Hydrogen carrier self-heating synthesis system

Abstract

The utility model discloses a flexible system for wide-load fluctuation operation in a hydrogen carrier self-heating synthesis process technology. The system comprises a hydrogen carrier compound preparation device, a 1 # heat exchanger, a 2 # heat exchanger, a flow detection device, a first regulating valve, a second regulating valve, a temperature detection device and a control device, and the hydrogen carrier compound preparation device is sequentially connected with the 1 # heat exchanger and the 2 # heat exchanger. The temperature detection device is connected with an inlet of the hydrogen carrier compound preparation device, the control device is used for detecting results of the flow detection device and setting a first temperature target value and a second temperature target value, the first adjusting valve or the second adjusting valve adjusts the opening degree according to the first temperature target value, and the second adjusting valve adjusts the opening degree according to the second temperature target value. The hydrogen carrier compound preparation device operates at a constant temperature or a near constant temperature in a variable load state, wherein the load moves along with the source; according to the control system, rapid and timely flexible load adjustment is achieved, and efficient, safe and stable operation of the system is achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to hydrogen carrier synthesis technical field, concretely relates to a hydrogen carrier self heating synthesis system. BACKGROUND

[0002] The development of hydrogen energy industry has a profound impact on the transformation of energy structure and the reduction of carbon emissions in China and even the world. As a chemical raw material and clean, efficient and renewable fuel, hydrogen is gradually becoming a key factor in promoting energy revolution. It is necessary to further strengthen the development of renewable energy such as water energy, solar energy, wind energy and biomass energy to produce hydrogen, so as to reduce the dependence on primary energy such as fossil fuels and reduce the emission of greenhouse gases, so as to achieve the goal of sustainable development.

[0003] In view of the potential of green hydrogen energy in various terminal applications, this energy is expected to become one of the main energy commodities in the future. However, the physical properties of hydrogen gas pose serious challenges to its large-scale application, storage and transportation.

[0004] At present, a variety of efficient hydrogen application, storage and transportation technologies have been developed, and these technologies are still under continuous development. In order to achieve high energy density storage and transportation of hydrogen, hydrogen needs to be processed, such as compression, deep cooling to achieve liquid hydrogen storage, organic liquid hydrogen storage, solid adsorption hydrogen storage or conversion into hydrogen carrier through chemical reaction. The preparation of hydrogen carrier involves chemical reaction between hydrogen and suitable reactants, which generates hydrogen-rich hydrogen carrier compounds, thereby achieving safe, convenient and efficient storage and transportation of hydrogen.

[0005] In the process of hydrogen carrier synthesis, green hydrogen prepared by wind power and photovoltaic power generation can be used as a chemical raw material, but the process of preparing green hydrogen is affected by the volatility, randomness, intermittency, seasonal differences and regional distribution differences of wind power and photovoltaic power generation, which leads to the volatility, randomness and intermittency of the hydrogen carrier synthesis process, and further makes the hydrogen carrier synthesis process unstable. In order to make the hydrogen carrier synthesis process fast, timely and match the volatility, randomness and intermittency of wind power and photovoltaic power generation in the preparation of green hydrogen, it is necessary to optimize the hydrogen carrier synthesis process system and control under the condition of meeting the safety and economic requirements, realize flexible regulation and control in a timely manner, so as to cope with the unstable characteristics of renewable energy, and realize the timely, efficient, safe and stable "constant temperature" or "near constant temperature" operation of hydrogen carrier synthesis. UTILITY MODEL CONTENTS

[0006] The utility model aims at overcoming the defects in the prior art, and provides a hydrogen carrier self heating synthesis system to improve the matching degree of hydrogen carrier self heating synthesis system and renewable energy volatility.

[0007] In order to achieve the above object, the technical scheme of the utility model is designed as a hydrogen carrier self-heating synthesis system, which comprises a hydrogen carrier compound preparation device, a 1# heat exchanger, a 2# heat exchanger, a flow detection device, a temperature detection device, a synthesis gas inlet pipeline, a synthesis gas outlet pipeline;

[0008] The synthesis gas is prepared by the hydrogen carrier compound preparation device reaction to obtain reaction gas;

[0009] The hydrogen carrier compound preparation device, the 1# heat exchanger and the 2# heat exchanger are sequentially connected by pipelines in the flow direction of the reaction gas, and the reaction gas is discharged after passing through the 2# heat exchanger;

[0010] The outlet end of the synthesis gas inlet pipeline is connected with the gas inlet end of the 2# heat exchanger;

[0011] One end of the synthesis gas outlet pipeline is connected with the gas outlet end of the 2# heat exchanger, and the other end is connected with the gas inlet end of the hydrogen carrier compound preparation device;

[0012] The flow detection device is installed on the synthesis gas inlet pipeline;

[0013] The temperature detection device is installed on the synthesis gas outlet pipeline.

[0014] Further, it further comprises a first regulating valve, the first regulating valve is provided in parallel with the 1# heat exchanger, and the two ends of the first regulating valve are respectively communicated with the pipelines on the two sides of the 1# heat exchanger.

[0015] Further, it further comprises a second regulating valve, the second regulating valve is provided in parallel with the 2# heat exchanger, and the two ends of the second regulating valve are respectively connected with the synthesis gas inlet pipeline and the synthesis gas outlet pipeline through pipelines.

[0016] Further, the synthesis gas is divided into two streams after passing through the flow detection device, and then passes through the second regulating valve and the 2# heat exchanger.

[0017] Further, it further comprises a control device, the control device is used for collecting the temperature detection result of the temperature detection device and the flow detection result of the flow detection device, and adjusting the opening degree of the first regulating valve and / or the second regulating valve according to the temperature detection result of the temperature detection device and the flow detection result of the flow detection device.

[0018] Further, the control device judges whether the flow detection result of the flow detection device is greater than or equal to a first preset threshold value according to the flow detection result of the flow detection device,

[0019] If the flow detection result of the flow detection device is greater than or equal to the first preset threshold value, the first regulating valve is closed, and the opening degree of the second regulating valve is adjusted to reach the second target value of the inlet temperature of the hydrogen carrier compound preparation device;

[0020] If less than the first preset threshold, adjust the opening degree of the first adjusting valve or / and the second adjusting valve to reach the first target value of the syngas flow and the hydrogen carrier compound preparation device inlet temperature; Specifically, the control device sets the first target value of the hydrogen carrier compound preparation device inlet temperature according to the syngas flow and the hydrogen carrier compound preparation device inlet feed temperature curve, and the first adjusting valve or the second adjusting valve adjusts the opening degree according to the first target value, so that the hydrogen carrier compound preparation device runs in time, efficiently, safely and stably in "constant temperature" or "near constant temperature".

[0021] Further, the hydrogen carrier compound preparation device is at least one of an ammonia synthesis reaction device and a methanol synthesis reaction device.

[0022] A control method of a hydrogen carrier autothermal synthesis system, comprising the following steps:

[0023] S10: The temperature detection result of the temperature detection device and the flow detection result of the flow detection device are collected by the control device, and whether the flow detection result of the flow detection device is greater than or equal to the first preset threshold is judged,

[0024] S11A: If greater than or equal to the first preset threshold, the first adjusting valve is closed, and the second adjusting valve adjusts the opening degree according to the second target value of the temperature;

[0025] S11B: If less than the first preset threshold, the control device sets the first target value of the hydrogen carrier compound preparation device inlet temperature according to the syngas flow and the hydrogen carrier compound preparation device inlet feed temperature curve, and the first adjusting valve or / and the second adjusting valve adjusts the opening degree according to the first target value, so that the hydrogen carrier compound preparation device runs in time, efficiently, safely and stably in "constant temperature" or "near constant temperature".

[0026] Further, the specific steps of step S11B are as follows:

[0027] S111: The second adjusting valve adjusts the opening degree according to the first target value to increase the syngas temperature at the inlet of the hydrogen carrier compound preparation device;

[0028] S112: Whether the opening degree of the second adjusting valve is 0 is judged;

[0029] S113: If yes, the first adjusting valve adjusts the opening degree according to the first target value, so that the high-temperature reaction gas at the outlet of the hydrogen carrier compound preparation device is divided, the syngas feed temperature at the inlet of the hydrogen carrier compound preparation device is further increased, and the hydrogen carrier compound preparation device runs in time, efficiently, safely and stably in "constant temperature" or "near constant temperature";

[0030] If no, step S111 is continued.

[0031] The utility model discloses, since the reaction of synthetic hydrogen carrier such as synthetic ammonia, synthetic methanol etc. is the exothermic reaction that can realize self-heating, leads to hydrogen carrier compound preparation device export temperature higher, with the reaction gas direct heat exchange with the feed synthesis gas, to improve the synthesis gas feed temperature, further to make hydrogen carrier compound preparation device " the timely, efficient, safe, stable'constant temperature'or'near constant temperature'operation of source dynamic.

[0032] When normal load operation, hydrogen carrier compound preparation device export's high temperature reaction gas carries out heat recovery through 1# heat exchanger, and the synthesis gas is heated through 2# heat exchanger using the heat of reaction gas, simultaneously control second regulating valve makes the synthesis gas that has not passed through 2# heat exchanger and the synthesis gas after passing through 2# heat exchanger mix, further, hydrogen carrier compound preparation device inlet temperature reaches the temperature required when reaction of synthesis gas normal flow, to make hydrogen carrier compound preparation device " the timely, efficient, safe, stable'constant temperature'or'near constant temperature'operation of source dynamic.

[0033] When low load operation, the reaction gas from hydrogen carrier compound preparation device also reduces, and the heat it carries also reduces, at this time, the first regulating valve of hydrogen carrier compound preparation device export is opened, and the high temperature reaction gas of hydrogen carrier compound preparation device export is shunted, one high temperature reaction gas passes through 1# heat exchanger and temperature drops, another high temperature reaction gas passes through first regulating valve and temperature does not change, and the reaction gas of two high temperature reaction gas mixes after 2# heat exchanger reaction gas inlet and improves 2# heat exchanger reaction gas inlet temperature, and the synthesis gas feed temperature of hydrogen carrier compound preparation device inlet is further raised, thereby reaches the temperature corresponding to the synthesis gas flow and hydrogen carrier compound preparation device inlet temperature curve under low load state, to make hydrogen carrier compound preparation device " the timely, efficient, safe, stable'constant temperature'or'near constant temperature'operation of source dynamic.

[0034] The utility model discloses the advantages and beneficial effects are:

[0035] (1) hydrogen carrier compound preparation device can be in variable load condition and timely, efficient, safe, stable'constant temperature'or'near constant temperature'operation, realizes system " the timely, efficient, safe, stable operation of source dynamic " of purpose of purpose.

[0036] (2) through hydrogen carrier compound preparation device export and set up first regulating valve, can be in variable load condition and timely further heating of feed synthesis gas, to solve the time lag problem existing in 1# heat exchanger heat exchange process.

[0037] (3) in the low load operation state, the temperature corresponding to the syngas flow is selected from the temperature curve of the syngas corresponding to the syngas flow at the inlet of the hydrogen carrier compound preparation device, and the first target value is set, the fuzzy self-adaptive PID in the control device (compared with the traditional PID, the calculation method has the advantages of small overshoot and faster response speed) calculates the result according to the first target value, and the first regulating valve adjusts the opening degree at any time according to the calculation result, so as to reduce the time delay and inertia existing in the heat exchange process of the 2# heat exchanger, improve the robustness and adaptability of the whole feeding system, and realize the timely, efficient, safe and stable "constant temperature" or "near constant temperature" operation of the hydrogen carrier compound preparation device. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 A structure schematic view of a hydrogen carrier self-heating synthesis system provided by the embodiment of the present application is provided.

[0039] Figure 2 A structure schematic view of a green ammonia synthesis system provided by the embodiment of the present application is provided.

[0040] Figure 3 A control method logic flow schematic view of a hydrogen carrier self-heating synthesis system provided by the embodiment of the present application is provided.

[0041] Figure 4 A syngas flow and ammonia synthesis reaction device inlet syngas corresponding temperature curve for "constant temperature" or "near constant temperature" operation of a 2wt / a ammonia synthesis reaction device provided by the embodiment of the present application, the curve is a basic curve obtained by calculating the corresponding relationship between different syngas flow and hydrogen carrier compound preparation device 100 inlet syngas temperature, through long-term accumulation, optimization and verification of actual operation data, on the basis of theoretical analysis and modeling of the ammonia synthesis process.

[0042] BRIEF DESCRIPTION OF DRAWINGS

[0043] 100-hydrogen carrier compound preparation device; 101-syngas inlet pipeline; 102-syngas outlet pipeline; 200-1# heat exchanger; 300-2# heat exchanger; 400-flow detection device; 401-temperature detection device; 402-first regulating valve; 403-second regulating valve; 500-controller; 1000-ammonia synthesis reaction device; 1001-syngas inlet pipeline; 1002-syngas outlet pipeline; 2000-1# heat exchanger; 3000-2# heat exchanger; 4000-flow detection device; 4001-temperature detection device; 4002-first regulating valve; 4003-second regulating valve; 5000-controller. DETAILED DESCRIPTION

[0044] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0045] like Figure 1 As shown, a hydrogen carrier autothermal synthesis system includes a hydrogen carrier compound preparation device 100, a heat exchanger 200 (1#), a heat exchanger 300 (2#), a flow detection device 400, a temperature detection device 401, a syngas inlet pipe 101, and a syngas outlet pipe 102.

[0046] Syngas is reacted in the hydrogen carrier compound preparation apparatus 100 to prepare reaction gas;

[0047] The hydrogen carrier compound preparation apparatus 100, the No. 1 heat exchanger 200 and the No. 2 heat exchanger 300 are connected in sequence by pipelines in the direction of reaction gas flow, and the reaction gas is discharged after passing through the No. 2 heat exchanger 300.

[0048] The outlet end of the synthesis gas inlet pipe 101 is connected to the inlet end of the No. 2 heat exchanger 300;

[0049] One end of the synthesizer outlet pipe 102 is connected to the outlet end of the No. 2 heat exchanger 300, and the other end is connected to the inlet end of the hydrogen carrier compound preparation device 100.

[0050] The flow detection device 400 is installed on the syngas inlet pipe 101;

[0051] The temperature detection device 401 is installed on the syngas outlet pipe 102.

[0052] As a preferred embodiment of the above technical solution, it further includes a first regulating valve 402, which is connected in parallel with the No. 1 heat exchanger 200, and both ends of the first regulating valve 402 are respectively connected to the pipes on both sides of the No. 1 heat exchanger 200.

[0053] As a preferred embodiment of the above technical solution, it further includes a second regulating valve 403, which is connected in parallel with the No. 2 heat exchanger 300, and the two ends of the second regulating valve 403 are connected to the syngas inlet pipe 101 and the syngas outlet pipe 102 respectively through pipes.

[0054] As a preferred embodiment of the above technical solution, the synthesis gas, after passing through the flow detection device 400, is then diverted through the second regulating valve 403 and the #2 heat exchanger 300.

[0055] As the preferred technical solution of the above, it further comprises a control device 500, which is used to collect the temperature detection result of the temperature detection device 401 and the flow detection result of the flow detection device 400, and adjust the opening degree of the first regulating valve 402 and / or the second regulating valve 403 according to the temperature detection result of the temperature detection device 401 and the flow detection result of the flow detection device 400.

[0056] As the preferred technical solution of the above, the control device 500 judges whether the flow detection result of the flow detection device 400 is greater than or equal to a first preset threshold value according to the flow detection result of the flow detection device 400,

[0057] If it is greater than or equal to the first preset threshold value, the first regulating valve 402 is closed, and the opening degree of the second regulating valve 403 is adjusted to reach the second target value of the inlet temperature of the hydrogen carrier compound preparation device 100.

[0058] If it is less than the first preset threshold value, the opening degree of the first regulating valve 402 or / and the second regulating valve 403 is adjusted to reach the first target value of the inlet temperature of the hydrogen carrier compound preparation device 100 and the flow of the synthesis gas; Specifically, the control device 500 sets the first target value of the temperature of the inlet temperature of the hydrogen carrier compound preparation device 100 according to the inlet temperature curve of the hydrogen carrier compound preparation device 100, and the first regulating valve 402 or the second regulating valve 403 adjusts the opening degree according to the first target value, so that the hydrogen carrier compound preparation device 100 runs at "constant temperature" or "near constant temperature".

[0059] As the preferred technical solution of the above, the hydrogen carrier compound preparation device 100 is at least one of an ammonia synthesis reaction device and a methanol synthesis reaction device.

[0060] A control method of a hydrogen carrier self-heating synthesis system, comprising the following steps:

[0061] S10: Collect the temperature detection result of the temperature detection device 401 and the flow detection result of the flow detection device 400 by the control device 500, and judge whether the flow detection result of the flow detection device 400 is greater than or equal to a first preset threshold value according to the flow detection result of the flow detection device 400,

[0062] S11A: If it is greater than or equal to the first preset threshold value, the first regulating valve 402 is closed, and the opening degree of the second regulating valve 403 is adjusted according to the second target value of the temperature;

[0063] S11B: If the temperature is less than the first preset threshold, the control device 500 sets a first target value for the inlet temperature of the hydrogen carrier compound preparation device 100 according to the inlet feed temperature curve of the hydrogen carrier compound preparation device 100, and the first adjusting valve 402 or / and the second adjusting valve 403 adjusts the opening degree according to the first target value, so that the hydrogen carrier compound preparation device 100 is operated at constant temperature or near constant temperature.

[0064] As a preferred embodiment of the above technical solution, the specific steps of step S11B are as follows:

[0065] S111: The second adjusting valve 403 adjusts the opening degree according to the first target value, and the inlet synthesis gas temperature of the hydrogen carrier compound preparation device 100 is increased.

[0066] S112: It is judged whether the opening degree of the second adjusting valve 403 is 0.

[0067] S113: If yes, the first adjusting valve 402 adjusts the opening degree according to the first target value, so that the high-temperature reaction gas at the outlet of the hydrogen carrier compound preparation device 100 is branched, the inlet synthesis gas feed temperature of the hydrogen carrier compound preparation device 100 is further increased, and the ammonia synthesis reaction device is operated at constant temperature or near constant temperature.

[0068] If no, the step S111 is continued.

[0069] (I) Related term definition

[0070] In the utility model, the constant temperature or near constant temperature operation refers to adjusting the temperature of the synthesis gas entering the hydrogen carrier compound preparation device 100, so that the temperature of the hydrogen carrier self-heating synthesis reaction device (the synthesis equipment body and the catalyst bed) is constant or approximately constant, and the characteristic is that the outlet synthesis gas temperature of the hydrogen carrier compound preparation device 100 is constant or approximately constant.

[0071] The first target value refers to the required temperature value of the inlet synthesis gas of the hydrogen carrier compound preparation device 100 obtained from the synthesis gas flow and the inlet feed temperature curve of the hydrogen carrier compound preparation device 100 (such as Figure 4 ), which is a basic curve obtained by calculating the corresponding relationship between different synthesis gas flow and the inlet synthesis gas temperature of the hydrogen carrier compound preparation device 100 through theoretical analysis, modeling and other processes of the hydrogen carrier compound synthesis process, and then through long-term accumulation, optimization and verification of actual operation data.

[0072] Second target value: the temperature required for the hydrogen carrier compound preparation device 100 to run efficiently, safely and stably at a constant temperature or near constant temperature when the normal flow of synthesis gas or the flow of synthesis gas is higher than the first preset threshold value. The second target value can be obtained by the curve of the flow of synthesis gas and the inlet temperature of the hydrogen carrier compound preparation device 100.

[0073] First preset threshold value: in the case that the first adjusting valve 402 is closed, the opening of the second adjusting valve 403 is adjusted so that the flow of synthesis gas is the lowest (the first preset threshold value can be greater than or equal to the lowest flow value) when the hydrogen carrier compound preparation device 100 runs at a constant temperature or near constant temperature. Under normal load, the initial value is obtained by the curve of the flow of synthesis gas and the inlet temperature of the hydrogen carrier compound preparation device 100 when the inlet temperature of the hydrogen carrier compound preparation device 100 does not change (in the actual calculation process, the inlet temperature of the hydrogen carrier compound preparation device changes correspondingly with the change of the flow of synthesis gas, and in the utility model, the inlet temperature is considered to be unchanged when the temperature difference is within 1 DEG C under 100% load operation, and the flow range corresponding to the temperature difference range will not be used in actual operation. The first adjusting valve 402 will not affect the normal operation of the device. ), and the optimal value is obtained through long-term accumulation, optimization and verification in the actual operation process.

[0074] Normal load operation: the flow of synthesis gas is higher than or equal to the first preset threshold value, and the inlet temperature of the hydrogen carrier compound preparation device 100 does not change, so that the hydrogen carrier compound preparation device 100 can run efficiently, safely and stably at a constant temperature or near constant temperature even if the flow of synthesis gas fluctuates.

[0075] Low load operation: the hydrogen carrier compound preparation device 100 can also run at a constant temperature or near constant temperature under the condition that the flow of synthesis gas is lower than the first preset threshold value.

[0076] (II) The curve of the flow of synthesis gas and the inlet temperature of the hydrogen carrier compound preparation device

[0077] The hydrogen carrier compound preparation device in the utility model refers to a synthesis tower.

[0078] The utility model obtains the basic curve of the corresponding relationship between the flow of synthesis gas and the inlet temperature of the hydrogen carrier compound preparation device 100 through the following theoretical analysis, modeling and calculation.

[0079] Firstly, the heat required for the synthesis gas of the hydrogen carrier compound preparation device (synthesis tower) to enter the shell of the synthesis tower and enter the catalyst frame, that is, the heat required for the synthesis gas to be heated to the activation temperature, is calculated according to the formula

[0080] ) ①,

[0081] wherein: Qsynth is the heat of the synthesis gas to be heated to the activation temperature of the catalyst,

[0082] Hsynth is the enthalpy of the synthesis gas entering the catalyst frame,

[0083] Hsynthshell is the enthalpy of the synthesis gas entering the shell of the synthesis tower,

[0084] msynth is the mass flow of the synthesis gas,

[0085] Cp,synth is the specific heat capacity of the synthesis gas entering the catalyst frame (calculated from the composition and temperature of the synthesis gas by consulting relevant thermodynamic data tables or empirical formulae),

[0086] Cp,synthshell is the specific heat capacity of the synthesis gas entering the shell of the synthesis tower,

[0087] Tsynthshell is the temperature of the synthesis gas entering the shell of the synthesis tower,

[0088] Tsynthframe is the temperature of the synthesis gas entering the catalyst frame.

[0089] Then, the heat of the catalyst frame outlet gas to be heated to the temperature of the outlet of the shell of the synthesis tower is calculated, and the calculation formula is

[0090] Qsynthshellframe = msynthframe x (Cp,synthframe - Cp,synthshellframe) x (Tsynthframe - Tsynthshellframe) ②,

[0091] wherein: Qsynthshellframe is the heat of the catalyst frame reaction gas to be heated to the temperature of the outlet of the synthesis tower,

[0092] Hsynthshellframe is the enthalpy of the reaction gas exiting the shell of the synthesis tower,

[0093] Hsynthframe is the enthalpy of the reaction gas at the temperature of the inlet gas entering the catalyst frame,

[0094] msynthframe is the mass flow of the reaction gas (assuming that the material loss in the reactor is not taken into account, it is equal to the mass flow of the synthesis gas),

[0095] Cp,synthshellframe is the specific heat capacity of the reaction gas exiting the shell of the synthesis tower,

[0096] Cp,synthframe is the specific heat capacity of the reaction gas at the temperature of the inlet gas entering the catalyst frame,

[0097] Tsynthshellframe is the temperature of the reaction gas exiting the shell of the synthesis tower,

[0098] The temperature of the reaction gas entering the catalyst frame is equal to the temperature of the synthesis gas entering the catalyst frame, i.e. The temperature of the reaction gas entering the catalyst frame is equal to the temperature of the synthesis gas entering the catalyst frame, i.e. .

[0099] Then, the heat loss of the synthesis tower to the surroundings is calculated, and the calculation formula is

[0100] ③,

[0101] In the formula: is the heat loss of the synthesis tower,

[0102] F is the heat dissipation area of the synthesis tower,

[0103] is the wall temperature of the synthesis tower,

[0104] is the ambient temperature,

[0105] is the heat transfer coefficient of the outer surface of the tower wall to the air,

[0106] is obtained from the empirical formula .

[0107] The calculation formula of the energy balance equation of the synthesis tower is

[0108] ④,

[0109] where is the heat of reaction.

[0110] Assuming that the bed temperature remains unchanged at different loads to maintain stable reaction (the bed temperature remaining unchanged means that the temperature in the hydrogen carrier compound preparation device (including the synthesis tower equipment body and the catalyst bed) is unchanged or approximately unchanged by adjusting the temperature of the synthesis tower inlet gas 101, and the characteristic is that the outlet reaction gas temperature of the device is unchanged or approximately unchanged), the heat loss of the synthesis tower at low load will be consistent with the heat loss at rated load, unchanged, unchanged.

[0111] The above formulas ①-④ can be used to calculate the corresponding synthesis gas inlet temperature of different synthesis gas mass flow rates , and a curve graph can be drawn according to the synthesis gas inlet flow rate (mass flow rate or volume flow rate) and the synthesis gas inlet temperature. The first preset threshold initial value, the first target value and the second target value of the reaction can be obtained from the curve graph.

[0112] (Three) Examples

[0113] Among the many hydrogen energy carriers, ammonia has a volume hydrogen content of up to 121 kg H2 / m 3 , which is 2.6 times that of methylcyclohexane (MCH, a typical liquid organic hydride). At the same time, the temperature and pressure conditions for storing liquid ammonia are much lower than those for storing liquid hydrogen. It can be liquefied at low pressure of about 0.8 MPa or at low temperature of -33℃ under normal pressure, and transported and stored. The embodiments of the present application provide a control method based on a key part of a hydrogen carrier self-heating synthesis system, taking green ammonia as an example:

[0114] Due to the instability of renewable energy, the production of raw hydrogen gas for green ammonia synthesis is unstable. The existing ammonia synthesis system control and method is generally based on stable operating control, which requires stable raw material sources and stable process operating parameters. The control method of the traditional Haber-Bosch process cannot achieve rapid and timely adjustment of the "load following source" with wide load fluctuations of the raw gas. For the process of using renewable energy to decompose water to produce green hydrogen, and then using green hydrogen as raw material to synthesize green ammonia, due to the instability of renewable energy, the production of raw hydrogen gas is unstable, and the synthesis of green ammonia is also unstable. If the adjustment and control process is improper, it will cause the synthesis of green ammonia to lose control, or the ammonia net value may decrease to zero, resulting in high operating costs, or the catalyst may be overburned and deactivated, and the device cannot operate. Therefore, there is an urgent need for a control method that can achieve flexible adjustment of the synthesis ammonia system under wide load to achieve "constant temperature" or "near constant temperature" timely, efficient, safe and stable operation of the synthesis ammonia reaction device under variable load.

[0115] As shown in Figure 2 , it comprises an ammonia synthesis reaction device 1000, a 1# heat exchanger 2000, a 2# heat exchanger 3000, a flow detection device 4000, a temperature detection device 4001, a first adjusting valve 4002, a second adjusting valve 4003, a synthesis gas inlet pipeline 1001, a synthesis gas outlet pipeline 1002, a controller 5000, and a reaction gas prepared by reacting the synthesis gas through the ammonia synthesis reaction device 1000;

[0116] The ammonia synthesis reaction device 1000, the 1# heat exchanger 2000 and the 2# heat exchanger 3000 are connected in sequence by pipeline in the flow direction of the reaction gas, and the reaction gas is discharged after passing through the 2# heat exchanger 3000;

[0117] The outlet end of the synthesis gas inlet pipeline 1001 is connected with the gas inlet end of the 2# heat exchanger 3000;

[0118] One end of the synthesis gas outlet pipeline 1002 is connected with the gas outlet end of the 2# heat exchanger 3000, and the other end is connected with the gas inlet end of the ammonia synthesis reaction device 1000;

[0119] The flow detection device 4000 is installed on the syngas inlet pipeline 1001 and is used to detect the syngas flow;

[0120] The temperature detection device 4001 is installed on the syngas outlet pipeline 1002 and is used to detect the inlet temperature of the ammonia synthesis reaction device 1000;

[0121] The first regulating valve 4002 is arranged in parallel with the 1# heat exchanger 2000, and the two ends of the first regulating valve 4002 are respectively connected with the pipelines on the two sides of the 1# heat exchanger 2000;

[0122] The second regulating valve 4003 is arranged in parallel with the 2# heat exchanger 3000, and the two ends of the second regulating valve 4003 are respectively connected with the syngas inlet pipeline 1001 and the syngas outlet pipeline 1002 through pipelines; the syngas passes through the flow detection device 4000 and then is branched to pass through the second regulating valve 4003 and the 2# heat exchanger 3000; the flow detection device 4000 is used to detect the syngas flow;

[0123] The control device 5000 is used to collect the temperature detection result of the temperature detection device 4001 and the flow detection result of the flow detection device 4000, and adjust the opening degree of the first regulating valve 4002 or / and the second regulating valve 4003 according to the temperature detection result of the temperature detection device 4001 and the flow detection result of the flow detection device 4000.

[0124] Specifically, the control method comprises the following steps:

[0125] S10: collecting, by the control device 5000, the temperature detection result of the temperature detection device 4001 and the flow detection result of the flow detection device 4000, and judging whether the flow detection result of the flow detection device 4000 is greater than or equal to a first preset threshold value,

[0126] S11A: if the flow detection result of the flow detection device 4000 is greater than or equal to the first preset threshold value, closing the first regulating valve 4002 and adjusting the opening degree of the second regulating valve 4003 according to a second target temperature value;

[0127] S11B: if the flow detection result of the flow detection device 4000 is less than the first preset threshold value, setting, by the control device 5000, a first target temperature value for the inlet temperature of the ammonia synthesis reaction device 1000 according to a syngas flow and ammonia synthesis reaction device 1000 inlet temperature curve, and adjusting the opening degree of the first regulating valve 4002 or / and the second regulating valve 4003 according to the first target value, so as to enable the ammonia synthesis reaction device 1000 to be timely, efficient, safe and stable in "constant temperature" or "near constant temperature" operation;

[0128] The specific steps of step S11B are as follows:

[0129] S111: The second regulating valve 4003 adjusts its opening according to the first target value to increase the inlet synthesis gas temperature of the ammonia synthesis reaction unit 1000;

[0130] S112: Determine if the opening degree of the second regulating valve 4003 is 0;

[0131] S113: If so, the first regulating valve 4002 is activated to adjust the opening according to the first target value, so that the high-temperature reaction gas at the outlet of the ammonia synthesis reactor 1000 is diverted, and the inlet temperature of the synthesis gas in the ammonia synthesis reactor 1000 is further increased, so that the ammonia synthesis reactor can operate in a timely, efficient, safe and stable "constant temperature" or "near constant temperature" manner.

[0132] If not, continue with step S111.

[0133] "Constant temperature" or "near constant temperature" operation, first target value, second target value, first preset threshold, normal load operation, low load operation—these terms have been annotated above and will not be repeated here. In Examples 1 and 2, the hydrogen carrier compound preparation device refers to the ammonia synthesis reaction device.

[0134] Example 1:

[0135] like Figures 2-4 As shown, when the 2wt / a ammonia synthesis unit is operating at normal load, the flow rate of synthesis gas (a mixture of hydrogen and nitrogen in a 3:1 ratio) is 22410 Nm³. 3 / h (100% load), with an initial temperature of 140℃, the high-temperature reaction gas at the outlet of the ammonia synthesis reactor 1000 is 435℃. Heat is recovered through heat exchanger 2000. The synthesis gas is heated by utilizing the heat of the reaction gas through heat exchanger 3000. The second regulating valve 4003 is controlled to mix the synthesis gas that has not passed through heat exchanger 3000 and the synthesis gas that has passed through heat exchanger 3000. Furthermore, the inlet temperature of the ammonia synthesis reactor 1000 reaches the temperature required for the reaction when the synthesis gas flows at normal flow rate, which is 181℃. This enables the ammonia synthesis reactor 1000 to operate in a timely, efficient, safe, and stable "constant temperature" or "near constant temperature" manner, with the load following the source.

[0136] S10: After the control device 5000 collects the flow detection result from the flow detection device 4000, it determines that the flow rate is greater than or equal to the first preset threshold of 19944.9 m. 3 / h (by Figure 4 The critical point where the temperature difference between the inlet temperature of the ammonia synthesis reactor at 89% full load flow and the temperature at 100% load flow is 1℃ is obtained. Through long-term data accumulation, optimization, and verification during actual operation, an optimal value is obtained, which is defined here as the first preset threshold.

[0137] S11A: Close the first regulating valve 4002, while the second regulating valve 4003 adjusts the opening degree according to the second target value 181℃ of the ammonia synthesis reactor 1000 inlet temperature, and maintains the ammonia synthesis reactor 1000 inlet synthesis gas temperature at 181℃, so that the ammonia synthesis reactor 1000 can run in time, high efficiency, safety and stability "constant temperature" or "near constant temperature";

[0138] Example two:

[0139] As shown in Figures 2-4 , when the 2wt / a synthetic ammonia production device is in low load production, the synthesis gas (hydrogen and nitrogen mixed at a ratio of 3 to 1) flow is 8964m 3 / h (40% load), the initial temperature is 140℃, and the reaction gas coming out of the ammonia synthesis reactor 1000 is also reduced, and the heat carried by the reaction gas is also reduced. At this time, the first regulating valve 4002 at the outlet of the ammonia synthesis reactor 1000 is opened, so that the high-temperature reaction gas at the outlet of the ammonia synthesis reactor 1000 is divided into two streams. One stream of high-temperature reaction gas passes through the 1# heat exchanger 2000 to reduce the temperature, and the other stream of high-temperature reaction gas passes through the first regulating valve 4002 without changing the temperature. The two streams of reaction gas are mixed at the inlet of the 2# heat exchanger 3000 to increase the inlet temperature of the 2# heat exchanger 3000, so that the inlet temperature of the ammonia synthesis reactor 1000 is further increased, so that the inlet temperature of the ammonia synthesis reactor 1000 is 193.7℃ (see the synthesis gas flow and the ammonia synthesis reactor 1000 inlet temperature corresponding temperature curve, the inlet temperature corresponding to 40% flow is 193.7℃), so that the ammonia synthesis reactor 1000 can run in time, high efficiency, safety and stability "constant temperature" or "near constant temperature".

[0140] S10: The control device 5000 collects the flow detection results of the flow detection device 4000, and judges that the flow is less than the first preset threshold value 19944.9Nm 3 / h (from Figure 4 the full load flow of 89% is the critical point of the temperature difference of 1℃ corresponding to the flow when running at 100% load, and the optimal value is obtained through long-term accumulation, optimization and verification in the actual running process, which is defined as the first preset threshold value);

[0141] If yes, continue to execute S111, which indicates that the flow rate of the synthesis gas at this time is lower than the first preset threshold value, and as the flow rate of the synthesis gas decreases, the reaction heat of the ammonia synthesis reaction device 1000 also decreases, and the second regulating valve 4003 is adjusted according to the first target value 193.7℃ (see the synthesis gas flow rate and the ammonia synthesis reaction device 1000 inlet temperature corresponding temperature curve, and the inlet temperature corresponding to the 40% flow rate is 193.7℃, which is defined as the first target value) to further improve the inlet synthesis gas temperature of the ammonia synthesis reaction device 1000.

[0142] S112: whether the opening degree of the second regulating valve 4003 is 0;

[0143] S113: if yes, the first regulating valve 4002 is started, the fuzzy self-adaptive PID in the control device calculates the result according to the first target value 193.7℃, and the first regulating valve 4002 adjusts the opening degree according to the calculation result, so that the high-temperature reaction gas at the outlet of the ammonia synthesis reaction device 1000 is branched, the inlet synthesis gas feed temperature of the ammonia synthesis reaction device 1000 is further increased, and the ammonia synthesis reaction device 1000 is in time, efficient, safe and stable "constant temperature" or "near constant temperature" operation;

[0144] If no, continue to execute S111.

[0145] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled persons in the technical field, some improvements and refinements can be made without departing from the technical principles of the present application, and these improvements and refinements should also be regarded as the protection range of the present application.

Claims

1. A hydrogen carrier self-heating synthesis system, characterized in that, comprising a hydrogen carrier compound preparation device (100), a 1# heat exchanger (200), a 2# heat exchanger (300), a flow detection device (400), a temperature detection device (401), a synthesis gas inlet pipeline (101), a synthesis gas outlet pipeline (102); synthesis gas is prepared by reaction of the hydrogen carrier compound preparation device (100); the hydrogen carrier compound preparation device (100), the 1# heat exchanger (200) and the 2# heat exchanger (300) are connected in sequence by pipeline in the flow direction of the reaction gas, and the reaction gas is discharged after passing through the 2# heat exchanger (300); the outlet end of the synthesis gas inlet pipeline (101) is connected with the gas inlet end of the 2# heat exchanger (300); one end of the synthesis gas outlet pipeline (102) is connected with the gas outlet end of the 2# heat exchanger (300), and the other end is connected with the gas inlet end of the hydrogen carrier compound preparation device (100); the flow detection device (400) is installed on the synthesis gas inlet pipeline (101); the temperature detection device (401) is installed on the synthesis gas outlet pipeline (102).

2. A hydrogen carrier self-thermal synthesis system according to claim 1, wherein, It further comprises a first regulating valve (402), which is arranged in parallel with the 1# heat exchanger (200), and the two ends of the first regulating valve (402) are respectively connected with the pipelines on both sides of the 1# heat exchanger (200).

3. A hydrogen carrier autothermal synthesis system according to claim 1 or 2, wherein It further comprises a second regulating valve (403), which is arranged in parallel with the 2# heat exchanger (300), and the two ends of the second regulating valve (403) are respectively connected with the synthesis gas inlet pipeline (101) and the synthesis gas outlet pipeline (102) through pipelines.

4. A hydrogen carrier self-thermal synthesis system according to claim 3, wherein, The synthesis gas passes through the flow detection device (400) and then is divided into two streams through the second regulating valve (403) and the 2# heat exchanger (300).

5. A hydrogen carrier autothermal synthesis system according to claim 4, wherein It further comprises a control device (500) for collecting the temperature detection results of the temperature detection device (401) and the flow detection results of the flow detection device (400), and adjusting the opening of the first regulating valve (402) or the second regulating valve (403) according to the temperature detection results of the temperature detection device (401) and the flow detection results of the flow detection device (400).

6. A hydrogen carrier self-thermal synthesis system according to claim 4, wherein, The hydrogen carrier compound preparation device (100) is at least one of an ammonia synthesis reaction device and a methanol synthesis reaction device.

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