Method and system for desorption and condensation treatment of organic waste gas

Abstract

The application relates to the technical field of flow control, in particular to an organic waste gas desorption condensation treatment method and system, which comprises the following steps: acquiring internal temperature sequences and external temperature sequences of condensation equipment in a condensation state and condensation equipment in a condensation regeneration state at each moment, respectively; acquiring a condensation completion moment after each condensation is completed and a regeneration completion moment after each condensation regeneration is completed; determining relative condensation efficiencies, relative internal-external temperature differences and temperature gradient characteristics at each moment; determining condensation progress at any historical condensation moment and regeneration progress at any historical regeneration moment; determining real-time regeneration progress, real-time condensation progress and condensation progress errors at the current moment; and controlling the heat medium flow in combination with a PID algorithm. The application realizes real-time regulation and control of the heat medium flow, so that the condensation process and the condensation capacity regeneration process are synchronously performed, thereby reducing the overall energy consumption of the condensation equipment and being beneficial to delaying equipment aging.

Description

Technical Field

[0001] This application relates to the field of flow control technology, specifically to a method and system for desorption and condensation treatment of organic waste gas. Background Technology

[0002] Because the condensation demand for organic waste gas is continuous, some organic matter in the waste gas easily condenses on the condensation pipes, thus affecting the condensation capacity of the condensation equipment. Therefore, the condensation device needs to periodically liquefy, separate, and collect the condensed organic matter on the pipes to ensure the normal operation of the condensation equipment. When treating organic waste gas with condensation, two sets of condensation equipment are usually arranged and used alternately. While one set of condensation equipment is condensing the organic waste gas, the other set is liquefying the attached organic matter, thereby regenerating the condensation capacity of the condensation equipment.

[0003] For the regeneration of condensing capacity in condensing equipment, traditional methods typically involve introducing a heat transfer medium into the condensing pipes to liquefy the attached organic matter, thereby enabling the condensing equipment to quickly restore its condensing capacity. This traditional method uses a heat transfer medium with a fixed flow rate, fixed time duration, and fixed temperature for liquefaction. However, excessive heat transfer medium flow can cause significant deformation of the condensing equipment in a short period, accelerating its aging and leading to overheating and increased energy consumption. Therefore, in the process of desorption and condensation treatment of organic waste gas, there are problems of increased energy consumption and equipment aging due to improper control of the heat transfer medium flow signal. Summary of the Invention

[0004] To address the aforementioned technical problems, a method and system for desorption and condensation treatment of organic waste gas are provided to solve the existing issues.

[0005] The solution to the technical problem addressed in this application is to provide a method and system for desorption and condensation treatment of organic waste gas, comprising the following steps:

[0006] In a first aspect, embodiments of this application provide a method for desorption and condensation treatment of organic waste gas, the method comprising the following steps:

[0007] Obtain the internal and external temperature sequences of the condensing equipment in the condensation state at each time, as well as the internal and external temperature sequences of the condensing equipment in the condensation regeneration state at each time; obtain the condensation completion time after each condensation is completed and the regeneration completion time after each condensation regeneration is completed.

[0008] Based on the differences between the internal and external temperature sequences of the condensing equipment in the condensation state at each moment, the relative condensation efficiency at each moment is determined; the differences between the internal and external temperature sequences of the condensing equipment in the condensation regeneration state at each moment are analyzed to obtain the relative internal and external temperature difference at each moment; based on the rate of change of the internal and external temperature difference of the condensing equipment in the condensation regeneration state between each moment and the adjacent moment and the degree of its distribution shift, the temperature gradient characteristics at each moment are calculated.

[0009] All moments during multiple condensation processes and multiple condensation and regeneration processes of the condensing equipment before the current moment are recorded as each historical condensation moment and each historical regeneration moment, respectively. Based on any historical condensation moment and the condensation completion moment, and any historical regeneration moment and the regeneration completion moment, the condensation progress of any historical condensation moment and the regeneration progress of any historical regeneration moment are determined, respectively.

[0010] Based on the differences in the relative internal and external temperature differences and the temperature gradient characteristics between the current moment and all its historical regeneration moments, and in conjunction with the regeneration progress, the real-time regeneration progress at the current moment is determined.

[0011] Based on the difference in relative condensation efficiency between the current moment and all its historical condensation moments, and in conjunction with the condensation progress, the real-time condensation progress at the current moment is determined.

[0012] Based on the real-time regeneration progress and the real-time condensation progress, the condensation progress error at the current moment is determined. Combined with the PID algorithm, the flow rate of the heat medium in the condensing equipment that is in the condensation regeneration state at the current moment is controlled.

[0013] Preferably, determining the relative condensation efficiency at each time point includes:

[0014] The difference between the internal temperature sequence and the external temperature sequence of the condensing equipment at each moment in the condensing state is formed into a condensing temperature difference sequence; the mean of all elements in the condensing temperature difference sequence is recorded as the heat exchange temperature difference.

[0015] The ratio of the heat exchange temperature difference at each moment to the preset temperature difference threshold is used as the relative condensation efficiency at each moment.

[0016] Preferably, obtaining the relative internal and external temperature difference at each moment includes:

[0017] Based on the control input of the condensing system, the heat medium temperature and the refrigerant temperature input to the condensing system are obtained; the difference between the heat medium temperature and the refrigerant temperature is recorded as the maximum temperature difference;

[0018] The difference between the internal temperature sequence and the external temperature sequence in the condensing equipment at each moment in the condensing regeneration state is formed into a regeneration temperature difference sequence; the mean of all elements in the regeneration temperature difference sequence is recorded as the condensing regeneration temperature difference.

[0019] The ratio of the condensation regeneration temperature difference at each moment to the maximum temperature difference is taken as the relative internal and external temperature difference at each moment.

[0020] Preferably, the method for calculating the temperature gradient characteristics at each time point is as follows:

[0021] The differences between the regeneration temperature difference sequence at each time point and the previous time point are used to form a temperature difference velocity sequence;

[0022] The skewness of the temperature difference velocity sequence is calculated as the temperature gradient feature at each time point. If the skewness is less than a preset first value, the temperature gradient feature is assigned the preset first value. If the skewness is greater than a preset second value, the temperature gradient feature is assigned the preset second value. The preset first value is less than the preset second value.

[0023] Preferably, determining the condensation progress at any historical condensation moment and the regeneration progress at any historical regeneration moment includes:

[0024] The time interval between any historical condensation moment and the condensation completion moment during each condensation process is taken as the condensation progress at any historical condensation moment.

[0025] The time interval between any historical regeneration moment and the regeneration completion moment during each condensation regeneration process is taken as the regeneration progress at any historical regeneration moment.

[0026] Preferably, determining the real-time regeneration progress at the current moment includes:

[0027] The relative internal and external temperature difference of the condensing equipment currently in the condensation regeneration state is used as the temperature feature weight at the current moment;

[0028] The method for calculating the similarity of temperature characteristics between the current time and any of the historical regeneration times is as follows: Among them, DT t→g γ represents the similarity of temperature characteristics between the current time t and the g-th historical regeneration time. t γ represents the relative internal and external temperature difference of a condensing device in condensation regeneration at the current time t. g Let δ be the relative internal and external temperature difference at the g-th historical regeneration moment. t δ represents the temperature gradient characteristics of a condensing device in condensation regeneration mode at the current time t. gFor the temperature gradient characteristics at the g-th historical regeneration time, ε t The temperature characteristic weight of the condensing equipment in the condensation regeneration state at the current time t, where τ is a preset value greater than 0;

[0029] The temperature characteristics similarity between the current moment and all historical regeneration moments are normalized, and the regeneration progress of all historical regeneration moments is weighted and summed with the normalization result to obtain the real-time regeneration progress of the current moment.

[0030] Preferably, the real-time condensation progress Fr at the current time t t The calculation method is as follows: Among them, F s Let β be the condensation progress at the s-th historical condensation moment. s Let β be the relative condensation efficiency at the s-th historical condensation moment. t S represents the relative condensation efficiency at the current time t. t This represents the number of all historical condensation times corresponding to the current time t, where ∈ is a preset value greater than 0.

[0031] Preferably, the condensation progress error J at the current time t t The calculation method for J is as follows: t =Dr t -(Fr t +M), where Dr t Fr represents the real-time regeneration progress at the current time t. t M represents the real-time condensation progress at the current time t, and M is the preset redundancy time.

[0032] Preferably, controlling the flow rate of the heat transfer medium in the condensing equipment currently in the condensation regeneration state includes:

[0033] The condensation progress error is used as the input of the PID algorithm, and the output is a flow control signal for the heat medium flow rate. The condensation system adjusts and controls the heat medium flow rate in the condensation equipment that is currently in the condensation regeneration state according to the flow control signal.

[0034] Secondly, embodiments of this application also provide an organic waste gas desorption and condensation treatment system, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any of the above-described organic waste gas desorption and condensation treatment methods.

[0035] This application has at least the following beneficial effects:

[0036] This application determines the relative condensation efficiency at each moment based on the difference between the internal and external temperature sequences of the condensing equipment in the condensation state. Its advantage lies in considering the condensation capacity of the condensing equipment in the condensation state at that moment, reflecting the state of organic matter attachment in the corresponding condensing equipment. It analyzes the difference between the internal and external temperature sequences of the condensing equipment in the condensation regeneration state at each moment to obtain the relative internal and external temperature difference at each moment. Based on the rate of change of the internal and external temperature difference and the degree of distribution shift of the condensing equipment in the condensation regeneration state between each moment and adjacent moments, it calculates the temperature gradient characteristics at each moment. Its advantage lies in considering the shedding of organic matter attachments in the condensing equipment in the condensation regeneration state, reflecting the progress of condensation regeneration by observing the layered shedding of organic matter from top to bottom. Based on any historical regeneration moment and the regeneration completion moment, it determines the regeneration progress at any historical regeneration moment. Based on the differences in the relative internal and external temperature difference and the temperature gradient characteristics between the current moment and all historical regeneration moments, combined with the regeneration progress, it determines the real-time regeneration progress at the current moment. Its advantage lies in considering the differences between the condensing equipment in the condensation regeneration state at the current moment and the historical condensation regeneration process. The method considers the proximity of organic matter shedding between historical regeneration moments to reflect how long it will take for the condensing equipment currently in the condensation regeneration state to complete its condensation capacity regeneration. Based on any historical condensation moment and the condensation completion moment, the condensation progress at any historical condensation moment is determined. According to the difference in relative condensation efficiency between the current moment and all historical condensation moments, combined with the condensation progress, the real-time condensation progress at the current moment is determined. This method considers the proximity of the relative condensation efficiency between the current moment and historical condensation moments in the historical condensation process, reflecting how long the condensing equipment can maintain its condensation state. Based on the real-time regeneration progress and the real-time condensation progress, the condensation progress error at the current moment is determined. Combined with a PID algorithm, the heat transfer fluid flow rate in the condensing equipment currently in the condensation regeneration state is controlled. This method considers the difference between the real-time condensation progress and the real-time regeneration progress, reflecting the asynchrony between the condensation process and the condensation capacity regeneration process. By using the PID algorithm to regulate the heat transfer fluid flow rate in real time, the condensation process and the condensation capacity regeneration process are synchronized, thereby reducing the overall energy consumption of the condensing equipment and helping to delay equipment aging. Attached Figure Description

[0037] The following description, in conjunction with the accompanying drawings, provides a further detailed explanation of an organic waste gas desorption and condensation treatment method of this application.

[0038] Figure 1 A flowchart illustrating the steps of an organic waste gas desorption and condensation treatment method provided in this application embodiment;

[0039] Figure 2 This is a schematic diagram of the installation of a temperature sensor in a condensing device provided in an embodiment of this application;

[0040] Figure 3 A flowchart illustrating the steps of a method for obtaining the relative internal and external temperature difference of a condensing device in a condensation regeneration state at various times, as provided in an embodiment of this application.

[0041] Figure 4 A flowchart illustrating the method for obtaining condensation progress error provided in an embodiment of this application. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description of an organic waste gas desorption and condensation treatment method and system proposed in this application, in conjunction with the accompanying drawings and embodiments, is provided. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0044] Please see Figure 1 The diagram illustrates a flowchart of an organic waste gas desorption and condensation treatment method according to an embodiment of this application. The method includes the following steps:

[0045] Step 1: Obtain the internal and external temperature sequences of the condensing equipment in the condensing state at each time, as well as the internal and external temperature sequences of the condensing equipment in the condensing regeneration state at each time; obtain the condensing completion time after each condensing is completed and the regeneration completion time after each condensing regeneration is completed.

[0046] In the organic waste gas treatment process, the organic waste gas mainly consists of externally transported organic waste gas and desorption waste gas generated by the adsorption tower. The organic waste gas contains organic compounds such as styrene, vinyl acetate, and butyl acrylate. The waste gas is sent to the tail gas skid buffer tank through pipelines. The pipelines are equipped with components such as flame arresters, thermometers, pressure gauges, and flow meters to monitor the safety of the pipelines. The buffer tank is equipped with a pressure alarm indicator to monitor the internal pressure of the buffer tank.

[0047] The buffer tank is connected to a blower, which pressurizes the gas inside the buffer tank. When the pressure alarm indicator inside the buffer tank detects that the gas pressure inside the buffer tank reaches 20 kPa, the valve on the pipeline connecting the blower and the condensation system is opened, allowing the organic waste gas inside the buffer tank to be sent into the condensation system.

[0048] The organic waste gas sent into the condensation system first enters the precooler, where it is precooled by the -40℃ purified gas. The purified gas is returned from the output pipe of the subsequent condenser, realizing the reuse of the condenser's refrigeration resources. After precooling, the organic waste gas is input into the condensation equipment for further condensation.

[0049] After pre-cooling, the organic waste gas enters the condenser. A -50°C refrigerant is then introduced into the condensation equipment to exchange heat with the waste gas, bringing it to -40°C. This condenses the organic matter in the waste gas, leaving it in the condensation system. In this embodiment, two sets of condensation equipment, A and B, are used alternately. The alternation method is as follows:

[0050] Condensing device A first enters the condensation state to condense the organic waste gas. During the condensation process, the condensation efficiency of condensing device A is judged in real time. When the condensation efficiency of condensing device A drops to a preset threshold, organic matter adhesion occurs in condensing device A, causing the condensation efficiency to decrease. At this time, heat medium is introduced into condensing device A to heat and liquefy the organic matter attached to the condensation pipe to remove the organic matter, so that condensing device A enters the condensation capacity regeneration state. At the same time, condensing device B takes over the condensation state from condensing device A.

[0051] The condensation state refers to the state of condensing organic waste gas. In this state, the condensing equipment is responsible for condensing the organic matter in the waste gas. The condensation regeneration state refers to the state of restoring the condensing capacity of a condensing equipment with low condensation efficiency. In this state, the condensing equipment is responsible for heating and liquefying the organic matter attached to the condensing pipes to remove the organic matter attached to the pipe surface and complete the regeneration of condensation capacity. When one of the condensing equipment is found to have organic matter attachment, resulting in a decrease in condensation efficiency, the two condensing equipment exchange their working states, completing the alternating use of the condensing equipment. The working states are the condensation state and the condensation regeneration state.

[0052] After the organic waste gas is condensed by condenser A or condenser B, most of the organic matter in the high-concentration organic waste gas is condensed. The condensate from the condensation process flows by gravity to the condensate tank for storage. The gas purified by the condensation equipment is then fed into the adsorption tower to further reduce the concentration of organic waste gas in the gas. During the adsorption process in the adsorption tower, after the adsorbent adsorbs the organic matter in the organic waste gas, it needs to be desorbed. Desorption waste gas is generated during the desorption process. The desorbed waste gas is transported to the buffer tank and condensed with the organic waste gas transported from the outside, thereby realizing circulation and ensuring that the waste gas is completely treated.

[0053] In the above-mentioned organic waste gas treatment process, two condensation devices need to be controlled. When one condensation device enters the regeneration state, the flow control signal of the device needs to be controlled. If the flow control signal is too large, the flow rate of the heat medium input into the condensation device will be too large, which will lead to increased expansion and wear of the condensation device and accelerate its aging. Therefore, in order to improve the service life of the equipment, the organic deposits should be removed slowly by making full use of the allowable time according to the relative time when the two condensation devices are about to switch working states, and the flow rate of the condensation device should be controlled.

[0054] Based on the above analysis, at a certain moment, when condensing equipment A is condensing, condensing equipment B is simultaneously regenerating its condensing capacity. It is necessary to assess the condensing state of condensing equipment A and then dynamically adjust the flow control signal of the heat transfer medium in condensing equipment B to synchronize the regeneration process of condensing equipment B with the condensing process of condensing equipment A. This reduces the heat transfer medium flow rate of condensing equipment B and slows down the aging of the condensing equipment. Therefore, it is necessary to assess the adhesion of organic matter to the condensing equipment during the condensation process and the removal of organic matter during the condensation regeneration process.

[0055] This embodiment uses a fixed tube sheet heat exchanger as the condensing device. Temperature sensors are placed at a certain distance from the heat exchange pipes within the space containing the organic waste gas of the condensing device. Simultaneously, temperature sensors are also placed at the same horizontal position within the heat exchange pipes. The installation diagram of the temperature sensors in the condensing device in this embodiment is shown below. Figure 2 As shown.

[0056] exist Figure 2 In the diagram, C1 is the organic waste gas inlet, C2 is the purified gas outlet, C3 is the condensate outlet, C4 is the refrigerant or heat medium inlet, and C5 is the refrigerant or heat medium outlet. The white area of ​​D1 is the flow area of ​​the organic waste gas, the gray area of ​​D2 is the flow area of ​​the refrigerant or heat medium (i.e., the heat exchange pipe), the black area of ​​D3 is the baffle of the fixed tube sheet heat exchanger, and the intersection of D4 represents the temperature sensor. A temperature sensor is installed inside the heat exchange pipe D2, and another temperature sensor is installed at the same height outside the pipe. The spacing between two adjacent temperature sensors inside the heat exchange pipe D2 is the same.

[0057] The temperatures of all temperature sensors inside the heat exchange pipes of the condensing equipment at each moment, and the temperatures of all temperature sensors outside the heat exchange pipes, are arranged in order from top to bottom according to the installation position of the temperature sensors, to form the internal temperature sequence and external temperature sequence of the condensing equipment at each moment.

[0058] The temperatures of all temperature sensors inside the heat exchange pipes and all temperature sensors outside the heat exchange pipes in the condensing equipment that are in the condensing regeneration state at each time are arranged in order from top to bottom according to the installation position of the temperature sensors, forming the internal temperature sequence and external temperature sequence of the condensing equipment in the condensing regeneration state at each time.

[0059] Obtain the condensation completion time after each condensation is completed, and the regeneration completion time after each condensation and regeneration is completed;

[0060] Preferably, in this embodiment, the temperature sensor collects temperature data every 10 seconds and records the collected data in the log module of the condensation system. As for other implementation methods, the implementer can set it according to the actual situation.

[0061] It should be noted that in this embodiment, it is assumed that at a certain moment, condensing device A is in a condensing state and condensing device B is in a condensing regeneration state; secondly, the internal temperature sequence and the external temperature sequence at the same dimension represent the temperatures monitored by two temperature sensors at the same horizontal level inside and outside the heat exchange pipe.

[0062] Thus, the internal and external temperature sequences corresponding to the condensing equipment in the condensing state at each time are obtained, as well as the internal and external temperature sequences corresponding to the condensing equipment in the condensing regeneration state at each time; the condensing completion time after each condensing is completed and the regeneration completion time after each condensing regeneration are obtained.

[0063] Step 2: Based on the differences between the internal and external temperature sequences of the condensing equipment in the condensation state at each time point, determine the relative condensation efficiency at each time point; analyze the differences between the internal and external temperature sequences of the condensing equipment in the condensation regeneration state at each time point to obtain the relative internal and external temperature difference at each time point; calculate the temperature gradient characteristics at each time point based on the rate of change of the internal and external temperature difference and the degree of distribution shift of the condensing equipment in the condensation regeneration state between each time point and adjacent time points.

[0064] Furthermore, based on the internal and external temperature sequences, the temperature difference inside and outside the heat exchange pipe is analyzed to reflect the adhesion of organic matter in the condensing equipment A under condensation conditions. Specifically:

[0065] The differences between elements at the same position in the internal temperature sequence and the external temperature sequence of the condensing device at each moment when it is in a condensing state are formed into a condensing temperature difference sequence; the mean value of all elements in the condensing temperature difference sequence is recorded as the heat exchange temperature difference.

[0066] Preferably, in this embodiment, the absolute values ​​of the differences between elements at the same position in the condensing device that is in a condensing state at each time are used to form a condensing temperature difference sequence. It should be noted that, for ease of understanding, it is assumed that the internal temperature sequence is [IT1,IT2,IT3,IT4], the external temperature sequence is [OT1,OT2,OT3,OT4], and the condensing temperature difference sequence is [|IT1-OT1|,|IT2-OT2|,|IT3-OT3|,|IT4-OT4|.

[0067] It should be noted that the greater the heat exchange temperature difference, the more severe the organic matter adhesion on the heat exchange pipes of the condensing equipment A, which is in a condensing state, and the more it affects the condensation of organic waste gas.

[0068] The ratio of the heat exchange temperature difference to the preset temperature difference threshold is used as the relative condensation efficiency at each time point.

[0069] Preferably, in this embodiment, the preset temperature difference threshold is set to 10°C. In other implementation methods, the implementer can set it according to the actual situation.

[0070] It should be noted that when the relative condensation efficiency rises to 1, it indicates that the organic matter in the condensing equipment A, which is in a condensing state, is severely attached, and the condensing capacity of the condensing equipment A needs to be regenerated. The larger the heat exchange temperature difference, the worse the temperature exchange efficiency inside and outside the heat exchange pipe, which is why a temperature difference is formed. When the heat exchange temperature difference exceeds the preset temperature difference threshold, it indicates that there is too much organic matter attached to the surface of the heat exchange pipe, which has greatly hindered heat exchange, and the condensing capacity needs to be regenerated.

[0071] Based on the above analysis, the relative condensation efficiency can be used to determine the organic matter adhesion status of condensing equipment A in the condensation state. Secondly, it is necessary to evaluate the regeneration progress of condensing equipment B in the condensation regeneration state to ensure that the condensation capacity regeneration process of condensing equipment B in the condensation regeneration state is synchronized with the condensation process of condensing equipment A in the condensation state, thereby reducing the heat medium flow of condensing equipment B and slowing down equipment aging.

[0072] For condensing equipment B in the condensation regeneration state, organic matter removal is achieved by injecting a heat transfer medium into the fixed plate heat exchanger. The faster the heat transfer medium is injected, the greater the removal effect on the organic matter in condensing equipment B. As the condensation capacity regeneration process proceeds, the organic matter detaches, and the temperature difference monitored by two temperature sensors at the same height on the fixed plate heat exchanger gradually decreases. Therefore, the regeneration progress of condensing equipment B in the condensation regeneration state can be evaluated using the internal temperature sequence and the external temperature sequence.

[0073] The condensation regeneration process of condensing equipment B can be roughly divided into two stages. The first stage is the overall heating stage, in which the organic deposits on the heat exchange pipes are heated by the heat medium, and the temperature sensor can detect that the temperature difference between the inside and outside of the heat exchange pipes gradually decreases. As the organic deposits are affected by heating, they gradually melt and fall off; this stage is called the deposit liquefaction stage. Since the liquefaction and fall off of the upper layer of deposits will affect the liquefaction and fall off of the lower layer of deposits, the temperature difference between the sensors inside and outside the upper layer of the heat exchange pipes will decrease faster in this process, resulting in faster regeneration of the upper layer and slower regeneration of the lower layer. Based on this analysis, the temperature difference monitored by the temperature sensor at the same height at each moment is analyzed to determine the relative internal and external temperature difference, reflecting the stage that condensing equipment B is in during the condensation regeneration process, and thus explaining the regeneration progress of condensing equipment B. The flowchart of the method for obtaining the relative internal and external temperature difference of the condensing equipment in the condensation regeneration state at each moment provided in the embodiments of this application is shown below. Figure 3 As shown, it specifically includes:

[0074] Based on the control input in the condensing system, the heat medium temperature and refrigerant temperature input to the condensing system are obtained;

[0075] It should be noted that the heat medium temperature and the cold medium temperature are the temperatures of the heat medium and the cold medium before they enter the heat exchange pipeline, respectively. These temperatures are controlled by an external energy storage device, and the heat medium temperature and the cold medium temperature are constant values.

[0076] The difference between the temperature of the heat medium and the temperature of the refrigerant is recorded as the maximum temperature difference;

[0077] The difference between the internal temperature sequence and the external temperature sequence in the condensing equipment that is in the condensing regeneration state at each moment is formed into a regeneration temperature difference sequence.

[0078] The mean value of all elements in the regeneration temperature difference sequence is denoted as the condensation regeneration temperature difference.

[0079] Preferably, in this embodiment, the absolute values ​​of the differences between the internal temperature sequence and the external temperature sequence in the condensing device at each moment in the condensing regeneration state are used to form the regeneration temperature difference sequence.

[0080] The ratio of the condensation regeneration temperature difference at each moment to the maximum temperature difference is taken as the relative internal and external temperature difference of the condensation equipment in the condensation regeneration state at each moment.

[0081] It should be noted that the smaller the relative internal and external temperature difference, the lower the heating temperature of the organic deposits in the condensing equipment B, which is in the condensation regeneration state, the higher the degree of organic deposit shedding, and the higher the completion rate of the condensing capacity regeneration progress of the condensing equipment B.

[0082] Furthermore, during the overall heating stage of the condensation regeneration process of condensing equipment B, the temperature difference between the inside and outside of the heat exchange pipes is large, and the temperature difference distribution from top to bottom is relatively uniform. Therefore, at this stage, the temperature difference between the inside and outside of the heat exchange pipes can well reflect the recovery progress of condensation regeneration. However, during the liquefaction stage of the deposits, the temperature difference between the inside and outside of the heat exchange pipes gradually decreases. Moreover, since the organic deposits detached from the upper layer will hinder the detachment of the organic deposits from the lower layer, the temperature difference between the inside and outside of the heat exchange pipes in condensing equipment B is small, and the temperature difference distribution between the upper and lower layers is uneven. At this time, reflecting the detachment of organic deposits in condensing equipment B by the relative internal and external temperature difference will have a large error. Therefore, it is necessary to further analyze the condensation regeneration progress of condensing equipment B by combining the rate of temperature change inside and outside the heat exchange pipes.

[0083] Because the upper layer of organic deposits detaches faster than the lower layer, the temperature change rate inside and outside the upper heat exchange pipe is initially faster than that of the lower layer. As the upper organic deposits completely detach, the rate of temperature change inside and outside the upper pipe gradually approaches zero, and the pipes with faster temperature changes gradually move downwards. The progress of organic deposit detachment during the liquefaction stage is determined by the positional distribution of the rate of temperature change inside and outside the heat exchange pipe along the pipe.

[0084] The differences between the regeneration temperature difference sequence at each time point and the previous time point are used to form a temperature difference velocity sequence;

[0085] It should be noted that the obtained temperature difference velocity sequence reflects the stratification and shedding characteristics of organic deposits on the heat exchange pipes during the condensation capacity regeneration process of condensing equipment B. The larger the h-th element in the temperature difference velocity sequence, the faster the organic deposits at the location of the h-th temperature sensor shed.

[0086] The skewness of the temperature difference velocity sequence is calculated as the temperature gradient feature of the condensing equipment in the condensation regeneration state at each moment. If the skewness is less than a preset first value, the temperature gradient feature is assigned the preset first value. If the skewness is greater than a preset second value, the temperature gradient feature is assigned the preset second value. The preset first value is less than the preset second value.

[0087] It should be noted that the first preset value is -1 and the second preset value is 1. As other implementation methods, the implementer can set them according to the actual situation. Since the value range of the skewness is (-∞, +∞), if the skewness is less than -1, the temperature gradient feature is assigned a value of -1. If the skewness is greater than 1, the temperature gradient feature is assigned a value of 1. If the skewness is greater than -1 and less than 1, the temperature gradient feature is the corresponding skewness. Therefore, the value range of the temperature gradient feature is [-1, 1].

[0088] It should be noted that the smaller the temperature gradient feature, the larger the element value on the left side of the temperature difference velocity sequence is compared to the element value on the right side, indicating that the organic deposits on the upper layer of the heat exchange pipe are detached faster, and that the condensing device B is more likely to be in the initial stage of the deposit liquefaction stage. Conversely, the larger the temperature gradient feature, the larger the element value on the right side of the temperature difference velocity sequence is compared to the element value on the left side, indicating that the organic deposits on the lower layer of the heat exchange pipe surface are detached faster, and that the condensing device B is more likely to be in the final stage of the deposit liquefaction stage.

[0089] Thus, the relative condensation efficiency of the condensing equipment in the condensation state at each moment, as well as the relative internal and external temperature difference and temperature gradient characteristics of the condensing equipment in the condensation regeneration state at each moment, are obtained.

[0090] Step 3: Based on any historical regeneration time and the regeneration completion time, determine the regeneration progress of any historical regeneration time; based on the differences in the relative internal and external temperature difference and the temperature gradient characteristics between the current time and all historical regeneration times, and in conjunction with the regeneration progress, determine the real-time regeneration progress at the current time.

[0091] Based on the above analysis, the larger the relative internal and external temperature difference, the more likely the heat exchanger is in the overall heating stage; the smaller the relative internal and external temperature difference, the more likely the heat exchanger is in the deposit liquefaction stage. Therefore, by judging the condensation capacity regeneration stage of the heat exchanger by the temperature difference between the inside and outside of the heat exchange pipe, the temperature characteristic weight is determined to reflect whether the condensing equipment B is in the overall heating stage or the deposit liquefaction stage.

[0092] Record all moments during the multiple condensation and regeneration processes of the condensing equipment up to the current moment as each historical regeneration moment;

[0093] Preferably, in this embodiment, all moments during the 10 condensation regeneration processes of the condensation device before the current moment are recorded as historical regeneration moments. As for other implementation methods, the implementer can set them according to the actual situation.

[0094] It should be noted that, assuming a condensation regeneration process takes time T1 from start to finish, and since the temperature is sampled every 10 seconds, there are [temperature variations] during this condensation regeneration process. The process involves several steps: First, if the total number of condensing capacity regeneration processes performed before the current time is greater than or equal to 1 but less than 10, then all times during all condensing capacity regeneration processes are obtained and recorded as historical regeneration times. Second, if the total number of condensing capacity regeneration processes performed before the current time is less than 1, it indicates that the condensing system is in the initialization stage, and this condensing capacity regeneration process is manually controlled by technicians, and the flow signal control method described in this embodiment is not applicable.

[0095] Based on the internal and external temperature sequences of the condensation equipment at any historical regeneration moment during each condensation and regeneration process, the relative internal and external temperature difference and temperature gradient characteristics at any historical regeneration moment are calculated.

[0096] The time interval between any historical regeneration moment and the regeneration completion moment during each condensation regeneration process is recorded as the regeneration progress at any historical regeneration moment.

[0097] Furthermore, based on the differences between the relative internal and external temperature differences and temperature gradient characteristics corresponding to the current time and the historical regeneration time, the similarity of temperature characteristics is determined, specifically as follows:

[0098] The relative internal and external temperature difference of the condensing equipment currently in the condensation regeneration state is used as the temperature feature weight at the current moment;

[0099] The method for calculating the similarity of temperature characteristics between the current time and any of the historical regeneration times is as follows: Among them, DT t→g γ represents the similarity of temperature characteristics between the current time t and the g-th historical regeneration time. t γ represents the relative internal and external temperature difference of a condensing device in condensation regeneration at the current time t. g Let δ be the relative internal and external temperature difference at the g-th historical regeneration moment. t δ represents the temperature gradient characteristics of a condensing device in condensation regeneration mode at the current time t. g For the temperature gradient characteristics at the g-th historical regeneration time, ε t The temperature characteristic weight of the condensing equipment in the condensation regeneration state at the current time t is τ, which is a preset value greater than 0 to avoid the denominator being 0. The value range of τ is (0, 1]. In this embodiment, the value of τ is 0.1. As for other implementation methods, the implementer can set it according to the actual situation.

[0100] It should be noted that the temperature feature similarity DT t→g The larger the value, the smaller the difference between the temperature characteristics at the corresponding g-th historical regeneration moment and the current moment t, reflecting that the condensation regeneration progress of the condensation equipment in the condensation regeneration state at the current moment t is closer to the regeneration progress at the g-th historical regeneration moment.

[0101] The temperature characteristics similarity between the current moment and all historical regeneration moments are normalized, and the regeneration progress of all historical regeneration moments is weighted and summed with the normalization result to obtain the real-time regeneration progress of the current moment.

[0102] Preferably, in this embodiment, the normalization process is as follows: calculate the sum of the temperature feature similarities between the current time and all historical regeneration times, and use the ratio of the temperature feature similarities to the sum as the normalization result between the current time and any historical regeneration time.

[0103] It should be noted that the method for calculating the weighted sum is a well-known technique and will not be elaborated upon here.

[0104] It should be noted that the high similarity of temperature characteristics indicates that the smaller the difference between the heat exchanger temperature characteristics of the condensing equipment in the condensation regeneration state at the current time t and the historical condensation regeneration time, the larger the value with the normalized result as the weight. The real-time regeneration progress at the current time t is evaluated using the regeneration progress corresponding to the historical regeneration time with small temperature characteristic differences, and the regeneration progress of the condensing equipment B in the condensation regeneration state is estimated. Secondly, estimating the real-time regeneration progress at the current time t by using the temperature characteristics of historical times in the historical condensation regeneration process is beneficial to accurately judge the current condensing capacity regeneration status of the condensing equipment B, and is beneficial to dynamically adjust the flow control signal according to the condensing capacity regeneration status in the future, so as to avoid the equipment aging caused by excessive heat medium flow, or to avoid the condensing equipment B being unable to replace the condensing equipment A for condensation treatment in time due to insufficient heat medium flow.

[0105] At this point, the real-time regeneration progress is obtained.

[0106] Step 4: Based on any historical condensation time and the condensation completion time, determine the condensation progress of any historical condensation time; based on the difference in relative condensation efficiency between the current time and all historical condensation times, and in conjunction with the condensation progress, determine the real-time condensation progress at the current time.

[0107] Furthermore, the real-time regeneration progress reflects the recovery of the condensing capacity of the condensing equipment in the condensation regeneration state; based on the relative condensing efficiency of the condensing equipment at each moment in each condensation process before the current moment, the real-time condensation progress is determined to reflect the condensing capacity of the condensing equipment in the condensation state, specifically as follows:

[0108] Record all moments during the multiple condensation processes performed by the condensing equipment before the current moment as each historical condensation moment;

[0109] Preferably, in this embodiment, all moments during the 10 condensation processes performed by the condensing device before the current moment are recorded as each historical condensation moment.

[0110] It should be noted that, assuming a condensation process takes T2 seconds from start to finish, and since the temperature is sampled every 10 seconds, there are [temperature variations] during this condensation process. The system acquires historical condensation moments. Secondly, if the total number of condensation processes before the current moment is greater than or equal to 1 but less than 10, then all moments during all condensation processes are acquired and recorded as historical condensation moments. If the total number of condensation processes before the current moment is less than 1, it indicates that the condensation system is in the initialization phase, and this condensation process is manually controlled by technicians; therefore, the method described in this embodiment for controlling the flow signal is not applicable.

[0111] Based on the internal and external temperature sequences of the condensing equipment at any historical condensation moment during each condensation process, the relative condensation efficiency at that historical condensation moment is calculated.

[0112] The time interval between any historical condensation moment and the condensation completion moment during each condensation process is recorded as the condensation progress at any historical condensation moment.

[0113] Furthermore, based on the difference in relative condensation efficiency between the current moment and historical condensation moments, and in conjunction with the condensation progress, the real-time condensation progress is determined, specifically as follows:

[0114] The method for calculating the real-time condensation progress at the current moment is as follows: Among them, Fr t F represents the real-time condensation progress at the current time t. s Let β be the condensation progress at the s-th historical condensation moment. s Let β be the relative condensation efficiency at the s-th historical condensation moment. t S represents the relative condensation efficiency at the current time t. t τ represents the number of all historical condensation times corresponding to the current time t, ∈ is a preset value greater than 0 to avoid the denominator being 0, and the value range of τ is (0, 1]. In this embodiment, τ is 0.1. As for other implementation methods, the implementer can set it according to the actual situation. norm() is the normalization function.

[0115] Preferably, in this embodiment, the current time is compared with the s-th historical condensation time. Let this be denoted as the condensation difference; calculate the sum of the condensation differences between the current time and all historical condensation times, and use the ratio of the condensation difference to the sum as the normalized value between the current time and the s-th historical condensation time. The formula for calculating the normalized value is:

[0116] It should be noted that the smaller the difference in relative condensation efficiency between the current time t and the s-th historical condensation time, the better the normalized value. The larger the weight value, the more similar the condensing capacity of the condensing equipment at the current time t is to the condensing state at historical condensing times. In other words, the condensing progress of the condensing equipment at the current time t is closer to the condensing progress at the g-th historical condensing time. Estimating the real-time condensing progress at the current time t using the condensing progress of historical condensing times with small condensing differences is beneficial for accurately judging the condensing capacity of the condensing equipment A currently in the condensing state. This is also beneficial for comparing the condensing progress of condensing equipment A with the regeneration progress of condensing equipment B, and thus controlling the flow signal.

[0117] At this point, the real-time condensation progress is obtained.

[0118] Step 5: Based on the real-time regeneration progress and the real-time condensation progress, determine the condensation progress error at the current moment; and combine the PID algorithm to control the flow rate of the heat medium in the condensation equipment that is in the condensation regeneration state at the current moment.

[0119] Furthermore, based on the difference between the real-time regeneration progress and the real-time condensation progress, the difference in the working progress of the two condensing devices is evaluated to determine the condensation progress error, which reflects the degree of synchronization between the condensation progress of condensing device A and the regeneration progress of condensing device B. Specifically:

[0120] The calculation method for the condensation progress error at the current moment is: J t =Dr t -(Fr t +M), where J t Dr represents the condensation progress error at the current time t. t Fr represents the real-time regeneration progress at the current time t. t M represents the real-time condensation progress at the current time t, and M is the preset redundancy time.

[0121] Preferably, in this embodiment, the preset redundancy time is set to 10 minutes. As for other implementation methods, the implementer can set it according to the actual situation.

[0122] It should be noted that the difference between real-time regeneration progress and real-time condensation progress, Dr... t -Fr t This reflects the difference in working progress between condensing equipment B and condensing equipment A, where Dr t -Fr t A positive difference indicates that the real-time regeneration progress of condensing equipment B is faster than the real-time condensation progress of condensing equipment A. In this case, the heat transfer medium flow rate in condensing equipment B is too high and needs to be reduced; conversely, Dr... t -Fr tIf the difference is negative, the heat transfer medium flow rate in condenser B needs to be increased. Secondly, the purpose of the preset redundancy time is to ensure that the condensing capacity regeneration process of condenser B completes before the condensing process of condenser A, leaving sufficient redundancy time to prevent the condensing process of condenser A from suddenly accelerating due to changes in the system environment while condenser B has not completed its condensing capacity regeneration process, causing condenser A's condensing process to complete prematurely and preventing condenser B from replacing condenser A for condensing treatment. Simultaneously, it allows the condensing control system sufficient redundancy time for switching between the two condensing devices. The flowchart of the condensing progress error acquisition method provided in this embodiment is as follows: Figure 4 As shown.

[0123] Furthermore, based on the aforementioned condensation progress error, the heat transfer medium flow rate is controlled using a PID (Proportional Integral Derivative) algorithm, specifically as follows:

[0124] The condensation progress error is used as the input of the PID algorithm, and the output is a flow control signal for the heat medium flow rate. The condensation system controls the heat medium flow rate in the condensation equipment B, which is currently in the condensation regeneration state, according to the flow control signal, thereby reducing overall energy consumption and delaying equipment aging.

[0125] Preferably, in this embodiment, the proportional coefficient is 0.7, the integral coefficient is 0.05, and the derivative coefficient is 50 in the PID algorithm. As for other implementation methods, the implementer can set them according to the actual situation. Secondly, the PID algorithm is a well-known technology and will not be described in detail here.

[0126] Based on the same inventive concept as the above method, this application embodiment also provides an organic waste gas desorption and condensation treatment system, including a memory, a processor, and a computer program stored in the memory and running on the processor. When the processor executes the computer program, it implements the steps of any one of the above-described organic waste gas desorption and condensation treatment methods.

[0127] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0128] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application, without departing from the content of the technical solution of this application, shall fall within the protection scope of the technical solution of this application.

Claims

1. A method for desorption and condensation treatment of organic waste gas, characterized in that, The method includes the following steps: Temperature sensors are placed at the same level as the inside and outside of the heat exchange pipes within the space containing the organic waste gas of the condensing equipment. The internal and external temperature sequences of the condensing equipment in the condensing state at each moment, as well as the internal and external temperature sequences of the condensing equipment in the condensing regeneration state at each moment, are collected. The condensing completion time and the regeneration completion time after each condensing regeneration are obtained. Based on the differences between the internal and external temperature sequences of the condensing equipment in the condensation state at each moment, the relative condensation efficiency at each moment is determined; the differences between the internal and external temperature sequences of the condensing equipment in the condensation regeneration state at each moment are analyzed to obtain the relative internal and external temperature difference at each moment; based on the rate of change of the internal and external temperature difference of the condensing equipment in the condensation regeneration state between each moment and the adjacent moment and the degree of its distribution shift, the temperature gradient characteristics at each moment are calculated. All moments during multiple condensation processes and multiple condensation and regeneration processes of the condensing equipment before the current moment are recorded as each historical condensation moment and each historical regeneration moment, respectively. Based on any historical condensation moment and the condensation completion moment, and any historical regeneration moment and the regeneration completion moment, the condensation progress of any historical condensation moment and the regeneration progress of any historical regeneration moment are determined, respectively. Based on the differences in the relative internal and external temperature differences and the temperature gradient characteristics between the current moment and all its historical regeneration moments, and in conjunction with the regeneration progress, the real-time regeneration progress at the current moment is determined. Based on the difference in relative condensation efficiency between the current moment and all its historical condensation moments, and in conjunction with the condensation progress, the real-time condensation progress at the current moment is determined. Based on the real-time regeneration progress and the real-time condensation progress, the condensation progress error at the current moment is determined. Combined with the PID algorithm, the flow rate of the heat medium in the condensing equipment that is in the condensation regeneration state at the current moment is controlled.

2. The method for desorption and condensation treatment of organic waste gas as described in claim 1, characterized in that, Determining the relative condensation efficiency at each moment includes: The difference between the internal temperature sequence and the external temperature sequence of the condensing equipment at each moment in the condensing state is formed into a condensing temperature difference sequence; the mean of all elements in the condensing temperature difference sequence is recorded as the heat exchange temperature difference. The ratio of the heat exchange temperature difference at each moment to the preset temperature difference threshold is used as the relative condensation efficiency at each moment.

3. The method for desorption and condensation treatment of organic waste gas as described in claim 1, characterized in that, The method for obtaining the relative internal and external temperature differences at each moment includes: Based on the control input of the condensing system, the heat medium temperature and the refrigerant temperature input to the condensing system are obtained; the difference between the heat medium temperature and the refrigerant temperature is recorded as the maximum temperature difference; The difference between the internal temperature sequence and the external temperature sequence in the condensing equipment at each moment in the condensing regeneration state is formed into a regeneration temperature difference sequence; the mean of all elements in the regeneration temperature difference sequence is recorded as the condensing regeneration temperature difference. The ratio of the condensation regeneration temperature difference at each moment to the maximum temperature difference is taken as the relative internal and external temperature difference at each moment.

4. The method for desorption and condensation treatment of organic waste gas as described in claim 3, characterized in that, The method for calculating the temperature gradient characteristics at each time point is as follows: The differences between the regeneration temperature difference sequence at each time point and the previous time point are used to form a temperature difference velocity sequence; The skewness of the temperature difference velocity sequence is calculated as the temperature gradient feature at each time point. If the skewness is less than a preset first value, the temperature gradient feature is assigned the preset first value. If the skewness is greater than a preset second value, the temperature gradient feature is assigned the preset second value. The preset first value is less than the preset second value.

5. The method for desorption and condensation treatment of organic waste gas as described in claim 1, characterized in that, Determining the condensation progress at any historical condensation moment and the regeneration progress at any historical regeneration moment includes: The time interval between any historical condensation moment and the condensation completion moment during each condensation process is taken as the condensation progress at any historical condensation moment. The time interval between any historical regeneration moment and the regeneration completion moment during each condensation regeneration process is taken as the regeneration progress at any historical regeneration moment.

6. The method for desorption and condensation treatment of organic waste gas as described in claim 1, characterized in that, Determining the real-time regeneration progress at the current moment includes: The relative internal and external temperature difference of the condensing equipment currently in the condensation regeneration state is used as the temperature feature weight at the current moment; The method for calculating the similarity of temperature characteristics between the current time and any of the historical regeneration times is as follows: ,in, For the current moment With the Similarity of temperature characteristics at each historical regeneration moment For the condensing equipment currently in the condensation regeneration state... The relative temperature difference between inside and outside, For the first The relative internal and external temperature difference at a historical regeneration moment For the condensing equipment in the condensation regeneration state at the current moment Temperature gradient characteristics, For the first Temperature gradient characteristics at each historical regeneration moment For the condensing equipment in the condensation regeneration state at the current moment Temperature feature weights, The default value is greater than 0; The temperature characteristics similarity between the current moment and all historical regeneration moments are normalized, and the regeneration progress of all historical regeneration moments is weighted and summed with the normalization result to obtain the real-time regeneration progress of the current moment.

7. The method for desorption and condensation treatment of organic waste gas as described in claim 1, characterized in that, Current moment Real-time condensation progress The calculation method is as follows: ,in, For the first The condensation progress at each historical condensation moment. For the first Relative condensation efficiency at each historical condensation moment For the current moment The relative condensation efficiency, For the current moment The number of all corresponding historical condensation moments. The default value is greater than 0.

8. The method for desorption and condensation treatment of organic waste gas as described in claim 1, characterized in that, Current moment Condensation progress error The calculation method is as follows: ,in, For the current moment Real-time regeneration progress, For the current moment Real-time condensation progress, This is a preset redundancy time.

9. The method for desorption and condensation treatment of organic waste gas as described in claim 1, characterized in that, The control of the heat transfer medium flow rate in the condensing equipment currently in condensation regeneration state includes: The condensation progress error is used as the input of the PID algorithm, and the output is a flow control signal for the heat medium flow rate. The condensation system adjusts and controls the heat medium flow rate in the condensation equipment that is currently in the condensation regeneration state according to the flow control signal.

10. An organic waste gas desorption and condensation treatment system, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the organic waste gas desorption and condensation treatment method as described in any one of claims 1-9.

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