阅读说明：本技术 放热反应工序的温度控制系统 (Temperature control system for exothermic reaction process ) 是由 陈恩之 姜曦 徐淑媛 赵风轩 张传礼 谢毅 于彬 杨建新 于 2019-10-21 设计创作，主要内容包括：一种放热反应工序的温度控制系统,包括驱动泵、第一热交换器、第二热交换器、流量控制器,第一热交换器的冷却介质进口通过管路与驱动泵的出口连接,冷却介质出口通过管路与第二热交换器的被冷却介质进口连接,第二热交换器的被冷却介质出口通过管路与驱动泵的进口连接,形成一个封闭循环线路,流量控制器串联在封闭循环线路上,还包括一应急旁开管路或压力式溢流阀,应急旁开管路的上游端与流量控制器的进口并联,下游端与流量控制器的出口并联,应急旁开管路的流通面积为流量控制器的流通面积的1/9-1/2,压力式溢流阀的进口与流量控制器的进口并联,出口与流量控制器的出口并联。本发明结构简单、可靠性高,有效满足放热反应工序中安全生产的需要。(A temperature control system for an exothermic reaction process comprises a driving pump, a first heat exchanger, a second heat exchanger and a flow controller, wherein a cooling medium inlet of the first heat exchanger is connected with an outlet of the driving pump through a pipeline, a cooling medium outlet is connected with a cooled medium inlet of the second heat exchanger through a pipeline, a cooled medium outlet of the second heat exchanger is connected with an inlet of the driving pump through a pipeline to form a closed circulation line, the flow controller is connected on the closed circulation line in series, the temperature control system also comprises an emergency bypass pipeline or a pressure type overflow valve, the upstream end of the emergency bypass pipeline is connected with an inlet of the flow controller in parallel, the downstream end of the emergency bypass pipeline is connected with an outlet of the flow controller in parallel, the flow area of the emergency bypass pipeline is 1/9-1/2 of the flow area of the flow controller, an inlet of the pressure type overflow valve is connected with an inlet, the outlet is connected in parallel with the outlet of the flow controller. The invention has simple structure and high reliability, and effectively meets the requirement of safe production in the exothermic reaction process.)

1. A temperature control system for an exothermic reaction process, comprising: comprises a driving pump (1), a first heat exchanger (2), a second heat exchanger (3) and a flow controller (4),

the first heat exchanger (2) is used for absorbing heat of an exothermic reaction process, the second heat exchanger (3) is used for releasing heat to the outside,

the cooling medium inlet of the first heat exchanger (2) is connected with the outlet of the driving pump (1) through a pipeline, the cooling medium outlet of the first heat exchanger (2) is connected with the cooled medium inlet of the second heat exchanger (3) through a pipeline, the cooled medium outlet of the second heat exchanger (3) is connected with the inlet of the driving pump (1) through a pipeline to form a closed circulation circuit,

the flow controller (4) is connected in series on the closed circulation line and is used for adjusting the circulation flow of the closed circulation line,

the emergency bypass pipeline is characterized by further comprising an emergency bypass pipeline (5) or a pressure type overflow valve (6), wherein the upstream end of the emergency bypass pipeline (5) is connected with the inlet of the flow controller (4) in parallel, the downstream end of the emergency bypass pipeline (5) is connected with the outlet of the flow controller (4) in parallel, the flow area of the emergency bypass pipeline (5) is 1/9-1/2 of the flow area of the flow controller (4), the inlet of the pressure type overflow valve (6) is connected with the inlet of the flow controller (4) in parallel, and the outlet of the pressure type overflow valve (6) is connected with the outlet of the flow controller (4) in parallel.

2. The system for controlling temperature of an exothermic reaction process according to claim 1, wherein: the first heat exchanger (2) is a coiled pipe, the upstream end of the coiled pipe is a cooling medium inlet, and the downstream end of the coiled pipe is a cooling medium outlet.

3. The system for controlling temperature of an exothermic reaction process according to claim 1, wherein: the second heat exchanger (3) is a plate heat exchanger and/or a tube heat exchanger.

4. The system for controlling temperature of an exothermic reaction process according to claim 1, wherein: the flow controller (4) is a flow regulating valve.

5. The system for controlling temperature of an exothermic reaction process according to claim 1, wherein: and a flow-limiting orifice plate is arranged in the emergency bypass pipeline (5), and the flow area of the flow-limiting orifice plate is 1/9-1/2 of the flow area of the flow controller (4).

6. The system for controlling temperature of an exothermic reaction process according to claim 1, wherein: a cooling medium expansion tank is connected in series between the cooled medium outlet of the second heat exchanger (3) and the inlet of the driving pump (1).

7. The system for controlling temperature of an exothermic reaction process according to claim 1, wherein: the inlet of the flow controller (4) is connected with the cooling medium outlet of the first heat exchanger (2) through a pipeline, and the outlet of the flow controller (4) is connected with the cooled medium inlet of the second heat exchanger (3) through a pipeline.

8. The system for controlling temperature of an exothermic reaction process according to claim 7, wherein: the upstream end of the emergency bypass pipeline (5) is connected in parallel between the cooling medium outlet of the first heat exchanger (2) and the inlet of the flow controller (4), and the downstream end of the emergency bypass pipeline (5) is connected in parallel between the outlet of the flow controller (4) and the cooled medium inlet of the second heat exchanger (3).

Technical Field

The invention relates to the field of chemical industry, in particular to a temperature control system for an exothermic reaction process.

Background

In the chemical field, an exothermic reaction process is involved, and the temperature of the process needs to be strictly controlled and kept in a proper range so as to ensure that the reaction is normally carried out.

For example, the production of adipic acid. Adipic acid belongs to aliphatic carboxylic acid, commonly called as adipic acid, and has a molecular formula of C₆H₁₀O₄The appearance is white crystal powder, the property is stable, and the deliquescence is avoided. The product is mainly used for preparing nylon 66 (nylon 66) and polyurethane resin, and then is used for preparing plasticizer and lubricating grease, and is used as acid increasing agent for food in small amount and used for replacing tartaric acid to prepare baking powder, and also can be used for preparing pesticide and adhesive, and the adipic acid is also used for producing medicine, perfume, etc. At present, the industries with fast increase of the domestic use amount comprise the resin industry for synthetic leather, the polyurethane sole resin industry, the polyurethane adhesive and the polyol industry for TPU. There are four methods of adipic acid production in the world today: phenol, butadiene, cyclohexane and cyclohexene processes. The cyclohexane method and the cyclohexene method are mature and are main production methods. The four methods for producing adipic acid are to oxidize cyclohexanol or cyclohexanol/cyclohexanone mixture with nitric acid, commonly called nitric acid oxidation method。

Crude acid generated after nitric acid oxidation reaction enters a crude acid crystallizer for adiabatic cooling evaporation, the crystallized crude acid slurry is thickened and centrifuged by the crude acid, then solid-liquid separation is carried out to obtain crude adipic acid, and the crude adipic acid is dissolved and decolored and then sent to an industrial acid crystallizer. And thickening, centrifuging, dissolving and decoloring the crystallized slurry again to obtain the industrial grade adipic acid. And crystallizing, thickening and centrifuging the industrial-grade adipic acid, and then drying the industrial-grade adipic acid in a fluidized bed to obtain the product of refined adipic acid. Nitrous gas generated by oxidation is absorbed by a nitrogen oxide absorption post to produce dilute nitric acid, and the thickened filtrate is concentrated by nitric acid and then recovered. The dibasic acid is evaporated twice, washed twice with resin, evaporated, sliced and packaged to obtain the byproduct dibasic acid. The catalyst is recycled and enters the system again after being subjected to resin adsorption twice.

In the adipic acid production process, the heat release of the nitric acid oxidation reaction process is large, so that the nitric acid oxidation reaction process adopts circulating water for cooling, and the circulating amount of cooling water is controlled by controlling the opening of a regulating valve on a circulating water path so as to control the temperature of the reaction process. However, if the regulating valve is closed due to a fault, the flow rate of the circulating water is greatly reduced, even is zero, and the reaction heat cannot be removed in time, so that the oxidation reaction temperature is out of control.

Therefore, how to design a safe and reliable temperature control system for exothermic reaction process is a problem to be solved urgently by those skilled in the art.

Disclosure of Invention

The invention aims to provide a temperature control system for an exothermic reaction process, which has a simple structure and high reliability and effectively meets the requirement of safe production in the exothermic reaction process, aiming at the defects of the prior art.

The technical scheme of the invention is as follows: a temperature control system of an exothermic reaction process comprises a driving pump, a first heat exchanger, a second heat exchanger and a flow controller, wherein the first heat exchanger is used for absorbing heat of the exothermic reaction process, the second heat exchanger is used for releasing heat to the outside, a cooling medium inlet of the first heat exchanger is connected with an outlet of the driving pump through a pipeline, a cooling medium outlet of the first heat exchanger is connected with a cooled medium inlet of the second heat exchanger through a pipeline, a cooled medium outlet of the second heat exchanger is connected with an inlet of the driving pump through a pipeline to form a closed circulation circuit, the flow controller is connected with the closed circulation circuit in series and used for adjusting circulation flow of the closed circulation circuit, the temperature control system further comprises an emergency bypass pipeline or a pressure type overflow valve, and the upstream end of the emergency bypass pipeline is connected with an inlet of the flow controller in parallel, the downstream end of the emergency bypass pipeline is connected with the outlet of the flow controller in parallel, the flow area of the emergency bypass pipeline is 1/9-1/2 of the flow area of the flow controller, the inlet of the pressure type overflow valve is connected with the inlet of the flow controller in parallel, and the outlet of the pressure overflow valve is connected with the outlet of the flow controller in parallel.

The first heat exchanger is a coiled pipe, the upstream end of the coiled pipe is a cooling medium inlet, and the downstream end of the coiled pipe is a cooling medium outlet.

The second heat exchanger is a plate heat exchanger and/or a tube heat exchanger.

The flow controller is a flow regulating valve.

And a flow-limiting orifice plate is arranged in the emergency bypass pipeline, and the flow area of the flow-limiting orifice plate is 1/9-1/2 of the flow area of the flow controller.

And a cooling medium expansion tank is connected in series between the cooled medium outlet of the second heat exchanger and the inlet of the driving pump.

The inlet of the flow controller is connected with the cooling medium outlet of the first heat exchanger through a pipeline, and the outlet of the flow controller is connected with the cooled medium inlet of the second heat exchanger through a pipeline.

The upstream end of the emergency bypass pipeline is connected between the cooling medium outlet of the first heat exchanger and the inlet of the flow controller in parallel, and the downstream end of the emergency bypass pipeline is connected between the outlet of the flow controller and the cooled medium inlet of the second heat exchanger in parallel.

Adopt above-mentioned technical scheme to have following beneficial effect:

1. the first heat exchanger is used for absorbing heat in an exothermic reaction process and reducing the temperature of the exothermic reaction process, and the second heat exchanger is used for releasing heat to the outside and reducing the temperature of a medium in the closed circulation circuit, so that the heat released in the exothermic reaction process is released quickly, and the requirement of safe production in the exothermic reaction process is met. The flow of the medium in the closed circulation line is adjusted by adjusting the opening of the flow controller, so that the requirement for adjusting the temperature of the exothermic reaction process is met.

2. The invention can set an emergency bypass pipeline, the upstream end of the emergency bypass pipeline is connected in parallel with the inlet of the flow controller, the downstream end of the emergency bypass pipeline is connected in parallel with the outlet of the flow controller, when the flow controller is in a full-closed or nearly full-closed state due to faults (including self faults of the flow controller or faults of the controller controlling the flow controller, etc.) or artificial misoperation, the medium in the closed circulation line keeps part of the medium to normally circulate through the emergency bypass pipeline, thereby effectively slowing down the temperature rise amplitude of the exothermic reaction process, increasing the correction time of working personnel and realizing the safe and controllable fault state.

3. The flow area of the emergency bypass pipeline which can be arranged in the invention is 1/9-1/2 of the flow area of the flow controller, and on the premise of meeting the normal circulation of part of the medium in the closed circulation line in an emergency state, the flow controller can be regulated to control the medium flow of the closed circulation line, so that the requirement of regulating the temperature of the exothermic reaction process is met. If the flow area of the emergency bypass pipeline is too small, the purpose of emergency circulation cannot be achieved, and if the flow area of the emergency bypass pipeline is too large, the requirement for adjusting the temperature of the exothermic reaction process cannot be met.

4. The inlet of the pressure type overflow valve which can be arranged in the invention is connected with the inlet of the flow controller in parallel, the outlet of the pressure overflow valve is connected with the outlet of the flow controller in parallel, when the flow controller works normally, the medium in the closed circulation line passes normally along the flow controller, and the flow of the medium in the closed circulation line is adjusted by the flow controller. When the flow controller is in a full-closed or nearly full-closed state due to faults (including the self fault of the flow controller, the fault of the controller controlling the flow controller and the like) or manual misoperation, the pressure of a medium in the closed circulating pipeline is increased, after the pressure exceeds the opening pressure of the pressure type overflow valve, the pressure type overflow valve is opened, the medium in the closed circulating pipeline keeps normal circulation of the medium through the pressure type overflow valve, the temperature rise amplitude of an exothermic reaction process is effectively reduced, the correction time of workers is increased, and the safe and controllable fault state is realized.

The following further description is made with reference to the accompanying drawings and detailed description.

Drawings

FIG. 1 is a schematic connection diagram of the present invention;

fig. 2 is a schematic connection diagram of the pressure type overflow valve of the invention.

In the attached drawing, 1 is a driving pump, 2 is a first heat exchanger, 3 is a second heat exchanger, 4 is a flow controller, 5 is an emergency bypass pipeline, and 6 is a pressure type overflow valve.

Detailed Description

In the invention, equipment with no specific connection mode is generally carried out according to conventional conditions or conditions suggested by manufacturers, and equipment with a specific model is generally conventional equipment in the chemical field.