KR101126392B1 - Autonomous garment with active thermal control and powered by solar cells - Google Patents

Abstract

The invention refers to an autonomous system and to a method that allows the active thermal control of garments using solar cells as the power source. In the simplest configuration, the system includes a piece of clothing with solar cells ( 1 ), a thermal module able to generate heat and cold ( 3, 4 , and 5 ), and a unit for controlling and monitoring the internal environment ( 6 ). In order to increase versatility and to optimize operation conditions, the system includes batteries ( 2 ) that can be charged by the solar cells or externally, increasing energy autonomy and improving performance in low radiation conditions. Proper distribution of electric resistors ( 3 ) and refrigeration pipes ( 7 ) allow a fine-tuning regulation of temperature inside the garment. The garment is developed not only for standard conditions but also for extreme heast and cold environments, being optimised wither for standard solar radiation or other relevant spectral source.

Description

AUTONOMOUS GARMENT WITH ACTIVE THERMAL CONTROL AND POWERED BY SOLAR CELLS}

The present invention relates to an independent garment having a solar cell for the power source and capable of active thermal control.

The present invention corresponds to the spotlight in the field of clothing known as intelligent wear (i-wear). This relates to automatic temperature control systems and methods for garments that take into account extreme conditions as well as standard conditions. The invention also refers to a special element for powering a safety vest with an accessory.

Many patents are associated with the present invention. The documents relating to heating techniques for garments are as follows: WO03059099, EP1197722, US2001047992, DE19835984, US5893991, US5643480, EP0287294, US4705935, FR2577390, US2003006229 and US4404460 with thermoelectric effect. FR2752363 referring to solid fuels and liquid fuels. US6439942 and FR2577116 describing solar panels. US4539714 using a microdendritic solar collector. Other documents are about the cooling process of clothing: DE19755181 and DE19749436 describe flexible stripes; GB2352385, US6125645, US5289695 and US5111668 include suitable materials; WO02067707, US6257011, FR2719892 and US5217408 refer to forced draft by a fan; US5438707 uses fan and compressed air. US6134714, US2002073481, US2002069448, FR2756709, US5415222, US5263336 and US3736764 use liquid cooling. US5755110 and DE20011331 refer to heat exchange equipment; US5386823 describes a ventilated thermal protective suit. In addition, document DE19745889 contains matrix resistors and Peltier cells for heating and cooling effects, while US5603648 describes safety vests with accessories.

The present invention is directed to independent garments capable of active thermal control and operated with solar cells and designed for extreme weather conditions as well as standard conditions. Hereinafter, "autonomous" means that there is no need to plug in the wires while ensuring energy independence and portability of the garment. "Active thermal control" also generates heat and cold in clothing, and refers to the ability to dynamically control the internal temperature according to the external environment and the needs of the wearer.

Currently, there are several ways to provide temperature control of garments, which can be divided into two different categories: heating and cooling. However, few patents cover both kinds at the same time.

a) heating garment

In general, a heating system embedded in a garment uses a thermoelectric effect to supply heat to clothes. The current provided through the battery or wire is converted into heat in resistive elements embedded in clothing and blankets, such as jackets. Such techniques are described in patents WO03059099, EP1197722, US2001047992, DE19835984, US5893991, US5643480, EP0287294, US4705935, FR2577390, US2003006229, US4404460. Most of these include means for maintaining the heat generated through the use of special fibers or structures. Patent FR2752363 refers to a heating system that operates on solid fuels and liquid fuels supplied to an engine to generate heat. Patents US6439942 and FR2577116 describe a garment in which heat is generated through a resistive element operated by a solar panel. Patent US4539714 and references in that patent relate to the use of microdendritic solar collectors that generate heat directly to clothes.

b) cooling garment

The cooling garments already presented relate to other technologies such as suitable shapes, fibers and special materials, natural or forced ventilation, coolant or evaporation to generate cold air. Patents DE19755181 and DE19749436 disclose configurations with flexible stripes that allow natural ventilation. Sweat removal and evaporation by cooling and cooling on suitable materials are disclosed in patents GB2352385, US6125645, US5289695 and US5111668. Meanwhile, forced ventilation systems using small fans driven by batteries or directly connected to the wires are described in patent WO02067707, US6257011, FR2719892 and US5217408. Patent US5438707 simultaneously uses compressed air and cooling with a fan. Patents US6134714, US2002073481, US2002069448, FR2756709, US5415222, US5263336 and US3736764 describe a system in which a freezing liquid is present inside a pipe embedded in a garment to allow cooling by evaporation. Patent US5755110 describes a system using a special material for heat absorption, and patent DE20011331 discloses the use of special properties of fiber material to store and release excess heat as needed. Finally, patent US5386823 relates to a ventilated garment having a mask connected to a low portability cooling device.

c) clothing with both heating and cooling systems;

There are many patents and documents on heating and cooling systems and methods, but only one is aware of using both techniques in one garment. Patent DE19745889 discloses a garment having a matrix resistance element for heating and a Peltier element for cooling, connected to a power source, that is, a power line, a friction wheel, a generator or battery driven with a propeller.

d) other applications

Most documents mention heat or cold generation, but some clothing includes accessories for other applications. Patent US5603648 describes a safety vest with several accessories, an LED driven by fiber optic and solar cells, a resistor powered by a battery to supply heat, and other signaling and survival instruments. This is particularly useful for rescue operations and other dangerous missions.

e) power independence

Most independent systems available on the market generate heat or cold but do not have a solution for both heat and cold mounted in the same garment. Although some small items of clothing contain batteries for some energy independence, most of the system must still be connected to the power line. Thus, a system connected to a power line is neither portable nor independent, and lacks independence when using batteries. Thus, independent clothing requires a large, heavy battery, or prevents the installation of additional thermal control devices, such as cooling methods with low thermal cycle efficiency, and must use very low power.

Some small garments use solar cells or energy collectors to power the resistive elements used to heat the garment.

f) automatic temperature control

There are many ways to control the temperature inside the garment, but most of them use manual methods. Although some methods include mechanisms to control the flow of heat and cold, such as the orientation of the flexible stripe, the most common method continues to emit heat and cold like a fan. Nevertheless, a more effective method is to use thermostats that control the temperature by turning the thermostat on and off to control the flow of heat and cold. These controls are simply used to turn the source for heat generation on and off, thus eliminating the need for sophisticated algorithms. However, the development of a system with active thermal control enables more efficient management of heat and cold inside the garment.

g) conclusion

Today, there are a number of methods and solutions for generating heat and cold in clothing, as can be seen in a number of patents and other published documents. However, these methods also have some limitations in common.

The biggest limitation of thermally controlled clothing is power generation, because the system is capable of generating significant amounts of power, but is not portable, or generates very little power even when the power supply is independent.

Most of the available systems have heating or cooling devices, but these two methods cannot be provided in a single garment, mainly due to power constraints.

Inserting both of the heating and cooling devices into the garment requires more efficient management of thermal control.

 All systems and methods claimed so far do not have features such as power independence, automatic temperature control, cooling and heating cycles, and portability.

All the systems ever claimed fail to satisfy features such as power supply independence, thermostats, cooling and heating cycles, and portability at once. Currently available cooling garments do not use solar cells to power the system. The two available systems that include solar cells for heating insist on using only solar radiation. Currently all methods of providing temperature control use either a heating device or a cooling device, but do not include all solutions in a set of clothing.

The present invention reduces the limits of portability and power independence and allows for heat cycles of heating and cooling in the same garment. One of the main objectives of the present invention is to solve this limitation without significantly increasing the weight. The present invention also proposes a more effective method for temperature distribution and power management.

Basically used devices in garments include solar cells, batteries, cooling devices, heating devices, active thermal controllers, wiring grids and auxiliary devices.

The solar cell is assembled in a flexible substrate and may include special filters or optical components. The solar cell uses a flexible substrate made of inexpensive silicon beads sandwiched between two thin layers of two metal foils embedded in a plastic cover. The metal plate adds physical strength and serves as an electrical contact. In addition, the wavelength for the maximum conversion of light energy into electrical energy can be shifted to match other radiation sources. Thus, in addition to solar radiation, other energy sources such as fluorescent lights or flames can also be used.

The use of batteries in clothing is convenient not only for storing energy, but also for power stabilization, i.e. when power transients occur in solar cells. The new technology enables the development of flexible ultra-thin batteries, and the series or parallel connection increases power storage to over 200 Wh / kg. In addition, the thin film battery can be easily shaped, allowing weight distribution within the garment and the flexibility of the substrate allows for ergonomic design.

The apparatus used to generate cold air uses several techniques. The Peltier cell is made of two dissimilar metals, and applying a DC voltage to a closed circuit produces a temperature change at the junction of the two metals. Peltier cells are light, free of moving parts and can be used in any orientation. Moreover, it can be stacked to obtain a significant temperature difference. Miniaturized compression coolers with a coefficient of performance (COP) of ˜4 are also available. Therefore, the vapor compression cycle is a very effective system for providing a cooling process to the garment. In addition, the use of flexible thin pipes enables proper distribution of heat flow in the garment.

The most effective way of supplying heat to clothing is to convert electrical energy into heat through resistive elements. The wiring, high flexibility and light weight of electrical resistive elements is an advantage as a more suitable device for generating heat inside garments.

 Proper thermal control in clothing is much more efficient using active devices. This is because on / off systems are not effective in complex systems that use both heating and cooling cycles simultaneously. On the other hand, the active thermal control presented herein uses variables calculated from human activities, external environment and preset conditions as well as the cycles mentioned above. Thus, the thermal control device can use sophisticated algorithms.

Wiring is an important issue in the assembly process. Although the flexibility of solar cells, batteries, resistors, and pipes is large, it is fundamental to study the stresses and fatigue that occur at some of the garment's junctions, which are related to the joints of the body.

Because of the apparel's useful power, an auxiliary plug can be provided to power external devices such as laptops, cell phones, audio equipment, and other low-voltage appliances.

1 shows a set of garments with some devices for powering, heating, cooling and controlling the entire system.

2 shows, as an example, a uniform in which a solar cell is shown on its surface.

In a simple configuration, the system comprises one or several garments, a solar cell 1, a battery 2, a resistor element circuit 3, a cooling device 4, an automatic thermal controller 6. The Peltier cell 5 is used with or in place of a resistive element and a cooling device that can be used for heating and cooling. By simply changing the direction of the current flowing in the cell, the Peltier cell can supply or remove heat from the same device, thus increasing the versatility of the garment. Solar cells convert electromagnetic radiation into electrical power to power electrical devices. The distribution of the resistance element and the cooling pipe 7 is adjusted according to the needs of the human body in order to supply or remove heat from the garment. The thermal device ensures that the temperature inside the garment is maintained within a selected range, which may be a metabolic function, climatic conditions, breathable fabric material, and preset values by the wearer. In addition, specific algorithms outline the thermal control device and manage heating and cooling operations inside the garment. Batteries serve two different purposes in the system. First, when there is a large change in power generation, it is used to stabilize power consumption. Second, when radiation levels are low or no longer useful, batteries are used to provide extra power and store energy to increase energy independence.

a) solar cell

Solar cells absorb radiant energy, convert it into electricity, and supply it to the equipment being controlled. The generated power may also be stored in the battery. The solar cell is the outer active layer of the garment, must be flexible and have low stress due to prolonged bending. In addition, solar cells should have good wiring characteristics.

Solar cells must be covered with a visible outer layer to prevent weather damage. This layer should be thin, flexible and transparent to visible radiation.

The overall power efficiency of the solar cell should be at least 10% to provide sufficient energy to the thermal device. The figure is the efficiency at the technical level at this point for a flexible solar cell.

Solar cells cover as much of the outer layer of clothing as possible to maximize the useful area. However, special human joints such as shoulders, elbows and knees can damage the solar cells, so do not install solar cells in the joints where the strength of the bend in the garment is strong. Specialty wiring is used to connect the solar cells in the entire grid and electric bus connectors that distribute power and control signals to all devices.

b) battery

Batteries store energy supplied by solar cells or wires. The main function of the battery is to store energy and stabilize the power.

Batteries should be thin, light, flexible, rechargeable, and less stressed over long periods of bending. The flexible battery at this point allows up to 200 Wh / kg, which allows for three hours of independence for minimal heating and cooling. The battery layer is embedded in the garment and has the same restrictions on bending as solar cells. The battery is connected to an electrical bus connector that distributes power to all devices and controls the signals.

c) heating cycle

Clothing has two different systems for supplying heat. The most efficient way to warm clothes is to use a resistive element, and another way is to use Peltier cells.

The resistive element should be thin, flexible and light. In addition, the stress on bending for a long time should be small and have a good wiring connector. The resistive element distribution and wiring grid inside the garment are selected to provide adequate heat flow inside the garment. In addition, some of the resistive elements can supply heat independently, allowing for a balanced distribution of energy if necessary. For example, this technique can vary energy distribution to the chest, arms, and legs. The resistive element layer is embedded in the garment and may be included directly in the fabric.

Peltier cells are used for both heating and cooling and are also embedded in clothing. These properties make Peltier cells useful for areas of clothing susceptible to high thermal inertia. On the other hand, since the Peltier cells are heavier than the resistive elements, they are appropriately distributed to equalize the weight in the garment.

The resistive element and the Peltier cell are connected to the electrical bus connector which distributes power to all devices and controls the signal.

d) cooling cycle

The use of miniaturized cooling cycles with high coefficient of performance (COP) is a suitable method for providing a cooling system in a garment. The use of flexible thin pipes is effective for the proper distribution of temperature inside the garment. The use of tubes of different diameters and pipe distribution distributes cold air unevenly by using different flows of fluid and valves in the pipe.

The cooling cycle system is connected to the electrical bus connector which distributes power to all devices and controls the signals.

e) thermostat

Simple thermostats used so far for temperature control of garments are useful, but they are not efficient because simple on / off control is not suitable for more advanced systems. Therefore, use a programmable microcontroller. Temperature management includes some important input values, such as sensor signals, user-set settings, feedback conditions, and device performance monitoring figures.

Using temperature sensors (ie, thermometers) to monitor clothing temperature, external environmental conditions, and the wearer's body temperature provides useful information.

 Models representing heat flow generation and distribution in the human body are included. Heat flow levels are a function of physiological parameters such as human activity and climatic conditions.

Special algorithms have been developed to process all information related to sensors, device status, human activity models, climate parameters and preset conditions. The algorithm is performed in a microcontroller device that investigates and analyzes the temperature in the garment, regulates the production of heat and cold, and preserves thermal preset comfort conditions. The microcontroller is connected to the electrical bus connector that provides signal and power distribution to control the garment, while managing all devices and accessories.

f) other applications

The power generated from clothing can be used for other purposes, in particular for energying small applications such as laptops, audio equipment, positioning systems, cell phones, digital cameras and signaling and warning devices. Small applications are connected to the electrical bus connector providing power distribution to all devices.

g) conclusion

The present invention is unique in the following features.

1. The garment has both heating and cooling cycles, with automatic thermal control.

2. Solar cells are used to power heating and cooling devices.

3. The garment may use other spectral energy support such as flame visible radiation in addition to solar heat.

The invention, which simultaneously provides active heating and cooling temperature control, can be applied to a variety of climatic conditions and can be included in other clothing types, ie jackets and uniforms (FIGS. 1 and 2). The system can operate without solar radiation in the presence of other sources of radiant energy, such as artificial lighting (eg lamps). Particularly useful situations are provided by flame radiation, which can be converted to electricity and used to cool firefighter uniforms.

Various garments may include sensors to monitor external weather conditions, communication and positioning devices, and luminescent and acoustic signaling devices. Sensors of this kind and simple devices are particularly important in residential areas with extreme conditions and sparsely populated densities such as deserts, polar regions and mountainous regions.

Further applications of the present invention relate to the use of solar cells to energize small portable electrical devices such as laptops, cell phones and audio players.

Claims (11)

As an independent garment with a solar cell for the power source and active thermal control, A solar cell 1 that absorbs radiant energy and converts it into electrical energy; A battery 2 connected to the solar cell via an electrical bus connector to store electrical energy supplied by the solar cell; A resistance element (3) connected to the solar cell and the battery via an electric bus connector and receiving power from the solar cell or the battery to convert electrical energy into heat to supply heat to the garment; A cooling device (4) connected to the solar cell and the battery via an electric bus connector to receive electric power from the solar cell or the battery and to supply cold air to the garment using a vapor compression cycle; Peltier cells (5) connected to the solar cell and the battery via an electric bus connector to supply power and heat to the garment by receiving power from the solar cell or the battery; And An independent garment comprising a solar controller, a battery, a resistor, a cooling device, and a microcontroller (6) connected to the Peltier cell via an electrical bus connector to regulate the generation of heat and cold. The method of claim 1, And the solar cell is on the outer layer of the garment. The method of claim 1, And the battery is embedded in the garment. The method of claim 1, And wherein said resistive element is embedded within said garment and distributed within said garment for heat transfer. The method of claim 1, And said Peltier cell is embedded within said garment and distributed within said garment to produce heat and cold. The method of claim 1, And said cooling device comprises pipes distributed in said garment for delivery of cold air. The method of claim 1, And at least one mechanism of power plugs, positioning systems, lighting and acoustic signal applications, thermal sensors connected to the electrical bus connector. The method of claim 1, And the microcontroller is connected to a solar cell, a battery, a resistive element, a cooling device, and a Peltier cell via the electrical bus connector for active thermal control of the garment. delete The method of claim 1, The garment is a firefighter uniform, And said solar cell converts flame radiation into electric power. delete

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