A high-efficiency transfer and recycling system for DMF synthesis reaction heat

Abstract

The utility model discloses a kind of DMF synthetic reaction heat efficient transfer and recycling recovery system, including reactor, synthetic heat exchanger, desalted water circulating pump, raw water preheater, desalted water tank and synthetic circulating pump.According to the prior art, the utility model provides a kind of DMF synthetic reaction heat efficient transfer and recycling recovery system, including reactor, synthetic heat exchanger, desalted water circulating pump, raw water preheater, desalted water tank and synthetic circulating pump.The reactor is communicated with the synthetic heat exchanger by circulation pipeline, and the synthetic heat exchanger is communicated with desalted water tank by the raw water preheater;Desalted water tank is communicated with synthetic heat exchanger;The synthetic circulating pump is arranged on the connecting pipeline between the tube pass of synthetic heat exchanger and reactor.The desalted water circulating pump is arranged on the connecting pipeline between desalted water tank and the shell side of synthetic heat exchanger.The utility model absorbs and transports to raw water preheater inside synthetic heat exchanger reaction heat, to heat raw water in raw water preheater, avoid energy waste caused by heat direct discharge, improve the energy efficiency and economy of entire system.

Description

Technical Field

[0001] This utility model belongs to the field of heat energy recovery technology in chemical production, specifically relating to a DMF synthesis reaction heat efficient transfer and reuse recovery system. Background Technology

[0002] Currently, 80% of DMF industrial production facilities use a one-step carbon monoxide process, which uses dimethylamine and carbon monoxide as raw materials and sodium methoxide as a catalyst to directly synthesize dimethylformamide under certain temperature and pressure conditions. The reaction is exothermic, so a large amount of heat is released during the process. Effective measures need to be taken during production to remove the heat of reaction in a timely manner, otherwise it will cause overheating in the reactor.

[0003] In existing DMF production units, the heat of reaction is mainly transferred to the demineralized water via heat exchangers. The demineralized water then needs to be cooled with cooling water to prevent it from becoming overheated and losing its ability to absorb the heat of reaction. This results in the direct release of heat from the demineralized water, leading to a waste of thermal energy.

[0004] Furthermore, in current DMF production, temperature control is primarily achieved by adjusting the demineralized water flow rate in the synthesis heat exchanger. This leads to frequent temperature fluctuations in the demineralized water, increasing the difficulty of process control. However, without frequent adjustments to the demineralized water flow rate, large temperature variations in the demineralized water tank would occur, consequently making the synthesis temperature even more difficult to control. On the other hand, if the temperature of the demineralized water tank is controlled by adjusting the circulating water flow rate in the demineralized water cooler, the risk of scaling is higher when the circulating water flow rate is low. Utility Model Content

[0005] This invention addresses the shortcomings of existing technologies by providing a highly efficient DMF synthesis reaction heat transfer and reuse recovery system, comprising a reactor, a synthesis heat exchanger, a demineralized water circulation pump, a raw water preheater, a demineralized water tank, and a synthesis circulation pump.

[0006] The reactor is connected to the tube side of the synthesis heat exchanger via a circulation pipeline. The shell-side outlet of the synthesis heat exchanger is connected to the inlet of the demineralized water tank via the raw water preheater. The outlet of the demineralized water tank is connected to the shell-side inlet of the synthesis heat exchanger. The tube side and shell side of the synthesis heat exchanger are not connected to each other and heat exchange occurs through the tube walls.

[0007] The synthesis circulation pump is installed on the connecting pipeline between the tube side of the synthesis heat exchanger and the reactor.

[0008] The demineralized water circulation pump is installed on the connecting pipeline between the demineralized water tank and the shell side of the synthesis heat exchanger.

[0009] Furthermore, the shell side of the raw water preheater supplies demineralized water from the demineralized water tank, while the tube side supplies external raw water; heat exchange occurs between the shell side and the tube side of the raw water preheater through the tube wall.

[0010] Furthermore, the reactor is equipped with a temperature sensor, and the demineralized water circulation pump is an electrically controlled circulation pump; the temperature sensor is connected to a PLC controller for data transmission, and the PLC controller is connected to the control signal input terminal of the demineralized water circulation pump for signal transmission.

[0011] Furthermore, a connecting branch line is provided on the pipeline connecting the synthesis heat exchanger and the raw water preheater, and the outlet end of the connecting branch line is connected to the pipeline connecting the raw water preheater and the demineralized water tank.

[0012] Along the flow direction, a third switching valve is provided on the pipeline connecting the synthesis heat exchanger and the raw water preheater after the inlet of the secondary line; a fourth switching valve is provided on the secondary line.

[0013] Furthermore, the outlet end of the demineralized water circulation pump is provided with a reflux pipe, and the outlet end of the reflux pipe is connected to the inlet end of the demineralized water tank; a first switch valve is provided on the reflux pipe, and a second switch valve is provided on the pipeline between the outlet end of the demineralized water tank and the shell-side inlet end of the synthesis heat exchanger.

[0014] This utility model has at least one of the following advantages:

[0015] 1. This utility model uses a demineralized water circulation pump to drive the demineralized water to circulate between the synthesis heat exchanger and the raw water preheating system, thereby absorbing the reaction heat inside the synthesis heat exchanger and transporting it to the raw water preheater, thus heating the raw water in the raw water preheater, avoiding direct heat discharge and energy waste, and improving the energy efficiency and economy of the entire system.

[0016] 2. This utility model heats the raw water by introducing demineralized water into the raw water preheater. In other words, the heat energy obtained from the heat exchange of demineralized water is used to heat the raw water. Therefore, the raw water flow rate does not need to be controlled, thereby reducing the risk of scaling. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system structure of this utility model.

[0018] In the diagram: 1. Reactor; 2. Synthesis heat exchanger; 3. Demineralized water circulation pump; 4. Raw water preheater; 5. Demineralized water tank; 6. Synthesis circulation pump; 7. Sub-line; 8. Return pipe. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the scope of the present utility model.

[0020] This utility model provides an exemplary system for the efficient transfer and recycling of the heat of DMF synthesis reaction, such as... Figure 1 As shown: It includes reactor 1, synthesis heat exchanger 2, demineralized water circulation pump 3, raw water preheater 4, demineralized water tank 5, and synthesis circulation pump 6.

[0021] The reactor 1 is connected to the tube side of the synthesis heat exchanger 2 via a circulation pipeline. The shell-side outlet of the synthesis heat exchanger 2 is connected to the inlet of the demineralized water tank 5 via the raw water preheater 4. The outlet of the demineralized water tank 5 is connected to the shell-side inlet of the synthesis heat exchanger 2. The tube side and shell side of the synthesis heat exchanger 2 are not connected to each other, and heat exchange occurs through the tube walls. The tube side of the synthesis heat exchanger 2 consists of the pipeline section inside the heat exchanger, while the shell side consists of fluid channels located inside the outer shell. The tube walls of the pipelines are in pressure contact with the inner wall of the outer shell, thereby achieving heat exchange through the tube walls.

[0022] The synthesis circulation pump 6 is installed on the connecting pipeline between the tube side of the synthesis heat exchanger 2 and the reactor 1.

[0023] The demineralized water circulation pump 3 is installed on the connecting pipeline between the demineralized water tank 5 and the shell side of the synthesis heat exchanger 2.

[0024] The device operates as follows: First, the operator inputs CO and dimethylamine into reactor 1 at a preset molar ratio, controlling the internal temperature and pressure of reactor 1 to reach the preset reaction temperature and pressure, for example: temperature 110-115℃, pressure 1.6-1.7MPa. Then, the synthesis circulation pump 6 is started, driving the synthesis reaction liquid inside reactor 1 to circulate between the tube side of the synthesis heat exchanger 2 and reactor 1. Simultaneously, the demineralized water circulation pump 3 is started, delivering demineralized water to the shell side of the synthesis heat exchanger 2, where heat exchange with the tube side raises the temperature of the demineralized water, for example, from 50℃ to 100℃. The demineralized water, having absorbed heat, enters the raw water preheater 4 to heat the raw water, for example, preheating it to 20-30℃. The demineralized water, after heat exchange, then re-enters the demineralized water tank 5. The preheated raw water can be used in subsequent equipment that requires hot water, thereby saving the heat required to heat the raw water and realizing the effective reuse of reaction heat energy.

[0025] This invention utilizes a combination of a synthesis heat exchanger 2, a raw water preheater 4, and a demineralized water circulation pump 3. The demineralized water circulation pump 3 drives the demineralized water to circulate between the synthesis heat exchanger 2 and the raw water preheating system, thereby absorbing the reaction heat inside the synthesis heat exchanger 2 and transporting it to the raw water preheater 4. This heats the raw water in the raw water preheater 4, avoiding direct heat discharge and energy waste, and improving the energy efficiency and economy of the entire system.

[0026] This utility model provides an exemplary raw water preheater 4. The shell side of the raw water preheater 4 supplies demineralized water from the demineralized water tank 5, while the tube side supplies external raw water. Heat exchange occurs between the shell side and the tube side of the raw water preheater 4 through the tube wall. This configuration enables continuous heating of flowing raw water. The tube side of the raw water preheater 4 consists of the pipeline section within the preheater, while the shell side is a fluid channel located inside the outer shell. The tube wall of the pipeline is in pressure contact with the inner wall of the outer shell, thereby achieving heat exchange through the tube wall.

[0027] At this point, when the demineralized water, having absorbed heat, enters the raw water preheater 4, it passes through the shell side of the preheater 4, while the raw water passes through the tube side. This allows the high-temperature demineralized water to exchange heat with the low-temperature raw water within the preheater 4, heating the raw water while simultaneously reducing the amount of demineralized water. At this stage, the raw water flow rate does not need to be controlled, meaning a large flow rate of raw water can be introduced, thereby reducing the risk of scaling.

[0028] This utility model provides a reactor 1, which is equipped with a temperature sensor inside. The demineralized water circulation pump 3 is an electrically controlled circulation pump. The temperature sensor is connected to a PLC controller, and the PLC controller is connected to the control signal input terminal of the demineralized water circulation pump 3.

[0029] At this time, the temperature of the synthesis reaction liquid inside reactor 1 is monitored in real time by a temperature sensor, and the flow rate of demineralized water is adjusted accordingly by regulating the flow rate of the demineralized water circulation pump 3. This, in turn, regulates the heat exchange rate between the demineralized water and the synthesis reaction liquid in the synthesis heat exchanger 2, thereby controlling the temperature of the synthesis reaction liquid. For example, when the temperature of the synthesis reaction liquid inside reactor 1 is low, the flow rate of the demineralized water circulation pump 3 is reduced to decrease the heat exchange rate in the synthesis heat exchanger 2, thus reducing the amount of heat removed from the synthesis reaction liquid and achieving temperature control of the synthesis reaction liquid using the heat of reaction.

[0030] This utility model provides an exemplary pipeline installation, such as... Figure 1 As shown, a connecting branch line 7 is provided on the pipeline connecting the synthesis heat exchanger 2 and the raw water preheater 4. The outlet end of the connecting branch line 7 is connected to the pipeline connecting the raw water preheater 4 and the demineralized water tank 5.

[0031] Along the flow direction, a third switching valve is provided on the pipeline connecting the synthesis heat exchanger 2 and the raw water preheater 4 after the inlet of the secondary line 7; a fourth switching valve is provided on the secondary line 7.

[0032] At this point, by adjusting the opening and closing of the third and fourth switching valves to control whether the demineralized water passes through the raw water preheater 4, the demineralized water supply temperature of the synthesis heat exchanger 2 can be adjusted. For example, when the demineralized water temperature is too low, the third switching valve can be closed and the fourth switching valve can be opened, so that the demineralized water no longer heats the raw water but flows directly back to the demineralized water tank 5, thus preventing the demineralized water from continuing to cool down.

[0033] This utility model provides an exemplary pipeline installation, such as... Figure 1 As shown, the outlet end of the demineralized water circulation pump 3 is provided with a reflux pipe 8, and the outlet end of the reflux pipe 8 is connected to the inlet end of the demineralized water tank 5; a first switch valve is provided on the reflux pipe 8, and a second switch valve is provided on the pipeline between the outlet end of the demineralized water tank 5 and the shell-side inlet end of the synthesis heat exchanger 2.

[0034] To avoid frequent changes in the output power of the demineralized water circulation pump 3, this setting allows the demineralized water output by the demineralized water circulation pump 3 to flow to the synthesis heat exchanger 2 and directly back to the demineralized water tank 5 in different proportions by adjusting the opening of the first and second switching valves, thereby achieving the regulation of the demineralized water flow rate in the synthesis heat exchanger 2.

[0035] It should be noted and understood that various modifications and improvements can be made to the present invention as described in the above description without departing from the spirit and scope of the claims. Therefore, the scope of the claimed technical solutions is not limited to any specific exemplary teachings given.

Claims

1. A system for efficient transfer and recycling of the heat of DMF synthesis reaction, characterized in that, It includes a reactor (1), a synthesis heat exchanger (2), a demineralized water circulation pump (3), a raw water preheater (4), a demineralized water tank (5), and a synthesis circulation pump (6); The reactor (1) is connected to the tube side of the synthesis heat exchanger (2) through a circulation pipeline. The shell side outlet of the synthesis heat exchanger (2) is connected to the inlet of the demineralized water tank (5) through the raw water preheater (4). The outlet of the demineralized water tank (5) is connected to the shell side inlet of the synthesis heat exchanger (2). The tube side and shell side of the synthesis heat exchanger (2) are not connected to each other and heat exchange occurs through the tube wall. The synthesis circulation pump (6) is installed on the connecting pipeline between the tube side of the synthesis heat exchanger (2) and the reactor (1); The demineralized water circulation pump (3) is installed on the connecting pipeline between the demineralized water tank (5) and the shell side of the synthesis heat exchanger (2).

2. The DMF synthesis reaction heat high-efficiency transfer and reuse recovery system according to claim 1, characterized in that, The shell side of the raw water preheater (4) is supplied with demineralized water, and the tube side of the raw water preheater (4) is supplied with external raw water. Heat exchange occurs between the shell side and the tube side of the raw water preheater (4) through the tube wall.

3. The DMF synthesis reaction heat high-efficiency transfer and reuse recovery system according to claim 1, characterized in that, The reactor (1) is equipped with a temperature sensor, and the demineralized water circulation pump (3) is an electrically controlled circulation pump; the temperature sensor is connected to the PLC controller, and the PLC controller is connected to the control signal input terminal of the demineralized water circulation pump (3).

4. The DMF synthesis reaction heat high-efficiency transfer and reuse recovery system according to claim 1, characterized in that, A connecting branch line (7) is provided on the pipeline connecting the synthesis heat exchanger (2) and the raw water preheater (4). The outlet end of the connecting branch line (7) is connected to the pipeline connecting the raw water preheater (4) and the demineralized water tank (5). Along the flow direction, the pipeline connecting the synthesis heat exchanger (2) and the raw water preheater (4) is provided with a third switch valve after the inlet of the sub-line (7); a fourth switch valve is provided on the sub-line (7).

5. The DMF synthesis reaction heat high-efficiency transfer and reuse recovery system according to claim 1, characterized in that, The outlet end of the demineralized water circulation pump (3) is provided with a reflux pipe (8), and the outlet end of the reflux pipe (8) is connected to the inlet end of the demineralized water tank (5); a first switch valve is provided on the reflux pipe (8), and a second switch valve is provided on the pipeline between the outlet end of the demineralized water tank (5) and the shell-side inlet end of the synthesis heat exchanger (2).

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