Storage tank overflow and leakage detection system and method
By combining the liquid level and flow detection module in the tank detection system, the storage tank leakage or overflow is determined by using the equivalent volume dynamic change rate and equivalent instantaneous flow rate, the problem of difficult to effectively detect the storage tank leakage or overflow in the prior art is solved, early detection and liquid level instrument fault diagnosis are achieved, and the accuracy and reliability of the detection are improved.
Patent Information
- Application Number
- CN202510155489.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-12
- Publication Date
- 2025-06-06
AI Technical Summary
The prior art is difficult to effectively determine whether there is leakage or overflow in the storage tank, especially when the liquid level changes dynamically, it is difficult to distinguish between leakage and overflow. Moreover, the selection surface of the liquid level instrument is narrow, which is prone to failure, resulting in leakage or overflow not being discovered in time.
The tank overflow and leakage detection system is adopted, including the liquid level detection module, the flow detection module and the diagnostic module. By obtaining the tank liquid level height, the dynamic instantaneous flow of the output tube and the input tube, combining the equivalent volume dynamic change rate and the equivalent instantaneous flow, the leakage or overflow of the storage tank is judged, and the valve group is controlled and cut off through the interlocking cut-off module to prevent overflow.
It realizes timely detection of early leakage in the storage tank, provides enterprises with time for early intervention, reduces safety hazards and environmental impacts caused by leakage or overflow, and can diagnose liquid level instrument failures, improving the accuracy and reliability of detection.
Smart Images
Figure CN120097269A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of storage tank detection, and in particular to a storage tank overflow and leakage detection system and method. Background Art
[0002] In the chemical and petrochemical fields, there are a large number of hazardous chemicals and energy storage and transportation facilities, which include different types of storage tanks, including spherical tanks, vertical tanks, horizontal tanks, and above-ground tanks and underground tanks. Tank groups sometimes involve flammable and toxic media, which can have a great impact on the environment once leaked, and cause huge casualties due to explosions and poisoning.
[0003] According to the requirements of the National Emergency Management Risk Hazard Inspection Guidelines, the inspection frequency of general chemical plants shall not be less than once every two hours, and the inspection frequency of two key and one major hazardous chemical enterprises shall usually not be less than once an hour. For most working conditions, production is continuous, and the feeding and discharging of storage tanks are dynamic. Leakages at this stage are extremely difficult to detect. An inspection time interval of one to two hours will result in a lag in the detection of leaks, thereby missing the best time for emergency response. In particular, leakage of liquids in underground storage tanks is more difficult to detect and brings greater potential dangers. Therefore, it is particularly important to detect tank leaks as early as possible.
[0004] At present, the industry generally adopts the method of detecting the height of the liquid level with a level gauge and then closing the feed valve through the control system interlock to avoid overflow. If a single level gauge is used, the interlock failure may cause the tank to overflow due to the failure of the level gauge. Usually, two to three level gauges are set according to different liquid storage tank group application scenarios. This is an effective fault-tolerant means of level detection, ensuring the normal operation of the instrument system and effectively preventing overflow accidents during the tank filling process.
[0005] However, when the tank is being loaded and unloaded, the liquid level changes dynamically with the change of the filling volume. For leakage of the tank and the pipes and flanges connected to it, the dynamic change of the liquid level cannot directly reflect whether the tank is leaking. When the tank is not being loaded and unloaded, for leakage of the pipe flange connection or the tank body, it is not easy to judge whether there is a leakage through slight changes in the liquid level, especially for horizontal tanks, spherical tanks, or other vertical tanks with non-cylindrical structures. It is even more difficult to judge whether there is a leakage through slight changes in the liquid level.
[0006] In addition, due to the large differences in the properties of different liquid materials, such as low dielectric constant, foam, vapor-liquid mixed phase layer and interference factors, the selection of liquid level instruments becomes narrower or even it is impossible to choose suitable instruments. In addition, changes in material properties (such as gasification of the medium during loading and unloading), material corrosion to the instrument, and environmental factors, even redundantly configured liquid level meters will have the risk of common cause failure or common mode failure, resulting in the inability to detect tank leaks normally or causing the overflow protection interlock to fail. Summary of the invention
[0007] Based on the technical problems existing in the background technology, the present invention proposes a tank overflow and leakage detection system and method, which can effectively determine whether there is a leak or overflow in the tank, determine the early leakage of the tank, buy sufficient time for the enterprise to intervene early, judge the severity of the leakage and overflow of the tank, and provide a basis for the owner's emergency response. When there is an overflow risk, the equipment can be prevented from overflowing through interlocking, and the fault diagnosis of the liquid level instrument can also be realized.
[0008] The present invention provides a storage tank overflow and leakage detection system, comprising: A liquid level detection module, used to obtain the liquid level heights of at least two positions of each storage tank of the storage tank group, and determine the volume of the liquid in the storage tank according to the liquid level heights; A flow detection module is used to obtain the dynamic instantaneous flow of the output pipe and input pipe of the storage tank group; The diagnostic module is used to judge the leakage / overflow of the tank according to the cumulative flow of the liquid in a time period and the change in the volume of the liquid in the tank during the time period, or to judge the leakage / overflow of the tank according to the dynamic change rate of the equivalent volume of the liquid in the tank and the equivalent instantaneous flow.
[0009] Preferably, it also includes an interlocking cut-off module and a cut-off valve group arranged at the inlet and outlet of the storage tank, wherein the interlocking cut-off module is used to control the opening and closing of the cut-off valve group according to the leakage / overflow situation of the storage tank determined by the diagnosis module, and to send out a corresponding alarm signal.
[0010] Preferably, the flow detection module includes an inlet and outlet flow meter and a flow data processing module, and the flow data processing module is used to calculate the cumulative flow and equivalent instantaneous flow of the liquid within a time period according to the dynamic instantaneous flow of the flow meter, and feed the result back to the diagnosis module.
[0011] Preferably, the liquid level detection module includes at least two liquid level gauges and a liquid level data processing module, and the liquid level data processing module is used to calculate the volume change and the dynamic change rate of the equivalent volume of the liquid in the storage tank within a time period according to the liquid level height detected by the liquid level gauge, and feed the results back to the diagnosis module.
[0012] The present invention proposes a method for detecting overflow and leakage of a storage tank, and the method steps are as follows: The liquid level detection module is used to obtain the liquid level height at different positions of each storage tank in the storage tank group, and the volume of the liquid in the storage tank is determined according to the liquid level height; The dynamic instantaneous flow of the output pipe and input pipe of the storage tank group is obtained through the flow detection module; The diagnostic module determines the leakage / overflow of the tank based on the cumulative flow of the liquid in a time period and the change in the volume of the liquid in the tank during the time period, or determines the leakage / overflow of the tank based on the dynamic change rate of the equivalent volume of the liquid in the tank and the equivalent instantaneous flow.
[0013] Beneficial technical effects of the present invention: The present invention uses the method of equivalent volume dynamic change rate and equivalent instantaneous flow rate to judge, diagnose overflow, leakage and liquid level meter failure of the storage tank group, and interlocks and closes the inlet and outlet shut-off valves according to the state of the storage tank; because the instantaneous flow of the flow meter is affected by the change of pipeline pressure and the change of valve opening, the instantaneous value of the pulse effect flow of the pump group is a dynamic value with certain fluctuations, and regardless of whether the storage tank is regular, the liquid level change of the storage tank cannot reflect the rate of change of volume per unit time. The present invention application uses a method of equivalent instantaneous flow rate and a method of equivalent volume dynamic change rate to jointly judge, overcome the interference caused by instantaneous flow fluctuations, so that this measurement scheme can judge the occurrence of leakage or overflow without increasing additional investment, and can also judge whether the liquid level meter has a fault. Due to the use of the detection method of equivalent volume dynamic change rate and equivalent instantaneous flow rate in a short period of time, the detection system of the present invention is conducive to the early leakage detection of storage tanks, and it is sufficient time for enterprises to intervene early, especially for the prevention of early leakage and overflow problems of underground storage tanks. It has a more positive significance.
[0014] In addition, since the severity of the leakage is judged by assisting the macroscopic cumulative flow and volume changes, the present invention can judge the leakage and overflow degree of the storage tank; since the interlocking logic module is adopted, the leakage and overflow of the storage tank group can be alarmed and interlocked, and an alarm can be issued to remind the operator; since logical judgment is adopted, it can also be diagnosed whether the leakage occurs in the storage tank group body, the feed pipeline or the discharge pipeline. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a structural schematic diagram of the storage tank overflow and leakage detection system proposed by the present invention. DETAILED DESCRIPTION
[0016] The present invention will be further explained below in conjunction with specific embodiments.
[0017] Reference Figure 1 , this embodiment includes n Tank group consisting of TK 1~ TKn , connecting pipeline LINE 01~04、 LINE 11~ LINEn 1. LINE 12~ LINEn 2. LINE 13~ LINEn 3.LINE 14~ LINEn 4 and two level gauges on each tank ( LT 11~ LTn 1. LT 12~ LTn 2) and the corresponding liquid level interlock alarm ( LSA 11~ LSAn 1. LSAn 1~ LSAn 2) Flowmeter located on the input and output pipelines ( FT 01. FT 02) and the corresponding cumulative flow display FIQ 01. FIQ 02. Inlet and outlet shut-off valves for each tank XV 11~ XVn 1. XV 12~ XVn 2 and interlocking function I 11~ In 1. I 12~ In 2 (realized by DCS control system or other control systems). LSA 11~ LSAn 1. LSA 12~ LSAn 2. I 11~ In 1. I 12~ In 2. FIQ 01. FIQ 02 (flow indication accumulation) are all realized in the DCS system. LT 11~ LTn 1. LT 12~ LTn 2 and flow meter FT 01. FT The signal of 02 is transmitted to the DCS system with the cable as the transmission medium and the standard 4~20mA or bus signal.
[0018] First feed line LINE 01With flow meter FT 01 connected ( Figure 1 Shown is a mass flow meter MF for explanation), FT 01Export and pipeline LINE 02 connected, LINE 02Exports are respectively LINE 12~ LINEn 2 connected, LINE 12~ LINEn 2. The pipeline outlet is cut off from the inlet valve XV11~ XVn 1 connected, inlet cut-off valve XV 11~ XVn 1 respectively with LINE 11~ LINEn 1 connected, LINE 11~ LINEn 1 and each storage tank TK 1~ TKn Connected. Storage tank TK 1~ TKn Two level gauges are set on each LT 11~ LTn 1. LT 12~ LTn 2. Storage tank group TK 1~ TKn Outlet and pipeline LINE 13~ LINEn 3 connected, pipeline LINE13~ LINEn 3 and outlet cut-off valve XV 12~ XVn 2 connected, outlet cut-off valve XV 12~ XVn 2 and pipeline LINE 14~ LINEn 4 connected, pipeline LINE 14~ LINEn 4 and again LINE 04 connected, LINE 04 and then the exit FT 02Mass flow meter connected, finally FT 02 and export pipeline LINE 03 connected. FIQ 01 is flow meter FT 01The detected flow is displayed in the control system. FIQ 02 is the flow meter FT 02 The detected flow is displayed in the control system, where F Indicates flow rate, I Indicates the indication function. Q Indicates the accumulation function. LT 11. LT 12~ LTn 1. LTn 2. Use standard 4~20mA current signal or bus signal to transmit to the control system LI 11. LI 12~ LIn 1. LIn 2 indicates the corresponding level gauge LT 11. LT 12~ LTn 1. LTn2. The detected liquid level is displayed in the control system. The three-way valve with an S mark on the inlet and outlet cut-off valve represents the electrical control element (solenoid valve) of the cut-off valve. When the control system is triggered, the excitation / de-excitation of the electrical element controls the opening and closing of the cut-off valve. LSA 11~ LSAn 1. LSA 12~ LSAn 2 represents the liquid level interlock alarm function in the control system. When the algorithm confirms that a tank X is leaking, the alarm is triggered. When the algorithm confirms that a tank X is about to overflow or has overflowed, the trigger signal is sent to the interlock function. Ix 1. Ix 2. And output signal to the cut-off valve to cut off the storage tank.
[0019] The flow detection module (flow meter) of this embodiment FT 01 and FT 02), used to obtain the instantaneous flow rate of the output pipe and input pipe of the storage tank within a period of time; The liquid level detection module (liquid level meter) of this embodiment LT 11~ LTn 1 and LT 12~ LTn 2) It is used to obtain the liquid level at different positions of the storage tank, and then calculate the volume of the liquid in the storage tank according to the detected liquid level data. Regarding the correspondence between the liquid volume and the liquid level in the storage tank, different storage tank shapes have different calculation methods, and the relationship between the two can be determined using the existing method; the two liquid level gauges can be of the same type or different types, and the measurement values of the two liquid level gauges may even have deviations. Since the two liquid level gauges are compared and corroborated with each other, unnecessary false alarms, false stops, or no alarms or stops when alarms are required due to failure of a single liquid level gauge can be avoided.
[0020] Specifically, taking vertical barrel storage tanks, spherical tanks and horizontal cylindrical storage tanks (horizontal tanks for short) as examples, the functions of their volumes and liquid level heights are as follows: Vertical barrel storage tank volume formula: in, x is the liquid level height; r It is the bottom radius of vertical barrel storage tank.
[0021] Spherical tank volume formula: in, x is the liquid level height; R is the radius of the spherical tank.
[0022] Horizontal tank volume formula: in, is the cross section of the cylinder; is the cross-sectional area of the head; x is the liquid level height; r is the radius of the cylinder; R is the radius of the head, L The length of the cylinder.
[0023] Storage tank TKn Liquid level gauge LTn 1. LTn 2 Detect the real-time liquid level x .
[0024] The diagnosis module of this embodiment is used to determine the leakage / overflow point of the storage tank according to the accumulated flow rate in a time period and the change of the liquid level at different positions of the storage tank in the time period.
[0025] Specifically, the diagnostic module mainly obtains the equivalent instantaneous flow of the output pipe and the input pipe by accumulating the flow, obtains the equivalent volume change rate at different positions by the liquid level change at different positions of the tank, and compares the equivalent instantaneous flow of the output pipe and the input pipe with the equivalent volume change rate at different positions to determine the leakage / overflow point of the tank. The equivalent volume change rate and the equivalent instantaneous flow can be calculated using existing technology. The equivalent instantaneous flow adopted overcomes the interference caused by the dynamic fluctuation of the system feed and discharge.
[0026] For example, the equivalent instantaneous flow FIn ( t )avg( t 1~ t 2) in a limited and extremely short period of time) is calculated as follows: Among them, the inlet and outlet flow difference of the storage tank FIn ( t )= FI 01( t )- FI 02( t ).
[0027] No. n The equivalent volume change rate d of the No. 1 and No. 2 level gauges in each storage tank VIn 1( t )avg、d VIn 2( t )avg( t 1~ t 2) in a limited and extremely short period of time) is calculated as follows: in, Vn 1 is a storage tank TKn Inside LTn 1Liquid level detected by the level gaugex The corresponding volume V ( x ), Vn 1 t 1 that is Vn 1 in t Volume at 1 moment V ( x )、 Vn 1 t 2 that is Vn 1 in t Volume at 2 moments V ( x ); Similarly, Vn 2 for storage tank TKn Inside LTn 2 Liquid level detected by the liquid level gauge x The corresponding volume V ( x ), Vn 2 t 1 that is Vn 2 in t Volume at 1 moment V ( x )、 Vn 2 t 2 that is Vn 2 in t Volume at 2 moments V ( x ).
[0028] Storage tank TKn The level gauge measures the real-time height x , cross-sectional area of liquid in the tank f ( x ) is the height of the liquid level x The function of V ( x ) is a volume function calculated from the liquid level height, , x That is n Level gauge on tank LTn 1. LTn 2 Detected liquid level height.
[0029] The detection system diagnosis and alarm interlocking of the present invention are as follows: 1) There is no material in or out of the storage tank TKn, the inlet valve XVn1 and the outlet valve XVn2 of the storage tank TKn are closed, ∫FIn(t)dt=0, and the leakage of the non-filling process of the storage tank is detected at this time; when the valve is closed, FIn ( t )avg=0,d VIn 1( t )avg = dVIn 2( t )avg>0 or ∫ Fn ( t )d t =0,Δ Vn 1( t )=Δ Vn 2( t )>0, it indicates that the tank is leaking.
[0030] 2) The storage tank TKn only feeds but does not discharge. The inlet valve XVn1 of the storage tank TKn is open, and the outlet valve XVn2 is closed. ∫FIn(t)dt=∫FI01(t)dt. At this time, the leakage of the storage tank is detected during the feeding process. When the valve is closed, FIn ( t )avg=0,d VIn 1( t )avg = d VIn 2( t )avg>0 or ∫ Fn ( t )d t =0,Δ Vn 1( t )=Δ Vn 2( t )>0, it indicates that the tank is leaking; when the valve is closed, FIn ( t )avg>0,d VIn 1( t )avg = d VIn 2( t )avg = 0 or ∫ Fn ( t )d t >0,Δ Vn 1( t )=Δ Vn 2( t ) = 0, indicating that the tank feed pipeline is leaking; when the valve is closed, FIn ( t )avg>0,d VIn 1( t )avg = d VIn 2( t )avg>0 or ∫ Fn ( t )d t >0,Δ Vn 1( t )=Δ Vn 2( t )>0, it indicates that both the feed pipeline and the tank are leaking.
[0031] 3) The storage tank TKn only discharges but does not feed. The inlet valve XVn1 of the storage tank TKn is closed, and the outlet valve XVn2 is opened. ∫FIn(t)dt=-∫FI02(t)dt. At this time, the leakage of the storage tank is detected during the discharge process. When the valve is closed, FIn ( t )avg=0,d VIn 1( t )avg = d VIn 2( t )avg>0 or ∫ Fn ( t )d t =0,Δ Vn 1( t )=Δ Vn 2( t )>0, it indicates that the tank is leaking; when the valve is closed, FIn ( t )avg>0,d VIn 1( t )avg = d VIn 2( t )avg = 0 or ∫ Fn ( t )d t >0,Δ Vn 1( t )=Δ Vn 2( t ) = 0, indicating that the tank discharge pipeline is leaking; when the valve is closed, FIn ( t )avg>0,d VIn 1( t )avg = d VIn 2( t )avg>0 or ∫ Fn ( t )d t >0,Δ Vn 1( t )=Δ Vn 2( t )>0, it indicates that both the discharge pipeline and the tank are leaking.
[0032] 4) Storage tank TKn is simultaneously fed and discharged (this operating condition is rare), the inlet valve XVn1 of storage tank TKn is opened, the outlet valve XVn2 is opened, ∫FIn(t)dt=∫FI02(t)-FI02(t)dt, at this time, the leakage of the storage tank during the feeding and discharging process is detected; when the valve is closed, FIn ( t )avg=0,d VIn 1( t )avg = d VIn 2( t)avg>0 or ∫ Fn ( t )d t =0,Δ Vn 1( t )=Δ Vn 2( t )>0, indicating that the tank is leaking; when the valve is closed, the feed flow meter FT1 ( t )avg>0,d VIn 1( t )avg = d VIn 2( t )avg = 0 or ∫ Fn ( t )d t >0,Δ Vn 1( t )=Δ Vn 2( t ) = 0, feed flow meter FT2 ( t )avg>0 indicates that the discharge pipeline of the storage tank is leaking; when the valve is closed, FIn ( t )avg>0,d VIn 1( t )avg = d VIn 2( t )avg>0 or ∫ Fn ( t )d t >0,Δ Vn 1( t )=Δ Vn 2( t )>0, it indicates that both the inlet and outlet pipelines and the tank are leaking.
[0033] The present invention uses the method of equivalent volume dynamic change rate and equivalent instantaneous flow rate to judge and diagnose overflow, leakage and liquid level meter failure of the storage tank group, and interlocks and closes the inlet and outlet shut-off valves according to the state of the storage tank, and at the same time assists in judging the severity of the leakage by the macroscopic cumulative flow and volume change, and performs alarm interlock protection on the storage tank group. The detection system of the present invention is conducive to early leakage detection of storage tanks, and buys sufficient time for early intervention of enterprises, especially for the prevention of early leakage and overflow problems of underground storage tanks. At the same time, because the instantaneous flow of the flow meter is affected by the change of pipeline pressure and valve opening, the instantaneous value of the flow has a certain fluctuation. The present application adopts the method of equivalent instantaneous flow rate and equivalent volume dynamic change rate to jointly judge, overcome the interference caused by instantaneous flow fluctuations, so that the measurement scheme can judge the occurrence of leakage or overflow without increasing additional investment, and can also judge whether there is a fault in the liquid level meter.
[0034] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application. The scope of the present application is defined by the appended claims and their equivalents, and all shall be included in the scope of protection of the present application.
Claims
1. A tank overflow and leakage detection system, characterized in that: include: A liquid level detection module, used to obtain the liquid level heights of at least two positions of each storage tank of the storage tank group, and determine the volume of the liquid in the storage tank according to the liquid level heights; A flow detection module is used to obtain the dynamic instantaneous flow of the output pipe and input pipe of the storage tank group; The diagnostic module is used to judge the leakage / overflow of the tank according to the cumulative flow of the liquid in a time period and the change in the volume of the liquid in the tank during the time period, or to judge the leakage / overflow of the tank according to the dynamic change rate of the equivalent volume of the liquid in the tank and the equivalent instantaneous flow.
2. The tank overflow and leakage detection system according to claim 1, characterized in that: It also includes an interlocking cut-off module and a cut-off valve group arranged at the inlet and outlet of the storage tank. The interlocking cut-off module is used to control the opening and closing of the cut-off valve group according to the leakage / overflow situation of the storage tank determined by the diagnosis module, and send out a corresponding alarm signal.
3. The tank overflow and leakage detection system according to claim 1, characterized in that: The flow detection module includes an inlet and outlet flow meter and a flow data processing module. The flow data processing module is used to calculate the cumulative flow and equivalent instantaneous flow of the liquid within a time period according to the dynamic instantaneous flow of the flow meter, and feed the result back to the diagnosis module.
4. The tank overflow and leakage detection system according to claim 1, characterized in that: The liquid level detection module includes at least two liquid level meters and a liquid level data processing module. The liquid level data processing module is used to calculate the volume change and equivalent volume dynamic change rate of the liquid in the storage tank within a time period according to the liquid level height detected by the liquid level meter, and feed the results back to the diagnosis module.
5. A method for detecting overflow and leakage of a storage tank, characterized in that: The steps are as follows: The liquid level detection module is used to obtain the liquid level height at different positions of each storage tank in the storage tank group, and the volume of the liquid in the storage tank is determined according to the liquid level height; The dynamic instantaneous flow of the output pipe and input pipe of the storage tank group is obtained through the flow detection module; The diagnostic module determines the leakage / overflow of the tank based on the cumulative flow of the liquid in a time period and the change in the volume of the liquid in the tank during the time period, or determines the leakage / overflow of the tank based on the dynamic change rate of the equivalent volume of the liquid in the tank and the equivalent instantaneous flow.