KR101609239B1 - Device for Heating the Battery Pack Using Phase Change Material and Temperature Control Apparatus for the Battery Pack Comprising the Same - Google Patents

Abstract

The present invention relates to a phase change material (PCM: Phase Change Material) which absorbs or emits heat during a phase transition, in which a phase change occurs due to temperature conversion or stimulation, an activator for applying an electrical or physical stimulus to cause a phase transformation of the phase change material from the B phase to the A phase, A first storage member that encloses the heating member and the active member in a sealed state, and a second storage member that contains the first storage member in a state in which fluid can flow through the inlet and the outlet The battery pack heater according to claim 1,

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery pack heater using a phase change material,

The present invention relates to a phase change material (PCM: Phase Change Material) which absorbs or emits heat during a phase transition, in which a phase change occurs due to temperature conversion or stimulation, an activator for applying an electrical or physical stimulus to cause a phase transformation of the phase change material from the B phase to the A phase, A first storage member enclosing the heating member and the active member in a sealed state, and a second storage member containing the first storage member in a state in which the fluid can flow through the inlet and the outlet; To a battery pack heater.

The increase in the price of energy sources due to the depletion of fossil fuels, the increase of interest in environmental pollution, and the demand for environmentally friendly alternative energy sources are becoming indispensable factors for future life. Various researches on power generation technologies such as nuclear power, solar power, wind power, and tidal power have been continuing, and electric power storage devices for more efficient use of such generated energy have also been attracting much attention.

Particularly, in the case of a rechargeable secondary battery, the demand as an energy source is rapidly increasing as technology development and demand for mobile devices are increasing. In recent years, as a power source for electric vehicles (EVs) and hybrid electric vehicles And the use area has also been expanded for use as a power auxiliary power source through a grid.

In order to use such a secondary battery as a power source for an electric vehicle (EV), a hybrid electric vehicle (HEV) and the like, a large output capacity is required. To this end, a plurality of small secondary batteries (unit cells) And a plurality of such battery modules are connected in parallel or in series to form one battery pack.

However, such a high-output large-capacity secondary battery generates a large amount of heat during the charging and discharging process. If the heat of the unit cell generated during the charging and discharging process can not be effectively removed, heat accumulation occurs, resulting in deterioration of the unit battery. Therefore, a cooling apparatus for a battery pack for a vehicle, which is a high-capacity large-capacity battery, has been required, and studies have been actively conducted, and various cooling apparatuses have been developed and commercialized.

Fig. 1 schematically shows a cooling apparatus of a conventional battery pack for a vehicle.

1, the cooling apparatus 100 of the vehicle battery pack includes a heat exchanger 102 for lowering the temperature of cooling water for cooling the battery pack 101, A piping 104 for transferring the high temperature cooling water 105 discharged from the battery pack 101 to the heat exchanger 102 after the heat exchange with the battery pack 101, (106), and a pump (107) for the overall transfer of the cooling water.

Therefore, the cooling water heated after passing through the battery pack is cooled again through the heat exchanger and transferred to the battery pack, whereby deterioration of the battery pack can be prevented, and the safety can be improved accordingly.

However, in order for the battery pack including the secondary battery to be used as a power source for a device or a system that is driven in various mixed environments such as an electric vehicle (EV) and a hybrid electric vehicle (HEV) There is a demand for a complex temperature control system for coping with the above various environments.

Particularly, when the temperature is lowered, the temperature of the vehicle in which most parts are made of metal is rapidly lowered, and the battery pack temperature of the vehicle left in the low temperature environment for a long time is also lowered. ≪ / RTI >

In addition, since the vehicle can not start normally due to a low temperature, or may cause a malfunction of the battery, a complex temperature control system capable of solving the problem in a low temperature environment is required in addition to the conventional battery pack cooling system.

Therefore, there is a high need for a technology capable of fundamentally solving these needs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art and the technical problems required from the past, and the inventors of the present application have conducted intensive research and various experiments, And an object thereof is to provide a battery pack heater capable of improving operating performance.

Still another object of the present invention is to provide a battery pack temperature control system in which the battery pack heater is added to a conventional battery pack cooling apparatus.

In order to accomplish the above object, a battery pack heater according to the present invention includes: a phase change material (PCM: Phase Change Material) that absorbs or emits heat when a phase change occurs due to temperature change or stimulation;

A heater heated upon application of electricity to induce a phase transformation from phase A to phase B of the phase change material;

An activator that applies an electrical or physical stimulus to cause phase transformation of the phase change material from the B phase to the A phase;

A first storage member in which the phase change material, the heating member, and the active member are embedded in a sealed state;

A second reservoir in which the first storage member is embedded with the fluid flowing through the inlet and outlet;

As shown in FIG.

As described above, the battery pack heater according to the present invention and the battery pack temperature control system including the same include a phase change material that absorbs or discharges heat at the time of phase change, thereby heating the battery pack through phase- The operating performance of the battery pack can be improved in a low temperature condition.

Further, by adding the battery pack cooling system to the conventional battery pack cooling system without a separate design change, it is possible to reduce the design and manufacturing costs, simplify the structure, improve the safety of the battery pack under various mixed conditions such as high temperature and low temperature, So that it is possible to exert the operating performance.

In one specific example, the A phase is a solid phase and the B phase is a liquid phase.

That is, the phase-change material absorbs heat while being phase-converted from a solid phase to a liquid phase by heating, and emits heat while phase-converting from a liquid phase to a solid phase by electrical or physical stimulation.

In another specific example, the lowest melting point of the phase change material may be 40 degrees Celsius. The melting point refers to the temperature at which the solid phase and the liquid phase are in equilibrium and coexist under a constant pressure, that is, the temperature at which the phase change material causes phase transformation. The phase change material of the battery pack heater according to the present invention, Phase transition from the solid phase to the liquid phase while absorbing the surrounding heat and accumulating as latent heat.

When the melting point of the phase-change material is too low, the phase transition of the solid state phase-change material to the unstable supersaturated phase state can be performed without heating the heating member due to deterioration of the device including the battery pack or increase in temperature Can cause.

In this case, the phase-change material of the liquid phase may cause heat to be released from the liquid phase to the solid phase due to a slight impact externally applied or a small static electricity, and accordingly, the deterioration and temperature The performance may be deteriorated due to the rise, and the safety of the equipment including the same may be deteriorated.

Therefore, the lowest melting point of the phase-change material of the battery pack heater according to the present invention should not be in a too low temperature range, and may preferably be more than 40 degrees Celsius.

In addition, the latent heat per unit mass of the phase change material may be 150 to 500 kJ / kg.

When the latent heat per unit mass of the phase change material is less than 150 kJ / kg, the battery pack can not emit heat to heat the battery pack to a desired temperature, and when it exceeds 500 kJ / kg, The temperature of the battery pack and the connecting pipe may be rapidly increased, and the durability of the battery pack may deteriorate.

The phase change material included in the battery pack heater according to the present invention is not particularly limited as long as it has the above-described characteristics and can exhibit a desired effect. Preferably, paraffin, polyethylene glycol, Of Na ₂ S ₂ O ₃ .5H ₂ O, CH ₃ CO ₂ Na 3H ₂ O and MgCl ₂ .6H ₂ O.

In addition, the phase-change material may be appropriately selected depending on various factors such as the mass and specific heat of the battery pack to be heated.

The battery pack heater according to the present invention includes a heating member capable of heating the phase change material, and the heating member may be a heating coil.

The heating coil is not particularly limited as long as it can cause phase transformation from a solid phase to a liquid phase by heating the phase-transforming material. Preferably, the heating coil is made of nichrome (Ni-Cr) or iron chromium (Fe-Cr) Iron-chromium aluminum (Fe-Cr-Al).

Further, the battery pack heater according to the present invention includes an active member for converting a liquid phase-change material into a solid phase.

The active member may be electrically connected to an external control device and may be configured to apply electrical or physical stimulation to the phase change material by an electrical signal of the external control device.

In this case, the external control device may be a battery management system (BMS).

Therefore, in the phase-change material of the battery pack heater according to the present invention, the active member applies an electrical or physical stimulus to the phase-change material by an electrical signal of the external control device in a low-temperature environment, So that the battery pack can be heated.

In addition, the solid phase-change material after completion of the heat release and phase conversion is solidified until it is heated by the heating coil, which is the next heating member, and is converted back to the liquid phase. And can be stored in the storage member.

The storage member includes a first reservoir containing the phase change material, the heating member and the active member in a sealed state, and a first storage member in a state in which the fluid can flow through the inlet and the outlet And a second storage member.

In one specific example, the first storage member may be made of an elastic material whose size can be changed according to a volume change of the phase change material during phase conversion.

Generally, as all materials undergo a phase change from solid to liquid, the physical arrangement of the molecules changes, and thus the volume changes as the density changes.

In particular, the phase-change material may be more voluminous in volume, as compared to a general material, due to frequent phase changes for operation of the equipment, and thus the first storage member incorporating the phase- The material can be made of an elastic material whose size can be changed according to the volume change during the phase conversion of the phase change material.

In another specific example, the first storage member or the second storage member may be cylindrical, elliptical, or polygonal in cross-section, and preferably the fluid flow and heat exchange efficiency through the storage member are considered , It can be made cylindrical.

In this case, since the first storage member and the second storage member are formed in the same shape, the fluid can flow smoothly and the effect of efficient heat exchange can be exerted.

Also, for this purpose, the first storage member may be located at the center of the second storage member.

The second storage member may further include a baffle for heat exchange of the fluid flowing therein.

The baffle is a kind of partition, in which a fluid flowing inside the storage member flows through the inner space between the first storage member and the second storage member to form a flow path through the partition so that efficient heat exchange can take place.

In this case, the baffle has a spiral structure surrounding the outer surface of the first storage member on the inner surface of the second storage member, so that the fluid uniformly flows through the inner space between the first storage member and the second storage member, Can be maximized.

In one specific example, the fluid may be an antifreeze, and more particularly, the fluid may be present in a fluid state even at low temperatures by including ethylene glycol, heated by the battery pack heater, The battery pack can be rapidly heated while circulating.

In another specific example, the battery pack heater according to the present invention may further comprise a first temperature sensor for measuring the temperature of the fluid.

In this case, the first temperature sensor may be configured to automatically operate the battery pack heater at a low temperature by measuring the pre-operation temperature of the battery pack heater and delivering an electrical signal to the external control device at or below the set temperature By measuring the temperature during operation and after operation of the battery pack heater, overheating due to malfunction of the battery pack heater can be prevented.

The present invention provides a battery pack temperature control apparatus further comprising a battery pack heater and a battery pack cooling apparatus, wherein the battery pack heater and the battery pack cooling apparatus are connected to the battery pack by at least one pipe, And may be a structure that flows through the pipe to heat or cool the battery pack.

In addition, the direction of flow of the fluid is regulated in the direction of the cooling device or the heater by a valve provided in the pipe, and in this case, the valve may be a three-way valve.

Specifically, the battery pack temperature controller may further include a battery pack heater for the conventional battery pack cooling apparatus. More specifically, the battery pack temperature controller may include a pipe connected to allow the fluid discharged from the battery pack to flow into the cooling device, A three-way valve is formed in the piping so that the fluid having passed through the cooling device flows into the battery pack. The three-way valve is connected to the piping so that the fluid discharged from the battery pack heater flows into the battery pack. And a pipe connected to connect the fluid that has passed through the battery pack to the battery pack heater.

In a general situation, the fluid is conditioned to flow in the direction of the cooling device by a three-way valve.

However, when the battery pack needs to be heated in a low temperature condition, the fluid is adjusted to flow in the direction of the heater by the three-way valve.

The present invention also provides a device comprising the battery pack temperature controller and the battery pack, wherein the device can be selected from the group consisting of an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device .

Such devices or devices are well known in the art, so a detailed description thereof will be omitted herein.

As described above, the battery pack heater according to the present invention and the battery pack temperature control system including the phase-change material absorb or emit heat at the time of phase conversion, And the operating performance of the battery pack can be improved in a low temperature condition by heating.

Further, by adding the battery pack to the conventional battery pack cooling apparatus without any design change, it is possible to reduce the design and manufacturing cost, simplify the structure, improve the safety of the battery pack under various mixed conditions such as high temperature and low temperature, So that it is possible to exert the operating performance.

1 is a schematic view of a conventional vehicle battery pack cooling apparatus;
2 is a schematic diagram of a battery pack heater according to one embodiment of the present invention;
3 is a schematic diagram of a battery pack heater according to another embodiment of the present invention;
FIGS. 4 to 6 are schematic views showing the structure and operation state of a battery pack temperature control system according to an embodiment of the present invention; FIG.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited by the scope of the present invention.

2 is a schematic diagram of a battery pack heater according to an embodiment of the present invention.

2, a battery pack heater 200 according to the present invention includes a first storage member 203 having a phase change material, a heating member 201 and an active member 202 sealed in a sealed state, And a second storage member 204 having a first storage member 203 therein.

The heating member 201 may be connected to an external power source (not shown) through an electrical connecting member 205 and may be heated when electricity is applied to induce a phase change from a solid phase to a liquid phase .

The active member 202 is electrically connected 206 to an external control device (not shown) such as a BMS and is electrically or physically connected to the phase change material by an electrical signal of the external control device at low temperature A stimulus is applied to induce phase transformation from a liquid phase to a solid phase.

Since the phase-change material undergoes repeated phase transformation from a liquid phase to a solid phase and from a solid phase to a liquid phase, the volume of the phase change material varies with the change of the physical arrangement of the molecules, And is made of an elastic material whose size can be changed according to the volume change of the conversion material.

An inlet 207 and an outlet 208 are formed on the wall surface of the second storage member 204 so that the fluid can flow with the external battery pack.

3 is a schematic diagram of a battery pack heater according to another embodiment of the present invention.

The battery pack heater 300 further includes a baffle 302 for heat exchange of fluid flowing on the inner surface of the second storage member 301.

In this case, the baffle 302 has a helical structure that surrounds the outer surface of the first storage member 303 on the inner surface of the second storage member 301, so that the fluid flows from the first storage member 303 to the second storage member 303, It is possible to uniformly flow the inner space 304 between the storage members 301 and to maximize heat exchange efficiency.

The fluid introduced into the second storage member 301 through the inlet 305 after the heat exchange with the external battery pack flows into the internal space 304 between the first storage member 303 and the second storage member 301, And at this time, the fluid comes into contact with all the outer surfaces of the first storage member 303, thereby maximizing the heat exchange efficiency. The fluid having undergone the heat exchange is discharged to the battery pack again through the discharge port 306, thereby heating the battery pack to a desired temperature.

4 to 6 are schematic diagrams showing the structure and operating state of the battery pack temperature control system according to one embodiment of the present invention.

Referring to FIG. 4, the battery pack temperature control system 400 includes a battery pack heater 401 including a phase change material together with a conventional battery pack cooling apparatus 402.

In this case, the battery pack heater 401 and the battery pack cooling apparatus 402 are connected to the battery pack 405 by pipes 403a, 403b, 404a, and 404b circulating the respective devices, The pipes 403a, 403b, 404a and 404b circulating through the cooling device 401 and the cooling device 402 are connected to the pipe 406a flowing into the battery pack 405 and the pipe 406b discharged from the battery pack 405, Directional valves 407a and 407b.

The three-way valves 407a and 407b regulate the flow direction of the fluid in the direction of the cooling device 402 or the heater 401. In general, the three-way valves 407a and 407b open in the direction of the battery pack cooling device 402, Thereby cooling the pack 405.

The fluid flows by the circulation pump 408 and the cool fluid 409a discharged from the cooling device 402 flows into the battery pack 405 through the first valve 407a and the heat exchange in the battery pack 405 And the battery pack 405 is cooled. The battery pack 405 and the fluid 409b heated after the heat exchange flows into the cooling device 402 through the pipes 403b and 406b to be heat-exchanged and cooled.

The battery pack temperature control system 400 includes a battery pack heater 401 in addition to the battery pack cooling apparatus 402 and a structure for heating the battery pack 405 by the battery pack heater 401 in a low- Is shown in Fig.

5, when the apparatus including the battery pack temperature control system 500 is operated in a low temperature condition, first, the temperature sensors 503a and 503b provided in the battery pack 505 and the heater 501 Measure the temperature.

If it is determined that the battery pack 501 needs to be heated at a low temperature, the external control device sends an electrical signal to the active member in the battery pack heater 502, By applying physical stimulation, the phase change material induces phase transition from liquid phase to solid phase and releases heat.

In this case, the three-way valves 504a and 504b are adjusted in the direction of the heater 502 in the direction of the cooling device 505. [

The fluid 506a heated by phase transformation of the phase change material contained in the battery pack heater 502 flows into the battery pack 501 through the pipes 507a and 508a and flows into the low temperature battery pack 501, And the battery pack 501 is heated.

The fluid 506b cooled after the heat exchange with the battery pack 501 flows into the heater 502 through the pipes 507b and 508b and is heat-exchanged and heated.

When the battery pack 501 is heated to a desired temperature, the directions of the three-way valves 504a and 504b are adjusted again toward the cooling device 505 so that the fluid flows toward the cooling device 505, The pack temperature control system 505 serves as a general cooling device.

In addition, the phase change material in the battery pack heater 502 is converted from a liquid phase in an unstable state to a solid state in a stable state while releasing heat, thereby preventing overheating and malfunction of the battery pack heater 502 during operation of the apparatus, Lt; / RTI >

When the operation of the apparatus including the battery pack temperature control system 500 is stopped, the battery pack 501 is connected to an external power source to be charged, and the battery pack 501 is charged by the external power source A schematic diagram is shown in Fig.

Referring to FIG. 6, after the operation of the battery pack temperature regulation system 600 is stopped, the battery pack 601 is connected to the external power source 603 by the electrical connection member 602a and is charged.

At this time, the heating member of the battery pack heater 604 is also connected to the external power source 603 like the battery pack 601 by the electrical connecting member 602b.

The heating member connected to the external power source 603 is made of nichrome (Ni-Cr), iron chromium (Fe-Cr), or iron chromium aluminum (Fe-Cr-Al) , And induces a phase transformation from a solid phase to a liquid phase with respect to the phase change material in the heater.

The phase-change material converted from the solid phase to the liquid phase accumulates latent heat, thereby causing a phase change from a liquid phase to a solid phase again by stimulation of the active member when the battery pack heater 604 is restarted, .

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (24)

A phase change material (PCM) that undergoes phase change by temperature conversion or stimulation and absorbs or releases heat during phase transformation;
A heater heated upon application of electricity to induce a phase transformation from phase A to phase B of the phase change material;
An activator that applies an electrical or physical stimulus to cause phase transformation of the phase change material from the B phase to the A phase;
A first reservoir for sealing the phase change material, the heating member and the active member in a sealed state;
A second storage member having a first storage member embedded therein such that fluid can flow through the inlet and the outlet;
Wherein the battery pack heater comprises: The battery pack heater according to claim 1, wherein the A phase is a solid phase and the B phase is a liquid phase. The battery pack heater of claim 1, wherein the lowest melting point of the phase change material is about 40 degrees Celsius. The battery pack heater according to claim 1, wherein the phase change material has a latent heat per unit mass of 150 to 500 kJ / kg. The method of claim 1, wherein the phase change material is selected from the group consisting of paraffin, polyethylene glycol, supersaturated Na ₂ S ₂ O ₃ .5H ₂ O, CH ₃ CO ₂ Na 3H ₂ O, and MgCl ₂ .6H ₂ O And the battery pack heater is at least one selected from the group consisting of: The battery pack heater according to claim 1, wherein the heating member is a heating coil.  The battery pack heater of claim 6, wherein the heating coil is made of Ni-Cr, Fe-Cr, or Fe-Cr-Al. The battery pack heater according to claim 1, wherein the active member is electrically connected to an external control device, and applies an electrical or physical stimulus to the phase-change material by an electrical signal of the external control device. The battery pack heater of claim 8, wherein the external control device is a battery management system (BMS). The battery pack heater of claim 1, wherein the first storage member is made of an elastic material whose size can be changed according to volume change of phase change material during phase conversion. The battery pack heater according to claim 1, wherein the first storage member or the second storage member has a cylindrical shape, an elliptical shape, or a polygonal shape in cross section. The battery pack heater of claim 1, wherein the first storage member and the second storage member have the same shape. The battery pack heater of claim 1, wherein the first storage member is located at the center of the second storage member. 2. The battery pack heater of claim 1, wherein the second storage member further comprises a baffle for heat exchange of the fluid flowing therein. 15. The battery pack heater of claim 14, wherein the baffle is of a spiral structure wrapping the outer surface of the first storage member on the inner surface of the second storage member. The battery pack heater according to claim 1, wherein the fluid is an antifreeze. The battery pack heater of claim 1, wherein the fluid comprises ethylene glycol. The battery pack heater of claim 1, further comprising a first temperature sensor for measuring the temperature of the fluid. The battery pack temperature control device according to claim 1, further comprising a battery pack heater and a battery pack cooling device. 20. The battery pack according to claim 19, wherein the battery pack heater and the battery pack cooling apparatus are connected to the battery pack by at least one pipe, and the fluid flows through the pipe to heat or cool the battery pack. Regulating device. 21. The apparatus according to claim 20, wherein a direction of flow of the fluid is controlled by a valve installed in the pipe in the direction of the cooling device or the heater. 22. The apparatus of claim 21, wherein the valve is a three-way valve. 20. A device comprising a battery pack temperature regulation device according to claim 19 and a battery pack. 24. The device of claim 23, wherein the device is selected from the group consisting of an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

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