Non-afterburning type natural gas distributed energy waste heat utilization control system

Abstract

The utility model relates to the technical field of waste heat utilization in the ceramic industry, and discloses a non-afterburning type natural gas distributed energy waste heat utilization control system which comprises a main flue, a natural gas generator set, a hot blast stove, a spray tower, a main control device, a data acquisition assembly and a control assembly. The hot-blast stove is communicated with the spray tower, and a connection port is formed in a communication path; the flue gas exhaust end of the natural gas generator set is connected to the connection port through the main flue; a bypass chimney is arranged on the main flue close to the natural gas generator set; a branch pipeline communicated with the atmosphere is arranged on the main flue close to the connection port; the control assembly is connected with the main flue, the bypass chimney and the branch pipeline; the data acquisition assembly is mounted at the flue gas exhaust end and the connection port of the natural gas generator set and in the spray tower; the main control device is in communication connection with all units; a non-afterburning mode is adopted, smoke waste heat of a natural gas generator set is mixed with hot air of a hot air furnace to be supplied to a spray tower, existing resources of enterprises are utilized to the maximum extent, and an economical and feasible energy-saving and carbon-reducing transformation mode is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat utilization in the ceramic industry, and in particular to a non-supplementary combustion type natural gas distributed energy waste heat utilization control system. Background Art

[0002] Spray towers and hot air furnaces play a vital role in ceramic production. Spray towers are key equipment used to spray and dry slurry into powder in ceramic production. The slurry is fed into the nozzle at the top of the spray tower through a high-pressure pump. The nozzle atomizes the slurry into extremely fine droplets. The droplets come into contact with the high-temperature hot air from the hot air furnace, and the water evaporates rapidly, leaving dry powder. The high-temperature hot air provided by the hot air furnace is an indispensable heat source in the spray drying process. A stable and high-quality hot air supply can ensure the continuity of the drying process and the uniformity of the product. The fuel for the dry powder process in the traditional ceramic industry is provided by external natural gas, diesel, coal or homemade water gas. The fuel is burned in the hot air furnace to form hot air. Although the hot air furnace can provide a stable heat source in this way, the energy utilization rate is low and the energy cost of the enterprise is high.

[0003] Distributed energy technology is currently used to achieve cascaded energy utilization on the user side. For example, foreign countries have adopted the "distributed energy + supplementary combustion" method to achieve green production in the ceramic industry. That is, natural gas generators are used to generate electricity, and high-temperature flue gas is mixed with sufficient air and supplemented by the flue afterburner to the required temperature before being sent to the spray tower. This method completely replaces the traditional hot air furnace and can achieve precise control of the tower top temperature.

[0004] However, this method is not suitable for domestic ceramic production enterprises. As a traditional heating equipment, the hot air furnace has a long history in the ceramic industry, and its technology is mature and reliable. In contrast, the hot air furnace system that completely abandons mature technology requires a large technical transformation and high cost. It may be difficult for some domestic small and medium-sized enterprises to bear, and the differences in existing technologies may make it difficult to implement. In addition, the domestic ceramic industry cannot adopt this technical route for transformation due to the requirements of "heat-based electricity" for distributed projects and stable production needs.

[0005] Therefore, how to combine distributed energy and hot air furnaces and adopt the "distributed energy + non-supplementary combustion" method to provide heat energy for the spray tower has become a difficult problem that domestic ceramic manufacturers need to overcome. Utility Model Content

[0006] The utility model aims to provide a non-supplementary natural gas distributed energy waste heat utilization control system, which can achieve economically feasible technical transformation based on the original hot blast furnace-spray tower system while retaining the traditional hot blast furnace, ensure the stability of the system's multi-condition switching, and at the same time provide the spray tower with stable and high-quality hot air to improve energy utilization.

[0007] The basic scheme provided by the utility model is: a non-supplementary combustion type natural gas distributed energy waste heat utilization control system, including a main flue, a natural gas generator set, a hot air furnace, a spray tower, a main control device, a data acquisition component and a control component;

[0008] The hot blast furnace is connected to the spray tower and has a connection port on the connection path; the smoke exhaust end of the natural gas generator set is connected to the connection port through the main flue; a bypass chimney is provided on the main flue near the natural gas generator set; a branch pipeline connected to the atmosphere is provided on the main flue near the connection port; the control component is connected to the main flue, the bypass chimney and the branch pipeline; the data acquisition component is installed at the smoke exhaust end, the connection port and the spray tower of the natural gas generator set;

[0009] The main control device is communicatively connected with the natural gas generator set, hot blast furnace, spray tower, data acquisition component and control component; the control component is controlled by the main control device, and is used to control the opening of the main flue and the closing of the bypass chimney, or to control the closing of the main flue and the opening of the bypass chimney, and is also used to control the opening of the branch pipeline under special circumstances, so that it matches the required working conditions of the natural gas generator set, hot blast furnace and spray tower.

[0010] The working principle and advantages of the utility model are: adopting the non-supplementary combustion form, adding a natural gas generator set on the basis of retaining the original spray tower and hot blast furnace system, and using the tail flue gas of the unit to supply the hot air of the spray tower, making the most of the existing resources of the enterprise, with low difficulty of transformation, low cost and small investment; in conventional ceramic production, the spray tower and the hot blast furnace are located in the factory building, while the natural gas generator set is mostly located outside the factory building, with a certain distance, and if it is transported in multiple branch flues or multiple pipelines, it is easy to cause heat loss. In addition, the structural characteristics of the conventional hot blast furnace itself make it very difficult or even impossible to connect the branch flue to the hot blast furnace for transformation. Therefore, whether it is to reduce the waste heat transmission loss, the feasibility of technical transformation, or considering the accuracy of the spray tower temperature control in the later stage, the stability of switching between different working conditions of the whole system, this scheme retains the original hot blast furnace and spray tower structure, connects the natural gas generator set to the connection port of the hot blast furnace and the spray tower with an independent flue, mixes the flue gas of the natural gas generator set and the hot air of the hot blast furnace at the connection port, and then sends it to the spray tower, which is an effective and economically feasible energy-saving and carbon-reducing transformation method in the existing ceramic production equipment layout.

[0011] Through the bypass chimney and branch pipes installed on the main flue, as well as the combined configuration and position layout of the control components and data acquisition components, stable switching of various working conditions can be achieved with simple control logic to ensure stable production of the enterprise (ceramic enterprises produce in three shifts without stopping the furnace, and have extremely high requirements for system stability).

[0012] The temperature control of the traditional hot blast furnace is to adjust the temperature by increasing or decreasing the number of starting burners inside the hot blast furnace according to the temperature of the spray tower. At the same time, the temperature is adjusted by manually adjusting the opening of the hot blast furnace shell tuyere based on experience. After the opening of the shell tuyere is adjusted, it is generally not moved. Although this type of adjustment can basically meet the needs through experience adjustment, there is only a single one-to-one combination of temperature monitoring and adjustment points. Once a node has a problem, the temperature accuracy cannot be guaranteed. On the basis of ensuring the stable switching of the system operating conditions, this solution adds digital acquisition components at the flue gas exhaust end, the connection port and the spray tower of the natural gas generator set to form multiple monitoring points, which is conducive to temperature adjustment and data mutual verification during operation, and is conducive to ensuring the accuracy of adjustment and the safe operation of the system. Based on this, the setting of the structure of this solution is not only conducive to economic transformation, but also more conducive to the accuracy of the spray tower temperature control and the stability of switching between different operating conditions of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the structure of a non-supplementary combustion type natural gas distributed energy waste heat utilization control system provided by an embodiment of the utility model;

[0014] Figure 2 The operation process of a non-supplementary combustion type natural gas distributed energy waste heat utilization control system provided by the embodiment of the utility model Figure 1 ;

[0015] Figure 3 The operation process of a non-supplementary combustion type natural gas distributed energy waste heat utilization control system provided by the embodiment of the utility model Figure 2 ;

[0016] Figure 4 The operation process of a non-supplementary combustion type natural gas distributed energy waste heat utilization control system provided by the embodiment of the utility model Figure 3 ;

[0017] Figure 5 The operation process of a non-supplementary combustion type natural gas distributed energy waste heat utilization control system provided by the embodiment of the utility model Figure 4 ;

[0018] Figure 6 The operation process of a non-supplementary combustion type natural gas distributed energy waste heat utilization control system provided by the embodiment of the utility model Figure 5 ;

[0019] Figure 7 The operation process of a non-supplementary combustion type natural gas distributed energy waste heat utilization control system provided by the embodiment of the utility model Figure 6 ;

[0020] Figure 8 The operation process of a non-supplementary combustion type natural gas distributed energy waste heat utilization control system provided by the embodiment of the utility model Figure 7 . DETAILED DESCRIPTION

[0021] The following is a further detailed description through specific implementation methods:

[0022] Embodiment 1

[0023] Basically as attached Figure 1 Shown: A non-supplementary combustion type natural gas distributed energy waste heat utilization control system, including a main flue, a natural gas generator set (referred to as the unit), a hot air furnace, a spray tower, a main control device, a data acquisition component and a control component.

[0024] It should be noted that this scheme can be based on the transformation of the hot blast furnaces and spray towers and their corresponding systems that have been built or are to be built in existing ceramic enterprises. On the basis of minimizing the transformation of the original hot blast furnaces and spray towers, economically feasible energy-saving and carbon-reduction transformation can be carried out, which is suitable for application in most ceramic enterprises. The main control device represents the entire control system, which is transformed accordingly on the basis of meeting the mature operating modes of conventional hot blast furnaces and spray towers, so as to realize the utilization of the waste heat of the natural gas engine group in the original system of the hot blast furnace and spray tower of the ceramic enterprise by the corresponding control strategy of this scheme, and ensure the stable operation of the hot blast furnace and spray tower. This scheme emphasizes and protects the connection structure, and does not limit the specific internal connection method of the main control device. It can be reasonably set and transformed based on the effect to be achieved by this device.

[0025] The hot blast furnace is connected to the spray tower and has a connection port on the connection path; the smoke exhaust end of the natural gas generator set is connected to the connection port through the main flue, so that the smoke of the natural gas generator set can be input into the spray tower through the connection port; a bypass chimney is provided on the main flue near the natural gas generator set; a branch pipeline connected to the atmosphere is provided on the main flue near the connection port, and the bypass chimney should be as close to the natural gas generator set as possible to ensure normal starting of the generator set.

[0026] Specifically, the length of the main flue should be controlled within 200m, and the diameter is determined according to the diameter of the exhaust port of the generator set. In this embodiment, the main flue is about 160m long, with an outer diameter of 1760mm and an inner diameter of 1200mm. The insulation materials are insulation cotton + high-aluminum polylight ball bricks from outside to inside to ensure that the waste heat of the natural gas generator set can be input into the spray tower with the smallest possible loss, thereby improving the utilization rate of thermal energy. At the same time, the diameter is set reasonably to meet the maximum allowable back pressure of the generator set while ensuring that the negative pressure point in the main flue is as far away from the generator set as possible to ensure safe access. It can be said that directly accessing the connection port with an independent flue is currently a very effective and feasible technical transformation method based on the original system.

[0027] Gas turbines can be used for natural gas generator sets. They have a slightly lower power generation efficiency, but have a high exhaust temperature, a large exhaust volume, and a large amount of waste heat, making them more suitable for energy cascade utilization scenarios with heating as the main purpose. Units with flue gas temperatures above 500°C account for 68.5%, and units with flue gas temperatures above 450°C account for 93.8%. The exhaust gas is close to the demand of the spray tower (usually required to be between 550 and 650°C), and the waste heat is fully utilized. In addition, gas turbines do not require frequent maintenance, and the lubricating oil only needs to be replaced once a year, which can fully meet the production arrangement needs of the enterprise and is more in line with the production needs of the spray tower that requires long-term continuous and stable operation.

[0028] The control component is connected to the main flue, the bypass chimney and the branch pipeline; the data acquisition component is installed at the flue gas discharge end, the connection port and the spray tower of the natural gas generator set.

[0029] Specifically, the control component includes a first valve D1 arranged on the bypass chimney, which is used to control the opening and closing of the bypass chimney. In this embodiment, the bypass chimney is 1.75m away from the exhaust port of the generator set, and the first valve is 2.5m away from the branch tee between the main flue and the bypass chimney. This setting can enable the generator set to start in a shorter time.

[0030] The control component also includes a second valve D2 and a third valve D3, which are arranged on the main flue and located between the bypass chimney and the branch pipeline, and are used for the opening and closing control of the main flue (i.e., the opening and closing control connected to the rear-end spray tower). Because it is difficult for a large-caliber, high-temperature flue gas valve to achieve zero leakage after running for a period of time, after air leaks into the flue gas system, when the spray tower is running independently, it is easy to interfere with the temperature control in the tower. D2 and D3 are used to form a double insurance to ensure that no air leaks into the main flue when the spray tower or the unit is running separately and independently, further interfering with or affecting the spray tower system. D2 and D3 are the core components for realizing the overall stable linkage of the system and ensuring the precise temperature control of the original system of the enterprise after the construction of this system.

[0031] The second valve D2 and the third valve D3 have a first distance, and the first distance should ensure that when the second valve and the third valve are fully opened, the distance between their valve plates is not less than 300mm to ensure the normal opening and closing of the second valve and the third valve. The distance between the second valve D2 and the bypass chimney should be controlled at 2 to 3m to reduce the impact of the main flue system on it when the generator set is running independently. An expansion joint should be installed on the main flue between D2 and the bypass chimney to prevent the back-end system from exerting force on the bypass chimney due to thermal expansion and contraction.

[0032] The control assembly further comprises a fourth valve Q1 arranged on the branch pipeline, which controls the opening and closing of the branch pipeline to prevent air from leaking into the main flue and interfering with the temperature control in the spray tower.

[0033] The first valve D1 and the second valve D2 are fully open and fully closed electric high-temperature flue gas butterfly valves, the third valve D3 is a fully open and fully closed electric high-temperature flue gas butterfly valve or a graded adjustable opening electric high-temperature flue gas butterfly valve, and the fourth valve Q1 is a fully open and fully closed pneumatic high-temperature flue gas butterfly valve. The fully open and fully closed type means that it is 100% open after opening and 100% closed after closing. The graded adjustable opening type means that a preset opening is first determined, and when the system is running, it is opened to the preset opening at a rate of about 5 to 10 minutes to reach 100% opening. Among them, when the third valve is a graded adjustable opening valve, the third valve is opened slowly at a preset rate, and can be stopped at the current opening at any time through control, which can ensure that the fluctuations in the process are effectively responded to when the system operating conditions are switched, and the fault can be removed in time when a fault occurs. After the third valve is replaced with a valve with graded opening adjustment, from the perspective of the entire system, an adjustable point is added. When the flue diameter or material setting is not reasonable and the flue resistance is insufficient, the valve can be set to be adjustable to increase the resistance to ensure that the generator set will not have negative pressure, so as to adjust the main flue resistance to adapt to the stability of the overall system operation.

[0034] The maximum threshold value of the operating temperature of the first valve, the second valve, the third valve and the fourth valve is not less than 700°C, and the leakage rate is less than 1.5%, so as to ensure that the valves can operate normally and stably at the exhaust temperature corresponding to different loads of the generator set (including the exhaust temperature when the unit is started).

[0035] Specifically, the data acquisition component includes a first temperature acquisition component (i.e., a first temperature sensor T1) and a high-temperature flue gas flow acquisition component (i.e., a high-temperature flue gas flowmeter F1) arranged at the exhaust port of the natural gas generator set, a second temperature acquisition component (i.e., a second temperature sensor T2) arranged at the connection port, and a tower top temperature acquisition component (i.e., a tower top temperature sensor T3) arranged in the spray tower.

[0036] The data acquisition component also includes a first pressure acquisition component (i.e., a first pressure sensor P1) arranged at the exhaust port of the natural gas generator set, and a second pressure acquisition component (i.e., a second pressure sensor P2) arranged at the connection port; the first pressure acquisition component P1 and the fourth valve Q1 are interlocked and controlled by the main control device.

[0037] Since the flue diameter is relatively large, for accurate measurement, it is recommended that each sensor be arranged in 2 to 3 groups evenly on the flue diameter.

[0038] The main control device is connected to the natural gas generator set, hot air furnace, spray tower, data acquisition component and control component. During the specific operation process, the data of the data acquisition component is transmitted to the main control device, that is, the flue gas pressure, flue gas temperature and flue gas flow at the exhaust port of the unit are monitored respectively through P1, T1 and F1; the flue gas pressure and flue gas temperature at the main flue connection port are monitored respectively through P2 and T2; and T3 is used to feedback whether the temperature in the spray tower meets the required working conditions.

[0039] The hot air furnace mainly uses T2, T3 and F1, or T3 alone to feedback and adjust the hot air furnace load, and then adjust the hot air temperature; P1 and P2 are mainly used for pressure monitoring, especially negative pressure monitoring, to ensure the safe connection between the natural gas generator set and the spray tower. The main logical relationship of the system is as follows:

[0040] T1: Mainly used for unit exhaust temperature monitoring and forming a mutual confirmation relationship with T2. When the difference between T1 and T2 exceeds the theoretical temperature drop range of the system (this temperature drop range is a theoretical value calculated based on the length, diameter, insulation material performance and thickness of the system main flue. Of course, in the system design process, the theoretical difference between T1 and T2 should be minimized as much as possible under economic feasibility), there are two situations: (1) Normal situation: During operation, due to the attenuation of material performance, the difference gradually decreases. This process is a process calculated in months or years and is a normal phenomenon. During this process of material performance attenuation, the computer preset parameters of the hot air furnace need to be corrected regularly, which is part of the normal maintenance of the system. (2) Abnormal situation: The difference suddenly increases beyond a certain range. At this time, the control system needs to alarm. This situation is mostly caused by flue leakage or the erroneous opening of any valve of D1 or Q1. Of course, T1 also has the function of providing data for the temperature adjustment of the hot air furnace, but it is not the main one. The hot air furnace is mainly adjusted by T2 and T3.

[0041] T2: Mainly used to interlock with the hot air stove computer to adjust the hot air stove combustion gun load to stabilize the temperature in the spray tower. At the same time, T2 also needs to be verified with T1 to eliminate system failures, as described in the previous paragraph.

[0042] T3: Temperature monitoring inside the spray tower is used to determine whether the hot blast furnace combustion gun is increasing or decreasing the load.

[0043] P1: A safety element to ensure that the generator set is not damaged by negative pressure, interlocked with Q1. At the same time, it can be mutually verified with P2 to exclude damage to the flue system or accidental opening of the valve, the same as T1.

[0044] P2: Feedback of measured value, confirmed with P1. In addition, feedback of sudden change of rear pressure, such as failure of the exhaust fan of the spray tower but no error report, can be identified and alarmed by the sudden decrease or disappearance of negative pressure at P2.

[0045] F1: Feedback to the hot air furnace computer together with T2 measurement value, interlocking to adjust the hot air furnace combustion gun load to stabilize the temperature in the spray tower. In addition, it can also assist the heat supply settlement between energy companies and ceramic enterprises, that is, calculate the heat supply through real-time T2 and F1. However, due to the low accuracy of F1, the heat supply calculated in this way is only used as a reference for settlement.

[0046] The main control device adjusts the action of the control component according to the control strategy based on the F1, T1, P1, T2, P2 parameter data and other operating data of the current spray tower, hot blast stove, and natural gas generator set. The control component is controlled by the main control device to control the corresponding valve to change state in an orderly manner. It is used to control the opening of the main flue and the closing of the bypass chimney, or the closing of the main flue and the opening of the bypass chimney. It is also used to control the opening of the branch pipeline under special circumstances to match it with the required working conditions of the natural gas generator set, hot blast stove, and spray tower, and realize working condition switching to ensure the stable operation of the entire system under different working conditions. For example Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8 shown.

[0047] Working condition 1: The flue gas discharged from the natural gas generator set and the hot air discharged from the hot blast furnace are mixed at the connection port and then transported to the inside of the spray tower for hot air supply. This working condition is also the main operating mode of this system.

[0048] like Figure 2 As shown, it starts with the natural gas generator set, hot air furnace, and spray tower not started. During the startup process, the startup status needs to be confirmed first. D1 is in the open state, D2, D3, and Q1 are in the closed state, and the hot air furnace and spray tower are ready. When the natural gas generator set is started, it needs to be isolated from the rear spray tower first, so the bypass chimney (ie D1) needs to be connected to the atmosphere. Q1 should be kept closed for a long time (branch pipeline closed) to prevent air from leaking into the system. When shutting down or stopping due to a fault, only P1 needs to be interlocked. P1 reaches the lower limit of the allowable pressure at the exhaust end of the generator set before Q1 is interlocked and opened quickly.

[0049] After the status is confirmed, a start signal is sent to the natural gas generator set, and the natural gas generator set starts to start. It can only be slowly connected to the system after the load is stabilized to 70%. The reason is that the unit has requirements for the back pressure at the rear end, and the back pressure that can be tolerated at the start is relatively small. After the load is increased to 70%, D2 is turned on, and after it is fully opened, D3 is turned on; the opening status of D3 is determined. If a fault is reported, the system is in the current state and the fault is eliminated (if it is a major fault (such as the generator cannot operate normally, or D3 cannot be opened normally at all, etc.), the system will be completely stopped according to the corresponding safety regulations). After the fault is eliminated, the current natural gas generator set is running stably, and the load continues to be increased to full load, and then D1 is closed. After it is fully closed, it is ensured that the natural gas generator set is running stably.

[0050] The spray tower is started in two stages. The first stage start-up may include starting the exhaust fan, spraying water in the tower, and drying the tower. After the flue gas from the natural gas generator set is connected (that is, after D2 and D3 are turned on), the first stage start-up of the spray tower begins to dry the tower. It is judged that the spray tower drying is completed and the natural gas generator set is running stably. At this time, the second stage start-up of the spray tower is continued, that is, the hot air furnace is started until the spray tower is running stably as a whole. The operation of the spray tower requires the temperature to be controlled within the range of ±5℃.

[0051] Specifically, the hot blast furnace is started, and the load is gradually increased according to the preset load increase strategy until the operation is stable, that is, the load is increased according to the hot blast furnace output load calculated according to the exhaust gas temperature when the unit is fully loaded. During the load increase process, the hot blast furnace determines and adjusts the output load target value according to F1, T2, and T3 through the main control device, so that T3 reaches the required temperature range of the spray tower; when the hot blast furnace is running stably, the spray tower is running stably, and the unit is fully loaded, it is confirmed that the current operation of the entire system is stable, and thus enters the working condition 1 in which the natural gas generator set and the hot blast furnace simultaneously supply hot air to the spray tower, and then the hot blast furnace fine-tunes the temperature according to T3. During the load increase process, the hot blast furnace determines and adjusts the load to T3 to reach the required range with F1, T2 and T3, and then fine-tunes the temperature with T3 after the common supply system is running stably. In this way, the temperature regulation of the common supply system is more direct and rapid. The flue gas emission of the natural gas engine group is relatively stable. Although the flue gas temperature fluctuates within the range of about ±10°C, due to the certain distance between the main flue and the material, a slight fluctuation will not be so drastic. Therefore, after the system runs stably, the hot air furnace can be fine-tuned according to T3 to meet the temperature requirements.

[0052] In order to improve the accuracy and speed of temperature adjustment, T1, T2 and F1 can also be continuously monitored while adjusting the hot blast furnace according to T3. When T1 exceeds the preset alarm threshold, for example, the fluctuation range exceeds ±10°C, it means that the flue gas temperature fluctuates greatly. Immediately restore and adjust the output load target value according to F1, T2 and T3, so as to predict temperature changes in advance and avoid the adjustment lag problem caused by load adjustment according to T3 in the case of large fluctuations. After T1 and T3 return to the stable range, resume fine-tuning according to T3.

[0053] The stable operation of the spray tower is very important. The whole system emphasizes stability because the powder dried in the spray tower is an important production raw material. The value of a furnace of powder is millions of yuan. Once the working condition is unstable, the powder parameters will not meet the standard, resulting in losses. Unit load adjustment will cause changes in exhaust temperature (load reduction, reduced exhaust volume but increased exhaust temperature). At this time, T2, T3, and F1 need to be fed back to the hot air furnace computer to adjust the output load of the hot air furnace. Therefore, under the condition of stable operation, if Figure 3 As shown in the figure, it is the working condition switching from working condition 1 to unit load adjustment. When the unit sends a load adjustment signal, the spray tower receives the signal and determines whether it meets the supply switching conditions. If not, the unit load adjustment is rejected, and the unit continues to maintain the original full load supply; if satisfied, it is confirmed, and the spray tower performs material conservation operation while the unit performs load adjustment. T3 feeds back the current temperature of the spray tower to the hot blast furnace, and the hot blast furnace feeds back to the hot blast furnace computer based on T2, T3, and F1 to adjust the output load of the hot blast furnace until the unit, spray tower and hot blast furnace operate stably and the working condition switching is completed.

[0054] In the case of stable operation, if Figure 2 As shown in the figure, it is the working condition switching from working condition 1 to normal shutdown of the unit. When the unit sends a unit shutdown signal, the spray tower receives the signal and determines whether it meets the supply switching conditions. If not, the unit shutdown is rejected, and the unit continues to supply at full load; if satisfied, the hot blast furnace starts to add load to independently supply the spray tower (the load is added at this time, and the adjustment is based on the feedback from T3 to the hot blast furnace computer), and D1 is turned on at the same time. After it is fully opened, the natural gas generator set shuts down normally. When the shutdown operation begins, D3 is closed (at this time, D1 is already opened, and the unit exhaust has been connected to the atmosphere. D3 should be used to cut off and isolate the unit from the spray tower-hot blast furnace system as soon as possible). After it is fully closed, D2 is closed. After it is fully closed, the working condition switching ends. At this time, the unit shuts down, and the hot blast furnace independently supplies the spray tower.

[0055] In the case of stable operation, if Figure 4As shown in the figure, the working condition switching from working condition 1 to unit failure emergency stop, the unit sends a fault signal, the spray tower sound and light alarm, T3 feeds back the current temperature of the spray tower to the hot blast furnace, the hot blast furnace adjusts the temperature of the combustion gun based on T3 calculation, and implements material conservation treatment; the spray tower sound and light alarm is turned on at the same time, and after it is fully opened, D3 is closed, and after it is fully closed, D2 is closed; while D1 is turned on, if P1 detects that the pressure is lower than the minimum allowable back pressure of the unit, Q1 is interlocked to open; until the spray tower and hot blast furnace run stably, the working condition switching is completed. In addition, when the unit fails, other sound and light alarms are also made through the main control unit, such as the sound and light alarm in the control room. The process of this working condition switching is different from the normal shutdown condition of the unit. In the control process, the rejection and confirmation links of the spray tower are reduced, and the hot blast furnace is directly used to supply the spray tower alone, which emphasizes the rapid and stable working condition switching and the rapid and accurate temperature adjustment.

[0056] In the case of stable operation, if Figure 5 As shown, it is the working condition switching from working condition 1 to spray tower failure. When the spray tower fails, the hot air furnace starts the corresponding stop operation after receiving the fault signal and quickly enters the shutdown state; at the same time, D1 is turned on, and after it is fully opened, the current state of the unit is confirmed, and D3 is closed. During the process of closing D3, the current state of the unit is confirmed. After D3 is fully closed, D2 is closed to confirm the current state of the unit. The current state confirmation of the unit requires judging whether the unit is directly shut down or continues to run independently after being disconnected from the rear-end spray tower system; when D1 is turned on, if P1 is lower than the allowable value of the unit, Q1 is turned on; until the unit runs independently and stably or shuts down normally, D2 is fully closed, and the working condition switching is completed. The failure of the spray tower itself requires more stable and fast switching than the failure of the unit.

[0057] like Figure 6 As shown, the operating condition is switched from the complete shutdown of the system to the flue maintenance. The shutdown status of the unit is confirmed, and the unit start button is locked. At the same time, the shutdown status of the spray tower and the hot blast furnace is confirmed, and the start buttons of the spray tower and the hot blast furnace are locked. After all locks are confirmed, D1, D2 and D3 are turned on to carry out flue maintenance. After the maintenance is completed, all locks are released and the operating condition switching is completed.

[0058] like Figure 7 and Figure 8 As shown, before the natural gas generator set is operated alone, and the spray tower-hot air furnace is operated alone, confirm that D1 is turned on, and D2 and D3 are turned off. After this condition is met, the corresponding startup process is carried out. The respective startup processes have been described in detail above and will not be repeated here.

[0059] The present embodiment provides a non-supplementary combustion type natural gas distributed energy waste heat utilization control system, which adopts a non-supplementary combustion form and directly utilizes the tail flue gas of the natural gas generator set, making the most of the company's existing resources, with small investment and low transformation cost. On the basis of retaining the original hot blast furnace and spray tower structure, the natural gas generator set is connected to the connection port of the hot blast furnace and the spray tower through an independent flue, and the flue gas of the natural gas generator set and the hot air of the hot blast furnace are mixed at the connection port and then sent into the spray tower. This is an effective and economically feasible transformation method in the existing ceramic production equipment layout.

[0060] Through the bypass chimney and branch pipelines set on the main flue, as well as the combined configuration and position layout of valves and data acquisition components, stable switching of various working conditions can be achieved with simple control logic to ensure stable production of the enterprise (ceramic enterprises produce in three shifts without stopping the furnace, and have extremely high requirements for system stability); on the basis of ensuring stable switching of system working conditions, data acquisition components are added with reasonable layout to ensure the accuracy, rapidity and stability of temperature adjustment. The main control device adjusts the hot air parameters of the hot blast furnace based on the high-temperature flue gas flow acquisition component F1, the second temperature acquisition component T2, and the tower top temperature acquisition component T3, which is convenient for the hot blast furnace Adjust the combustion gun in real time to maintain the temperature in the spray tower stable; the main control device also makes an abnormal judgment based on the temperature data difference measured by the first temperature acquisition component T1 and the second temperature acquisition component T2; the main control device also makes an abnormal judgment based on the pressure data difference measured by the first pressure acquisition component P1 and the second pressure acquisition component P2; the first pressure sensor P1 and the fourth valve Q1 are interlocked and controlled by the main control device. Because the spray tower has a negative pressure source, it may cause negative pressure at the exhaust port of the unit under special circumstances, which may cause serious damage to the unit. Therefore, an interlocking protection measure is formed to protect the unit from negative pressure to solve the above problems. In addition, this solution can also provide underlying data and algorithm support for enterprises to realize intelligent energy carbon management through multi-point data collection and analysis of the system, and assist in heat supply settlement between energy companies and ceramic enterprises. Based on this, the setting of the structure of this solution is more conducive to the accuracy of spray tower temperature control and the stability of switching between different working conditions of the entire system.

[0061] Embodiment 2

[0062] On the basis of the first embodiment, the hot blast furnace is provided with at least one load-adjustable combustion gun; the temperature in the conventional hot blast furnace is adjusted by increasing or decreasing the number of combustion guns. When the combustion gun is in use, the temperature of the spray cannot be adjusted in real time with the operation of the system, so the adjustment accuracy needs to be improved.

[0063] This scheme sets at least one load-adjustable burner, which is mainly adjusted by adjusting the load of a single burner and supplemented by increasing or decreasing the number of burners. That is, the temperature rise of the burner during the operating condition adjustment process is mainly load adjustment, that is, the temperature is mainly adjusted by one burner, unless the load of the unit drops sharply and the load adjustment of one burner cannot meet the requirement, then consider adding one or more burners, so that the temperature adjustment of the whole system adds an adjustable point, further improving the accuracy of temperature adjustment. In addition, real-time adjustment through a load-adjustable burner makes temperature control simpler and more convenient than adding multiple burners, and the adjustment process is faster and more stable.

[0064] Embodiment 3

[0065] On the basis of embodiments one and two, a non-supplementary combustion type natural gas distributed energy waste heat utilization control system also includes a fuel supply device connected to the supply input end of the natural gas generator set. The fuel supply device measures, stabilizes (or regulates) the pressure of the natural gas supplied from the municipal pipeline, and boosts the pressure to the pressure required by the natural gas generator set before delivering it to the natural gas generator set for use.

[0066] The system also includes a compressed air supply device connected to the valves belonging to the natural gas generator set and the fourth valve to provide a valve control power source therefor.

[0067] The system also includes a flue gas monitoring device installed on the bypass chimney, and the compressed air supply device is also connected to the flue gas monitoring device on the bypass chimney to provide it with a purge air source for the sampling facility. The compressed air supply device uses an air compressor, a cold dryer, and a buffer tank to prepare clean compressed air to provide a valve power source and purge.

[0068] Of course, the natural gas generator set is also connected to the electrical system, security, fire protection and other systems, and the layout and setting are made according to actual needs to ensure the normal and stable operation of the natural gas generator set when it operates independently without heating to generate electricity.

[0069] Of course, the natural gas generator set is also connected to the electrical system, security, fire protection and other systems, and the layout and setting are made according to actual needs to ensure the normal and stable operation of the natural gas generator set when it operates independently without heating to generate electricity.

[0070] The above is only an embodiment of the utility model. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field are aware of all the common technical knowledge in the technical field of the utility model before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement the scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for the technicians in this field, without departing from the structure of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent.

Claims

1. A non-supplementary natural gas distributed energy waste heat utilization control system, characterized in that: Including main flue, natural gas generator set, hot air furnace, spray tower, main control device, data acquisition components and control components; The hot blast furnace is connected to the spray tower and has a connection port on the connection path; the smoke exhaust end of the natural gas generator set is connected to the connection port through the main flue; a bypass chimney is provided on the main flue near the natural gas generator set; a branch pipeline connected to the atmosphere is provided on the main flue near the connection port; the control component is connected to the main flue, the bypass chimney and the branch pipeline; the data acquisition component is installed at the smoke exhaust end, the connection port and the spray tower of the natural gas generator set; The main control device is communicatively connected with the natural gas generator set, hot blast furnace, spray tower, data acquisition component and control component; the control component is controlled by the main control device, and is used to control the opening of the main flue and the closing of the bypass chimney, control the closing of the main flue and the opening of the bypass chimney, and also to control the opening of the branch pipeline under special circumstances, so as to match the required working conditions of the natural gas generator set, hot blast furnace and spray tower.

2. According to claim 1, a non-supplementary combustion type natural gas distributed energy waste heat utilization control system is characterized in that: The control assembly includes a first valve arranged on the bypass chimney, a second valve and a third valve arranged on the main flue and located between the bypass chimney and the branch pipeline, and a fourth valve arranged on the branch pipeline.

3. According to claim 2, a non-supplementary combustion type natural gas distributed energy waste heat utilization control system is characterized in that: The second valve is located between the bypass chimney and the third valve.

4. According to claim 2, a non-supplementary combustion type natural gas distributed energy waste heat utilization control system is characterized in that: The second valve and the third valve have a first distance, and the first distance satisfies that when the second valve and the third valve are fully opened, the distance between the two valve plates is not less than 300 mm.

5. According to claim 2, a non-supplementary combustion type natural gas distributed energy waste heat utilization control system is characterized in that: The first valve and the second valve are fully open and fully closed electric high-temperature flue gas butterfly valves, the third valve is a fully open and fully closed electric high-temperature flue gas butterfly valve or a graded opening adjustable electric high-temperature flue gas butterfly valve, and the fourth valve is a fully open and fully closed pneumatic high-temperature flue gas butterfly valve.

6. According to claim 1, a non-supplementary combustion type natural gas distributed energy waste heat utilization control system is characterized in that: The data acquisition component includes a first temperature acquisition component and a high-temperature flue gas flow acquisition component arranged at the exhaust port of the natural gas generator set, a second temperature acquisition component arranged at the connection port, and a tower top temperature acquisition component arranged in the spray tower.

7. According to claim 2, a non-supplementary combustion type natural gas distributed energy waste heat utilization control system is characterized in that: The data acquisition component includes a first pressure acquisition component arranged at the exhaust port of the natural gas generator set and a second pressure acquisition component arranged at the connection port; the first pressure acquisition component and the fourth valve are interlocked and controlled by the main control device.

8. According to claim 1, a non-supplementary combustion type natural gas distributed energy waste heat utilization control system is characterized in that: The hot blast stove is provided with at least one load-adjustable combustion gun.

9. The non-supplementary combustion type natural gas distributed energy waste heat utilization control system according to claim 1 is characterized in that: The natural gas generator set is a gas turbine.

10. A non-supplementary combustion type natural gas distributed energy waste heat utilization control system according to claim 2, characterized in that: It also includes a fuel supply device connected to the supply input end of the natural gas generator set, a flue gas monitoring device installed on the bypass chimney, and a compressed air supply device connected to the valve belonging to the natural gas generator set, the fourth valve and the flue gas monitoring device.

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