GB2614682A - Personal thermal comfort device based on Peltier effect, and thermal management method - Google Patents

Abstract

A personal thermal comfort device based on a Peltier effect, and a thermal management method. The device comprises a thermoelectric module, a heat dissipation fan, an external packaging module, a micro-blower, and a micro-hose network; heat dissipation plates are attached to the warm and cold sides of the thermoelectric module, respectively; the thermoelectric module and the heat dissipation fan form an integrated structure by means of the external packaging module provided with a channel; one end of the integrated structure is connected to the micro-blower, and the other end of the integrated structure is connected to the micro-hose network; the micro-blower provides a cold or warm airflow and the micro-hose network guides same to a special garment, so as to provide a required heat source or cold source for the whole human body. The specific thermoelectric module, heat dissipation fan and heat dissipation plates are selected and combined into a detachable, portable thermoelectric conversion device, the micro-blower is selected to send cold energy or heat energy to the special garment, the air supply temperature is set according to a thermal comfort requirement of the human body, the voltage of the thermoelectric conversion device is adjusted by means of a single-neuron PID controller, and the thermal comfort of the human body in a local microenvironment of a building is improved. The whole device has the advantages of portability, excellent energy efficiency and controllable temperature. In combination with a central heating, ventilation, and air conditioning system of a building, a local thermal environment can be established, the personal thermal comfort is improved, and the overall energy consumption of the building is reduced.

Description

PERSONAL THERMAL COMFORT DEVICE BASED ON PELTIER EFFECT, AND

THERMAL MANAGEMENT METHOD

TECHNICAL FIELD

The present disclosure relates to a personal thermal comfort device and a thermal management method based on a Peltier effect, and belongs to the technical field of thermoelectric conversion.

BACKGROUND

In order to meet the needs of modern wars, the earliest personal thermal management device was developed to solve the problems of operators such as rapid energy consumption, inattention and slow brain reaction due to heat stress in high-temperature environment. At present, there are two types of personal thermal management clothing, namely, personal thermal management clothing heating or cooling by a liquid or air, and personal thermal management clothing heating or cooling through the chemical reaction of a phase change material.

With the research on equipment for heating and cooling through thermoelectric conversion at home and abroad, thermoelectric cooling has rapidly become a practical technology applicable to various types of electronic equipment. The equipment in the current market is compact, efficient, and has an advanced internal structure. In this context, various types of thermoelectric modules based on the Peltier effect have developed rapidly. In order to keep the temperature of some electronic components stable, a heat sink and a mini heat dissipation fan are often combined for cooling the electronic components to ensure the stability and accuracy of the electronic components.

The heating, ventilation and air conditioning (HVAC) system of buildings can be combined to expand the indoor temperature regulation range. In 2018, the University of Colorado Boulder and the Laboratory of Thermo-Fluid Science and Engineering of Xi'an Jiaotong University jointly developed a personal thermal management device. The personal thermal management device integrates a heat sink, a thermoelectric module, and a mini heat dissipation fan into a simple thermoelectric conversion unit (TECU), but it has an insignificant effect and a too small and uncontrollable temperature adjustment range.

SUMMARY

The present disclosure provides a personal thermal comfort device and thermal management method based on a Peltier effect, aiming to solve the problems of large energy consumption and poor thermal comfort in existing buildings. The present disclosure maximizes the energy efficiency of a core assembly and maximizes an adjustable temperature range. According to simulation and experimental data, the present disclosure determines a thermoelectric module and a mini heat dissipation fan, determines the distribution and structure of fins of heat sinks, determines a main packaging structure and air inlet and outlet layouts of the device, to form a portable thermoelectric conversion unit (TECU) with optimal energy efficiency. The present disclosure integrates a micro-blower and designs a hose layout in a garment, thereby designing the temperature-controllable personal thermal comfort device.

The present disclosure adopts the following technical solutions. The personal thermal comfort device based on the Peltier effect includes a thermoelectric module, a heat dissipation fan, an external packaging module, a micro-blower, and a micro-hose network, where a hot side and a cold side of the thermoelectric module are respectively attached with heat sinks; the thermoelectric module and the heat dissipation fan are integrated into a TECU by the external packaging module with a channel; the TECU has one end connected to the micro-blower and an other end connected to the micro-hose network; and the micro-blower provides a hot or cold air flow to a garment with the micro-hose network, to provide a heat or cold source to a whole human body.

Further, the thermoelectric module has a three-layer structure, including an intermediate layer composed of a bismuth telluride thermocouple and a deflector connected in series, and alumina ceramic layers on two sides of the intermediate layer.

Further, the heat dissipation fan is mated with the thermoelectric module in terms of size, and is provided with multiple blades Further, the heat sinks include a hot-side heat sink and a cold-side heat sink; the hot-side heat sink is made of red copper, and is provided with straight-through fins; and the cold-side heat sink is made of aluminum or copper, and is provided with one row, four rows or more than four rows of dense straight-through fins with an optimal thickness of 0.5-1.5 mm and an optimal spacing of 0.5-1.5 mm.

Further, the hot-side heat sink has an overall size of 40 mm * 40 mm * 11 mm, a base thickness of 3 mm, and is provided with 25 fins, each with a thickness of 0.5 nun, and the cold-side heat sink is provided with four rows of 0.8 mm thick fins arranged with a spacing of 0.6 mm.

Further, the external packaging module includes a main frame package, and an external air inlet part, and a back cover carrying an air outlet part respectively communicated with two sides of the main frame package; the external air inlet part includes a round-hole cylindrical air inlet 4, a rectangular connector 5 between the main frame package and the round-hole cylindrical air inlet, a smooth surface 6, reserved holes 7, and an internal air inlet 8, the round-hole cylindrical air inlet 4 is connected to the connector 5 between the main frame package and the round-hole cylindrical air inlet through the smooth surface 6; the reserved holes 7 are provided at two ends of a junction between two adjacent sides of the connector 5 between the main frame package and the round-hole cylindrical air inlet to serve as wire positions for the thermoelectric module; and the internal air inlet 8 is provided at a bottom of a side of the connector 5 between the main frame package and the round-hole cylindrical air inlet; the main frame package is a shell structure, a top end of the main frame package is provided with a round fan exhaust outlet 12, left and right sides of the main frame package are symmetrically provided with second hot-side heat sink vents 16; a back side of the main frame package is sequentially provided with a fan wire hole 13, a first hot-side heat sink vent 15, two thermoelectric module wire holes 14 arranged horizontally and symmetrically, and a counterpart 17 of the internal air inlet 8 from top to bottom; a front side of the main frame package is an open end side defined as a front shell 10; an internal space of the main frame package is divided into an upper space and a lower space by a partition 11 between the hot-side heat sink and the heat dissipation fan; the upper space is provided with a main heat dissipation chamber of the hot-side heat sink and the fan exhaust outlet; and the lower space is provided with a main heat exchange chamber of the cold-side heat sink; and the back cover carrying the air outlet part includes a back cover, a smooth connection surface 20, and a round-hole cylindrical air outlet 21; the back cover has a double-layer structure with a lateral section forming an L-shaped shell; one side of a vertical part of the L-shaped shell is clamped into the front shell 10; and an other side of the vertical part of the L-shaped shell forms a protruding rectangular end, connected to the round-hole cylindrical air outlet 21 through the smooth connection surface 20, at a bottom; and the other side of the vertical part of the L-shaped shell is provided with a counterpart 22 of the first hot-side heat sink vent 15.

Further, the micro-hose network has a Y-shaped topology or an 0-shaped topology.

The thermal management method of the personal thermal comfort device based on the Peltier effect includes the following steps: 1) integrating the thermoelectric module with the heat sinks and the heat dissipation fan to form the TECU, and packaging the TECU by the external packaging module, 2) guiding, by a micro-air pump, air through a pipe to pass through the TECU for heat exchange, and sending the air after the heat exchange into the micro-hose network embedded in a wearable garment through a pipe, 3) sending an expected temperature of the TECU outlet to a single-neuron proportional integral differential (PID) controller, acquiring a control output by the single-neuron PID controller; and 4) adjusting input voltage of the thermoelectric module by means of a pulse width modulation (PWM) according to control output given by the single-neuron PID controller.

Further, in step 3), the single-neuron PID controller is built with a single-neuron PID algorithm, and a single-neuron PID control formula is Au(k)=K(co1x,+co.,x2+co,x,) where, An(k) denotes the increment of control output, K denotes a neuron gain coefficient; xi=e(k)-e(k-1), x2=e(k), x3=e(k)-2e(k-1)+e(k-2) are three neuron input signals; e(k)=r(k)-n(k) denotes the temperature deviation signal at the kth sampling period; r(k) and n(k) denote the expected temperature and actual temperature of the TECU outlet respectively; co, (i=1,2,3) denotes a weight factor of a corresponding input xi; the weighting factors in the formula are adjusted online by the supervised Hebbian learning rule, to improve the adaptive performance against system uncertainty; and the learning rule is as follows: a)1(k+1)=ifi1(k)+qi,e(k)u(k)(e(k)+ Ae(k)) co, (k +1)=0.)2(k)+17,e(k)n(k)(e(k)+ Ae(k)) (o (k +1)= cv.,(k)+ it,e(k)n(k)(e(k)+ Ae(k)) where, qp, ij, and ?id denote learning rates of proportional, integral and differential components respectively; Ae(k)=e(k)-e(k-1), and u(k)=u(k-1)+Azi(k) denotes an output of the single-neuron PID controller to regulate the input voltage signal of the thermoelectric module Further, in step 4), according to the above output signal u(k), different voltage values are output by means of PWM to control the thermoelectric module to generate different power; a PWM module and an external power are introduced; PWM signals of different duty cycles sent by a microcontroller are utilized to modulate the external power, such that different input voltages are obtained for the thermoelectric module.

The present disclosure has the following technical effects.

The personal thermal comfort device has a total of six components, which are respectively described as follows. 1. Thermoelectric module based on a Peltier effect. The thermoelectric module has a three-layer structure, including an intermediate layer composed of a bismuth telluride thermocouple and a deflector connected in series, and alumina ceramic layers on two sides of the intermediate layer. Bismuth telluride is a widely used thermoelectric material because of its natural anisotropy. The alumina ceramic layers have desired thermal conductivity, mechanical strength and high temperature resistance. The thermoelectric module provides a cold source and has a desired effect for cooling in summer.

2. Heat dissipation fan. The heat dissipation fan is mated with the thermoelectric module in size. The heat dissipation fan is provided with multiple blades, and has high power, high speed, and large air volume. A temperature difference AT between the hot side and the cold side of the thermoelectric module is proportional to an input voltage (AT cc V) That is, a greater voltage indicates a greater temperature difference AT. Therefore, when the hot-side heat sink is fully cooled, the cooling effect on the cold side is very good, and the temperature on the cold side can reach 7.8°C.

3. Cold-side heat sink and hot-side heat sink. In order to reduce the temperature of the cold side, the hot side needs full heat dissipation. The hot-side heat sink made of red copper has an overall size of 40 mm * 40 mm * 11 mm and a base thickness of 3 mm, and is provided with 25 fins, each being 0.5 mm thick. In case of an input voltage of 4.5 V and a current of 2.37 A, the air drops to a temperature of 30.5°C after passing through the hot-side heat sink. The aluminum cold-side heat sink stores cold energy. The cold-side heat sink is provided with four rows of fins, with a thickness of 0.8 mm and a spacing of 0.6 mm. The cold-side heat sink has little influence on the speed of the external air flow and can store a large amount of cold energy.

4. External packaging module. The thermoelectric module, the heat sink and the heat dissipation fan are packaged to form a simple TECU to achieve the purpose of modular integration. The external packaging module is provided with the external air inlets, outlet, wire holes, and heat vents. The TECU is portable and detachable through the external packaging module. The external air flow circulates in the staggered L-shaped shell, such that the energy stored at the cold side is fully taken away by the external air flow.

5. Micro-blower. The micro-blower is configured to provide the external air flow to the personal thermal comfort device, with a large air volume and an adjustable air speed.

6. Micro-hose network. The cold energy generated by the thermoelectric module is stored in the packaging shell through the cold-side heat sink. The external air flow provided by the micro-blower blows the cold air to the special garment with the micro-hose network to cool the human body and improve the human comfort. The chest and back of the human body are sensitive to temperature. The Y-shaped topology or the 0-shaped topology mainly passes through the chest and back of the human body, thus providing an obvious cooling effect.

The present disclosure aims to solve the problems of large energy consumption and poor personal thermal comfort in the current heating, ventilation and air conditioning (HVAC) system. The personal thermal management method can improve the personal thermal comfort, and can expand the temperature setting range of the central air conditioner to effectively reduce the energy consumption of the air conditioner. Compared with some existing personal thermal management methods, the present disclosure designs the single-neuron PID control algorithm, which can effectively improve human comfort and has great application potential. The present disclosure realizes the self-adaptive and self-organizing functions of system structure, parameters and uncertainties

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a Peltier effect.

FIG. 2 is a structure diagram of a thermoelectric module.

FIG. 3 is an external structure diagram of a heat dissipation fan.

FIG. 4 is a structure diagram of a hot-side copper heat sink.

FIG. 5 is a structure diagram of a cold-side aluminum heat sink.

FIG. 6 is a structure diagram of an external air inlet part.

FIG. 7 is a structure diagram of a main frame package.

FIG. 8 is a structure diagram of a back cover carrying an air outlet part.

FIG. 9 shows a layout of a hose network in a garment: (a) Y-shaped, and (b) 0-shaped.

FIG. 10 is a schematic diagram of a hot-side heat sink and a cold-side heat sink attached to a thermoelectric module.

FIG. 11 is an overall schematic diagram of a thermoelectric conversion unit (TEC U).

FIG. 12 is a schematic diagram of a personal thermal comfort device.

FIG. 13 is a flowchart of a single-neuron PlD control algorithm.

FIG. 14 is a flowchart of adjusting TECU outlet temperature to improve personal thermal comfort.

Reference Numerals: 1. first alumina ceramic layer; 2. intermediate layer; 3. second alumina ceramic layer; 4. round-hole cylindrical air inlet; 5. rectangular connector between main frame package and round-hole cylindrical air inlet; 6. smooth surface; 7. reserved hole; 8. internal air inlet; 9. side shell; 10. front shell; 11. partition between hot-side heat sink and heat dissipation fan; 12. round fan exhaust outlet; 13. fan wire hole; 14. wire hole; 15. first hot-side heat sink vent; 16. second hot-side heat sink vent; 17. counterpart of internal air inlet 8; 18. top end of vertical part of L-shaped shell; 19. back end of vertical part of L-shaped shell; 20. smooth connection surface; 21. round-hole cylindrical air outlet; and 22. counterpart of first hot-side heat sink vent 15.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The personal thermal comfort device based on the Peltier effect can realize cooling in summer and heating in winter. When the personal thermal comfort device is configured to cool in summer, it mainly includes the following components.

(1) Thermoelectric module. The thermoelectric module is based on the Peltier effect, and meets the size, voltage, power, operating temperature and other indicators required by the personal thermal comfort device.

(2) Heat dissipation fan. It matches the size of the thermoelectric module and meets the volume, power, air speed and other indicators required by the personal thermal comfort device.

(3) Hot-side heat sink and cold-side heat sink. The materials, fin layouts and sizes of the heat sinks on two sides of the thermoelectric module are determined by making geometric models of the heat sinks by UG software, and performing computational fluid dynamics (CFD) simulation and optimization on the heat dissipation effects by Fluent software, and determining the parameters according to optimization results.

(4) External packaging module. According to the sizes of the components (1) to (3), the packaging of the personal thermal comfort device is realized through three-dimensional (3D) printing, and meets the thermal management indicators of portability, detachability, and energy efficiency.

(5) Micro-blower. It is provided outside the personal thermal comfort device and provides external air flow through a hose to meet the portability, power, air volume and other indicators.

(6) Micro-hose network. It meets the optimal energy efficiency indicator of the personal thermal comfort device.

In the component (1), a thermocouple is composed of N-and P-type semiconductor materials. When the thermocouple is connected to a direct current (DC), heat absorption and heat release occurs at the junction of the thermocouple due to different directions of the DC. This is the Peltier effect, as shown in FIG. 1.

The thermoelectric module based on the Peltier effect has a three-layer structure (FIG. 2), including first and second alumina ceramic layers (as shown in FIG. 1 and FIG. 3) on two sides, and an intermediate layer 2 composed of the bismuth telluride thermocouple and a deflector (with high thermal and electric conductivity) in series (FIG. 2). In the personal thermal comfort device, the thermoelectric module meets the following requirements: length * width * thickness = 40 * 40 * (3 -4) mm; working current less than 12 A; rated voltage less than 24 V; maximum power: 80-150W; and working temperature: -55°C to 80°C.

Three types of satisfactory thermoelectric modules based on the Peltier effect are compared, namely ZT8-12-F1-4040, TEC1-12706, and TEC1-12710. Among them, the TEC1-12710 thermoelectric module has a maximum cooling power of 120 W. The temperature difference between the two sides is above 58°C, and the lowest temperature of the cold side measured is 7.2°C, which can provide sufficient cold source for the device. The TEC1-12710 thermoelectric module has an external size of 40 * 40 * 3.4 mm, an internal resistance of 1.2-1.5 SI, a working current of EMAX = 10 A (when starting under VMAX 15), a rated voltage of DC 12 V (VMAX = 15.5 V), and a working ambient temperature of -55°C to 83°C. These parameters meet the design requirements.

In the component (2), in order to achieve compact structure and easy packaging, the size of the heat dissipation fan, L * W = 40 * 40 mm, matches with the thermoelectric module. Other parameters of the heat dissipation fan are as follows: DC voltage 12 V; current less than 1 A; fan speed greater than 10,000 rpm; and operating humidity: 45% to 85%. The heat dissipation fan has the shape structure shown in FIG. 3.

Three types of heat dissipation fans, namely LFFAN-LFS0412SL (DC: 12 V; 0.30 A), TELTA-AFB0412SHB (DC: 12 V; 0.35 A), and SAN ACE40-9GV0412P3J11 (DC: 12 V; 0.60 A) are compared. Among them, the TELTA-AFB0412SHB (DC: 12 V; 0.35 A) heat dissipation fan is provided with seven blades, with an external size of 40 * 40 * 15 mm. It is powered by 12 V DC and can operate at a relative humidity of 45% to 85%. It has a sufficient heat dissipation air volume (14.83 cfm) and air pressure, low working noise, and a speed of 11,000 rpm. These parameters meet the design requirements.

In the component (3), the temperature difference AT on two sides of the thermoelectric module is proportional to the input voltage (aT ocV). In summer, the thermoelectric module stores energy on the cold side and dissipates heat on the hot side. The hot-side heat sink and the cold-side heat sink are designed as follows.

The main objective of the hot-side heat sink is to cool down quickly and fully. The hot-side heat sink is made of red copper and is provided with straight-through fins. Other parameters of the hot-side heat sink are as follows: overall size 40 mm * 40 mm * 11 mm, base thickness 3 mm; and 25 fins, each being 0.5 mm thick. The structure of the hot-side heat sink is shown in FIG. 4.

The cold side needs to store enough cold energy, and its topology and size are the key factors. The parameters (size and fin layout) of the cold-side heat sink are optimized through fluid dynamics (CFD) simulation. The geometric model of the heat sink is made by UG software, and CFD simulation and optimization are performed on the heat dissipation effect by Fluent software. The parameter optimization involves the fin layout, thickness and spacing of the heat sink. The fin layout includes one row, four rows, and more than four rows of dense straight-through fins. After optimization, the fin thickness is 0.5-1.5 mm, and the spacing is 0.5-1.5 mm. The objective is to optimize the energy storage effect of the cold side. The results show that the heat sink with four rows of fins, 0.8 mm thick and 0.6 mm spaced can minimize the air temperature at the air outlet. By comparison, the energy storage effects of aluminum and copper heat sinks are not different. Considering the cost, the aluminum heat sink shown in FIG. 5 is selected, with the overall size of 40 mm * 40 mm * 11 mm.

In the component (4), acrylonitrile butadiene styrene (ABS) consumables are selected through 3D printing. The external packaging module includes three parts: an external air inlet part, a main frame package part, and a back cover carrying an air outlet part.

(1) As shown in FIG. 6, the external air inlet part is described as follows: A round-hole cylindrical air inlet 4 has an internal diameter of 7 mm, an external diameter of 11 mm, a wall thickness of 2 mm, and a cylindrical length of 13 mm. The round-hole cylindrical air inlet is inclined to one side, 8 mm away from a center.

A connector 5 between the main frame package and the round-hole cylindrical air inlet has a total width of 8.5 mm, a wall thickness of 2 mm, and is hollow inside to save materials.

A smooth surface 6 has a wall thickness of 2 mm.

Reserved holes 7 with a diameter of 3.2 mm, a distance of 5.5 mm from an edge and a depth of 6 mm are provided at two ends of the connector between the main frame package and the round-hole cylindrical air inlet, and are served as reserved wire positions of the thermoelectric module.

An internal air inlet 8 runs through the connector 5 between the main frame package and the round-hole cylindrical air inlet, and connects the round-hole cylindrical air inlet 4 and the smooth surface 6. The internal air inlet has a length of 32 mm, a width of 9 mm, and is tangent to a semi-arc with a diameter of 9 mm on either side. The internal air inlet is inclined to the same side as the round-hole cylindrical air inlet, and is 2.8 mm from a bottom and 3 mm from an edge.

(2) The main frame package is shown in FIG. 7. The main frame package includes two parts, namely, an upper space and a lower space. The upper space is provided with a main heat dissipation chamber of the hot-side heat sink and a fan exhaust outlet, and the lower space is provided with a main heat exchange chamber of the cold-side heat sink. The specific parameters are as follows: The main frame package has a size of 47 mm * 47 mm * 50 mm. Other parameters include: side shell 9: left and right wall thickness 3 mm; front shell 10: upper and lower wall thickness 2.8 mm, partition between the hot-side heat sink and the heat dissipation fan 11 2 mm thick, 29.3 mm from a bottom, and 18.7 mm from a top; fan exhaust outlet 12: 38 mm from a top; fan wire hole 13: 12 mm from a side, 9.5 mm from a center to the partition 11, and side length 7 mm; thermoelectric module wire holes 14 5.5 mm from a side, 15.8 mm from a bottom, symmetrical on two sides; first hot-side heat sink vent 15: 34 mm long and 10 mm wide, close to a lower center of the partition 11; second hot-side heat sink vents 16: 38 mm long and 10 mm wide; with four arc-shaped corners; as high as the first hot-side heat sink vent 15; located in a center of a side wall; and symmetrical on two sides; and counterpart 17 of the internal air inlet 8: the same as the internal air inlet 8.

(3) The back cover carrying an air outlet part is shown in FIG. 8. Considering the material hardness and structural stability, the back cover is designed as a double-layer shell, which fits a groove of the main frame package. Two walls of the back cover each have a thickness of 2.5 mm, and a hollow chamber of the back cover has a width of 8 mm. The design of a round-hole cylindrical air outlet 21 is the same as that shown in FIG. 7. The round-hole cylindrical air outlet is inclined to a side opposite to that the internal air outlet and inlet are inclined to, to make the air return and facilitate full heat exchange. In this way, the cold energy generated by the thermoelectric module is blown to the tree-shaped pipe. The dimensional parameters are as follows: Top end (one side) of a vertical part of an L-shaped shell 18: wall thickness 2.8 mm (the same as the front shell 10); back end (the other side) of the vertical part of the L-shaped shell 19: wall thickness 2.5 mm; and smooth connection surface 20: thickness 2 mm; and counterpart 22 of the first hot-side heat sink vent 15: the same as the first hot-side heat sink vent 15, with a semicircular angle.

In the component (5), the micro-blower provides air flow to take and make the cold energy flow to the whole body through the micro-hose network. The micro-blower meets the requirements of power, air volume, volume and other indicators. The specific parameters are as follows: adjustable air speed 15-30 m/s; DC voltage: 24-36 V; power: 50-100 W; air pressure: 5-10 KPa; and size: 70 mm in diameter and less than 40 mm in height. The WM7040-24V micro-blower meets various requirements.

In the component (6), the micro-hose network has two layouts in the garment: Y-shaped and 0-shaped, as shown in FIG. 9.

FIG. 10 shows the hot-side heat sink and the cold-side heat sink attached to the two sides of the thermoelectric module; and FIG. 11 shows a thermoelectric conversion unit (LECU). The cold side of the thermoelectric module is at a lower part, and the heat exchange chamber at the lower part temporarily stores cold energy. The external air inlet and outlet are not in the same straight-through line, but staggered from left to right, such that the air flow can fully take away the cold energy generated by the thermoelectric module. The hot side of the thermoelectric module is at an upper part, and the four sides of the main frame package are provided with vents. The heat dissipation fan is provided above the hot-side heat sink to help the hot side fully dissipate heat. Based on the features of the selected components and the external packaging module, the personal thermal comfort device is light in weight, small in size, energy-efficient and portable. A control module is added to control the temperature output of the personal thermal comfort device. FIG. 12 shows the personal thermal comfort device formed by the TECU with the micro-blower and the special garment with the micro-hose network.

The design process of the present disclosure is as follows. 1) An appropriate thermoelectric modules that can fully supply heat is selected, and it has the following parameters: DC power supply; working environment temperature -50°C to 80°C; cooling power 50-120 W; maximum temperature difference 40°C to 80°C; and external size 40 mm * 40 mm * X mm. 2) An appropriate heat dissipation fan is selected, and it has the following parameters: DC power supply; working voltage 12 V or 24 V; power 4-12W; speed 5,000-12,000 rpm; air volume 5-16 cfm; external size 40 mm * 40 mm * X mm. 3) The hot side and cold side are provided with heat sinks of different materials and different topologies. The topology is optimized to optimize the heat dissipation capacity. A straight-through-finned copper heat sink is provided on the hot side, and a four-row-finned aluminum heat sink is provided on the cold side. The hot-side heat sink and the cold-side heat sink are attached to the two sides of the thermoelectric module to enhance the heat and cold conduction effect. 4) The external packaging module is designed. The thermoelectric module, the heat sinks and the heat dissipation fan are packaged by means of 3D printing to meet the detachable and portable requirements. 5) The micro-blower is a brushless DC blower, which provides the external air flow to blow the cold energy generated by the TECU to the human body through the micro-hose network, to improve the thermal comfort of the human body. The micro-blower has the following parameters: input voltage 24-36 V; power 50-100 W; no-load speed 30,000-50,000 rpm; maximum air volume 200-300 L/min; and air pressure 5-10 KPa, 6) The Y-shaped or 0-shaped micro-hose network is embedded in the garment to enhance the cooling effect of the human body.

The thermal management method of the personal thermal comfort device based on the Peltier effect includes the following steps. I) The thermoelectric module is integrated with the heat sinks and the heat dissipation fan to form the TECU, and the TECU is packaged by the external packaging module. 2) Air is guided by a micro-air pump through a pipe to pass through the TECU for heat exchange, and the air after heat exchange is sent into the micro-hose network embedded in a wearable garment through a pipe. 3) An expected temperature of the TECU outlet is sent to the single-neuron proportional integral differential (PID) controller, and a control output of the single-neuron PID controller is obtained. 4) Control strategy is performed by a microcontroller, and input voltage of the thermoelectric module is adjusted by means of pulse width modulation (PWM) according to control output given by the single-neuron PID controller.

As shown in FIG. 13, the PID controller features a simple structure and principle, easy engineering implementation, and high robustness, and is widely used in practical applications.

The neural network is introduced into the PID controller to improve the coefficients in real time, to deal with the impact of environmental noise, load disturbance, etc. and improve the control effect. In the control process of the temperature control system, the supervised Hebbian learning rule is introduced to update the weight coefficient of the temperature control system. The PID controller can be regarded as a self-tuning PID controller, which realizes the self-adaptive and self-organizing functions against uncertainties of system structure or parameter.

In order to track the temperature setpoint of the 'ECU outlet, the single-neuron PID algorithm is applied to the temperature control system to enhance the stability and rapidity of the temperature control system. The neural network has the advantages of desired fault tolerance and strong anti-interference ability. Integrating the neural network with the classical PID control algorithm, fast and accurate temperature tracking is realized by regulating the input voltage of the thermoelectric module.

In step 3), the single-neuron PID controller is built with a single-neuron PID algorithm, and a single-neuron PID control formula is Azt(k)=K(co,x,+to,x,+coix") where, Au(k) denotes the increment of control output, K denotes the neuron gain coefficient; xi=e(k)-e(k-1), x2=e(k), x3=e(k)-2e(k-1)+e(k-2) are three neuron input signals, e(k)=r(k)-n(k) denotes the temperature deviation signal at the kth sampling period; r(k) and n(k) denote the expected temperature and actual temperature of the TECU outlet respectively; co, 0=1,2,3) denotes the weight factor of a corresponding input.y,, the weighting factors are adjusted online by the following supervised Hebbian learning rule: co1(k+1)=co,(k)+7771e(k)u(k)(e(k)+ Ae(k)) co,(k +1)=co,(k)+ne(k)u(k)(e(k)+ Ae(k)) coi(k +1) = co,(k)+n,,e(k)u(k)(e(k)+ Ae(k)) where, qp, q,, and rid denote learning rates of proportional, integral and differential components respectively; Ae(k)=e(k)-e(k-I); and ti(k)=u(k-I)+Au(k) denotes control output of the single-neuron MD controller.

In step 4), according to the above control output u(k), input voltage of the thermoelectric module is regulated by means of PWM. An Arduino development board is used as the microcontroller. This is a single-chipmicrocontroller with open source code. It uses an Atmel AVR microcontroller, and an open source software and hardware platform, is built on a simple input/output (I/O) interface panel, and uses a processing/wiring development environment similar to Java and C language.

Because Arduino can only adjust the voltage in the range of 0-5 V the external power and PWM module are introduced. The external power provides power for the PWM module. According to control output of the microcontroller, the PWM module generates corresponding input voltage for the thermoelectric module.

As shown in FIG. 14, the thermoelectric module is controlled to generate different power through PWM output of different voltage values. PWM is the main way to output analog quantity in digital circuit. In Arduino, there are two methods to generate PWM waves. The first method is to directly output the PWM wave through a pin with -and use a command of anatogWrite (pin, val). The val is an integer value within 0-255, corresponding to the voltage of 0 V to +5 V The second method is a manual method, which realizes PWM through a code. This method has obvious advantages, that is, the PWM proportion can be more accurate, the cycle and frequency can be controlled, and all pins can output the PWM wave. Therefore, the second method is adopted in the present disclosure to output the PWM wave.

Feedback control is conducted on the input voltage of the thermoelectric module, to adjust the temperature difference between the cold side and the hot side, and then maintain the TECU outlet temperature at the specified setpoint, as shown in FIG. 14. The local ambient temperature around the participant wearing the garment is measured in real time, and then current comfort is evaluated to obtain the temperature setpoint for the TECU outlet. The cooling effect is controlled by adjusting the input voltage for the thermoelectric module.

In the present disclosure, the specific thermoelectric module, heat dissipation fan and heat sinks are integrated into the detachable and portable TECU. The micro-blower feeds cold energy into the special garment. The whole device has the advantages of portability, excellent energy efficiency and temperature controllability. It can be integrated with the HVAC system of the building to establish a local thermal environment and improve personal thermal comfort. The temperature setting range of the central air conditioner can be broadened by the smaller device, thereby reducing the overall energy consumption of the building, and creating a huge application potential.

In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "an illustrative embodiment", "an example", "a specific example", or "some examples" means that specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above-mentioned terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present disclosure have been illustrated, it should be understood that those of ordinary skill in the art may still make various changes, modifications, replacements and variations to the above embodiments without departing from the principle and spirit of the present disclosure, and the scope of the present disclosure is limited by the claims and legal equivalents thereof

Claims (10)

1. CLAIMSWhat is claimed is: I. A personal thermal comfort device based on a Peltier effect, characterized by comprising a thermoelectric module, a heat dissipation fan, an external packaging module, a micro-blower, and a micro-hose network, wherein a hot side and a cold side of the thermoelectric module are respectively attached with heat sinks; the thermoelectric module and the heat dissipation fan are integrated into a thermoelectric conversion unit (TECLT) by the external packaging module with a channel; the TECU has one end connected to the micro-blower and an other end connected to the micro-hose network; and the micro-blower provides a hot or cold air flow to a garment with the micro-hose network, to provide a heat or cold source for a whole human body.
2. 2. The personal thermal comfort device based on the Peltier effect according to claim 1, characterized in that the thermoelectric module has a three-layer structure, comprising an intermediate layer composed of a bismuth telluride thermocouple and a deflector connected in series, and alumina ceramic layers on two sides of the intermediate layer.
3. 3. The personal thermal comfort device based on the Peltier effect according to claim 1, characterized in that the heat dissipation fan is mated with the thermoelectric module in terms of size, and is provided with multiple blades.
4. 4. The personal thermal comfort device based on the Peltier effect according to claim 1, characterized in that the heat sinks comprise a hot-side heat sink and a cold-side heat sink; the hot-side heat sink is made of red copper, and is provided with straight-through fins; and the cold-side heat sink is made of aluminum or copper, and is provided with one row, four rows or more than four rows of dense straight-through fins with an optimal thickness of 0.5-1.5 mm and an optimal spacing of 0.5-1.5 mm.
5. 5. The personal thermal comfort device based on the Peltier effect according to claim 4, characterized in that, the hot-side heat sink has an overall size of 40 mm * 40 mm * 11 mm, a base thickness of 3 mm, and is provided with 25 fins, each with a thickness of 0.5 mm; and the cold-side heat sink is provided with four rows of 0.8 mm thick fins arranged with a spacing of 0.6 mm.
6. 6. The personal thermal comfort device based on the Peltier effect according to claim 1, characterized in that the external packaging module comprises a main frame package, and an external air inlet part and a back cover carrying an air outlet part respectively communicated with two sides of the main frame package; the external air inlet part comprises a round-hole cylindrical air inlet (4), a rectangular connector (5) between the main frame package and the round-hole cylindrical air inlet, a smooth surface (6), reserved holes (7), and an internal air inlet (8); the round-hole cylindrical air inlet (4) is connected to the connector (5) between the main frame package and the round-hole cylindrical air inlet through the smooth surface (6); the reserved holes (7) are provided at two ends of a junction between two adjacent sides of the connector (5) between the main frame package and the round-hole cylindrical air inlet to serve as wire positions for the thermoelectric module; and the internal air inlet (8) is provided at a bottom of a side of the connector (5) between the main frame package and the round-hole cylindrical air inlet; the main frame package is a shell structure; a top end of the main frame package is provided with a round fan exhaust outlet (12); left and right sides of the main frame package are symmetrically provided with second hot-side heat sink vents (16); a back side of the main frame package is sequentially provided with a fan wire hole (13), a first hot-side heat sink vent (15), two thermoelectric module wire holes (14) arranged horizontally and symmetrically, and a counterpart (17) of the internal air inlet (8) from top to bottom; a front side of the main frame package is an open end side defined as a front shell (10); an internal space of the main frame package is divided into an upper space and a lower space by a partition (11) between the hot-side heat sink and the heat dissipation fan; the upper space is provided with a main heat dissipation chamber of the hot-side heat sink, and the fan exhaust outlet; and the lower space is provided with a main heat exchange chamber of the cold-side heat sink; and the back cover carrying the air outlet part comprises a back cover, a smooth connection surface (20), and a round-hole cylindrical air outlet (21); the back cover has a double-layer structure with a lateral section forming an L-shaped shell; one side of a vertical part of the L-shaped shell is clamped into the front shell (10); and an other side of the vertical part of the L-shaped shell forms a protruding rectangular end, connected to the round-hole cylindrical air outlet (21) through the smooth connection surface (20), at a bottom; and the other side of the vertical part of the L-shaped shell is provided with a counterpart (22) of the first hot-side heat sink vent (15).
7. 7. The personal thermal comfort device based on the Peltier effect according to claim 1, characterized in that the micro-hose network has a Y-shaped topology or an 0-shaped topology.
8. 8. A thermal management method of the personal thermal comfort device based on the Peltier effect according to claim 1, characterized by comprising the following steps: 1) integrating the thermoelectric module with the heat sinks and the heat dissipation fan to form the TECU, and packaging the 1ECU by the external packaging module; 2) guiding, by a micro-air pump, air through a pipe to pass through the TECU for heat exchange, and sending the air after the heat exchange into the micro-hose network embedded in a wearable garment through a pipe; 3) sending a target voltage to a single-neuron proportional integral differential (PLD) controller, acquiring a control parameter output by the single-neuron PID controller, and deriving a control voltage of the thermoelectric module according to the control parameter, and 4) controlling by a microcontroller, and adjusting a power of the thermoelectric module by means of a pulse width modulation (PWM) wave according to data given by the single-neuron PID controller.
9. 9. The thermal management method of the personal thermal comfort device based on the Peltier effect according to claim 8, characterized in that in step 3), the single-neuron PID controller is built with a single-neuron PID algorithm, and a single-neuron PID control formula is Au(k)= K(o1x1+ay2x2+o,x") wherein, Au(k) denotes an increment of a control output, K denotes a neuron gain coefficient; xi-e(k)-e(k-1), x2=e(k), x3-e(k)-2e(k-1)1 e(k-2) are three neuron input signals; e(k)=r(k)-n(k) denotes a temperature deviation signal at a kth sampling period; r(k) and n(k) denote an expected temperature and an actual temperature of a TECU outlet respectively; co, (i=1,2,3) denotes a weight factor of the corresponding input xi, the weighting factor is adjusted online by the following supervised Hebbi an learning rule: w1 (k +1)= ol(k)+ pe(k)u(k)(e(k)+ Ae(k)) 02(k +1) = 692.(k)+ ne(k)u(k)(e(k)+ Ae(k)) 693(k +1) = o,(k)+ qie(k)u(k)(e(k)+ Ae(k)) where, np, rb, and rid denote learning rates of proportional, integral and differential components respectively; Ae(k)=e(k)-e(k-1); and u(k)=u(k-1)+ Au(k) denotes the control output of the single-neuron PID controller.
10. 10. The thermal management method of the personal thermal comfort device based on the Peltier effect according to claim 8, characterized in that in step 4), according to the control output u(k), a corresponding input voltage value is obtained by means of PWM to control the thermoelectric module to generate different power, in this design, a PWM wave of the microcontroller only adjusts a voltage of 0-5 V; an external power and a PWM module are introduced; the external power provides power for the PWM module; and according to the control output of the microcontroller, the PWM module generates a corresponding input voltage for the thermoelectric module.