Ammonia distillation waste heat utilization system
By using waste hot water in the ammonia distillation system to cool the ammonia fractionator and a first-stage wastewater cooler, and using a refrigeration unit to recover waste heat to produce low-temperature water, the problem of unutilized waste heat in the traditional ammonia distillation process is solved, achieving energy conservation and consumption reduction.
Patent Information
- Application Number
- CN202422602091.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-28
- Publication Date
- 2025-10-17
- Estimated Expiration
- 2034-10-28
AI Technical Summary
In the traditional ammonia distillation process, the heat of ammonia vapor at the top of the ammonia distillation tower and the heat of ammonia distillation wastewater at the bottom of the ammonia distillation tower are not effectively recovered and utilized, resulting in energy waste and unreasonable energy utilization, affecting the energy conservation and emission reduction of the ammonia distillation system.
Waste hot water is used instead of circulating water to cool the ammonia fractionator and the first stage wastewater cooler, and the refrigeration unit is used to recover waste heat to produce low-temperature water, replacing the steam double-effect lithium bromide absorption chiller to reduce the consumption of circulating water and steam.
The waste heat is effectively utilized, the circulating water consumption and steam consumption of the entire plant are reduced, energy is saved and equipment investment is reduced.
Smart Images
Figure CN223445276U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a kind of ammonia evaporation waste heat utilization systems. The ammonia evaporation system inside ammonia fractionator, one section waste water cooler waste heat is used as heat source to produce low temperature water, for ammonia evaporation system inside ammonia condensing cooler, two section waste water cooler. BACKGROUND
[0002] The traditional ammonia evaporation process is as follows: the remaining ammonia water from the tar ammonia water separation process enters the ammonia water heat exchanger, exchanges heat with the ammonia evaporation wastewater discharged from the bottom of the ammonia evaporation tower, and enters the ammonia evaporation tower. The bottom part of the ammonia evaporation wastewater is indirectly heated by the steam reboiler, and the generated steam returns to the bottom as the heat source for ammonia evaporation. The ammonia vapor at the top of the ammonia evaporation tower is cooled by the ammonia fractionator, then condensed into concentrated ammonia water by the ammonia condensing cooler, and sent out. The condensed liquid from the ammonia fractionator flows back to the ammonia evaporation tower directly. The ammonia fractionator is cooled by circulating water. The ammonia evaporation wastewater from the bottom is pumped out by the ammonia evaporation wastewater pump, exchanges heat with the remaining ammonia water in the ammonia water heat exchanger, then cools down by the first section waste water cooler and the second section waste water cooler, and is sent to the sewage treatment. The ammonia fractionator and the first section waste water cooler are cooled by circulating water, and the ammonia condensing cooler and the second section waste water cooler are cooled by low temperature water.
[0003] In the above heat exchange process, the ammonia vapor heat in the ammonia fractionator at the top of the ammonia evaporation tower and the ammonia evaporation wastewater heat in the first section waste water cooler at the bottom of the ammonia evaporation tower are cooled by circulating cooling water, without considering heat recovery and utilization, resulting in waste of energy and not conducive to energy saving and emission reduction of the ammonia evaporation system. The ammonia condensing cooler and the second section waste water cooler need low temperature water for cooling, which requires additional heat to produce low temperature water. Therefore, the waste heat in the traditional ammonia evaporation process is not recycled and utilized, resulting in energy waste, and the internal energy of the ammonia evaporation system is not utilized reasonably, which is not conducive to energy saving and emission reduction of the ammonia evaporation system.
[0004] In summary, how to improve the utilization of waste heat in the ammonia evaporation system is a problem that needs to be solved urgently in the ammonia evaporation system. Utility model content
[0005] To solve the above problems, the utility model provides an ammonia evaporation waste heat utilization system to recover the ammonia vapor heat at the top of the ammonia evaporation tower and the ammonia evaporation wastewater heat at the bottom of the ammonia evaporation tower to produce low temperature water for the ammonia condensing cooler and the second section waste water cooler. It mainly consists of an ammonia evaporation tower, an ammonia fractionator, an ammonia water heat exchanger, a first section waste water cooler, a second section waste water cooler, a refrigeration unit, a waste heat water pump, and an ammonia condensing cooler. The recovered waste heat is used for low temperature water type lithium bromide absorption type cold water unit, replacing steam double-effect lithium bromide absorption type cold water unit, saving circulating cooling water and steam consumption, so as to achieve the purpose of energy saving and consumption reduction.
[0006] To achieve the above purpose, the utility model adopts the following technical solutions:
[0007] The waste heat water outlet of the ammonia decomposer and the waste heat water outlet of the first-stage waste water cooler are connected with the waste heat water inlet of the refrigerating unit through pipes; the waste heat water outlet of the refrigerating unit is connected with the waste heat water inlet of the ammonia decomposer and the waste heat water inlet of the first-stage waste water cooler through a waste heat water pump.
[0008] Further, the ammonia decomposer and the first-stage waste water cooler are cooled by waste heat water instead of circulating cooling water, thereby reducing the circulating water consumption.
[0009] Further, the refrigerating unit is a low-temperature hot water type lithium bromide absorption type cold water unit instead of a steam double-effect lithium bromide absorption type cold water unit, thereby reducing the steam consumption.
[0010] Further, the ammonia condensing cooler and the second-stage waste water cooler are cooled by two-stage cooling, and are cooled by circulating water and low-temperature water respectively; the low-temperature water is produced by the internal waste heat of the ammonia evaporation system.
[0011] The utility model discloses the beneficial effects are: on one hand, waste heat water replaces circulating water and cools the heat medium of ammonia decomposer and first-stage waste water cooler, reduces the circulating water consumption of whole factory, and further reduces the electric power consumption of circulating water treatment, saves energy.
[0012] On the other hand, waste heat water replaces circulating cooling water and recovers the waste heat in ammonia decomposer and first-stage waste water cooler, and the generated waste heat water is sent to the low-temperature hot water type lithium bromide absorption type cold water unit together with the waste heat water of the primary cooler, without additional equipment investment. The low-temperature water produced by the internal waste heat of the ammonia evaporation system reduces the treatment scale of the steam double-effect lithium bromide absorption type cold water unit, thereby reducing the steam consumption. BRIEF DESCRIPTION OF DRAWINGS
[0013] Figure 1 The utility model provides a kind of structure schematic diagram of ammonia evaporation waste heat utilization system. In the figure: 1 ammonia tower, 2 ammonia decomposer, 3 ammonia water heat exchanger, 4 first-stage waste water cooler, 5 second-stage waste water cooler, 6 refrigerating unit, 7 waste heat water pump, 8 ammonia condensing cooler DETAILED DESCRIPTION
[0014] In order to deepen the understanding of the utility model, the utility model will be further described in the following embodiment, and the embodiment is only used to explain the utility model, and does not constitute the limitation to the protection scope of the utility model.
[0015] Figure 1The utility model provides a kind of ammonia evaporation waste heat utilization system's structural diagram, including ammonia evaporation tower, ammonia separator, ammonia water heat exchanger, one section wastewater cooler, two section wastewater cooler, refrigerating unit, waste heat water pump, ammonia condensing cooler.
[0016] Specifically, ammonia separator 2 and one section wastewater cooler 4 are originally cooled using 33-43 DEG C circulating cooling water, and the treatment of circulating cooling water requires additional increase in the treatment scale and cost of circulating cooling water. After the about 103 DEG C ammonia vapor at the top of ammonia evaporation tower 1 is cooled by ammonia separator 2, it is directly returned to ammonia evaporation tower 1, and ammonia separator 2 produces about 73 DEG C waste heat water. The ammonia evaporation wastewater at the bottom of the tower, about 108 DEG C, is pumped out by ammonia evaporation wastewater pump, and after heat exchange with the remaining ammonia water in ammonia water heat exchanger 3, the ammonia evaporation wastewater is cooled to about 90 DEG C. After heat exchange in one section wastewater cooler 4, about 73 DEG C waste heat water is produced. The waste heat water produced by ammonia separator 2, the waste heat water produced by one section wastewater cooler 4 and the waste heat water produced by the upper section of the primary cooler are combined and sent to low-temperature hot water type lithium bromide absorption type cold water unit 6 to produce low-temperature water. The about 63 DEG C waste heat water after use of low-temperature hot water type lithium bromide absorption type cold water unit 6 is sent to ammonia separator 2, one section wastewater cooler 4 and the upper section of the primary cooler by waste heat water pump 7.
[0017] The low-temperature water inlets of the low-temperature water sections of ammonia condensing cooler 8 and two section wastewater cooler 5 are respectively connected to the low-temperature water outlet of refrigerating unit 6. The low-temperature water outlets of the low-temperature water sections of ammonia condensing cooler 8 and two section wastewater cooler 5 are respectively connected to the low-temperature water inlet of refrigerating unit 6. Ammonia condensing cooler 8 and two section wastewater cooler 5 themselves need to use low-temperature water for cooling, and the use of waste heat in the ammonia evaporation system to produce low-temperature water reduces production cost.
[0018] The above-described embodiments are merely descriptions of the embodiments of the utility model, and do not limit the concept and scope of the utility model. Various modifications and improvements to the technical solutions of the utility model made by those skilled in the art without departing from the design concept of the utility model shall fall within the protection scope of the utility model.
Claims
1. An ammonia evaporation waste heat utilization system, characterized by: It includes an ammonia distillation tower, an ammonia fractionator, an ammonia water heat exchanger, a first-stage wastewater cooler, a second-stage wastewater cooler, a refrigeration unit, a waste heat water pump, and an ammonia condensation cooler; the waste heat water outlets of the ammonia fractionator and the first-stage wastewater cooler are connected to the waste heat water inlet of the refrigeration unit; the waste heat water inlets of the ammonia fractionator and the first-stage wastewater cooler are connected to the outlet of the refrigeration unit through the waste heat water pump; the low-temperature water inlet and outlet of the second-stage wastewater cooler and the ammonia condensation cooler are connected to the low-temperature water outlet and inlet of the refrigeration unit respectively.
2. The ammonia evaporation waste heat utilization system according to claim 1, characterized in that: The ammonia fractionator and the first stage wastewater cooler are cooled by waste hot water.
3. The ammonia evaporation waste heat utilization system according to claim 1, characterized in that: The refrigeration unit adopts a low-temperature hot water type lithium bromide absorption chiller.
4. The ammonia evaporation waste heat utilization system according to claim 1, characterized in that: The ammonia condensing cooler and the second-stage wastewater cooler adopt two-stage cooling, using circulating water and low-temperature water for cooling respectively; the low-temperature water is produced by the waste heat inside the ammonia distillation system.