Device according to one of the preceding claims, characterized in that the evaluation unit (18) is designed to determine the vacuum pressure in the vacuum chamber (5) from the difference between the temperature setpoint and the actual temperature value, based on previous temperature measurements different known vacuum pressures in the vacuum chamber (5).
    [8]
    8. Device according to one of the preceding claims, characterized in that, in addition or as an alternative to the temperature sensor (14) on the inner wall (3), a pressure sensor (19) is provided in the inner tank, and the evaluation unit (18) is designed to measure the pressure signals of the Receive pressure sensor and determine the temperature in the inner tank from the pressure signals based on the pressure dependence of the boiling temperature at which liquid gas is stored in the inner tank.
    [9]
    9. The device according to claim 8, characterized in that the evaluation unit (18) is designed to classify the change in the pressure measured by the pressure sensor (19) in the inner tank as a transient refueling process if the rate of change exceeds a limit value.
    18/27
    [10]
    10. Device according to one of the preceding claims, characterized in that a fill level sensor (17) is arranged in the inner tank, the fill level signals (f) of which are fed to the evaluation unit (18), the evaluating unit (18) being designed to change the fill level (16) to classify the stored liquid gas (7) as a transient refueling process if the rate of change exceeds a limit value.
    [11]
    11. Device according to one of the preceding claims, characterized in that the evaluation unit (18) is designed to approximate the temperature profile by stringing straight line sections together, each straight line section connecting adjacent actual temperature values detected by the temperature sensors, the evaluation unit (18) The deviation of the actual temperature value at this connection point from the temperature setpoint is derived from an angle (α) at a connection point between two adjacent straight sections.
    [12]
    12. The device according to claim 11, characterized in that the evaluation unit (18) is designed to classify the cause from a rate of change of the angle α, which is proportional to the rate of change of the actual temperature value at this connection point.
    [13]
    13. A method for determining the thermal insulation quality of a double-walled vacuum-insulated container (30, 40), the container having an outer wall (1) facing the surroundings and an inner wall (3) defining an inner tank, one between the outer wall and the inner wall of the double-walled container Vacuum chamber (5) is formed, in which at least one heat insulation device (2, 20) is arranged, characterized in that the container (30, 40) has at least three spaced-apart temperature sensors (13, 13a, 13b, 14, 15), wherein recurring current temperatures (T 1 , T 2 , T 2A , T 2B , T 3 ) of the container (30, 40) are detected, the positions of the temperature sensors (13, 13 a, 13b, 14, 15) being selected from positions on the outer wall (1), the inner wall (3) and / or the heat insulation device (2, 20), with a temperature profile using at least one point, preferably layer by layer, heat Transfer model is calculated on the basis of the construction and material properties of the container and the resulting thermal radiation, which temperature profile at least two of the temperatures detected by the temperature sensors (13, 13a, 13b, 14, 15) (T 1 , T 2 , T 2A , T 2B , T 3 ), and wherein from the temperature curve a temperature setpoint for the position of at least one other of the temperature sensors is calculated and with which actually of
    19/27 this temperature sensor recorded actual temperature value is compared and from the
    Deviation between the temperature setpoint and the actual temperature one
    Change in thermal insulation quality of the container is detected when the
    Deviation is beyond a limit.
    [14]
    14. The method according to claim 13, characterized in that the heat transfer model of the container also takes into account the heat conduction resulting from the construction and material properties of the container.
    [15]
    15. The method according to any one of claims 13 or 14, characterized in that the detected change in the thermal insulation quality of the container is classified as an increase in pressure in the vacuum chamber (5) when the deviation of the actual temperature value from the temperature setpoint is below the limit value or more the temperature setpoint.
    [16]
    16. The method according to any one of claims 13 to 15, characterized in that the detected change in the thermal insulation quality of the container is classified as damage to the outer wall (1) when the deviation of the actual temperature value from the temperature setpoint by the limit or more than that Temperature setpoint.
    [17]
    17. The method according to any one of claims 13 to 16, characterized in that the vacuum pressure in the vacuum chamber (5) is determined from the difference between the temperature setpoint and the actual temperature value, on the basis of previous temperature measurements at different known vacuum pressures in the Vacuum chamber (5).
    [18]
    18. The method according to any one of claims 13 to 17, characterized in that in addition or alternatively to the temperature sensor (14) on the inner wall (3), a pressure sensor (19) is provided in the inner tank, and from the pressure signals, the temperature in the inner tank based on the pressure dependence the boiling temperature at which liquid gas is stored in the inner tank is determined.
    [19]
    19. The method according to claim 18, characterized in that the change in the pressure measured by the pressure sensor (19) in the inner tank is classified as a transient refueling process if the rate of change exceeds a limit value.
    [20]
    20. The method according to any one of claims 13 to 19, characterized in that a fill level sensor (17) is arranged in the inner tank, the change in fill level
    20/27 (16) of the stored liquid gas (7) is classified as a transient refueling process if the rate of change exceeds a limit value.
    [21]
    21. The method according to any one of claims 13 to 20, characterized in that the temperature profile is approximated by stringing straight line sections together, which straight line sections respectively connect adjacent actual temperature values detected by the temperature sensors, with an angle (α) at a connection point between two adjacent straight line sections the deviation of the actual temperature value at this connection point is derived from the temperature setpoint.
    [22]
    22. The method according to claim 21, characterized in that the cause is classified from a rate of change of the angle α, which is proportional to the rate of change of the actual temperature value at this connection point.
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    同族专利:
    公开号 | 公开日
    AU2018207266A1|2019-07-25|
    CN110291325B|2021-10-26|
    US20190368659A1|2019-12-05|
    CN110291325A|2019-09-27|
    BR112019014111A2|2020-02-27|
    AT519232B1|2018-05-15|
    CA3049601A1|2018-07-19|
    EP3568628A1|2019-11-20|
    WO2018129571A1|2018-07-19|
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    EP1357328A2|2002-04-22|2003-10-29|Linde Aktiengesellschaft|Control of the vacuum of double-walled vessels and pipelines|
    JP2006078190A|2004-09-07|2006-03-23|Sumitomo Electric Ind Ltd|Device and method for monitoring vacuum lowering of vacuum insulation structure|
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    CN105308381B|2013-06-21|2017-06-09|川崎重工业株式会社|Liquid gas keeps tank and liquid gas carry vessel|
    CN104122032A|2014-08-18|2014-10-29|太仓派欧技术咨询服务有限公司|Measuring method for quickly judging VIP vacuum degree|
    CN104309603B|2014-09-30|2017-02-15|联合汽车电子有限公司|Method for diagnosing air leakage of vacuum air suction system for providing vacuum degree of brake system|
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    CN108918024A|2018-08-06|2018-11-30|南京市锅炉压力容器检验研究院|One kind is with low-temperature gas cylinder sandwich layer vacuum degree rapid detection method|
    FR3090872B1|2018-12-21|2021-04-23|Gaztransport Et Technigaz|Process for checking the tightness of a sealed and thermally insulating fluid storage tank|
    CN111219598B|2020-01-07|2021-06-01|浙江大学|Vacuum degree detection method and device for vacuum heat-insulation storage tank|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    ATA50028/2017A|AT519232B1|2017-01-16|2017-01-16|Apparatus and method for determining the thermal insulation quality of double-walled vacuum-insulated containers|ATA50028/2017A| AT519232B1|2017-01-16|2017-01-16|Apparatus and method for determining the thermal insulation quality of double-walled vacuum-insulated containers|
    BR112019014111-1A| BR112019014111A2|2017-01-16|2018-01-05|DEVICE AND METHOD FOR DETERMINING THE QUALITY OF THERMAL INSULATION OF DOUBLE-WALL VACUUM INSULATED CONTAINERS|
    US16/478,305| US20190368659A1|2017-01-16|2018-01-05|Device and method for determining the thermal insulation quality of twin-walled, vacuum-insulated containers|
    AU2018207266A| AU2018207266A1|2017-01-16|2018-01-05|Device and method for determining the heat insulation quality of dual-wall, vacuum-insulated containers|
    PCT/AT2018/060001| WO2018129571A1|2017-01-16|2018-01-05|Device and method for determining the thermal insulation quality of twin-walled, vacuum-insulated containers|
    CA3049601A| CA3049601A1|2017-01-16|2018-01-05|Device and method for determining the heat insulation quality of dual-wall, vacuum-insulated containers|
    EP18700631.7A| EP3568628A1|2017-01-16|2018-01-05|Device and method for determining the thermal insulation quality of twin-walled, vacuum-insulated containers|
    CN201880006972.8A| CN110291325B|2017-01-16|2018-01-05|Device and method for determining the insulation quality of a double-walled vacuum-insulated container|
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