An efficient evaporation system control system

Abstract

The utility model belongs to evaporative system control field, specifically discloses a kind of efficient evaporative system control system, including the top of crystallizer is equipped with remote pressure gauge PT01, the top of crystallizer is connected and is equipped with steam regulating valve PV01 on gas phase pipeline, for calculating the boiling point of liquid under this pressure by antoine formula, the pressure of crystallizer top is adjusted by adjusting the opening of steam regulating valve;Including the shell side of heater is equipped with remote pressure gauge PT03, steam regulating valve PV02 is installed on steam delivery pipeline, for calculating the boiling point of liquid under this pressure by antoine formula, the pressure of heater shell side is adjusted by adjusting the opening of steam regulating valve.The control system of the utility model can realize the automatic regulation of evaporative system, reduce artificial operation, reduce operator's work intensity, improve system operating efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of evaporation system control, and specifically relates to a high-efficiency evaporation system control system. Background Technology

[0002] An evaporation system is an industrial equipment combination that uses heating to vaporize and remove part of the solvent (usually water) in a solution, thereby increasing the solution concentration or recovering the solvent. It is a very common unit operation in chemical, food, pharmaceutical, environmental protection (wastewater treatment), and seawater desalination industries. Its core principle is energy and mass balance; that is, by inputting heat energy (usually steam) to evaporate the solvent, the generated secondary steam is separated from the concentrate. Currently, evaporation devices have relatively crude control over system temperature and pressure, resulting in large fluctuations in system temperature and pressure, unstable system operation, reduced production efficiency, and low thermal energy utilization efficiency, which does not conform to the current industry trend of energy conservation and emission reduction. Utility Model Content

[0003] The purpose of this invention is to provide a highly efficient evaporation system control system that can automatically adjust the evaporation system, reduce manual operation, alleviate the workload of operators, and improve system operating efficiency.

[0004] To achieve the above objectives, this utility model provides a highly efficient evaporation system control system, including a crystallizer. A remote pressure gauge PT01 is installed on the top of the crystallizer, and a waste steam regulating valve PV01 is installed on the gas phase pipeline connected to the top of the crystallizer. The valve is used to calculate the temperature FX01 of the liquid saturated vapor corresponding to the remote pressure gauge PT01 using the Antoni formula, and to adjust the pressure at the top of the crystallizer by adjusting the opening of the waste steam regulating valve PV01.

[0005] Optionally, the lower part of one side of the crystallizer is connected to the bottom of the heater via a pipeline, and the top of the heater is connected to the middle part of the other side of the crystallizer via a pipeline. An axial flow pump is installed on the pipeline connecting the lower part of the crystallizer to the bottom of the heater. A steam delivery pipeline is connected to the upper part of the side of the heater away from the crystallizer.

[0006] Furthermore, the heater is a shell-and-tube heater, with a remote pressure gauge PT03 installed on its shell side. A steam regulating valve PV02 is installed on the steam delivery pipeline to calculate the temperature FX03 of the liquid saturated steam corresponding to the remote pressure gauge PT03 using the Antoni formula. The shell-side pressure of the heater is adjusted by adjusting the opening of the steam regulating valve PV02.

[0007] Optionally, the lower part of the heater on the side away from the crystallizer is connected to the top of the condensate tank via a pipeline, and the condensate tank is equipped with a condensate pump via a pipeline, and the outlet of the condensate pump is connected to a condensate discharge pipeline.

[0008] Furthermore, the condensate discharge pipeline is connected to the steam transmission pipeline via a steam pipeline desuperheating water injection pipeline. A pressure transmitter PT02 and a temperature transmitter TT02 are sequentially installed on the side of the steam transmission pipeline near the heater before the steam regulating valve PV02, with the temperature transmitter TT02 located before the steam pipeline desuperheating water injection pipeline. The desuperheating water injection line of the steam pipeline is equipped with a desuperheating water regulating valve TV01, which is used to calculate the temperature FX02 of the liquid saturated steam corresponding to the pressure transmitter PT02 using the Antoni formula. The temperature of the steam entering the heater is adjusted by adjusting the opening of the desuperheating water regulating valve TV01 to avoid the steam from becoming oversaturated and affecting the heat transfer efficiency.

[0009] Optionally, the crystallizer has a feed inlet on the lower part of the side away from the heater, and a gas phase pipeline is connected to the top of the crystallizer.

[0010] Preferably, the exhaust steam regulating valve PV01, the steam regulating valve PV02, and the desuperheating water regulating valve TV01 are all pneumatic V-type regulating shut-off valves.

[0011] In summary, compared with the prior art, the efficient evaporation system control system of this utility model has the following beneficial effects: 1. This system is suitable for various types of evaporation systems, such as single-effect evaporation, multi-effect evaporation, rising / falling film evaporation, and MVR evaporation. It can achieve precise control of crystallizer pressure and improve the flash evaporation efficiency of liquid in the crystallizer.

[0012] 2. This system can precisely adjust the shell-side pressure of the heater by adjusting the steam consumption, thereby avoiding overheating and overpressure of the equipment and reducing the probability of scale buildup in the heater.

[0013] 3. This system can adjust the amount of desuperheating water according to the temperature and pressure of the steam entering the heater, so as to avoid the oversaturation of the heating steam and improve the thermal efficiency of the steam. Attached Figure Description

[0014] To more clearly illustrate the technical solution of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a system process flow diagram of this utility model.

[0016] In the attached image: a- Crystallizer; b- Heater; c- Condensate tank; d- Condensate pump; e- Axial flow pump; ①-Remote pressure gauge PT01; ②-Temperature of saturated liquid vapor FX01; ③-BPRI01; ④-Heater inlet liquid temperature TT01; ⑤-Remote pressure gauge PT03; ⑥-Pressure transmitter PT02; ⑦ - Temperature of liquid saturated vapor FX02; ⑧-BPRI02; ⑨-Temperature transmitter TT02; ⑩ - Temperature of liquid saturated vapor FX03; Ⅰ-Exhaust steam regulating valve PV01; Ⅱ-Steam regulating valve PV02; Ⅲ-Desuperheating water regulating valve TV01. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] A highly efficient evaporation system control system, such as Figure 1 As shown, the system includes a crystallizer a, a heater b, a condensate tank c, a condensate pump d, and an axial flow pump e. The crystallizer a has a feed inlet on its lower left side. A gas phase pipeline is connected to the top of the crystallizer a. The lower left side of the crystallizer a, below the feed inlet, is also connected to the bottom of the heater b via a pipeline. The top of the heater b is connected to the middle right side of the crystallizer a via a pipeline. An axial flow pump e is installed on the pipeline connecting the lower part of the crystallizer a to the bottom of the heater b. The lower right side of the heater b is connected to the top of the condensate tank c via a pipeline. The bottom of the condensate tank c is connected to the condensate discharge pipeline via a pipeline. The outlet of the condensate pump d is connected to a condensate discharge pipeline. A steam delivery pipeline is connected to the upper right side of the heater b, and external steam is delivered to the heater b through this pipeline. A steam desuperheating water injection pipeline connects the condensate discharge pipeline and the steam delivery pipeline. A discharge pipeline is connected to the bottom of the crystallizer a.

[0019] Specifically, heater b is a shell-and-tube heater.

[0020] The evaporation process is as follows: The feed liquid enters crystallizer a through the inlet and undergoes forced circulation via axial flow pump e. After being heated by heater b, it returns to crystallizer a. The heated feed liquid undergoes flash evaporation within crystallizer a to generate exhaust steam. This exhaust steam is condensed or reused through the top vapor phase pipeline. The shell side of heater b is heated by steam supplied through a steam delivery pipeline to the tube side of the feed liquid. The condensed steam generates condensate, which enters condensate tank c from the bottom and is then discharged to the outside via condensate pump d. The solution containing crystal particles at the bottom of crystallizer a flows downstream for further processing through its bottom outlet pipeline.

[0021] To better achieve automatic adjustment of the evaporation system, reduce manual operation, and improve system operating efficiency, this utility model adopts the following technical measures: 1. A remote pressure gauge PT01① is installed on the top of crystallizer a, and a waste steam regulating valve PV01Ⅰ is installed on the gas phase pipeline connected to the top of crystallizer a. The temperature of the liquid saturated vapor corresponding to the remote pressure gauge PT01① is calculated using the Antoine formula. The pressure at the top of crystallizer a is adjusted by adjusting the opening of the waste steam regulating valve PV01Ⅰ.

[0022] The control logic for regulating the pressure at the top of the crystallizer is as follows: Antoine's formula: logPT01 = AB / (C + FX01); PT01: Top pressure of the crystallizer, in kPa; FX01: Temperature of the liquid saturated vapor corresponding to PT01 pressure, in °C; A=7.07406, B=1657.46, C=227.02; BPRI01 = TT01 - FX01, where BPRI01③ represents the difference between FX01 and the heater inlet liquid temperature TT01④; When BPRI01>0, the exhaust steam regulating valve I is closed to increase the pressure at the top of crystallizer a, thereby increasing the liquid boiling point FX01② and causing BPRI01 to approach 0; when BPRI01<0, the exhaust steam regulating valve I is opened to decrease the pressure at the top of crystallizer a, thereby decreasing the liquid boiling point FX01② and causing BPRI01 to approach 0.

[0023] The pressure at the top of crystallizer a is usually controlled between -10 kPa and 10 kPa to avoid excessively high or low system pressure, which would affect evaporation efficiency.

[0024] 2. A remote pressure gauge PT03⑤ is installed on the shell side of heater b, and the temperature of the liquid saturated steam corresponding to the remote pressure gauge PT03⑤, FX03 ⑩, is calculated using the Antoine formula. A steam regulating valve PV02 Ⅱ is installed on the steam delivery pipeline, and the pressure on the shell side of heater b is adjusted by adjusting the opening of the steam regulating valve PV02 Ⅱ.

[0025] The heater shell-side pressure control logic is as follows: Antoine's formula: logPT03 = AB / (C + FX03); PT03: Heater shell-side pressure, in kPa; FX03: The temperature of the liquid saturated vapor corresponding to the PT03 pressure, in °C; A=7.07406, B=1657.46, C=227.02 BPRI03=TT01-FX03-△t; △t: Boiling point rise of the solution, which varies depending on the concentration of the solution, and is generally 15 to 20℃.

[0026] When BPRI03>0, the opening of steam regulating valve PV02Ⅱ increases, increasing the steam consumption and increasing the shell-side pressure of heater b, thus causing BPRI03 to approach 0; when BPRI03<0, the opening of steam regulating valve PV02Ⅱ decreases, decreasing the shell-side pressure of heater b, thus causing BPRI03 to approach 0.

[0027] 3. A pressure transmitter PT02⑥ and a temperature transmitter TT02⑨ are sequentially installed on the side of the steam delivery pipeline near heater b, before the steam regulating valve PV02Ⅱ. The temperature transmitter TT02⑨ is located before the steam pipeline desuperheating water injection pipeline, which is closer to the steam regulating valve PV02Ⅱ. A desuperheating water regulating valve TV01Ⅲ is installed on the steam pipeline desuperheating water injection pipeline. The temperature of the liquid saturated steam corresponding to the pressure transmitter PT02⑥, FX02⑦, is calculated using Antoine's formula. The temperature of the steam entering the heater is adjusted by adjusting the opening of the desuperheating water regulating valve TV01Ⅲ to avoid steam oversaturation and affect heat transfer efficiency.

[0028] The control logic for regulating the amount of steam desuperheating water is as follows: Antoine's formula: logPT02 = AB / (C + FX02); PT02: Steam pressure, in kPa; FX02: The temperature of the liquid saturated vapor corresponding to the PTO2 pressure, in °C; A=7.07406, B=1657.46, C=227.02; BPRI02 = TT02 - FX02, where BPRI02⑧ represents the difference between the saturated steam temperature FX02 and the steam temperature TT02. When BPRI02 > 0, it indicates that the steam is oversaturated. Increase the opening of the desuperheating water regulating valve TV01Ⅲ to make BPRI02 approach 0. When BPRI02 ≤ 0, it indicates that the steam is not oversaturated. Close the opening of the desuperheating water regulating valve TV01Ⅲ to make BPRI02 approach 0.

[0029] In this utility model, the exhaust steam regulating valve PV01, the steam regulating valve PV02, and the desuperheating water regulating valve TV01 all adopt pneumatic V-type regulating shut-off valves.

[0030] In this invention, FX01 is connected to the DCS system via programming (according to the Antoni calculation formula) from PT01 and displayed on the central control screen; FX02 and FX03 are similar to FX01. Remote pressure gauges PT01①, PT03⑤, PT02⑤, TT02⑨, and various temperature detectors are also connected to the DCS system.

[0031] This invention installs temperature and pressure remote transmission instruments in crystallizer a, heater b, and key process pipelines to transmit temperature and pressure signals to the DCS system. Through instrument configuration, the measured temperature and pressure are converted into control parameters for the system's regulating valves, thus achieving precise automatic control of the system.

[0032] The above are merely preferred embodiments of this utility model and are not intended to limit or restrict this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection declared by this utility model.

Claims

1. A highly efficient evaporation system control system, including a crystallizer, characterized in that, A remote pressure gauge PT01 is installed on the top of the crystallizer, and a waste steam regulating valve PV01 is installed on the gas phase pipeline connected to the top of the crystallizer. The temperature FX01 of the liquid saturated vapor corresponding to the remote pressure gauge PT01 is calculated by the Antoni formula, and the pressure at the top of the crystallizer is adjusted by adjusting the opening of the waste steam regulating valve PV01.

2. The high-efficiency evaporation system control system according to claim 1, characterized in that, The lower part of one side of the crystallizer is connected to the bottom of the heater via a pipeline, and the top of the heater is connected to the middle of the other side of the crystallizer via a pipeline. An axial flow pump is installed on the pipeline connecting the lower part of the crystallizer to the bottom of the heater. A steam delivery pipeline is connected to the upper part of the side of the heater away from the crystallizer.

3. The high-efficiency evaporation system control system according to claim 2, characterized in that, The heater is a shell-and-tube heater, with a remote pressure gauge PT03 installed on its shell side. A steam regulating valve PV02 is installed on the steam delivery pipeline to calculate the temperature FX03 of the liquid saturated steam corresponding to the remote pressure gauge PT03 using the Antoni formula. The shell-side pressure of the heater is adjusted by adjusting the opening of the steam regulating valve PV02.

4. The high-efficiency evaporation system control system according to claim 3, characterized in that, The lower part of the heater on the side away from the crystallizer is connected to the top of the condensate tank through a pipeline. The condensate tank is equipped with a condensate pump through a pipeline, and the outlet of the condensate pump is connected to a condensate discharge pipeline.

5. The high-efficiency evaporation system control system according to claim 4, characterized in that, The condensate discharge pipeline is connected to the steam transmission pipeline by a steam pipeline desuperheating water injection pipeline. A pressure transmitter PT02 and a temperature transmitter TT02 are sequentially installed on the side of the steam transmission pipeline near the heater, with the temperature transmitter TT02 located before the steam pipeline desuperheating water injection pipeline. The desuperheating water injection line of the steam pipeline is equipped with a desuperheating water regulating valve TV01, which is used to calculate the temperature FX02 of the liquid saturated steam corresponding to the pressure transmitter PT02 using the Antoni formula. The temperature of the steam entering the heater is adjusted by adjusting the opening of the desuperheating water regulating valve TV01 to avoid the steam from becoming oversaturated and affecting the heat transfer efficiency.

6. The high-efficiency evaporation system control system according to claim 5, characterized in that, The crystallizer has a feed inlet on the lower part of the side away from the heater, and a gas phase pipeline is connected to the top of the crystallizer.

7. The high-efficiency evaporation system control system according to claim 6, characterized in that, The exhaust steam regulating valve PV01, steam regulating valve PV02, and desuperheating water regulating valve TV01 are all pneumatic V-type regulating shut-off valves.

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