JP2003175720A - In-vehicle air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-vehicle air-conditioning system actuated by using electric energy obtained from an exhaust heat energy of an engine cooling circuit due to thermoelectric generation, on the basis of thermoelectric heating/ cooling. <P>SOLUTION: In this on-vehicle air-conditioning system, for example, by making use of thermoelectric generating using a P-N thermoelectric element shown in Fig. (c), exhaust heat from an on-vehicle engine is collected so as to generate electricity by thermoelectric exchange. A thermoelectric air conditioner is operated by the generated electricity. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-vehicle air conditioning system which operates by generating electric power from exhaust heat of an in-vehicle engine by thermoelectric conversion technology based on thermoelectric heating and cooling.

2. Description of the Related Art In a conventional vehicle air conditioning system, a part of the electric power generated from the vehicle alternator is used for operating the vehicle air conditioning system. The alternator converts some of the mechanical energy produced by the engine into electrical energy. As a result, that part of the electrical energy used by the air conditioning operation is lost from the mechanical energy produced by the engine. Current,
The vehicle air conditioning system is based on a gas compression cooling cycle. In the gas compression cooling cycle, the heat medium used as a refrigerant is not environmentally friendly, and recently, an alternative means of cooling is being sought. In the past, patents relating to in-vehicle air conditioning systems have been proposed (for example, Japanese Patent Laid-Open No. 11-342731). There, solar cells are used to convert solar energy into electrical energy, and the generated electrical energy either directly drives the vehicle-mounted air-conditioning system or stores that electrical energy and the vehicle-mounted air-conditioning system Is used to operate an air conditioning system that utilizes electrical energy from its battery to reduce the load on the power of the motor engine during operation.

However, in the case of solar power generation, the density of solar energy is very low even at its maximum intensity, and there is a space limitation, so it is sufficient to operate the air conditioning system. It is impossible to secure electrical energy. In addition, variations in solar energy density and seasonal effects throughout the day are discussed above with respect to achieving the goal of using little mechanical energy generated by the onboard engine to operate the onboard air conditioning system. Systems are not effective. In passenger cars, approximately 70% of the thermal energy generated by combustion of fuel in the engine
Is wastefully released into the atmosphere. Approximately 50% of this unused heat energy is released as exhaust gas, and the remaining 50% is removed from the engine body by the cooling water and released into the atmosphere through the radiator. A number of patent applications have been published regarding the conversion of the thermal energy emitted from the vehicle-mounted engine together with the exhaust gas into electric energy. However, the waste heat energy of another part discharged from the engine cooling circuit is not utilized for beneficial effects. Appropriate use of the waste heat energy can solve the problem of the solar-powered on-vehicle air conditioning system. The purpose of the present invention is to
It is an object of the present invention to provide an in-vehicle air conditioning system which operates based on thermoelectric heating and cooling, and by utilizing electric energy obtained from exhaust heat energy of a cooling circuit of an engine by thermoelectric generation.

(1) A first aspect of the present invention relates to an in-vehicle air conditioning system, which utilizes a thermoelectric cooling device (Peltier effect) to cool a passenger space, and a thermoelectric generator. It utilizes the electric power generated by the unused exhaust heat generated from the combustion of fuel in the engine. (2) According to the invention of claim 2, in the vehicle-mounted air conditioning system according to claim 1, when the thermal energy stored in the heat storage material can be used for power generation and the vehicle is not in operation,
A feature is that a latent heat storage device is incorporated in the vehicle-mounted engine cooling circuit so that the same thermal energy can be used for operating the vehicle-mounted air conditioning system. (3) The present invention according to claim 3 is the vehicle-mounted air conditioning system according to claim 1 or 2, wherein a temperature sensor for measuring an air temperature in a passenger space and a current flow to the thermoelectric cooling unit are restricted. Further, it is characterized by incorporating a control unit for regulating the cooling effect in consideration of the difference between the set temperature and the measured temperature.

DETAILED DESCRIPTION OF THE INVENTION Three major thermoelectric applications are shown in FIG. These are thermoelectric cooling, thermoelectric heat pumps, and thermoelectric generation. As shown in FIG. 1, P- of the thermoelectric module
When electricity flows counterclockwise through the N thermoelectric element, the top plate becomes cold due to the Peltier effect. This is thermoelectric cooling. The principle of thermoelectric heating is similar to thermoelectric cooling described above, except that the current flows in a clockwise direction.
When a temperature difference is applied between the top plate and the bottom plate, a voltage develops due to the Seebeck effect. That voltage is used to power an external load. With respect to claim 1, as shown in FIG. 2, the thermoelectric module 3 is arranged on the body of the engine 1 and on the outer surface of a cooling liquid pipe 4 which carries the heated heating medium from the engine 1 towards the radiator 5. . In the case of an in-vehicle engine, the surface of the engine block reaches a temperature of about 100 ° C. when the engine 1 is operating. The air temperature around it is believed to be about 40 ° C. Then, a temperature difference of about 60 ° C. is introduced on both sides of said thermoelectric module 3. Due to the temperature gradient, heat flows through the thermoelectric module 3, and part of the heat is converted into electricity by thermoelectric conversion. Similarly, the cooling fluid coming out of the engine 1 usually reaches a temperature of about 100 ° C. and, in the same way as already explained, electrical energy was mounted on the pipes which guide the heated engine cooling water to the radiator. Electricity is generated by the heat flowing through the thermoelectric module 3. The electric energy generated in this way is also used to charge the in-vehicle battery that is continuously supplied to the in-vehicle air conditioning system. The on-vehicle air conditioning system described above is composed of two concentric ducts as shown in FIG. A fan 7 mounted on the inlet side of the concentric duct discharges air, and the discharged air flows through both ducts. The inner duct 8 allows air to flow into the passenger space of the vehicle while the air flowing through the outer duct 9 is discharged to the outside of the passenger space. The thermoelectric module 10 is attached to the outer surface of the aforementioned inner duct wall portion.
The current from the vehicle battery is the thermoelectric module 10 described above.
Sent to. As already mentioned, depending on the direction of the current flow, the surface of the thermoelectric module 10 in contact with the aforementioned inner duct 8 is heated or cooled, and either hot or cold air is required to meet the requirements inside the passenger space. Dependently, it will flow into the passenger area. With regard to claim 2, inside the vehicle-mounted engine compartment, the effective space for mounting the above-mentioned thermoelectric module is limited.
As a result, during operation of the engine, the transfer area of the thermoelectric module mounted on the pipe of the engine cooling circuit is small and is not sufficient to recover a significant portion of the heat of the cooling water. In order to recover the maximum amount of heat from the engine coolant, a heat energy heat storage device 6 is installed immediately before the radiator 5 as shown in FIG.
The thermoelectric module 3 is attached to the entire outer surface of the thermal energy heat storage device 6 described above. The above-mentioned thermal energy heat storage device 6 includes a solid heat storage material having a melting point close to the temperature of the cooling liquid immediately before the entrance side of the radiator 5. The aforementioned thermal energy heat storage material can exist in either a solid state or a liquid state depending on the amount of energy recovered by the aforementioned thermal energy heat storage device. Since the heat storage material absorbs a considerable amount of heat equal to its latent heat of melting, most of the thermal energy per unit weight of the heat storage material is stored in this way. The thermoelectric module arranged on the outer surface of the thermal energy heat storage device described above generates electricity by the temperature difference between both sides of the thermoelectric module 3. Further, the thermoelectric module continues to generate electricity by using the stored energy remaining in the thermal energy heat storage device even when the vehicle is not in operation. The electricity thus generated is stored in the on-vehicle battery, and the on-vehicle air conditioning system can be operated by using the electric power from the on-vehicle battery even when the vehicle is not in operation. With regard to claim 3, the control system shown in FIG. 5 is incorporated in the above-mentioned vehicle air conditioning system for adjusting the vehicle air conditioning system. As already explained, the electric energy generated by the thermoelectric module is stored in the battery. The electrical energy from the battery is sent to the onboard air conditioning system described above through the control system described above. The control system is
It is composed of a temperature sensor 14, a controller 15, and a pole conversion device 16. The aforementioned temperature sensor 14 measures the temperature in the passenger area of the vehicle. The controller 15 described above
Verifies that the measured temperature matches the predetermined temperature set by the passenger. Based on the difference, the controller 15 described above regulates the flow of current to the thermoelectric module. Thereby, the heating or cooling of the thermoelectric module can be increased or decreased. The controller 15 also controls the polarity of the current to the thermoelectric module depending on whether heating or cooling of the passenger space is required.

The generation of electricity by the unused thermal energy currently discharged from the vehicle-mounted engine through thermoelectric generation, and the use of the generated electricity to operate the vehicle-mounted air conditioning system are caused by the vehicle-mounted engine. It reduces the extra load on the mechanical energy of the vehicle, which can improve the fuel efficiency of the vehicle.

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of thermoelectric conversion technology, in which (a) is a thermoelectric cooler, (b) is a thermoelectric heat pump, and (c) is a thermoelectric generator.

FIG. 2 is a diagram of a cooling circuit of an in-vehicle engine having a thermoelectric module.

FIG. 3 is a view of a vehicle-mounted thermoelectric air conditioner, (a) is a side view,
(b) is a front view.

FIG. 4 is a diagram of a cooling circuit of an in-vehicle engine having a thermoelectric module and a thermoelectric energy heat storage device.

FIG. 5 is a diagram of an in-vehicle air conditioning control system.

[Explanation of symbols]

1. Engine 2. Engine cooling jacket 3. Thermoelectric module 4. Coolant pipe 5. radiator 6. Heat storage device 7. Fan 8. Inside duct 9. Outer duct 10. Thermoelectric module 11. Thermoelectric generator 12. DC-DC converter 13. Battery 14. Temperature sensor 15. Controller 16. Pole converter 17. Thermoelectric cooler / heater

Claims (3)

[Claims] 1. A thermoelectric cooling device (Peltier effect) is used to cool a passenger space, and electric power generated by an unused waste heat generated from combustion of fuel in an engine by a thermoelectric generator is used. An in-vehicle air conditioning system characterized by 2. The on-vehicle air conditioning system according to claim 1, wherein the heat energy stored in the heat storage material can be used for power generation, and when the vehicle is not in operation, the heat energy is stored in the on-vehicle air conditioning system. To be available for driving,
An in-vehicle air conditioning system characterized by incorporating a latent heat storage device in an in-vehicle engine cooling circuit. 3. The on-vehicle air conditioning system according to claim 1 or 2, wherein a temperature sensor for measuring an air temperature of a passenger space and a flow of current to a thermoelectric cooling unit are regulated, and a set temperature and its measurement are further controlled. An in-vehicle air conditioning system characterized by incorporating a control unit that regulates the cooling effect in consideration of the difference in temperature.