Cooling system and ammonia distillation device

Abstract

The utility model relates to the technical field of water treatment, in particular to a cooling system and an ammonia distilling device.The cooling system comprises a heat exchanger, a cooling water pipeline and a freezing water pipeline, and the water outlet end of the cooling water pipeline is connected with a water inlet in the heating side of the heat exchanger; the cooling water pipeline comprises a first cooling water branch and a second cooling water branch which are arranged in parallel and can be switched and communicated with each other, a first control valve is arranged on the first cooling water branch, a second control valve is arranged on the second cooling water branch, and the water outlet end of the freezing water pipeline is connected with the second cooling water branch. And a third control valve is arranged on the freezing water pipeline. And different cooling water branches can be switched by adjusting different control valves, so that the cooling requirements of wastewater after ammonia distillation in high-temperature seasons and low-temperature seasons are met at the same time, the use is flexible, and the improvement cost is low.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment, in particular to a cooling system and an ammonia distillation device. Background Art

[0002] The surplus ammonia water generated in the coking process enters the ammonia distillation device after solvent de-phenolization. The wastewater after ammonia distillation goes to biochemical treatment further. Specifically, as Figure 1 shown, the ammonia water after solvent de-phenolization enters the ammonia water adjustment tank 1. The ammonia water in the ammonia water adjustment tank 1 is lifted by the first feed water pump 2 and then enters the inlet and outlet water heat exchange system 3 for heat exchange and temperature rise, and then enters the ammonia distillation tower 4. High-temperature steam is introduced into the ammonia distillation tower 4. The steam takes away most of the volatile ammonia in the wastewater. The wastewater after ammonia distillation is lifted by the second feed water pump 5 and then exchanges heat with the inlet water of the ammonia distillation tower through the inlet and outlet water heat exchange system 3 for preliminary temperature reduction, and then enters the circulating water cooling system 6. In this circulating water cooling system 6, the wastewater is cooled to the temperature required for the subsequent biochemical nitrification reaction and denitrification reaction and then enters the biochemical influent adjustment tank 7. The adjusted wastewater is lifted by the third feed water pump 8 and then enters the subsequent biochemical treatment system.

[0003] The temperature change of the wastewater in the whole system is as follows: The wastewater after solvent de-phenolization is about 35°C. After being heated by the inlet and outlet water heat exchange system 3, it reaches 70°C and enters the ammonia distillation tower 4. It is heated to 100 - 105°C in the ammonia distillation tower 4 for ammonia removal. The wastewater after ammonia removal at about 105°C enters the inlet and outlet water heat exchange system 3 and is cooled to about 70°C and then enters the circulating water cooling system 6. The externally supplied circulating cooling water is 25 - 33°C (affected by winter and summer seasons). The wastewater is cooled to 35°C in the circulating water cooling system 6 and then enters the subsequent biochemical treatment system.

[0004] At present, the following problems exist in the ammonia distillation device:

[0005] 1) In summer, the temperature difference between the circulating cooling water at 33°C and the biochemical influent requirement of 35°C is small. Generally, it cannot reach the required 35°C for entering the biochemical treatment system. Usually, it is at 36 - 37°C. The subsequent biochemical nitrification reaction and denitrification reaction for ammonia removal are inhibited, and the biochemical ammonia removal effect in summer is poor.

[0006] 2) Due to the limitation of the overall supply and distribution of the whole plant, the externally supplied circulating cooling water volume of the circulating water cooling system 6 cannot provide too much additional circulating cooling water.

[0007] 3. According to the requirements, the VOC waste gas generated in the biochemical nitrification reaction and denitrification reaction stages of coking wastewater shall not be discharged without organization. It is necessary to cover and collect the biochemical nitrification reaction and denitrification reaction pools for treatment and then discharge them up to the standard. Covering the pools further causes the temperature of coking wastewater to rise during the treatment process in summer, basically reaching the upper limit (40°C) of the temperature controlled by the biochemical reaction, resulting in extremely poor biochemical ammonia removal effect.

[0008] 4. Currently, fire water is added to the biochemical water tank for cooling. The addition of fire water increases the amount of wastewater treatment in the subsequent section and affects the water balance of the entire system. Moreover, after adding fire water, the C / N / O ratio of the wastewater is affected, and more organic matter needs to be supplemented additionally to assist in ammonia nitrogen removal from the wastewater. Summary of the Invention

[0009] The purpose of the present utility model is to provide a cooling system and an ammonia distillation device to solve the problem that the existing ammonia distillation device cannot meet the requirements of biochemical reactions when using a circulating water cooling system to cool the wastewater after ammonia distillation.

[0010] To achieve the above purpose, the present utility model provides a cooling system, including a heat exchanger, a cooling water pipeline, and a chilled water pipeline. The water outlet end of the cooling water pipeline is connected to the water inlet of the heating side of the heat exchanger. The cooling water pipeline includes a first cooling water branch and a second cooling water branch that are arranged in parallel and can be switched and conducted with each other. A first control valve is provided on the first cooling water branch, a second control valve is provided on the second cooling water branch, the water outlet end of the chilled water pipeline is connected to the second cooling water branch, and a third control valve is provided on the chilled water pipeline.

[0011] Optionally, a refrigeration unit and a chilled water circulation tank are provided on the chilled water pipeline. The chilled water circulation tank is connected to the water outlet of the heating side of the heat exchanger to receive part of the outlet water, and the refrigeration unit is used to refrigerate the water in the chilled water circulation tank.

[0012] Optionally, the water inflow and outflow of the chilled water circulation tank are balanced.

[0013] Optionally, a chilled water circulation pump is provided between the refrigeration unit and the chilled water circulation tank.

[0014] Optionally, the cooling water pipeline is connected to the refrigeration unit through a unit cooling pipeline to cool the refrigeration unit.

[0015] Optionally, a cooling water discharge valve is provided on the unit cooling pipeline.

[0016] Optionally, the water outlet of the heating side of the heat exchanger is also connected to the second cooling water branch through a return water pipeline.

[0017] Optionally, a fourth control valve is provided on the return water pipeline.

[0018] Optionally, a forced circulation pump is provided on the second cooling water branch.

[0019] Based on this, the present utility model further provides an ammonia distillation device, which includes an ammonia distillation tower, an inlet and outlet water heat exchange system, and the cooling system as described above. The inlet and outlet water heat exchange system is used to heat and raise the temperature of the ammonia water entering the ammonia distillation tower and to heat and cool down the wastewater after ammonia distillation discharged from the ammonia distillation tower. The cooling system is used to cool down the wastewater after ammonia distillation that has been heat-exchanged and cooled down.

[0020] The present utility model provides a cooling system and an ammonia distillation device that can switch between two working modes. In the low-temperature season, the temperature of the cooling water supplied by the cooling water pipeline is relatively low, and generally can meet the cooling requirement of the wastewater after ammonia distillation. At this time, the first control valve is opened, and the second control valve and the third control valve are closed simultaneously to switch the cooling water pipeline to the first cooling water branch, and the cooling water is provided to the heat exchanger by the first cooling water branch. In the high-temperature season, the temperature of the cooling water supplied by the cooling water pipeline is relatively high, and generally cannot meet the cooling requirement of the wastewater after ammonia distillation. At this time, the second control valve and the third control valve are opened, and the first control valve is closed simultaneously. The second cooling water branch and the chilled water pipeline supply water at the same time. At this time, the cooling water is mixed with chilled water, and the heat exchange effect can be improved without replacing the heat exchanger to ensure that the temperature reduction of the wastewater after ammonia distillation meets the requirement.

[0021] Therefore, for the cooling system and the ammonia distillation device provided by the present utility model, different cooling water branches can be switched by adjusting different control valves, so as to meet the cooling requirements of the wastewater after ammonia distillation in both the high-temperature season and the low-temperature season at the same time. It is flexible to use and has a low transformation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Those of ordinary skill in the art should understand that the provided drawings are used to better understand the present utility model and do not constitute any limitation to the scope of the present utility model. Among them:

[0023] Figure 1 is a schematic structural diagram of an ammonia distillation device in the prior art;

[0024] Figure 2 is a schematic structural diagram of a cooling system provided by an embodiment of the present utility model;

[0025] Figure 3 is a schematic structural diagram of an ammonia distillation device provided by an embodiment of the present utility model.

[0026] Among them:

[0027] 1 - ammonia water adjustment tank; 2 - first feed water pump; 3 - inlet and outlet water heat exchange system; 4 - ammonia distillation tower; 5 - second feed water pump; 6 - circulating water cooling system; 7 - biochemical influent adjustment tank; 8 - third feed water pump;

[0028] 100 - Cooling system; 200 - Ammonia distillation column; 300 - Inlet and outlet water heat exchange system;

[0029] 101 - Heat exchanger; 102 - First cooling water branch; 103 - Second cooling water branch; 104 - First control valve; 105 - Second control valve; 106 - Chilled water pipeline; 107 - Third control valve; 108 - Refrigeration unit; 109 - Chilled water circulation tank; 110 - Chilled water circulation pump; 111 - Unit cooling pipeline; 112 - Cooling water discharge valve; 113 - Return water pipeline; 114 - Fourth control valve; 115 - Forced circulation pump. Detailed implementation manners

[0030] To make the objectives, advantages and features of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the accompanying drawings are in a very simplified form and use non-precise scales, only for conveniently and clearly assisting in explaining the objectives of the implementation manners of the present utility model. To make the objectives, features and advantages of the present utility model more obvious and understandable, please refer to the accompanying drawings. It should be noted that the structures, scales, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present utility model. Any modification of the structure, change of the proportional relationship or adjustment of the size, in the case of being the same or similar to the effects that the present utility model can produce and the objectives that can be achieved, should still fall within the scope covered by the technical content disclosed by the present utility model.

[0031] As used in the present utility model, the singular forms "a", "an" and "the" include plural objects unless the content clearly indicates otherwise. As used in the present utility model, the term "or" is generally used in the sense of including "and / or" unless the content clearly indicates otherwise. As used in the present utility model, the term "several" is generally used in the sense of including "at least one" unless the content clearly indicates otherwise. As used in the present utility model, the term "at least two" is generally used in the sense of including "two or more" unless the content clearly indicates otherwise. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", "third" may explicitly or implicitly include one or at least two of such features.

[0032] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "installation", "connection", "connection", and "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0033] Please refer to Figure 2 - Figure 3 , this embodiment provides a cooling system 100, including a heat exchanger 101, a cooling water pipeline, and a chilled water pipeline 106. The water outlet end of the cooling water pipeline is connected to the water inlet of the heating-up side of the heat exchanger 101. The cooling water pipeline includes a first cooling water branch 102 and a second cooling water branch 103 that are arranged in parallel and can be switched and conducted with each other. A first control valve 104 is arranged on the first cooling water branch 102, a second control valve 105 is arranged on the second cooling water branch 103, the water outlet end of the chilled water pipeline 106 is connected to the second cooling water branch 103, and a third control valve 107 is arranged on the chilled water pipeline 106.

[0034] The cooling system 100 provided by this embodiment can be switched between two working modes, and its specific working principle is as follows:

[0035] In the low-temperature season, the temperature of the cooling water supplied by the cooling water pipeline is relatively low, generally able to meet the cooling requirements of the wastewater after ammonia distillation. At this time, the first control valve 104 is opened, and at the same time, the second control valve 105 and the third control valve 107 are closed to switch the cooling water pipeline to the first cooling water branch 102, and only the first cooling water branch 102 supplies cooling water to the heat exchanger 101;

[0036] In the high-temperature season, the temperature of the cooling water supplied by the cooling water pipeline is relatively high, generally unable to meet the cooling requirements of the wastewater after ammonia distillation. At this time, the second control valve 105 and the third control valve 107 are opened, and at the same time, the first control valve 104 is closed. The second cooling water branch 103 and the chilled water pipeline 106 supply water at the same time. At this time, the cooling water is mixed with chilled water, and the heat exchange effect can be improved without replacing the heat exchanger 101 to ensure that the temperature of the wastewater after ammonia distillation drops to meet the requirements.

[0037] Therefore, the cooling system 100 provided by the present utility model can switch different cooling water branches by adjusting different control valves, and thus can meet the cooling requirements of the wastewater after ammonia distillation in both high-temperature and low-temperature seasons at the same time, with flexible use and low transformation cost.

[0038] Specifically, a refrigeration unit 108 and a chilled water circulation tank 109 are provided on the chilled water pipeline 106. The chilled water circulation tank 109 is connected to the water outlet of the heating-up side of the heat exchanger 101 to receive part of the outlet water. The refrigeration unit 108 is used to cool the water in the chilled water circulation tank 109. The chilled water circulation tank 109 is used to store chilled water. Most of the outlet water of the heating-up side of the heat exchanger 101 flows to the cooling tower, and after being cooled by the cooling tower, it is recycled back to the cooling water pipeline. A small part of the outlet water of the heating-up side of the heat exchanger 101 enters the chilled water circulation tank 109, is frozen and cooled by the refrigeration unit 108, and then recycled back to the heat exchanger 101.

[0039] Preferably, the water inflow and outflow of the chilled water circulation tank 109 are balanced to achieve the water balance of the chilled water circulation tank 109.

[0040] Preferably, a chilled water circulation pump 110 is provided between the refrigeration unit 108 and the chilled water circulation tank 109. By setting the chilled water circulation pump 110, the refrigeration unit 108, the chilled water circulation pump 110, and the chilled water circulation tank 109 form a self-contained circulation system, ensuring the independence and stability of the operation of the entire refrigeration unit.

[0041] Preferably, the cooling water pipeline is connected to the refrigeration unit 108 through a unit cooling pipeline 111 to cool the refrigeration unit 108, so as to ensure the stability during the operation of the entire refrigeration unit.

[0042] Further, a cooling water discharge valve 112 is provided on the unit cooling pipeline 111. After the cooling water pipeline cools the refrigeration unit 108 through the unit cooling pipeline 111, the cooling water enters the cooling tower through the cooling water discharge valve 112 for treatment, and then is recycled back to the cooling water pipeline.

[0043] Preferably, the water outlet of the heating-up side of the heat exchanger 101 is also connected to the second cooling water branch 103 through a return water pipeline 113. That is to say, part of the outlet water of the heating-up side of the heat exchanger 101 can also be mixed into the cooling water and chilled water through the return water pipeline 113 for recycling, thereby reducing the consumption of cooling water. In this embodiment, part of the return water of the return water pipeline 113 enters the second cooling water branch 103, and part of the return water enters the chilled water circulation tank 109.

[0044] Further, a fourth control valve 114 is provided on the return water pipeline 113 to control the return water volume of the return water pipeline 113. In this embodiment, the first control valve 104, the second control valve 105, the third control valve 107, and the fourth control valve 114 may be on-off valves for controlling the on-off of the pipeline, or may be regulating valves for regulating the flow rate of the pipeline. The present utility model does not limit this. At the same time, each control valve may be a manual valve or an automatic valve, such as an electric valve or a pneumatic valve, which can be selected according to requirements. The present utility model also does not make any limitation on this.

[0045] Preferably, a forced circulation pump 115 is provided on the second cooling water branch 103. Since the cooling water in the second cooling water branch 103 is mixed with the chilled water, in order to maximize heat exchange without replacing the heat exchanger 101, the forced circulation pump 115 may be provided on the second cooling water branch 103 to realize a closed-loop small circulation system of the cooling water inside the heat exchanger 101 and improve the utilization efficiency of the chilled water.

[0046] Based on this, as Figure 3 shown, an embodiment of the present utility model further provides an ammonia distillation device, including an ammonia distillation tower 200, an inlet and outlet water heat exchange system 300, and the cooling system 100 as described above. The inlet and outlet water heat exchange system 300 is used to heat up the ammonia water entering the ammonia distillation tower 200 and cool down the waste water after ammonia distillation discharged from the ammonia distillation tower 200. The cooling system 100 is used to cool down the waste water after ammonia distillation after heat exchange. In this embodiment, the waste water after ammonia distillation enters the cooling side of the cooling system 100 after being cooled down by the inlet and outlet water heat exchange system 300, and the temperature of the waste water after ammonia distillation is further reduced by means of heat exchange, so as to meet the temperature requirements of the subsequent biochemical reaction system and ensure the biochemical ammonia nitrogen removal effect.

[0047] In summary, the embodiment of the present utility model provides a cooling system and an ammonia distillation device. By adjusting different control valves, different cooling water branches can be switched, so as to simultaneously meet the cooling requirements of the waste water after ammonia distillation in high-temperature seasons and low-temperature seasons. It is flexible to use and has a low transformation cost. Moreover, in high-temperature seasons, the temperature of the waste water after ammonia distillation can be further reduced without additionally increasing the external circulating cooling water volume, meeting the temperature required for the subsequent biochemical ammonia nitrogen removal reaction.

[0048] It should also be recognized that although the present utility model has been disclosed above with preferred embodiments, the above embodiments are not intended to limit the present utility model. For any person skilled in the art, without departing from the scope of the technical solution of the present utility model, many possible changes and modifications can be made to the technical solution of the present utility model by using the technical content disclosed above, or it can be modified into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present utility model without departing from the content of the technical solution of the present utility model still belong to the scope of protection of the technical solution of the present utility model.

Claims

1. A cooling system, characterized in that, It includes a heat exchanger, a cooling water pipeline and a chilled water pipeline. The water outlet end of the cooling water pipeline is connected to the water inlet of the heating side of the heat exchanger. The cooling water pipeline includes a first cooling water branch and a second cooling water branch that are arranged in parallel and can be switched and conducted with each other. A first control valve is arranged on the first cooling water branch, and a second control valve is arranged on the second cooling water branch. The water outlet end of the chilled water pipeline is connected to the second cooling water branch, and a third control valve is arranged on the chilled water pipeline.

2. The cooling system according to claim 1, characterized in that, A refrigeration unit and a chilled water circulation tank are arranged on the chilled water pipeline. The chilled water circulation tank is connected to the water outlet of the heating side of the heat exchanger to receive part of the outlet water. The refrigeration unit is used to refrigerate the water in the chilled water circulation tank.

3. The cooling system according to claim 2, characterized in that, The water inflow and outflow of the chilled water circulation tank are balanced.

4. The cooling system according to claim 2, characterized in that, A chilled water circulation pump is arranged between the refrigeration unit and the chilled water circulation tank.

5. The cooling system according to claim 2, wherein The cooling water pipeline is connected to the refrigeration unit through a unit cooling pipeline to cool down the refrigeration unit.

6. The cooling system according to claim 5, characterized in that, A cooling water discharge valve is arranged on the unit cooling pipeline.

7. The cooling system according to claim 1, characterized in that, The water outlet of the heating side of the heat exchanger is also connected to the second cooling water branch through a return water pipeline.

8. The cooling system according to claim 7, characterized in that, A fourth control valve is arranged on the return water pipeline.

9. The cooling system according to claim 1, wherein A forced circulation pump is arranged on the second cooling water branch.

10. An ammonia distillation device, characterized in that, It includes an ammonia distillation tower, an inlet and outlet water heat exchange system and the cooling system according to any one of claims 1-9. The inlet and outlet water heat exchange system is used to heat up the ammonia water entering the ammonia distillation tower and cool down the wastewater after ammonia distillation discharged from the ammonia distillation tower. The cooling system is used to cool down the wastewater after ammonia distillation after heat exchange and cooling.

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