Heat exchange station energy-saving power supply system based on thermoelectric power generation and working method thereof

Abstract

The invention discloses a heat exchange station energy-saving power supply system based on thermoelectric power generation and a working method thereof, and belongs to the technical field of thermoelectric power generation. The system comprises a heat exchange station system and a thermoelectric power generation system coupled with the heat exchange station system. The heat exchange station system comprises a primary network water loop and a secondary network water loop which are composed of a thermal power plant, a heat exchanger and a heat user. The thermoelectric power generation system comprises a hot water diverter valve, a cold water diverter valve and a thermoelectric generator. The thermoelectric generator is composed of a hot water heat exchanger, a cold water heat exchanger and a thermoelectric power generation device clamped between the heat exchanger and the cold water heat exchanger. Part of primary network high-temperature water and secondary network low-temperature return water are introduced into the hot water heat exchanger and the cold water heat exchanger through the diverter valve, the temperature difference power generation device is driven to continuously generate power through the stable temperature difference between the two heat exchangers, and generated electric energy is supplied to the heat exchange station for use. On the premise that a main heat supply loop is not interfered and heat supply quality and safety are guaranteed, inherent waste heat temperature difference of the system is efficiently recycled, and dependence and operation power consumption of the heat exchange station on an external power grid are reduced.

Description

Technical Field

[0001] This invention relates to the field of thermoelectric power generation technology, specifically to an energy-saving power supply system for heat exchange stations based on thermoelectric power generation and its operating method. Background Technology

[0002] In centralized heating systems, heat exchange stations, as key facilities connecting heat sources and user terminals, play a crucial role in safely and efficiently transferring high-temperature heat energy generated by power plants to users' heating needs. A typical operating mode is as follows: high-temperature, high-pressure primary network water from the power plant is transported to the heat exchange station through the primary pipeline network and enters the primary side of the heat exchanger (usually a plate heat exchanger); simultaneously, low-temperature secondary network return water from the user enters the secondary side of the heat exchanger. The two exchange heat non-contactly within the heat exchanger. The primary network water cools and returns to the power plant, while the secondary network water absorbs heat, its temperature rises, and it is then driven by a circulating pump to be transported to the user's heating system (such as radiators, underfloor heating, etc.), releasing heat before returning to the heat exchange station, thus forming a closed-loop heating system.

[0003] Currently, the operation of these traditional heat exchange stations is highly dependent on municipal power grid supply. The core power equipment within the station must be connected to the grid to operate. With the continuous rise in energy costs, grid power consumption has become one of the main expenses in the operation of heat exchange stations. Under long-term operation, the high electricity costs not only significantly increase the operating costs of heating companies and compress their profit margins, but also have an adverse impact on the overall economic efficiency and energy efficiency of the heating system.

[0004] Therefore, a prominent drawback of existing technologies is that traditional heat exchange stations rely entirely on external grid power, resulting in heavy operating electricity costs and high system energy consumption, which is detrimental to energy conservation, emission reduction, and sustainable development in the heating industry. How to effectively reduce the power dependence of heat exchange stations and tap into the system's own energy-saving potential without affecting heating quality and system safety has become an urgent technical problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide an energy-saving power supply system for heat exchange stations based on thermoelectric power generation and its working method, so as to overcome the problem that traditional heat exchange stations rely entirely on external mains power, resulting in heavy operating electricity costs and high system energy consumption.

[0006] The present invention solves the above-mentioned technical problems through the following technical solution: The claims were amended by the agent after confirmation.

[0007] Compared with the prior art, the positive and progressive effects of the present invention are as follows: This invention provides an energy-saving power supply system for heat exchange stations based on thermoelectric power generation, comprising a heat exchange station system and a coupled thermoelectric power generation system. The heat exchange station system includes a primary network water circuit and a secondary network water circuit, consisting of a thermal power plant, heat exchangers, and heat users. The thermoelectric power generation system includes a hot water diversion valve, a cold water diversion valve, and a thermoelectric generator. The thermoelectric generator consists of a hot water heat exchanger, a cold water heat exchanger, and thermoelectric power generation devices sandwiched between them. Through the diversion valves, a portion of the high-temperature water from the primary network and the low-temperature return water from the secondary network are introduced into the hot water and cold water heat exchangers respectively. The stable temperature difference between the two drives the thermoelectric power generation devices to continuously generate electricity, which is used by the heat exchange station itself. This invention, without interfering with the main heating circuit and ensuring heating quality and safety, efficiently recovers and utilizes the inherent waste heat temperature difference of the system, significantly reducing the heat exchange station's dependence on the external power grid and its operating power consumption. It solves the problems of high operating costs and high energy consumption caused by traditional heat exchange stations' complete reliance on grid power, thus improving the overall energy efficiency and economy of the heating system. Attached Figure Description

[0008] The accompanying drawings are provided to further understand the invention and constitute a part of this invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0009] Figure 1 This is a connection diagram of an energy-saving power supply system for a heat exchange station based on thermoelectric power generation according to the present invention. Figure 2 This is a left view of a thermoelectric generator according to the present invention; Figure 3 This is a front view of a thermoelectric generator according to the present invention.

[0010] Among them, 1. Thermal power plants; 2. Heat users; 3. Primary network water pumps; 4. Secondary network water pumps; 5. Primary network water flow meters; 6. Secondary network water flow meters; 7. Primary network water inlet pressure gauges; 8. Primary network water return pressure gauges; 9. Secondary network water inlet pressure gauges; 10. Secondary network water return pressure gauges; 11. Primary network water inlet thermometers; 12. Primary network water return thermometers; 13. Secondary network water inlet thermometers; 14. 15. Secondary network water return thermometer; 16. Heat exchanger; 17. Hot water diversion valve; 18. Cold water diversion valve; 19. Hot water flow meter; 20. Cold water flow meter; 21. Thermoelectric generator; 22. Hot water heat exchanger; 23. Cold water heat exchanger; 24. Thermoelectric generator; 25. Cold water heat exchange plate; 26. Hot water heat exchange plate; 27. Cold water inlet; 28. Cold water outlet; 29. ​​Hot water inlet; 20. Hot water outlet. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0012] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0013] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0014] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0015] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. This is an explanation of the present invention and not a limitation thereof.

[0017] This invention provides an energy-saving power supply system for a heat exchange station based on thermoelectric power generation, comprising a heat exchange station system and a thermoelectric power generation system coupled thereto. The heat exchange station system includes a thermal power plant 1, a heat exchanger 15, a heat user 2, a primary network water inlet pressure gauge 7, a primary network water return pressure gauge 8, a secondary network water inlet pressure gauge 9, and a secondary network water return pressure gauge 10. The primary network water outlet of the thermal power plant 1 is connected to the primary network water inlet of the thermal power plant 1 sequentially via the primary network water inlet pressure gauge 7, the first inlet of the heat exchanger 15, the first outlet of the heat exchanger 15, and the primary network water return pressure gauge 8 to form a primary network water loop. The secondary network water outlet of the heat user 2 is connected to the secondary network water inlet of the heat user 2 sequentially via the secondary network water inlet pressure gauge 9, the second inlet of the heat exchanger 15, the second outlet of the heat exchanger 15, and the secondary network water return pressure gauge 10 to form a secondary network water loop. The thermoelectric power generation system includes a heat exchanger 15, a heat exchanger 15, a heat exchanger 15, a heat user 2, and a secondary network water return pressure gauge 10 to form a secondary network water loop. The system includes a water diversion valve 16, a cold water diversion valve 17, and a thermoelectric generator 20. The thermoelectric generator 20 includes a hot water heat exchanger 21, a cold water heat exchanger 22, and a thermoelectric generator 23, which is sandwiched between the hot water heat exchanger 21 and the cold water heat exchanger 22. The primary network water outlet of the thermal power plant 1 is connected to the inlet of the hot water heat exchanger 21 via the hot water diversion valve 16. The outlet of the hot water heat exchanger 21 flows into the primary network water inlet of the thermal power plant 1, which is used to divert part of the primary network water to the hot water heat exchanger 21. The secondary network water outlet of the heat user 2 is connected to the inlet of the cold water heat exchanger 22 via the cold water diversion valve 17. The outlet of the cold water heat exchanger 22 flows into the secondary network water inlet of the heat user 2, which is used to divert part of the secondary network water to the cold water heat exchanger 22. The primary network water flowing into the hot water heat exchanger 21 and the secondary network water flowing into the cold water heat exchanger 22 generate electricity by utilizing the temperature difference through the thermoelectric generator 23.

[0018] Working Principle: High-temperature, high-pressure hot water from the primary network generated by thermal power plant 1 enters heat exchanger 15 via a primary network water pump; simultaneously, secondary network water supplied for heating by user 2 also enters heat exchanger 15 via a secondary network water pump. The two networks exchange heat thoroughly within the heat exchanger, allowing the secondary network water to absorb sufficient heat from the primary network water to meet the heating needs of user 2. Based on this, a diversion valve is installed in each of the primary and secondary network loops to divert the matched flow rates of the primary and secondary network water from the main channel into the thermoelectric generator. Due to the temperature difference between the primary and secondary network water, they are separated into hot and cold water. The primary network water (hot water, 90-130°C) flows into the hot-end heat exchanger, while the secondary network water (cold water, 30-50°C) flows into the cold-end heat exchanger. The thermoelectric generator 23 is fastened between the hot-end and cold-end heat exchangers. Power is generated using the Seebeck effect of the internal thermoelectric material, utilizing the temperature difference between the hot and cold water. In the thermoelectric generator, the remaining heat from the primary water supply is transferred to the secondary water supply side for heating, ensuring the heating needs of heat user 2 within the heat exchange station. This system, through thermal parallel coupling of the thermoelectric generator system, simultaneously generates electricity while meeting the heat exchange requirements of heat user 2, contributing to energy-saving power supply for the heat exchange station system.

[0019] This system ingeniously recovers and utilizes the inherent but unused waste heat temperature difference within the centralized heating system to generate electricity, providing a supplementary or alternative power source for the heat exchange station itself. This directly reduces operating costs from the energy input side and improves the overall system energy efficiency. While ensuring that heating safety and quality are not affected, this solution effectively overcomes the core shortcomings of traditional heat exchange stations—"complete reliance on grid power, heavy electricity costs, and high system energy consumption"—providing a practical and efficient energy-saving technology approach for the sustainable development of the heating industry. Specifically, by coupling a temperature difference power generation system, the system utilizes the stable temperature difference between the high-temperature primary grid supply water and the low-temperature secondary grid return water inherent within the heat exchange station as the driving energy source. The previously unused heat energy difference is directly converted into electrical energy. The generated electricity can be used to partially or fully meet the power needs of the heat exchange station itself (such as circulating pumps and control systems), thereby significantly reducing electricity consumption from the municipal grid, directly lowering electricity costs at the source, and improving the economic efficiency of the heating system.

[0020] In traditional operation, after the primary network high-temperature water and the secondary network return water exchange heat in the heat exchanger, the residual heat quality difference (temperature difference) they carry is not further utilized, which essentially constitutes a waste of energy. By setting up a hot water diversion valve 16 and a cold water diversion valve 17, a portion of the primary network high-temperature water and the secondary network low-temperature return water are diverted to the thermoelectric power generation system without interfering with the normal operation of the main heating circuit. The thermoelectric power generation device 23 of this system continuously and stably generates electricity using the significant temperature difference between these two water flows, realizing the targeted recovery and efficient conversion of the previously wasted heat energy quality difference in the heating system, raising the overall energy utilization rate of the system to a new level, and conforming to the industry development trend of energy conservation and emission reduction.

[0021] The thermoelectric power generation system connects to the existing primary and secondary grid circuits in parallel bypass mode, and uses a diversion valve for flow regulation to ensure that the heat exchange process in the main circuit is not affected. The heat exchange between the primary and secondary grids within the main heat exchanger is maintained, thus ensuring stable heating parameters (temperature and flow rate) delivered to the user end, and unaffected heating quality. Simultaneously, the system retains all critical pressure gauges for continuous monitoring of the entire circuit, ensuring that the system operates within safe parameter ranges and overcoming potential issues of decreased heating reliability or safety hazards that might arise from solely pursuing energy conservation.

[0022] Preferably, the heat exchange station system also includes a primary network water pump 3 and a secondary network water pump 4. The primary network water pump 3 is located between the primary network water outlet of the thermal power plant 1 and the first inlet of the heat exchanger 15, and the secondary network water pump 4 is located between the secondary network water outlet of the heat user 2 and the second inlet of the heat exchanger 15.

[0023] As an active driving device, the water pump enhances the system's ability to overcome pipeline resistance and cope with load changes. The primary network water pump 3 drives the high-temperature water from the thermal power plant 1, ensuring sufficient flow rate and pressure in the primary network loop. The secondary network water pump 4 drives the low-temperature return water from users to circulate in the secondary network loop. The two pumps work together to establish and maintain a stable and controllable flow rate and pressure difference at key system nodes, ensuring a continuous and sufficient supply of high-temperature primary network water flowing through the hot water heat exchanger 21 and low-temperature secondary network return water flowing through the cold water heat exchanger 22. This creates and maintains a stable and significant temperature difference across the thermoelectric generator 23. This is the foundation for the thermoelectric power generation system to continuously and efficiently output electricity, overcoming the shortcomings of relying solely on the natural pressure difference of the pipeline network, which can lead to unstable temperature fields and fluctuating power generation efficiency.

[0024] The introduction of water pumps allows for active regulation of the main circuit flow rates in both the primary and secondary networks. Furthermore, by cooperating with the hot water diversion valve 16 and cold water diversion valve 17 installed on the diversion pipes, operators can more precisely control the amount of water diverted to the thermoelectric power generation system. This combined control mode of the main pump and diversion valves allows for independent optimization of the operating parameters of the thermoelectric power generation bypass without affecting the heating capacity of the main heat exchanger. For example, the diversion ratio can be dynamically adjusted based on changes in the primary network supply water temperature and the secondary network return water temperature, ensuring that the thermoelectric power generation system always operates within the optimal temperature difference range, maximizing power generation efficiency while prioritizing and fully meeting the heating needs of users.

[0025] Preferably, the heat exchange station system also includes a primary network water flow meter 5 and a secondary network water flow meter 6. The primary network water flow meter 5 is installed between the primary network water outlet of the thermal power plant 1 and the first inlet of the heat exchanger 15, and the secondary network water flow meter 6 is installed between the secondary network water outlet of the heat user 2 and the second inlet of the heat exchanger 15.

[0026] By installing the primary network water flow meter 5 between the outlet of the thermal power plant 1 and the inlet of the main heat exchanger, and the secondary network water flow meter 6 between the user return water outlet and the inlet of the main heat exchanger, the total water volume entering the core heat exchange links of the heat exchange station can be directly and accurately measured. The introduction of flow data upgrades the system operation status from qualitative judgment to quantitative analysis, providing precise input for all subsequent optimization control.

[0027] Preferably, the heat exchange station system also includes a primary network water inlet thermometer 11 and a secondary network water inlet thermometer 13. The primary network water inlet thermometer 11 is located between the primary network water outlet of the thermal power plant 1 and the first inlet of the heat exchanger 15, and the secondary network water inlet thermometer 13 is located between the secondary network water outlet of the heat user 2 and the second inlet of the heat exchanger 15.

[0028] By monitoring the total flow rate and temperature of the primary network, the total amount of high-grade heat sources available for use can be accurately calculated; by monitoring the total flow rate and return water temperature of the secondary network, the condition of the cold source can be assessed.

[0029] By placing the primary network water inlet thermometer 11 between the outlet of the thermal power plant 1 and the inlet of the main heat exchanger, the highest grade heat source temperature entering this heat exchange station can be measured directly and in real time. By placing the secondary network water inlet thermometer 13 between the user return water outlet and the inlet of the main heat exchanger, the lowest grade cold source temperature returning can be measured directly, providing the most fundamental thermodynamic parameter input for power prediction and optimized operation of the thermoelectric power generation system.

[0030] Based on real-time flow feedback control, it can ensure that the most suitable water volume is allocated to the power generation bypass while meeting the basic heating needs of the main heat exchanger. This ensures that the thermoelectric generator 23 always operates in the high-efficiency range, avoiding excessive diversion that affects heating or insufficient diversion that wastes power generation potential, thus achieving the optimal dynamic balance between power generation and heating.

[0031] Preferably, the heat exchange station system also includes a primary network water return thermometer 12 and a secondary network water return thermometer 14. The primary network water return thermometer 12 is located between the first outlet of the heat exchanger 15 and the primary network water return pressure gauge 8, and the secondary network water return thermometer 14 is located between the second outlet of the heat exchanger 15 and the secondary network water return pressure gauge 10.

[0032] By placing the primary network water return thermometer 12 at the first outlet of the heat exchanger (i.e., after the primary network water releases heat through the main heat exchanger) and the secondary network water return thermometer 14 at the second outlet of the heat exchanger (i.e., after the secondary network water absorbs heat through the main heat exchanger and is before being sent to the user), the water temperature at the heat exchanger outlet can be measured in real time and directly. Combined with the inlet water temperature measured by the inlet thermometer, the system can immediately calculate the actual temperature drop on the primary side and the actual temperature rise on the secondary side of the main heat exchanger. This allows operators to accurately grasp the actual completion status of the main heating task and provides a quantitative basis for evaluating whether the system's core functions meet the standards.

[0033] Thermoelectric power generation systems draw a portion of high-temperature primary network water and low-temperature secondary network return water from the main circuit via diversion valves. This inevitably affects the flow rate and temperature distribution in the main circuit. By adding return water thermometers, this impact can be precisely sensed and quantified. For example, increasing the opening of the hot water diversion valve by 16 degrees to increase power generation may reduce the total flow through the primary side of the main heat exchanger, potentially causing changes in the primary network return water temperature. By monitoring the return water temperature changes of the primary and secondary networks in real time, the impact of thermoelectric power generation bypass operation on the main heating effect can be dynamically assessed.

[0034] Preferably, the heat exchange station system also includes a hot water flow meter 18 and a cold water flow meter 19. The primary network water outlet of the thermal power plant 1 is connected to the inlet of the hot water heat exchanger 21 via the hot water flow meter 18 and the hot water diversion valve 16 in sequence. The secondary network water outlet of the heat user 2 is connected to the inlet of the cold water heat exchanger 22 via the cold water flow meter 19 and the cold water diversion valve 17 in sequence.

[0035] The power generation efficiency of the thermoelectric generator 23 depends not only on the temperatures of the hot and cold water, but also on the flow rate of the medium flowing through the heat exchangers on both sides. Insufficient flow rate may lead to insufficient heat exchange, preventing the establishment of an effective temperature difference across the generator chip; excessive flow rate may result in wasted power consumption, or even affect the establishment of the temperature difference due to excessively high flow velocity and insufficient heat exchange time. By adding a hot water flow meter 18 and a cold water flow meter 19, the opening of the hot water diversion valve 16 and the cold water diversion valve 17 can be dynamically and precisely adjusted, ensuring that the flow rates of hot and cold water through the generator module are always controlled within the optimal range. This ensures that the thermoelectric power generation process operates in a highly efficient and stable state, thereby maximizing the power generation benefit of each diverted heat and overcoming the problems of coarse control and efficiency loss caused by estimating flow rate solely based on valve opening.

[0036] Preferably, the hot water heat exchanger 21 is an indirect-contact hot water heat exchanger 21, and the cold water heat exchanger 22 is an indirect-contact cold water heat exchanger 22.

[0037] The power generation performance of the thermoelectric generator 23 is highly dependent on whether its hot and cold end surfaces can obtain uniform, stable and efficient heat transfer. The core advantage of the partition structure is that it can provide a large area and flat heat exchange surface. These heat exchange plates can be directly and tightly attached to the large area surface of the thermoelectric generator 23 or connected through thermally conductive materials to form a heat conduction path with extremely low thermal resistance, so as to efficiently and uniformly transfer heat to the entire plate surface, thereby ensuring that the thermoelectric generator 23 establishes a uniform and significant temperature difference field on its entire working surface.

[0038] In a specific embodiment of the present invention, both the hot water heat exchanger 21 and the cold water heat exchanger 22 are indirect plate heat exchangers, and the hot water heat exchanger 21 and the cold water heat exchanger 22 are not in direct contact with each other, but are sandwiched between each other by a thermoelectric generator 23. The hot water heat exchanger 21 and the cold water heat exchanger 22 are not a complete heat exchanger, but are each composed of multiple hot water heat exchange plates and cold water heat exchange plates. The thermoelectric generator 23 is not a complete unit, but is composed of a large number of small thermoelectric generators connected together. Each hot water heat exchange plate and cold water heat exchange plate is sandwiched between a thermoelectric generator 23. A certain number of thermoelectric generators and a large number of thermoelectric generators connected by wires constitute a complete thermoelectric generator device 23. The number of hot water heat exchange plates and cold water heat exchange plates in hot water heat exchanger 21 and cold water heat exchanger 22 are almost the same. In order to achieve a constant temperature difference between the two ends of the thermoelectric generator device 23, it is necessary to ensure that the heat exchange effect of hot and cold water in hot water heat exchanger 21 and cold water heat exchanger 22 is the same. Therefore, it is necessary to adjust the opening of hot water diversion valve 16 and cold water diversion valve 17 to ensure that the values ​​of hot water flow meter 18 and cold water flow meter 19 are at the same level, so as to achieve a comparable heat exchange effect of hot and cold water. In use, the pressure difference of the secondary network water pipeline is calculated based on the difference between the secondary network water inlet pressure gauge 9 and the secondary network water return pressure gauge 10. The number of hot water heat exchange plates and cold water heat exchange plates in the hot water heat exchanger 21 and the cold water heat exchanger 22 are set according to the pressure difference to ensure that the primary network water and the secondary network water can flow normally through the hot water heat exchanger 21 and the cold water heat exchanger 22 under this pressure difference.

[0039] See Figure 2 and Figure 3 The thermoelectric generator consists of a portion of cold water heat exchange plates 26, hot water heat exchange plates 27, and thermoelectric generators 23. The actual thermoelectric generator is composed of multiple thermoelectric generator modules arranged side by side as shown in the diagram. Several cold water heat exchange plates 26 form a cold water heat exchanger 21, and several hot water heat exchange plates 27 form a hot water heat exchanger 22. Hot water heat exchange plates 25 and cold water heat exchange plates 24 are arranged alternately. Except for the top and bottom two heat exchange plates, which are both set as cold water heat exchange plates 24, each hot water heat exchange plate 25 is sandwiched between two cold water heat exchange plates 24, and each cold water heat exchange plate 24 is sandwiched between two hot water heat exchange plates 25. The cold water inlet 26 and the hot water outlet 29 are on one side, and the cold water outlet 27 and the hot water inlet 28 are on one side, so as to realize the counter-flow arrangement of cold and hot water inlet and outlet, and ensure that the temperature difference of the thermoelectric generator 23 is consistent at all points along the flow direction.

[0040] Preferably, the thermoelectric generator 20 further includes a power conversion module for converting the direct current generated by the thermoelectric generator 23 into alternating current and supplying power to the electrical equipment.

[0041] Thermoelectric generators 23 typically output low-voltage direct current, whose voltage and current characteristics are unstable and fluctuate with temperature differences. This makes them unsuitable for use by conventional AC power supply equipment (such as circulating water pumps, control systems, and electric valves) within heat exchange stations. By integrating power conversion modules (such as DC-AC inverters or DC-DC converters with voltage regulation), the original unstable direct current can be converted and stabilized into standardized AC power (such as 220V / 380V, 50Hz). This allows the electricity generated by the thermoelectric generator system to be seamlessly connected and directly utilized, replacing or supplementing the existing AC power from the municipal power grid. This substantially and conveniently reduces dependence on mains power, translating energy-saving potential into direct operating cost savings.

[0042] In a specific embodiment of the present invention, each small thermoelectric generator can be understood as a voltage source. The voltage magnitude is related to the temperature difference across the thermoelectric generator 23. By connecting them in series and parallel, the output voltage, internal resistance, and output current of the overall thermoelectric generator 23 can be changed. Each small thermoelectric generator is equivalent to a voltage source that can only generate unidirectional current. Therefore, the electricity generated by the thermoelectric generator 23 is direct current (DC). It needs to be regulated in the thermoelectric generator 20 before it can supply power to external electrical equipment. An internal transformer system first passes the DC electricity generated by the thermoelectric generator 23 through a transformer to ensure its output voltage meets the voltage requirements for normal electrical operation. Then, through an inverter circuit, the DC electricity is converted to alternating current (AC) to supply the electrical equipment. Due to the voltage source characteristics of the thermoelectric generator 23, its output power reaches its maximum when the external load resistance equals its internal resistance. Therefore, the thermoelectric generator 20 has a variable resistor inside, which is connected in series or parallel with the external electrical equipment to ensure that the external load resistance equals its internal resistance, allowing the electrical equipment to operate at maximum output power.

[0043] Preferably, the thermoelectric generator 23 is made of P-type bismuth telluride and N-type bismuth telluride materials, as well as copper electrodes for electrical connection and a ceramic plate for fixing.

[0044] The thermoelectric power generation device 23 is mainly composed of bismuth telluride, a thermoelectric material suitable for medium and low temperatures of 0-150°C. The thermoelectric material utilizes the Seebeck effect, where semiconductor charge carriers migrate from the hot end to the cold end under a certain temperature difference, thereby generating current. Hundreds of pairs of P-type and N-type bismuth telluride are connected in series by copper electrodes and encapsulated to form the thermoelectric power generation device 23.

[0045] Bismuth telluride (Bi2Te3) is currently a mature commercial material with the highest thermoelectric figure of merit (ZT value) in the medium and low temperature range (room temperature to 300°C). By pairing P-type and N-type bismuth telluride materials to construct a thermoelectric power generation device 23, the thermoelectric conversion efficiency of the power generation module can reach or approach the theoretical optimal value under current technological conditions within the actual operating temperature range of the heat exchange station. This ensures that every degree of temperature difference between the heat source (high-temperature primary network water) and the cold source (low-temperature secondary network return water) can be captured and converted into electrical energy with maximum efficiency. This fundamentally overcomes the technical defects of low power generation efficiency and insignificant energy-saving effects caused by material temperature mismatch, achieving perfect matching with the operating temperature range of the heat exchange station and maximizing thermoelectric power generation efficiency.

[0046] Based on the same inventive concept, the present invention also provides a method for operating the energy-saving power supply system for a heat exchange station based on thermoelectric power generation as described above, comprising the following steps: Obtain the data from the primary water inlet pressure gauge 7 and the primary water return pressure gauge 8, and calculate the pipeline pressure difference A of the primary water circuit. Specifically: Pipeline pressure difference A of the primary water circuit = data from the primary water inlet pressure gauge 8 - data from the primary water return pressure gauge 7. Obtain the data from the secondary network water inlet pressure gauge 9 and the secondary network water return pressure gauge 10, and calculate the pipeline pressure difference B of the secondary network water circuit. Specifically: Pipeline pressure difference B of the secondary network water circuit = data from the secondary network water inlet pressure gauge 10 - data from the secondary network water return pressure gauge 9. Determine whether the pipe pressure difference A of the primary water circuit is equal to the pipe pressure difference B of the secondary water circuit. If the result is yes, maintain the current opening of the hot water diversion valve 16 and the cold water diversion valve 17. If the result is no, adjust the opening of the hot water diversion valve 16 and the cold water diversion valve 17 to make the water flow into the hot water heat exchanger 21 and the cold water heat exchanger 22 basically equal, and maximize the water flow without affecting the operation of the heat exchange station itself, so as to maintain a stable temperature difference across the thermoelectric generator 23 for efficient power generation.

[0047] By real-time monitoring and comparison of the pipe pressure difference (A and B) between the primary and secondary water network loops, and using their equality as the core criterion to adjust the diversion valve: when the water flow rates into the hot water heat exchanger 21 (hot end) and the cold water heat exchanger 22 (cold end) are approximately equal, the hydraulic and thermal conditions of the two heat exchangers are most well-matched, which is most conducive to establishing and maintaining a stable and effective temperature difference field on both sides of the power generation device. By transforming the complex flow balance problem into monitoring and comparing the pressure difference between the two pipe network loops, which is easy to measure in real time and is highly reliable, the control logic is simple, direct, and highly reliable. This ensures that the thermoelectric power generation process always operates under optimal or near-optimal conditions, thereby maximizing power generation efficiency and energy recovery rate.

[0048] The operating conditions of the heating system (such as heat source temperature and user load) may change, potentially causing fluctuations in flow and pressure in the primary and secondary main circuits. Traditional fixed-opening or simple temperature-controlled diversion strategies are ill-suited to these changes, easily leading to flow imbalances on both sides, which in turn cause fluctuations in the power generation temperature difference and reduced efficiency. The working method of this invention uses closed-loop feedback regulation to continuously compare pressure differences A and B. Once a change in operating conditions causes an imbalance in the pressure difference (i.e., A≠B), the system immediately corrects the imbalance by adjusting the opening of the hot water diversion valve 16 and the cold water diversion valve 17, dynamically restoring the flow balance on both sides. This allows the thermoelectric power generation system to actively follow changes in the main heating system, maintaining a consistently high-efficiency operating state, improving the robustness and adaptability of the entire energy-saving power supply system to complex and dynamic operating conditions, and ensuring the continuity and stability of energy-saving effects.

[0049] In a specific embodiment of the present invention, see Figure 1The heat exchange station energy-saving power supply system based on thermoelectric power generation includes a traditional heat exchange station system and a thermoelectric power generation system coupled with thermoelectric power generation equipment. The two coupled systems are in a thermal parallel relationship. The water flow of the heat exchange station system is the main component, and the thermoelectric power generation system draws part of the water flow from the heat exchange station system pipeline to generate electricity through thermoelectric difference, and then flows back into the heat exchange station system pipeline.

[0050] The heat exchange station system includes a thermal power plant 1, a heat user 2, a primary network water pump 3, a secondary network water pump 4, a primary network water flow meter 5, a secondary network water flow meter 6, a primary network water inlet pressure gauge 7, a primary network water return pressure gauge 8, a secondary network water inlet pressure gauge 9, a secondary network water return pressure gauge 10, a primary network water inlet thermometer 11, a primary network water return thermometer 12, a secondary network water inlet thermometer 13, a secondary network water return thermometer 14, and a heat exchanger 15.

[0051] The high-temperature, high-pressure hot water generated after industrial production at thermal power plant 1 flows into the primary network water pipeline system via primary network water pump 3. The primary network water is mainly divided into two paths: one path leads to heat exchanger 15 for heat exchange with secondary network water; the other path, controlled by hot water diversion valve 16, enters the thermoelectric power generation system. After power generation, it returns to thermal power plant 1 along with the primary network water exiting heat exchanger 15 to await reheating. The secondary network water required for heating by heat user 2 enters the secondary network pipeline system via secondary network water pump 4. The secondary network water is mainly divided into two paths: one path leads to heat exchanger 15 for heat exchange with primary network water; the other path, controlled by cold water diversion valve 17, enters the thermoelectric power generation system. After power generation, it returns to heat user 2 along with the secondary network water exiting heat exchanger 15 to provide heating for the user. Heat exchanger 15 is a partition plate type heat exchanger.

[0052] The primary water pump 3 and the secondary water pump 4 are located at opposite ends of the heat exchanger 15 to ensure that the primary and secondary water flows in counter-current distribution within the heat exchanger 15, achieving better heat exchange and providing nearly equal temperature differences at various locations of the thermoelectric generator 23 in the thermoelectric power generation system. The thermoelectric power generation system with the thermoelectric generator 23 includes a hot water diversion valve 16, a cold water diversion valve 17, a hot water flow meter 18, a cold water flow meter 19, a thermoelectric generator 20, a hot water heat exchanger 21, a cold water heat exchanger 22, and the thermoelectric generator 23.

[0053] Part of the primary network water (hot water) enters the hot water heat exchanger 21 of the thermoelectric generator 20 through the hot water diversion valve 16; part of the secondary network water (cold water) enters the cold water heat exchanger 22 of the thermoelectric generator 20 through the cold water diversion valve 17.

[0054] Cold water and hot water provide corresponding temperatures to hot water heat exchanger 21 and cold water heat exchanger 22, respectively.

[0055] The thermoelectric generator 23 is fixed between the hot water heat exchanger 21 and the cold water heat exchanger 22, and generates electricity by utilizing the temperature difference between the two. The final electrical energy is collected in the thermoelectric generator 20 to supply power to the electrical equipment.

[0056] The system includes a traditional heat exchange station operation system and a thermoelectric generator system coupled with it, which is equipped with a thermoelectric generator 23. In the primary network water circuit of the system, the high temperature and high pressure primary network water generated by the thermal power plant 1 is pumped into the primary network pipeline. One stream of water enters the heat exchanger to exchange heat with the secondary network water and release heat, while the other stream of water enters the thermoelectric generator 20 to generate electricity and transfer the remaining energy to the secondary network water.

[0057] The two streams of water are then combined into one and returned to thermal power plant 1 to await heating.

[0058] The secondary network water circuit of this system is formed by the low-temperature secondary network water generated after the heating user 2 starts heating. The water is pumped into the secondary network pipeline. One stream of water enters the heat exchanger to exchange heat with the primary network water and absorb heat. The other stream of water enters the thermoelectric generator 20 to generate electricity and absorb the remaining heat of the primary network water.

[0059] The two water streams are then combined into one and returned to the second heat user for heating.

[0060] Specifically, both the hot water heat exchanger 21 and the cold water heat exchanger 22 are indirect heat exchangers.

[0061] Furthermore, the hot water heat exchanger 21 and the cold water heat exchanger 22 are not in direct contact with each other, but are sandwiched between a thermoelectric generator 23; the hot water diversion valve 16 and the cold water diversion valve 17 are located on both sides of the thermoelectric generator 20, respectively, achieving counter-current flow in the heat exchanger; the hot water heat exchanger 21 and the cold water heat exchanger 22 are each composed of multiple hot water heat exchange plates and cold water heat exchange plates. The hot water heat exchange plates and cold water heat exchange plates are arranged alternately, except for the top and bottom two heat exchange plates which are set as cold water heat exchange plates, each hot water heat exchange plate is sandwiched between two cold water heat exchange plates, and each cold water heat exchange plate is sandwiched between two hot water heat exchange plates.

[0062] Specifically, the thermoelectric generator 23 is composed of a large number of small thermoelectric generators connected together; the flow of hot and cold water in the system is driven by the pressure difference between the primary and secondary water supply pipes; the flow rates of the primary and secondary water supply passing through the thermoelectric generator are nearly the same; the thermoelectric generator 23 is mainly composed of bismuth telluride, a thermoelectric material suitable for medium and low temperatures. Utilizing the Seebeck effect, under a certain temperature difference, semiconductor charge carriers migrate from the hot end to the cold end, thus generating current. Hundreds of pairs of P-type and N-type bismuth telluride are connected in series with alternating copper electrodes, and after encapsulation, form the thermoelectric generator 23; each small thermoelectric generator can be understood as a voltage source, the voltage magnitude of which is related to the temperature difference across the thermoelectric generator 23. By connecting them in series and parallel, the output voltage, internal resistance, and output current of the overall thermoelectric generator 23 can be changed; each The voltage source equivalent to a small thermoelectric generator can only generate unidirectional current. Therefore, the electricity generated by the thermoelectric generator 23 is direct current (DC). It needs to be regulated in the thermoelectric generator 20 before it can supply power to the external electrical equipment. There is an internal power conversion system that first passes the DC electricity generated by the thermoelectric generator 23 through a transformer so that its output voltage can meet the voltage requirements of the electrical appliances. Then, it passes through an inverter circuit to convert the DC electricity into alternating current (AC). After voltage stabilization, it is supplied to the electrical equipment. Due to the voltage source characteristics of the thermoelectric generator 23, its output power reaches its maximum when the external load resistance is equal to its internal resistance. Therefore, the thermoelectric generator 20 has a variable resistor inside, which is connected in series or parallel with the external electrical equipment to achieve the same resistance as the external load, so that the electrical equipment can use electricity at its maximum output power.

[0063] When the heat exchange station system is in operation, the system will set the inlet and outlet water temperatures of the primary and secondary networks according to parameters such as local outdoor temperature, building type, and heating area, and perform flow matching. The system will also calculate the pressure difference of the primary network water pipeline based on the difference between the primary network water inlet pressure gauge 7 and the primary network water return pressure gauge 8.

[0064] Calculate the differential pressure in the secondary water supply pipeline based on the difference between the pressure gauge 9 (for the secondary water supply inlet) and the pressure gauge 10 (for the secondary water supply return).

[0065] Based on the smaller of the two values, the same number of hot water heat exchangers 21 and cold water heat exchangers 22 are matched according to the magnitude of the flow resistance (pressure drop) of the heat exchangers.

[0066] Adjust the opening of the hot water diversion valve 16 and the cold water diversion valve 17 to make the flow rates entering the hot water heat exchanger 21 and the cold water heat exchanger 22 nearly equal, ensuring that the heat exchange capacity of the hot and cold water is the same, and maintaining a stable temperature difference across the thermoelectric generator 23 to generate electricity.

[0067] When the outdoor temperature changes, the heat exchange station system will adjust the inlet and outlet water temperatures and flow rates of the primary and secondary networks according to the target building's heating temperature. The number of hot water heat exchangers 21, cold water heat exchangers 22, and thermoelectric generators 23 working in the thermoelectric power generation system will also change accordingly. After adjusting the opening of the hot water diversion valve 16 and the cold water diversion valve 17, the system will maintain stable power generation.

[0068] The flow of hot and cold water is driven by the pressure difference between the primary and secondary water inlet and return pipes. Therefore, the pressure difference in the primary water pipes must be calculated based on the difference between the primary water inlet pressure gauge 7 and the primary water return pressure gauge 8, and the pressure difference in the secondary water pipes must be calculated based on the difference between the secondary water inlet pressure gauge 9 and the secondary water return pressure gauge 10. Based on the magnitude of the pressure difference and the flow resistance (pressure drop) of the heat exchangers, the number of hot water heat exchange plates and cold water heat exchange plates in the hot water heat exchanger 21 and the cold water heat exchanger 22 are determined to ensure that the primary and secondary water can flow normally through the hot water heat exchanger 21 and the cold water heat exchanger 22 under this pressure difference. The number of hot water heat exchange plates and cold water heat exchange plates in heat exchanger 21 and cold water heat exchanger 22 are almost the same. In order to achieve a constant temperature difference between the two ends of thermoelectric generator 23, it is necessary to ensure that the heat exchange effect of hot and cold water in hot water heat exchanger 21 and cold water heat exchanger 22 is the same. Therefore, it is necessary to adjust the opening of hot water diversion valve 16 and cold water diversion valve 17 to ensure that the values ​​of hot water flow meter 18 and cold water flow meter 19 are at the same level, so as to achieve comparable heat exchange effect of hot and cold water. The energy-saving power supply system for heat exchange station based on thermoelectric power generation provided by this invention has found an energy-saving power supply measure for the continuous operation of water pumps and lighting equipment in the heat exchange station system, reducing the consumption and waste of electricity.

[0069] Compared to traditional thermoelectric generators, thermoelectric generator systems do not introduce additional power-consuming equipment to drive the system. Instead, they utilize the pressure drop within the heat exchange station itself to drive the system, thus reducing external consumption.

[0070] Compared to other waste heat recovery power generation systems, thermoelectric power generation systems have advantages such as being all-solid-state, small in size, and simple in structure, and operate without noise, wear, or emissions.

[0071] Finally, it should be noted that the embodiments listed above are merely one or more specific manifestations of the technical solution of this invention. Their purpose is to clearly illustrate the concept, principle, and application of this invention through specific examples, and is by no means intended to limit the scope of protection of this invention to these specific embodiments. In fact, the true value of this invention lies in its proposed technical ideas and innovations, rather than its manifestations or implementation methods.

[0072] For those skilled in the art, after thoroughly reading and understanding the technical solution of this invention, they are fully capable of making various changes, modifications, or equivalent substitutions to the specific implementation of the invention based on their own professional knowledge and skills. These changes may include, but are not limited to: adjusting the range of technical parameters, optimizing the algorithm flow to improve efficiency, and replacing some technical components to achieve better compatibility or reduce costs. As long as these modified technical solutions substantially retain the technical features claimed by the original invention, that is, they can still achieve the core functions and effects of this invention, then these changes should be considered to fall within the scope of protection of the pending claims of this invention.

[0073] Furthermore, with the continuous progress and development of technology, new technical means and methods are constantly emerging, which provides ample space for further improvement and perfection of this invention. Therefore, the scope of protection of this invention should also include reasonable and foresightful improvements and extensions based on existing technology. As long as these improvements and extensions do not depart from the basic principles and core concepts of this invention, they should be considered equivalents of this invention and are equally protected by patent rights.

Claims

1. An energy-saving power supply system for a heat exchange station based on thermoelectric power generation, characterized in that, The system includes a heat exchange station system and a thermoelectric power generation system coupled thereto. The heat exchange station system includes a thermal power plant (1), a heat exchanger (15), a heat user (2), a primary network water inlet pressure gauge (7), a primary network water return pressure gauge (8), a secondary network water inlet pressure gauge (9), and a secondary network water return pressure gauge (10). The primary network water outlet of the thermal power plant (1) is connected to the primary network water inlet of the thermal power plant (1) in sequence via the primary network water inlet pressure gauge (7), the first inlet of the heat exchanger (15), the first outlet of the heat exchanger (15), and the primary network water return pressure gauge (8) to form a primary network water loop. The secondary network water outlet of the heat user (2) is connected to the secondary network water inlet of the heat user (2) in sequence via the secondary network water inlet pressure gauge (9), the second inlet of the heat exchanger (15), the second outlet of the heat exchanger (15), and the secondary network water return pressure gauge (10) to form a secondary network water loop. The thermoelectric power generation system includes a hot water diversion valve (16), a cold water diversion valve (17), and a thermoelectric generator (20). The thermoelectric generator (20) includes a hot water heat exchanger (21), a cold water heat exchanger (22), and a thermoelectric generator (23). The thermoelectric generator (23) is sandwiched between the hot water heat exchanger (21) and the cold water heat exchanger (22). The primary network water outlet of the thermal power plant (1) is connected to the inlet of the hot water heat exchanger (21) via the hot water diversion valve (16), and the outlet of the hot water heat exchanger (21) flows into the thermal power plant (1). The primary network water inlet of the heat user (2) is used to divert part of the primary network water to the hot water heat exchanger (21); the secondary network water outlet of the heat user (2) is connected to the inlet of the cold water heat exchanger (22) via the cold water diversion valve (17), and the outlet of the cold water heat exchanger (22) flows into the secondary network water inlet of the heat user (2), which is used to divert part of the secondary network water to the cold water heat exchanger (22). The primary network water flowing into the hot water heat exchanger (21) and the secondary network water flowing into the cold water heat exchanger (22) generate electricity by utilizing the temperature difference through the thermoelectric generator (23).

2. The energy-saving power supply system for a heat exchange station based on thermoelectric power generation according to claim 1, characterized in that, The heat exchange station system also includes a primary network water pump (3) and a secondary network water pump (4). The primary network water pump (3) is located between the primary network water outlet of the thermal power plant (1) and the first inlet of the heat exchanger (15). The secondary network water pump (4) is located between the secondary network water outlet of the heat user (2) and the second inlet of the heat exchanger (15).

3. The energy-saving power supply system for a heat exchange station based on thermoelectric power generation according to claim 1, characterized in that, The heat exchange station system also includes a primary network water flow meter (5) and a secondary network water flow meter (6). The primary network water flow meter (5) is located between the primary network water outlet of the thermal power plant (1) and the first inlet of the heat exchanger (15). The secondary network water flow meter (6) is located between the secondary network water outlet of the heat user (2) and the second inlet of the heat exchanger (15).

4. The energy-saving power supply system for a heat exchange station based on thermoelectric power generation according to claim 1, characterized in that, The heat exchange station system also includes a primary network water inlet thermometer (11) and a secondary network water inlet thermometer (13). The primary network water inlet thermometer (11) is located between the primary network water outlet of the thermal power plant (1) and the first inlet of the heat exchanger (15). The secondary network water inlet thermometer (13) is located between the secondary network water outlet of the heat user (2) and the second inlet of the heat exchanger (15).

5. The energy-saving power supply system for a heat exchange station based on thermoelectric power generation according to claim 1, characterized in that, The heat exchange station system also includes a primary network water return thermometer (12) and a secondary network water return thermometer (14). The primary network water return thermometer (12) is located between the first outlet of the heat exchanger (15) and the primary network water return pressure gauge (8), and the secondary network water return thermometer (14) is located between the second outlet of the heat exchanger (15) and the secondary network water return pressure gauge (10).

6. The energy-saving power supply system for a heat exchange station based on thermoelectric power generation according to claim 1, characterized in that, The thermoelectric power generation system also includes a hot water flow meter (18) and a cold water flow meter (19). The primary network water outlet of the thermal power plant (1) is connected to the inlet of the hot water heat exchanger (21) via the hot water flow meter (18) and the hot water diversion valve (16) in sequence. The secondary network water outlet of the heat user (2) is connected to the inlet of the cold water heat exchanger (22) via the cold water flow meter (19) and the cold water diversion valve (17) in sequence.

7. The energy-saving power supply system for a heat exchange station based on thermoelectric power generation according to claim 1, characterized in that, The hot water heat exchanger (21) adopts a partitioned hot water heat exchanger (21), and the cold water heat exchanger (22) adopts a partitioned cold water heat exchanger (22).

8. The energy-saving power supply system for a heat exchange station based on thermoelectric power generation according to claim 1, characterized in that, The thermoelectric generator (20) also includes an energy conversion module for converting the direct current generated by the thermoelectric generator (23) into alternating current and supplying power to electrical equipment.

9. The energy-saving power supply system for a heat exchange station based on thermoelectric power generation according to claim 1, characterized in that, The thermoelectric generator (23) is made of P-type bismuth telluride and N-type bismuth telluride materials.

10. The working method of the energy-saving power supply system for heat exchange stations based on thermoelectric power generation as described in any one of claims 1 to 9, characterized in that, Includes the following steps: Obtain the data from the primary water inlet pressure gauge (7) and the primary water return pressure gauge (8), and calculate the pipeline pressure difference A of the primary water circuit, specifically: The pipeline pressure difference A of the primary network water circuit = the data of the primary network water inlet pressure gauge (7) - the data of the primary network water return pressure gauge (8); Obtain the data from the secondary network water inlet pressure gauge (9) and the secondary network water return pressure gauge (10), and calculate the pipeline pressure difference B of the secondary network water circuit, specifically: The pipeline pressure difference B of the secondary network water circuit = the data of the secondary network water inlet pressure gauge (9) - the data of the secondary network water return pressure gauge (10); Determine whether the pipe pressure difference A of the primary water circuit is equal to the pipe pressure difference B of the secondary water circuit. If the determination result is yes, then maintain the current opening of the hot water diversion valve (16) and the cold water diversion valve (17). If the judgment result is negative, the opening of the hot water diversion valve (16) and the cold water diversion valve (17) is adjusted to make the water flow into the hot water heat exchanger (21) and the cold water heat exchanger (22) basically equal, so as to maintain a stable temperature difference between the two ends of the thermoelectric generator (23) for power generation.

Images