Pump control method and system for tower water heat recovery heating based on digital twinning

Abstract

This invention discloses a heat pump control method and system for tower water heat recovery heating based on digital twins. A magnetic levitation heat pump absorbs heat from the tower water system and the circulating water side of the production line through an evaporator, and releases heat to heat the water tank through a condenser and plate heat exchanger. The method further includes the following steps: a magnetic levitation heat pump unit operating in the waste heat recovery process of the tower water circulation system under multiple operating conditions, enabling heat transfer within the temperature range set in the tower water heating scheme; real-time acquisition of the operating data of the magnetic levitation heat pump unit, and construction of a dynamic simulation model synchronously mapped to the magnetic levitation heat pump unit based on a parameterized structural model of the magnetic levitation heat pump unit; thermodynamic simulation of the tower water heating scheme under multiple operating conditions based on the digital twin model of the heat absorption and release process of the magnetic levitation heat pump, simulating the waste heat recovery process of the tower water circulation system; and dynamic adjustment of the compressor power and plate heat exchanger parameters by calculating the heat transfer efficiency under different operating conditions, feeding this feedback back to the magnetic levitation heat pump unit.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery technology for tower water, and in particular to a heat pump control method and system for tower water heat recovery heating based on digital twins. Background Technology

[0002] Traditional tower water heating mainly relies on direct steam heating or electric heating. The basic principle is to transfer the heat of high-temperature steam to the circulating water through a steam heat exchanger to raise the water temperature. Steam heating requires a large amount of fuel to generate high-temperature steam, resulting in low energy conversion efficiency and heat loss during steam transport. Steam heating temperature control depends on manual adjustment of valve openings. Furthermore, electric heating consumes a huge amount of electricity, leading to high operating costs and failing to meet the demands of green and low-carbon production. In recent years, heat pump technology has been increasingly applied to industrial waste heat recovery.

[0003] Existing heat pumps raise the temperature of low-temperature heat sources through compressors. After long-term operation, the plate heat exchanger accumulates dirt on its surface, leading to a decrease in the heat transfer coefficient. Furthermore, the lack of a dynamic correction mechanism results in a gradual deterioration of energy efficiency. Existing systems rely heavily on manual experience to adjust operating parameters, making it impossible to predict equipment status in real time, which leads to delayed maintenance and unexpected downtime. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of this invention is to provide a heat pump control method for tower water heat recovery heating based on digital twins, so as to solve the problems mentioned in the background art.

[0005] The technical solution adopted by this invention to solve its technical problem is: a heat pump control method for tower water heat recovery heating based on digital twins, wherein the magnetic levitation heat pump absorbs heat from the circulating water side of the tower water system and production line through the evaporator, and releases heat to heat the water tank through the condenser and plate heat exchanger, and further includes the following steps:

[0006] The magnetic levitation heat pump unit, which operates in the waste heat recovery process of the tower water circulation system under multiple operating conditions, enables the tower water heat recovery system to transfer heat within the temperature range set by the tower water heating scheme.

[0007] Real-time acquisition of operating data of magnetic levitation heat pump units; and construction of a dynamic simulation model of synchronous mapping of magnetic levitation heat pump units based on the structural parameterization model of magnetic levitation heat pump units.

[0008] Based on the digital twin model, the heat absorption and release process of the magnetic levitation heat pump is analyzed, and the thermodynamic simulation of the tower water heating scheme under multiple operating conditions is carried out to simulate the waste heat recovery process of the tower water circulation system.

[0009] By calculating the heat transfer efficiency under different operating conditions, the compressor power and plate heat exchanger parameters are dynamically adjusted and fed back to the magnetic levitation heat pump unit.

[0010] As a further improvement of the present invention: the magnetic levitation heat pump unit operating in the waste heat recovery process of the multi-condition tower water circulation system includes:

[0011] The magnetic levitation heat pump unit has a low-temperature heat absorption side and a high-temperature heat release side, as well as a magnetic levitation centrifugal compressor. The low-temperature heat absorption side absorbs heat in the evaporator. The refrigerant evaporates into refrigerant gas after absorbing heat from the water system of the absorption tower and the circulating water in the production line. After the high-temperature magnetic levitation centrifugal compressor does work, the high-temperature heat release side releases heat in the condenser. The condenser releases heat from the high-temperature and high-pressure refrigerant gas by condensation.

[0012] The magnetic levitation heat pump unit releases heat from the condenser, which is then regulated by a heating plate heat exchanger, and the heated circulating water is discharged into the tower water tank.

[0013] As a further improvement of the present invention: the magnetic levitation heat pump unit operating in the waste heat recovery process of the multi-condition tower water circulation system further includes:

[0014] Winter operation: The evaporator side of the magnetic levitation centrifugal compressor absorbs the first temperature of the circulating water. After the circulating water uses the first temperature to do work through the high-temperature magnetic levitation centrifugal compressor, the condenser compresses the refrigerant gas and releases heat. The heat released by the condenser is regulated by the heating plate heat exchanger, and the circulating water is heated to the first preset temperature and discharged into the tower water tank, raising the water temperature of the tower water tank.

[0015] Summer operation: The evaporator side of the magnetic levitation centrifugal compressor absorbs the second temperature of the circulating water. After the second temperature of the circulating water is used to do work through the high-temperature magnetic levitation centrifugal compressor, the condenser compresses the refrigerant gas and releases heat. The heat released by the condenser is regulated by the heating plate heat exchanger, and the circulating water is heated to the first preset temperature and discharged into the tower water tank, raising the water temperature of the tower water tank.

[0016] Adjustment of operating conditions: The heating plate heat exchanger absorbs the third temperature of the circulating water in the water tank, heats the circulating water to the first preset temperature, adjusts the circulating water in the water tank to the second preset temperature, and the condenser side of the magnetic levitation centrifugal compressor absorbs the fourth temperature of the circulating water, compresses it to the preset temperature, and then releases heat.

[0017] As a further improvement of the present invention: the real-time acquisition of the operating data of the magnetic levitation heat pump unit includes:

[0018] Real-time operating data of the magnetic levitation heat pump unit is collected by sensors, including evaporator and condenser temperatures, magnetic levitation compressor power, and tower water circulation flow rate. Based on the structural parameterized model of the magnetic levitation heat pump unit, a three-dimensional model of the magnetic levitation heat pump unit is constructed using BIM technology. According to the tower water temperature heating requirements, the heat transfer process under winter and summer conditions is simulated, and a three-dimensional dynamic simulation model of synchronous mapping of the magnetic levitation heat pump unit is constructed.

[0019] As a further improvement of the present invention: the construction of the three-dimensional model of the magnetic levitation heat pump unit using BIM technology includes:

[0020] The set temperature rise range of the evaporator and condenser, the compressor speed and power curves, and the plate heat exchanger heat transfer coefficient are marked on the three-dimensional dynamic simulation model.

[0021] The set temperature rise range for the evaporator and condenser includes:

[0022] Based on the winter operating conditions, the first temperature of the circulating water absorbed by the evaporator is adjusted according to the heating requirements of the tower water temperature. The compressor power is adjusted, and the condenser adjusts the circulating water in the heat exchanger tank to the second preset temperature.

[0023] According to the summer operating conditions, the second temperature of the circulating water absorbed by the evaporator is adjusted according to the heating requirements of the tower water temperature. The compressor power is adjusted and the condenser adjusts the circulating water in the heat exchanger tank to the second preset temperature.

[0024] The compressor speed-power curve includes the mathematical relationship between compressor speed Vt and compressor power P:

[0025] P = a * Vt 2 +b*Vt+c

[0026] Among them, the compressor speed-power curve coefficients a, b, and c can be fitted by measuring the power at different speeds using the least squares method;

[0027] The coefficients a, b, and c are corrected based on the compressor data detected by real-time sensors. The COP at different speeds is predicted by fitting the compressor speed-power curve. The predicted values ​​of the compressor speed-power curve are compared with the actual sensor data to correct the compressor speed-power curve coefficients.

[0028] As a further improvement of the present invention: the plate heat exchanger heat transfer coefficient includes:

[0029] By constructing a dynamic plate heat exchanger heat transfer model:

[0030]

[0031] Where K(t) is the real-time heat transfer coefficient, K0 is the initial heat transfer coefficient, β is the cleaning factor, which is affected by fouling on the plate heat exchanger surface, and v(b) is the real-time flow rate of the circulating water. c Where is the rated flow rate of the plate heat exchanger, and n is the flow rate versus heat transfer coefficient, 0.5. <n<1;

[0032] By using sensors to measure the thickness of dirt on the heat exchanger surface, the cleaning factor coefficient is adjusted, and the predicted value of the dynamic heat exchanger heat transfer model is compared with the actual sensor data to correct the heat transfer coefficient.

[0033] As a further improvement of the present invention: the thermodynamic simulation of the multi-condition tower water heating scheme includes:

[0034] By calculating the heating requirements of the evaporator-side temperature, the first preset temperature of the condenser-side, and the tower water temperature under winter and summer operating conditions, the heat absorption on the evaporator side and the heat release on the condenser side are calculated, and the dynamic equation of the inverse Carnot cycle and the COP prediction model are established.

[0035] As a further improvement of the present invention: the step of dynamically adjusting the compressor power and heat exchanger parameters by calculating the heat transfer efficiency under different operating conditions includes:

[0036] Based on real-time collected operating data of the magnetic levitation heat pump unit, and according to the tower water temperature heating requirements, the compressor power under different operating conditions is predicted, and the inverse Carnot cycle equation and heat transfer equation are used.

[0037] Q1=m·c·ΔT1

[0038] Q2=K(t)·A·ΔT LMTD

[0039]

[0040] Where Q1 is the heat absorbed by the evaporator, m is the circulating water flow rate, c is the specific heat capacity of the circulating water, and ΔT1 is the temperature difference between the inlet and outlet of the tower water on the evaporator side.

[0041] Q2 represents the heat released by the condenser, K(t) is the dynamic heat transfer coefficient, and ΔT LMTD The logarithmic mean temperature difference;

[0042] COP is the system energy efficiency ratio, W is the compressor power, and H is the heat transfer efficiency.

[0043] As a further improvement of the present invention: the step of dynamically adjusting the compressor power and heat exchanger parameters by calculating the heat transfer efficiency under different operating conditions includes:

[0044] Based on a PID controller, the compressor power is dynamically adjusted, and the compressor speed is adjusted according to the deviation between the set value and the actual value of the tower water temperature.

[0045] On the other hand, the present invention also provides a heat pump control system for tower water heat recovery heating based on digital twins, comprising the following steps:

[0046] Data acquisition module: A magnetic levitation heat pump unit operating in the waste heat recovery process of a multi-condition tower water circulation system, enabling the tower water heat recovery system to transfer heat within the temperature range set by the tower water heating scheme;

[0047] Digital twin model: Real-time acquisition of operating data of magnetic levitation heat pump unit, and construction of dynamic simulation model of synchronous mapping of magnetic levitation heat pump unit based on structural parameterization model of magnetic levitation heat pump unit;

[0048] Based on the digital twin model, the heat absorption and release process of the magnetic levitation heat pump is analyzed, and the thermodynamic simulation of the tower water heating scheme under multiple operating conditions is carried out to simulate the waste heat recovery process of the tower water circulation system.

[0049] Data feedback module: By calculating the heat transfer efficiency under different operating conditions, it dynamically adjusts the compressor power and plate heat exchanger parameters and feeds the results back to the magnetic levitation heat pump unit.

[0050] Compared with the prior art, the beneficial effects of the present invention are:

[0051] This invention absorbs heat from the tower water system and the circulating water side of the production line through the evaporator of a magnetic levitation heat pump, and releases the heat to heat the water tank through the condenser and plate heat exchanger. The operating status of the magnetic levitation heat pump unit is mapped in real time through a digital twin model, realizing dynamic heat transfer control under multiple operating conditions. By optimizing the heat transfer efficiency, the compressor power and plate heat exchanger parameters are dynamically adjusted to ensure that the tower water temperature is accurately controlled within the set range, thus saving energy. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the method flow of the present invention.

[0053] Figure 2 This is a schematic diagram of the system structure of the present invention. Detailed Implementation

[0054] In order to clearly and completely understand the technical solution, the present invention will be further described in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0056] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0057] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0058] Embodiments of the present invention provide a heat pump control method for tower water heat recovery heating based on digital twins. The magnetic levitation heat pump absorbs heat from the tower water system and the circulating water side of the production line through the evaporator, and releases the heat to heat the water tank through the condenser and plate heat exchanger. The method also includes the following steps:

[0059] The magnetic levitation heat pump unit, which operates in the waste heat recovery process of the tower water circulation system under multiple operating conditions, enables the tower water heat recovery system to transfer heat within the temperature range set by the tower water heating scheme.

[0060] Real-time acquisition of operating data of magnetic levitation heat pump units; and construction of a dynamic simulation model of synchronous mapping of magnetic levitation heat pump units based on the structural parameterization model of magnetic levitation heat pump units.

[0061] Based on the digital twin model, the heat absorption and release process of the magnetic levitation heat pump is analyzed, and the thermodynamic simulation of the tower water heating scheme under multiple operating conditions is carried out to simulate the waste heat recovery process of the tower water circulation system.

[0062] By calculating the heat transfer efficiency under different operating conditions, the compressor power and plate heat exchanger parameters are dynamically adjusted and fed back to the magnetic levitation heat pump unit.

[0063] This invention absorbs heat from the tower water system and the circulating water side of the production line through the evaporator of a magnetic levitation heat pump, and releases the heat to heat the water tank through the condenser and plate heat exchanger. The operating status of the magnetic levitation heat pump unit is mapped in real time through a digital twin model, realizing dynamic heat transfer control under multiple operating conditions. By optimizing the heat transfer efficiency, the compressor power and plate heat exchanger parameters are dynamically adjusted to ensure that the tower water temperature is accurately controlled within the set range, thus saving energy.

[0064] In one embodiment of the present invention, the magnetic levitation heat pump unit operating in the waste heat recovery process of the multi-condition tower water circulation system includes:

[0065] The magnetic levitation heat pump unit has a low-temperature heat absorption side and a high-temperature heat release side, as well as a magnetic levitation centrifugal compressor. The low-temperature heat absorption side absorbs heat in the evaporator. The refrigerant evaporates into refrigerant gas after absorbing heat from the water system of the absorption tower and the circulating water in the production line. After the high-temperature magnetic levitation centrifugal compressor does work, the high-temperature heat release side releases heat in the condenser. The condenser releases heat from the high-temperature and high-pressure refrigerant gas by condensation.

[0066] The magnetic levitation heat pump unit releases heat from the condenser, which is then regulated by a heating plate heat exchanger, and the heated circulating water is discharged into the tower water tank.

[0067] In one embodiment of the present invention, the magnetic levitation heat pump unit operating in the waste heat recovery process of the multi-condition tower water circulation system further includes:

[0068] Winter operation: The evaporator side of the magnetic levitation centrifugal compressor absorbs the first temperature of the circulating water. After the circulating water uses the first temperature to do work through the high-temperature magnetic levitation centrifugal compressor, the condenser compresses the refrigerant gas and releases heat. The heat released by the condenser is regulated by the heating plate heat exchanger, and the circulating water is heated to the first preset temperature and discharged into the tower water tank, raising the water temperature of the tower water tank.

[0069] Summer operation: The evaporator side of the magnetic levitation centrifugal compressor absorbs the second temperature of the circulating water. After the second temperature of the circulating water is used to do work through the high-temperature magnetic levitation centrifugal compressor, the condenser compresses the refrigerant gas and releases heat. The heat released by the condenser is regulated by the heating plate heat exchanger, and the circulating water is heated to the first preset temperature and discharged into the tower water tank, raising the water temperature of the tower water tank.

[0070] Adjustment of operating conditions: The heating plate heat exchanger absorbs the third temperature of the circulating water in the water tank, heats the circulating water to the first preset temperature, adjusts the circulating water in the water tank to the second preset temperature, and the condenser side of the magnetic levitation centrifugal compressor absorbs the fourth temperature of the circulating water, compresses it to the preset temperature, and then releases heat.

[0071] In this invention, during winter operation, the heated tower water is utilized and then returned to the production line side, mixing with the production line side water to form circulating water. The magnetic levitation heat pump mechanism absorbs heat from the low-temperature circulating water on the evaporator side, and the heat is raised to a high temperature by the magnetic levitation centrifugal compressor. This heat is then exchanged with the circulating water in the tower water tank via the condenser, raising the temperature of the circulating water in the tower water tank. The compressor speed can be dynamically adjusted to control the evaporator outlet temperature to >10°C, thus avoiding the risk of low-temperature freezing. The heating plate heat exchanger controls the heat release temperature of the circulating water after being heated by the condenser, ensuring the temperature uniformity of the tower water tank. During summer operation, the heated tower water is utilized and then returned to the production line side, mixing with the production line side water to form circulating water. The magnetic levitation heat pump mechanism absorbs heat from the low-temperature circulating water on the evaporator side, and the heat is raised to a high temperature by the magnetic levitation centrifugal compressor. After the compressor raises the heat to a high temperature, the water exchanges heat with the circulating water in the condenser and the tower water tank. The heating plate heat exchanger dynamically adjusts the circulating water flow rate and heat transfer coefficient to ensure that the water temperature is stable at the set value and reduce heat loss in high-temperature environments. During operation, after the RO water is pumped into the tower water tank, it mixes with the circulating water that has exchanged heat with the condenser and heating plate heat exchanger. The temperature of the circulating water in the tank decreases. At this time, the circulating water in the tank is pumped to the heating plate heat exchanger to exchange heat with the circulating water that has exchanged heat with the condenser, raising its temperature. Then, the circulating water that has exchanged heat with the condenser exits the condenser and, after rising in temperature, exits the condenser and is discharged into the heating plate heat exchanger. The circulating water pumped into the heating plate heat exchanger exchanges heat with the circulating water in the water tank to regulate its temperature. This process regulates the circulating water temperature in the water tank, achieving multi-stage heat utilization and maximizing waste heat recovery.

[0072] In one embodiment of the present invention, the real-time acquisition of operating data of the magnetic levitation heat pump unit includes:

[0073] Real-time operating data of the magnetic levitation heat pump unit is collected by sensors, including evaporator and condenser temperatures, magnetic levitation compressor power, and tower water circulation flow rate. Based on the structural parameterized model of the magnetic levitation heat pump unit, a three-dimensional model of the magnetic levitation heat pump unit is constructed using BIM technology. According to the tower water temperature heating requirements, the heat transfer process under winter and summer conditions is simulated, and a three-dimensional dynamic simulation model of synchronous mapping of the magnetic levitation heat pump unit is constructed.

[0074] In this embodiment, by using operational data such as evaporator and condenser temperatures, magnetic levitation compressor power, and tower water circulation flow rate of the magnetic levitation heat pump unit from sensors, a three-dimensional model of the magnetic levitation heat pump unit is constructed using BIM technology based on the structural parametric model of the magnetic levitation heat pump unit. This provides reliable input for the digital twin model, and parameters such as evaporator and condenser temperature ranges and compressor speed-power curves are labeled to achieve equipment status visualization.

[0075] In one embodiment of the present invention, the construction of a three-dimensional model of the magnetic levitation heat pump unit using BIM technology includes:

[0076] The set temperature rise range of the evaporator and condenser, the compressor speed and power curves, and the plate heat exchanger heat transfer coefficient are marked on the three-dimensional dynamic simulation model.

[0077] The set temperature rise range for the evaporator and condenser includes:

[0078] Based on the winter operating conditions, the first temperature of the circulating water absorbed by the evaporator is adjusted according to the heating requirements of the tower water temperature. The compressor power is adjusted, and the condenser adjusts the circulating water in the heat exchanger tank to the second preset temperature.

[0079] According to the summer operating conditions, the second temperature of the circulating water absorbed by the evaporator is adjusted according to the heating requirements of the tower water temperature. The compressor power is adjusted and the condenser adjusts the circulating water in the heat exchanger tank to the second preset temperature.

[0080] The compressor speed-power curve includes the mathematical relationship between compressor speed Vt and compressor power P:

[0081] P = a * Vt 2 +b*Vt+c

[0082] Among them, the compressor speed-power curve coefficients a, b, and c can be fitted by measuring the power at different speeds using the least squares method;

[0083] The coefficients a, b, and c are corrected based on the compressor data detected by real-time sensors. The COP at different speeds is predicted by fitting the compressor speed-power curve. The predicted values ​​of the compressor speed-power curve are compared with the actual sensor data to correct the compressor speed-power curve coefficients.

[0084] In this embodiment, BIM technology is used to construct a three-dimensional model of the magnetic levitation heat pump unit. Key parameters such as the temperature range of the evaporator / condenser, the compressor speed and power curve, and the plate heat exchanger heat transfer coefficient are directly marked in the model to achieve real-time visual monitoring of the equipment status.

[0085] The evaporator absorbs low-temperature circulating water. Based on the tower water heating requirements, the compressor operates according to an optimized curve, dynamically adjusting the compressor power. The condenser precisely controls the circulating water temperature through a heating plate heat exchanger. By fitting the experimental data to the coefficients, the compressor power at different speeds is accurately predicted. Sensors collect the operating data of the magnetic levitation heat pump unit in real time, dynamically correcting the model parameters to ensure prediction accuracy. Combined with the COP prediction model, the compressor operating range is optimized to improve the compressor power efficiency.

[0086] In one embodiment of the present invention, the plate heat exchanger heat transfer coefficient includes:

[0087] By constructing a dynamic plate heat exchanger heat transfer model:

[0088]

[0089] Where K(t) is the real-time heat transfer coefficient, K0 is the initial heat transfer coefficient, β is the cleaning factor, which is affected by fouling on the plate heat exchanger surface, and v(b) is the real-time flow rate of the circulating water. c Where is the rated flow rate of the plate heat exchanger, and n is the flow rate versus heat transfer coefficient, 0.5. <n<1;

[0090] By using sensors to measure the thickness of dirt on the heat exchanger surface, the cleaning factor coefficient is adjusted, and the predicted value of the dynamic heat exchanger heat transfer model is compared with the actual sensor data to correct the heat transfer coefficient.

[0091] In this embodiment, by monitoring the thickness of the plate heat exchanger fouling in real time and dynamically updating the cleaning factor, the heat transfer coefficient can be adjusted according to the circulating water flow rate.

[0092] In one embodiment of the present invention, the thermodynamic simulation of the multi-condition tower water heating scheme includes:

[0093] By calculating the heating requirements of the evaporator-side temperature, the first preset temperature of the condenser-side, and the tower water temperature under winter and summer operating conditions, the heat absorption on the evaporator side and the heat release on the condenser side are calculated, and the dynamic equation of the inverse Carnot cycle and the COP prediction model are established.

[0094] Furthermore, the step of dynamically adjusting the compressor power and heat exchanger parameters by calculating the heat transfer efficiency under different operating conditions includes:

[0095] Based on real-time collected operating data of the magnetic levitation heat pump unit, and according to the tower water temperature heating requirements, the compressor power under different operating conditions is predicted, and the inverse Carnot cycle equation and heat transfer equation are used.

[0096] Q1=m·c·ΔT1

[0097] Q2=K(t)·A·ΔT LMTD

[0098]

[0099] Where Q1 is the heat absorbed by the evaporator, m is the circulating water flow rate, c is the specific heat capacity of the circulating water, and ΔT1 is the temperature difference between the inlet and outlet of the tower water on the evaporator side.

[0100] Q2 represents the heat released by the condenser, K(t) is the dynamic heat transfer coefficient, and ΔT LMTD The logarithmic mean temperature difference;

[0101] COP is the system energy efficiency ratio, W is the compressor power, and H is the heat transfer efficiency.

[0102] In this embodiment, the heat absorption of the low-temperature heat source is calculated by real-time monitoring of circulating water flow rate and temperature difference. The dynamic heat transfer coefficient is combined with fouling factors and flow velocity to correct the heat release model in real time. By using real-time sensor data, the heat transfer coefficient and compressor efficiency are corrected in real time to improve control accuracy.

[0103] In one embodiment of the present invention, the step of dynamically adjusting the compressor power and heat exchanger parameters by calculating the heat transfer efficiency under different operating conditions includes:

[0104] Based on a PID controller, the compressor power is dynamically adjusted, and the compressor speed is adjusted according to the deviation between the set value and the actual value of the tower water temperature.

[0105] On the other hand, the present invention also provides a heat pump control system for tower water heat recovery heating based on digital twins, comprising the following steps:

[0106] Data acquisition module: A magnetic levitation heat pump unit operating in the waste heat recovery process of a multi-condition tower water circulation system, enabling the tower water heat recovery system to transfer heat within the temperature range set by the tower water heating scheme;

[0107] Digital twin model: Real-time acquisition of operating data of magnetic levitation heat pump unit, and construction of dynamic simulation model of synchronous mapping of magnetic levitation heat pump unit based on structural parameterization model of magnetic levitation heat pump unit;

[0108] Based on the digital twin model, the heat absorption and release process of the magnetic levitation heat pump is analyzed, and the thermodynamic simulation of the tower water heating scheme under multiple operating conditions is carried out to simulate the waste heat recovery process of the tower water circulation system.

[0109] Data feedback module: By calculating the heat transfer efficiency under different operating conditions, it dynamically adjusts the compressor power and plate heat exchanger parameters and feeds the results back to the magnetic levitation heat pump unit.

[0110] In one implementation, during winter operation, the low-temperature side of the production line is 15°C, and the high-temperature side is 18°C. The heated tower water is utilized and then returned to the production line side, mixing with the production line side water to form circulating water. A magnetic levitation heat pump absorbs heat from the 18°C ​​circulating water on the high-temperature side of the production line. After absorbing heat, the circulating water cools to 11°C and is discharged from the evaporator outlet. The absorbed heat is then raised to a high temperature by a magnetic levitation centrifugal compressor, and then exchanged heat with the circulating water in the tower water tank via a condenser. Specifically, the condenser exchanges heat with the tower water tank to form circulating water at 80°C. The condenser outlet discharges water, while simultaneously pumping 80°C circulating water to the heating plate heat exchanger. The heating plate heat exchanger adjusts the 80°C circulating water to 78°C, and then pumps it into the tower water tank, raising the temperature of the circulating water in the tank. Meanwhile, the 18°C ​​RO water pumped into the tower water tank mixes with the 78°C circulating water after heat exchange with the condenser and heating plate heat exchanger. The temperature of the circulating water in the tank decreases, forming 45°C circulating water. At this point, the 45°C circulating water in the tank is pumped to the heating plate heat exchanger, where it exchanges heat with the 80°C circulating water after heat exchange with the condenser, raising its temperature further. The circulating water temperature changes from 5°C to 75°C. This 75°C water then rises to 80°C after heat exchange at the condenser outlet and exits the condenser. It is then pumped into the water tank of the heating plate heat exchanger for heat exchange and temperature regulation. The water temperature in the tank is then adjusted, achieving multi-stage heat utilization and maximizing waste heat recovery. During the heat exchange process, a digital twin model maps the operating status of the magnetic levitation heat pump unit in real time, enabling dynamic heat transfer control under multiple operating conditions. By optimizing heat transfer efficiency, the compressor power and heat exchanger parameters are dynamically adjusted to ensure precise control of the tower water temperature within the set range, saving energy. The evaporator absorbs low-temperature circulating water, and the compressor operates according to the tower water heating requirements, dynamically adjusting its power. The condenser precisely controls the circulating water temperature through the heating plate heat exchanger. Experimental data fitting coefficients are used to accurately predict the compressor power at different speeds. Sensors collect real-time operating data of the magnetic levitation heat pump unit, dynamically correcting model parameters to ensure prediction accuracy. Combined with the COP prediction model, the compressor operating range is optimized, improving compressor power efficiency. After the circulating water in the tower water tank is heated to 78°C, it is sent to the extraction process line. In the heating plate of the extraction process line, it is mixed with steam to assist in heating, raising the temperature of the 78°C circulating water to 95°C. Steam is used to assist in heating to 90°C before it is supplied to the extraction equipment and the sugar dissolving equipment. In the sugar dissolving equipment, the ice water system combined with the cooling plate heat exchanger is used to assist in heat exchange and cooling according to different process requirements. After the heat exchange is completed, the circulating water is discharged to the production line side through the tower water system. After the product beverage is processed in the extraction equipment and the sugar dissolving equipment, it is output to the blending tank at 18°C ​​for blending.

[0111] In summary, after reading this invention document, those skilled in the art can make various other corresponding modifications to the technical solutions and concepts based on this invention without creative mental effort, and all of these modifications fall within the scope of protection of this invention.

Claims

1. A heat pump control method for tower water heat recovery heating based on digital twin, characterized in that, The magnetic levitation heat pump absorbs heat from the tower water system and the circulating water side of the production line through the evaporator, and releases the heat to heat the water tank through the condenser and plate heat exchanger. The process also includes the following steps: The magnetic levitation heat pump unit, which operates in the waste heat recovery process of the tower water circulation system under multiple operating conditions, enables the tower water heat recovery system to transfer heat within the temperature range set by the tower water heating scheme. Real-time acquisition of operating data of magnetic levitation heat pump units; and construction of a dynamic simulation model of synchronous mapping of magnetic levitation heat pump units based on the structural parameterization model of magnetic levitation heat pump units. The operation data of the magnetic levitation heat pump unit is collected in real time by sensors. The operation data includes the temperature of evaporator and condenser, the power of magnetic levitation compressor, and the circulation flow rate of tower water. Based on the structural parameterized model of the magnetic levitation heat pump unit, a three-dimensional model of the magnetic levitation heat pump unit is constructed using BIM technology. According to the heating requirements of tower water temperature, the heat transfer process under winter and summer conditions is simulated, and a three-dimensional dynamic simulation model of synchronous mapping of the magnetic levitation heat pump unit is constructed. The construction of a 3D model of the magnetic levitation heat pump unit using BIM technology includes: The set temperature rise range of the evaporator and condenser, the compressor speed and power curves, and the plate heat exchanger heat transfer coefficient are marked on the three-dimensional dynamic simulation model. The set temperature rise range for the evaporator and condenser includes: Based on the winter operating conditions, the first temperature of the circulating water absorbed by the evaporator is adjusted according to the heating requirements of the tower water temperature. The compressor power is adjusted, and the condenser adjusts the circulating water in the heat exchanger tank to the second preset temperature. According to the summer operating conditions, the second temperature of the circulating water absorbed by the evaporator is adjusted according to the heating requirements of the tower water temperature. The compressor power is adjusted and the condenser adjusts the circulating water in the heat exchanger tank to the second preset temperature. The compressor speed-power curve includes the mathematical relationship between compressor speed Vt and compressor power P: P=a*Vt 2 +b*Vt+c Among them, the compressor speed-power curve coefficients a, b, and c can be fitted by measuring the power at different speeds using the least squares method; The coefficients a, b, and c are corrected based on the compressor data detected by real-time sensors. The COP at different speeds is predicted by fitting the compressor speed-power curve. The predicted value of the compressor speed-power curve is compared with the actual sensor data to correct the compressor speed-power curve coefficients. The plate heat exchanger heat transfer coefficient includes: By constructing a dynamic plate heat exchanger heat transfer model: ； in, For real-time heat transfer coefficient, The initial heat transfer coefficient is 1. The cleaning agent is affected by the dirt on the heat exchanger surface. This refers to the real-time flow rate of the circulating water. Where is the rated flow rate of the plate heat exchanger, and n is the flow rate versus heat transfer coefficient, 0.

5. <n<1; By using sensors to measure the thickness of dirt on the heat exchanger surface, the cleaning factor coefficient is adjusted, and the heat transfer coefficient is corrected by comparing the predicted value of the dynamic heat exchanger heat transfer model with the actual sensor data. Based on the digital twin model, the heat absorption and release process of the magnetic levitation heat pump is analyzed, and the thermodynamic simulation of the tower water heating scheme under multiple operating conditions is carried out to simulate the waste heat recovery process of the tower water circulation system. By calculating the heating requirements of the evaporator side temperature, the first preset temperature of the condenser side, and the tower water temperature under winter and summer operating conditions, the heat absorption on the evaporator side and the heat release on the condenser side are calculated, and the dynamic equation of the reverse Carnot cycle and the COP prediction model are established. By calculating the heat transfer efficiency under different operating conditions, the compressor power and plate heat exchanger parameters are dynamically adjusted and fed back to the magnetic levitation heat pump unit. Based on real-time collected operating data of the magnetic levitation heat pump unit, and according to the tower water temperature heating requirements, the compressor power under different operating conditions is predicted, and the inverse Carnot cycle equation and heat transfer equation are used. ； in, Let m be the heat absorbed by the evaporator, m be the circulating water flow rate, and c be the specific heat capacity of the circulating water. The temperature difference between the inlet and outlet water on the evaporator side; To release heat for the condenser, The dynamic heat transfer coefficient, The logarithmic mean temperature difference; COP is the system energy efficiency ratio, W is the compressor power, and H is the heat transfer efficiency.

2. The heat pump control method for tower water heat recovery heating based on digital twin according to claim 1, characterized in that, The magnetic levitation heat pump unit operating in the waste heat recovery process of the multi-condition tower water circulation system includes: The magnetic levitation heat pump unit has a low-temperature heat absorption side and a high-temperature heat release side, as well as a magnetic levitation centrifugal compressor. The low-temperature heat absorption side absorbs heat in the evaporator. The refrigerant evaporates into refrigerant gas after absorbing heat from the water system of the absorption tower and the circulating water in the production line. After the high-temperature magnetic levitation centrifugal compressor does work, the high-temperature heat release side releases heat in the condenser. The condenser releases heat from the high-temperature and high-pressure refrigerant gas by condensation. The magnetic levitation heat pump unit releases heat from the condenser, which is then regulated by a heating plate heat exchanger, and the heated circulating water is discharged into the tower water tank.

3. The heat pump control method for tower water heat recovery heating based on digital twin according to claim 2, characterized in that, The magnetic levitation heat pump unit operating in the waste heat recovery process of the multi-condition tower water circulation system also includes: Winter operation: The evaporator side of the magnetic levitation centrifugal compressor absorbs the first temperature of the circulating water. After the circulating water uses the first temperature to do work through the high-temperature magnetic levitation centrifugal compressor, the condenser compresses the refrigerant gas and releases heat. The heat released by the condenser is regulated by the heating plate heat exchanger, and the circulating water is heated to the first preset temperature and discharged into the tower water tank, raising the water temperature of the tower water tank. Summer operation: The evaporator side of the magnetic levitation centrifugal compressor absorbs the second temperature of the circulating water. After the second temperature of the circulating water is used to do work through the high-temperature magnetic levitation centrifugal compressor, the condenser compresses the refrigerant gas and releases heat. The heat released by the condenser is regulated by the heating plate heat exchanger, and the circulating water is heated to the first preset temperature and discharged into the tower water tank, raising the water temperature of the tower water tank. Adjustment of operating conditions: The heating plate heat exchanger absorbs the third temperature of the circulating water in the water tank, heats the circulating water to the first preset temperature, adjusts the circulating water in the water tank to the second preset temperature, and the condenser side of the magnetic levitation centrifugal compressor absorbs the fourth temperature of the circulating water, compresses it to the preset temperature, and then releases heat.

4. The heat pump control method for tower water heat recovery heating based on digital twin according to claim 3, characterized in that, The method of dynamically adjusting the compressor power and heat exchanger parameters by calculating the heat transfer efficiency under different operating conditions includes: Based on a PID controller, the compressor power is dynamically adjusted, and the compressor speed is adjusted according to the deviation between the set value and the actual value of the tower water temperature.

5. A heat pump control system for tower water heat recovery heating based on digital twin, characterized in that, The heat pump control method for tower water heat recovery heating based on digital twins as described in any one of claims 1-4 further includes the following steps: Data acquisition module: A magnetic levitation heat pump unit operating in the waste heat recovery process of a multi-condition tower water circulation system, enabling the tower water heat recovery system to transfer heat within the temperature range set by the tower water heating scheme; Digital twin model: Real-time acquisition of operating data of magnetic levitation heat pump unit, and construction of dynamic simulation model of synchronous mapping of magnetic levitation heat pump unit based on structural parameterization model of magnetic levitation heat pump unit; Based on the digital twin model, the heat absorption and release process of the magnetic levitation heat pump is analyzed, and the thermodynamic simulation of the tower water heating scheme under multiple operating conditions is carried out to simulate the waste heat recovery process of the tower water circulation system. Data feedback module: By calculating the heat transfer efficiency under different operating conditions, it dynamically adjusts the compressor power and plate heat exchanger parameters and feeds the results back to the magnetic levitation heat pump unit.

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