An industrial waste heat driven centrifugal heat pump cascade heating and energy supply system

Abstract

This invention discloses an industrial waste heat-driven centrifugal heat pump cascade heating and energy supply system. The key technical features include: a multi-stage waste heat recovery system, a cascade centrifugal heat pump system, a multi-grade heat storage system, an intelligent control system, and an energy transmission network connecting the various systems. The multi-stage waste heat recovery system is used to recover industrial waste heat in stages according to temperature gradients, converting waste heat resources of different grades into usable heat energy at corresponding temperature levels. The cascade centrifugal heat pump system receives heat energy at different temperature levels output from the multi-stage waste heat recovery system and performs cascade heating through the multi-stage centrifugal heat pump unit, outputting high-grade heat energy at multiple temperature levels. This invention achieves coordinated output of multi-grade heat energy, significantly improving the system's flexibility and application range.

Description

Technical Field

[0001] This invention relates to the field of thermal energy, and in particular to an industrial waste heat-driven centrifugal heat pump cascade heating and energy supply system. Background Technology

[0002] Industrial production processes generate a large amount of waste heat, typically ranging from 30℃ to 250℃. Currently, the utilization rate of industrial waste heat is generally low, with a large amount of medium- and low-temperature waste heat being directly released into the environment, resulting not only in a huge waste of energy but also exacerbating thermal pollution.

[0003] Centrifugal heat pumps, as a highly efficient heat energy enhancement device, have advantages such as large single-unit capacity, high operating efficiency, and long service life, and have been widely used in the field of industrial waste heat recovery. However, existing centrifugal heat pump systems have the following drawbacks: Single temperature output limitation: Traditional centrifugal heat pump systems can usually only provide heat energy at a single temperature level, which cannot simultaneously meet the heat energy needs of different process stages in industrial production for different temperature levels, resulting in poor system flexibility and limited application scope.

[0004] Poor adaptability to waste heat quality: When the temperature and flow rate of industrial waste heat fluctuate, the COP (coefficient of performance) of traditional centrifugal heat pump systems will drop significantly, or even fail to operate normally, resulting in poor system stability.

[0005] Low efficiency under low load: When a centrifugal heat pump operates under partial load conditions, especially below 50% of the rated load, the isentropic efficiency of the compressor will decrease significantly, resulting in a decrease in the overall energy efficiency of the system.

[0006] Incomplete waste heat recovery: Existing systems can usually only recover waste heat within a specific temperature range. Low-grade waste heat with temperatures below the inlet temperature of the heat pump evaporator cannot be effectively recovered, resulting in low utilization of waste heat resources.

[0007] Low system integration: Existing systems often require separate waste heat recovery devices, heat pump units, thermal storage devices, and control systems. The lack of organic integration between these devices results in large system footprint, high investment costs, and complex control.

[0008] Therefore, there is an urgent need to develop an industrial waste heat-driven centrifugal heat pump energy supply system that can simultaneously provide heat energy at multiple temperature levels, adapt to fluctuations in waste heat quality, operate efficiently under low loads, thoroughly recover waste heat, and has a high degree of system integration. Summary of the Invention

[0009] In view of the problems mentioned in the background art, the present invention aims to provide an industrial waste heat driven centrifugal heat pump cascade heating and energy supply system to solve the problems raised in the background art.

[0010] The above-mentioned technical objective of the present invention is achieved through the following technical solution: An industrial waste heat-driven centrifugal heat pump cascade heating and energy supply system includes a multi-stage waste heat recovery system, a cascade centrifugal heat pump system, a multi-grade thermal storage system, an intelligent control system, and an energy transmission network connecting the various systems. The multi-stage waste heat recovery system is used to recover industrial waste heat in stages according to temperature gradients, converting waste heat resources of different grades into usable heat energy of corresponding temperature levels. The cascade centrifugal heat pump system is used to receive heat energy of different temperature levels output from the multi-stage waste heat recovery system and perform cascade heating through the multi-stage centrifugal heat pump unit, outputting high-grade heat energy of multiple temperature levels. The multi-grade thermal storage system is used to receive high-grade heat energy of multiple temperature levels output from the cascade centrifugal heat pump system and perform energy scheduling between heat energy of different temperature levels. The intelligent control system is used to collect industrial waste heat parameters and user heat demand parameters in real time, generate the optimal system operation strategy based on a predictive algorithm, and perform coordinated control of the multi-stage waste heat recovery system, the cascade centrifugal heat pump system, and the multi-grade thermal storage system.

[0011] Preferably, the multi-stage waste heat recovery system includes a waste heat classification treatment module and a waste heat flow rate regulation module; the waste heat classification treatment module is used to divide the industrial waste heat into three grade ranges—high temperature, medium temperature, and low temperature—according to the temperature characteristics, and to recover them separately; the waste heat flow rate regulation module is used to dynamically adjust the waste heat flow rate entering each grade range according to the operating status of the cascade centrifugal heat pump system.

[0012] Preferably, the cascade centrifugal heat pump system includes a first-stage heat pump module, a second-stage heat pump module, a third-stage heat pump module, and an interstage energy coupling module; each stage heat pump module receives heat energy at different temperature levels output by the multi-stage waste heat recovery system and raises it to a preset temperature level; the interstage energy coupling module is used to achieve energy complementarity between the heat pump modules at each stage.

[0013] Preferably, the operating temperature range of the first-stage heat pump module is 80℃-120℃ for evaporation and 130℃-160℃ for condensation; the operating temperature range of the second-stage heat pump module is 50℃-80℃ for evaporation and 90℃-120℃ for condensation; and the operating temperature range of the third-stage heat pump module is 20℃-50℃ for evaporation and 60℃-90℃ for condensation.

[0014] Preferably, the multi-grade thermal energy storage system includes a high-temperature thermal energy storage module, a medium-temperature thermal energy storage module, a low-temperature thermal energy storage module, and a cross-grade energy dispatching module; each thermal energy storage module is used to store thermal energy at a corresponding temperature level; the cross-grade energy dispatching module is used to exchange energy between thermal energy storage modules at different temperature levels.

[0015] Preferably, the intelligent control system includes a data acquisition module, a predictive analysis module, an optimization decision-making module, and an execution control module; the data acquisition module is used to collect system operating status parameters, industrial waste heat parameters, and user heat demand parameters in real time; the predictive analysis module is used to predict the changing trends of waste heat supply and heat demand over a future period; the optimization decision-making module is used to generate the optimal operating strategy for the system; and the execution control module is used to precisely control each system and module.

[0016] Preferably, the interstage energy coupling module can realize bidirectional energy transmission. When the heat source supply of a certain stage heat pump module is insufficient, it obtains supplementary energy from the adjacent heat pump module; when the heat source supply of a certain stage heat pump module is excessive, it transmits the excess energy to the adjacent heat pump module.

[0017] Preferably, the cross-grade energy scheduling module can realize unidirectional energy transmission, converting thermal energy of a higher temperature grade into thermal energy of a lower temperature grade.

[0018] In summary, the present invention has the following main beneficial effects: This invention achieves multi-grade heat energy synergistic output: This invention adopts a cascade centrifugal heat pump system, which can simultaneously provide heat energy at three temperature levels: high temperature, medium temperature, and low temperature, to meet the heat energy needs of different process stages in industrial production at different temperature levels, and greatly improve the system's flexibility and application range.

[0019] Significantly improves the adaptability of waste heat: This invention uses a multi-stage waste heat recovery system to recover industrial waste heat in stages according to temperature gradients and supplies it to heat pump modules of corresponding temperature levels. This ensures that each heat pump module always operates near its design conditions. Even if the temperature and flow rate of industrial waste heat fluctuate, the system can still maintain a high COP value, which significantly improves the stability and adaptability of the system.

[0020] Significantly improved low-load operation performance: All stages of the heat pump modules in this invention adopt wide-load high-efficiency operation technology, which can maintain an isentropic efficiency of more than 85% within a load range of 20%-100%, solving the problem of the significant efficiency drop of traditional centrifugal heat pumps under low load.

[0021] Achieving deep recovery of industrial waste heat: This invention can recover low-grade waste heat with a temperature as low as 20°C through a multi-stage waste heat recovery system, and raise it to a usable temperature through a third-stage heat pump module, thereby increasing the utilization rate of waste heat resources by more than 30%.

[0022] Constructing a highly integrated intelligent system: This invention organically integrates waste heat recovery, heat pump heating, heat storage and intelligent control. Through the intelligent control system, it realizes the collaborative work and optimized control between various systems, reduces the system's footprint and investment costs, and lowers operation and maintenance expenses.

[0023] Achieving flexible energy scheduling and complementarity: This invention realizes energy complementarity between heat pump modules at different levels through an inter-stage energy coupling module, and realizes energy exchange between thermal storage modules at different temperature levels through a cross-grade energy scheduling module, further improving the overall energy efficiency and operational flexibility of the system. Attached Figure Description

[0024] Figure 1 This is one of the system block diagrams of the present invention; Figure 2 This is the second system block diagram of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the 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.

[0026] Example 1 refer to Figure 1 and Figure 2 An industrial waste heat-driven centrifugal heat pump cascade heating and energy supply system includes a multi-stage waste heat recovery system, a cascade centrifugal heat pump system, a multi-grade thermal storage system, an intelligent control system, and an energy transmission network connecting the various systems. The multi-stage waste heat recovery system is used to recover industrial waste heat in stages according to temperature gradients, converting waste heat resources of different grades into usable heat energy of corresponding temperature levels. The cascade centrifugal heat pump system is used to receive heat energy of different temperature levels output from the multi-stage waste heat recovery system and perform cascade heating through the multi-stage centrifugal heat pump unit, outputting high-grade heat energy of multiple temperature levels. The multi-grade thermal storage system is used to receive high-grade heat energy of multiple temperature levels output from the cascade centrifugal heat pump system and perform energy scheduling between heat energy of different temperature levels. The intelligent control system is used to collect industrial waste heat parameters and user heat demand parameters in real time, generate the optimal system operation strategy based on prediction algorithms, and perform coordinated control of the multi-stage waste heat recovery system, the cascade centrifugal heat pump system, and the multi-grade thermal storage system.

[0027] The multi-stage waste heat recovery system includes a waste heat classification and treatment module and a waste heat flow regulation module. The waste heat classification and treatment module is used to divide industrial waste heat into three grade ranges: high temperature, medium temperature, and low temperature, based on the temperature characteristics of the waste heat, and to recover them separately. The waste heat flow regulation module is used to dynamically adjust the waste heat flow entering each grade range based on the operating status of the cascade centrifugal heat pump system.

[0028] The cascade centrifugal heat pump system includes a first-stage heat pump module, a second-stage heat pump module, a third-stage heat pump module, and an interstage energy coupling module. Each heat pump module receives heat energy at different temperature levels from the multi-stage waste heat recovery system and raises it to a preset temperature level. The interstage energy coupling module is used to achieve energy complementarity between the heat pump modules at each stage.

[0029] The operating temperature range of the first-stage heat pump module is 80℃-120℃ for evaporation and 130℃-160℃ for condensation; the operating temperature range of the second-stage heat pump module is 50℃-80℃ for evaporation and 90℃-120℃ for condensation; and the operating temperature range of the third-stage heat pump module is 20℃-50℃ for evaporation and 60℃-90℃ for condensation.

[0030] The multi-grade thermal energy storage system includes a high-temperature thermal energy storage module, a medium-temperature thermal energy storage module, a low-temperature thermal energy storage module, and a cross-grade energy dispatching module. Each thermal energy storage module is used to store thermal energy at its corresponding temperature level. The cross-grade energy dispatching module is used to exchange energy between thermal energy storage modules at different temperature levels.

[0031] The intelligent control system includes a data acquisition module, a predictive analysis module, an optimization decision-making module, and an execution control module. The data acquisition module is used to collect system operating status parameters, industrial waste heat parameters, and user heat demand parameters in real time. The predictive analysis module is used to predict the changing trends of waste heat supply and heat demand in the future. The optimization decision-making module is used to generate the optimal operating strategy for the system. The execution control module is used to precisely control each system and module.

[0032] Among them, the interstage energy coupling module can realize bidirectional energy transmission. When the heat source supply of a certain stage heat pump module is insufficient, it can obtain supplementary energy from the adjacent heat pump module; when the heat source supply of a certain stage heat pump module is excessive, it can transfer the excess energy to the adjacent heat pump module.

[0033] Among them, the cross-grade energy dispatching module can realize unidirectional energy transmission, converting thermal energy of a higher temperature grade into thermal energy of a lower temperature grade.

[0034] Among them, the present invention achieves multi-grade heat energy synergistic output: the present invention adopts a cascade centrifugal heat pump system, which can simultaneously provide heat energy at three temperature levels: high temperature, medium temperature and low temperature, to meet the heat energy needs of different process links in industrial production for different temperature levels, and greatly improve the system's flexibility and application range.

[0035] Among them, the present invention significantly improves the adaptability of waste heat grade: the present invention uses a multi-stage waste heat recovery system to grade and recover industrial waste heat according to temperature gradient, and supplies it to heat pump modules of corresponding temperature levels, so that each level of heat pump module always works near the design conditions. Even if the temperature and flow rate of industrial waste heat fluctuate, the system can still maintain a high COP value, which significantly improves the stability and adaptability of the system.

[0036] Among them, the present invention significantly improves the performance under low load: the heat pump modules of the present invention adopt wide load and high efficiency operation technology, which can maintain an isentropic efficiency of more than 85% within a load range of 20%-100%, thus solving the problem of the significant efficiency drop of traditional centrifugal heat pumps under low load.

[0037] Among them, the present invention achieves deep recovery of industrial waste heat: the present invention can recover low-grade waste heat with a temperature as low as 20°C through a multi-stage waste heat recovery system, and raise it to a usable temperature through a third-stage heat pump module, thereby increasing the utilization rate of waste heat resources by more than 30%.

[0038] Constructing a highly integrated intelligent system: This invention organically integrates waste heat recovery, heat pump heating, heat storage and intelligent control. Through the intelligent control system, it realizes the collaborative work and optimized control between various systems, reduces the system's footprint and investment costs, and lowers operation and maintenance expenses.

[0039] In this invention, flexible energy scheduling and complementarity are achieved: the inter-stage energy coupling module enables energy complementarity between heat pump modules at different levels, and the cross-grade energy scheduling module enables energy exchange between thermal storage modules at different temperature levels, further improving the overall energy efficiency and operational flexibility of the system.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A centrifugal heat pump cascade heating and energy supply system driven by industrial waste heat, characterized in that, The system comprises a multi-stage waste heat recovery system, a cascade centrifugal heat pump system, a multi-grade thermal storage system, an intelligent control system, and an energy transmission network connecting the various systems. The multi-stage waste heat recovery system is used to recover industrial waste heat in stages according to temperature gradients, converting waste heat resources of different grades into usable thermal energy at corresponding temperature levels. The cascade centrifugal heat pump system receives thermal energy at different temperature levels output from the multi-stage waste heat recovery system and performs cascade heating through multi-stage centrifugal heat pump units, outputting high-grade thermal energy at multiple temperature levels. The multi-grade thermal storage system receives high-grade thermal energy at multiple temperature levels output from the cascade centrifugal heat pump system and performs energy scheduling between different temperature levels of thermal energy. The intelligent control system collects industrial waste heat parameters and user heating demand parameters in real time, generates optimal system operation strategies based on predictive algorithms, and performs coordinated control of the multi-stage waste heat recovery system, the cascade centrifugal heat pump system, and the multi-grade thermal storage system.

2. The industrial waste heat driven centrifugal heat pump cascade heating and energy supply system according to claim 1, characterized in that, The multi-stage waste heat recovery system includes a waste heat classification and treatment module and a waste heat flow rate regulation module. The waste heat classification and treatment module is used to divide industrial waste heat into three grade ranges: high temperature, medium temperature, and low temperature, based on the temperature characteristics of the waste heat, and to recover them separately. The waste heat flow rate regulation module is used to dynamically adjust the waste heat flow rate entering each grade range based on the operating status of the cascade centrifugal heat pump system.

3. The industrial waste heat driven centrifugal heat pump cascade heating and energy supply system according to claim 1, characterized in that, The cascade centrifugal heat pump system includes a first-stage heat pump module, a second-stage heat pump module, a third-stage heat pump module, and an interstage energy coupling module. Each heat pump module receives heat energy at different temperature levels output by the multi-stage waste heat recovery system and raises it to a preset temperature level. The interstage energy coupling module is used to achieve energy complementarity between the heat pump modules at each stage.

4. The industrial waste heat driven centrifugal heat pump cascade heating and energy supply system according to claim 3, characterized in that, The first-stage heat pump module operates in a temperature range of 80℃-120℃ for evaporation and 130℃-160℃ for condensation; the second-stage heat pump module operates in a temperature range of 50℃-80℃ for evaporation and 90℃-120℃ for condensation; and the third-stage heat pump module operates in a temperature range of 20℃-50℃ for evaporation and 60℃-90℃ for condensation.

5. The industrial waste heat driven centrifugal heat pump cascade heating and energy supply system according to claim 1, characterized in that, The multi-grade thermal storage system includes a high-temperature thermal storage module, a medium-temperature thermal storage module, a low-temperature thermal storage module, and a cross-grade energy dispatching module. Each thermal storage module is used to store thermal energy at a corresponding temperature level; the cross-grade energy dispatching module is used to exchange energy between thermal storage modules at different temperature levels.

6. The industrial waste heat driven centrifugal heat pump cascade heating and energy supply system according to claim 1, characterized in that, The intelligent control system includes a data acquisition module, a predictive analysis module, an optimization decision-making module, and an execution control module. The data acquisition module is used to collect system operating status parameters, industrial waste heat parameters, and user heat demand parameters in real time. The predictive analysis module is used to predict the changing trends of waste heat supply and heat demand over a future period. The optimization decision-making module is used to generate the optimal operating strategy for the system. The execution control module is used to precisely control each system and module.

7. The industrial waste heat driven centrifugal heat pump cascade heating and energy supply system according to claim 3, characterized in that, The interstage energy coupling module enables bidirectional energy transfer. When the heat source supply of a certain stage heat pump module is insufficient, it obtains supplementary energy from the adjacent heat pump module; when the heat source supply of a certain stage heat pump module is excessive, it transfers the excess energy to the adjacent heat pump module.

8. The industrial waste heat driven centrifugal heat pump cascade heating and energy supply system according to claim 5, characterized in that, The cross-grade energy scheduling module can realize unidirectional energy transmission, converting thermal energy of a higher temperature grade into thermal energy of a lower temperature grade.

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