Cooling system for long-period operation of discharged ash water in coal chemical industry

Abstract

The utility model discloses a coal chemical industry discharge ash water long-period operation cooling system which is characterized by comprising a vacuum flash tank, a recycling branch and a discharge branch, the recycling branch comprises a first settling tank, a first grey water tank and a slag flushing system; the vacuum flash tank is sequentially connected with the first settling tank, the first grey water tank and the slag flushing system through a recycling pipeline; the discharge branch comprises a heat exchanger, a second settling tank, a second grey water tank and a biochemical treatment system, the heat exchanger is connected with a circulating water system, and the vacuum flash tank is sequentially connected with the heat exchanger, the second settling tank, the second grey water tank and the biochemical treatment system through a discharge pipeline.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the heat exchange field, concretely relates to a coal chemical industry ash water long period operation cooling system. BACKGROUND

[0002] The production process of coal chemical enterprise can produce gasification black water, and the gasification black water contains a large amount of large particle impurities, which needs to be treated before being discharged. The existing treatment method is usually as follows: first, the black water is introduced into the vacuum flash tank, and then the black water is introduced into the settling tank after being flashed, and then the black water is introduced into the clarifier after being settled, at this time, the black water becomes clear, and the temperature is about 70 DEG C. The industry insiders call it "ash water", and the clarifier where it is located is also called "ash water tank". One of the ash water is recycled, and the other is introduced into the heat exchanger to reduce the temperature. The ash water is cooled to below 40 DEG C and then discharged to the downstream biochemical system. The cooling method of the discharged ash water selects the conventional heat exchanger for direct cooling, but the ash water contains a large amount of calcium and magnesium ions, which is easy to scale, and the scaling period is short, which is 10-15 days, and the longest is not more than two months. In order to prevent scaling, workers add a large amount of dispersing agent between the settling tank and the ash water tank, but the effect is not obvious. The frequent scaling problem troubles every coal chemical enterprise. The heat exchange effect of the heat exchanger after the structure is not up to standard, and the heat exchanger is easy to be blocked. Therefore, the enterprise needs to spend a lot of cleaning cost to clean the heat exchanger every year. CONTENT OF THE UTILITY MODEL

[0003] In order to solve the above problems, the utility model provides a coal chemical industry ash water long period operation cooling system, which is characterized by comprising a vacuum flash tank, a recycling branch and an external discharge branch.

[0004] The recycling branch comprises a first settling tank, a first ash water tank and a slag flushing system; the vacuum flash tank is connected with the first settling tank, the first ash water tank and the slag flushing system in sequence through a recycling pipeline.

[0005] The external discharge branch comprises a heat exchanger, a second settling tank, a second ash water tank and a biochemical treatment system, the heat exchanger is connected with a circulating water system, and the vacuum flash tank is connected with the heat exchanger, the second settling tank, the second ash water tank and the biochemical treatment system in sequence through an external discharge pipeline.

[0006] The black water is directly introduced into the heat exchanger for cooling, and then the black water is settled to become ash water and is discharged into the biochemical treatment system. Since the black water contains a large amount of large particle impurities, the black water can flush the scale in the heat exchanger when being introduced into the heat exchanger. The scale in the heat exchanger can be removed by the continuous flow of the black water, and the scaling period can be prolonged from the longest two months to one year, which greatly prolongs the scaling period.

[0007] Further, the heat exchanger comprises a black water inlet and a black water outlet, a first external discharge pipe section is connected between the vacuum flash tank and the black water inlet, and a second external discharge pipe section is connected between the black water outlet and the second settling tank.

[0008] Further, the first outer discharge pipe section is provided with a water pump, a water inlet valve and a first flow meter; the second outer discharge pipe section is provided with a water outlet valve and a second flow meter.

[0009] The flow rate of the black water into the heat exchanger is controlled by the cooperation of the water pump and the water inlet valve.

[0010] Further, the rotating speed of the water pump has at least two gears, A and B, the rotating speed of the A gear is greater than that of the B gear, the water inlet valve has at least two gears, C and D, the pipe diameter of the C gear is smaller than that of the D gear, the water pump and the water inlet valve cooperate to form at least two different flow rates of the black water into the heat exchanger.

[0011] When there is no scale, the flow rate of the black water into the black water inlet is set according to the heat exchange requirement, the first flow meter records the flow rate at the black water inlet, and the flow rate at the black water outlet is recorded by the second flow meter; when the flow rate of the black water into the black water inlet is unchanged and the flow rate value recorded by the second flow meter decreases, it indicates that there is scale in the heat exchanger; when the value of the second flow meter is about to affect the use, the rotating speed of the water pump is increased, and the gear of the water inlet valve is adjusted accordingly to increase the flow rate of the black water, so that the impact of the black water on the scale in the heat exchanger is increased to reduce the scale; when the scale is reduced, the value of the second flow meter increases, and when it increases to the normal value, the gears of the water pump and the water inlet valve can be adjusted back to prevent the black water from causing excessive impact on the wall of the heat exchanger, thereby reducing the service life of the heat exchanger.

[0012] Further, a controller is further included, the controller is connected with the water pump, the water inlet valve, the first flow meter and the second flow meter; the display value of the first flow meter is E, the display value of the second flow meter is F, a threshold value G is set for the second flow meter, and when F is less than G, the controller controls the water pump and the water inlet valve to adjust the gears to increase the value of E.

[0013] The controller can be set to automatically control and adjust the gears of the water pump and the water inlet valve, and the threshold value G is the value of the second flow meter when the scale in the heat exchanger is about to affect the use.

[0014] Further, a formula for calculating the scale scouring degree caused by the change of the black water flow rate is calculated according to the influence of the change of the black water flow rate on the flow rate of the second flow meter, the controller adjusts the water pump and the water inlet valve in real time according to the feedback of the second flow meter, the flow rate of the second flow meter is kept constant, and the scale in the heat exchanger is cleaned in time.

[0015] Further, the water inlet valve is a vortex valve, so that the black water into the heat exchanger forms a vortex to increase the scouring force of the black water on the scale and improve the scale cleaning efficiency.

[0016] Further, the first outer discharge pipe section and the second outer discharge pipe section are both provided with a thermometer.

[0017] Further, the first outer discharge pipe section and the water inlet valve are detachably connected, so that when the water inlet valve is blocked, the water inlet valve can be easily dredged and maintained.

[0018] Further, the circulating water system comprises a cold medium pipe and a hot medium pipe, and the heat exchanger further comprises a cold medium inlet and a hot medium outlet; the cold medium pipe is connected with the cold medium inlet, and the hot medium pipe is connected with the hot medium outlet.

[0019] Further, the cold medium pipe and the hot medium pipe are both provided with valves.

[0020] The heat exchanger of the present application has the following beneficial effects:

[0021] (1) The heat exchanger of the present application greatly delays the fouling period of the heat exchanger, reduces the number of times of cleaning the heat exchanger, and prolongs the service life of the heat exchanger.

[0022] (2) The heat exchanger of the present application reduces the number of times of cleaning the heat exchanger, saves a large amount of cleaning funds, and reduces the production cost.

[0023] (3) The heat exchanger of the present application is not easy to be blocked, reduces the influence on production caused by the blockage of the heat exchanger, and improves the production efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present application, and form a part of the present application. The schematic embodiments of the present application and the description thereof are used to explain the present application, and do not constitute an improper limitation on the present application.

[0025] Figure 1 The present application is a structural schematic diagram of an embodiment of the present application.

[0026] In the drawings: 1-vacuum flash tank, 2-recycling branch, 21-first settling tank, 22-first grey water tank, 23-slag flushing system, 3-outer discharge branch, 31-first outer discharge pipe section, 311-water pump, 312-water inlet valve, 313-first flow meter, 32-heat exchanger, 321-black water inlet, 322-black water outlet, 33-second outer discharge pipe section, 331-water outlet valve, 332-second flow meter, 34-second settling tank, 35-second grey water tank, 36-biochemical treatment system, 4-circulating water system, 41-cold medium pipe, 42-hot medium pipe. DETAILED DESCRIPTION

[0027] In order to more clearly illustrate the overall concept of the present application, the following will be described in detail in an exemplary manner with reference to the drawings.

[0028] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other manners different from the description herein, and therefore, the protective scope of the present application is not limited to the specific embodiments disclosed below.

[0029] In addition, in the description of the present application, it should be understood that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0030] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected, or it can be communicated; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0031] In the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0032] A coal chemical industry effluent ash water long-period operation cooling system, characterized by comprising a vacuum flash tank 1, a recycling branch 2 and an effluent branch 3.

[0033] The recycling branch 2 comprises a first sedimentation tank 21, a first ash water tank 22 and a slag flushing system 23; the vacuum flash tank 1 is connected with the first sedimentation tank 21, the first ash water tank 22 and the slag flushing system 23 in sequence through a recycling pipeline;

[0034] The outer discharge branch 3 comprises a heat exchanger 32, a second settling tank 34, a second grey water tank 35 and a biochemical treatment system 36, the heat exchanger 32 is connected with the circulating water system 4, and the vacuum flash tank 1 is sequentially connected with the heat exchanger 32, the second settling tank 34, the second grey water tank 35 and the biochemical treatment system 36 through the outer discharge pipeline.

[0035] The black water is directly used to cool the heat exchanger 32, and the black water is changed into the grey water after being cooled and then being settled and being discharged into the biochemical treatment system 36. Since the black water contains many large-particle impurities, the black water entering the heat exchanger 32 can flush the scale in the heat exchanger 32. The scale in the heat exchanger 32 can be removed by the continuous high flow rate of the black water, and the scale forming period can be prolonged from the longest two months to one year, which greatly delays the scale forming period.

[0036] Further, the heat exchanger 32 comprises a black water inlet 321 and a black water outlet 322, the first outer discharge pipeline section 31 is connected between the vacuum flash tank 1 and the black water inlet 321, and the second outer discharge pipeline section 33 is connected between the black water outlet 322 and the second settling tank 34.

[0037] Further, the first outer discharge pipeline section 31 is provided with a water pump 311, a water inlet valve 312 and a first flow meter 313, and the second outer discharge pipeline section 33 is provided with a water outlet valve 331 and a second flow meter 332.

[0038] The flow rate of the black water entering the heat exchanger 32 is controlled by the cooperation of the water pump 311 and the water inlet valve 312.

[0039] Further, the water pump 311 has at least two gears A and B, the rotation speed of the gear A is greater than that of the gear B, the water inlet valve 312 has at least two gears C and D, the pipe diameter of the gear C is smaller than that of the gear D, and the water pump 311 and the water inlet valve 312 are cooperated to form at least two different flow rates of the black water entering the heat exchanger 32.

[0040] When there is no scale, the flow rate of the black water entering the black water inlet is set according to the heat exchange requirement, the flow rate of the black water inlet is recorded by the first flow meter 313, and the flow rate of the black water outlet 322 is recorded by the second flow meter 332. When the flow rate of the black water entering the black water inlet is unchanged and the flow rate value recorded by the second flow meter 332 is reduced, it indicates that the heat exchanger 32 has scale. When the value of the second flow meter 332 is reduced to the point that it will affect the use, the rotation speed of the water pump 311 is increased, and the gear of the water inlet valve 312 is adjusted accordingly, so as to increase the flow rate of the black water, increase the impact of the black water on the scale in the heat exchanger 32, and reduce the scale. When the scale is reduced, the value of the second flow meter 332 is increased, and when the value is increased to the normal value, the gears of the water pump 311 and the water inlet valve 312 can be adjusted back, so as to prevent the black water from excessively impacting the pipe wall of the heat exchanger 32, and further reduce the service life of the heat exchanger 32.

[0041] Furthermore, it also includes a controller, which is connected to the water pump 311, the inlet valve 312, the first flow meter 313, and the second flow meter 332. The first flow meter 313 displays a value of E, and the second flow meter 332 displays a value of F. A threshold value of G is set for the second flow meter 332. When F is less than G, the controller controls the water pump 311 and the inlet valve 312 to adjust their gears so that the value of E increases.

[0042] The controller can be set to automatically adjust the speed of the water pump 311 and the inlet valve 312. The threshold G is the value of the second flow meter 332 when the scale inside the heat exchanger 32 will affect the use, as determined in advance by testing.

[0043] Furthermore, based on the effect of changing the flow rate of the black water on the flow rate of the second flow meter 332, a formula is calculated to determine the degree of scale scouring caused by the change in the flow rate of the black water. The controller adjusts the water pump 311 and the inlet valve 312 in real time based on the feedback from the second flow meter 332 to achieve a constant flow rate of the second flow meter 332, thereby ensuring timely cleaning of the scale inside the heat exchanger 32.

[0044] Furthermore, the inlet valve 312 is a vortex valve, which causes the black water entering the heat exchanger 32 to form a vortex, thereby increasing the flushing force of the black water on the scale and improving the scale removal efficiency.

[0045] Furthermore, both the first external discharge pipe section 31 and the second external discharge pipe section 33 are equipped with thermometers.

[0046] Furthermore, the first external drain pipe section 31 and the inlet valve 312 are detachably connected, which facilitates unblocking and maintenance when the inlet valve 312 is blocked.

[0047] Furthermore, the circulating water system 4 includes a refrigerant pipe 41 and a heat transfer pipe 42, and the heat exchanger 32 also includes a refrigerant inlet and a heat transfer outlet; the refrigerant pipe 41 is connected to the refrigerant inlet, and the heat transfer pipe 42 is connected to the heat transfer outlet.

[0048] Furthermore, valves are installed on both the refrigerant pipe 41 and the heat transfer pipe 42.

[0049] The black water flowing out of the vacuum flash tank 1 is at about 70°C. Part of the black water enters the first settling tank 21 for settling, and then enters the first ash water tank 22 to clarify the ash water. The ash water in the first ash water tank 22 is then fed into the slag flushing system 23 for slag flushing. Another part of the black water enters the heat exchanger 32 through the black water inlet for cooling. During the cooling process, scale condenses inside the heat exchanger 32, which is then flushed away by the subsequent black water to slow down the scaling cycle inside the heat exchanger 32 and avoid the financial and material losses caused by frequent scaling and blockage of the heat exchanger 32. When the black water drops to below 40°C, it enters the second settling tank 34 for settling and then enters the second ash water tank 35 to clarify the ash water. The ash water in the second ash water tank 35 is then fed into the downstream biochemical treatment system 36 for further treatment.

[0050] For any parts not mentioned in this utility model, existing technologies can be used or referenced.

[0051] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0052] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A coal chemical effluent water long-period operation cooling system, characterized in that, The vacuum flash tank, the reuse branch and the discharge branch are included. The reuse branch includes a first settling tank, a first grey water tank and a slag flushing system; the vacuum flash tank is connected with the first settling tank, the first grey water tank and the slag flushing system in sequence through a reuse pipeline; The discharge branch includes a heat exchanger, a second settling tank, a second grey water tank and a biochemical treatment system; the heat exchanger is connected with a circulating water system; the vacuum flash tank is connected with the heat exchanger, the second settling tank, the second grey water tank and the biochemical treatment system in sequence through a discharge pipeline.

2. The coal chemical effluent water long-period operation cooling system according to claim 1, characterized in that, The heat exchanger includes a black water inlet and a black water outlet; a first discharge pipeline section is connected between the vacuum flash tank and the black water inlet; a second discharge pipeline section is connected between the black water outlet and the second settling tank.

3. The coal chemical industry effluent water long-period operation cooling system according to claim 2, characterized in that, The first discharge pipeline section is provided with a water pump, an inlet valve and a first flow meter; the second discharge pipeline section is provided with an outlet valve and a second flow meter.

4. The coal chemical industry effluent water long-period operation cooling system according to claim 3, characterized in that, The water pump has at least two gears, A and B; the rotation speed of the gear A is greater than that of the gear B; the inlet valve has at least two gears, C and D; the pipe diameter of the gear C is smaller than that of the gear D; the water pump and the inlet valve are matched to form at least two different flow rates of the black water entering the heat exchanger.

5. The coal chemical industry effluent water long-period operation cooling system according to claim 4, characterized in that, A controller is further included; the controller is connected with the water pump, the inlet valve, the first flow meter and the second flow meter; the first flow meter displays a value E; the second flow meter displays a value F; a threshold G is set for the second flow meter; when the value F is less than the threshold G, the controller controls the water pump and the inlet valve to adjust the gears to increase the value E.

6. The coal chemical effluent water long-period operation cooling system according to claim 3, characterized in that, The inlet valve is a vortex valve.

7. The coal chemical industry effluent water long-period operation cooling system according to claim 2, characterized in that, The first discharge pipeline section and the second discharge pipeline section are both provided with thermometers.

8. The coal chemical industry effluent water long-period operation cooling system according to claim 3, characterized in that, The first discharge pipeline section and the inlet valve are detachably connected.

9. The coal chemical effluent water long-period operation cooling system according to claim 1, characterized in that, The circulating water system includes a cold medium pipeline and a hot medium pipeline; the heat exchanger further includes a cold medium inlet and a hot medium outlet; the cold medium pipeline is connected with the cold medium inlet; the hot medium pipeline is connected with the hot medium outlet.

10. The coal chemical industry effluent water long-period operation cooling system according to claim 9, characterized in that, Valves are arranged on the cold medium pipeline and the hot medium pipeline.

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