Energy-saving system for recovering heat at top and middle part of cyclohexanol refining tower

Abstract

The utility model discloses a cyclohexanol refining tower top and middle heat recovery energy-saving system, which comprises a cyclohexanol refining tower, a heat recovery device, a cyclohexanol product discharge condenser, a cyclohexane refining tower and the like, a cyclohexanol outlet is arranged in the middle of the cyclohexanol refining tower, the cyclohexanol outlet is connected with a shell pass inlet of the heat recovery device through a pipeline, and the cyclohexanol outlet is connected with a shell pass outlet of the heat recovery device through a pipeline. A shell pass outlet of the heat recovery device is connected with an inlet of a cyclohexanol product discharging condenser through a pipeline, a cyclohexane refining tower 1 # reboiler and a cyclohexane refining tower 2 # reboiler which supply heat to the bottom of the cyclohexane refining tower through a tube pass are arranged at the bottom of the cyclohexane refining tower, and a tube pass inlet of the heat recovery device is connected with a high-purity water pipeline. According to the thermal coupling energy-saving and consumption-reducing device for the cyclohexane refining tower, the thermal coupling energy-saving and consumption-reducing technology is adopted, so that the use amount of circulating water is reduced, the use amount of steam is effectively saved, the production cost can be greatly reduced, and the production efficiency is greatly improved.

Description

Technical Field

[0001] The utility model belongs to the field of energy conservation optimization transformation of chemical steam and condensate, and particularly relates to a heat recovery energy conservation system for the top and middle parts of a cyclohexanol refining tower. Background Technique

[0002] The cyclohexanol device of Henan Shenma Nylon Chemical Co., Ltd. mainly uses partial hydrogenation of benzene to prepare cyclohexene, and cyclohexene is then hydrated to prepare cyclohexanol. Through years of research and transformation on potential tapping and efficiency improvement, an invention patent (CN202010204383.X) for a high-quality cyclohexanol production device and process has been developed, obtaining complete independent intellectual property rights. The production capacity of the device has increased from less than 100,000 tons per year initially to about 200,000 tons per year. With the rapid development of China's chemical industry, the demand for cyclohexanol has also increased rapidly, and the market prospect is broad. However, with the increase in domestic production capacity, currently, the main competition is on cost. Energy conservation and emission reduction is a basic national policy of China and an inevitable choice for realizing the sustainable development of China's economy. As a major energy-consuming industry, the chemical production industry should pay more attention to this issue. This requires enterprises to make efforts in energy conservation and consumption reduction to improve the market competitiveness of enterprises.

[0003] In the cyclohexanol production process, on the one hand, the gaseous cyclohexene and part of cyclohexanol coming out of the top of the cyclohexanol refining tower need to be cooled by a condenser and then returned to the reflux drum, which requires a large amount of condensate. On the other hand, the gaseous cyclohexanol product coming out of the middle of the cyclohexanol refining tower also has relatively high heat that is not fully utilized. It needs to be cooled by a condenser and then transported to the cyclohexanol product storage tank. Since the product cyclohexanol still has a relatively high temperature of 50°C after passing through the condenser, it is easy to cause scale formation inside the condenser, and more seriously, it affects the safety of the cyclohexanol product storage tank. In the past transformation, the gaseous discharge from the middle of the cyclohexanol refining tower was directly used to heat the reboiler of the cyclohexane refining tower through heat exchange. However, some problems were also found during the operation process. Since the two streams of materials are heat-exchanged in the same reboiler, in case of leakage, it will affect the quality of the two products. Therefore, it is urgent to implement energy conservation technical transformation on the cyclohexanol refining tower to achieve energy conservation and consumption reduction of the cyclohexanol production device. Content of the Utility Model

[0004] The purpose of the utility model is to solve the problems existing in the above background. A heat recovery energy conservation system for the top and middle parts of a cyclohexanol refining tower is provided. By adopting heat recovery technology, the heat of the gaseous cyclohexene at the top is directly returned to the cyclohexanol separation tower for recovery and utilization, and the heat of the gaseous cyclohexanol product in the middle of the cyclohexanol refining tower is indirectly used as the heat source of the cyclohexane refining tower reboiler for recovery and utilization. Thus, the steam amount of the reboiler can be effectively saved and the circulating water amount of the top gaseous condenser can be reduced. The optimized operation and energy conservation and consumption reduction of the cyclohexanol refining tower are realized.

[0005] To achieve the above object, the specific solution adopted by the present utility model is as follows:

[0006] A heat recovery and energy-saving system for the top and middle parts of a cyclohexanol refining tower, comprising a cyclohexanol refining tower, a heat recovery device, a cyclohexanol product discharge condenser, a cyclohexanol refining tower condenser, a cyclohexanol refining tower reflux drum, a cyclohexanol separation tower, a cyclohexane refining tower, a cyclohexane refining tower condenser and a cyclohexane refining tower reflux drum. A heavy component discharge pipeline and a cyclohexanol refining tower reboiler for heating the bottom of the cyclohexanol refining tower are provided at the bottom of the cyclohexanol refining tower. A cyclohexanol outlet is provided in the middle of the cyclohexanol refining tower. The cyclohexanol outlet is connected to the shell-side inlet of the heat recovery device through a pipeline. The shell-side outlet of the heat recovery device is connected to the inlet of the cyclohexanol product discharge condenser through a pipeline. The outlet of the cyclohexanol product discharge condenser is connected with a cyclohexanol discharge pipeline. A cyclohexane discharge pipeline and a cyclohexane refining tower 1# reboiler and a cyclohexane refining tower 2# reboiler for heating the bottom of the cyclohexane refining tower through the tube side are provided at the bottom of the cyclohexane refining tower. The tube-side inlet of the heat recovery device is connected to a high-purity water pipeline. The tube-side outlet of the heat recovery device is connected to the shell side of the cyclohexane refining tower 1# reboiler through a pipeline.

[0007] Further, two branches are provided at the top outlet of the cyclohexanol refining tower. One branch is connected to the cyclohexanol separation tower, and the other branch is connected to the cyclohexanol refining tower reflux drum through the cyclohexanol refining tower condenser. The outlet of the cyclohexanol refining tower reflux drum is connected to the upper reflux port of the cyclohexanol refining tower through a cyclohexanol refining tower reflux pipeline.

[0008] Further, the top outlet pipeline of the cyclohexane refining tower is connected to the cyclohexane refining tower reflux drum through the cyclohexane refining tower condenser. The outlet of the cyclohexane refining tower reflux drum is connected to the upper reflux port of the cyclohexane refining tower through a cyclohexane refining tower reflux pipeline. A sampling pipeline is branched on the cyclohexane refining tower reflux pipeline.

[0009] Further, a cyclohexanol refining tower bottom pump is provided on the heavy component discharge pipeline.

[0010] Further, a cyclohexanol refining tower discharge pump is provided on the cyclohexanol discharge pipeline.

[0011] Further, a cyclohexanol refining tower reflux pump is provided on the cyclohexanol refining tower reflux pipeline.

[0012] Further, a cyclohexane refining tower bottom pump is provided on the cyclohexane discharge pipeline.

[0013] Further, a cyclohexane refining tower reflux pump is provided on the cyclohexane refining tower reflux pipeline.

[0014] By applying heat recovery technology, the utility model reduces the amount of circulating water used and effectively saves the amount of steam used, which can greatly reduce production costs, significantly improve production efficiency, enable chemical plants to have more output value, and meet the production needs of the chemical industry. Brief Description of the Drawings

[0015] Figure 1 It is a structural schematic diagram of the utility model.

[0016] In the figure: 1, cyclohexanol refining tower; 2, cyclohexanol refining tower reboiler; 3, cyclohexanol refining tower bottom pump; 4, heat recovery device; 5, cyclohexanol product discharge condenser; 6, cyclohexanol refining tower discharge pump; 7, cyclohexanol refining tower condenser; 8, cyclohexanol refining tower reflux drum; 9, cyclohexanol refining tower reflux pump; 10, cyclohexanol separation tower; 11, cyclohexane refining tower; 12, cyclohexane refining tower No. 1 reboiler; 13, cyclohexane refining tower bottom pump; 14, cyclohexane refining tower No. 2 reboiler; 15, cyclohexane refining tower condenser; 16, cyclohexane refining tower reflux drum; 17, cyclohexane refining tower reflux pump; WC, condensate inlet; WCR, condensate return; CCH, high-temperature condensate; CCL, low-temperature condensate; SH, high-pressure steam; SL, low-pressure steam; WPH, high-purity water. Specific Embodiments

[0017] The following further describes the utility model with reference to the drawings.

[0018] Embodiment 1

[0019] A heat recovery and energy-saving system for the top and middle parts of a cyclohexanol refining tower, as Figure 1As shown in the figure, it includes a cyclohexanol refining tower 1, a heat recovery device 4, a cyclohexanol product discharge condenser 5, a cyclohexanol refining tower condenser 7, a cyclohexanol refining tower reflux drum 8, a cyclohexanol separation tower 10, a cyclohexane refining tower 11, a cyclohexane refining tower condenser 15, and a cyclohexane refining tower reflux drum 16. At the bottom of the cyclohexanol refining tower 1, there are a heavy component discharge pipeline and a cyclohexanol refining tower reboiler 2 for heating the bottom of the cyclohexanol refining tower 1. On the heavy component discharge pipeline, there are a cyclohexanol refining tower bottom pump 3 and a heavy component discharge valve. In the middle of the cyclohexanol refining tower 1, there is a cyclohexanol outlet, which is connected to the shell side inlet of the heat recovery device 4 through a pipeline. The shell side outlet of the heat recovery device 4 is connected to the inlet of the cyclohexanol product discharge condenser 5 through a pipeline. The outlet of the cyclohexanol product discharge condenser 5 is connected to a cyclohexanol discharge pipeline, and on the cyclohexanol discharge pipeline, there are a cyclohexanol refining tower discharge pump 6 and a cyclohexanol discharge valve. At the top of the cyclohexanol refining tower 1, there is a low-boiling point substance outlet pipeline, and the low-boiling point substance outlet pipeline has two branches. One branch is connected to the cyclohexanol separation tower 10, and the other branch is connected to the cyclohexanol refining tower reflux drum 8 through the cyclohexanol refining tower condenser 7. The outlet of the cyclohexanol refining tower reflux drum 8 is connected to the upper part of the cyclohexanol refining tower 1 through a cyclohexanol refining tower reflux pipeline. On the cyclohexanol refining tower reflux pipeline, there are a cyclohexanol refining tower reflux pump 9 and a cyclohexanol refining tower reflux control valve.

[0020] At the bottom of the cyclohexane refining tower 11, there are a cyclohexane discharge pipeline, a cyclohexane refining tower 1# reboiler 12 and a cyclohexane refining tower 2# reboiler 14 for heating the bottom of the cyclohexane refining tower 11 through the tube side. On the cyclohexane discharge pipeline, there are a cyclohexane refining tower bottom pump 13 and a cyclohexane discharge valve. The tube side inlet of the heat recovery device 4 is connected to a high-purity water pipeline, and the tube side outlet of the heat recovery device 4 is connected to the shell side of the cyclohexane refining tower 1# reboiler 12 through a pipeline and a valve provided on the pipeline. At the top of the cyclohexane refining tower 11, there is a low-boiling point substance outlet pipeline, and the low-boiling point substance outlet pipeline is connected to the cyclohexane refining tower reflux drum 16 through the cyclohexane refining tower condenser 15. The outlet of the cyclohexane refining tower reflux drum 16 is connected to the reflux port of the upper part of the cyclohexane refining tower 11 through a reflux pipeline and a cyclohexane refining tower reflux pump 17 provided on the pipeline. A sampling pipeline is branched on the reflux pipeline.

[0021] Actual working process: The materials in the cyclohexanol refining tower 1 include cyclohexanol, cyclohexene, trace heavy components, and light component impurities. The heat for these components is provided by the cyclohexanol refining tower reboiler 2 in the cyclohexanol refining tower 1. A part of the low-boiling substances at the top of the tower is condensed by the cyclohexanol refining tower condenser 7 and stored in the cyclohexanol refining tower reflux drum 8. The oil components in the cyclohexanol refining tower reflux drum 8 are refluxed into the cyclohexanol refining tower 1 through the cyclohexanol refining tower reflux pump 9 to control the stability of the top components, and the other part is directly returned to the cyclohexanol separation tower 10. The heavy component materials at the bottom of the cyclohexanol refining tower 1 are regularly discharged and recovered through the cyclohexanol refining tower bottom pump 3. The refined cyclohexanol product in the middle of the cyclohexanol refining tower 1 escapes in the form of steam, first passes through the heat recovery device 4 for heat recovery, the condensed cyclohexanol product is further heat-exchanged through the cyclohexanol product discharge condenser 5, and finally is transported to the cyclohexanol product storage tank for storage through the cyclohexanol refining tower discharge pump 6. The heat recovery device 4 uses the high-purity water WPH generated by the device as a medium and becomes low-pressure steam after heat exchange. The low-pressure steam generated by the heat recovery device 4 is supplied as the heat source for the cyclohexane refining tower 1# reboiler. The cyclohexane refining tower can be heated by the cyclohexane refining tower 1# reboiler 12 or the cyclohexane refining tower 2# reboiler 14. During normal operation, the low-pressure steam generated by the heat recovery of the cyclohexane refining tower 1# reboiler 12 is used as the heat source. When the heat recovery unit stops working or the heat provided by the cyclohexane refining tower 1# reboiler 12 is insufficient, the heat source can be provided by the cyclohexane refining tower 2# reboiler 14 without affecting the normal operation of the cyclohexane refining tower 11. The low-boiling substances at the top of the cyclohexane refining tower 11 are condensed by the cyclohexane refining tower condenser 15 and stored in the cyclohexanol refining tower reflux drum 16. A part of the light components in the cyclohexanol refining tower reflux drum 16 are refluxed into the cyclohexane refining tower 11 through the cyclohexanol refining tower reflux pump 17 to control the stability of the top components, and the other part of the light components are sent out and recovered. The cyclohexane product materials at the bottom of the cyclohexane refining tower 11 are sent to the cyclohexane product storage tank through the cyclohexane refining tower bottom pump 13.

[0022] Finally, it should be noted that the above embodiments are only used to illustrate the specific implementation technical solutions of the present invention rather than to limit it. Those of ordinary skill in the art should understand that any equivalent substitution or obvious modification of the implementation manner of the present invention without changing its performance or use should be covered within the scope of protection claimed by the present invention.

Claims

1. A heat recovery and energy saving system for the top and middle parts of a cyclohexanol refining tower, characterized in that, It includes a cyclohexanol refining tower, a heat recovery device, a cyclohexanol product discharge condenser, a cyclohexanol refining tower condenser, a cyclohexanol refining tower reflux drum, a cyclohexanol separation tower, a cyclohexane refining tower, a cyclohexane refining tower condenser and a cyclohexane refining tower reflux drum. A heavy component discharge pipeline and a cyclohexanol refining tower reboiler for heating the bottom of the cyclohexanol refining tower are provided at the bottom of the cyclohexanol refining tower. A cyclohexanol outlet is provided in the middle of the cyclohexanol refining tower. The cyclohexanol outlet is connected to the shell side inlet of the heat recovery device through a pipeline. The shell side outlet of the heat recovery device is connected to the inlet of the cyclohexanol product discharge condenser through a pipeline. The outlet of the cyclohexanol product discharge condenser is connected with a cyclohexanol discharge pipeline. A cyclohexane discharge pipeline and a cyclohexane refining tower 1# reboiler and a cyclohexane refining tower 2# reboiler for heating the bottom of the cyclohexane refining tower through the tube side are provided at the bottom of the cyclohexane refining tower. The tube side inlet of the heat recovery device is connected to a high-purity water pipeline. The tube side outlet of the heat recovery device is connected to the shell side of the cyclohexane refining tower 1# reboiler through a pipeline.

2. The energy-saving system for heat recovery at the top and middle of the cyclohexanol refining tower according to claim 1, characterized in that, Two branches are provided at the top outlet of the cyclohexanol refining tower. One branch is connected to the cyclohexanol separation tower, and the other branch is connected to the cyclohexanol refining tower reflux drum through the cyclohexanol refining tower condenser. The outlet of the cyclohexanol refining tower reflux drum is connected to the reflux port at the upper part of the cyclohexanol refining tower through the cyclohexanol refining tower reflux pipeline.

3. The heat recovery and energy saving system for the top and middle parts of the cyclohexanol refining tower according to claim 1, wherein The pipeline at the top outlet of the cyclohexane refining tower is connected to the cyclohexane refining tower reflux drum through the cyclohexane refining tower condenser. The outlet of the cyclohexane refining tower reflux drum is connected to the reflux port at the upper part of the cyclohexane refining tower through the cyclohexane refining tower reflux pipeline. A sampling pipeline is provided as a branch on the cyclohexane refining tower reflux pipeline.

4. The heat recovery and energy saving system for the top and middle parts of the cyclohexanol refining tower according to claim 1, characterized in that, A cyclohexanol refining tower bottom pump is provided on the heavy component discharge pipeline.

5. The heat recovery and energy saving system for the top and middle parts of the cyclohexanol refining tower according to claim 1, wherein A cyclohexanol refining tower discharge pump is provided on the cyclohexanol discharge pipeline.

6. The heat recovery and energy saving system for the top and middle parts of the cyclohexanol refining tower according to claim 1, wherein A cyclohexanol refining tower reflux pump is provided on the cyclohexanol refining tower reflux pipeline.

7. The heat recovery and energy saving system for the top and middle parts of the cyclohexanol refining tower according to claim 1, characterized in that, A cyclohexane refining tower bottom pump is provided on the cyclohexane discharge pipeline.

8. The heat recovery and energy saving system for the top and middle parts of the cyclohexanol refining tower according to claim 1, characterized in that, A cyclohexane refining tower reflux pump is provided on the cyclohexane refining tower reflux pipeline.

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