Partitioned on-demand water supply method for circulating water in synthetic ammonia production

Abstract

The invention relates to the field of synthetic ammonia and other industrial production in the coal chemical industry, and particularly provides a synthetic ammonia production circulating water partition on-demand water supply method which comprises a cold water pool, the cold water pool is connected with a circulating water low-area water pump through a cold water pipeline, and the cold water pipeline is further provided with a circulating water low-area pump inlet valve; one path of circulating water low-area water pump outlet is connected with a low-position heat exchanger inlet pipeline through a low-area pump outlet pipeline and a flow regulating valve, and circulating water return water returns to the water cooling tower from the low-position heat exchanger through a water cooling tower return water main pipe; after circulating water at an outlet of the circulating water low-area water pump continues to be pressurized through the pipeline pump, the high-position heat exchanger is connected with a water return main pipe through a circulating water return pipeline, and the circulating water after heat exchange is connected with a water cooling tower spray head. And circulating cold water falls into the cold water pool through the corrugated packing by virtue of self gravity to finish the circulating process. Compared with the prior art, the purpose of saving electricity and energy for circulating water of a synthetic ammonia and urea system can be achieved.

Description

Technical Field

[0001] The invention relates to the fields of coal chemical synthesis ammonia and other industrial production, and specifically provides a method for supplying circulating water by partition on demand in the production of synthetic ammonia. Background Art

[0002] In the modern coal chemical synthetic ammonia and urea process production process, the system production needs to go through preheating, reaction, waste heat recovery, cooling and cooling, and product separation processes. Among them, the cooling and cooling process affects the separation efficiency of the products after the reaction and the consumption of the synthetic ammonia system. The current synthetic ammonia and urea process flow and equipment pipeline layout requirements have large position differences between the installation positions of the circulating water heat exchanger equipment. The highest and lowest heat exchangers of the synthetic ammonia circulating water heat exchanger have a position difference of 20m, and the maximum position difference between the circulating water heat exchanger equipment of the urea unit is about 35m. In order to ensure the water supply demand of the highest circulating water heat exchanger, it is necessary to design the circulating water supply pressure according to the most unfavorable point heat exchanger, so that the circulating water pressure is higher for the low-position heat exchanger, resulting in the consumption of most of the power of the circulating water pump and increasing production costs.

[0003] (1) The inlet and outlet of the circulating water pump are both manually adjusted, which makes it impossible to achieve real-time and quantitative adjustment of the valve opening. Since the fixed mode is operated throughout the year, the overall power consumption is bound to increase.

[0004] (2) There is a lack of effective data monitoring on the various water-using branches of the circulating water system, and the flow is not used intensively, resulting in insufficient flow utilization efficiency.

[0005] (3) The open operation of circulating water results in large evaporation losses and water quality fluctuations, and the amount of make-up water is not adjusted in a timely manner, resulting in calcium hardness and concentration multiples exceeding the index and rapid deterioration of water quality, which has a huge impact on the economic operation of the production system. Summary of the invention

[0006] The present invention aims at the above-mentioned deficiencies of the prior art and provides a highly practical method for supplying circulating water by partition on demand in synthetic ammonia production.

[0007] The technical solution adopted by the present invention to solve its technical problem is:

[0008] A method for supplying circulating water in different zones on demand for synthetic ammonia production comprises a cooling water tank, wherein the cooling water tank is connected to a circulating water low zone water pump via a cooling water pipeline, and the cooling water pipeline is also provided with a circulating water low zone pump inlet valve;

[0009] The outlet of the low-level pump of the circulating water is connected to the inlet pipe of the low-level heat exchanger through the outlet pipe of the low-level pump and the flow regulating valve. As the refrigerant medium, the temperature of the process side of the low-level heat exchanger is reduced through the partition heat exchange form. After the temperature itself is increased, the circulating water return water is connected to the cooling tower return water main pipe from the low-level heat exchanger through the outlet pipe and returns to the cooling tower;

[0010] The other path flows through the low-zone pump outlet pipeline and the pipeline pump inlet pipeline to connect the pipeline pump. The pipeline pump inlet pipeline is provided with a pipeline pump inlet valve. After the circulating water at the outlet of the low-zone water pump is further pressurized by the pipeline pump, it is connected to the high-position heat exchanger through the pipeline pump outlet valve, the high-position heat exchanger circulating water inlet flow regulating valve and the high-position heat exchanger circulating water inlet pipeline. The high-position heat exchanger is connected to the return water main pipe through the circulating water return pipe. The circulating water after heat exchange is connected to the cooling tower nozzle through the return water main pipe. The cooling tower nozzle is provided with corrugated filler at the bottom and a cooling tower fan at the top;

[0011] The dry cold air drawn from the surroundings to the center by the cooling tower fan is evenly contacted with the returning circulating water for heat exchange. After the circulating water return temperature is reduced, the circulating water falls into the cooling water pool through the corrugated packing by its own gravity to complete the circulation process.

[0012] Furthermore, a low zone pump outlet pressure remote display is provided on the low zone pump outlet pipeline. According to the value of the low zone pump outlet pressure remote display, the circulating water low zone pump inlet water volume is controlled through the circulating water low zone pump inlet valve 3, and the circulating water pressure at the circulating water low zone pump outlet is adjusted to meet the pressure requirement at the circulating water inlet of the low-level heat exchanger.

[0013] Furthermore, a circulating water upper water temperature remote display is also provided on one side of the remote display of the outlet pressure of the low zone pump, and a circulating water return water temperature remote display is provided on the circulating water return pipe, the circulating water upper water temperature remote display is the circulating water temperature at the inlet of the low-level heat exchanger, and the circulating water return water temperature remote display is the circulating water temperature at the outlet of the low-level heat exchanger;

[0014] Monitor the difference between the circulating water temperature at the inlet and outlet of the low-level heat exchanger, set the circulating water volume through the flow meter to control the opening of the flow regulating valve. When the difference between the circulating water inlet and outlet temperatures is too large, increase the set value of the flow meter, increase the opening of the flow regulating valve, increase the circulating water volume at the inlet of the low-level heat exchanger, and reduce the difference between the circulating water inlet and outlet temperatures to within the index, thereby achieving on-demand water supply to the low-level heat exchanger.

[0015] Furthermore, a high-zone heat exchanger circulating water inlet pressure display is provided on the high-zone heat exchanger circulating water inlet pressure display, and the pipeline pump circulating water outlet pressure is monitored by the high-zone heat exchanger circulating water inlet pressure display. When the high-zone heat exchanger circulating water inlet pressure display is lower than the circulating water pressure index required by the high-zone heat exchanger design, the pipeline pump inlet valve is adjusted to increase the opening, increase the inlet circulating water volume of the pipeline pump, meet the high-zone heat exchanger circulating water inlet pressure index requirement, and realize the zoned water supply of circulating water pressures of heat exchangers with different elevations in the synthetic ammonia and urea production system.

[0016] Furthermore, a high-level heat exchanger circulating water inlet flowmeter is provided on the high-level heat exchanger circulating water inlet pipe, and a high-level heat exchanger circulating water return temperature remote display is provided on the high-level heat exchanger outlet pipe, and the high-level heat exchanger circulating water return temperature remote display shows the circulating water temperature value at the high-level heat exchanger outlet;

[0017] When monitoring the numerical difference between the circulating water temperature at the inlet and outlet of the high-level heat exchanger, the circulating water volume is set by the circulating water inlet flow meter of the high-level heat exchanger to control the opening of the circulating water inlet flow regulating valve of the high-level heat exchanger. When the numerical difference between the circulating water inlet temperature and the circulating water outlet temperature is too large, it is necessary to increase the set value of the circulating water inlet flow meter of the high-level heat exchanger, increase the opening of the circulating water inlet flow regulating valve of the high-level heat exchanger, increase the circulating water volume at the inlet of the low-level heat exchanger, and reduce the numerical difference between the circulating water inlet temperature and the circulating water outlet temperature to within the index, so as to realize on-demand water supply of the high-level heat exchanger.

[0018] Furthermore, the cooling water pool is provided with a cooling water pool liquid level remote display, the cooling water pipeline is provided with a circulating water replenishment valve, and the cooling water pool liquid level remote display cooperates with the circulating water replenishment valve;

[0019] The liquid level indicator of the cooling water tank is remotely displayed, and is adjusted through the circulating water replenishment valve to adjust the circulating water replenishment amount, stabilize the liquid level indicator of the cooling water tank remotely displayed, and ensure the continuous, cyclical and stable operation of the circulating water partition water supply on demand.

[0020] Furthermore, an online water quality analysis display is provided on the cooling water pipeline near the inlet valve of the circulating water low zone pump, a drainage pipeline is connected to the return water main pipe, a drainage valve is provided on the drainage pipeline, and the online water quality analysis display cooperates with the drainage valve;

[0021] The online water quality analysis displays and analyzes the circulating water's calcium ion hardness, pH, and concentration multiples. By adjusting the drainage valve on the circulating water drainage pipeline, the circulating water drainage volume and drainage replacement volume are adjusted.

[0022] Furthermore, when the online water quality analysis shows that the calcium ion hardness, pH and concentration ratio of the monitored circulating water are high and exceed the standard, the drainage valve is opened to increase the drainage volume of the circulating water device;

[0023] After the drainage volume increases, the circulating water balance is broken, the circulating water cooling pool liquid level remote transmission shows that the liquid level is reduced, the interlocking circulating water replenishment valve is opened and adjusted, the circulating water replenishment water volume is increased, and the circulating water calcium ion hardness, PH, and concentration multiple indicators are reduced. After that, the drainage valve on the circulating water drainage pipeline is adjusted to adjust the circulating water drainage volume and the drainage replacement volume;

[0024] When the online water quality analysis shows that the monitored circulating water calcium ion hardness, pH and concentration multiple values ​​are within the safe and stable operation indicators, the drain valve is gradually adjusted to reduce the circulating water discharge. After the discharge volume is adjusted, the circulating water balance is broken again. The remote transmission of the circulating water cooling tank level shows that the liquid level is gradually rising. The interlocked circulating water make-up valve is closed and adjusted to reduce the circulating water make-up water volume, stabilize the circulating water calcium ion hardness, pH and concentration multiple indicators, and ensure the continuous, cyclic, safe and long-term stable operation of the circulating water zone on-demand water supply device.

[0025] Compared with the prior art, the method for supplying circulating water by partition in synthetic ammonia production on demand has the following outstanding beneficial effects:

[0026] The present invention realizes the purpose of power saving and energy conservation of circulating water in synthetic ammonia and urea systems by operating the circulating water low zone water pump and pipeline pump in stages and multiple stages under pressure.

[0027] By monitoring the circulating water flow at the heat exchanger inlet, the inlet and outlet temperature difference and automatic adjustment, the cooling medium of the heat exchanger can be stabilized, the stability of the heat exchange efficiency of the cooler can be ensured, and the maximum circulating water operation mode can be changed to achieve low circulating water circulation volume operation. While saving electricity, it can reduce the evaporation loss of circulating water, reduce the water replenishment volume and water efficiency operation indicators.

[0028] Through online water quality analysis and water replenishment and drainage valve control, a balanced coupling between water replenishment and drainage replacement is achieved, the calcium hardness of circulating water and the safe operation index of concentration multiple are reduced, and long-term stable operation of heat exchange equipment and production systems is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Attached Figure 1 The present invention is a schematic flow diagram of a method for supplying circulating water in different zones on demand for synthetic ammonia production;

[0031] The symbols in the accompanying drawings represent:

[0032] 1. Cooling water pool, 2. Cooling water pipeline, 3. Circulating water low zone pump inlet valve, 4. Circulating water low zone pump, 5. Low zone pump outlet pipeline, 6. Flow meter, 7. Flow regulating valve, 8. Return water main, 9. Low position heat exchanger, 10. Pipeline pump inlet valve, 11. Pipeline pump, 12. Pipeline pump outlet valve, 13. High position heat exchanger circulating water inlet flow meter, 14. High position heat exchanger circulating water inlet flow regulating valve, 15. High zone heat exchanger circulating water inlet pipeline, 16. High zone heat exchanger circulating water inlet pressure display , 17. High-level heat exchanger, 18. Circulating water return pipe, 19. Cooling tower fan, 20. Corrugated packing, 21. Nozzle, 22. Pipeline pump inlet pipe, 23. Circulating water supply temperature remote display, 24. Circulating water return temperature remote display from low-level heat exchanger, 25. Circulating water return temperature remote display from high-level heat exchanger, 26. Low-zone pump outlet pressure remote display, 27. Cooling water tank liquid level remote display, 28. Circulating water replenishment valve, 29. Online water quality analysis display, 30. Drain valve. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] A best embodiment is given below:

[0035] like Figure 1 As shown, a method for supplying circulating water by zones according to demand in synthetic ammonia production in this embodiment includes a cooling water tank 1, which is connected to a circulating water low zone water pump 4 through a cooling water pipe 2, and a circulating water low zone pump inlet valve 3 is also provided on the cooling water pipe 2. Circulating water in the production process of synthetic ammonia and urea is collected through the cooling water tank 1, connected to the inlet of the circulating water low zone water pump 4 through the cooling water pipe 2, and a valve 3 is added to the cooling water pipe 2 for control. The cooling water is pressurized by the circulating water low zone water pump 4 to increase the head to the required pressure of 0.30Mpa for the low-level heat exchanger 9.

[0036] The outlet of the low-zone water pump 4 of one path of circulating water is connected to the inlet pipe of the low-level heat exchanger 9 through the low-zone pump outlet pipe 5 and the flow regulating valve 7. As a refrigerant medium, it reduces the temperature of the process side of the low-level heat exchanger 9 through the partition heat exchange form. After its own temperature is increased, the circulating water return is connected from the low-level heat exchanger 9 to the cooling tower through the cooling tower return water main pipe 8 and returned to the cooling tower.

[0037] The other path flows through the low-zone pump outlet pipe 5 and the pipeline pump inlet pipe 22 to connect to the pipeline pump 11. The pipeline pump inlet pipe 22 is provided with a pipeline pump inlet valve 10. The circulating water at the outlet of the low-zone water pump continues to increase its pressure from 0.3MPa to 0.45MPa through the pipeline pump 11, and is connected to the high-position heat exchanger 17 through the pipeline pump outlet valve 12, the high-position heat exchanger circulating water inlet flow regulating valve 14 and the high-zone heat exchanger circulating water inlet pipe 15. After overcoming the high energy loss, the circulating water pressure requirement of the high-position heat exchanger 17 of 0.3-0.32MPa is met. The high-position heat exchanger 17 is connected to the return water main 8 through the circulating water return pipe 18. The circulating water after heat exchange is connected to the cooling tower nozzle 21 through the return water main 8. The cooling tower nozzle 21 is provided with a corrugated filler 20 at the bottom and a cooling tower fan 19 at the top.

[0038] The cooling tower fan 19 draws dry cold air from the periphery toward the center of the circle and exchanges heat with the circulating water evenly. After the circulating water return temperature is reduced, the circulating water falls into the cooling water pool 1 through the corrugated packing 20 by its own gravity to complete the circulation process.

[0039] Among them, a low zone pump outlet pressure remote display 26 is provided on the low zone pump outlet pipe 5. According to the value of the low zone pump outlet pressure remote display 26, the inlet water volume of the circulating water low zone water pump 4 is controlled through the circulating water low zone pump inlet valve 3, and the circulating water pressure at the outlet of the circulating water low zone water pump 4 is adjusted to meet the pressure requirement at the circulating water inlet of the low-level heat exchanger 9.

[0040] A circulating water upper water temperature remote display 23 is also provided on one side of the low zone pump outlet pressure remote display 26, and a circulating water return water temperature remote display 24 is provided on the circulating water return pipe 18. The circulating water upper water temperature remote display 23 indicates the circulating water temperature at the inlet of the low position heat exchanger 9, and the circulating water return water temperature remote display 24 indicates the circulating water temperature at the outlet of the low position heat exchanger 9;

[0041] Monitor the numerical difference between the circulating water temperature at the inlet and outlet of the low-level heat exchanger 9, set the circulating water volume through the flow meter 6 to control the opening of the flow regulating valve 7. When the numerical difference between the circulating water inlet and outlet temperatures is too large, it is necessary to increase the set value of the flow meter 6, increase the opening of the flow regulating valve 7, increase the circulating water volume at the inlet of the low-level heat exchanger 9, and reduce the numerical difference between the circulating water inlet and outlet temperatures within the 6-8°C index, so as to achieve the purpose of supplying water to the low-level heat exchanger 9 on demand.

[0042] A high-zone heat exchanger circulating water inlet pressure display 16 is provided on the high-zone heat exchanger circulating water inlet pipe 15. The circulating water outlet pressure of the pipeline pump is monitored through the high-zone heat exchanger circulating water inlet pressure display 16. When the high-zone heat exchanger circulating water inlet pressure display is less than the circulating water pressure index of the high-zone heat exchanger design requirement of 0.30MPa, the pipeline pump inlet valve 10 is adjusted to increase the opening, increase the inlet circulating water volume of the pipeline pump 11, meet the high-zone heat exchanger circulating water inlet pressure index requirement, and realize the zoned water supply of circulating water pressure of heat exchangers with different elevations in the synthetic ammonia and urea production system.

[0043] A high-level heat exchanger circulating water inlet flowmeter 13 is provided on the high-level heat exchanger circulating water inlet pipe 15, and a high-level heat exchanger circulating water return water temperature remote display 25 is provided on the high-level heat exchanger outlet pipe 17. The high-level heat exchanger circulating water return water temperature remote display 25 displays the circulating water temperature value at the outlet of the high-level heat exchanger 17;

[0044] When monitoring the numerical difference between the circulating water temperature at the inlet and outlet of the high-level heat exchanger, the circulating water volume is set by the high-level heat exchanger circulating water inlet flowmeter 13 to control the opening of the high-level heat exchanger circulating water inlet flow regulating valve 14. When the numerical difference between the circulating water inlet temperature and the circulating water outlet temperature is too large, it is necessary to increase the set value of the high-level heat exchanger circulating water inlet flowmeter 13, increase the opening of the high-level heat exchanger circulating water inlet flow regulating valve 14, increase the circulating water volume at the inlet of the low-level heat exchanger 9, and reduce the numerical difference between the circulating water inlet temperature and the circulating water outlet temperature to within the index, so as to realize the high-level heat exchanger 17 to supply water on demand.

[0045] A cooling water tank level remote display 27 is provided at the cooling water tank 1, and a circulating water replenishment valve 28 is provided on the cooling water pipe 2. The cooling water tank level remote display 27 cooperates with the circulating water replenishment valve 28;

[0046] The liquid level indicator 27 of the cooling water tank is remotely displayed, and is adjusted through the circulating water replenishment valve 28 to adjust the circulating water replenishment amount and stabilize the liquid level indicator 27 of the cooling water tank remotely displayed, thereby ensuring the continuous, cyclical and stable operation of the circulating water partition according to demand water supply.

[0047] An online water quality analysis display 29 is also provided on the cooling water pipe 2 near the circulating water low zone pump inlet valve 3, a drainage pipe is connected to the return water main pipe 8, a drainage valve 30 is provided on the drainage pipe, and the online water quality analysis display 29 cooperates with the drainage valve 30;

[0048] The online water quality analysis display 29 analyzes and monitors the circulating water calcium ion hardness, pH, and concentration multiple indicators, and adjusts the circulating water drainage volume and the drainage replacement volume through the drainage valve 30 on the circulating water drainage pipeline.

[0049] When the online water quality analysis shows 29 that the calcium ion hardness, pH, and concentration multiple of the monitored circulating water are high and exceed the standard, the drainage valve 30 is opened to increase the drainage volume of the circulating water device;

[0050] After the drainage volume increases, the circulating water balance is broken, the liquid level of the circulating water cooling pool remote display 27 decreases, the interlocking circulating water replenishment valve 28 is opened and adjusted, the circulating water replenishment water volume is increased, and the circulating water calcium ion hardness, PH, and concentration multiple indicators are reduced. After the drainage valve 30 on the circulating water drainage pipeline is adjusted, the circulating water drainage volume is adjusted, and the drainage replacement volume is adjusted;

[0051] When the online water quality analysis shows 29 that the values ​​of calcium ion hardness, pH and concentration multiple of the monitored circulating water are within the safe and stable operation indicators, the drainage valve 30 is gradually adjusted to reduce the drainage volume of the circulating water. After the drainage volume is adjusted, the circulating water balance is broken again. The remote transmission of the liquid level in the circulating water cooling pool shows 27 that the liquid level gradually rises. The interlocked circulating water replenishment valve 28 is closed and adjusted to reduce the circulating water replenishment water volume, stabilize the circulating water calcium ion hardness, pH and concentration multiple indicators, and ensure the continuous, cyclic, safe and long-term stable operation of the circulating water zone on-demand water supply device.

[0052] Taking a 500,000-ton synthetic ammonia and urea unit as an example, the circulating cooling water volume is 18,000 m3 / h, and the designed circulating water pressure at the heat exchanger inlet is 0.35 MPa.

[0053] 1. Before the implementation of circulating water zoning and on-demand water supply, the pump head is designed to be 42m; the power calculation formula of the circulating water pump is: P = p*g*Q*H / 1000, where P is the pump power (kW) and p is the density of water (kg / m 3 ), g is the acceleration due to gravity (9.81m / s 2 ), Q is the flow rate (m 3 / s), H is the head (m):

[0054] Then: Q1 = 18000 / 3600 = 5m 3 / s

[0055] Before the circulating water is divided into zones and supplied on demand, P1=1000*9.81*5*42 / 1000=2060kw.

[0056] 2. After implementing the circulating water zoning and water supply on demand, the water pump head in the low area is 28m and the flow rate is 18000m3 / h; the water pump head in the high area is 12m and the flow rate is 3000m3 / h;

[0057] Then: Q low = 18000 / 3600 = 5m 3 / s, Q high = 3000 / 3600 = 0.83m 3 / s;

[0058] P low = 1000 * 9.81 * 5 * 28 / 1000 = 1373.4kw;

[0059] P high = 1000 * 9.81 * 0.83 * 12 / 1000 = 98kw;

[0060] After implementing circulating water partition and water supply on demand, the total power P2 = P low + P high = 1373.4 + 98 = 1471.5kw;

[0061] After circulating water is divided into zones and supplied on demand, the water pump can save electricity consumption: P1-P2=2060-1471.5=588.5kw.

[0062] Taking 500,000 tons of synthetic ammonia as an example, it can be calculated that the power consumption of circulating water can be reduced by 550kw / h, standard coal can be saved by 1,340t / year, the circulating water volume can be reduced by 15%, and the replenishment volume of evaporation loss can be reduced by 75m3 / h. Set up online water quality analysis instruments and control systems for circulating water, and realize the balanced coupling of circulating water replenishment and drainage by monitoring the changes in circulating water calcium hard ions and concentration multiples, stabilize the circulating water operation indicators, and ensure the water safety of the cooling system.

[0063] The above-mentioned specific implementations are only specific cases of the present invention. The patent protection scope of the present invention includes but is not limited to the above-mentioned specific implementations. Any technical solutions that conform to the above-mentioned specific implementations of the present invention and any appropriate changes or substitutions made by ordinary technicians in the relevant technical field shall fall within the patent protection scope of the present invention.

[0064] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for supplying circulating water by zones according to demand in synthetic ammonia production, characterized in that: It includes a cooling water pool, the cooling water pool is connected to the circulating water low zone water pump through a cooling water pipeline, and the cooling water pipeline is also provided with a circulating water low zone pump inlet valve; The outlet of the low-level water pump of one circulating water is connected to the inlet pipe of the low-level heat exchanger through the outlet pipe of the low-level pump and the flow regulating valve. As the refrigerant medium, it reduces the temperature of the process side of the low-level heat exchanger through the partition heat exchange form. After its own temperature is increased, the circulating water return water is connected to the cooling tower through the cooling tower return water main pipe from the low-level heat exchanger; The other path flows through the low-zone pump outlet pipeline and the pipeline pump inlet pipeline to connect the pipeline pump. The pipeline pump inlet pipeline is provided with a pipeline pump inlet valve. After the circulating water at the outlet of the low-zone water pump is further pressurized by the pipeline pump, it is connected to the high-position heat exchanger through the pipeline pump outlet valve, the high-position heat exchanger circulating water inlet flow regulating valve and the high-position heat exchanger circulating water inlet pipeline. The high-position heat exchanger is connected to the return water main pipe through the circulating water return pipe. The circulating water after heat exchange is connected to the cooling tower nozzle through the return water main pipe. The cooling tower nozzle is provided with corrugated filler at the bottom and cooling tower fan at the top; The dry cold air drawn from the surroundings to the center by the cooling tower fan is evenly contacted with the returning circulating water for heat exchange. After the circulating water return temperature is reduced, the circulating water falls into the cooling water pool through the corrugated packing by its own gravity to complete the circulation process.

2. A method for supplying circulating water by zones according to claim 1, characterized in that: The low zone pump outlet pipe is provided with a remote display of the low zone pump outlet pressure. According to the value of the remote display of the low zone pump outlet pressure, the inlet water volume of the circulating water low zone pump is controlled through the circulating water low zone pump inlet valve, and the circulating water pressure at the outlet of the circulating water low zone pump is adjusted to meet the pressure requirement at the circulating water inlet of the low-level heat exchanger.

3. A method for supplying circulating water by zones according to claim 2, characterized in that: The remote display of the outlet pressure of the low zone pump is also provided with a remote display of the circulating water upper water temperature. The circulating water return pipe is provided with a remote display of the circulating water return temperature of the low-level heat exchanger. The circulating water upper water temperature remote display shows the circulating water temperature at the inlet of the low-level heat exchanger, and the circulating water return temperature remote display shows the circulating water temperature at the outlet of the low-level heat exchanger. Monitor the difference between the circulating water temperature at the inlet and outlet of the low-level heat exchanger, set the circulating water volume through the flow meter to control the opening of the flow regulating valve. When the difference between the circulating water inlet and outlet temperatures is too large, increase the set value of the flow meter, increase the opening of the flow regulating valve, increase the circulating water volume at the inlet of the low-level heat exchanger, and reduce the difference between the circulating water inlet and outlet temperatures to within the index, thereby achieving on-demand water supply to the low-level heat exchanger.

4. A method for supplying circulating water by zones according to claim 3, characterized in that: The high-zone heat exchanger circulating water inlet pipe is provided with a high-zone heat exchanger circulating water inlet pressure display, and the pipeline pump circulating water outlet pressure is monitored by the high-zone heat exchanger circulating water inlet pressure display. When the high-zone heat exchanger circulating water inlet pressure display is lower than the circulating water pressure index required by the high-zone heat exchanger design, the pipeline pump inlet valve is adjusted to increase the opening, increase the inlet circulating water volume of the pipeline pump, meet the high-zone heat exchanger circulating water inlet pressure index requirement, and realize the zoned water supply of circulating water pressure of heat exchangers with different elevations in the synthetic ammonia and urea production system.

5. A method for supplying circulating water by zones according to claim 4, characterized in that: A high-level heat exchanger circulating water inlet flowmeter is provided on the high-level heat exchanger circulating water inlet pipe, and a high-level heat exchanger circulating water return temperature remote display is provided on the high-level heat exchanger outlet pipe, and the high-level heat exchanger circulating water return temperature remote display shows the circulating water temperature value at the high-level heat exchanger outlet; When monitoring the numerical difference between the circulating water temperature at the inlet and outlet of the high-level heat exchanger, the circulating water volume is set by the circulating water inlet flow meter of the high-level heat exchanger to control the opening of the circulating water inlet flow regulating valve of the high-level heat exchanger. When the numerical difference between the circulating water inlet temperature and the circulating water outlet temperature is too large, it is necessary to increase the set value of the circulating water inlet flow meter of the high-level heat exchanger, increase the opening of the circulating water inlet flow regulating valve of the high-level heat exchanger, increase the circulating water volume at the inlet of the low-level heat exchanger, and reduce the numerical difference between the circulating water inlet temperature and the circulating water outlet temperature to within the index, so as to realize on-demand water supply of the high-level heat exchanger.

6. A method for supplying circulating water by zones according to claim 5, characterized in that: The cooling water pool is provided with a cooling water pool liquid level remote display, and the cooling water pipeline is provided with a circulating water replenishment valve, and the cooling water pool liquid level remote display cooperates with the circulating water replenishment valve; The liquid level indicator of the cooling water tank is remotely displayed, and is adjusted through the circulating water replenishment valve to adjust the circulating water replenishment amount, stabilize the liquid level indicator of the cooling water tank remotely displayed, and ensure the continuous, cyclical and stable operation of the circulating water partition water supply on demand.

7. A method for supplying circulating water by zones according to claim 6, characterized in that: An online water quality analysis display is also provided on the cooling water pipeline near the inlet valve of the circulating water low zone pump. A drainage pipeline is connected to the return water main pipe, and a drainage valve is provided on the drainage pipeline. The online water quality analysis display cooperates with the drainage valve. The online water quality analysis displays and analyzes the circulating water's calcium ion hardness, pH, and concentration multiples. By adjusting the drainage valve on the circulating water drainage pipeline, the circulating water drainage volume and drainage replacement volume are adjusted.

8. A method for supplying circulating water by zones according to demand in synthetic ammonia production according to claim 7, characterized in that: When the online water quality analysis shows that the calcium ion hardness, pH and concentration ratio of the monitored circulating water are high and exceed the standard, open the drainage valve to increase the drainage volume of the circulating water device; After the drainage volume increases, the circulating water balance is broken, the circulating water cooling pool liquid level remote transmission shows that the liquid level is reduced, the interlocking circulating water replenishment valve is opened and adjusted, the circulating water replenishment water volume is increased, and the circulating water calcium ion hardness, PH, and concentration multiple indicators are reduced. After that, the drainage valve on the circulating water drainage pipeline is adjusted to adjust the circulating water drainage volume and the drainage replacement volume; When the online water quality analysis shows that the monitored circulating water calcium ion hardness, pH and concentration multiple values ​​are within the safe and stable operation indicators, the drain valve is gradually adjusted to reduce the circulating water discharge. After the discharge volume is adjusted, the circulating water balance is broken again. The remote transmission of the circulating water cooling tank level shows that the liquid level is gradually rising. The interlocked circulating water make-up valve is closed and adjusted to reduce the circulating water make-up water volume, stabilize the circulating water calcium ion hardness, pH and concentration multiple indicators, and ensure the continuous, cyclic, safe and long-term stable operation of the circulating water zone on-demand water supply device.

Images