An oil process waste heat recovery system

Abstract

The present invention discloses an oil process waste heat recovery system, which relates to the technical field of waste heat recovery. The oil process waste heat recovery system includes an industrial water system, a heat pump system, and a wastewater recovery system. The industrial water system includes a water supply main pipeline and an oil preheating module. The water supply main pipeline has a water inlet, and the oil preheating module is connected to the crude oil pipeline. The heat pump system includes a heat pump main pipeline, a water-cooled evaporator, a compressor, and a gas cooler. The heat pump main pipeline is sequentially connected in series to the heat absorption side of the water-cooled evaporator, the compressor, and the heat release side of the gas cooler to form a closed loop. The wastewater recovery system includes a first drainage pipeline. The water supply main pipeline is sequentially connected in series to the heat absorption side of the gas cooler, the oil preheating module, and the first drainage pipeline. The first drainage pipeline passes through the heat release side of the water-cooled evaporator and forms a drainage port. The present invention realizes the recovery and reuse of the waste heat resources in the low-temperature wastewater discharged in the oil process.

Description

Technical Field

[0001] The invention relates to the technical field of waste heat recovery, and in particular to a petroleum process waste heat recovery system. Background Art

[0002] In the field of petroleum industry, there is a high demand for heat sources with a temperature of about 80~100℃. Such temperature conditions are very suitable for the crude oil preheating process of atmospheric and vacuum distillation in petroleum processes.

[0003] In the related art, the crude oil pipeline in the oil process is preheated by transporting hot water through the heating pipeline. After the crude oil pipeline is preheated, the low-temperature water with waste heat (<80°C) in the heating pipeline will be directly discharged. In addition, in some operations of the oil process, low-temperature water is used for desalination of oil raw materials, cleaning pipelines or heating and insulation. At present, the low-temperature water for these operations is taken from low-temperature water sources, which produces more difficult-to-use low-temperature wastewater (30~70°C), further exacerbating the waste of low-temperature waste heat resources. Therefore, the waste of waste heat resources in the oil process is an important problem that needs to be solved urgently. Summary of the invention

[0004] The main purpose of the present invention is to propose a waste heat recovery system for petroleum processes, aiming to recover waste heat in petroleum processes and reduce the waste of waste heat resources.

[0005] To achieve the above-mentioned purpose, the oil process waste heat recovery system proposed in the present invention includes an industrial water system, a heat pump system and a wastewater recovery system, wherein the industrial water system includes a water supply main line and an oil preheating module, wherein the water supply main line has a water inlet, and the oil preheating module is connected to the crude oil pipeline; the heat pump system includes a heat pump main line, a water-cooled evaporator, a gas-liquid separator, a compressor and a gas cooler, wherein the heat pump main line is connected in series with the heat absorption side of the water-cooled evaporator, the gas-liquid separator, the compressor and the heat release side of the gas cooler to form a closed loop; the wastewater recovery system includes a first drainage pipeline; wherein the water supply main line is connected in series with the heat absorption side of the gas cooler, the oil preheating module and the first drainage pipeline, and the first drainage pipeline passes through the heat release side of the water-cooled evaporator and forms a drainage outlet.

[0006] In one embodiment, the heat pump system further includes an air-cooled evaporator and a first heat pump branch; the air-cooled evaporator is connected to the heat pump main line through the first heat pump branch and is arranged in parallel with the water-cooled evaporator.

[0007] In one embodiment, the heat pump system further includes a recuperator and a second heat pump branch; the recuperator is disposed in the main heat pump pipeline and located between the water-cooled evaporator and the compressor, the input end of the heat absorption side of the recuperator is connected to the output end of the water-cooled evaporator, and the output end of the heat absorption side of the recuperator is connected to the input end of the compressor; the second heat pump branch passes through the recuperator and is connected to the main heat pump pipeline, so that the input end of the heat release side of the recuperator is connected to the output end of the gas cooler and the output end of the heat release side of the recuperator is connected to the input end of the water-cooled evaporator.

[0008] In one embodiment, the heat pump system further includes a bypass regulating valve and a first controller, and a second temperature sensor, a third temperature sensor and a fourth temperature sensor are further disposed on the main heat pump pipeline; the bypass regulating valve is disposed on the main heat pump pipeline and is arranged in parallel with the second heat pump branch; the second temperature sensor is connected to the input end of the compressor, the third temperature sensor is connected to the input end of the heat release side of the recuperator, and the fourth temperature sensor is connected to the input end of the heat absorption side of the recuperator; the second temperature sensor, the third temperature sensor and the fourth temperature sensor are all communicatively connected to the first controller; the first controller is connected to the bypass regulating valve and is used to control the opening degree of the bypass regulating valve.

[0009] In one embodiment, the heat pump system further includes an expansion valve, a second controller and a pressure sensor; the expansion valve is disposed on the main heat pump pipeline and the output end of the expansion valve is connected to the input end of the water-cooled evaporator; the pressure sensor is connected to the output end of the compressor, and the pressure sensor is communicatively connected to the second controller; the second controller is connected to the expansion valve and is used to control the opening degree of the expansion valve.

[0010] In one embodiment, the industrial water system further includes a water supply storage container, and the water supply storage container is disposed on the main water supply pipeline and located between the petroleum preheating module and the gas cooler; the waste water recovery system further includes a waste water storage container, and the waste water storage container is disposed on the first drain pipeline and located upstream of the water-cooled evaporator.

[0011] In one embodiment, the industrial water system further includes a water pump, a flow sensor, a first temperature sensor, and a third controller, and a sixth temperature sensor is disposed in the waste water storage container; the water pump is disposed on the water supply main pipeline and upstream of the gas cooler, the flow sensor is disposed at the output end of the water pump, and the first temperature sensor is disposed at the output end of the heat absorption side of the gas cooler; the flow sensor, the first temperature sensor, and the sixth temperature sensor are communicatively connected to the third controller; the third controller is connected to the water pump and is configured to control the rotation speed of the water pump.

[0012] In one embodiment, the industrial water system further includes a connection pipeline that connects the water supply storage container and the input end of the water pump.

[0013] In one embodiment, the industrial water system further includes a preheated water storage container, a desalination and dehydration module, a heat tracing and insulation module, a pipeline cleaning module, a first water supply branch, and a second water supply branch; the water supply main pipeline is sequentially connected to the petroleum preheating module, the preheated water storage container, the desalination and dehydration module, and the first drainage pipeline; one end of the first water supply branch is connected to the water supply main pipeline between the preheated water storage container and the desalination and dehydration module, the other end of the first water supply branch is connected to the first drainage pipeline, the first water supply branch has a heat preservation pipe section arranged along the crude oil pipeline, and the heat tracing and insulation module is disposed on the first water supply branch upstream of the heat preservation pipe section; one end of the second water supply branch is connected to the water supply main pipeline between the preheated water storage container and the desalination and dehydration module, and the other end of the second water supply branch is connected to the water supply main pipeline upstream of the petroleum preheating module.

[0014] In one embodiment, the industrial water system further includes a third water supply branch and a atmospheric and vacuum distillation module, and the waste water recovery system further includes a second drainage pipeline; the pipeline cleaning module, the third water supply branch, the second drainage pipeline, and the first drainage pipeline are sequentially connected, and the atmospheric and vacuum distillation module is disposed on the third water supply branch and is connected to the crude oil pipeline.

[0015] The waste heat recovery system for petroleum process proposed by the present invention includes an industrial water system, a heat pump system, and a wastewater recovery system. The industrial water system includes a main water supply pipeline and a petroleum preheating module. The main water supply pipeline has a water inlet, and the petroleum preheating module is connected to the crude oil pipeline. The heat pump system includes a main heat pump pipeline, a water-cooled evaporator, a compressor, and a gas cooler. The main heat pump pipeline is sequentially connected in series to the heat absorption side of the water-cooled evaporator, the compressor, and the heat release side of the gas cooler to form a closed loop. The wastewater recovery system includes a first drainage pipeline. Among them, the main water supply pipeline is sequentially connected in series to the heat absorption side of the gas cooler, the petroleum preheating module, and the first drainage pipeline. The first drainage pipeline passes through the heat release side of the water-cooled evaporator and forms a drainage outlet. The present invention collects the waste heat wastewater discharged from the industrial water system through the first drainage pipeline and transports it to the water-cooled evaporator of the heat pump system for recovery. After being compressed, heated, and upgraded by the compressor to meet the heating requirements of the petroleum process, the heat source after upgrading is then transferred to the industrial water system through the gas cooler for preheating processes such as the crude oil pipeline, realizing the recovery and utilization of the waste heat resources in the low-temperature wastewater discharged in the petroleum process. Brief Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0017] Figure 1 It is a schematic structural diagram of an embodiment of the waste heat recovery system for petroleum process provided by the present invention;

[0018] Figure 2 It is a schematic structural diagram of another embodiment of the waste heat recovery system for petroleum process provided by the present invention;

[0019] Figure 3 is Figure 2 a schematic diagram of the working fluid flow direction of the waste heat recovery system for petroleum process in CNPC.

[0020] Explanation of the reference numerals in the drawings:

[0021] 1000, waste heat recovery system for petroleum process;

[0022] 1. Industrial water system; 11. Main water supply pipeline; 11a. Inlet; 112. Petroleum preheating module; 113. Water supply storage container; 1131. Fifth temperature sensor; 1132. First water level sensor; 114. Water pump; 115. Flow sensor; 116. First temperature sensor; 117. Preheated water storage container; 118. Desalination and dehydration module; 12. Connection pipeline; 13. First water supply branch; 131. Insulated pipe section; 132. Heat tracing and insulation module; 14. Second water supply branch; 141. Pipeline cleaning module; 15. Third water supply branch; 16. Atmospheric and vacuum distillation module;

[0023] 2. Heat pump system; 21. Main heat pump pipeline; 211. Water-cooled evaporator; 212. Compressor; 213. Gas cooler; 214. Gas-liquid separator; 215. Bypass regulating valve; 216. Second temperature sensor; 217. Third temperature sensor; 218. Fourth temperature sensor; 219. Expansion valve; 220. Pressure sensor; 22. First heat pump branch; 221. Air-cooled evaporator; 23. Second heat pump branch; 231. Regenerator;

[0024] 3. Wastewater recovery system; 31. First drainage pipeline; 31a. Drainage outlet; 32. Wastewater storage container; 321. Sixth temperature sensor; 322. Second water level sensor; 33. Second drainage pipeline; 33a. Cooling water inlet;

[0025] 2000. Crude oil pipeline; 2001. Centrifugal pump.

[0026] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. Detailed implementation manners

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] It should be noted that if there are directional indications (such as up, down, left, right, front, back,...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0029] In addition, if the descriptions such as "first" and "second" are involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes scenario A, or scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] The present invention provides an oil process waste heat recovery system 1000.

[0031] Please refer to Figures 1 to 3 , in an embodiment of the present invention, the oil process waste heat recovery system 1000 includes an industrial water system 1, a heat pump system 2, and a wastewater recovery system 3. The industrial water system 1 includes a water supply main pipeline 11 and an oil preheating module 112. The water supply main pipeline 11 has a water inlet 11a, and the oil preheating module 112 is connected to the crude oil pipeline 2000; the heat pump system 2 includes a heat pump main pipeline 21, a water-cooled evaporator 211, a gas-liquid separator 214, a compressor 212, and a gas cooler 213. The heat pump main pipeline 21 is sequentially connected in series to the heat absorption side of the water-cooled evaporator 211, the gas-liquid separator 214, the compressor 212, and the heat release side of the gas cooler 213 to form a closed loop; the wastewater recovery system 3 includes a first drainage pipeline 31; wherein, the water supply main pipeline 11 is sequentially connected in series to the heat absorption side of the gas cooler 213, the oil preheating module 112, and the first drainage pipeline 31. The first drainage pipeline 31 passes through the heat release side of the water-cooled evaporator 211 and forms a drainage port 31a.

[0032] In this embodiment, the industrial water system 1 includes a main water supply pipeline 11 and an oil preheating module 112. The head end of the water supply pipeline is formed with a water inlet 11a. The main water supply pipeline 11 is responsible for introducing the water source into the industrial water system 1 and transporting it to the oil preheating module 112 in the oil process. In this process, when the main water supply pipeline 11 passes through the heat absorption side of the gas cooler 213, the water in the pipeline absorbs heat and warms up to become high-temperature hot water (90°C). The main water supply pipeline 11 transports the high-temperature hot water to the oil preheating module 112. The oil preheating module 112 is connected to the crude oil pipeline 2000 and uses the high-temperature hot water to preheat the crude oil. The crude oil in the crude oil pipeline 2000 is pumped by a centrifugal pump 2001 provided upstream of the crude oil pipeline 2000. Through preheating, the viscosity of the crude oil can be reduced, making it easier to flow, thereby reducing the resistance during the pumping process, reducing the pumping energy consumption, and also reducing the energy consumption of the next step of the oil vacuum distillation process in the oil process and reducing the input of external heat sources in the oil vacuum distillation process.

[0033] The heat pump system 2 includes a main heat pump pipeline 21, a water-cooled evaporator 211, a compressor 212, and a gas cooler 213. The main heat pump pipeline 21 is sequentially connected in series to the heat absorption side of the water-cooled evaporator 211, the compressor 212, and the heat release side of the gas cooler 213. The main heat pump pipeline 21 forms a closed loop to enable the working medium to circulate. The working medium in the water supply and drainage pipelines is water, and the working medium in the main heat pump pipeline 21 can be a refrigerant such as CO2. The water-cooled evaporator 211 is used to absorb the waste heat in the wastewater and transfer it to the working medium in the main heat pump pipeline 21. The compressor 212 compresses the working medium to increase its temperature and pressure to meet the oil preheating requirements, that is, compresses the low-temperature and low-pressure working medium flowing out of the water-cooled evaporator 211 into a high-temperature and high-pressure working medium. The gas cooler 213 transfers the heat of the high-temperature and high-pressure working medium in the main heat pump pipeline 21 to the main water supply pipeline 11 in the industrial water system 1.

[0034] The wastewater recovery system 3 includes a first drainage pipeline 31 for collecting and discharging the wastewater of the industrial water system 1. The head end of the first drainage pipeline 31 is connected to the tail end of the water supply pipeline. The tail end of the first drainage pipeline 31 has a drainage port 31a. Upstream of the drainage port 31a, the first drainage pipeline first passes through the water-cooled evaporator 211. The water-cooled evaporator 211 recovers the waste heat in the first drainage pipeline and then discharges it. Overall, the water absorbs the heat released by the working medium in the gas cooler 213, the temperature rises, the high-temperature water flows into the oil preheating module 112 to preheat the crude oil, and the preheated water is discharged through the main water supply pipeline 11 and the first drainage pipeline 31. Part of the heat is recovered by the water-cooled evaporator 211 again. In this way, the waste heat originally wasted in the wastewater is effectively recovered and utilized, improving the utilization of the wastewater waste heat and reducing energy waste.

[0035] In this embodiment, the waste heat wastewater discharged from the industrial water system 1 is collected through the first drainage pipeline and transported to the water-cooled evaporator 211 of the heat pump system 2 for recovery. After being compressed, heated, and quality-improved by the compressor 212 to meet the heating requirements of the petroleum process, it is then heat-exchanged through the gas cooler 213, and the quality-improved heat source is transferred to the industrial water system 1 for processes such as preheating the crude oil pipeline 2000, realizing the recovery and utilization of the waste heat resources in the low-temperature wastewater discharged in the petroleum process.

[0036] Further, please refer to Figures 1 to 3 , in an embodiment of the present invention, the heat pump system 2 further includes an air-cooled evaporator 221 and a first heat pump branch 22; the air-cooled evaporator 221 is connected to the heat pump main pipeline 21 through the first heat pump branch 22 and is arranged in parallel with the water-cooled evaporator 211.

[0037] In this embodiment, the air-cooled evaporator 221 serves as a supplement to the water-cooled evaporator 211, absorbs heat from the ambient air through air cooling and transfers it to the working medium in the first heat pump branch 22. The first heat pump branch 22 is connected to the heat pump main pipeline 21 and is arranged in parallel with the water-cooled evaporator 211. The air-cooled evaporator 221 can operate independently or simultaneously as needed. In this way, the heat source of the heat pump system 2 is further increased. The gas-liquid separator 214 is arranged in the heat pump main pipeline 21 and is located downstream of the air-cooled evaporator 221 and the water-cooled evaporator 211, and is also located upstream of the compressor 212. The gas-liquid separator 214 is used to ensure that the working medium entering the compressor 212 is in a gaseous state and prevent liquid working medium from entering the compressor 212 and causing damage.

[0038] The working medium evaporates into a gaseous state after absorbing heat in the air-cooled evaporator 221 or the water-cooled evaporator 211. Subsequently, the working medium enters the gas-liquid separator 214, and the possibly unevaporated liquid working medium is separated. The pure gaseous working medium is compressed by the compressor 212, and the temperature and pressure increase. The high-temperature and high-pressure working medium enters the gas cooler 213 and releases heat to the water flow in the water supply main pipeline 11. After releasing heat, the working medium continues to flow along the heat pump main pipeline 21 and finally re-enters the evaporator to complete the cycle. Through the above process, the present invention not only realizes the effective recovery and reuse of the waste heat resources in the low-temperature wastewater discharged in the petroleum process, but also further improves the heat absorption capacity and operation stability of the heat pump system 2 by adding devices such as the air-cooled evaporator 221 and the gas-liquid separator 214.

[0039] Even further, please refer to Figures 1 to 3, in an embodiment of the present invention, the heat pump system 2 further includes a recuperator 231 and a second heat pump branch 23; the recuperator 231 is arranged on the main heat pump pipeline 21 and is located between the water-cooled evaporator 211 and the compressor 212. The input end of the heat absorption side of the recuperator 231 is connected to the output end of the water-cooled evaporator 211, and the output end of the heat absorption side of the recuperator 231 is connected to the input end of the compressor 212; the second heat pump branch 23 passes through the recuperator 231 and is connected to the main heat pump pipeline 21, so that the input end of the heat release side of the recuperator 231 is connected to the output end of the gas cooler 213 and the output end of the heat release side of the recuperator 231 is connected to the input end of the water-cooled evaporator 211.

[0040] In this embodiment, the recuperator 231 recovers the heat of the working medium coming out of the gas cooler 213 and is used to preheat the working medium about to enter the compressor 212, thereby reducing the energy consumption of the compressor 212 and improving the overall energy efficiency of the system.

[0041] The working medium evaporates into a gaseous state after absorbing heat in the water-cooled evaporator 211 or the air-cooled evaporator 221. The gaseous working medium enters the heat absorption side of the recuperator 231 and is preheated by the high-temperature working medium coming out of the compressor 212. The preheated gaseous working medium enters the compressor 212 and is compressed into a high-temperature and high-pressure state. The high-temperature and high-pressure working medium enters the gas cooler 213 and releases heat to the main water supply pipeline 11. The working medium after heat release further cools down through the heat release side of the recuperator 231 and finally re-enters the water-cooled evaporator 211 or the air-cooled evaporator 221 to complete the cycle. The working medium cooled by the recuperator 231 is more conducive to absorbing heat from the water-cooled evaporator 211 or the air-cooled evaporator 221.

[0042] In this embodiment, by adding the recuperator 231 and the second heat pump branch 23, the heat energy utilization efficiency of the heat pump system 2 is further optimized. The recuperator 231 realizes the preheating of the working medium before and after entering the compressor 212, reduces the power consumption of the compressor 212, and at the same time improves the overall energy efficiency ratio of the system, making the heat pump system 2 more efficient and energy-saving when recovering the waste heat of the petroleum process.

[0043] Please refer to Figures 1 to 3, in an embodiment of the present invention, the heat pump system 2 further includes a bypass regulating valve 215 and a first controller. A second temperature sensor 216, a third temperature sensor 217, and a fourth temperature sensor 218 are further provided on the main heat pump pipeline 21; the bypass regulating valve 215 is provided on the main heat pump pipeline 21 and is arranged in parallel with the second heat pump branch 23; the second temperature sensor 216 is connected to the input end of the compressor 212, the third temperature sensor 217 is connected to the input end of the heat release side of the regenerator 231, and the fourth temperature sensor 218 is connected to the input end of the heat absorption side of the regenerator 231; the second temperature sensor 216, the third temperature sensor 217, and the fourth temperature sensor 218 are all communicatively connected to the first controller; the first controller is connected to the bypass regulating valve 215 and is used to control the opening degree of the bypass regulating valve 215.

[0044] In this embodiment, the bypass regulating valve 215 is provided on the main heat pump pipeline 21 and is arranged in parallel with the second heat pump branch 23, and is used to adjust the flow rate of the working medium flowing through the regenerator 231, so as to adjust the heat regeneration rate (Rh) of the regenerator 231. The bypass regulating valve 215 can adopt an electric valve or a solenoid valve, etc. The first controller can be directly communicatively connected or remotely communicatively connected to the bypass regulating valve 215, the second temperature sensor 216, the third temperature sensor 217, and the fourth temperature sensor 218 through a circuit respectively. The first controller adjusts the opening degree of the bypass regulating valve 215 in real time according to the feedback data of each temperature sensor to optimize the heat regeneration rate (Rh) of the regenerator 231 and ensure that the system operates in the best state. The first controller can adopt an intelligent control unit based on a microprocessor or a PLC or adopt a PID controller, etc.

[0045] A bypass regulating valve 215 is connected in parallel to the regenerator 231. During operation, the first controller controls the working medium flow rate of the regenerator 231 by adjusting the opening degree of the bypass regulating valve 215, thereby regulating the local pressure and the regeneration rate (Rh) of the regenerator 231. It should be noted that the regulation of the regeneration rate (Rh) aims to increase the coefficient of performance (COP) by increasing the regeneration rate. Specifically, the calculation of the regeneration rate (Rh) is related to multiple key variables, including the suction temperature T216 of the compressor 212 (measured by the second temperature sensor 216), the inlet temperature T218 of the heat absorption side of the regenerator 231 (measured by the fourth temperature sensor 218), the inlet temperature T217 of the heat release side of the regenerator 231 (measured by the third temperature sensor 217), the ambient temperature (T_air), and the waste heat wastewater temperature (T_flu), etc. The regeneration rate of the heat pump system 2 is calculated by constructing an association model between these variables T216, T217, T218, T_air, and T_flu and the regeneration rate (Rh), and then the opening degree of the bypass regulating valve 215 is controlled, and the regeneration rate at different opening degrees is calculated to simulate the feedback regulation of the bypass regulating valve 215 on the regeneration rate (Rh). The opening degree range of the bypass regulating valve 215 is 0 - 100. During operation, based on the actual operating condition values under the current operating condition, multiple initial opening degrees such as 10, 20, 30, etc. are set. In order to more accurately simulate the feedback regulation of the bypass regulating valve 215 on the regeneration rate (Rh), initial opening degrees with smaller graduations can also be used, such as 5, 10, 15, 20, etc. The second temperature sensor 216, the third temperature sensor 217, and the fourth temperature sensor 218 respectively measure the suction temperature (T216) of the compressor 212, the inlet temperature (T217) of the heat release side of the regenerator 231, and the inlet temperature of the low-pressure side (T218). These data are jointly used as the input parameters of the first controller. The first controller calculates the respective regeneration rates (Rh) at different opening degrees of the bypass regulating valve 215 according to the temperature difference and the set target, and compares to obtain the opening degree of the bypass regulating valve 215 corresponding to the optimal regeneration rate (Rh), that is, the required opening degree. Based on the above experimental tests, combined with the data obtained from the simulation, the relevant association formula of the regeneration rate is fitted as follows:

[0046] Rh = f(T27, T28, T29, T_air, T_flu)

[0047] In the above relational expression, Rh represents the actual regeneration rate at a certain opening degree. Through the relational expression, the regeneration rate (Rh) of the regenerator 231 can be accurately calculated. Then, the opening degree of the bypass regulating valve 215 is used as a control variable, and by adjusting the opening degree of the bypass regulating valve 215, the working fluid flow rate of the regenerator 231 is adjusted to affect the regeneration rate (Rh). Specifically, as the ambient temperature or the temperature of the waste heat wastewater changes, the first controller measures the current operating state of the heat pump system 2 through a real-time feedback mechanism, and continuously adjusts the opening degree of the bypass regulating valve 215 according to the changing trends of the actual regeneration rate (Rh) and the coefficient of performance (COP), ensuring that the regeneration rate (Rh) of the regenerator 231 is within the optimal range and tends to the optimal value, so as to ensure that the working fluid can effectively exchange heat in the regenerator 231, thereby improving the overall energy efficiency of the system.

[0048] It should be noted that in this system, the regeneration rate (Rh) is not the higher the better. Although increasing the regeneration rate (Rh) can increase the temperature of the working fluid before entering the compressor 212, thereby reducing the compression work of the compressor 212 and improving the energy efficiency of the system, an excessively high regeneration rate (Rh) will also cause the exhaust temperature of the compressor 212 to be too high, which may exceed the allowable operating temperature of the compressor 212, affecting the life and safety of the compressor 212. Therefore, the regeneration rate (Rh) needs to be within a suitable range to ensure the overall performance and energy efficiency of the system. The optimal regeneration rate (Rh) should be determined by comprehensively considering multiple factors such as the working conditions of the compressor 212, the system pressure, the performance of the evaporator, and the energy utilization efficiency. Through methods such as experimental testing, simulation, and theoretical calculation, this optimal regeneration rate (Rh) can be found, and then the first controller controls the bypass regulating valve 215 to reach the opening degree corresponding to the optimal regeneration rate (Rh), so that the system can achieve the highest heat recovery rate on the premise of ensuring safe and stable operation.

[0049] In this embodiment, by setting the bypass regulating valve 215 and the first controller, the efficient operation of the regenerator 231 can be maintained under different working conditions, the waste heat resources in the petroleum process can be maximally recovered, the accurate control of the regeneration rate (Rh) of the regenerator 231 is realized, and the energy efficiency and stability of the heat pump system 2 are further improved.

[0050] Please refer to Figures 1 to 3 , in an embodiment of the present invention, the heat pump system 2 further includes an expansion valve 219, a second controller, and a pressure sensor 220; the expansion valve 219 is provided on the heat pump main pipeline 21 and the output end of the expansion valve 219 is connected to the input end of the water-cooled evaporator 211; the pressure sensor 220 is connected to the output end of the compressor 212, and the pressure sensor 220 is communicatively connected to the second controller; the second controller is connected to the expansion valve 219 and is used to control the opening degree of the expansion valve 219 to adjust the exhaust pressure of the compressor 212.

[0051] In this embodiment, the functions of the expansion valve 219 are mainly reflected in the following two aspects: Throttling and pressure reduction: The main function of the expansion valve 219 is to reduce the pressure of the refrigerant. After the high-pressure refrigerant coming out of the compressor 212 passes through the expansion valve 219, the pressure drops rapidly, enabling it to absorb heat when entering the water-cooled evaporator 211 or the air-cooled evaporator 221. Flow control: The expansion valve 219 can control the refrigerant flow rate entering the water-cooled evaporator 211 or the air-cooled evaporator 221, thereby affecting the evaporation temperature and pressure in the evaporator, and further affecting the intake pressure and exhaust pressure of the compressor 212. Generally, for the compressor 212, a lower exhaust pressure will result in a lower coefficient of performance (COP value), while a higher exhaust pressure will result in a higher COP value. Therefore, by increasing the exhaust pressure of the compressor 212, the COP value of the system can be increased, improving the energy utilization efficiency. However, the exhaust pressure of the compressor 212 will also affect the stability of the system. An excessively high exhaust pressure will cause the compressor 212 to be overloaded, while an excessively low exhaust pressure will cause the compressor 212 to operate unstably. Therefore, by controlling the exhaust pressure of the compressor 212, the energy efficiency ratio and COP value of the heat pump system 2 can be increased on the premise of stable operation.

[0052] The second controller receives the data from the pressure sensor 220 and analyzes it to adjust the opening degree of the expansion valve 219, thereby indirectly affecting the exhaust pressure of the compressor 212 to achieve the optimal exhaust pressure and improve the system performance. For example, as the opening degree of the expansion increases, the flow rate through the expansion valve 219 increases, and the pressure in the water-cooled evaporator 211 or the air-cooled evaporator 221 also gradually increases. Therefore, the intake pressure of the downstream compressor 212 will gradually increase, resulting in a decrease in the compression ratio, and the exhaust pressure and exhaust temperature of the compressor 212 will ultimately decrease. The second controller can adopt an intelligent control unit based on a microprocessor or PLC or adopt a PID controller, etc., and correspondingly adopt an electronic expansion valve 219. In this embodiment, preferably, carbon dioxide is used as the working medium of the heat pump system 2, and a PID controller is used as the second controller.

[0053] The calculation of the exhaust pressure of the compressor 212 is mainly related to the ambient temperature (T_air), the temperature of the waste heat and wastewater (T_flu), and the phase state (X) of the carbon dioxide working medium. By establishing a correlation model between the exhaust pressure and these variable parameters. Experiments are carried out on different combinations of the phase state of carbon dioxide, ambient temperature, and waste heat and wastewater temperature, and the exhaust pressure data (P_out) during the corresponding system operation are recorded through the pressure sensor 220. And by using the data fitting technology, the following correlation formula is obtained:

[0054] P_out = f(X, T_air, T_flu)

[0055] Determine the optimal exhaust pressure during the stable operation of the heat pump system 2 according to the experiment and the above correlation. In the actual working conditions, the optimization control of the exhaust pressure adopts the method of precisely adjusting the electronic expansion valve 219 by the second controller. The second controller calculates and outputs parameters based on the deviation between the set optimal exhaust pressure and the actual exhaust pressure, and dynamically adjusts the opening degree of the expansion valve 219, so that the actual exhaust pressure gradually approaches and stabilizes at the optimal exhaust pressure, thereby ensuring that the heat pump system 2 operates at the set optimal exhaust pressure. The opening degree of the expansion valve 219 can be dynamically adjusted between 0 and 100. During the operation of the heat pump system 2, the optimal exhaust pressure value is calculated in real time through the correlation according to the current operating conditions, and used as the set parameter of the second controller. When the heat pump system 2 is operating, the pressure sensor 220 is used to measure the exhaust pressure of the compressor 212 in real time, and this value is used as the input parameter of the second controller. If there is a deviation between this input parameter and the set parameter, and the deviation value is greater than the set accuracy value, then the difference between the two is used as the input parameter and input into the second controller. The second controller calculates the adjustment amount according to the input parameter. After adding the adjustment amount to the set opening degree value of the expansion valve 219, it is input into the electronic expansion valve 219 to adjust the opening degree value of the expansion valve 219, thereby changing the exhaust pressure of the compressor 212. With the adjustment of the second controller, the exhaust pressure will get closer and closer to the set parameter until the absolute value of the deviation between the two is less than the set accuracy value, which proves that the exhaust pressure reaches the optimal exhaust pressure value under the control and adjustment of the second controller.

[0056] Specifically, the second controller uses the difference method for calculation, and the expansion valve 219 dynamically adjusts the opening degree The calculation formula is:

[0057]

[0058] Where is the difference between the actual exhaust pressure and the set exhaust pressure, n is the number of operations, , and are the proportional adjustment coefficient, integral adjustment coefficient and differential adjustment coefficient respectively. Taking the current operating conditions as the condition, the optimal exhaust pressure of the compressor 212 in the heat pump system 2 is calculated through experimental tests and the exhaust pressure correlation. The second controller adjusts the opening degree of the expansion valve 219 in real time, so that the real-time exhaust pressure of the compressor 212 under this condition gradually reaches the optimal exhaust pressure.

[0059] Please refer to Figures 1 to 3, in an embodiment of the present invention, the industrial water system 1 further includes a water supply storage container 113, which is arranged on the water supply main pipeline 11 and located between the petroleum preheating module 112 and the gas cooler 213; the wastewater recovery system 3 further includes a wastewater storage container 32, which is arranged on the first drainage pipeline 31 and located upstream of the water-cooled evaporator 211.

[0060] In this embodiment, considering that the industrial water system 1 may require different amounts of water under different working conditions, a water supply storage container 113 is arranged on the water supply main pipeline 11 to flexibly adjust the water supply flow rate to meet the requirements of different working conditions. Correspondingly, the wastewater storage container 32 is used to collect and store the waste heat wastewater discharged from the high and medium temperature petroleum process links such as atmospheric and vacuum distillation and desalination and dehydration. The wastewater discharge volume may also be unstable in flow rate under different working conditions. In order to avoid insufficient heat exchange in the liquid-cooled evaporator when the wastewater discharge volume is large, resulting in heat loss, and the recovered heat is not enough to supply industrial heat when the wastewater discharge volume is small, a wastewater storage container 32 is arranged on the first drainage pipeline 31. The water supply storage container 113 and the wastewater storage container 32 can be constructed of corrosion-resistant materials, such as building water tanks or storage tanks with stainless steel materials.

[0061] The water supply storage container 113 can store a certain amount of water to regulate the water supply flow rate and pressure, which can ensure stable water supply under different demands of the system, and can also avoid pressure fluctuations or water supply falling short of water demand caused by instantaneous large water consumption. In addition, when the water supply system fails or the water source is temporarily interrupted, the water in the water supply storage container 113 can be used as an emergency water source to ensure the normal operation of the system for a short time. The wastewater storage container 32 can collect and store wastewater, regulate the flow rate and pressure of wastewater discharge, and can avoid insufficient heat exchange in the liquid-cooled evaporator caused by too fast wastewater discharge, resulting in heat loss. And the wastewater storage container 32 can also temporarily store wastewater when the wastewater treatment system fails, avoiding direct discharge and causing energy waste. The water supply storage container 113 and the wastewater storage container 32, as buffer zones, can absorb the flow rate and pressure fluctuations in the system and provide more stable operating conditions.

[0062] Further, a sixth temperature sensor 321 and a second water level sensor 322 may be provided in the wastewater storage container 32 to detect the temperature and water storage volume of the water in the wastewater storage container 32. When the heat pump system 2 is operating, if the second water level sensor 322 in the wastewater storage container 32 measures that the industrial wastewater storage volume is less than the set value or the sixth temperature sensor 321 therein measures that the industrial wastewater storage temperature is less than the set value, the heat pump system 2 may adopt air source heating, the air-cooled evaporator 221 operates, and the water-cooled evaporator 211 stops operating, and the wastewater storage container 32 stops draining water; otherwise, the heat pump system 2 may adopt waste heat wastewater heating, the water-cooled evaporator 211 operates, the air-cooled evaporator 221 stops operating, and the wastewater storage container 32 starts draining water. In this way, by automatically switching the heat supply source of the heat pump system 2 according to the water temperature and water volume in the wastewater storage container 32, the waste heat can be preferentially used when there is waste heat available, thereby reducing the dependence on electric energy and improving the overall energy efficiency of the system. By real-time monitoring of the water temperature and water volume of the wastewater storage container 32, the efficiency decline or failure of the heat pump system 2 caused by too low water level or too low water temperature can be avoided, improving the stability and reliability of the system. The system can flexibly switch the heat supply source according to the actual working conditions to adapt to the heat supply requirements under different conditions, enhancing the adaptability and flexibility of the system.

[0063] Further, please refer to Figures 1 to 3 , in an embodiment of the present invention, the industrial water system 1 further includes a water pump 114, a flow sensor 115, a first temperature sensor 116, and a third controller, and a sixth temperature sensor 321 is provided in the wastewater storage container 32; the water pump 114 is provided on the water supply main pipeline 11 and upstream of the gas cooler 213, the flow sensor 115 is provided at the output end of the water pump 114, and the first temperature sensor 116 is provided at the output end of the heat absorption side of the gas cooler 213; the flow sensor 115, the first temperature sensor 116, and the sixth temperature sensor 321 are communicatively connected to the third controller; the third controller is connected to the water pump 114 and is used to control the rotation speed of the water pump 114.

[0064] In this embodiment, in addition to providing the power to pump the working medium (water) into the water supply main pipeline 11, the water pump 114 functions to adjust the outlet water temperature of the heat absorption side of the gas cooler 213. The third controller can adjust the rotation speed of the water pump 114 to control the water flow rate in the water supply main pipeline 11, that is, the water flow rate in the gas cooler 213. When the water flow rate increases, the heat exchange efficiency of the gas cooler 213 remains unchanged, and the greater the flow rate, the smaller the heat absorption per unit volume of water, resulting in a decrease in the outlet water temperature. When the water flow rate decreases, the heat exchange efficiency of the gas cooler 213 remains unchanged, and the smaller the flow rate, the greater the heat absorption per unit volume of water, resulting in an increase in the outlet water temperature.

[0065] Specifically, to meet the temperature requirements for preheating the crude oil pipeline 2000 in the petroleum process, the water temperature at the outlet of the gas cooler 213 is adaptively adjusted so that the temperature of the hot water stored in the water supply storage container 113 after heat exchange in the gas cooler 213 in the main water supply pipeline 11 is constantly 90°C. The water temperature at the outlet of the gas cooler 213 (T_out) is related to the cooling water flow rate (F_flu), the ambient temperature (T_air), the temperature of the surplus heat source (T_flu), etc. To control the water temperature at the outlet of the gas cooler 213 to meet the petroleum preheating requirements as the goal, a correlation model between the outlet temperature and these variable parameters is built, experiments are carried out on different operating condition combinations, the water temperature data at the outlet of the gas cooler 213 when the corresponding system operates stably are recorded, and based on this, combined with the data obtained from the simulation, the correlation formula for the optimal outlet water temperature is fitted, and its coupling correlation formula is:

[0066] T_ out=f(F_flu, T_air, T_flu)

[0067] The optimal adjustment of the water temperature at the heat absorption side of the gas cooler 213 is also based on the adjustment strategy of the PID controller, that is, the third controller can adopt the PID controller, but here the adjustment object is the rotational speed of the water pump 114. During the operation of the industrial water system 1, according to the optimal actual required operating conditions, the set value T_out of the water temperature at the outlet of the gas cooler 213 is 90°C, and it is used as the set value of the third controller for the system operation target. The first temperature sensor 116 is responsible for measuring the water temperature (T_out) at the outlet of the gas cooler 213, and the difference between it and the set value is used as the input parameter of the third controller. If there is a deviation between the actual outlet water temperature in the cycle and the set value, and the deviation value is greater than the set accuracy value, then the difference between the two is used as the input parameter and input into the third controller. The third controller calculates the adjustment amount according to the input parameter. After adding the adjustment amount to the set rotational speed value of the water pump 114, it is input into the water pump 114 to adjust the rotational speed of the water pump, change the cooling water flow rate (F_flu), and then change the outlet water temperature at the heat absorption side of the gas cooler 213. With the adjustment of the third controller, the outlet water temperature will get closer and closer to the initial set value until the absolute value of the deviation between the two is less than the set value, which proves that the outlet water temperature reaches the set value of 90°C under the control and adjustment of the third controller;

[0068] The third controller calculates by the difference method, and the water pump 114 dynamically adjusts the rotational speed The calculation formula is:

[0069]

[0070] Among them, is the difference between the actual drainage temperature and the set drainage temperature, n is the number of operations, is the output value of the PID controller at the nth operation, , and are the proportional adjustment coefficient, the integral adjustment coefficient, and the derivative adjustment coefficient respectively. 6000 is the initial speed of the water pump 114 in this embodiment, which can be replaced according to the initial speed of the actually used water pump.

[0071] Furthermore, please refer to Figures 1 to 3 , in an embodiment of the present invention, the industrial water system 1 further includes a connection pipeline 12, and the connection pipeline 12 connects the water supply storage container 113 and the input end of the water pump 114.

[0072] In this embodiment, the water supply storage container 113 is a constant temperature water tank or a constant temperature water storage tank to ensure that high-temperature hot water can be provided for industrial water in real time. The main water supply pipeline 11 is connected to the upper part of the constant temperature water tank for inputting high-temperature hot water into the constant temperature water tank and outputting high-temperature hot water to the petroleum preheating module 112, etc. One end of the connection pipeline 12 is connected to the lower part of the constant temperature water tank, and the other end is connected to the input end of the water pump 114 for re-inputting the cooled water at the lower part of the constant temperature water tank into the water pump 114, and then passing through the gas cooler 213 again, absorbing heat in the gas cooler 213 and returning to the constant temperature water tank to achieve the constant temperature effect.

[0073] For the convenience of control, solenoid valves can be respectively arranged at the water inlet 11a of the main water supply pipeline 11, on the connection pipeline 12, and on the main water supply pipeline at the output end of the water supply storage container 113. A fifth temperature sensor 1131 and a first water level sensor 1132 are arranged in the water supply storage container 113 to monitor the temperature and water storage capacity of the water inside the water supply storage container 113. If the fifth temperature sensor 1131 in the water supply storage container 113 detects that the hot water temperature drops, the solenoid valve on the connection pipeline 12 is opened, and the cooled hot water reaches the gas cooler 213 through the water pump 114 and is reheated to 90°C and then returns to the water supply storage container 113. Or if the first water level sensor 1132 detects that the water storage capacity in the water supply storage container 113 is lower than the set value, the solenoid valve at the water inlet 11a is opened, and the cold water provided by the water supply source is heated to 90°C after passing through the water pump 114 and the gas cooler 213 and then stored in the water supply storage container 113; if the fifth temperature sensor 1131 in the water supply storage container 113 detects that the hot water is 90°C and the first water level sensor 1132 detects that the water storage capacity exceeds, the solenoid valve on the connection pipeline 12 and the solenoid valve at the water inlet 11a are closed.

[0074] Furthermore, please refer to Figures 1 to 3, in an embodiment of the present invention, the industrial water system 1 further includes a preheated water storage container 117, a desalination and dehydration module 118, a tracing and heat preservation module 132, a pipeline cleaning module 141, a first water supply branch 13, and a second water supply branch 14; the water supply main pipeline 11 is sequentially connected to the petroleum preheating module 112, the preheated water storage container 117, the desalination and dehydration module 118, and the first drainage pipeline 31; one end of the first water supply branch 13 is connected to the water supply main pipeline 11 between the preheated water storage container 117 and the desalination and dehydration module 118, the other end of the first water supply branch 13 is connected to the first drainage pipeline 31, the first water supply branch 13 has a heat preservation pipe section 131 arranged along the crude oil pipeline 2000, and the tracing and heat preservation module 132 is arranged on the first water supply branch 13 upstream of the heat preservation pipe section 131; one end of the second water supply branch 14 is connected to the water supply main pipeline 11 between the preheated water storage container 117 and the desalination and dehydration module 118, and the other end of the second water supply branch 14 is connected to the water supply main pipeline 11 upstream of the petroleum preheating module 112.

[0075] In this embodiment, the preheated water storage container 117 is used to store the preheated water output from the petroleum preheating module 112 for preheating the crude oil pipeline 2000. This part of the hot water still has relatively high waste heat and can be used for the desalination and dehydration module 118, the tracing and heat preservation module 132, and the pipeline cleaning module 141. The preheated water storage container 117 can store water for flexible regulation to supply water to the desalination and dehydration module 118, the tracing and heat preservation module 132, and the pipeline cleaning module 141 according to different working conditions. The desalination and dehydration module 118 is used to remove the salt and water in the crude oil to improve the quality of the crude oil and the efficiency of subsequent petroleum processes. The preheated water storage container 117 transports the surplus hot water to the desalination and dehydration module 118 to meet part of the heating demand, reduce the energy input of the desalination and dehydration module 118, and save the cost of the desalination and dehydration process. The tracing and heat preservation module 132 is arranged upstream of the heat preservation pipe section 131 of the first water supply branch 13 and is used to perform tracing and heat preservation on the transported working medium to prevent the system operation from being affected due to temperature drop during transportation. The heat preservation pipe section 131 extends along the crude oil pipeline 2000 and can continuously supply heat to the crude oil pipeline 2000 to achieve the heat preservation effect, ensuring the fluidity and stability of the petroleum during transportation. The pipeline cleaning module 141 cleans the pipelines in the petroleum preheating module 112 and the desalination and dehydration module 118 respectively to remove the residual harmful substances and sediments in the pipelines.

[0076] Further, please refer to Figures 1 to 3, in an embodiment of the present invention, the industrial water system 1 further includes a third water supply branch 15 and a atmospheric and vacuum distillation module 16, and the wastewater recovery system 3 further includes a second drainage pipeline 33; the pipeline cleaning module 141, the third water supply branch 15, the second drainage pipeline 33 and the first drainage pipeline 31 are connected in sequence, and the atmospheric and vacuum distillation module 16 is arranged on the third water supply branch 15 and connected to the crude oil pipeline 2000.

[0077] In this embodiment, the atmospheric and vacuum distillation module 16 is used for preliminary separation and refining of crude oil. The hot wastewater discharged in the atmospheric and vacuum distillation process has a temperature of 80-100°C, and this part of the hot water is collected through the second drainage pipeline 33 and finally flows into the first drainage pipeline 31. The hot wastewater discharged from the desalination and dehydration module 118, the pipeline cleaning module 141, and the heat tracing and insulation module 132 has a temperature of 35-70°C. Part of it is directly collected through the first drainage pipeline 31, and the other part is input to the atmospheric and vacuum distillation module 16 for cleaning during the cleaning stage through the pipeline cleaning module 141 and the third water supply branch 15, and is collected through the second drainage pipeline 33. In this way, the waste heat recovery of the atmospheric and vacuum distillation module 16 is realized, and the waste heat wastewater output by the petroleum preheating module 112 is used for cleaning the atmospheric and vacuum distillation module 16, reducing heat energy waste and realizing the reuse of water resources.

[0078] When the petroleum process starts and runs, the petroleum preheating module 112, the desalination and dehydration module 118, the heat tracing and insulation module 132, and the atmospheric and vacuum distillation module 16 operate. Petroleum is sent into the petroleum preheating module 112 by the centrifugal pump 2001. The hot water in the constant temperature water tank enters the petroleum preheating module 112 through the main water supply pipeline 11. The hot water releases heat and exchanges heat with the petroleum. The water after heat exchange flows into the preheated water storage container 117 for storage. A part of the water in the preheated water storage container 117 enters the desalination and dehydration module 118 to assist in removing the salt and water in the preheated petroleum. Another part of the water is transported through the heat tracing and insulation module 132 to the crude oil pipeline 2000 between the petroleum preheating module 112 and the desalination and dehydration module 118 for heat preservation treatment to ensure the fluidity and stability of the petroleum during transportation. These two parts of water flow into the waste water storage container 32 after completing desalination, dehydration, heat tracing and insulation; The petroleum discharged from the desalination and dehydration module 118 enters the atmospheric and vacuum distillation module 16 for high-temperature distillation treatment. At the same time, cooling water is input through the cooling water inlet 33a to enter some parts of the distillation tower in the atmospheric and vacuum distillation module 16 to control the temperature and prevent overheating. The petroleum discharged from this module flows to the next petroleum process link, while the discharged water also flows into the waste water storage container 32; When the petroleum process ends, the pipeline cleaning module 141 operates. The remaining water in the preheated water storage container 117 all enters the pipeline cleaning module 141 and is divided into three parts to clean the pipelines in the petroleum preheating module 112, the desalination and dehydration module 118, and the atmospheric and vacuum distillation module 16 respectively, removing the harmful substances and sediments remaining in the pipelines. The water discharged after cleaning the three modules all flows into the waste water storage container 32.

[0079] The above is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. An oil process waste heat recovery system, characterized in that, The described oil process waste heat recovery system includes: An industrial water system (1), where the industrial water system (1) includes a main water supply pipeline (11) and an oil preheating module (112). The main water supply pipeline (11) has a water inlet (11a), and the oil preheating module (112) is connected to the crude oil pipeline; A heat pump system (2), where the heat pump system (2) includes a main heat pump pipeline (21), a water-cooled evaporator (211), a gas-liquid separator (214), a compressor (212), and a gas cooler (213). The main heat pump pipeline (21) is sequentially connected in series to the heat absorption side of the water-cooled evaporator (211), the gas-liquid separator (214), the compressor (212), and the heat release side of the gas cooler (213) to form a closed loop; and A wastewater recovery system (3), where the wastewater recovery system (3) includes a first drainage pipeline (31); Wherein, the main water supply pipeline (11) is sequentially connected in series to the heat absorption side of the gas cooler (213), the oil preheating module (112), and the first drainage pipeline (31). The first drainage pipeline (31) passes through the heat release side of the water-cooled evaporator (211) and forms a drainage port (31a); The industrial water system (1) further includes a preheated water storage container (117), a desalination and dehydration module (118), a heat tracing and insulation module (132), a pipeline cleaning module (141), a first water supply branch (13), and a second water supply branch (14); The main water supply pipeline (11) is sequentially connected to the oil preheating module (112), the preheated water storage container (117), the desalination and dehydration module (118), and the first drainage pipeline (31); One end of the first water supply branch (13) is connected to the main water supply pipeline (11) between the preheated water storage container (117) and the desalination and dehydration module (118). The other end of the first water supply branch (13) is connected to the first drainage pipeline (31). The first water supply branch (13) has a heat-insulated pipe section (131) arranged along the crude oil pipeline, and the heat tracing and insulation module (132) is provided on the first water supply branch (13) upstream of the heat-insulated pipe section (131); One end of the second water supply branch (14) is connected to the main water supply pipeline (11) between the preheated water storage container (117) and the desalination and dehydration module (118). The other end of the second water supply branch (14) is connected to the main water supply pipeline (11) upstream of the oil preheating module (112).

2. The waste heat recovery system for petroleum process as claimed in claim 1, wherein, The heat pump system (2) further includes an air-cooled evaporator (221) and a first heat pump branch (22); The air-cooled evaporator (221) is connected to the main heat pump pipeline (21) through the first heat pump branch (22) and is arranged in parallel with the water-cooled evaporator (211).

3. The waste heat recovery system for oil process as claimed in claim 1, wherein, The heat pump system (2) further includes a regenerator (231) and a second heat pump branch (23); The regenerator (231) is arranged in the main heat pump pipeline (21) and is located between the water-cooled evaporator (211) and the compressor (212). The input end of the heat absorption side of the regenerator (231) is connected to the output end of the water-cooled evaporator (211), and the output end of the heat absorption side of the regenerator (231) is connected to the input end of the compressor (212). The second heat pump branch (23) passes through the regenerator (231) and is connected to the main heat pump pipeline (21), so that the input end of the heat release side of the regenerator (231) is connected to the output end of the gas cooler (213), and the output end of the heat release side of the regenerator (231) is connected to the input end of the water-cooled evaporator (211).

4. The waste heat recovery system for oil process according to claim 3, wherein, The heat pump system (2) further includes a bypass regulating valve (215) and a first controller. A second temperature sensor (216), a third temperature sensor (217), and a fourth temperature sensor (218) are also arranged on the main heat pump pipeline (21). The bypass regulating valve (215) is arranged in the main heat pump pipeline (21) and is arranged in parallel with the second heat pump branch (23). The second temperature sensor (216) is connected to the input end of the compressor (212), the third temperature sensor (217) is connected to the input end of the heat release side of the regenerator (231), and the fourth temperature sensor (218) is connected to the input end of the heat absorption side of the regenerator (231). The second temperature sensor (216), the third temperature sensor (217), and the fourth temperature sensor (218) are all communicatively connected to the first controller. The first controller is connected to the bypass regulating valve (215) and is used to control the opening degree of the bypass regulating valve (215).

5. The waste heat recovery system for petroleum process as claimed in claim 1, wherein, The heat pump system (2) further includes an expansion valve (219), a second controller, and a pressure sensor (220). The expansion valve (219) is arranged in the main heat pump pipeline (21), and the output end of the expansion valve (219) is connected to the input end of the water-cooled evaporator (211). The pressure sensor (220) is connected to the output end of the compressor (212), and the pressure sensor (220) is communicatively connected to the second controller. The second controller is connected to the expansion valve (219) and is used to control the opening degree of the expansion valve (219).

6. The waste heat recovery system for the petroleum process according to claim 1, wherein, The industrial water system (1) further includes a water supply storage container (113). The water supply storage container (113) is arranged in the main water supply pipeline (11) and is located between the petroleum preheating module (112) and the gas cooler (213). The wastewater recovery system (3) further includes a wastewater storage container (32). The wastewater storage container (32) is arranged on the first drainage pipeline (31) and is located upstream of the water-cooled evaporator (211).

7. The waste heat recovery system for the petroleum process according to claim 6, wherein The industrial water system (1) further includes a water pump (114), a flow sensor (115), a first temperature sensor (116), and a third controller. A sixth temperature sensor is provided in the waste water storage container (32). The water pump (114) is provided on the water supply main pipeline (11) and upstream of the gas cooler (213). The flow sensor (115) is provided at the output end of the water pump (114). The first temperature sensor (116) is provided at the output end of the heat absorption side of the gas cooler (213). The flow sensor (115), the first temperature sensor (116), and the sixth temperature sensor are communicatively connected to the third controller. The third controller is connected to the water pump (114) and is used to control the rotation speed of the water pump (114).

8. The waste heat recovery system for oil process as claimed in claim 7, wherein, The industrial water system (1) further includes a connection pipeline (12) that connects the water supply storage container (113) to the input end of the water pump (114).

9. The waste heat recovery system for the petroleum process according to claim 1, characterized in that, The industrial water system (1) further includes a third water supply branch (15) and a vacuum distillation module (16). The waste water recovery system (3) further includes a second drainage pipeline (33). The pipeline cleaning module (141), the third water supply branch (15), the second drainage pipeline (33), and the first drainage pipeline (31) are connected in sequence. The vacuum distillation module (16) is provided on the third water supply branch (15) and is connected to the crude oil pipeline.

Images