Method and system for optimizing united station design based on pinch point technology

Abstract

The invention provides a method and system for optimizing the design of a united station based on a pinch point technology, and the method comprises the steps: analyzing the related operation parameters and energy consumption conditions of the onsite technological process of the united station, determining a hot material flow and a cold material flow, and calculating the corresponding heat load and heat capacity flow rate; performing temperature zone division based on the initial temperature and the target temperature of each hot material flow and each cold material flow, and analyzing each temperature zone by using a problem table method to determine pinch points of the heat exchange network of the united station; optimizing, analyzing and determining a target pinch point temperature difference; the transformation measures of the united station are analyzed and determined by taking the pinch point temperature as the boundary and combining the set rule, and the energy utilization rate is improved. By adopting the scheme, the problems of incomplete consideration of indexes, high calculation time consumption and the like in the prior art can be solved, the short plates in the heat exchange process of the united station are determined based on pinch point analysis thoughts in combination with economic analysis for reconstruction design, and the energy utilization rate of the united station is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield joint station gathering and transportation optimization, and in particular to a method and system for optimizing joint station design based on pinch point technology. Background Art

[0002] The current thermal analysis technologies for joint stations mainly include: There are two methods: analytical method and energy balance method. The analysis method is mainly used to analyze the subsystems of the joint station or a single device. Analysis, for example, by calculating the value of each material flow and energy flow of the heat exchange equipment such as boilers and heating furnaces in the joint station, using The energy balance method evaluates and analyzes system energy usage, identifies weak links in energy use through analysis of test data, and implements energy-saving improvements. The energy balance method analyzes the energy conversion, utilization, and loss of each device in the joint station. It balances the income and expenditure of energy flows, determines the distribution of energy losses, and calculates energy utilization efficiency. This allows the identification of inefficient areas for energy-saving improvements.

[0003] When using existing technologies to implement energy utilization analysis, the main focus is on evaluating a single device. The evaluation indicators are single and cannot reflect the overall energy consumption of the joint station. It is impossible to optimize and analyze specific heat exchange links, making it difficult to conduct an overall system evaluation and improvement of the joint station. In addition, the process of calculating the evaluation indicators is labor-intensive, and parameter preparation and indicator calculation are time-consuming, which affects the timeliness of the analysis.

[0004] The information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art known to those skilled in the art. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a method for optimizing the design of a joint station based on pinch point technology. The method is based on a method and system for optimizing the design of a joint station based on pinch point technology. The method analyzes the relevant operating parameters and energy consumption of the on-site process flow of the joint station, determines the hot logistics and cold logistics, and calculates the corresponding heat load and heat capacity flow rate; divides the temperature zones based on the initial temperature and target temperature of each hot logistics and cold logistics, and uses the problem table method to analyze each temperature zone to determine the pinch point of the heat exchange network of the joint station; then optimizes and analyzes to determine the target pinch point temperature difference; uses the pinch point temperature as the limit and combines the set rules to analyze and determine the transformation measures of the joint station to improve energy utilization. The adoption of this solution can overcome the problems of incomplete consideration of indicators and time-consuming calculations in the existing technology. Based on the pinch point analysis idea combined with economic analysis, the shortcomings in the heat exchange process of the joint station are determined for transformation and design, thereby improving the energy utilization of the joint station. Preferably, in one embodiment, the method includes:

[0006] Step S10: Analyze the relevant operating parameters and energy consumption of the on-site process flow of the joint station to be processed, and determine the hot logistics and cold logistics;

[0007] Step S20: Calculate the heat load and heat capacity flow rate of the hot stream and the cold stream respectively;

[0008] Step S30: Divide the temperature zones based on the initial temperature and target temperature of each hot stream and cold stream, and analyze each temperature zone using the problem table method to determine the pinch points of the combined station heat exchange network;

[0009] Step S40: Optimize and analyze to determine the target pinch point temperature difference;

[0010] Step S50: Based on the heat exchange network, the heat exchange between logistics is matched with the pinch point temperature as the boundary, and the transformation measures of the joint station are determined in combination with the set rules to improve energy utilization.

[0011] Optionally, in one embodiment, in step S10, the on-site process flow includes at least a crude oil processing process and a dilution heating process.

[0012] Furthermore, in one embodiment, in step S30, the process of dividing the temperature zones includes:

[0013] Preliminary setting of pinch point temperature difference △T min ;

[0014] Arrange the initial and target temperatures of the hot and cold streams in ascending order, and calculate the average temperature based on the initially set pinch point temperature difference;

[0015] Arrange the average temperatures of all hot and cold logistics in ascending order and divide them into temperature zones.

[0016] Specifically, in one embodiment, the process of analyzing each temperature zone using the problem table method to determine the pinch point of the combined station heat exchange network includes:

[0017] Perform heat balance calculation and heat cascade calculation for each temperature zone to determine the heat supply and heat discharge of the corresponding sub-network;

[0018] The interface of the temperature zone where the heat discharge meets the set requirements is selected as the pinch point.

[0019] Preferably, in one embodiment, the heat balance calculation is performed according to the following formula:

[0020] O k =I k -D k

[0021] D k =(∑CP cold -∑CP hot )(T k -T k+1 )

[0022] Where: O k Heat removed from the subnetwork, kW; I k Heat supplied to the subnetwork, kW; D k is the additional heat required for the kth temperature zone of the sub-network, kW; ∑CP cold is the sum of the heat capacity flow rates of the cold stream in the kth temperature zone, kW / ℃; ∑CP hot is the sum of the heat capacity flow rates of the heat flow in the kth temperature zone, kw / ℃; T k -T k+1 is the temperature interval of the kth temperature zone subnetwork; k is the number of temperature zones.

[0023] Furthermore, in an optional embodiment, in step S40, the total cost curve is determined by considering the heating utility volume, cooling utility volume and heat exchange area factors, and the pinch point temperature difference corresponding to the extreme point of the total cost curve is determined as the target pinch point temperature difference.

[0024] On the other hand, in an optional embodiment, in step S40, the target pinch point temperature difference is determined by a mathematical optimization estimation method based on the cold and hot composite temperature enthalpy curve.

[0025] Preferably, in one embodiment, in step S50, a pinch point analysis is performed on the energy-consuming equipment of the joint station, and the minimum utility heating and minimum utility cooling of the system are made consistent with the previously calculated values ​​by reasonably matching the heat exchange between logistics based on the heat exchange network.

[0026] Specifically, in an optional embodiment, in step S50, the transformation measures of the joint station are determined by analyzing the following rules:

[0027] The heat exchange network is divided into two parts above and below the pinch point. If the hot flow below the pinch point meets the set matching rules, a heat exchanger is set to allow the cold flow below the pinch point to exchange heat with it, and the remaining heat load of the hot flow is realized by the public cooler; if the cold flow above the pinch point meets the set matching rules, a heat exchanger is set to allow the cold flow above the pinch point to exchange heat with it, and the remaining heat load of the cold flow is realized by the public heater.

[0028] Based on other aspects of the method described in any one or more of the above embodiments, the present invention further provides a storage medium storing program codes that can implement the method described in any one or more of the above embodiments.

[0029] Based on the application aspects of the method described in any one or more of the above embodiments, the present invention also provides a system for optimizing joint station design based on pinch point technology, which executes the method described in any one or more of the above embodiments.

[0030] Compared with the closest prior art, the present invention also has the following beneficial effects:

[0031] The present invention provides a method and system for optimizing the design of a joint station based on pinch point technology. The method analyzes the operating parameters and energy consumption of the joint station's on-site process flow, determines the hot and cold logistics, and calculates the corresponding heat load and heat capacity flow rate. The embodiment of the present invention comprehensively analyzes the hot and cold logistics related to various processes in the joint station, fundamentally ensuring the comprehensiveness and rationality of the heat exchange network design.

[0032] Based on the initial and target temperatures of each hot and cold logistics stream, temperature zones are divided, and the problem table method is used to analyze each temperature zone to determine the pinch point of the heat exchange network of the joint station; then the target pinch point temperature difference is determined by optimization analysis; the pinch point temperature is used as the boundary and combined with the set rules to determine the transformation measures of the joint station to improve energy utilization; the required input parameters are greatly reduced, the calculation process is simplified, the requirements for on-site measured data are reduced, and the manpower and physical costs are reduced; the energy-saving potential of the heat exchange system of the joint station is reliably explored, and reasonable energy-saving transformation measures are proposed, combined with economic analysis, which is more in line with actual production conditions and is not limited to a single type of joint station. It has universality for improving the energy utilization rate of different joint stations.

[0033] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0035] Figure 1 1 is a flow chart of a method for optimizing joint station design based on pinch point technology provided by one embodiment of the present invention;

[0036] Figure 2 1. It is a schematic diagram of the oil-water treatment process flow of the joint station in the method for optimizing the design of the joint station based on the pinch point technology provided in an embodiment of the present invention;

[0037] Figure 3 1. It is a schematic diagram of a lean oil blending process flow of a joint station in a method for optimizing joint station design based on pinch point technology provided in an embodiment of the present invention;

[0038] Figure 4 This is an example diagram of the original heat exchange network corresponding to the joint station in the method for optimizing the joint station design based on the pinch point technology provided in an embodiment of the present invention;

[0039] Figure 5 This is an example diagram of a heat exchange network below the pinch point after optimization corresponding to a joint station in the method for optimizing joint station design based on the pinch point technology provided in an embodiment of the present invention;

[0040] Figure 6 This is an example diagram of a heat exchange network below the pinch point after optimization corresponding to a joint station in the method for optimizing joint station design based on the pinch point technology provided in an embodiment of the present invention;

[0041] Figure 7 It is a structural diagram of a system for optimizing joint station design based on pinch point technology provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0042] The following will describe in detail the implementation methods of the present invention in conjunction with the accompanying drawings and embodiments, so that practitioners of the present invention can fully understand how the present invention applies technical means to solve technical problems and achieve the implementation process of technical effects, and can implement the present invention in accordance with the above implementation process. It should be noted that as long as no conflict exists, the various embodiments and various features of each embodiment in the present invention can be combined with each other, and the resulting technical solutions are all within the scope of protection of the present invention.

[0043] Although the flowcharts depict the operations as sequential processes, many of the operations can be performed in parallel, concurrently, or simultaneously. The order of the operations can be rearranged. A process can be terminated when its operations are completed, but can also have additional steps not included in the figures. A process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0044] Computer devices include user devices and network devices. User devices or clients include, but are not limited to, computers, smartphones, and PDAs (Personal Digital Assistants). Network devices include, but are not limited to, a single network server, a server group consisting of multiple network servers, or a cloud computing-based cloud consisting of a large number of computers or network servers. Computer devices can operate independently to implement the present invention, or they can connect to a network and interact with other computer devices in the network to implement the present invention. The network in which the computer device resides includes, but is not limited to, the Internet, wide area networks, metropolitan area networks, local area networks, and VPN networks.

[0045] The terms used herein are intended only to describe specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "a", "an", "an item" used herein are also intended to include the plural. It should also be understood that the terms "comprise" and / or "include" used herein specify the presence of stated features, integers, steps, operations, units and / or components, and do not preclude the presence or addition of one or more other features, integers, steps, operations, units, components and / or combinations thereof.

[0046] The current thermal analysis technologies for joint stations mainly include: There are two methods: analytical method and energy balance method. The analysis method is mainly used to analyze the subsystems of the joint station or a single device. Analysis, for example, by calculating the value of each material flow and energy flow of the heat exchange equipment such as boilers and heating furnaces in the joint station, using Balanced approach to system energy evaluation and analysis,

[0047] Through Analyze the test data obtained by calculation to find the weak links in energy consumption and carry out energy-saving transformation. In actual operation, the test data includes Analytical calculations The location, distribution and size of the loss are calculated and used to evaluate and analyze energy consumption.

[0048] The energy balance method analyzes the energy conversion, utilization and loss of each device in the joint station, balances the income and expenditure of energy flow, determines the quantitative distribution of energy loss, calculates the energy utilization efficiency, and thus finds the inefficient parts and conducts energy-saving transformation.

[0049] The crude oil processing process of the joint station is relatively complex. When using existing technologies to implement energy utilization analysis, the main focus is on evaluating a single device. The evaluation indicators are single and cannot reflect the overall energy consumption of the joint station. It is impossible to optimize and analyze specific heat exchange links, making it difficult to conduct a holistic system evaluation and improvement of the joint station. In addition, the process of calculating the evaluation indicators is labor-intensive, and the parameter preparation and indicator calculation are time-consuming, affecting the timeliness of the analysis.

[0050] The researchers of this invention considered that pinch point technology can achieve significant energy savings and reduce environmental pollution. Applying pinch point analysis to the heat exchange process of the combined station can identify shortcomings and irrationalities in the combined station's heat exchange network and improve the energy utilization of the combined station.

[0051] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides a method for optimizing the design of a joint station based on pinch point technology. The pinch point technology is applied to the process flow of the joint station to analyze the existing heat exchange network, find out the energy-saving potential of the heat exchange system of the joint station, and propose reasonable energy-saving transformation measures. The application of this scheme can solve the problem of single evaluation indicators of the existing technology, conduct an overall comprehensive evaluation of the process system of the joint station, make the overall energy flow of the joint station better matched, overcome the problem of more indicator parameters required by the standard calculation process, efficiently and reliably guide the on-site variable operating condition operation of the joint station, and enhance the applicability in the oil field production process. At the same time, the overall heat exchange network control optimization of the joint station is realized, the energy-saving potential of the heat exchange system of the joint station is found, and reasonable energy-saving transformation measures are proposed.

[0052] Next, the detailed process of the method according to the embodiment of the present invention is described in detail based on the accompanying drawings. The steps shown in the flowcharts of the accompanying drawings can be executed in a computer system including, for example, a set of computer-executable instructions. Although the logical order of the steps is shown in the flowcharts, in some cases, the steps shown or described can be executed in a different order than here.

[0053] Example 1:

[0054] Figure 1 The flowchart of the method for optimizing the joint station design based on the pinch point technology provided by the first embodiment of the present invention is shown. Figure 1 It can be seen that the method includes the following steps.

[0055] Step S10: Analyze the relevant operating parameters and energy consumption of the on-site process flow of the joint station to be processed, and determine the hot logistics and cold logistics;

[0056] Step S20: Calculate the heat load and heat capacity flow rate of the hot stream and the cold stream respectively;

[0057] Step S30: Divide the temperature zones based on the initial temperature and target temperature of each hot stream and cold stream, and analyze each temperature zone using the problem table method to determine the pinch points of the combined station heat exchange network;

[0058] Step S40: Optimize and analyze to determine the target pinch point temperature difference;

[0059] Step S50: Based on the heat exchange network, the pinch point temperature is used as the limit and combined with the set rules to analyze and determine the transformation measures of the joint station to improve energy utilization.

[0060] This invention addresses the complex systems, high energy consumption, and high levels of waste heat in combined heat exchangers, as well as the often irrational energy utilization. The aim is to systematically evaluate and improve energy usage patterns across the combined heat exchanger, thereby increasing the overall energy utilization rate. Using pinch point technology based on the combined heat exchanger's comprehensive process flow, the existing heat exchanger network is analyzed. Combined with economic analysis, the energy-saving potential of the combined heat exchanger system is identified, and reasonable energy-saving optimization measures are proposed.

[0061] In the heat exchange network of the joint station, at the pinch point, the system heat transfer temperature difference is the smallest and the heat flow is zero, which limits the maximum heat recovery. To perform pinch point analysis, we first need to find the pinch point in the heat exchange network.

[0062] First, based on the overall energy consumption of the joint station, the present invention determines the joint station logistics data based on actual on-site operating parameters and calculations, and then calculates hot and cold logistics information. In one embodiment, in step S10, the hot and cold logistics are determined based on the on-site process flow operating parameters and energy consumption of the joint station to be processed. In other words, the overall energy consumption statistics of the joint station include both the crude oil processing process and the dilution heating process, and heat exchange matching is performed for both processes simultaneously.

[0063] In actual application, in an optional embodiment, the on-site process flow includes at least a crude oil processing process and a dilution heating process.

[0064] The heat load and heat capacity flow rate of the hot and cold streams are further calculated. Then, step S30 is performed to divide the temperature zones based on the initial and target temperatures of the hot and cold streams. The problem table method is used to analyze each temperature zone to determine the pinch point of the combined station heat exchange network.

[0065] The embodiment of the present invention uses a problem table method to find and analyze the pinch points of the combined station heat exchange network. The specific implementation logic includes:

[0066] Follow the steps below to divide the temperature zones:

[0067] Preliminary setting of pinch point temperature difference △T min ;

[0068] Arrange the initial and target temperatures of the hot and cold streams in ascending order and calculate the average temperature (hot stream temperature minus △T min / 2, cold logistics temperature plus △T min / 2, thus ensuring that there is △T between the cold and hot logistics min heat transfer temperature difference);

[0069] The average temperatures of all hot and cold logistics are shuffled and arranged in ascending order, and divided into temperature zones.

[0070] Then, the problem table method is used to analyze each temperature zone to determine the pinch points of the combined station heat exchange network, including:

[0071] Perform heat balance calculation and heat cascade calculation for each temperature zone to determine the heat supply and heat discharge of the corresponding sub-network;

[0072] The interface of the temperature zone where the heat discharge meets the set requirements is selected as the pinch point.

[0073] The embodiment of the present invention adopts a problem table method to find the pinch points of the combined station heat exchange network and perform analysis. The specific steps are as follows.

[0074] In the first step, find the cold and hot flows of the combined station and calculate the heat load and heat capacity flow rate.

[0075] The pinch point temperature difference is a variable value. In order to ensure that the heat exchange area and energy savings are within a reasonable range, the pinch point temperature cannot be too large or too small. A reasonable value must be selected. Therefore, the pinch point temperature difference △T is initially selected. min , and then optimize.

[0076] Then, the initial and target temperatures of the hot and cold streams are arranged in ascending order and the average temperature (the hot stream temperature minus ΔT) is calculated. min / 2, cold logistics temperature plus △T min / 2, thus ensuring that there is △T between the cold and hot logistics min heat transfer temperature difference),

[0077] Then arrange the average temperatures of all cold and hot logistics in ascending order, sort the processed data of cold and hot flows together according to the high and low temperatures, and divide them into temperature zones. After the cold and hot logistics are sorted, the area between the two temperatures is the temperature zone.

[0078] The second step is to perform temperature zone heat balance calculation and thermal cascade calculation in sequence according to the temperature zone division:

[0079] O k =I k -D k (1)

[0080] D k =(∑CP cold -∑CPhot )(T k -T k+1 ) (2)

[0081] Where: O k Heat removed from the subnetwork, kW; I k Heat supplied to the subnetwork, kW; D k is the additional heat required for the kth temperature zone of the sub-network, kW; ∑CP cold is the sum of the heat capacity flow rates of the cold stream in the kth temperature zone, kW / ℃; ∑CP hot is the sum of the heat capacity flow rates of the heat flow in the kth temperature zone, kw / ℃; T k -T k+1 is the temperature interval of the kth temperature zone subnetwork; k is the number of temperature zones, k = 1, 2, ...; it is a positive integer.

[0082] The third step is to determine the minimum heating utility volume. k When the value of is negative, the heat flux (heat supplied to the outside world) is a negative heat flux. The one with the largest absolute value in the negative heat flux is taken as the minimum heat input from the outside world, that is, the minimum heating utility. It is input from the first temperature zone, and then the heat flux between the temperature zones is calculated. The heat flowing out of the last temperature zone is the minimum cooling utility.

[0083] From the first to the third step, the cold and hot logistics of the joint station are counted, and the heat load and heat capacity flow rate are calculated. Then the data is processed. This is the step of pinch point analysis. The results can be expressed in tabular form. An example can be seen in Table 2 of the implementation case section.

[0084] The fourth step is to make a total composite curve where the heat flux between the temperature zones is zero, which is the pinch point. The horizontal coordinate position corresponding to H = 0 is the pinch point position.

[0085] Generally speaking, a smaller pinch point temperature difference results in greater heat recovery and reduced heating and cooling utility costs, but this increases the heat exchange area of ​​the heat exchanger, thereby increasing the equipment cost. A larger pinch point temperature difference results in less heat recovery and greater heating and cooling utility costs and expenses. The present invention analyzes both the heat exchanger equipment cost and the heat exchange area cost, reflecting both the equipment price and the heating and cooling utility costs, i.e., the operating costs of external heating or cooling. The total cost curve formed by the sum of these two factors has an extreme point corresponding to the optimal checkpoint temperature difference. The extreme point here refers to the minimum value, indicating the minimum total cost.

[0086] Therefore, in an optional embodiment, the process of optimizing and analyzing to determine the target pinch point temperature difference includes: determining the total cost curve by considering the heating utility volume, cooling utility volume and heat exchange area factors, and determining the pinch point temperature difference corresponding to the extreme point as the target pinch point temperature difference.

[0087] On the other hand, in an optional embodiment, the process of optimizing and analyzing to determine the target pinch point temperature difference may also employ the following logic:

[0088] Before optimizing the heat exchange network to achieve network synthesis, the target pinch point temperature difference is determined by mathematical optimization estimation method based on the hot and cold composite temperature enthalpy line.

[0089] In the embodiment of the present invention, a graphical method is used to determine the pinch point temperature difference; based on the cold and hot composite temperature enthalpy line, the curve in the figure is translated, and the difference is taken to estimate the minimum temperature difference between the cold and hot logistics, thereby obtaining the pinch point temperature difference.

[0090] Furthermore, after determining the optimal target pinch point temperature difference, step S50 is executed to determine the transformation measures of the joint station based on the pinch point temperature as a limit and the set rules to improve energy utilization.

[0091] The goal of pinch analysis is to recycle wasted energy for heating cold logistics, reducing utility heat load consumption and achieving energy savings. Optimizing and renovating heat exchange networks addressing irrational heat transfer. By adding heat exchange units to the existing network, the maximum amount of heat that can be recovered is determined, along with the minimum utility heating and cooling loads. By combining these two components, overall system energy savings can be achieved.

[0092] In step S50, after the pinch point temperature difference is determined, the original heat exchange network is created and optimized. A pinch point analysis is performed on the energy-consuming equipment in the combined station. Using the theoretical calculations above as a reference, the heat exchange network is modified. By rationally matching the heat exchange between logistics based on the heat exchange network, the system's minimum utility heating and minimum utility cooling capacities are aligned with the previously calculated values. The original heat exchange network diagram is then drawn, and the combined station's heat exchange network is modified.

[0093] Pinch point transformation uses the pinch point temperature as the boundary to divide the heat exchange network into two parts above and below the pinch point. If there are cooling utilities above the pinch point and heating utilities below the pinch point, it is unreasonable and the heat exchange network needs to be transformed.

[0094] Therefore, in one embodiment, in step S50, the transformation measures of the joint station are determined by combining the following rule analysis:

[0095] Using the pinch point temperature as the boundary, the heat exchange network is divided into two parts, above and below the pinch point. If the hot stream below the pinch point meets the set matching rules, a heat exchanger is set to allow the cold stream below the pinch point to exchange heat with it, and the remaining heat load of the hot stream is met by the utility cooler. If the cold stream above the pinch point meets the set matching rules, a heat exchanger is set to allow the cold stream above the pinch point to exchange heat with it, and the remaining heat load of the cold stream is met by the utility heater. In an optional embodiment, the set matching rules are as follows:

[0096] 1). Temperature is not transferred through the pinch point;

[0097] 2) No cold utility works are installed above the pinch point;

[0098] 3). No thermal utility works are set up below the pinch point.

[0099] The modification aspects of the pinch point analysis in the embodiment of the present invention combine the crude oil processing process and the dilution heating process, call on the resources in the joint station, and realize the coordination of the overall energy consumption of the joint station. The actual effect of the pinch point analysis and modification is: pinch point analysis is performed on the energy-consuming equipment of the entire joint station, heat exchange units are added to the original heat exchange network, the maximum heat that can be recovered in the network is determined, and the minimum utility heating load and the minimum utility cooling load are determined. Through the coordination of these two parts, the energy utilization rate of the joint station is improved.

[0100] The present invention is further described below with reference to examples of implementation. The scope of the present invention is not limited by the examples, but is set forth in the claims.

[0101] Take the process flow of the oil-water treatment system of a certain joint station as an example. This joint station mainly includes the main process flow of oil-water treatment and the thin oil mixing process.

[0102] The method for optimizing the design of a joint station based on the pinch point technology provided by the present invention is executed based on the joint station, including the following operations:

[0103] Step S10: Analyze the relevant operating parameters and energy consumption of the on-site process flow of the joint station to be processed, and determine the hot logistics and cold logistics;

[0104] Step S20: Calculate the heat load and heat capacity flow rate of the hot stream and the cold stream respectively;

[0105] Step S30: Divide the temperature zones based on the initial temperature and target temperature of each hot stream and cold stream, and analyze each temperature zone using the problem table method to determine the pinch points of the combined station heat exchange network;

[0106] Step S40: Optimize and analyze to determine the target pinch point temperature difference;

[0107] Step S50: Based on the heat exchange network, the pinch point temperature is used as the limit and combined with the set rules to analyze and determine the transformation measures of the joint station to improve energy utilization.

[0108] The main process flow and thin oil mixing process flow chart of the joint station are as follows Figure 2 As shown in the figure, the operating parameters of the on-site process are as follows: Figure 3 As shown in the figure, the combined station primarily utilizes heat from the wastewater in the settling tank and the steam after heat exchange. The temperatures of the wastewater in the settling tank and the steam after heat exchange are generally high. Direct discharge not only wastes energy but also causes thermal pollution. Therefore, pinch point technology was applied to optimize the design and renovation of the combined station's heat exchange network.

[0109] Based on the actual operating parameters on site, the parameters of the three cold streams and seven hot streams of the joint station were obtained, and the heat load and heat capacity flow rate of the cold and hot streams were calculated. As shown in Table 1;

[0110] Table 1 Cold and hot logistics parameters

[0111]

[0112] Then the problem table method is used to find the pinch points of the combined station heat exchange network and analyze them.

[0113] Sort the temperatures and divide the temperature zones.

[0114] The temperature zone heat balance calculation and heat cascade calculation are carried out in sequence, and the calculation results are listed in the problem table, as shown in Table 2;

[0115] Table 2 Temperature zone calculation results

[0116]

[0117]

[0118] The pinch point temperature is determined based on the information in Table 2, thereby predicting the amount of utility, that is, the minimum amount required for energy recovery, and the average pinch point temperature is obtained to be 65.4°C.

[0119] After the pinch point temperature difference is determined, the original heat exchange network should be made, such as Figure 4 As shown, the heat exchange network is optimized.

[0120] The heat exchange network diagram under the pinch point after optimization is as follows Figure 5 As shown,

[0121] The heat exchange network diagram above the optimized pinch point is as follows: Figure 6 shown.

[0122] In this embodiment, the network can recover heat to the greatest extent when the pinch point temperature difference is 10°C.

[0123] The heat exchange network shows that a 3104kW heat exchanger is installed at the wastewater outlet of the primary settling tank to exchange heat with the diluted mixed oil. Based on the utility capacity, a 624.96kW heat exchanger is installed to exchange heat with the crude oil before the dehydration heat exchanger. A 248.5kW heat exchanger is installed at the wastewater outlet of the secondary settling tank to exchange heat with the diluted mixed oil. A 1650kW heat exchanger is installed in the mixing process to exchange heat between the mixing heat transfer oil and the diluted oil. This can reduce the heat load of the heating furnace.

[0124] Before the optimization and transformation, the heating demand of the joint station was 13752.07kW. After adding 4 heat exchange units to the entire heat exchange network, the minimum utility heating load was 3930.8kW, the minimum utility cooling load was 8218.95kW, the maximum energy-saving potential could reach 5627.68kW, and the energy-saving potential reached 40.1%.

[0125] For simplicity of description, the aforementioned method embodiments are described as a series of actions. However, those skilled in the art should be aware that the present invention is not limited by the order of the actions described, as certain steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also be aware that the embodiments described in this specification are preferred embodiments, and the actions and modules involved are not necessarily required for the present invention.

[0126] It should be pointed out that in other embodiments of the present invention, the method can also be combined with one or several of the above embodiments to obtain a new method for optimizing the design of the joint station based on pinch point technology to achieve optimized transformation of the heat exchange network of the joint station.

[0127] It should be noted that, based on the method in any one or more of the above-mentioned embodiments of the present invention, the present invention also provides a storage medium, which stores program code that can implement the method described in any one or more of the above-mentioned embodiments, and when the code is executed by the operating system, it can implement the method of optimizing the joint station design based on pinch point technology as described above.

[0128] Example 2:

[0129] The methods disclosed in the embodiments of the present invention are described in detail. The methods of the present invention can be implemented using various devices or systems. Therefore, based on other aspects of the methods described in any one or more of the above embodiments, the present invention further provides a system for optimizing joint station design based on a pinch point technique. This system is configured to execute the methods for optimizing joint station design based on a pinch point technique described in any one or more of the above embodiments. Specific embodiments are provided below for detailed description.

[0130] Specifically, Figure 7FIG. 4 shows a schematic diagram of a system for optimizing joint station design based on pinch point technology provided in an embodiment of the present invention. Figure 7 As shown, the system includes:

[0131] A hot and cold logistics analysis module is configured to analyze the relevant operating parameters and energy usage of the on-site process flow of the joint station to be processed and determine the hot and cold logistics;

[0132] a logistics-related calculation module configured to calculate heat loads and heat capacity flow rates of hot logistics and cold logistics respectively;

[0133] The temperature zone and pinch point determination module is configured to divide the temperature zones based on the initial and target temperatures of each hot and cold stream, and use the problem table method to analyze each temperature zone to determine the pinch points of the joint station heat exchange network;

[0134] A pinch point temperature difference optimization module configured to perform an optimization analysis to determine a target pinch point temperature difference;

[0135] The transformation measure decision module is configured to determine the transformation measures of the joint station based on the heat exchange network, with the pinch point temperature as the limit and the set rules analysis to improve energy utilization.

[0136] Optionally, in one embodiment, the on-site process flow analyzed by the cold and hot logistics analysis module includes at least a crude oil processing process and a dilution heating process.

[0137] Furthermore, in one embodiment, the temperature zone and pinch point determination module divides the temperature zones according to the following operation:

[0138] Preliminary setting of pinch point temperature difference △T min ;

[0139] Arrange the initial and target temperatures of the hot and cold streams in ascending order, and calculate the average temperature based on the initially set pinch point temperature difference;

[0140] Arrange the average temperatures of all hot and cold logistics in ascending order and divide them into temperature zones.

[0141] Specifically, in one embodiment, the temperature zone and pinch point determination module uses the following operations to analyze each temperature zone using a problem table method to determine the pinch point of the combined station heat exchange network:

[0142] Perform heat balance calculation and heat cascade calculation for each temperature zone to determine the heat supply and heat discharge of the corresponding sub-network;

[0143] The interface of the temperature zone where the heat discharge meets the set requirements is selected as the pinch point.

[0144] Preferably, in one embodiment, the heat balance calculation is performed according to the following formula:

[0145] Ok =I k -D k (1)

[0146] D k =(∑CP cold -∑CP hot )(T k -T k+1 ) (2)

[0147] Where: O k Heat removed from the subnetwork, kW; I k Heat supplied to the subnetwork, kW; D k is the additional heat required for the kth temperature zone of the sub-network, kW; ∑CP cold is the sum of the heat capacity flow rates of the cold stream in the kth temperature zone, kW / ℃; ∑CP hot is the sum of the heat capacity flow rates of the heat flow in the kth temperature zone, kw / ℃; T k -T k+1 is the temperature interval of the kth temperature zone subnetwork; k is the number of temperature zones.

[0148] Furthermore, in an optional embodiment, the pinch temperature difference optimization module determines the total cost curve by considering heating utility volume, cooling utility volume and heat exchange area factors, and determines the pinch temperature difference corresponding to the extreme point of the total cost curve as the target pinch temperature difference.

[0149] On the other hand, in an optional embodiment, the pinch point temperature difference optimization module determines the target pinch point temperature difference through a mathematical optimization estimation method based on the hot and cold composite temperature enthalpy curve.

[0150] Preferably, in one embodiment, the transformation measure decision module is configured to perform pinch point analysis on the energy-consuming equipment of the joint station, and to make the system's minimum utility heating and minimum utility cooling consistent with previously calculated values ​​by reasonably matching the heat exchange between logistics based on the heat exchange network.

[0151] Specifically, in an optional embodiment, the transformation measure decision module determines the transformation measures of the joint station by analyzing the following rules:

[0152] The heat exchange network is divided into two parts above and below the pinch point. If the hot flow below the pinch point meets the set matching rules, a heat exchanger is set to allow the cold flow below the pinch point to exchange heat with it, and the remaining heat load of the hot flow is realized by the public cooler; if the cold flow above the pinch point meets the set matching rules, a heat exchanger is set to allow the cold flow above the pinch point to exchange heat with it, and the remaining heat load of the cold flow is realized by the public heater.

[0153] In the system for optimizing joint station design based on pinch point technology provided by the embodiment of the present invention, each module or unit structure can operate independently or in combination according to actual equipment analysis requirements and parameter calculation requirements to achieve corresponding technical effects.

[0154] It should be understood that the embodiments disclosed herein are not limited to the specific structures, processing steps, or materials disclosed herein, but should extend to equivalent substitutions of these features understood by those skilled in the relevant art. It should also be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting.

[0155] The phrase "one embodiment" mentioned in the specification means that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. Therefore, the phrase "one embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0156] Although the embodiments disclosed herein are as described above, the contents described herein are merely embodiments for facilitating understanding of the present invention and are not intended to limit the present invention. Any person skilled in the art may make any modifications and variations in the form and details of the embodiments without departing from the spirit and scope of the present invention. However, the scope of patent protection of the present invention shall remain subject to the scope defined by the appended claims.

Claims

1. A method for optimizing joint station design based on pinch point technology, characterized in that: The method comprises: Step S10: Analyze the relevant operating parameters and energy consumption of the on-site process flow of the joint station to be processed, and determine the hot logistics and cold logistics; Step S20: Calculate the heat load and heat capacity flow rate of the hot stream and the cold stream respectively; Step S30: Divide the temperature zones based on the initial temperature and target temperature of each hot stream and cold stream, and analyze each temperature zone using the problem table method to determine the pinch points of the combined station heat exchange network; Step S40: Optimize and analyze to determine the target pinch point temperature difference; Step S50: Based on the heat exchange network, the heat exchange between logistics is matched with the pinch point temperature as the boundary, and the transformation measures of the joint station are determined in combination with the set rules to improve energy utilization.

2. The method according to claim 1, characterized in that In step S10, the on-site process flow at least includes a crude oil processing process and a dilution heating process.

3. The method according to claim 1, characterized in that In step S30, the process of dividing the temperature zones includes: Preliminary setting of pinch point temperature difference △T min ; Arrange the initial and target temperatures of the hot and cold streams in ascending order, and calculate the average temperature based on the initially set pinch point temperature difference; Arrange the average temperatures of all hot and cold logistics in ascending order and divide them into temperature zones.

4. The method according to claim 1, wherein The process of analyzing each temperature zone using the problem table method to determine the pinch point of the combined station heat exchange network includes: Perform heat balance calculation and heat cascade calculation for each temperature zone to determine the heat supply and heat discharge of the corresponding sub-network; The interface of the temperature zone where the heat discharge meets the set requirements is selected as the pinch point.

5. The method according to claim 1 or 4, characterized in that Heat balance calculation is performed according to the following formula: O k =I k -D k D k =(∑CP cold -∑CP hot )(T k -T k+1 ) Where: O k Heat removed from the subnetwork, kW; I k Heat supplied to the subnetwork, kW; D k is the additional heat required for the kth temperature zone of the sub-network, kW; ∑CP cold is the sum of the heat capacity flow rates of the cold stream in the kth temperature zone, kW / ℃; ∑CP hot is the sum of the heat capacity flow rates of the heat flow in the kth temperature zone, kw / ℃; T k -T k+1 is the temperature interval of the kth temperature zone subnetwork; k is the number of temperature zones.

6. The method according to claim 1, characterized in that In step S40, a total cost curve is determined by taking into account factors such as heating utility volume, cooling utility volume and heat exchange area, and a pinch point temperature difference corresponding to an extreme point of the total cost curve is determined as a target pinch point temperature difference.

7. The method according to claim 1, characterized in that In step S40, the target pinch point temperature difference is determined by a mathematical optimization estimation method based on the hot and cold composite temperature enthalpy curve.

8. The method according to any one of claims 1 to 7, characterized in that In step S50, a pinch point analysis is performed on the energy-consuming equipment of the joint station, and the heat exchange between logistics is reasonably matched based on the heat exchange network so that the minimum utility heating and minimum utility cooling of the system are consistent with the previously calculated values.

9. The method according to claim 1, characterized in that In step S50, the transformation measures of the joint station are determined by analyzing the following rules: The heat exchange network is divided into two parts above and below the pinch point. If the hot flow below the pinch point meets the set matching rules, a heat exchanger is set to allow the cold flow below the pinch point to exchange heat with it, and the remaining heat load of the hot flow is realized by the public cooler; if the cold flow above the pinch point meets the set matching rules, a heat exchanger is set to allow the cold flow above the pinch point to exchange heat with it, and the remaining heat load of the cold flow is realized by the public heater.

10. A storage medium, characterized in that: The storage medium stores program code that can implement the method according to any one of claims 1 to 9.

11. A system for optimizing joint station design based on pinch point technology, characterized in that: The system executes the method according to any one of claims 1 to 9.

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