CN109269224B - Ammonia refrigeration system - Google Patents
Ammonia refrigeration system Download PDFInfo
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- CN109269224B CN109269224B CN201811068049.5A CN201811068049A CN109269224B CN 109269224 B CN109269224 B CN 109269224B CN 201811068049 A CN201811068049 A CN 201811068049A CN 109269224 B CN109269224 B CN 109269224B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/08—Separating gaseous impurities from gases or gaseous mixtures or from liquefied gases or liquefied gaseous mixtures
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/02—Preparation, purification or separation of ammonia
- C01C1/04—Preparation of ammonia by synthesis in the gas phase
- C01C1/0405—Preparation of ammonia by synthesis in the gas phase from N2 and H2 in presence of a catalyst
- C01C1/0482—Process control; Start-up or cooling-down procedures
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2210/00—Processes characterised by the type or other details of the feed stream
- F25J2210/20—H2/N2 mixture, i.e. synthesis gas for or purge gas from ammonia synthesis
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- Automation & Control Theory (AREA)
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Abstract
The invention discloses an ammonia refrigeration system, comprising: the ammonia cooling device comprises a liquid ammonia storage tank, a first ammonia cooler, a second ammonia cooler, a first ammonia separator, a second ammonia separator, an ammonia compressor, an ammonia condenser and an ammonia cooling pump, wherein the shell pass of the first ammonia cooler is used for receiving liquid ammonia in the liquid ammonia storage tank, the tube pass of the first ammonia cooler is used for receiving synthesis gas from an ammonia synthesis tower, gas ammonia generated by the first ammonia cooler enters the ammonia compressor, and the synthesis gas cooled by the first ammonia cooler enters the first ammonia separator. The system provided by the invention can ensure the normal operation of the cold ammonia pump, prevent the surge of the ammonia compressor, avoid the trip of the ammonia compressor and ensure the safe and stable operation of the ammonia refrigeration system.
Description
Technical Field
The invention belongs to the technical field of synthetic ammonia devices, and particularly relates to an ammonia refrigeration system in a synthetic ammonia production process.
Background
The technological process of producing synthetic ammonia with the tail gas from acetylene production with partial natural gas oxidation process as material includes the following steps: desulfurizing and gas making, medium-low temperature transformation and methanation, a decarburization process, a compression process, ammonia synthesis and purge gas recovery, ammonia freezing and liquid ammonia storage. The ammonia refrigeration is one of the most important processes in the production process of synthetic ammonia and one of the most widely used processes, has the function of further reducing the temperature of the synthesis gas from the ammonia synthesis tower, and separates the ammonia from the hydrogen and the nitrogen in the synthesis gas, and mainly comprises an ammonia cooler, an ammonia separator, an ammonia compressor, an ammonia condenser, a liquid ammonia storage tank and a cold ammonia pump.
Liquid ammonia in a second ammonia cooler in the existing ammonia freezing system is conveyed to a liquid ammonia storage tank through an ammonia cooling pump so as to be used in the subsequent urea production and liquid ammonia spherical tanks. The cold ammonia pump is as the equipment of carrying liquid ammonia, and the content requirement to gas in the transport medium is very high, in case liquid ammonia takes gas and will take place the gas and tie the phenomenon, leads to the unable liquid ammonia of sending out in the second ammonia cooler, and ammonia refrigeration system technology is undulant, and then makes the ammonia compressor trip, so advance the content control of gas-phase component in the liquid ammonia before the cold ammonia pump and be particularly important to ammonia refrigeration system's normal operating.
Meanwhile, the raw material of the synthetic ammonia is tail gas generated in acetylene production by an upstream natural gas partial oxidation method, so that the load of the synthetic ammonia device is greatly influenced by the acetylene device, and the acetylene device is frequently in a low-load state for a long time due to the particularity of the process, so that the acetylene device is in low-load operation for a long time, and the normal operation of an ammonia refrigeration system is also limited; under the condition of low load, on one hand, liquid ammonia generated in the synthesis gas is reduced, on the other hand, the heat carried by gas ammonia is reduced, so that the amount of liquid ammonia in an ammonia refrigeration system is reduced, an ammonia cooler and an ammonia separator cannot keep normal liquid levels, a gas-phase system of the ammonia cooler has the condition of gas carrying liquid, a liquid-phase system has the condition of liquid carrying gas, and once the gas carrying liquid of an ammonia compressor serving as equipment for compressing gas is carried by the gas, the impeller of the compressor is damaged, so that the ammonia compressor frequently jumps; the cold ammonia pump is used as a liquid conveying device, and the liquid with gas enters the device to generate a gas binding phenomenon.
Disclosure of Invention
Aiming at the technical defect, the invention solves the technical problems that the cold ammonia pump is easy to generate air binding and the ammonia compressor frequently jumps in the existing ammonia refrigeration system by additionally arranging the gas-liquid separator between the second ammonia separator and the cold ammonia pump, additionally arranging the anti-surge line between the ammonia condenser and the first ammonia cooler and the second ammonia cooler and adopting the method of remote control of the information acquisition control system. The invention provides the following technical scheme:
according to one aspect of the present invention, there is provided an ammonia refrigeration system comprising: the ammonia cooling system comprises a liquid ammonia storage tank, a first ammonia cooler, a second ammonia cooler, a first ammonia separator, a second ammonia separator, an ammonia compressor, an ammonia condenser and an ammonia cooling pump, wherein the shell pass of the first ammonia cooler is used for receiving liquid ammonia in the liquid ammonia storage tank, the tube pass of the first ammonia cooler is used for receiving synthesis gas from an ammonia synthesis tower, gas ammonia generated by the first ammonia cooler enters the ammonia compressor, and the synthesis gas cooled by the first ammonia cooler enters the first ammonia separator; the first ammonia separator is used for carrying out gas-liquid separation on the cooled synthesis gas to obtain primary gas and liquid ammonia; the shell side of the second ammonia cooler is used for receiving liquid ammonia of the first ammonia cooler, the tube side of the second ammonia cooler is used for receiving primary gas of the first ammonia separator, gas ammonia generated by the second ammonia cooler enters the ammonia compressor, and the primary gas cooled by the second ammonia cooler enters the second ammonia separator; the second ammonia separator is used for carrying out gas-liquid separation on the cooled primary gas to obtain secondary gas and liquid ammonia; the ammonia condenser is used for condensing the gas ammonia compressed by the ammonia compressor to obtain condensed liquid ammonia, and enabling the condensed liquid ammonia to automatically flow to the liquid ammonia storage tank; the cold ammonia pump is used for conveying the liquid ammonia of the second ammonia cooler to the liquid ammonia storage tank.
According to one embodiment of the invention, the ammonia gas cooling device further comprises a gas-liquid separator, the gas-liquid separator is arranged between the second ammonia cooler and the cold ammonia pump and used for performing gas-liquid separation on the liquid ammonia of the second ammonia cooler, and the liquid ammonia separated by the gas-liquid separator is conveyed to the liquid ammonia storage tank by the cold ammonia pump.
According to an embodiment of the present invention, it further comprises a liquid ammonia flash tank for subjecting the liquid ammonia separated by the first and second ammonia separators to low-pressure flash distillation, and delivering the flash-distilled liquid ammonia to the first ammonia cooler through a flash tank outlet line.
According to an embodiment of the invention, a first control valve is arranged on the flash evaporation outlet pipeline, and the first control valve is used for controlling the output of liquid ammonia after flash evaporation.
According to an embodiment of the invention, a liquid level indicator is arranged in the liquid ammonia flash tank.
According to an embodiment of the present invention, a first surge preventing line is provided between the ammonia condenser and the first ammonia cooler, and a first surge preventing valve is installed on the first surge preventing line; and a second anti-surge line is arranged between the ammonia condenser and the second ammonia cooler, and a second anti-surge valve is installed on the second anti-surge line.
According to one embodiment of the invention, the first anti-surge valve is installed at a position close to the inlet of the shell side of the first ammonia cooler, and the second anti-surge valve is installed at a position close to the inlet of the shell side of the second ammonia cooler.
According to one embodiment of the invention, the shell side outlet of the first ammonia cooler is connected with the two-stage inlet of the ammonia compressor through a first air outlet pipe, and a first outlet pressure regulating valve is mounted on the first air outlet pipe and used for regulating the pressure of the shell side of the first ammonia cooler; and the shell pass outlet of the second ammonia cooler is connected with one section of inlet of the ammonia compressor through a second air outlet pipe, and a second outlet pressure regulating valve is arranged on the second air outlet pipe and used for regulating the pressure of the shell pass of the second ammonia cooler.
According to one embodiment of the invention, the pressure of the first ammonia cooler shell side is greater than the pressure of the second ammonia cooler shell side.
According to one embodiment of the invention, the ammonia refrigeration system further comprises an information acquisition control system, wherein the information acquisition control system is respectively connected with the liquid level indicator and the valve and is used for receiving and processing signals transmitted by the liquid level indicator and controlling the opening of the valve in the ammonia refrigeration system.
Compared with the prior art, the ammonia refrigeration system provided by the invention has the following advantages: a gas-liquid separator is additionally arranged between the second ammonia separator and the cold ammonia pump, and the gas-phase components in the liquid ammonia are reduced by further separating the liquid ammonia in the second ammonia cooler, so that the normal operation of the cold ammonia pump is ensured; anti-surge lines are respectively additionally arranged between the ammonia condenser and the first ammonia cooler and between the ammonia condenser and the second ammonia cooler, so that gas ammonia in the ammonia condenser enters the ammonia compressor after passing through the first ammonia cooler and the second ammonia cooler, the ammonia compressor is prevented from surging, and the ammonia compressor is prevented from jumping; and the valve opening of the ammonia refrigeration system is remotely controlled by an information acquisition control system, so that the safe and stable operation of the ammonia refrigeration system is ensured.
Drawings
FIG. 1 is a process flow diagram of an ammonia refrigeration system provided by the present invention.
FIG. 2 is a process flow diagram of an ammonia refrigeration system provided with a gas-liquid separator and a liquid ammonia flash tank according to the present invention.
Detailed Description
In the following detailed description of the preferred embodiments of the invention, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, specific features of the invention, such that the advantages and features of the invention may be more readily understood and appreciated. The following description is an embodiment of the claimed invention, and other embodiments related to the claims not specifically described also fall within the scope of the claims. The present invention will be described in detail with reference to specific examples.
Fig. 1 shows a process flow diagram of an ammonia refrigeration system according to the present invention, in which the dotted line indicates the flow direction of the synthesis gas and the gaseous ammonia, and the solid line indicates the flow direction of the liquid ammonia.
As shown in fig. 1, the present invention provides an ammonia refrigeration system comprising: a liquid ammonia storage tank 1, a first ammonia cooler 2, a second ammonia cooler 3, a first ammonia separator 4, a second ammonia separator 5, an ammonia compressor 6, an ammonia condenser 7 and a cold ammonia pump 8, wherein the shell side of the first ammonia cooler 2 is used for receiving liquid ammonia in the liquid ammonia storage tank 1, the tube side of the first ammonia cooler 2 is used for receiving synthesis gas from an ammonia synthesis tower, gas ammonia generated by the first ammonia cooler 2 enters the ammonia compressor 6, and the synthesis gas cooled by the first ammonia cooler 2 enters the first ammonia separator 4; the first ammonia separator 4 is used for carrying out gas-liquid separation on the cooled synthesis gas to obtain primary gas and liquid ammonia; the shell side of the second ammonia cooler 3 is used for receiving the liquid ammonia of the first ammonia cooler 2, the tube side of the second ammonia cooler 3 is used for receiving the primary gas of the first ammonia separator 4, the gas ammonia generated by the second ammonia cooler 3 enters the ammonia compressor 6, and the primary gas cooled by the second ammonia cooler 3 enters the second ammonia separator 3; the second ammonia separator 5 is used for carrying out gas-liquid separation on the cooled primary gas to obtain secondary gas and liquid ammonia; the ammonia condenser 7 is used for condensing the gas ammonia compressed by the ammonia compressor 6 to obtain condensed liquid ammonia, and enabling the condensed liquid ammonia to automatically flow to the liquid ammonia storage tank 1; the cold ammonia pump 8 is used for delivering the liquid ammonia of the second ammonia cooler 3 to the liquid ammonia storage tank 1.
In the process of ammonia synthesis reaction, only a small part of hydrogen and nitrogen synthesizes gas ammonia under the action of a catalyst, so an ammonia refrigeration system is arranged for separating the gas ammonia from the hydrogen and the nitrogen from an ammonia synthesis tower. The temperature of the synthesis gas is reduced to the condensation temperature of the gaseous ammonia in an ammonia cooler, and the gaseous ammonia is separated from H in an ammonia separator2、N2And (4) separating.
And the synthetic gas from the ammonia synthesis tower enters a first ammonia cooler 2 for cooling and then enters a first ammonia separator 4 for gas-liquid separation of the cooled synthetic gas. The separated primary gas is further cooled in a second ammonia cooler 3, the gas is cooled to-6 ℃, and then the gas enters a second ammonia separator 5, and the cooled primary gas is further subjected to gas-liquid separation. And finally obtaining a secondary gas ammonia removal recovery system.
The first ammonia cooler 2 and the second ammonia cooler 3 are used for cooling the synthesis gas from the ammonia synthesis tower, and the two ammonia coolers are arranged for further reducing the temperature of the synthesis gas so as to better separate ammonia gas from hydrogen and nitrogen gas in the synthesis gas. The shell pass of the first ammonia cooler 2 and the shell pass of the second ammonia cooler 3 are liquid ammonia, the liquid ammonia is used as a refrigerant, the tube pass is synthesis gas, after the heat exchange is carried out between the liquid ammonia and the synthesis gas, gas ammonia in the synthesis gas is cooled into liquid ammonia, and the liquid ammonia in the shell pass is vaporized into gas ammonia.
The first ammonia separator 4 and the second ammonia separator 5 are both vertical containers, the gas outlet is provided with a large-scale defoaming plate and an anti-vortex plate for removing ammonia droplets in gas, a liquid level interlock is arranged at the anti-vortex plate, and the inlet is provided with a distributor. The two ammonia separators are used for separating ammonia and gas, and are arranged for more completely separating ammonia in the synthesis gas.
The ammonia condenser 7 has a shell pass of compressed gas ammonia and a tube pass of cooling medium water.
Fig. 2 shows a process flow diagram of an ammonia refrigeration system provided with a gas-liquid separator and a liquid ammonia flash tank according to the present invention, in which the dotted line indicates the flow direction of synthesis gas and gaseous ammonia, and the solid line indicates the flow direction of liquid ammonia.
As shown in fig. 2, the ammonia refrigeration system further includes a gas-liquid separator 9, where the gas-liquid separator 9 is installed between the second ammonia cooler 3 and the cold ammonia pump 8, and is configured to perform gas-liquid separation on the liquid ammonia in the second ammonia cooler 3, and the liquid ammonia separated by the gas-liquid separator 9 is transported to the liquid ammonia storage tank 1 by the cold ammonia pump 8. Meanwhile, the gas separated by the gas-liquid separator 9 enters the ammonia compressor 6. Under the condition of low load, the ammonia cooler and the ammonia separator cannot reach normal saturated partial pressure, and the ammonia separator cannot keep normal liquid level, so that the liquid ammonia which is sent to the ammonia pump 8 by the second ammonia cooler 3 is provided with a certain amount of gas ammonia, therefore, a gas-liquid separator 9 is arranged in front of the ammonia pump 8, the liquid ammonia and the gas ammonia of the second ammonia cooler 3 are separated completely, and the normal operation of the ammonia pump is ensured.
The ammonia freezing system provided by the invention further comprises a liquid ammonia flash tank 10, wherein the liquid ammonia flash tank 10 is used for carrying out low-pressure flash evaporation on the liquid ammonia separated by the first ammonia separator 4 and the second ammonia separator 5, and conveying the flash-evaporated liquid ammonia to the first ammonia cooler 2 through an outlet pipeline of the flash tank.
The temperature of the liquid ammonia-liquid ammonia flash tank 10 of the first ammonia separator 4 is 8 ℃, the pressure is 13.29MPa, the temperature of the liquid ammonia-liquid ammonia flash tank 10 of the second ammonia separator 5 is-6 ℃, the pressure is 13.25MPa, and regulating valves are arranged on liquid ammonia pipelines at the outlets of the first ammonia separator 4 and the second ammonia separator 5 and used for controlling the liquid level of the liquid ammonia flash tank 10. The purpose of the flash evaporation of the liquid ammonia in the liquid ammonia flash tank 10 is to remove the hydrogen and nitrogen dissolved in the liquid ammonia and send the flashed hydrogen and nitrogen to an ammonia recovery system. The liquid ammonia flash tank 10 adopts low-pressure flash evaporation, the flash evaporation pressure is 1.8MPa, and the liquid ammonia temperature after flash evaporation is 9.2 ℃.
The ammonia refrigeration system provided by the invention is characterized in that a first regulating valve 101 is arranged on the flash evaporation outlet pipeline, and the first regulating valve 101 is used for controlling the output of liquid ammonia after flash evaporation.
The invention provides an ammonia refrigeration system, wherein a liquid level indicator is arranged in a liquid ammonia flash tank 10.
The ammonia refrigeration system provided by the invention is characterized in that a first anti-surge line is arranged between the ammonia condenser 7 and the first ammonia cooler 2, and a first anti-surge valve 71 is arranged on the first anti-surge line; a second surge-proof line is arranged between the ammonia condenser 7 and the second ammonia cooler 3, and a second surge-proof valve 72 is installed on the second surge-proof line.
The invention provides an ammonia refrigeration system, wherein a first anti-surge valve 71 is arranged at a position close to the shell-side inlet of a first ammonia cooler 2, and a second anti-surge valve 72 is arranged at a position close to the shell-side inlet of a second ammonia cooler 3.
And one part of the ammonia gas from the shell pass of the ammonia condenser 7 is sent to the first ammonia cooler 2 and the second ammonia cooler 3 for preventing surge, and the other part of the ammonia gas is sent to the ammonia compressor 5 for sealing the inner cavity. According to the invention, anti-surge lines are respectively additionally arranged between the ammonia condenser 7 and the first ammonia cooler 2 and the second ammonia cooler 3, so that the ammonia gas in the ammonia condenser 7 enters the ammonia compressor to prevent surge after absorbing heat through the shell passes of the first ammonia cooler 2 and the second ammonia cooler 3, and thus the ammonia gas in the ammonia condenser 7 not only takes away part of heat, but also prevents the ammonia compressor from surging and avoids the ammonia compressor from jumping.
The invention provides an ammonia refrigeration system, wherein a shell pass outlet of a first ammonia cooler 2 is connected with a two-section inlet of an ammonia compressor 6 through a first air outlet pipe, and a first outlet pressure regulating valve 21 is arranged on the first air outlet pipe and used for regulating the pressure of the shell pass of the first ammonia cooler 2; and the shell pass outlet of the second ammonia cooler 3 is connected with one section of inlet of the ammonia compressor 6 through a second air outlet pipe, and a second outlet pressure regulating valve 31 is installed on the second air outlet pipe and used for regulating the pressure of the shell pass of the second ammonia cooler 3. The ammonia gas generated by the first ammonia cooler 2 enters the second section of the ammonia compressor 6 through a first air outlet pipe at the shell pass outlet to be compressed; and the ammonia gas generated by the second ammonia cooler 3 enters a section of the ammonia compressor 6 through a second gas outlet pipe at the shell pass outlet to be compressed.
The invention provides an ammonia refrigeration system, wherein the pressure of the shell side of a first ammonia cooler 2 is greater than the pressure of the shell side of a second ammonia cooler 3. The larger the pressure in the shell pass of the ammonia cooler is, the higher the temperature is, so that the shell pass pressure of the first ammonia cooler 2 is controlled to be about 0.3MPa to ensure the temperature of the shell pass of the first ammonia cooler 2; the shell side pressure of the second ammonia cooler 3 is controlled to be about 0.24MPa so as to ensure that the temperature of the shell side of the second ammonia cooler 3 is about-12 ℃. Meanwhile, liquid level indicators are arranged in the first ammonia cooler 2 and the second ammonia cooler 3, and safety valves are arranged at the tops of the first ammonia cooler and the second ammonia cooler to prevent overpressure of the ammonia coolers.
The ammonia compressor 6 generates heat to cause high temperature when compressing gas ammonia, the degree of the high temperature is related to the compression ratio, and staged compression is adopted to avoid overhigh temperature in the compression process. The gas ammonia from the second ammonia cooler 3 enters a first section of an ammonia compressor 6 for compression, and is compressed to 0.46MPa and then is subjected to second-section compression. The ammonia compressor 6 is provided with an anti-surge line at an outlet of the first section and returns to an inlet of the first section, the pipeline is provided with an anti-surge valve, and the anti-surge line at an outlet of the second section and returns to an inlet of the second section are also provided with anti-surge valves. The ammonia compressor 6 is provided with an anti-surge valve mainly for adjusting the anti-surge flow of the ammonia compressor. Since the ammonia compressor pumping volume decreases as the ammonia compressor load decreases, the ammonia compressor operating curve approaches the surge curve. In order to avoid surge of the ammonia compressor in the process of process fluctuation, the surge-preventing valve is opened, and the pumping circulation quantity of the ammonia compressor is increased to meet the requirement of normal operation of the ammonia compressor.
The ammonia refrigeration system provided by the invention further comprises an information acquisition control system, wherein the information acquisition control system is respectively connected with the liquid level indicator and the valve and is used for receiving and processing signals transmitted by the liquid level indicator and controlling the opening of the valve in the ammonia refrigeration system.
The present invention is provided with a liquid level indicator in a liquid ammonia flash tank 10, a first ammonia cooler 2 and a second ammonia cooler 3, and a liquid level indicator in a liquid ammonia storage tank 1 for preventing the liquid level in the liquid ammonia storage tank from being excessively high and the ammonia compressor from being evacuated due to excessively low liquid level, in addition to a first regulating valve 101 provided on a flash outlet line, a second regulating valve 41 provided on an outlet liquid ammonia line of the liquid ammonia removal flash tank 10 of a first ammonia separator 4, a third regulating valve 51 provided on an outlet liquid ammonia line of the liquid ammonia removal flash tank 10 of a second ammonia separator 5, a fourth regulating valve 22 provided on a communication line of the liquid ammonia removal from the first ammonia cooler 2 to the second ammonia cooler 3, a fifth regulating valve 91 provided on a liquid ammonia line of a liquid ammonia removal ammonia pump 8 of a gas liquid separator 9, a sixth regulating valve 92 provided on an outlet line of the gas removal compressor 6 of the gas separator 9, and an information collection control system including a programmable logic controller P L C and a sensor, and a microprocessor based on a centralized monitor and a dispersion control method for controlling the opening degree of the liquid level indicator, the ammonia removal system, and the control system, thereby ensuring the safety of the operation of the ammonia refrigeration system.
The specific implementation mode of the ammonia refrigeration system provided by the invention is as follows:
the liquid ammonia of the first ammonia cooler 2 and the second ammonia cooler 3 is from the liquid ammonia storage tank 1 during the original driving, and the liquid levels of the two ammonia coolers are established by the liquid ammonia in the liquid ammonia storage tank 1. After the whole system operation is stable, the liquid ammonia of two ammonia coolers all comes from liquid ammonia flash tank 10, if the liquid level of the ammonia cooler can't be guaranteed to the liquid ammonia of liquid ammonia flash tank simultaneously, then utilize the liquid ammonia of liquid ammonia storage tank to supply the liquid level of ammonia cooler. Meanwhile, in order to ensure the separation of the synthesis gas, the liquid levels of the two ammonia coolers are kept between 40 and 50 percent, and the pressure is controlled between 0.2 and 0.4 MPa. The liquid ammonia separated by the first ammonia separator 4 and the second ammonia separator 5 enters a liquid ammonia flash tank 10 for flash evaporation, and the flash evaporated hydrogen and nitrogen are sent to an ammonia recovery system; liquid ammonia from the liquid ammonia flash tank 10 and anti-surge ammonia from the ammonia condenser 7 are merged and then enter a shell pass of the first ammonia cooler 2, and a second section of a gas ammonia removal compressor 6 of the first ammonia cooler 2; the liquid ammonia of the first ammonia cooler 2 is merged with the anti-surge gas ammonia from the ammonia condenser 7 and then enters the shell pass of the second ammonia cooler 3, and the gas ammonia of the second ammonia cooler 3 enters a section of the ammonia removal compressor 6; the gas ammonia from the second ammonia cooler 3 enters a first section of an ammonia compressor 6 for compression, and is compressed to 0.46MPa and then is compressed in a second section, the gas ammonia compressed by the ammonia compressor 6 enters a shell pass of an ammonia condenser 7 for condensation, and a tube pass is cooling medium water; part of the ammonia gas from the shell pass of the ammonia condenser 7 is sent to the first ammonia cooler 2 and the second ammonia cooler 3 for preventing surge, the other part of the ammonia removing compressor 5 is used as inner cavity sealing gas, and condensed liquid ammonia flows to the liquid ammonia storage tank 1 automatically; and the liquid phase of the second ammonia cooler 3 is subjected to gas-liquid separation by a gas-liquid separator 9, and the separated liquid ammonia is conveyed to the liquid ammonia storage tank 1 by a cold ammonia pump 8. In the actual production, the load of the ammonia refrigeration system fluctuates back and forth, and the load is always lower, so that the ammonia amount of the liquid ammonia flash tank (cold ammonia) is less, and the liquid level of the ammonia cooler cannot be ensured, and the liquid level of the ammonia cooler is supplemented by the ammonia in the liquid ammonia storage tank (hot ammonia), so that the liquid ammonia of the second ammonia cooler 3 has a certain amount of gas ammonia, therefore, a gas-liquid separator 9 is arranged in front of the cold ammonia pump 8, so that the liquid ammonia and the gas ammonia of the second ammonia cooler 3 are separated cleanly, and the normal operation of the cold ammonia pump is ensured.
Compared with the prior art, the ammonia refrigeration system provided by the invention has the following advantages: a gas-liquid separator is additionally arranged between the second ammonia separator and the cold ammonia pump, and the gas-phase components in the liquid ammonia are reduced by further separating the liquid ammonia in the second ammonia cooler, so that the normal operation of the cold ammonia pump is ensured; anti-surge lines are respectively additionally arranged between the ammonia condenser and the first ammonia cooler and between the ammonia condenser and the second ammonia cooler, so that gas ammonia in the ammonia condenser enters the ammonia compressor after passing through the first ammonia cooler and the second ammonia cooler, the ammonia compressor is prevented from surging, and the ammonia compressor is prevented from jumping; and the valve opening of the ammonia refrigeration system is remotely controlled by an information acquisition control system, so that the safe and stable operation of the ammonia refrigeration system is ensured.
It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.
Claims (9)
1. An ammonia chilling system comprising: a liquid ammonia storage tank, a first ammonia cooler, a second ammonia cooler, a first ammonia separator, a second ammonia separator, an ammonia compressor, an ammonia condenser and an ammonia cooling pump,
the shell side of the first ammonia cooler is used for receiving liquid ammonia in the liquid ammonia storage tank, the tube side of the first ammonia cooler is used for receiving synthesis gas from an ammonia synthesis tower, gas ammonia generated by the first ammonia cooler enters the ammonia compressor, and the synthesis gas cooled by the first ammonia cooler enters the first ammonia separator;
the first ammonia separator is used for carrying out gas-liquid separation on the cooled synthesis gas to obtain primary gas and liquid ammonia;
the shell side of the second ammonia cooler is used for receiving liquid ammonia of the first ammonia cooler, the tube side of the second ammonia cooler is used for receiving primary gas of the first ammonia separator, gas ammonia generated by the second ammonia cooler enters the ammonia compressor, and the primary gas cooled by the second ammonia cooler enters the second ammonia separator;
the second ammonia separator is used for carrying out gas-liquid separation on the cooled primary gas to obtain secondary gas and liquid ammonia;
the ammonia condenser is used for condensing the gas ammonia compressed by the ammonia compressor to obtain condensed liquid ammonia, and enabling the condensed liquid ammonia to automatically flow to the liquid ammonia storage tank;
the cold ammonia pump is used for conveying the liquid ammonia of the second ammonia cooler to the liquid ammonia storage tank;
the ammonia refrigerating system further comprises a gas-liquid separator, the gas-liquid separator is installed between the second ammonia cooler and the ammonia cooling pump and used for separating liquid ammonia of the second ammonia cooler from liquid ammonia, and the liquid ammonia separated by the gas-liquid separator is conveyed to the liquid ammonia storage tank by the ammonia cooling pump.
2. The ammonia freezing system according to claim 1, further comprising a liquid ammonia flash drum for low-pressure flash evaporating the liquid ammonia separated in the first and second ammonia separators and delivering the flashed liquid ammonia to the first ammonia cooler through a flash drum outlet line.
3. The ammonia chilling system of claim 2, wherein a first control valve is disposed on the flash outlet line for controlling the output of liquid ammonia after flashing.
4. The ammonia chilling system of claim 3, wherein the liquid ammonia flash tank incorporates a liquid level indicator.
5. The ammonia refrigeration system according to claim 1, wherein a first surge-preventing line is provided between the ammonia condenser and the first ammonia cooler, and a first surge-preventing valve is installed on the first surge-preventing line; and a second anti-surge line is arranged between the ammonia condenser and the second ammonia cooler, and a second anti-surge valve is installed on the second anti-surge line.
6. The ammonia refrigeration system of claim 5, wherein the first anti-surge valve is mounted proximate to a first ammonia cooler shell-side inlet and the second anti-surge valve is mounted proximate to a second ammonia cooler shell-side inlet.
7. The ammonia refrigeration system according to claim 1, wherein a shell side outlet of the first ammonia cooler is connected with a second-stage inlet of the ammonia compressor through a first air outlet pipe, and a first outlet pressure regulating valve is mounted on the first air outlet pipe and used for regulating the pressure of the shell side of the first ammonia cooler; and the shell pass outlet of the second ammonia cooler is connected with one section of inlet of the ammonia compressor through a second air outlet pipe, and a second outlet pressure regulating valve is arranged on the second air outlet pipe and used for regulating the pressure of the shell pass of the second ammonia cooler.
8. The ammonia refrigeration system of claim 7, wherein the pressure of the first ammonia cooler shell side is greater than the pressure of the second ammonia cooler shell side.
9. The ammonia refrigeration system according to any one of claims 1-7, further comprising an information collection control system, wherein the information collection control system is respectively connected with the liquid level indicator and the valve, and is used for receiving and processing signals transmitted by the liquid level indicator and controlling the opening of the valve in the ammonia refrigeration system.
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| CN201811068049.5A CN109269224B (en) | 2018-09-13 | 2018-09-13 | Ammonia refrigeration system |
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| CN110005944B (en) * | 2019-04-23 | 2023-11-24 | 内蒙古博大实地化学有限公司 | Energy-saving and consumption-reducing type frozen ammonia conveying system |
| CN112097427B (en) * | 2020-10-21 | 2024-03-08 | 重庆通用工业(集团)有限责任公司 | Liquid removing system and liquid removing method of ice machine |
| CN114857803B (en) * | 2021-02-04 | 2024-04-30 | 中国石油天然气股份有限公司 | Ammonia refrigeration system |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1288947A (en) * | 1968-12-18 | 1972-09-13 | ||
| CN85102389A (en) * | 1985-04-01 | 1986-10-29 | 楼寿林 | Multistage-process for ammonia synthesis |
| CN202470617U (en) * | 2012-03-26 | 2012-10-03 | 新疆宜化化工有限公司 | Gas ammonia compressing and condensing system |
| CN103727710A (en) * | 2013-12-26 | 2014-04-16 | 河南开祥精细化工有限公司 | Liquid ammonia transfer system, liquid ammonia transfer method and ammonia refrigeration system of centrifugal ammonia compressor |
| CN105443402A (en) * | 2015-11-27 | 2016-03-30 | 安徽六国化工股份有限公司 | Centrifugal ammonia compressor unit with dual-cylinder compression three-section air inlet manner |
| CN105883852A (en) * | 2016-04-29 | 2016-08-24 | 湖南安淳高新技术有限公司 | Ammonia synthesis reaction system and method |
| CN106403358A (en) * | 2016-08-30 | 2017-02-15 | 内蒙古博大实地化学有限公司 | Ammonia synthesis device refrigeration system |
| CN206553203U (en) * | 2017-03-16 | 2017-10-13 | 中化重庆涪陵化工有限公司 | Energy-conservation synthesis ammonia space division and instrument supply gas system |
| CN206989470U (en) * | 2017-08-01 | 2018-02-09 | 洪志鹏 | A kind of ammonia compressor energy saver |
| CN207299715U (en) * | 2017-10-09 | 2018-05-01 | 中化重庆涪陵化工有限公司 | Synthesize ammonia space division system |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014127913A2 (en) * | 2013-02-21 | 2014-08-28 | Faramarz Bairamijamal | High pressure process for co2 capture, utilization for heat recovery, power cycle, super-efficient hydrogen based fossil power generation and conversion of liquid co2 with water to syngas and oxygen |
-
2018
- 2018-09-13 CN CN201811068049.5A patent/CN109269224B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1288947A (en) * | 1968-12-18 | 1972-09-13 | ||
| CN85102389A (en) * | 1985-04-01 | 1986-10-29 | 楼寿林 | Multistage-process for ammonia synthesis |
| CN202470617U (en) * | 2012-03-26 | 2012-10-03 | 新疆宜化化工有限公司 | Gas ammonia compressing and condensing system |
| CN103727710A (en) * | 2013-12-26 | 2014-04-16 | 河南开祥精细化工有限公司 | Liquid ammonia transfer system, liquid ammonia transfer method and ammonia refrigeration system of centrifugal ammonia compressor |
| CN105443402A (en) * | 2015-11-27 | 2016-03-30 | 安徽六国化工股份有限公司 | Centrifugal ammonia compressor unit with dual-cylinder compression three-section air inlet manner |
| CN105883852A (en) * | 2016-04-29 | 2016-08-24 | 湖南安淳高新技术有限公司 | Ammonia synthesis reaction system and method |
| CN106403358A (en) * | 2016-08-30 | 2017-02-15 | 内蒙古博大实地化学有限公司 | Ammonia synthesis device refrigeration system |
| CN206553203U (en) * | 2017-03-16 | 2017-10-13 | 中化重庆涪陵化工有限公司 | Energy-conservation synthesis ammonia space division and instrument supply gas system |
| CN206989470U (en) * | 2017-08-01 | 2018-02-09 | 洪志鹏 | A kind of ammonia compressor energy saver |
| CN207299715U (en) * | 2017-10-09 | 2018-05-01 | 中化重庆涪陵化工有限公司 | Synthesize ammonia space division system |
Non-Patent Citations (1)
| Title |
|---|
| "合成氨装置氨冷冻***优化";姜义君，胡耀武;《大氮肥》;20080829;第31卷(第4期);第220-222页 * |
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