Municipal sludge fire coal coupling power generation system and control method

Abstract

The invention discloses a municipal sludge fire coal coupling power generation system and a control method, and belongs to the field of sludge treatment, and the municipal sludge fire coal coupling power generation system mainly comprises a sludge moisture content sensor, a sludge storage bin, a sludge level indicator, a central controller, a fire coal storage bin, a fire coal level indicator, a screw feeder, a reciprocating piston pump, a pipeline pressure sensor, a pumping pipeline, a heating air blower and a temperature sensor, a medium-speed coal mill, a peat mixed powder level indicator and a pulverized coal furnace are arranged; in a coupling power generation process that municipal sludge and raw coal are mixed and crushed in proportion, a central controller is internally provided with calculation and control programs, an intelligent matching control method capable of adapting to different sludge water contents and heat values is provided, and the purpose that the sludge treatment capacity is adjusted according to the water contents and the heat values of the sludge and the sludge treatment capacity requirement set by a user is achieved. Different peat proportions and preheating temperatures are obtained through automatic calculation, the conveying amount of municipal sludge and raw coal and the preheating temperatures are controlled, and it is guaranteed that the peat mixture meets the incineration requirement of a power plant.

Description

Technical Field

[0001] The invention patent belongs to the field of sludge treatment, and specifically relates to a municipal sludge coal-fired coupled power generation system and control method. Background Art

[0002] Municipal sludge is the concentrated sediment produced by urban sewage treatment plants during the water treatment process and is a waste associated with sewage treatment. Municipal sludge is a flocculent composed of various microorganisms and organic and inorganic particles. It contains a large amount of water, toxic and harmful substances (such as parasite eggs, bacteria, etc.), plant nutrients (nitrogen, phosphorus, potassium, etc.), organic matter (fats, carbohydrates, proteins, etc.), etc. It is easy to rot and stink. If it is not handled thoroughly, it is easy to cause secondary pollution to the environment.

[0003] The main characteristic of municipal sludge is its high water content. After the original sludge is dehydrated by a centrifuge or filter press, the water content is generally between 60% and 80%. The fixed carbon content in the sludge is small, and its basic low calorific value is generally 560-780kcal / kg, and the highest can reach 1000kcal / kg. The dry basis calorific value is generally around 2500-3000kcal / kg. The higher the water content, the lower the calorific value, and it has a certain resource recycling value. The traditional treatment method of municipal sludge is mainly dehydration and drying followed by incineration. Dehydration treatment is required before incineration, and the disposal cost is very high. The coal-fired coupled sludge power generation technical transformation project was included in the scope of national encouraged projects in 2017. Therefore, the unified treatment of municipal sludge and coal and then combustion for power generation can not only supplement power resources, but also protect the environment from secondary pollution. However, in the current municipal sludge coal-fired coupled power generation system, the sludge dosage will greatly affect the combustion effect in the pulverized coal furnace. Currently, it is not possible to automatically adjust the sludge dosage, nor is it possible to allow users to independently select the sludge dosage while ensuring the combustion effect. Summary of the invention

[0004] The present invention provides a municipal sludge coal-fired coupled power generation system and a control method. In a coupled power generation process in which sludge and raw coal are mixed and crushed in proportion, an intelligent proportioning control method that can adapt to different sludge moisture contents and calorific values ​​is provided, so that different peat proportions and preheating temperatures are automatically calculated according to the moisture content and calorific value of the sludge and the sludge processing volume requirements set by the user, and the metering control and preheating control of the raw coal amount are performed to make the peat mixture meet the incineration requirements of the power plant.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A municipal sludge coal-fired coupled power generation system comprises a sludge moisture sensor 1, a sludge storage bin 2, a sludge level meter 3, a central controller 4, a coal storage bin 5, a coal level meter 6, a screw feeder 7, a reciprocating piston pump 8, a pipeline pressure sensor 9, a pumping pipeline 10, a heating blower 11, a temperature sensor 12, a medium-speed coal mill 13, a peat mixed powder level meter 14, and a pulverized coal furnace 15. A screw feeder 7 is installed below the sludge storage bin 2, a reciprocating piston pump 8 is installed below the screw feeder 7, the front of the reciprocating piston pump is connected to a pumping pipeline 10, the other end of the pumping pipeline 10 is connected to a medium-speed mill 13, the coal storage bin 5 is connected to the medium-speed mill 13 through a belt conveyor, the heating blower 11 is connected to the speed mill 13 through a pipeline, and the medium-speed mill 13 is connected to the pulverized coal machine 15 through a pipeline. The sludge moisture content sensor 1 is fixedly installed at the bottom of the sludge storage bin 2, the sludge level meter 3 is fixedly installed in the sludge storage bin 2, the coal level meter 6 is fixedly installed in the coal storage bin 5, the pipeline pressure sensor 9 is fixedly installed at the inlet end of the pumping pipeline 10, the temperature sensor 12 is fixedly installed at the bottom of the medium-speed mill, the peat mixed powder level meter 14 is fixedly installed in the coal mill, and the central controller 4 is connected to the sludge moisture content sensor 1, the sludge level meter 3, the screw feeder 7, the reciprocating piston pump 8, the pipeline pressure sensor 9, the heating blower 11, the pulverized coal furnace 15, the temperature sensor 12 in the medium-speed coal mill 13 and the peat mixed powder level meter 14, and the temperature sensor 12 in the coal storage bin 5 through cables.

[0007] The sludge storage bin 2 stores urban sludge, and the coal storage bin 5 stores coal lumps. The screw feeder 7 transports the urban sludge in the sludge storage bin 2 to the reciprocating piston pump 8, and the reciprocating piston pump 8 transports the urban sludge therein to the medium-speed coal mill 13 through the pumping pipeline 10. The medium-speed coal mill 13 grinds the peat mixture into powder and transports it to the pulverized coal furnace for combustion. The heating blower 11 generates heated air and transports it to the medium-speed coal mill 13 to heat the peat mixture in the medium-speed coal mill 13.

[0008] In the municipal sludge coal-fired coupled power generation control method, the weight proportion of the added sludge ranges from 4wt% to 15wt%, and different sludge addition amounts are automatically selected according to different sludge calorific values, moisture contents and user sludge treatment requirements.

[0009] The central controller 4 has a built-in calculation and control program, which can automatically calculate the coal delivery amount according to the user's heating demand and control the municipal sludge coal-fired coupled power generation system.

[0010] Furthermore, the calculation and control program built into the central controller 4 is shown in the flowchart as follows: Figure 2As shown, it mainly includes the following steps:

[0011] S1. When the system restarts and starts running, Figure 2 As shown, the central controller 4 will be initialized, the cycle number flag is set to 0, and the calorific values ​​of sludge and coal are initialized to 600 kcal / kg and 7000 kcal / kg respectively.

[0012] S2. The system requires the user to select the municipal sludge treatment volume requirement. The user can choose from five levels: "maximum sludge blending", "high sludge blending", "medium sludge blending", "low sludge blending" and "no sludge blending".

[0013] S3. The moisture content x (in wt%) of the municipal sludge is detected by the moisture sensor 1 in the sludge storage bin 2, and the sludge mixing amount z and the actual preheating temperature u1 of the peat mixture are calculated according to the sludge processing volume requirement input by the user in S2. The calculation formula is:

[0014] When the "maximum sludge dosage"

[0015]

[0016] When "high sludge content"

[0017]

[0018] When the "medium sludge dosage"

[0019]

[0020] u1=u0

[0021] When "low sludge dosage"

[0022]

[0023] When “no sludge”

[0024] z=0

[0025]

[0026] Where y1 is the calorific value of coal, in kcal / kg; y2 is the lower calorific value of sludge base, in kcal / kg; a is the specific heat capacity of peat mixture, in kJ / (kg×℃), and the default value is 1kJ / (kg×℃); the default preheating temperature of peat mixture is u0, in ℃, and the default value is 50℃.

[0027] According to the calorific value set by the user and the combustion efficiency μ in the pulverized coal furnace (the default value is 90%), the delivery rate c (in kg / s) of the peat mixture is calculated as follows:

[0028]

[0029] g is the heating demand set by the user, in kcal / s.

[0030] S4. According to the sludge delivery amount z and the actual preheating temperature u1 of the peat mixture calculated in S3, the speed of the screw feeder, the delivery speed of the piston pump, and the temperature and air volume of the blower are controlled.

[0031] When the density of municipal sludge is 1100kg / m3, the pumping speed v1 of the piston pump is:

[0032]

[0033] The unit of v1 is m / s, and r is the inner radius of the piston cylinder in the piston pump, in m.

[0034] The speed v2 of the screw feeder is:

[0035]

[0036] The unit of v2 is RPM, R is the inner radius of the screw feeder, the unit is m, and d is the pitch, the unit is m.

[0037] When the temperature of the peat mixture ground in the medium-speed coal mill 13 is lower than the actual preheating temperature u1 of the peat mixture calculated in S3, the temperature and air volume of the air outlet of the blower are slowly increased. When the temperature of the peat mixture ground in the medium-speed coal mill 13 is lower than the actual preheating temperature u1 of the peat mixture calculated in S3, the temperature and air volume of the air outlet of the blower are slowly reduced.

[0038] S5. After S4 is executed, the central controller 4 will detect the material levels of sludge, coal and peat mixed powder respectively according to the sludge material level meter 3, coal material level meter 6 and peat mixed powder material level meter 14. When the material levels of the three materials are abnormal, the central controller 4 will prompt and alarm. When the coal material level is 0, it will automatically stop. The central controller 4 will also detect the pumping pressure in the pipeline in real time according to the pipeline pressure sensor 9. When the pressure exceeds 20MPa, an alarm will be issued and the pumping of urban sludge will be stopped.

[0039] S6. When all tests in S5 are normal for 2 hours, the central controller 4 starts to calculate the unit mass calorific value d1 of the peat mixture in the pulverized coal furnace in the past hour, in kcal / kg, and calculates the number of cycles flag=flag+1, the result is 1, and stores it.

[0040] S7, determine whether there are two average calorific value of sludge ratios, that is, whether flag is 2. In this case, it will be determined as "no", the previously calculated sludge dosage will be reduced by 50%, and the moisture content x of the sludge will be detected by the moisture content detector in the sludge storage bin.

[0041] S8. Return to execute S3, recalculate the sludge delivery volume z and the actual preheating temperature u1 of the peat mixture, and execute S4, S5, and S6 in sequence.

[0042] S9. Determine again whether there are two average calorific values ​​of sludge ratios, that is, whether the flag is 2. In this case, it will be determined as "yes", and the unit mass calorific value (d1 and d2 respectively) of the peat mixture in the pulverized coal furnace under two sludge dosages (z1 and 0.5z1 respectively) is obtained. At this time, the central controller 4 further calculates the correct calorific value y1 of the coal and the calorific value y2 of the sludge, and the calculation formula is as follows:

[0043]

[0044] Replace the default values ​​of the correct coal calorific value y1 and sludge calorific value y2, and set the number of cycles flag to 1.

[0045] S10, according to the correct calorific value y1 of coal and calorific value y2 of sludge in S9, return to S3 again, calculate the corrected coal to sludge ratio, then detect the sludge moisture content, recalculate the preheating temperature of the peat-coal mixture, and finally start the loop execution program.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1) Based on the traditional municipal sludge coal-fired coupled power generation system, the present invention adds a variety of detection devices, which can automatically calculate the calorific value of coal and sludge, so as to automatically calculate the preheating temperature of the peat mixture, and use a heated blower for heating, saving a lot of manpower and material resources, and achieving the effect of automatic control.

[0048] 2) The control system provided by the present invention allows the user to set the current sludge processing volume and the current calorific value of the pulverized coal furnace respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a structural diagram of the municipal sludge coal-fired coupled power generation system of the present invention.

[0050] In the figure: 1-sludge moisture content sensor, 2-sludge storage bin, 3-sludge level meter, 4-central controller, 5-coal storage bin, 6-coal level meter, 7-screw feeder, 8-reciprocating piston pump, 9-pipeline pressure sensor, 10-pumping pipeline, 11-heating blower, 12-temperature sensor, 13-medium speed coal mill, 14-peat mixed powder level meter, 15-pulverized coal furnace.

[0051] Figure 2 It is a flow chart of the ratio control program of coal and sludge in the municipal sludge coal-fired coupled power generation system of the present invention. DETAILED DESCRIPTION

[0052] The present invention is further described in detail below with reference to the accompanying drawings.

[0053] Embodiment 1:

[0054] See also Figure 1 ,This embodiment provides a municipal sludge coal-fired coupled power generation system and control method, including the following steps:

[0055] like Figure 1 The municipal sludge coal-fired coupled power generation system shown includes a sludge moisture content sensor 1, a sludge storage bin 2, a sludge level meter 3, a central controller 4, a coal storage bin 5, a coal level meter 6, a screw feeder 7, a reciprocating piston pump 8, a pipeline pressure sensor 9, a pumping pipeline 10, a heating blower 11, a temperature sensor 12, a medium-speed coal mill 13, a peat mixed powder level meter 14, and a pulverized coal furnace 15.

[0056] A screw feeder 7 is installed below the sludge storage bin 2, and a reciprocating piston pump 8 is installed below the screw feeder 7. The front of the reciprocating piston pump is connected to a pumping pipe 10, and the other end of the pumping pipe 10 is connected to a medium-speed mill 13. The coal storage bin 5 is connected to the medium-speed mill 13 through a belt conveyor, and the heating blower 11 is connected to the speed mill 13 through a pipeline, and the medium-speed mill 13 is connected to a pulverized coal machine 15 through a pipeline. The sludge moisture content sensor 1 is fixedly installed at the bottom of the sludge storage bin 2, the sludge level meter 3 is fixedly installed in the sludge storage bin 2, the coal level meter 6 is fixedly installed in the coal storage bin 5, the pipeline pressure sensor 9 is fixedly installed at the inlet end of the pumping pipeline 10, the temperature sensor 12 is fixedly installed at the bottom of the medium-speed mill, and the peat mixed powder level meter 14 is fixedly installed in the coal mill; the central controller 4 is connected to the sludge moisture content sensor 1, the sludge level meter 3, the screw feeder 7, the reciprocating piston pump 8, the pipeline pressure sensor 9, the heating blower 11, the medium-speed coal mill 13 and the temperature sensor 12 and the peat mixed powder level meter 14 therein, the coal storage bin 5 and the temperature sensor therein, and the pulverized coal furnace 15 through cables.

[0057] See also Figure 1 and Figure 2 This embodiment provides a municipal sludge coal-fired coupled power generation system and control method, comprising the following steps:

[0058] S1. When the system restarts and starts running, Figure 2 As shown, the central controller 4 will be initialized, the cycle number flag is set to 0, and the calorific values ​​of sludge and coal are initialized to 600 kcal / kg and 7000 kcal / kg respectively.

[0059] S2. The system requires the user to select the urban sludge treatment volume requirement, and the user selects the “maximum sludge blending amount”.

[0060] S3, using the moisture sensor 1 in the sludge storage bin 2 to detect the moisture content x of the municipal sludge, the detection result is 60wt%. At this time, according to the sludge processing volume requirement input by the user in S2 as "maximum sludge mixing amount", the calculation formulas for the sludge mixing amount z and the actual preheating temperature u1 of the peat mixture are calculated as follows:

[0061]

[0062] Where y1 is the calorific value of coal, in kcal / kg; y2 is the lower calorific value of sludge base, in kcal / kg; a is the specific heat capacity of peat mixture, in kJ / (kg×℃), and the default value is 1kJ / (kg×℃); the default preheating temperature of peat mixture is u0, in ℃, and the default value is 50℃.

[0063] It can be calculated that the sludge dosage z=0.09 and the preheating temperature u1=62.05℃

[0064] According to the calorific value set by the user and the combustion efficiency μ in the pulverized coal furnace (the default value is 90%), the delivery rate c (in kg / s) of the peat mixture is calculated as follows:

[0065]

[0066] g is the heat demand set by the user, in kcal / s. The user sets it to 1.3×105kcal / s. It can be calculated that the delivery rate c of the peat mixture is 22.5kg / s.

[0067] S4. According to the sludge delivery amount z and the actual preheating temperature u1 of the peat mixture calculated in S3, the speed of the screw feeder, the delivery speed of the piston pump, and the temperature and air volume of the blower are controlled.

[0068] The density of urban sludge is 1100kg / m3, and the inner radius r of the piston cylinder in the user's piston pump is 0.15m. The pumping speed v1 of the piston pump is:

[0069]

[0070] The unit of v1 is m / s, and it can be calculated that v1=0.03m / s.

[0071] The inner diameter of the user's screw feeder is R = 0.2m, and the pitch is d = 0.15m. The calculation formula for the speed v2 of the screw feeder is:

[0072]

[0073] It can be calculated that the speed of the screw feeder is v2 = 11.8 RPM.

[0074] When the temperature of the peat mixture ground in the medium-speed coal mill 13 is lower than the actual preheating temperature u1 of the peat mixture calculated in S3, the temperature and air volume of the air outlet of the blower are slowly increased. When the temperature of the peat mixture ground in the medium-speed coal mill 13 is lower than the actual preheating temperature u1 of the peat mixture calculated in S3, the temperature and air volume of the air outlet of the blower are slowly reduced.

[0075] S5. After S4 is executed, the central controller 4 will detect the material levels of sludge, coal and peat mixed powder respectively according to the sludge material level meter 3, coal material level meter 6 and peat mixed powder material level meter 14. When the material levels of the three materials are abnormal, the central controller 4 will prompt and alarm. When the coal material level is 0, it will automatically stop. The central controller 4 will also detect the pumping pressure in the pipeline in real time according to the pipeline pressure sensor 9. When the pressure exceeds 20MPa, an alarm will be issued and the pumping of urban sludge will be stopped.

[0076] S6. After all tests in S5 are normal for 2 hours, the central controller 4 starts to calculate the average calorific value of the peat mixture in the pulverized coal furnace in the past hour, which is 1.2658×105kcal / s. The calorific value of the peat mixture can be calculated to be 5.63×103kcal / kg. The calculation cycle number flag=flag+1, the result is 1 at this time, and it is stored.

[0077] S7, determine whether there are two average calorific value of sludge ratios, that is, whether flag is 2. In this case, it will be judged as "no", and the previously calculated sludge dosage will be reduced by 50%, that is, 0.045wt%, and the moisture content x of the sludge will be detected by the moisture content detector in the sludge storage bin, and the detection result is still 60wt%.

[0078] S8. Return to execute S3, recalculate the sludge delivery volume z and the actual preheating temperature u1 of the peat mixture, and execute S4, S5, and S6 in sequence. Finally, the calorific value of the peat mixture with a dosage of 0.045wt% of municipal sludge is obtained to be 5.87×103kcal / kg.

[0079] S9. Determine again whether there are two average calorific values ​​of sludge ratios, that is, whether flag is 2. In this case, it will be determined as "yes", and the unit mass calorific value of the peat mixture in the pulverized coal furnace under two sludge dosages (0.09wt% and 0.045wt%) is obtained (5.63×103kcal / kg and 5.87×103kcal / kg, respectively). At this time, the central controller 4 further calculates the correct calorific value y1 of the coal and the calorific value y2 of the sludge, and the calculation formula is as follows:

[0080]

[0081] The correct calorific value of coal y1 is calculated to be 6800 kcal / kg, and the calorific value of sludge y2 is 700 kcal / kg. Replace their respective default values ​​and set the number of cycles flag to 1.

[0082] S10, according to the correct calorific value y1 of coal and calorific value y2 of sludge in S9, return to S3 again, calculate the corrected coal to sludge ratio, then detect the sludge moisture content, recalculate the preheating temperature of the peat-coal mixture, and finally start the loop execution program.

Claims

1. A municipal sludge coal-fired coupled power generation system, characterized in that: It includes a sludge moisture content sensor 1, a sludge storage bin 2, a sludge level meter 3, a central controller 4, a coal storage bin 5, a coal level meter 6, a screw feeder 7, a reciprocating piston pump 8, a pipeline pressure sensor 9, a pumping pipeline 10, a heating blower 11, a temperature sensor 12, a medium-speed coal mill 13, a peat mixed powder level meter 14, and a pulverized coal furnace 15. The screw feeder 7 is installed below the sludge storage bin 2, and the reciprocating piston pump 8 is installed below the screw feeder 7. The front of the reciprocating piston pump is connected to the pumping pipeline 10, and the other end of the pumping pipeline 10 is connected to the medium-speed mill 13. The coal storage bin 5 is connected to the medium-speed mill 13 through a belt conveyor, the heating blower 11 is connected to the speed mill 13 through a pipeline, and the medium-speed mill 13 is connected to the pulverized coal machine 15 through a pipeline. The sludge moisture content sensor 1 is fixedly installed at the bottom of the sludge storage bin 2, the sludge level meter 3 is fixedly installed in the sludge storage bin 2, the coal level meter 6 is fixedly installed in the coal storage bin 5, the pipeline pressure sensor 9 is fixedly installed at the inlet end of the pumping pipeline 10, the temperature sensor 12 is fixedly installed at the bottom of the medium-speed mill, the peat mixed powder level meter 14 is fixedly installed in the coal mill, and the central controller 4 is connected to the sludge moisture content sensor 1, the sludge level meter 3, the screw feeder 7, the reciprocating piston pump 8, the pipeline pressure sensor 9, the heating blower 11, the pulverized coal furnace 15, the temperature sensor 12 in the medium-speed coal mill 13 and the peat mixed powder level meter 14, and the temperature sensor 12 in the coal storage bin 5 through cables.

2. According to claim 1, a control method for municipal sludge coal-fired coupled power generation, characterized in that: The central controller 4 has a built-in calculation and control program, which can automatically select different sludge blending amounts according to different sludge calorific values, moisture contents and user sludge treatment requirements, and can control the municipal sludge coal-fired coupled power generation system.

3. The control method of a municipal sludge coal-fired coupled power generation system according to claim 2, characterized in that: The flow chart of the calculation and control program built into the central controller 4 is shown in FIG2 , which mainly includes the following steps: S1. When the system restarts and starts running, as shown in FIG. 2 , the central controller 4 will be initialized, and the cycle number flag is set to 0, and the calorific values ​​of the sludge and coal are initialized to 600 kcal / kg and 7000 kcal / kg respectively. S2. The system requires the user to select the municipal sludge treatment volume requirement. The user can choose from five levels: "highest sludge blending", "high sludge blending", "medium sludge blending", "low sludge blending" and "no sludge blending". S3. The moisture content x (in wt%) of the municipal sludge is detected by the moisture sensor 1 in the sludge storage bin 2, and the sludge mixing amount z and the actual preheating temperature u1 of the peat powder are calculated according to the sludge processing volume requirement input by the user in S2. The calculation formula is: When the "maximum sludge dosage" When "high sludge dosage" When the "medium sludge dosage" u1=u0 When "low sludge dosage" When "no sludge" z＝0 Where y1 is the calorific value of coal, in kcal / kg; y2 is the lower calorific value of sludge base, in kcal / kg; a is the specific heat capacity of peat mixture, in kJ / (kg×℃), and the default value is 1kJ / (kg×℃); the default preheating temperature of peat mixture is u0, in ℃, and the default value is 50℃. According to the calorific value set by the user and the combustion efficiency μ in the pulverized coal furnace (the default value is 90%), the peat powder delivery rate c (in kg / s) is calculated as follows: g is the heating demand set by the user, in kcal / s. S4. According to the sludge delivery amount z and the actual preheating temperature u1 of the peat powder calculated by S3, the speed of the screw feeder, the delivery speed of the piston pump, and the temperature and air volume of the blower are controlled. When the density of municipal sludge is 1100kg / m3, the pumping speed v1 of the piston pump is: The unit of v1 is m / s, and r is the inner radius of the piston cylinder in the piston pump, in m. The speed v2 of the screw feeder is: The unit of v2 is RPM, R is the inner radius of the screw feeder, the unit is m, and d is the pitch, the unit is m. When the temperature of the peat powder ground in the medium-speed coal mill 13 is lower than the actual preheating temperature u1 of the peat powder calculated in S3, the temperature and air volume of the air outlet of the blower are slowly increased. When the temperature of the peat powder ground in the medium-speed coal mill 13 is lower than the actual preheating temperature u1 of the peat powder calculated in S3, the temperature and air volume of the air outlet of the blower are slowly reduced. S5. After S4 is executed, the central controller 4 will detect the material levels of sludge, coal and peat mixed powder respectively according to the sludge material level meter 3, coal material level meter 6 and peat mixed powder material level meter 14. When the material levels of the three materials are abnormal, the central controller 4 will prompt and alarm. When the coal material level is 0, it will automatically stop. The central controller 4 will also detect the pumping pressure in the pipeline in real time according to the pipeline pressure sensor 9. When the pressure exceeds 20MPa, an alarm will be issued and the pumping of urban sludge will be stopped. S6. When all tests in S5 are normal for 2 hours, the central controller 4 starts to calculate the unit mass calorific value d1 of the peat mixture in the pulverized coal furnace in the past hour, in kcal / kg, and calculates the number of cycles flag=flag+1, the result is 1, and stores it. S7, determine whether there are two average calorific value of sludge ratios, that is, whether flag is 2. In this case, it will be determined as "no", the previously calculated sludge dosage will be reduced by 50%, and the moisture content x of the sludge will be detected by the moisture content detector in the sludge storage bin. S8. Return to execute S3, recalculate the sludge delivery volume z and the actual preheating temperature u1 of the peat powder, and execute S4, S5, and S6 in sequence. S9, again determine whether there are two average calorific values ​​of sludge ratios, that is, whether the flag is 2. In this case, it will be determined as "yes", and the unit mass calorific value (d1 and d2 respectively) of the peat mixture in the pulverized coal furnace under two sludge dosages (z1 and 0.5z1 respectively) is obtained. At this time, the central controller 4 further calculates the correct calorific value y1 of the coal and the calorific value y2 of the sludge, and the calculation formula is as follows: Replace the default values ​​of the correct coal calorific value y1 and sludge calorific value y2, and set the number of cycles flag to 1. S10, according to the correct calorific value y1 of coal and calorific value y2 of sludge in S9, return to S3 again, calculate the corrected coal to sludge ratio, then detect the sludge moisture content, recalculate the preheating temperature of the peat powder mixture, and finally start the loop execution program.

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