A one-tube double-effect structure design of TEG and heat pipe cooperation

Abstract

The application discloses a one-pipe double-effect structure design of TEG and heat pipe cooperation, comprising a heat pipe assembly, a TEG thermoelectric generator module and a phase change energy storage and heat dissipation unit. The heat pipe evaporation section is attached to the heating equipment of the elevator machine room, and the condensation section is divided into a first branch and a second branch: the first branch is connected to the hot end of the TEG module for thermoelectric generation, and the second branch is connected to the PCM phase change energy storage material and the heat dissipation fin for heat dissipation. The same heat pipe simultaneously undertakes two functions of temperature control and thermoelectric generation, and realizes the step-by-step utilization of heat energy - first generating electricity and then dissipating heat. The TEG array outputs 200 to 500 W direct current, and the temperature of the machine room is controlled below 35 DEG C without air conditioning, and the heat distribution ratio can be adjusted to optimize the power generation efficiency and temperature control effect. The structure design of the application is maintenance-free, and the service life exceeds 70,000 hours.

Description

Technical Field

[0001] This invention relates to the field of heat recovery and thermoelectric power generation technology, specifically to a dual-effect structure design that integrates heat pipe heat dissipation and TEG thermoelectric power generation, which is particularly suitable for waste heat recovery and temperature control in enclosed equipment rooms such as elevator machine rooms. Background Technology

[0002] In elevator machine rooms, equipment such as traction machines, frequency converters, and braking resistors continuously generate a large amount of heat during operation. Traditional solutions use air conditioning to maintain the machine room temperature within a safe range, which not only consumes a lot of electrical energy but also wastes recoverable heat energy.

[0003] Thermoelectric power generation technology is based on the Seebeck effect. When a temperature difference exists between the two ends of a thermoelectric module, charge carriers diffuse from the hot end to the cold end, generating a direct current in a closed loop. Bismuth telluride (Bi₂Te₃)-based thermoelectric materials have the highest thermoelectric figure of merit (ZT) in the temperature range of room temperature to 200°C, making them the most mature thermoelectric materials for commercial applications. However, the conversion efficiency of thermoelectric power generation systems is only 5% to 8%, making it difficult to economically and efficiently recover large amounts of waste heat when used alone.

[0004] A heat pipe is a highly efficient thermal element that utilizes the phase change process of the working fluid absorbing heat and vaporizing in the evaporation section, and releasing heat and liquefying in the condensation section to achieve heat transfer. The equivalent thermal conductivity of a heat pipe can reach [value missing].

[0005] With a strength of over 10,000 W / mK, which is more than 100 times that of pure copper, it can rapidly transfer large amounts of heat with minimal temperature difference.

[0006] Phase change energy storage materials (PCMs) absorb or release a large amount of latent heat at the phase change temperature point, and have the characteristics of high heat storage density and constant temperature during the heat absorption and release process.

[0007] The limitations of existing technology are:

[0008] 1. Heat pipe cooling and thermoelectric power generation are used independently, without forming a synergistic integrated solution. Heat pipes are only used for heat dissipation, wasting heat energy that could be used to generate electricity; thermoelectric power generation is only used for power generation, without solving the heat dissipation problem.

[0009] 2. Thermoelectric power generation systems require a stable temperature difference environment, but existing solutions are unable to maintain a stable temperature difference under varying operating conditions in elevator machine rooms, resulting in large fluctuations in power generation efficiency.

[0010] 3. The lack of a structural design that organically combines heat pipe heat conduction, thermoelectric power generation, and phase change energy storage makes it impossible to achieve the cascade utilization of thermal energy. Summary of the Invention

[0011] Purpose of the invention

[0012] The purpose of this invention is to provide a dual-effect structure design for TEG and heat pipe in synergy. By dividing the condenser section of the heat pipe into two branches that serve TEG power generation and PCM heat dissipation respectively, the same heat pipe can simultaneously undertake the functions of temperature control and thermoelectric power generation, realizing the cascade utilization of thermal energy—power generation first and then heat dissipation, significantly improving the thermal energy utilization rate.

[0013] Technical solution

[0014] This invention provides a dual-effect structure design for a TEG and heat pipe working together, comprising:

[0015] (a) Heat pipe assembly

[0016] The heat pipe assembly consists of an evaporation section and a condensation section. The evaporation section is attached to the surface of the heat-generating equipment in the elevator machine room (traction machine housing, braking resistor heat dissipation surface, or inverter heat dissipation surface), ensuring good thermal contact through thermal grease or a thermally conductive silicone pad. The heat pipes are copper-water heat pipes (operating temperature 30 to 150°C) or stainless steel-ethanol heat pipes, with an equivalent thermal conductivity of up to 10,000 W / m².

[0017] mK and above.

[0018] The heat pipe condensation section is divided into a first branch and a second branch, which is the core structural innovation of this invention. The first branch connects to the hot end of the TEG thermoelectric generator module, and the second branch connects to the phase change energy storage heat dissipation unit.

[0019] (ii) TEG thermoelectric generator module

[0020] The TEG thermoelectric generator module is located at the first branch of the heat pipe condenser section. The hot end of the TEG module is thermally connected to the first branch of the heat pipe condenser section, and thermal contact is ensured by thermal grease. The cold end of the TEG module is thermally connected to an independent heat sink, which is either a miniature heat pipe heat sink or a liquid-cooled plate, to maintain the TEG cold end temperature below 35°C.

[0021] The TEG modules use bismuth telluride (Bi2Te3)-based thermoelectric materials. Each module measures 40mm×40mm or 56mm×56mm and contains 200 to 250 PN junction pairs. The TEG modules are arranged in an array on the surface of the first branch of the heat pipe's condenser section. Each array consists of 20 to 30 TEG modules connected in series and parallel. Under a temperature difference of 150°C, the open-circuit voltage of a single module is approximately 10V, the load power is approximately 12 to 23W, and the total output power of the array is 200 to 500W.

[0022] (III) Phase Change Energy Storage Heat Dissipation Unit

[0023] The phase change energy storage and heat dissipation unit is located at the second branch of the heat pipe condensation section and includes a phase change energy storage material (PCM) and heat dissipation fins. The PCM material is paraffin-based or polymer-based, with a phase change temperature of 35 to 55°C and a latent heat value greater than 150 kJ / kg. The PCM material covers the outer perimeter of the second branch of the heat pipe condensation section. During peak elevator operation (when the traction machine's peak thermal power can reach 5 to 15 kW), it absorbs a large amount of latent heat and stores it. During off-peak hours, it slowly releases the heat outside the machine room through the heat dissipation fins and forced air cooling.

[0024] (iv) Regulation of heat distribution

[0025] The heat distribution ratio between the first and second branches of the heat pipe condenser section is adjustable. By adjusting the heat dissipation area ratio of the first and second branches, or by adding controllable valves to regulate the working fluid flow distribution, the TEG module's hot-end temperature is maintained within the optimal power generation temperature range of 60 to 90°C, while ensuring effective temperature control in the data center. When the data center temperature rises, the heat distribution ratio of the second branch is increased to enhance heat dissipation; when the TEG hot-end temperature is low, the heat distribution ratio of the first branch is increased to improve power generation efficiency.

[0026] (V) Working principle of one pipe with two effects

[0027] The heat pipe assembly performs two functions simultaneously:

[0028] The primary function is temperature control: it quickly removes heat from the heat-generating equipment in the computer room, and after peak shaving and valley filling by PCM phase change energy storage, it is discharged outside the computer room through heat dissipation fins and forced air cooling, keeping the computer room temperature below 35℃.

[0029] The second function is power generation: it provides a stable heat source for the hot end of the TEG thermoelectric generator module, while the cold end of the TEG is kept at a low temperature by an independent heat sink to ensure stable thermoelectric power generation.

[0030] This "one pipe, two effects" design creates a synergistic system-level solution where the heat pipe, TEG, and phase change material work together: the heat pipe rapidly removes heat from the equipment → some of the heat is converted into electricity via the TEG → the remaining heat is stored in the PCM and dissipated by air cooling → achieving tiered utilization of thermal energy (generating electricity first, then dissipating it). Thermal energy utilization is improved by more than 30% compared to solutions using separate temperature control or separate power generation.

[0031] Beneficial effects

[0032] 1. Dual-Effect Innovation in One Heat Pipe: The same heat pipe serves two functions simultaneously: temperature control and thermoelectric power generation. This is the core innovation of the present invention, which distinguishes it from all existing solutions.

[0033] 2. Cascaded utilization of thermal energy: First, a portion of the thermal energy is converted into electrical energy (200-500W DC) through the TEG module, and then the remaining heat is discharged through the PCM and air cooling, increasing the thermal energy utilization rate by more than 30%.

[0034] 3. Stable temperature difference power generation: The heat pipe provides a stable heat source for the hot end of the TEG, and the independent radiator maintains a low temperature at the cold end, ensuring a stable temperature difference of no less than 100°C under the variable operating conditions of the elevator, resulting in stable power generation efficiency.

[0035] 4. Eliminate air conditioning energy consumption: With the machine room temperature controlled below 35℃, no additional air conditioning is required, saving 3,000 to 8,000 kWh of air conditioning electricity per elevator per year.

[0036] 5. Maintenance-free and long lifespan: The TEG module has no moving parts, no noise, and requires no maintenance. The heat pipe and PCM are also maintenance-free, and the system has a lifespan of over 70,000 hours (approximately 10 years).

[0037] 6. Intelligent adjustment: The heat distribution ratio is adjustable. The PLC controller automatically optimizes the temperature control and power generation based on the room temperature and TEG power generation efficiency, achieving optimal coordination between temperature control and power generation. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall structure of the single-tube dual-effect device of the present invention;

[0039] Figure 2 Detailed diagram of the branch structure of the heat pipe condenser section;

[0040] Figure 3 This is a schematic diagram of the TEG module array arrangement;

[0041] Figure 4 This is a schematic diagram of the PCM phase change energy storage heat dissipation unit structure;

[0042] Figure 5 This is a schematic diagram of the heat distribution and adjustment mechanism;

[0043] Figure 6 This is a flowchart illustrating the working principle of a single pipe with dual effects. Detailed Implementation

[0044] Example 1: Standard single-tube dual-effect structure

[0045] Heat pipe assembly: 6 copper-water heat pipes, evaporation section length 150mm, condensation section total length 200mm (first branch 80mm, second branch 120mm). The evaporation section is fitted into the traction machine casing.

[0046] TEG array: 25 Bi2Te3 modules (56mm×56mm), 5 groups in parallel × 5 modules in series, arranged in the first branch of the heat pipe condenser section. TEG hot end temperature 75-85℃, cold end temperature 30-35℃, temperature difference approximately 150℃, total output power 300W.

[0047] PCM cooling unit: Paraffin-based PCM (phase change temperature 45℃, latent heat 180 kJ / kg), 15kg filling, covering the second branch of the heat pipe condenser section. Aluminum heat sink fins (fin spacing 3mm), 2 x 120mm DC 24V axial fans (airflow 200CFM).

[0048] Heat distribution: The heat dissipation area ratio of the first branch to the second branch is approximately 2:3. The TEG hot end temperature is maintained in the optimal temperature range of 75-85℃, and the computer room temperature is controlled at 32-35℃.

[0049] Actual test data: When the traction machine's thermal power is 8kW, the TEG array outputs 300W DC power (thermoelectric conversion efficiency of about 3.75%), the PCM's thermal storage power is 5kW during peak hours and 3kW during off-peak hours, and the computer room temperature is stable at 33℃, requiring no air conditioning.

[0050] Example 2: High-power single-tube dual-effect structure

[0051] Heat pipe assembly: 10 stainless steel-ethanol heat pipes, evaporation section length 200mm, condensation section total length 280mm (first branch 120mm, second branch 160mm).

[0052] TEG array: 30 high-power Bi2Te3 modules, with a total output power of 500W.

[0053] PCM cooling unit: Polymer-based PCM (phase change temperature 50℃, latent heat value 200 kJ / kg), 25kg filling. 4 x 120mm DC 24V axial fans.

[0054] Actual measured data: When the traction machine's thermal power is 15kW, the TEG array outputs 500W DC power, the PCM's peak thermal storage power is 10kW, and the machine room temperature remains stable at 34℃.

[0055] Example 3: Adjustable heat distribution type

[0056] Based on Example 1, a miniature solenoid valve is added to control the working fluid flow distribution between the two branches of the heat pipe condenser section. The PLC controller automatically adjusts the valve opening based on data from the TEG hot-end temperature sensor and the machine room temperature sensor: when the TEG hot-end temperature is below 70°C, the flow distribution to the first branch is increased; when the machine room temperature is above 33°C, the flow distribution to the second branch is increased. This achieves optimal dynamic coordination between temperature control and power generation.

Claims

1. A dual-effect structure design of a TEG and heat pipe working together, characterized in that, include: The system comprises a heat pipe assembly, a TEG thermoelectric generator module, and a phase change energy storage and heat dissipation unit. The heat pipe assembly includes an evaporation section and a condensation section. The evaporation section is attached to the surface of the heating equipment in the elevator machine room, and the condensation section is divided into a first branch and a second branch. The first branch is connected to the hot end of the TEG thermoelectric generator module, and the second branch is connected to the phase change energy storage and heat dissipation unit. The same heat pipe simultaneously performs temperature control and thermoelectric power generation functions, realizing the cascade utilization of thermal energy—generating power first and then dissipating heat.

2. The dual-effect structure design of TEG and heat pipe synergy according to claim 1, characterized in that, The heat pipe assembly uses copper-water heat pipes or stainless steel-ethanol heat pipes with an equivalent thermal conductivity of over 10,000 W / (m·K) and an operating temperature of 30 to 150°C. The evaporation section is attached to the traction machine housing, the braking resistor heat dissipation surface, or the inverter heat dissipation surface with thermal grease or thermal silicone pads to ensure good thermal contact.

3. The dual-effect structure design of TEG and heat pipe synergy according to claim 1, characterized in that, The TEG thermoelectric power generation module is located at the first branch of the heat pipe condensation section, with its hot end thermally connected to the first branch and its cold end thermally connected to an independent heat sink; the independent heat sink is a miniature heat pipe heat sink or a liquid-cooled plate, used to maintain the TEG cold end temperature below 35°C.

4. The dual-effect structure design of TEG and heat pipe synergy according to claim 3, characterized in that, The TEG thermoelectric power generation module uses bismuth telluride (Bi2Te3) based thermoelectric material. The specifications of a single module are 40mm×40mm or 56mm×56mm, containing 200 to 250 pairs of PN junctions. The TEG modules are arranged in an array on the surface of the first branch, consisting of 20 to 30 modules connected in series and parallel. Under a temperature difference of 150℃, the total output power of the array is 200 to 500W DC.

5. The dual-effect structure design of TEG and heat pipe synergy according to claim 1, characterized in that, The phase change energy storage heat dissipation unit is located at the second branch of the heat pipe condensation section and includes a phase change energy storage material and heat dissipation fins. The phase change energy storage material is paraffin-based or polymer-based, with a phase change temperature of 35 to 55°C and a latent heat value greater than 150 kJ / kg, and is wrapped around the second branch.

6. The dual-effect structure design of TEG and heat pipe synergy according to claim 5, characterized in that, The phase change energy storage and heat dissipation unit absorbs latent heat through phase change energy storage materials during peak elevator operation periods and slowly releases heat outside the machine room through heat dissipation fins and forced air cooling during off-peak periods, keeping the machine room temperature below 35°C without the need for additional air conditioning.

7. The dual-effect structure design of TEG and heat pipe synergy according to claim 1, characterized in that, The heat distribution ratio between the first and second branches of the heat pipe condensation section is adjustable. By adjusting the heat dissipation area ratio of the two branches or by adding a controllable valve to adjust the working fluid flow distribution, the hot end temperature of the TEG module is maintained in the optimal power generation temperature range of 60 to 90°C.

8. The dual-effect structure design of TEG and heat pipe synergy according to claim 7, characterized in that, When the room temperature rises, the heat distribution ratio of the second branch is increased to enhance heat dissipation; when the TEG hot end temperature is low, the heat distribution ratio of the first branch is increased to improve power generation efficiency. The heat distribution is automatically optimized by the PLC controller based on the room temperature and TEG power generation efficiency.

9. The dual-effect structure design of TEG and heat pipe synergy according to claim 1, characterized in that, The heat pipe, TEG thermoelectric generator module, and phase change energy storage material form a synergistic system-level solution: the heat pipe quickly removes heat from the equipment, part of the heat is converted into 200 to 500W DC electricity by TEG, and the remaining heat is dissipated through phase change energy storage and air cooling. The thermal energy utilization rate is more than 30% higher than that of individual temperature control or individual power generation solutions.

10. The dual-effect structure design of TEG and heat pipe synergy according to claim 1, characterized in that, The TEG module has no moving parts, no noise, and requires no maintenance. The heat pipe and phase change energy storage material are also maintenance-free, and the system has a service life of over 70,000 hours.

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