Energy recovery device for raw material gas storage and feeding in production of ammonia-alcohol product from green hydrogen

Abstract

The utility model discloses a feed gas storage and feeding energy recovery device for producing an ammonia-alcohol product by green hydrogen, which comprises a gas storage system, an outlet end of the gas storage system is further connected with an expansion system, and an outlet end of the expansion system is further sequentially connected with a pipeline mixer and a synthesis gas compressor; the expansion system comprises a high-pressure expansion unit and a low-pressure expansion unit; the expansion system further comprises a bypass pressure reducing valve, the expansion system is additionally arranged at the position of an outlet header pipe of the gas storage system, and gas in the high-pressure hydrogen gas storage tank is supplied to the downstream synthesis gas compressor according to different pressures in the high-pressure hydrogen gas storage tank at the moment in the process of supplying the gas to the downstream synthesis gas compressor. After valve outlet pressure is regulated and stabilized through a first pressure reducing valve or a second pressure reducing valve of different pressure grades, a high-pressure expansion machine or a low-pressure expansion machine of a corresponding outlet pressure grade drives a generator to do work, and gas pressure energy is converted into kinetic energy output by an expansion system. The generator can be driven to output energy so as to recycle pressure energy of stored gas, and energy loss is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of raw gas energy recovery, and in particular to an energy recovery device for storing and feeding raw gas for producing ammonia alcohol products using green hydrogen. Background Art

[0002] In recent years, due to the significant reduction in the cost of photovoltaic and wind power, coupled with the demand stimulation of carbon neutrality and the European energy crisis, the installed capacity has increased significantly. As of the end of April this year, my country's installed wind power capacity was 380 million kilowatts, and photovoltaic power generation capacity was 440 million kilowatts. The total installed capacity of wind power and photovoltaic power generation reached 820 million kilowatts, accounting for 30.9% of the country's installed power generation capacity, of which wind power accounted for 14.3% and photovoltaic power generation accounted for 16.6%.

[0003] Due to the instability of the output of the green power generation device, the electrolyzer that receives green power and produces hydrogen also has obvious instability. The conventional solution in the industry is to use a series of large high-pressure gas tanks to temporarily store hydrogen and provide a relatively stable supply of raw gas for the downstream. Since the pressure of hydrogen produced by the current electrolyzer equipment is generally only 2-3MPa, and the synthetic methanol needs to be achieved under a pressure environment of 6-9MPa, and the pressure of the synthetic ammonia needs to be achieved under a high-pressure environment of 8-15MPa, it is often necessary to equip the synthesis device with a synthesis gas compressor to increase the pressure of the synthetic raw gas with a low pressure in the gas tank to the pressure required for synthesis. In addition, in general, in order to make the best use of the effective gas in the high-pressure gas tank, a set of pressure reducing valves will be set at the outlet of the gas tank, and the valve opening will be adjusted according to the pressure change in the high-pressure gas tank, so that the pressure at the inlet of the compressor is as stable as possible, to prevent the pressure at the outlet of the compressor from fluctuating significantly, causing the synthesis gas compressor to surge or other unstable operation due to the inlet pressure fluctuation.

[0004] However, reducing pressure through valves will cause a significant loss of gas pressure, especially when the gas tank is full, at which time the hydrogen pressure out of the tank is relatively high. Due to the high cost of large high-pressure gas spherical tanks, if a large number of spherical tanks are configured in a project, the investment will increase significantly. Generally speaking, the effective volume in the high-pressure gas tank will be used as much as possible, and the valve outlet pressure is required to be as low as possible so that the gas stored in the high-pressure gas tank can be used as much as possible in production. By increasing the utilization rate of the effective gas stored in the gas tank, the required volume and number of high-pressure gas tanks can be reduced to reduce project investment expenses. However, in this way, most of the gas pressure energy stored in the high-pressure gas tank will be lost, and the low inlet pressure requires the synthesis gas compressor to consume more energy to complete the pressurization of the synthetic raw gas. In this way, the internal energy of the gas originally stored in the high-pressure gas tank will be wasted, resulting in an increase in the overall system energy consumption. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the utility model is to provide an energy recovery device for storing and feeding raw gas for producing ammonia products with green hydrogen, so as to solve the problem that the devices in the prior art easily cause significant loss of gas pressure and high overall energy consumption.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions to achieve the above problems: an energy recovery device for storing and feeding raw gas for producing ammonia alcohol products with green hydrogen, comprising a gas storage system, the outlet end of the gas storage system is also connected to an expansion system, and the outlet end of the expansion system is also connected to a pipeline mixer and a synthesis gas compressor in sequence;

[0007] The expansion system comprises a high-pressure expansion unit and a low-pressure expansion unit;

[0008] The high-pressure expansion unit comprises a first pressure reducing valve, a high-pressure expander and a first switch valve which are connected to each other; the low-pressure expansion unit comprises a second pressure reducing valve, a low-pressure expander and a second switch valve which are connected to each other;

[0009] The expansion system further comprises a bypass pressure reducing valve, one end of which is connected to the outlet end of the gas storage system, and the other end of which is connected to the pipeline mixer;

[0010] One end of the first pressure reducing valve is connected to the inlet end of the high-pressure expander, and the other end is connected to the outlet end of the gas storage system; one end of the second pressure reducing valve is connected to the inlet end of the low-pressure expander, and the other end is connected to the outlet end of the gas storage system; the high-pressure expander and the low-pressure expander are also respectively equipped with generators;

[0011] The pipeline mixer is also provided with a nitrogen inlet, and the pipeline mixer is used to mix the gas output from the gas storage system and the gas entering from the nitrogen inlet.

[0012] The utility model also has the following technical features:

[0013] The gas storage system comprises a plurality of gas storage units;

[0014] The gas storage unit comprises a switch valve, a high-pressure hydrogen gas storage tank and a flow switch valve installed on a hydrogen supply branch pipe, one end of the hydrogen supply branch pipe is connected to the first hydrogen supply main pipe, and the other end is connected to the second hydrogen supply main pipe;

[0015] The first pressure reducing valve is installed on the first gas supply branch pipe, one end of the first gas supply branch pipe is connected to the second hydrogen supply main pipe, and the other end is connected to the inlet of the high-pressure expander, the outlet of the high-pressure expander is connected to the first branch pipe, the first branch pipe is connected to the pipeline mixer, and the first switch valve is installed on the first branch pipe;

[0016] The second pressure reducing valve is installed on the second gas supply branch pipe, one end of the second gas supply branch pipe is connected to the second hydrogen supply main pipe, and the other end is connected to the inlet of the low-pressure expander, the outlet of the low-pressure expander is connected to the second branch pipe, the second branch pipe is connected to the first branch pipe, and the second switch valve is installed on the second branch pipe;

[0017] The bypass pressure reducing valve is installed on the third gas supply branch pipe, one end of the third gas supply branch pipe is connected to the second hydrogen supply main pipe, and the other end is connected to the first branch pipe;

[0018] A nitrogen supply pipe is installed on the nitrogen inlet of the pipeline mixer, and a synthesis gas outlet pipeline is also connected to the outlet end of the synthesis gas compressor.

[0019] Compared with the prior art, the utility model has the following technical effects:

[0020] (I) The utility model provides an energy recovery device for storing and feeding raw gas for producing ammonia alcohol products using green hydrogen. By adding an expansion system to the outlet main pipe of the gas storage system, the gas in the high-pressure hydrogen storage tank is supplied to the downstream synthesis gas compressor. According to the different pressures in the high-pressure hydrogen storage tank at this time, the gas first passes through a first pressure reducing valve or a second pressure reducing valve of different pressure levels to adjust the outlet pressure to stabilize the pressure, and then drives the generator to work through a high-pressure expander or a low-pressure expander of the corresponding outlet pressure level, converting the gas pressure energy into kinetic energy output by the expansion system, which can drive the generator to output energy to recover the pressure energy of the stored gas and reduce energy loss.

[0021] (II) The energy recovery device for storing and feeding the raw gas for producing ammonia alcohol products provided by the utility model recovers the pressure energy of the gas in the tank as much as possible by using an expander. Since the expansion of the gas in the expander is close to an isentropic process, a large amount of the pressure energy of the gas itself will be consumed. Therefore, the temperature of the outlet gas after expansion is greatly reduced. Since the temperature of the hydrogen gas is significantly reduced, and the lower the gas temperature, the less power consumption the compressor requires, the synthesis gas compressor can save a certain amount of compression power consumption. More importantly, the gas expansion drives the generator to generate electricity, recovering part of the pressure energy in the gas, and achieving a certain degree of energy consumption reduction for the entire green hydrogen production of synthetic ammonia or methanol product device. In addition, this device plans to use two expanders with different inlet pressure levels but the same outlet pressure to reduce the difficulty of achieving stable pressure discharge of the expander by adjusting the outlet guide vanes alone.

[0022] (III) The energy recovery device for storing and feeding raw gas for producing ammonia alcohol products with green hydrogen provided by the utility model has a simple structure and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1This is a schematic diagram of the overall structure of the energy recovery device for storing and feeding raw gas for producing ammonia alcohol products using green hydrogen according to the utility model;

[0024] The meaning of each symbol in the accompanying drawings:

[0025] 1-gas storage system, 2-expansion system, 3-pipeline mixer, 4-syngas compressor, 5-hydrogen supply branch pipe, 6-first hydrogen supply main pipe, 7-second hydrogen supply main pipe, 8-first gas supply branch pipe, 9-first branch pipe, 10-second gas supply branch pipe, 11-second branch pipe, 12-third gas supply branch pipe, 13-nitrogen supply pipe, 14-syngas outlet pipeline;

[0026] 1-1 switch valve, 1-2 high pressure hydrogen gas storage tank, 1-3 flow switch valve;

[0027] 2-1 high pressure expansion unit, 2-2 low pressure expansion unit, 2-3 bypass pressure reducing valve;

[0028] 2-1-1 first pressure reducing valve, 2-1-2 high pressure expander, 2-1-3 first switch valve;

[0029] 2-2-1 second pressure reducing valve, 2-2-2 low-pressure expander, 2-2-3 second switch valve.

[0030] The specific contents of the utility model are further explained in detail below in conjunction with the embodiments. DETAILED DESCRIPTION

[0031] All components in the present invention, unless otherwise specified, are components known in the prior art.

[0032] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of the present application fall within the protection scope of the present invention.

[0033] Embodiment 1:

[0034] This embodiment provides an energy recovery device for storing and feeding raw gas for producing ammonia alcohol products using green hydrogen, such as Figure 1 As shown, it comprises a gas storage system 1, the outlet end of the gas storage system 1 is further connected to an expansion system 2, and the outlet end of the expansion system 2 is further connected to a pipeline mixer 3 and a synthesis gas compressor 4 in sequence;

[0035] The expansion system 2 includes a high-pressure expansion unit 2-1 and a low-pressure expansion unit 2-2; the high-pressure expansion unit 2-1 includes a first pressure reducing valve 2-1-1, a high-pressure expander 2-1-2 and a first switch valve 2-1-3 which are connected to each other;

[0036] The low-pressure expansion unit 2-2 includes a second pressure reducing valve 2-2-1, a low-pressure expander 2-2-2 and a second switch valve 2-2-3 which are connected to each other;

[0037] The expansion system 2 further comprises a bypass pressure reducing valve 2-3, one end of the bypass pressure reducing valve 2-3 is connected to the outlet end of the gas storage system 1, and the other end is connected to the pipeline mixer 3;

[0038] One end of the first pressure reducing valve 2-1-1 is connected to the inlet end of the high-pressure expander 2-1-2, and the other end is connected to the outlet end of the gas storage system 1; one end of the second pressure reducing valve 2-2-1 is connected to the inlet end of the low-pressure expander 2-2-2, and the other end is connected to the outlet end of the gas storage system 1; the high-pressure expander 2-1-2 and the low-pressure expander 2-2-2 are also equipped with generators respectively;

[0039] The pipeline mixer 3 is also provided with a nitrogen inlet, and the pipeline mixer 3 is used to mix the gas output from the gas storage system 1 and the gas entering through the nitrogen inlet.

[0040] By adding an expansion system 2 at the outlet of these gas storage systems 1, the gas in the gas storage system 1, when supplying gas to the downstream synthesis gas compressor 4, converts the gas pressure energy into kinetic energy output by the expander through the gas expander, which can drive the generator to output energy and reduce energy loss.

[0041] Generally speaking, in order to reduce the use of high-pressure hydrogen spherical tanks, green hydrogen projects will use the gas stored in the tanks as much as possible. For example, for a storage tank with a designed storage pressure of 3MPa, the inlet pressure of the synthesis gas compressor 4 may be set to 1MPa instead of 2MPa or 2.5MPa, because a lower inlet pressure will increase the energy consumption of the synthesis gas compressor. However, the effective volume in the high-pressure spherical tank can be used as much as possible to reduce equipment investment and floor space.

[0042] If the electrolyzer device does not work because there is no green electricity supply in the upstream due to the low wind period or long-term rainy days, then the pressure inside the gas tank will gradually decrease during the process of gas supply from the gas tank to the downstream. In order to make the best use of the pressure energy of the gas, we can set one or more gas expanders at the outlet of the gas tank according to the maximum gas storage pressure of the gas tank. For example, if the storage pressure of the storage tank is designed to be 3MPa, two expanders with inlet pressures of 2.4MPa and 1.8MPa respectively can be set, and the gas expander only drives the generator, not other dynamic equipment such as pumps or compressors. After the gas does work externally through the expander, the pressure energy is converted into kinetic energy, which drives the generator to generate electricity. Before the pressure in the tank drops below 2.4MPa, the opening of the inlet pressure control valve of the 2.4MPa gas expander is adjusted to allow the gas to be sent to the gas expander to do work at a pressure of 2.4MPa after the pressure control valve. The expanded gas is sent out of the expander at a pressure of about 1.0MP. At this stage, the output power of the 2.4MPa gas expander is basically stable. When the pressure in the tank drops to 2.4MPa, the inlet pressure control valve of the 1.8MPa expander is opened and gas is started. At this time, the 1.8MPa hydrogen expander is started to drive the expander to drive the generator to generate electricity, and then the inlet valve of the 2.4MPa expander is closed. When the gas tank pressure gradually falls below 1.8MPa, the bypass pressure control valve can be opened and the 1.8MPa-level gas expander can be shut down. The gas is sent downstream through the bypass pressure control valve. This device setting allows the gas to fully utilize the internal energy of the gas in the gas expander and recover the gas pressure energy in the high-pressure gas storage tank as much as possible, thereby improving the energy utilization rate of the hydrogen storage and feeding system and reducing the overall energy consumption level of the green hydrogen to green ammonia and green alcohol units.

[0043] As a preferred embodiment of this invention:

[0044] The gas storage system 1 comprises a plurality of gas storage units;

[0045] The gas storage unit comprises a switch valve 1-1, a high-pressure hydrogen storage tank 1-2 and a flow switch valve 1-3 installed on a hydrogen supply branch pipe 5. One end of the hydrogen supply branch pipe 5 is connected to a first hydrogen supply main pipe 6, and the other end is connected to a second hydrogen supply main pipe 7.

[0046] The first hydrogen supply main pipe 6 receives hydrogen from the electrolytic cell group after gas-liquid separation and TSA drying;

[0047] The general type of high-pressure hydrogen storage tank 1-2 is a high-pressure gas spherical tank. When the tank is normally full, the gas storage pressure is generally 2.5-3MPa, and the volume can be 1000-3000m 3, or even larger. The specific size can be determined according to the designed hydrogen storage capacity of the project. If it is a project with a particularly large hydrogen storage capacity (≥100t), then it is possible to consider increasing the storage pressure of the high-pressure gas spherical tank to 4-5MPa, and use a gas storage compressor to pressurize the raw gas from the electrolyzer and then send it to the gas tank for storage, so as to reduce the number of high-pressure spherical tanks and investment. This plan is based on existing projects, and the configuration of using a compressor to boost the pressure and then send the gas tank is not considered here and below.

[0048] Among them, the number of high-pressure gas spherical tanks, generally speaking, a project requires more than one high-pressure gas spherical tank, and large-scale green hydrogen projects require multiple or even dozens of them. Each high-pressure gas spherical tank can be isolated from each other by valves, or several can be interconnected by pipelines. As a separate group, the intake and exhaust of the gas are controlled by the valves on the inlet and outlet mains of each tank group. In order to keep the description simple in this article and the following text, the following scheme only introduces how to set up the system and system structure when two high-pressure gas spherical tanks are needed in the project, such as Figure 1 But in fact, it can be increased to 3, 4, ..., N, and what needs to be added are only the branch pipes on the main pipe and the related isolation valves.

[0049] The on-off valve (XV valve) and flow on-off valve (HV) on the pipeline are common type valves with no special requirements, and the pressure drop when the manual control valve is normally opened is as low as possible.

[0050] The function of the gas expander is to expand the high-pressure hydrogen gas outward, which is similar to adiabatic isentropic expansion, and drives the impeller to do work. The impeller drives the generator to output electrical energy. Since it drives the generator, according to the experience of use, even if the inlet pressure is significantly reduced, the expander can still continue to work, but the output power of the generator will decrease with the reduction of the inlet pressure. When the power generation power drops below 30-40% of the design power, it can be considered that the gas no longer passes through the high-pressure expansion unit 2-1 and the low-pressure expansion unit 2-2, and enters the synthesis gas compressor 4 after throttling by the bypass pressure reducing valve 2-3. Since the energy output by the generator is intermittent and the power will change significantly, it is recommended to equip the generator with a small electrochemical energy storage device to stabilize the final power output. At present, manufacturers with large and medium-sized hydrogen expander performance include Atlas and other manufacturers.

[0051] If hydrogen is used to produce synthetic ammonia, industrial pure nitrogen is produced by an air separation nitrogen generator and sent to the inlet of the pipeline mixer 3 as a part of the raw gas for ammonia synthesis, and then mixed with hydrogen and enter the synthesis gas compressor 4; if it is used to synthesize green methanol, carbon dioxide is used as a part of the raw gas and sent to the inlet of the pipeline mixer 3.

[0052] As a preferred embodiment of this invention:

[0053] The first pressure reducing valve 2-1-1 is installed on the first gas supply branch pipe 8, one end of the first gas supply branch pipe 8 is connected to the second hydrogen supply main pipe 7, and the other end is connected to the inlet of the high-pressure expander 2-1-2, the outlet of the high-pressure expander 2-1-2 is connected to the first branch pipe 9, the first branch pipe 9 is connected to the pipeline mixer 3, and the first switch valve 2-1-3 is installed on the first branch pipe 9;

[0054] The second pressure reducing valve 2-2-1 is installed on the second gas supply branch pipe 10, one end of the second gas supply branch pipe 10 is connected to the second hydrogen supply main pipe 7, and the other end is connected to the inlet of the low-pressure expander 2-2-2, the outlet of the low-pressure expander 2-2-2 is connected to the second branch pipe 11, the second branch pipe 11 is connected to the first branch pipe 9, and the second switch valve 2-2-3 is installed on the second branch pipe 11;

[0055] The bypass pressure reducing valve 2-3 is installed on the third gas supply branch pipe 12, one end of the third gas supply branch pipe 12 is connected to the second hydrogen supply main pipe 7, and the other end is connected to the first branch pipe 9;

[0056] As a preferred embodiment of this invention:

[0057] A nitrogen supply pipe 13 is installed on the nitrogen inlet of the pipeline mixer 3, and a synthesis gas outlet pipeline 14 is also connected to the outlet end of the synthesis gas compressor 4. The synthesis gas is sent to the next process through the synthesis gas outlet pipeline 14.

[0058] The specific working process of this embodiment is as follows:

[0059] 1. After hydrogen comes out of the high-pressure gas storage tank, according to the different pressures in the tank at this time, it first passes through the regulating valves of different pressure levels to adjust the outlet pressure to stabilize the pressure, and then drives the generator to work through the gas expander of the corresponding outlet pressure level to recover the pressure energy of the stored gas. In order to ensure that the expander can work stably and recover the pressure energy of the gas in the tank as much as possible, two or more stages of gas expanders with different rated inlet pressures can be set. This can ensure that the gas expander in the high-pressure section can work relatively normally, and also ensure that when the pressure of the gas tank drops significantly, the remaining gas with lower pressure can continue to recover the pressure energy through the low-pressure gas expander. This setting not only achieves the goal of recovering the pressure energy of the gas in the tank, but also achieves the purpose of graded utilization of pressure energy.

[0060] The specific control logic of the graded utilization of pressure energy is exemplified as follows: Assuming that the normal pressure of the high-pressure hydrogen gas storage tank 1-2 is 3.0 MPa, a pressure interlock control signal is set on the high-pressure hydrogen gas storage tank 1-2 to control the first pressure reducing valve 2-1-1 and the second pressure reducing valve 2-2-1 respectively;

[0061] When the pressure in the tank is greater than or equal to 2.4MPa, open the first pressure reducing valve 2-1-1 to stabilize the pressure after the valve at 2.4MPa, and the gas enters the high-pressure gas expander 2-1-2 to perform work and drive the generator to generate electricity;

[0062] When the pressure in the tank is less than 2.4MPa, close the first pressure reducing valve 2-1-1, open the second pressure reducing valve 2-2-1, stabilize the pressure after the valve at 1.8MPa, and the gas enters the low-pressure gas expansion machine 2-2-2 to do work, while driving the generator to generate electricity;

[0063] When the pressure in the tank is less than 1.8MPa, close the second pressure reducing valve 2-2-1 and open the bypass pressure reducing valve 2-3; the hydrogen pressure after the high-pressure gas expander, the low-pressure gas expander and the bypass pressure reducing valve is 1.0MPa and is sent to the downstream device.

[0064] The conventional method of hydrogen output from the high-pressure hydrogen storage tank 1-2 is generally to use a pressure reducing valve to reduce pressure, while the present invention mainly uses a two-stage gas expander high-pressure expansion unit 2-1 and a low-pressure expansion unit 2-2 to reduce pressure. The two methods have different principles and energy utilization:

[0065] (1) The working principle of the pressure reducing valve is to reduce the inlet pressure to a certain required outlet pressure through adjustment, and rely on the energy of the medium itself to automatically keep the outlet pressure stable. The pressure reducing valve is a throttling element with variable local resistance. In order to achieve the purpose of pressure reduction, the throttling area is changed to change the flow rate and the kinetic energy of the fluid, resulting in different pressure losses. That is, in the above example, the pressure energy between 3.0MPa and 1.0MPa is lost.

[0066] (2) The principle of the gas expander is to utilize the gas in the expander to perform adiabatic expansion to consume the internal energy of the gas itself, thereby significantly reducing the pressure and temperature of the gas. In the present invention, the high-pressure gas expander fully utilizes the pressure energy between 2.4MPa and 1.0MPa, with an adiabatic efficiency of 65-85%; the low-pressure gas expander fully utilizes the pressure energy between 1.8MPa and 1.0MPa, with an adiabatic efficiency of 60-70%. Therefore, the temperature of the outlet gas after expansion is greatly reduced. Since the temperature of the hydrogen is significantly reduced, the lower the gas temperature, the less power consumption is required by the downstream synthesis gas compressor. Therefore, the synthesis gas compressor can save a certain amount of compression power consumption.

[0067] 2. The present invention also sets a bypass secondary line, and sets a bypass pressure reducing valve 2-3 on the secondary line as a backup regulating means of the system. Under normal working conditions, the bypass pressure reducing valve 2-3 is in a closed state; under abnormal working conditions, the bypass pressure reducing valve 2-3 is opened. Abnormal working conditions include:

[0068] (1) The high-pressure and low-pressure gas expanders fail to function;

[0069] (2) When the pressure in the high-pressure gas storage tank is low, in the above example, the pressure is less than 1.8 MPa. Both abnormal conditions will immediately interlock and open the bypass pressure reducing valve 2-3 on the secondary line to transport hydrogen to the downstream synthesis gas compressor 4, achieving continuous and stable gas supply.

[0070] This paper takes a wind-solar green hydrogen production project with an annual output of 160,000 tons of synthetic ammonia as an example. The project plans to design the electrolyzer to produce 60,000 Nm of hydrogen when the electrolytic cell is 100% loaded with water electrolysis. 3 / h, the designed annual operating time of the synthetic ammonia unit is 8000 hours, and the effective liquid ammonia product is expected to be 159,800 tons / year. The average operating load of the synthetic ammonia unit is about 67.6%. According to the effective capacity of the hydrogen storage tank, which is set to meet the minimum 25% load of synthetic ammonia for 36 hours, the required storage capacity of hydrogen is about 49,000kg, of which the outlet pressure of the electrolyzer is 3MPa, the design pressure of the hydrogen storage tank is 3MPa, and the hydrogen release pressure is 1MPa.

[0071] If the conventional design is adopted, the hydrogen in the spherical tank is released and mixed with the nitrogen from the air separation unit, and then sent to the synthesis gas compressor. The synthesis gas compressor increases the pressure to 14MPa and then sends it to the ammonia synthesis reactor to produce ammonia products. According to calculations, the power consumption of the compressor and pump and other electrical equipment (excluding the power consumption of the electrolyzer) under 100% synthesis load is 24290kw, and the fresh water consumption is 229t / h; the total power consumption of electrical equipment is expected to be 1.315×10 8 KWH, fresh water consumption is 1.24×10 6 t.

[0072] If the contents of the present invention are adopted, two hydrogen expanders with inlet pressures of 2.4MPa and 1.8MPa, as well as corresponding generators and an energy storage system of about 1 hour are added behind the hydrogen spherical tank to make full use of the gas pressure energy in the gas tank. After analyzing the power generation time distribution of the wind and photovoltaic power generation device and the gas tank storage capacity, it is estimated that the gas tank pressure will remain above 2.4MPa for about 28% of the time, the pressure range between 1.8 and 2.4MPa for 43%, and the gas pressure in the gas tank is expected to be lower than 1.8MPa for the rest of the time. The hydrogen in the spherical tank is released and mixed with the nitrogen from the air separation unit and sent to the combined The synthesis gas compressor increases the pressure to 14MPa and then feeds it into the ammonia synthesis reactor to produce ammonia products. The device includes a trap device including an air separation nitrogen generator. The power consumption of the compressor and pump and other electrical equipment (excluding the power consumption of the electrolyzer) under 100% synthesis load is 24264kw, and the fresh water consumption is 226.5t / h. At the same time, the high-pressure / low-pressure hydrogen expander can drive the generator to output 452kw of power generation. Compared with the conventional setting, the present invention can save equivalent energy consumption of (24290-24264+452)=478kw at 100% synthesis load; the total power consumption of electrical equipment throughout the year is expected to be 1.312×

[0073] 10 8 KWH, fresh water consumption is 1.225×10 6 t, and the expander drives the generator to generate 2.44×10 6 KWH, according to this scale of high and low pressure gas expanders and supporting generators and 500kwh energy storage system, it is estimated that the additional investment will be 2.2 to 2.5 million. According to the domestic average electricity price of about 0.4 yuan / kwh, the present invention can save energy consumption expenditure data of about 1.03 million / year. The estimated additional investment of the project is about 2.2 to 2.5 years for the investment recovery period of the project.

[0074] The above technical solutions are only preferred specific implementation methods of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be thought of by any technician familiar with the field within the technical scope disclosed by the present utility model without creative work are all covered within the protection scope of the present utility model.

Claims

1. An energy recovery device for storing and feeding raw gas for producing ammonia alcohol products using green hydrogen, comprising a gas storage system (1), characterized in that: The outlet end of the gas storage system (1) is also connected to an expansion system (2), and the outlet end of the expansion system (2) is also connected in sequence to a pipeline mixer (3) and a synthesis gas compressor (4); The expansion system (2) comprises a high-pressure expansion unit (2-1) and a low-pressure expansion unit (2-2); The high-pressure expansion unit (2-1) comprises a first pressure reducing valve (2-1-1), a high-pressure expander (2-1-2) and a first switch valve (2-1-3) which are connected to each other; The low-pressure expansion unit (2-2) comprises a second pressure reducing valve (2-2-1), a low-pressure expansion machine (2-2-2) and a second switch valve (2-2-3) which are connected to each other; The expansion system (2) further comprises a bypass pressure reducing valve (2-3), one end of the bypass pressure reducing valve (2-3) being connected to the outlet end of the gas storage system (1), and the other end of the bypass pressure reducing valve (2-3) being connected to the pipeline mixer (3); One end of the first pressure reducing valve (2-1-1) is connected to the inlet end of the high-pressure expansion machine (2-1-2), and the other end is connected to the outlet end of the gas storage system (1); one end of the second pressure reducing valve (2-2-1) is connected to the inlet end of the low-pressure expansion machine (2-2-2), and the other end is connected to the outlet end of the gas storage system (1); the high-pressure expansion machine (2-1-2) and the low-pressure expansion machine (2-2-2) are also respectively equipped with generators; The pipeline mixer (3) is also provided with a nitrogen inlet, and the pipeline mixer (3) is used to mix the gas output from the gas storage system (1) and the gas entering through the nitrogen inlet.

2. The energy recovery device for storing and feeding raw gas for producing ammonia alcohol products using green hydrogen as claimed in claim 1, characterized in that: The gas storage system (1) comprises a plurality of gas storage units; The gas storage unit comprises a switch valve (1-1), a high-pressure hydrogen storage tank (1-2) and a flow switch valve (1-3) installed on a hydrogen supply branch pipe (5); one end of the hydrogen supply branch pipe (5) is connected to a first hydrogen supply main pipe (6), and the other end is connected to a second hydrogen supply main pipe (7).

3. The energy recovery device for storing and feeding raw gas for producing ammonia alcohol products using green hydrogen as claimed in claim 2, characterized in that: The first pressure reducing valve (2-1-1) is installed on the first gas supply branch pipe (8), one end of the first gas supply branch pipe (8) is connected to the second hydrogen supply main pipe (7), and the other end is connected to the inlet of the high-pressure expander (2-1-2), the outlet of the high-pressure expander (2-1-2) is connected to the first branch pipe (9), the first branch pipe (9) is connected to the pipeline mixer (3), and the first switch valve (2-1-3) is installed on the first branch pipe (9); The second pressure reducing valve (2-2-1) is installed on the second gas supply branch pipe (10), one end of the second gas supply branch pipe (10) is connected to the second hydrogen supply main pipe (7), and the other end is connected to the inlet of the low-pressure expander (2-2-2), the outlet of the low-pressure expander (2-2-2) is connected to the second branch pipe (11), the second branch pipe (11) is connected to the first branch pipe (9), and the second switch valve (2-2-3) is installed on the second branch pipe (11); The bypass pressure reducing valve (2-3) is installed on the third gas supply branch pipe (12), one end of the third gas supply branch pipe (12) is connected to the second hydrogen supply main pipe (7), and the other end is connected to the first branch pipe (9).

4. The energy recovery device for storing and feeding raw gas for producing ammonia alcohol products using green hydrogen as claimed in claim 1, characterized in that: A nitrogen supply pipe (13) is installed on the nitrogen inlet of the pipeline mixer (3), and a synthesis gas outlet pipeline (14) is also connected to the outlet end of the synthesis gas compressor (4).

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