Heat exchange medium adjusting method, device and equipment and computer readable storage medium

Abstract

The embodiment of the invention provides a heat exchange medium adjusting method, device and equipment and a computer readable storage medium. The method comprises the following steps: acquiring a fitting curve between the residence time of a reactor and the optimal inlet temperature of the reactor; determining the current optimal reactor inlet temperature according to the fitted curve; calculating a target enthalpy value of the heat exchanger according to the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger connected with the reactor; calculating the actual enthalpy value of the heat exchanger according to the inlet and outlet measured temperature of the heat exchanger; and according to the target enthalpy value and the actual enthalpy value, the flow of a heat exchange medium of the heat exchanger is adjusted. In this way, it can be ensured that the reactor inlet temperature can be optimized again to be close to or equal to the current optimal reactor inlet temperature through adjustment of the heat exchange medium flow no matter whether the reactor inlet temperature fluctuates and adiabatic temperature rise changes are caused by adjustment of the production load or changes of the material proportion; further, the conversion rate and selectivity of the reactor are kept stable.

Description

Technical Field

[0001] The present disclosure relates to the field of chemical industry, and in particular to the field of heat exchange medium adjustment technology. Background Art

[0002] Fixed bed is a very common type of reactor in chemical production. A certain amount of catalyst is loaded into the reactor, and the material (material) enters the reactor at a certain temperature. A reaction occurs under the action of the catalyst, and the reaction product enters the downstream for further separation to obtain the final product.

[0003] However, process adjustments are difficult to avoid in chemical production, especially adjustments to production load or changes in material ratios, which lead to fluctuations in reactor inlet temperature and changes in adiabatic temperature rise, seriously affecting reactor conversion rate and selectivity, and making it impossible to ensure stable production quality. However, the existing technology does not have a corresponding solution. Summary of the invention

[0004] The present disclosure provides a heat exchange medium adjustment method, device, equipment and storage medium.

[0005] According to a first aspect of the present disclosure, a heat exchange medium adjustment method is provided. The method comprises:

[0006] Obtaining a fitting curve between the reactor residence time and the optimal reactor inlet temperature, wherein the reactor residence time is used to characterize the reaction time of the material entering the reactor in the reactor;

[0007] According to the fitting curve, determining the current optimal reactor inlet temperature;

[0008] Calculating a target thermal enthalpy value of the heat exchanger according to the current optimal reactor inlet temperature and an inlet temperature of a heat exchanger connected to the reactor;

[0009] Calculating the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger;

[0010] The flow rate of the heat exchange medium of the heat exchanger is adjusted according to the target thermal enthalpy value and the actual thermal enthalpy value.

[0011] According to the above aspects and any possible implementation, an implementation is further provided, wherein obtaining a fitting curve between the reactor residence time and the optimal reactor inlet temperature comprises:

[0012] Obtain historical catalyst volume and corresponding historical material mass flow rate;

[0013] Calculating a historical reactor residence time based on the historical catalyst volume and the historical material mass flow rate;

[0014] Obtaining a historical optimal reactor inlet temperature corresponding to the historical reactor residence time;

[0015] The historical reactor residence time is fitted with the historical optimal reactor inlet temperature to obtain the fitting curve.

[0016] According to the above aspects and any possible implementation, an implementation is further provided, wherein determining the current optimal reactor inlet temperature according to the fitting curve comprises:

[0017] Obtain the measured catalyst volume and the measured material mass flow rate;

[0018] Calculating the measured reactor residence time based on the measured catalyst volume, the measured material mass flow rate and the material density;

[0019] The current optimal reactor inlet temperature is calculated according to the measured reactor residence time and the fitting curve.

[0020] According to the above aspects and any possible implementation, an implementation is further provided, wherein the target enthalpy value of the heat exchanger is calculated according to the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger connected to the reactor, comprising:

[0021] Calculating a first temperature difference between the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger;

[0022] Obtain the measured material mass flow rate;

[0023] The target thermal enthalpy value is calculated according to the material specific heat capacity, the measured material mass flow rate and the first temperature difference.

[0024] According to the above aspects and any possible implementation, an implementation is further provided, wherein the measured inlet and outlet temperatures of the heat exchanger include: the heating medium feed temperature and the heating medium discharge temperature of the heater,

[0025] The actual thermal enthalpy value of the heat exchanger includes: the actual thermal enthalpy value of the heater;

[0026] The step of calculating the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger comprises:

[0027] Calculating a second temperature difference between the heating medium feed temperature and the heating medium discharge temperature;

[0028] Obtain the current measured heating medium mass flow rate;

[0029] The actual thermal enthalpy value of the heater is calculated according to the heat capacity of the heating medium in a condensed state, the currently measured mass flow rate of the heating medium, the second temperature difference and the latent heat of vaporization of the heating medium.

[0030] According to the above aspects and any possible implementation, an implementation is further provided, wherein the measured inlet and outlet temperatures of the heat exchanger include: the cooling medium feed temperature and the cooling medium outlet temperature of the cooler,

[0031] The actual enthalpy value of the heat exchanger includes: the actual enthalpy value of the cooler;

[0032] The step of calculating the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger comprises:

[0033] Calculating a third temperature difference between the cooling medium discharge temperature and the cooling medium feed temperature;

[0034] Get the current measured cooling medium mass flow rate;

[0035] The actual thermal enthalpy value of the cooler is calculated according to the heat capacity of the cooling medium, the currently measured cooling medium mass flow rate, and the third temperature difference.

[0036] According to the above aspects and any possible implementation manner, an implementation manner is further provided, wherein the flow rate of the heat exchange medium of the heat exchanger is adjusted according to the target enthalpy value and the actual enthalpy value, including:

[0037] If the target thermal enthalpy value is greater than the actual thermal enthalpy value, increasing the flow rate of the heat exchange medium of the heat exchanger;

[0038] If the target thermal enthalpy value is smaller than the actual thermal enthalpy value, the flow rate of the heat exchange medium of the heat exchanger is reduced.

[0039] According to a second aspect of the present disclosure, a heat exchange medium adjustment device is provided. The device comprises:

[0040] An acquisition module, used to acquire a fitting curve between a reactor residence time and an optimal reactor inlet temperature, wherein the reactor residence time is used to characterize the reaction time of the material entering the reactor in the reactor;

[0041] A determination module, used for determining the current optimal reactor inlet temperature according to the fitting curve;

[0042] A first calculation module, used for calculating a target thermal enthalpy value of the heat exchanger according to the current optimal reactor inlet temperature and an inlet temperature of a heat exchanger connected to the reactor;

[0043] A second calculation module is used to calculate the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger;

[0044] The adjustment module is used to adjust the flow rate of the heat exchange medium of the heat exchanger according to the target thermal enthalpy value and the actual thermal enthalpy value.

[0045] According to a third aspect of the present disclosure, an electronic device is provided, which includes a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the program, the method described above is implemented.

[0046] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the method according to the first aspect of the present disclosure is implemented.

[0047] In the present disclosure, the current optimal reactor inlet temperature can be determined by obtaining a fitting curve, and then the target enthalpy value of the heat exchanger can be accurately calculated based on the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger, and then the actual enthalpy value of the heat exchanger can be accurately calculated based on the measured inlet and outlet temperatures of the heat exchanger. Finally, based on the difference between the target enthalpy value and the actual enthalpy value, the flow rate of the heat exchange medium of the heat exchanger can be automatically adjusted to ensure that no matter whether the reactor inlet temperature fluctuates and the adiabatic temperature rise changes due to the adjustment of the production load or the change of the material ratio, the reactor inlet temperature can be re-optimized by adjusting the heat exchange medium flow rate to make it close to or equal to the current optimal reactor inlet temperature, thereby keeping the conversion rate and selectivity of the reactor stable, thereby ensuring stable production quality.

[0048] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present disclosure, nor are they intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The above and other features, advantages and aspects of the embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present disclosure. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, among which:

[0050] Figure 1 A flow chart showing a heat exchange medium adjustment method according to an embodiment of the present disclosure is shown;

[0051] Figure 2 A schematic diagram showing the connection relationship between a heat exchanger and a reactor according to an embodiment of the present disclosure is shown;

[0052] Figure 3A block diagram of a heat exchange medium adjustment device according to an embodiment of the present disclosure is shown;

[0053] Figure 4 A block diagram of an exemplary electronic device capable of implementing embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0055] In addition, the term "and / or" in this article is only a description of the association relationship between the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0056] Figure 1 A flow chart of a heat exchange medium adjustment method 100 according to an embodiment of the present disclosure is shown. The method 100 may include:

[0057] Step 110, obtaining a fitting curve between the reactor residence time and the optimal reactor inlet temperature, wherein the reactor residence time is used to characterize the reaction time of the material entering the reactor in the reactor;

[0058] There are generally multiple materials, and the reactor residence time can be the ratio between the volume of the catalyst and the material volume flow rate, which is used to characterize the reaction time of the material entering the reactor in the reactor, while the material volume flow rate is the volume of the material entering the reactor per unit time.

[0059] The optimal reactor inlet temperature refers to the optimal inlet temperature of the fixed bed reactor, and is also the temperature with the best reactor conversion rate and production quality among the multiple temperatures measured by the thermometer Tout.

[0060] Step 120, determining the current optimal reactor inlet temperature according to the fitting curve;

[0061] Step 130, calculating a target thermal enthalpy value of the heat exchanger according to the current optimal reactor inlet temperature and an inlet temperature of a heat exchanger connected to the reactor;

[0062] The enthalpy value is the heat exchange amount required in the heat exchanger, the target enthalpy value is the expected enthalpy value of the heat exchanger, and the actual enthalpy value is the actually calculated enthalpy value of the heat exchanger.

[0063] Step 140, calculating the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger;

[0064] Step 150: adjusting the flow rate of the heat exchange medium of the heat exchanger according to the target thermal enthalpy value and the actual thermal enthalpy value.

[0065] The current optimal reactor inlet temperature can be determined by obtaining the fitting curve, and then the target enthalpy value of the heat exchanger can be accurately calculated based on the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger, and then the actual enthalpy value of the heat exchanger can be accurately calculated based on the measured inlet and outlet temperatures of the heat exchanger. Finally, the flow rate of the heat exchange medium of the heat exchanger can be automatically adjusted based on the difference between the target enthalpy value and the actual enthalpy value, thereby ensuring that no matter whether the reactor inlet temperature fluctuates and the adiabatic temperature rise changes due to the adjustment of the production load or the change of the material ratio, the reactor inlet temperature can be re-optimized by adjusting the heat exchange medium flow rate to make it close to or equal to the current optimal reactor inlet temperature, thereby keeping the conversion rate and selectivity of the reactor stable, thereby ensuring stable production quality.

[0066] In some embodiments, obtaining a fitting curve between the reactor residence time and the optimal reactor inlet temperature comprises:

[0067] Obtain historical catalyst volume and corresponding historical material mass flow rate;

[0068] Calculating a historical reactor residence time based on the historical catalyst volume and the historical material mass flow rate;

[0069] The calculation formula for residence time is: Wherein, V is the volume of the catalyst, Fi is the mass flow rate of the i-th material, i ranges from 1 to n, and ρ is the material density (obtained by querying relevant data, which is the average material density of n materials).

[0070] The historical material mass flow rate is the historical mass of the material entering the reactor per unit time.

[0071] Obtaining a historical optimal reactor inlet temperature corresponding to the historical reactor residence time;

[0072] The historical reactor residence time is fitted with the historical optimal reactor inlet temperature to obtain the fitting curve.

[0073] The historical reactor residence time can be calculated based on the historical catalyst volume and the historical material mass flow rate, and then the historical reactor residence time is fitted with the corresponding historical optimal reactor inlet temperature to obtain the fitting curve.

[0074]

[0075] Wherein, T is the optimal reactor inlet temperature, A and B are the fitted coefficients, V is the catalyst volume of the fixed bed reactor (actual loading amount), Fi is the material mass flow rate (measured), ρ is the reactor feed material density (obtained by querying relevant data, average material density), is the residence time, and the value of i ranges from 1 to n.

[0076] In some embodiments, determining the current optimal reactor inlet temperature according to the fitting curve comprises:

[0077] Obtain the measured catalyst volume and the measured material mass flow rate;

[0078] Calculating the measured reactor residence time based on the measured catalyst volume, the measured material mass flow rate and the material density;

[0079] The current optimal reactor inlet temperature is calculated according to the measured reactor residence time and the fitting curve.

[0080] The measured reactor residence time can be calculated by the residence time calculation formula, and then the measured reactor residence time is substituted into the above fitting curve to calculate the current optimal reactor inlet temperature T.

[0081] In some embodiments, the calculating the target enthalpy value of the heat exchanger according to the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger connected to the reactor comprises:

[0082] Calculating a first temperature difference between the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger;

[0083] If it is necessary to use a heater to heat the heat exchange medium, the first temperature difference = the current optimal reactor inlet temperature T - the inlet temperature Tin of the heat exchanger,

[0084] If a cooler is required to cool the heat exchange medium, the first temperature difference = the inlet temperature Tin of the heat exchanger - the current optimal reactor inlet temperature T.

[0085] Obtain the measured material mass flow rate;

[0086] The target thermal enthalpy value is calculated according to the material specific heat capacity, the measured material mass flow rate and the first temperature difference.

[0087] By calculating the first temperature difference between the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger and obtaining the measured material mass flow rate, the material specific heat capacity, the measured material mass flow rate and the first temperature difference can be multiplied to automatically and accurately calculate the target thermal enthalpy value.

[0088] If heating is required: target enthalpy value Hduty (can be replaced by

[0089] If cooling is required: target enthalpy value Hduty (can be replaced by Where C is the specific heat capacity of the material (the average of the specific heat capacities of n materials), That is, the measured material mass flow rate (also the sum of the material mass flow rates of n types of materials), (T-Tin) or (Tin-T) is the first temperature difference.

[0090] In some embodiments, the measured inlet and outlet temperatures of the heat exchanger include: the heating medium feed temperature of the heater (T hin Measured th) and heating medium discharge temperature (T hout Measured th),

[0091] The actual thermal enthalpy value of the heat exchanger includes: the actual thermal enthalpy value of the heater;

[0092] The step of calculating the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger comprises:

[0093] Calculating a second temperature difference between the heating medium feed temperature and the heating medium discharge temperature;

[0094] Get the current measured heating medium mass flow F h ;

[0095] According to the heat capacity Ch of the heating medium in the condensed state, the currently measured mass flow rate of the heating medium, the second temperature difference ((th-th)) and the latent heat of vaporization H of the heating medium latent , calculate the actual thermal enthalpy value F of the heater 2(x) .

[0096] According to the heat capacity of the heating medium in the condensed state, the currently measured mass flow rate of the heating medium, the second temperature difference and the latent heat of vaporization of the heating medium, the actual thermal enthalpy value of the heater can be automatically and accurately calculated, that is, the actual heat consumed by the heater when heating the material using the heating medium.

[0097] Actual enthalpy value Hduty (i.e. F2(x)) = Fh*H latent +Ch*Fh*(thin-thout)

[0098] Among them, Fh is the current measured heating medium mass flow rate, H latent is the latent heat of vaporization of the heating medium (obtained by querying relevant data), Ch is the condensation heat capacity of the heating medium (i.e. the heat capacity of the heating medium in the condensation state after heating the material, obtained by querying relevant data), thin is the heating medium feed temperature (measured), and thout is the heating medium condensation temperature (i.e. the heating medium discharge temperature).

[0099] In some embodiments, the measured inlet and outlet temperatures of the heat exchanger include: the cooling medium feed temperature of the cooler (tcin measured by thermometer Tcin) and the cooling medium discharge temperature (tcout measured by thermometer Tcout),

[0100] The actual enthalpy value of the heat exchanger includes: the actual enthalpy value of the cooler;

[0101] The step of calculating the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger comprises:

[0102] Calculating a third temperature difference ((tcout-tcin)) between the cooling medium outlet temperature and the cooling medium feed temperature;

[0103] Get the current measured cooling medium mass flow rate;

[0104] The actual thermal enthalpy value of the cooler is calculated according to the heat capacity Cc of the cooling medium, the currently measured cooling medium mass flow Fc, and the third temperature difference.

[0105] After calculating the third temperature difference, the currently measured cooling medium mass flow rate can be obtained, and then the heat capacity Cc of the cooling medium, the currently measured cooling medium mass flow rate Fc, and the third temperature difference are multiplied together to accurately calculate the actual thermal enthalpy value of the cooler, that is, the actual heat obtained by the cooler when using the cooling medium to cool the material.

[0106] Actual enthalpy value Hduty (i.e. F3(x)) = Cc*Fc*(tcout-tcin)

[0107] Among them, Fc is the current measured mass flow rate of the cooling medium, Cc is the heat capacity of the cooling medium (obtained by querying relevant data), tcin is the cooling medium feed temperature, and tcout is the cooling medium discharge temperature.

[0108] In some embodiments, adjusting the flow rate of the heat exchange medium of the heat exchanger according to the target enthalpy value and the actual enthalpy value includes:

[0109] If the target thermal enthalpy value is greater than the actual thermal enthalpy value, increasing the flow rate of the heat exchange medium of the heat exchanger;

[0110] If the target thermal enthalpy value is smaller than the actual thermal enthalpy value, the flow rate of the heat exchange medium of the heat exchanger is reduced.

[0111] If the target enthalpy value is greater than the actual enthalpy value, it means that the actual heat exchange capacity of the heat exchanger is relatively large, and the production load may have increased or the material ratio may have increased. Therefore, it is necessary to increase the flow rate of the heat exchange medium of the heat exchanger. In this way, the temperature fluctuation of the reactor can be avoided to the greatest extent by pre-adjusting the heat exchange enthalpy value of the heat exchange medium in the heat exchanger to ensure stable production quality.

[0112] If the target enthalpy value is less than the actual enthalpy value, it means that the actual heat exchange capacity of the heat exchanger is relatively small, and the production load may be reduced or the material ratio may be reduced. Therefore, it is necessary to reduce the flow rate of the heat exchange medium of the heat exchanger. In this way, the temperature fluctuation of the reactor can be avoided to the greatest extent by pre-adjusting the heat exchange enthalpy value of the heat exchange medium in the heat exchanger to ensure stable production quality.

[0113] The following will be combined Figure 2 The technical solution of the present disclosure is further described in detail:

[0114] The present disclosure can be applied to one fixed bed reactor or multiple fixed bed reactors connected in series or in parallel, and the bed volume V, two or more streams of materials are mixed in a manifold and then heated or cooled in a heat exchanger to be adjusted to a suitable temperature T, and an adiabatic reaction occurs in the fixed bed to achieve the expected reaction conversion rate and selectivity.

[0115] A separate flow meter is installed on the feed pipeline of each material to measure the real-time mass flow rate Fi of the material. The material after the manifold is heat exchanged through the heat exchanger. The inlet and outlet pipelines are equipped with thermometers to measure Tin and Tout and send them to the temperature controller TIC. By adjusting the flow rate of the material through the heater HE and the cooler CE as well as the flow rates of the heating medium and the cooling medium Fh and Fc, the inlet material temperature of the reactor is adjusted in real time. The inlet and outlet pipelines of the heating medium and the cooling medium are equipped with thermometers to measure the medium temperatures thin, thout, tcin, and tcout in real time, and the heat exchanger load is calculated based on the thermal enthalpy method.

[0116] The branch pipelines before the mixed total feed enters the heater HE and the cooler CE are equipped with regulating valves TV1 and TV3, and the heating medium and cooling medium pipelines are equipped with regulating valves TV2 and TV4. The corresponding relationship between the reactor residence time and the optimal reactor inlet temperature is obtained based on historical experimental data, fitted into a relationship, and input into the control system.

[0117] Table 1 Correspondence between reactor residence time and optimal reactor inlet temperature

[0118]

[0119]

[0120] The relationship between the reactor inlet temperature control setting value (Tout, i.e., the optimal reactor inlet temperature) and the residence time obtained by fitting the data in Table 1 is as follows:

[0121]

[0122] Wherein, T is the optimal reactor inlet temperature, A and B are the fitted coefficients, V is the catalyst volume of the fixed bed reactor (actual loading amount), Fi is the material mass flow rate (measured), ρ is the reactor feed material density (obtained by querying relevant data, average material density), is the residence time, and the value of i ranges from 1 to n.

[0123] By comparing the heat exchanger inlet temperature tin with the optimal reactor inlet temperature T, determine whether the material needs to be heated or cooled. If heating is required, open TV1, close TV3, and adjust the hot medium flow rate to control the reactor feed temperature; if cooling is required, close TV1, open TV3, and adjust the cold medium flow rate to control the reactor material temperature.

[0124] The heat load required for heat exchange is calculated based on the feed flow rate and the material temperature before the heat exchanger. Given the TIC setting value, the heat exchange enthalpy value of the corresponding heating medium or cooling medium is controlled. The calculation formula F1(x) is expressed as follows:

[0125] If heating is required: target enthalpy value Hduty (can be replaced by

[0126] If cooling is required: target enthalpy value Hduty (can be replaced by Where C is the specific heat capacity of the material, That is, the measured material mass flow rate (also the sum of the material mass flow rates of n types of materials), (T-Tin) or (Tin-T) is the first temperature difference.

[0127] Actual enthalpy value Hduty (i.e. F2(x)) = Fh*H latent +Ch*Fh*(thin-thout)

[0128] Among them, Fh is the current measured mass flow rate of the heating medium, Hlatent is the latent heat of vaporization of the heating medium (obtained by querying relevant data), Ch is the condensation heat capacity of the heating medium (that is, the heat capacity of the heating medium when it is in a condensation state, obtained by querying relevant data), thin is the heating medium feed temperature (measured), and thout is the heating medium condensation temperature (measured, that is, the heating medium discharge temperature).

[0129] The calculation formula for the cooling medium enthalpy value F3(x) is as follows:

[0130] Actual enthalpy value Hduty (i.e. F3(x)) = Cc*Fc*(tcout-tcin)

[0131] Among them, Fc is the current measured mass flow rate of the cooling medium, Cc is the heat capacity of the cooling medium (obtained by querying relevant data), tcin is the cooling medium feed temperature, and tcout is the cooling medium discharge temperature.

[0132] The control strategy provided by the present disclosure adjusts the enthalpy load of the heating medium or the cooling medium through the measured material feed flow rate and temperature and through model calculation, and adjusts the reactor inlet temperature in real time to ensure that the conversion rate and selectivity of the fixed bed reactor are within the process requirements.

[0133] The details are as follows

[0134] The corresponding relationship between the reactor residence time and the optimal reactor inlet temperature is determined based on the experimental data and operation data, fitted into a relational expression, and written into the DCS calculation module.

[0135] The residence time is calculated based on the measured material feed flow rate Fn and the reactor catalyst bed volume V, according to the relationship fitted in the previous step

[0136]

[0137] The optimal reactor inlet temperature is determined by calculation through the DCS calculation module.

[0138] Based on the measured temperature Tin of the material main pipe before the heat exchanger and the comparison with the optimal reactor inlet temperature T, the DCS control module determines whether the material needs to be heated or cooled.

[0139] The enthalpy load expression required by the temperature controller to calculate the heater or cooler is as follows:

[0140] If heating is required: target enthalpy value Hduty (can be replaced by

[0141] If cooling is required: target enthalpy value Hduty (can be replaced by Write the above formula into the DCS calculation module, and input C, Fn, T, and Tin into the calculation function block.

[0142] The calculated enthalpy load is the enthalpy load of the heating medium or cooling medium heat exchange, and the enthalpy load of the heating medium or cooling medium can be directly controlled, where:

[0143] The calculation formula for the enthalpy value of the heating medium F2(x) is as follows:

[0144] Actual enthalpy value Hduty (i.e. F2(x)) = Fh*H latent +Ch*Fh*(thin-thout)

[0145] The calculation formula for the cooling medium enthalpy value F3(x) is as follows:

[0146] Actual enthalpy value Hduty (i.e. F3(x)) = Cc*Fc*(tcout-tcin)

[0147] The above formula is written into the DCS calculation module, and the enthalpy load of the heating medium or cooling medium is adjusted in real time according to the enthalpy load output by the TIC controller.

[0148] After the scheme is configured, DCS related parameters such as PID parameters need to be adjusted before it is put into use.

[0149] Example 1

[0150] The present disclosure is explained by taking a fixed bed reactor as an example.

[0151] The catalyst bed of a fixed bed reactor is 4.5m3. The corresponding relationship between the reactor residence time and the optimal reactor inlet temperature is as follows:

[0152] Table 2 Correspondence between reactor residence time and optimal reactor inlet temperature

[0153] Reactor residence time t / h Optimum reactor inlet temperature T / ℃ 1.4 98.3 1.45 97.2 1.5 96 1.548 95 1.6 93.6 1.65 92.8 1.7 92

[0154] The fitting relationship between the reactor residence time and the optimal reactor inlet temperature is obtained by fitting:

[0155]

[0156] As the production load (the sum of the target product and by-products) changes, the conversion rate and selectivity change as shown in the following table:

[0157] Table 3 Correspondence between reactor residence time and optimal reactor inlet temperature

[0158]

[0159]

[0160] After the fixed bed reactor adopts the new control strategy, no manual operation is required when the feed load is adjusted, and the reactor feed temperature is automatically adjusted, and the control loop responds quickly. Although the temperature adjustment slightly affects the reaction conversion rate, it can enable the reactor to achieve a better conversion rate and selectivity, with better economic benefits, and will not cause large process fluctuations.

[0161] Comparative Example 1

[0162] Taking the fixed bed reactor as an example, if the control strategy provided by this patent is not adopted, as the production load changes, the conversion rate and selectivity change as shown in the following table:

[0163] Table 4 Correspondence between reactor residence time and optimal reactor inlet temperature

[0164]

[0165] If the control strategy provided by the present invention is not adopted, after the production load changes, the reaction selectivity changes due to the change in residence time, and the proportion of the target product is significantly reduced. Because the reactor feed temperature is not adjusted, the conversion rate is relatively high, but it is not economical in terms of overall economic benefits.

[0166] Through comparative analysis of the results, it is found that after adopting the new control method, when the production load is adjusted, the fixed bed reactor can maintain a relatively economical conversion rate and selectivity, which can greatly improve the production level and product quality.

[0167] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should be aware that the present disclosure is not limited by the order of the actions described, because according to the present disclosure, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present disclosure.

[0168] The above is an introduction to the method embodiment. The following is a further explanation of the scheme disclosed in the present invention through an apparatus embodiment.

[0169] Figure 3 FIG. 3 shows a block diagram of a heat exchange medium adjustment device 300 according to an embodiment of the present disclosure. Figure 3 As shown, the device 300 includes:

[0170] An acquisition module 310 is used to acquire a fitting curve between the reactor residence time and the optimal reactor inlet temperature, wherein the reactor residence time is used to characterize the reaction time of the material entering the reactor in the reactor;

[0171] A determination module 320, for determining a current optimal reactor inlet temperature according to the fitting curve;

[0172] A first calculation module 330, configured to calculate a target thermal enthalpy value of the heat exchanger according to the current optimal reactor inlet temperature and an inlet temperature of a heat exchanger connected to the reactor;

[0173] A second calculation module 340 is used to calculate the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger;

[0174] The adjustment module 350 is used to adjust the flow rate of the heat exchange medium of the heat exchanger according to the target thermal enthalpy value and the actual thermal enthalpy value.

[0175] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the described module can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0176] According to an embodiment of the present disclosure, the present disclosure also provides an electronic device and a non-transitory computer-readable storage medium storing computer instructions.

[0177] Figure 4 A schematic block diagram of an electronic device 400 that can be used to implement an embodiment of the present disclosure is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present disclosure described and / or required herein.

[0178] The device 400 includes a computing unit 401, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 402 or a computer program loaded from a storage unit 408 into a random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the device 400 can also be stored. The computing unit 401, the ROM 402, and the RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0179] A number of components in the device 400 are connected to the I / O interface 405, including: an input unit 406, such as a keyboard, a mouse, etc.; an output unit 407, such as various types of displays, speakers, etc.; a storage unit 408, such as a disk, an optical disk, etc.; and a communication unit 409, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 409 allows the device 400 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0180] The computing unit 401 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 401 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 401 performs the various methods and processes described above, such as method 100. For example, in some embodiments, the method 100 may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 408. In some embodiments, part or all of the computer program may be loaded and / or installed on the device 400 via ROM 402 and / or communication unit 409. When the computer program is loaded into RAM 403 and executed by the computing unit 401, one or more steps of the method 100 described above may be performed. Alternatively, in other embodiments, the computing unit 401 may be configured to perform the method 100 in any other appropriate manner (e.g., by means of firmware).

[0181] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0182] The program code for implementing the method of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0183] In the context of the present disclosure, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0184] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0185] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0186] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

[0187] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document does not limit this.

[0188] The above specific implementations do not constitute a limitation on the protection scope of the present disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A method for adjusting a heat exchange medium, characterized in that: include: Obtaining a fitting curve between the reactor residence time and the optimal reactor inlet temperature, wherein the reactor residence time is used to characterize the reaction time of the material entering the reactor in the reactor; According to the fitting curve, determining the current optimal reactor inlet temperature; Calculating a target thermal enthalpy value of the heat exchanger according to the current optimal reactor inlet temperature and an inlet temperature of a heat exchanger connected to the reactor; Calculating the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger; The flow rate of the heat exchange medium of the heat exchanger is adjusted according to the target thermal enthalpy value and the actual thermal enthalpy value.

2. The method according to claim 1, characterized in that The step of obtaining a fitting curve between the reactor residence time and the optimal reactor inlet temperature comprises: Obtain historical catalyst volume and corresponding historical material mass flow rate; Calculating a historical reactor residence time based on the historical catalyst volume and the historical material mass flow rate; Obtaining a historical optimal reactor inlet temperature corresponding to the historical reactor residence time; The historical reactor residence time is fitted with the historical optimal reactor inlet temperature to obtain the fitting curve.

3. The method according to claim 1, characterized in that Determining the current optimal reactor inlet temperature according to the fitting curve comprises: Obtain the measured catalyst volume and the measured material mass flow rate; Calculating the measured reactor residence time based on the measured catalyst volume, the measured material mass flow rate and the material density; The current optimal reactor inlet temperature is calculated according to the measured reactor residence time and the fitting curve.

4. The method according to claim 1, characterized in that: The step of calculating the target enthalpy value of the heat exchanger according to the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger connected to the reactor comprises: Calculating a first temperature difference between the current optimal reactor inlet temperature and the inlet temperature of the heat exchanger; Obtain the measured material mass flow rate; The target thermal enthalpy value is calculated according to the material specific heat capacity, the measured material mass flow rate and the first temperature difference.

5. The method according to claim 1, characterized in that The measured temperatures at the inlet and outlet of the heat exchanger include: the heating medium feed temperature and the heating medium discharge temperature of the heater, The actual thermal enthalpy value of the heat exchanger includes: the actual thermal enthalpy value of the heater; The calculating the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger comprises: Calculating a second temperature difference between the heating medium feed temperature and the heating medium discharge temperature; Obtain the current measured heating medium mass flow rate; The actual thermal enthalpy value of the heater is calculated according to the heat capacity of the heating medium in a condensed state, the currently measured mass flow rate of the heating medium, the second temperature difference and the latent heat of vaporization of the heating medium.

6. The method according to claim 1, characterized in that The measured inlet and outlet temperatures of the heat exchanger include: the cooling medium feed temperature and the cooling medium discharge temperature of the cooler. The actual enthalpy value of the heat exchanger includes: the actual enthalpy value of the cooler; The calculating the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger comprises: Calculating a third temperature difference between the cooling medium discharge temperature and the cooling medium feed temperature; Get the current measured cooling medium mass flow rate; The actual thermal enthalpy value of the cooler is calculated according to the heat capacity of the cooling medium, the currently measured cooling medium mass flow rate, and the third temperature difference.

7. The method according to any one of claims 1 to 6, characterized in that The adjusting the flow rate of the heat exchange medium of the heat exchanger according to the target enthalpy value and the actual enthalpy value includes: If the target thermal enthalpy value is greater than the actual thermal enthalpy value, increasing the flow rate of the heat exchange medium of the heat exchanger; If the target thermal enthalpy value is smaller than the actual thermal enthalpy value, the flow rate of the heat exchange medium of the heat exchanger is reduced.

8. A heat exchange medium adjustment device, characterized in that: include: An acquisition module, used to acquire a fitting curve between a reactor residence time and an optimal reactor inlet temperature, wherein the reactor residence time is used to characterize the reaction time of the material entering the reactor in the reactor; A determination module, used for determining the current optimal reactor inlet temperature according to the fitting curve; A first calculation module, used for calculating a target thermal enthalpy value of the heat exchanger according to the current optimal reactor inlet temperature and an inlet temperature of a heat exchanger connected to the reactor; A second calculation module is used to calculate the actual thermal enthalpy value of the heat exchanger according to the measured inlet and outlet temperatures of the heat exchanger; The adjustment module is used to adjust the flow rate of the heat exchange medium of the heat exchanger according to the target thermal enthalpy value and the actual thermal enthalpy value.

9. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to cause the computer to execute the method according to any one of claims 1-7.

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