JP2005219579A - Air-conditioning control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-conditioning control device capable of controlling an air-conditioner with excellent energy efficiency. <P>SOLUTION: The air-conditioning control device comprises an air-conditioner 5 having a compressor 6, a condenser 10 and an electric fan 23, improved fuel consumption calculation means 16 and 15 to calculate the fuel consumption to be saved by improving the cooling efficiency through liquefaction promotion in the condenser 10 when the electric fan 23 is operated, fan-driven fuel consumption calculation means 16 and 15 to calculate the fuel consumption required for the operation of the electric fan 23, and a control means 16 to drive the electric fan 23 if the fuel consumption calculated by the improved fuel consumption calculation means is larger than the fuel consumption calculated by the fan-driven fuel consumption calculation means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air conditioning control device that controls an air conditioner that generates cold using the output of an internal combustion engine mounted on a vehicle.

  Currently, most of the vehicles on the market are equipped with air conditioners. The air conditioner heats the interior of the vehicle using heat generated by the engine, or cools the interior of the vehicle by generating cold. Alternatively, it is also used when clouding the windshield by the dehumidifying function. In general, cold air generation by an air conditioner uses the heat of vaporization of a refrigerant. A compressor-condenser-evaporator is placed on the annular refrigerant circulation path so that the refrigerant is compressed by the compressor so that it can be easily liquefied. Is generated.

The output of the engine, which is an internal combustion engine, is used to compress the refrigerant in the compressor. For this reason, it is also known that the drive of the compressor is efficiently controlled to improve fuel consumption. ([Patent Document 1]).
JP 2002-36903 A

  At the time of liquefaction of the refrigerant in the condenser, the refrigerant is liquefied by cooling with a traveling wind or the like. However, the refrigerant cannot be sufficiently cooled during a traffic jam or at a constant speed. For such a case, an air conditioner in which an electric fan is provided and cooling is performed by blowing air from the electric fan is also common. However, since electric power is consumed to drive the electric fan, power consumption increases as the frequency of driving the electric fan increases. An increase in power consumption results in a decrease in driving power of the engine that generates power, leading to deterioration in fuel consumption. Therefore, the objective of this invention is providing the air-conditioning control apparatus which can control an air conditioner efficiently.

  The air conditioning control device according to claim 1 controls an air conditioner that generates cold using the output of an internal combustion engine mounted on a vehicle, and the air conditioner compresses the refrigerant with a compressor that compresses the refrigerant. Consumption of fuel that is saved by improving the cooling efficiency by accelerating the liquefaction in the condenser when the electric fan is activated, and the electric fan that promotes the liquefaction of the refrigerant in the condenser The fuel consumption amount calculated by the improved fuel consumption amount calculating means, the fan driving fuel consumption amount calculating means for calculating the fuel consumption amount consumed by the operation of the electric fan, and the fuel consumption amount calculated by the improved fuel consumption amount calculating means When the electric power consumption is greater than the fuel consumption calculated by the fan-driven fuel consumption calculation means, the electric fan is driven. It is characterized in that a control means.

  According to a second aspect of the present invention, the air conditioning control device according to the first aspect further includes a battery that supplies electric power to the electric fan, and the control device refers to the storage state of the battery and the electric fan. It is characterized by driving.

  According to a third aspect of the present invention, the air conditioning control device according to the first or second aspect further comprises an efficiency change calculation means for calculating a change in energy consumption efficiency caused by operating the electric fan. The fuel consumption amount calculating means calculates a fuel consumption amount saved by the efficiency improvement when the efficiency change calculated by the efficiency change amount calculating means is an efficiency improvement.

  In the air conditioning control device according to claim 1, while the electric fan is driven to promote the liquefaction of the refrigerant in the condenser to predict the fuel consumption that can be saved by improving the cooling efficiency, the electric fan is driven. The required fuel consumption is predicted, and the electric fan is driven based on these two fuel consumptions so as not to deteriorate the fuel consumption. Thereby, the air conditioner can be controlled with energy efficiency.

  According to the second aspect of the present invention, when the electric fan is controlled, it is possible to realize further improvement in energy efficiency by referring to the storage state of the battery as the power supply source.

  According to the third aspect of the present invention, when predicting the amount of fuel consumed for improving the cooling efficiency by driving the electric fan, first, the energy consumption efficiency (COP) is calculated, and if this COP is improved, Calculate the fuel consumption saved. The change in the COP is calculated to determine whether or not the cooling efficiency is improved, and the fuel consumption that can be saved only when the efficiency can be expected is predicted. For this reason, it is possible to improve control accuracy and reduce execution of unnecessary arithmetic processing.

  An embodiment of the control device of the present invention will be described below. The main components of a vehicle having the control device of this embodiment are shown in FIG. The driving force that drives the vehicle 1 is generated by the engine 2 that is an internal combustion engine. The engine 2 itself is a known general engine. The output of the engine 2 is transmitted to drive wheels via a transmission 3 and a differential gear (not shown) to drive the vehicle 1. Further, an alternator (generator) 4 that is driven by utilizing a part of the output of the engine 2 and a compressor 6 of the air conditioner 5 are attached to the engine 2. The alternator 4 and the compressor 6 are auxiliary machines that generate energy using the output of the engine 2.

  The electric power generated by the alternator 4 is used as it is by the engine 2 and other auxiliary machines as well as for charging the battery 7. The air conditioner 5 introduces air cooled by a heat exchanger 8 serving as a heat source or air heated by a heater core (not shown) serving as a heat source into the vehicle interior by a blower fan 9, thereby cooling and heating the vehicle interior. (Or dehumidification). In the air conditioner 5, one refrigerant circulation system is formed by the compressor 6, the condenser 10, the cool storage unit 12 of the heat accumulator 11, and the compressor 6. Further, another circulation system is formed between the cold storage unit 12 and the heat exchanger 8. That is, the cold generated by the air conditioner 5 is temporarily stored in the cold storage unit 12, and the cold heat of the cold storage unit 12 is introduced into the vehicle via the heat exchanger 8.

  Although the cold storage part 12 mentioned above is a part which stores the produced | generated cold heat, the thermal storage 11 is provided with the warm storage part 13 which stores warm heat. The warm storage unit 13 has a circulation system in which the coolant of the engine 2 is branched and circulated, and stores the heat of the coolant. Moreover, the warm storage part 13 has another circulation system between the heater core (not shown) mentioned above. That is, the warm storage unit 13 temporarily stores the warm heat of the coolant of the engine 2, and the warm heat of the warm storage unit 13 is introduced into the vehicle via the heater core. The heat accumulator 11 and the battery 7 described above function as a storage device 14 that stores energy.

  The generation of cold heat in the air conditioner 5 will be briefly described. The refrigerant is compressed by the compressor 6, the heat is taken away by the condenser 10, the refrigerant is liquefied, and the refrigerant is easily vaporized by the expansion valve built in the cool storage unit 12, and the coolant is vaporized by the cool storage unit 12. The regenerator material inside the regenerator 12 is cooled by the heat of vaporization at this time. An electric fan 23 is provided along with the capacitor 10. As described above, the traveling wind is used when the refrigerant is liquefied in the condenser 10, but the refrigerant cannot be sufficiently cooled when the vehicle is congested or travels at a low speed. For this reason, the electric fan 23 is provided and the refrigerant is cooled by blowing air from the electric fan 23.

  The cold storage unit 12 accumulates cold heat by keeping the temperature of the internal cold storage material low. The refrigerant discharged from the cold storage unit 12 is compressed again by the compressor 6 and circulates repeatedly through the compressor 6 -the condenser 10 -the cold storage unit 12 described above. Further, the inside of the circulation pipe between the cold storage unit 12 and the heat exchanger 8 is also filled with the refrigerant, and the cold heat stored in the cold storage unit 12 is transmitted to the heat exchanger 8 in the passenger compartment by the circulation of the refrigerant. It is done. The cold heat of the heat exchanger 8 is introduced into the vehicle interior by the blower fan 9 described above. As the refrigerant filled in the circulation pipe between the cold storage section 12 and the heat exchanger 8 described above, liquid such as water, brine (brine), ethylene glycol solution, or gas such as carbon dioxide is used. The cold storage unit 12 includes a temperature sensor that detects an internal cold storage material temperature and a refrigerant temperature. The cold storage unit 12 also includes a pressure sensor that detects the pressure of the refrigerant. Furthermore, the heat exchanger 8 also incorporates a temperature sensor.

  The above-described compressor 6 of the present embodiment is of an externally controlled variable displacement type, and can continuously variably control the refrigerant compression and discharge amount by an external signal (DUTY signal). The structure is of a known general swash plate type, and the capacity is changed by changing the inclination of the swash plate. The compressor 6 can have a capacity of zero so that the refrigerant is not discharged, and does not require a clutch or the like. The alternator 4 described above is connected to an electronic control unit (ECU) 15 that controls the engine 2, and its power generation amount is variably controlled. The above-described compressor 6 is connected to an air conditioner ECU 16 that controls the air conditioner 5, and the refrigerant protrusion amount (compressor capacity) is variably controlled. The engine ECU 15 and the air conditioner ECU 16 are connected to an integrated ECU 17 that comprehensively controls various controls of the entire vehicle 1. The ECUs 15 to 17 coordinate the control of the engine 2, the power generation control by the alternator 4, and the air conditioning control by the air conditioner 5. The battery 7 is also connected to the integrated ECU 17, and the voltage of the battery 7 is monitored by the integrated ECU 17.

  Furthermore, the temperature sensor and pressure sensor incorporated in the cold storage unit 12 are also connected to the air conditioner ECU 16, and the refrigerant temperature and pressure of the cold storage unit 12 are monitored by the air conditioner ECU 16. The electric fan 23 and the blower fan 9 described above are also connected to the air conditioner ECU 16, and the driving of these fans 23, 8 is controlled by the air conditioner ECU 16. Furthermore, a wheel speed sensor 18 and an outside air temperature sensor 19 are also connected to the integrated ECU 17. The wheel speed sensor 18 is attached to each wheel and detects the number of rotations of each wheel. The speed of the vehicle 1 can also be detected from the detection result of the wheel speed sensor 18. The outside air temperature sensor 19 detects the temperature outside the vehicle.

  The air conditioner ECU 16 is also connected with a vehicle interior temperature sensor 20 for detecting the temperature in the vehicle interior and an operation panel 21. The operation panel 21 sets the set temperature, the air blowing mode, the air volume, and the like. Further, the engine ECU 15 is also connected to a navigation system 22 mounted on the vehicle 1. The navigation system 22 incorporates a storage medium such as a hard disk or a DVD disk that stores road / terrain information and other information (facility information, etc.). The information in this recording medium is information (running environment status) regarding non-variable intersections (signals), presence / absence of level crossings, road gradient (terrain), altitude, etc. that do not change in a short time. In addition, the navigation system 22 has a communication function, and can acquire from the outside of the vehicle 1 a traveling environment situation that can fluctuate in a short time, such as weather (weather) or a traffic jam situation. The non-variable driving environment information described above may be acquired by the communication function.

  The communication function may be a communication function that completes itself, such as a dedicated communication interface, or may use a mobile phone or the like. Furthermore, so-called VICS, optical beacons, FM communication, and the like are one of the communication functions described here. Moreover, if the destination is set, it is also possible to acquire travel environment information over the entire section of this route along with the recommended route. In addition, the own vehicle position of the vehicle 1 can be detected using GPS, a gyro, or the like. The engine ECU 15 can acquire the above-described traveling environment situation from the navigation system 22 as information. The navigation system 22 functions as an environmental status acquisition unit.

  Next, air conditioning control (control of the electric fan 23) using the above-described apparatus will be described. A control flowchart according to the present embodiment is shown in FIG. First, as shown in FIG. 2, it is determined whether or not cold air is being generated by the air conditioner 5 (step 200). As described above, the air conditioner 5 of the present embodiment can store cold energy in the cold storage unit 12. For this reason, when the cooling of the passenger compartment is not carried out, cold heat is generated in advance and stored in the cold storage unit 12. For example, when the information acquired by the navigation system 22 described above is predicted to cool the interior of the vehicle after a while, or after a while, the output demand for the engine 2 increases, and the generation of cold generates an output source. If you do not want to make it happen, you can generate and store cold in advance.

  If step 200 is negative, there is no need to drive the electric fan 23 associated with the capacitor 10, and the control of the flowchart of FIG. On the other hand, when step 200 is affirmed, first, the outside air temperature is read by the outside air temperature sensor 19 (step 205), and the vehicle speed is detected from the detection result of the wheel speed sensor 18 (step 210). Further, the refrigerant pressure is detected by a pressure sensor built in the cold storage unit 12 (step 215). After step 215, the energy storage status in the storage device 14 is acquired (step 220). First, the calculation method of the cold storage state in the cold storage part 12 is shown. An explanatory diagram relating to this is shown in FIG.

As shown in FIG. 3, the refrigerant temperature before the cold storage unit 12 is T1, the refrigerant temperature after the cold storage unit 12 is T1 ′, the flow volume is M1, and the heat quantity of the refrigerant is Q1. Similarly, the temperature of the cold storage material in the cold storage unit 12 is T2, the volume thereof is M2, and the amount of heat of the cold storage material is Q2. Moreover, the temperature before the heat exchanger 8 of the refrigerant circulating between the cold storage unit 12 and the heat exchanger 8 is T3, the temperature after the heat exchanger 8 is T3 ′, and the flow volume is M3. Q3. Further, the temperature of the heat exchanger 8 is T4, and the air conditioning heat load is Q4 as described above. If it does in this way, calorie | heat amount Q2 is shown by following formula (I) or formula (II). Formula (I) is for determining Q2 based on temperature, and Formula (II) is for determining Q2 based on the amount of heat. T2start is the temperature of the cold storage material in the initial (normal temperature) state.
Q2 = (T4-T2) × M2 (I)
Q2 = Q1-Q3-[(T2start-T4) * M2]
= [(T1′−T1) × M1] − [(T3′−T3) × M3] − [(T2start−T4) × M2] (II)

In addition, here, when the amount of power stored in the battery 7 is also acquired, the following calculation is performed. An explanatory diagram relating to this is shown in FIG. When the voltage of the battery 7 is V, the stored energy is E, t1 to tn are the control time, i1 is the charging current of the battery 7, and i2 is the discharging current of the battery 7, the energy (storage amount) E is expressed by the following formula ( III).
E = [(i1-i2) * V * t1] + [(i1-i2) * V * t2] + ... + [(i1-i2) * V * tn] (III)

  After step 220, the amount of heat that can be dissipated by the capacitor 10 is estimated using the maps of FIGS. 5 and 6 (step 225). The map in FIG. 5 shows the heat radiation amount of the capacitor with respect to the outside air temperature. As described above, since the outside air is applied to the condenser 10 to cool the refrigerant, the amount of heat that can be radiated by the condenser 10 increases as the outside air temperature decreases. FIG. 6 shows the heat dissipation amount of the capacitor with respect to the vehicle speed. In the map of FIG. 6, a line of the heat radiation amount of the capacitor only by the electric fan is also shown. As apparent from FIG. 6, if the electric fan is not used, the heat dissipation amount of the capacitor increases as the vehicle speed increases and the traveling wind sufficiently hits the capacitor 10. When the vehicle speed is low, it can also be seen that the amount of heat radiation can be increased by driving the electric fan (see the hatching section). However, when the vehicle speed is equal to or higher than a certain value Sth, there is no merit of driving the electric fan. Here, in FIG. 5 and FIG. 6, the heat release amount with respect to the outside air temperature and the heat release amount with respect to the vehicle speed are shown separately, but a map in which these are integrated may be created.

  After step 225, based on the heat radiation amount estimated in step 225 (when the electric fan is driven or not), the change in COP (Coefficient of Performance = energy consumption efficiency) due to the driving of the electric fan is changed. It calculates | requires based on the map of FIG. 7 (step 230). The COP is obtained by (cooling capacity [watt]) / (power consumption [watt]). When the COP change is obtained, it is determined whether or not the COP change is a change toward the efficiency improvement side (step 235). If step 235 is negative and the efficiency does not improve even when the electric fan is driven, the control of the flowchart of FIG. 2 is finished as it is.

  If step 235 is affirmed and the amount of heat release increases by driving the electric fan 23 and the COP is improved, then the fuel consumption that can be saved by the improvement of the COP is calculated (step 240). At this time, the map of FIG. 8 is used. The map in FIG. 8 shows the relationship between the COP and the amount of fuel consumed. The higher the efficiency (COP), the smaller the amount of fuel consumed. In the map of FIG. 8, the amount of fuel that can be saved by improving the COP is indicated by A. In FIG. 8, X is a COP when the electric fan 23 is not driven, and Y is a COP when the electric fan 23 is driven.

  Next, the fuel consumption required for driving the electric fan 23 is obtained using the map of FIG. 9 (step 245). The amount of fuel consumed increases as the power consumption of the electric fan increases. In the map of FIG. 9, B represents the amount of fuel consumption that increases as the electric fan 23 is driven. Then, it is determined whether A> B is satisfied (step 250). In other words, here, the amount of fuel consumed that can be saved by improving the efficiency by driving the electric fan 23 is compared with the amount of fuel consumed to drive the electric fan 23. If step 250 is negative, the amount of fuel consumed increases due to the driving of the electric fan 23, and thus the control of the flowchart of FIG. If step 250 is affirmed, the amount of fuel consumed can be saved by driving the electric fan 23, so the electric fan is driven (step 255).

  Here, the drive control of the electric fan 23 may be performed based on the charged amount of the battery 7 obtained in step 220 described above. For example, when the electric power consumed by driving the electric fan 23 is smaller than the remaining amount of power stored in the battery 7, it is conceivable that the electric fan 23 is actively driven to increase the cold storage amount as much as possible. Alternatively, when the power consumption by driving the electric fan 23 is large and the deterioration of fuel consumption is promoted, it is optimal to reduce the operating rate of the electric fan 23 and prevent the deterioration of fuel consumption even if the amount of cold storage decreases. Take control.

  In addition, when the electric fan 23 is capable of controlling the amount of air flow (= power consumption amount) by a control signal (DUTY signal) to be given, the air volume is variably controlled according to the amount of cold storage or the amount of electricity stored. Also good. Further, when the vehicle interior cooling is performed, the electric fan 23 may be driven to ensure the cooling performance even if the fuel efficiency is deteriorated. Even in such a case, as in the present embodiment, the amount of fuel that can be saved by improving the efficiency by driving the electric fan 23 is compared with the amount of fuel that is required to drive the electric fan 23. Efficiency can be improved by controlling the electric fan 23 based on the comparison.

  In addition, the control apparatus of this invention is not limited to embodiment mentioned above. For example, the drive control of the electric fan 23 in the above-described embodiment has been described considering only the cooling of the capacitor 10. However, there may be a case where the conditioner of the air conditioner and the radiator that cools the engine coolant are stacked and cooled by an electric fan. In such a case, the electric fan 23 may be driven from the relationship with the engine coolant temperature. In the above-described embodiment, the integrated ECU 17, the engine ECU 15, and the air conditioner ECU 16 share the control, and these ECUs perform efficiency change calculation means, fan drive fuel consumption calculation means, fan drive fuel consumption. It functions as a quantity calculation means and a control means. However, how to share the functions of these ECUs is not limited to the above-described embodiment. Moreover, when using ECU for the control apparatus of this invention, it does not mean that the number must be three.

It is a block diagram which shows the structure of the vehicle which has one Embodiment of the control apparatus of this invention. It is a control flowchart by one Embodiment of the control apparatus of this invention. It is explanatory drawing regarding energy storage amount (cold storage amount) calculation. It is explanatory drawing regarding energy storage amount (electric storage amount) calculation. It is a map which shows the relationship between external temperature and a capacitor | condenser heat dissipation. It is a map which shows the relationship between a vehicle speed and a capacitor | condenser heat dissipation. It is a map which shows the relationship between COP and a capacitor | condenser heat dissipation. It is a map which shows the relationship between COP and fuel consumption. It is a map which shows the relationship between electric fan drive power consumption and fuel consumption.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine (internal combustion engine), 4 ... Alternator, 5 ... Air conditioner, 6 ... Compressor, 7 ... Battery, 8 ... Heat exchanger, 9 ... Blower fan, 10 ... Condenser, 11 ... Heat accumulator, 12 ... cool storage part, 15 ... engine ECU (efficiency change calculation means, fan drive fuel consumption calculation means, fan drive fuel consumption calculation means, and control means), 16 ... air conditioner ECU (efficiency change calculation means, fan drive) Fuel consumption calculation means, fan drive fuel consumption calculation means, and control means), 17... Integrated ECU (efficiency change calculation means, fan drive fuel consumption calculation means, fan drive fuel consumption calculation means, and control) Means), 23... Electric fan.

Claims (3)

In an air conditioning control device that controls an air conditioner that generates cold using the output of an internal combustion engine mounted on a vehicle,
The air conditioner includes a compressor that compresses the refrigerant, a condenser that liquefies the refrigerant compressed by the compressor, and an electric fan that promotes liquefaction of the refrigerant in the condenser.
Improved fuel consumption calculation means for calculating fuel consumption saved by improving cooling efficiency by promoting liquefaction in the capacitor when the electric fan is operated;
Fan-driven fuel consumption calculating means for calculating fuel consumption required for the operation of the electric fan;
Control means for driving the electric fan when the fuel consumption calculated by the improved fuel consumption calculation means is greater than the fuel consumption calculated by the fan drive fuel consumption calculation means. An air conditioning control device characterized by that.   The air conditioning control according to claim 1, further comprising a battery that supplies electric power to the electric fan, wherein the control device drives the electric fan with reference to a storage state of the battery. apparatus. The apparatus further comprises an efficiency change calculation means for calculating an energy consumption efficiency change by operating the electric fan,
2. The improved fuel consumption calculating means calculates a fuel consumption saved by the efficiency improvement when the efficiency change calculated by the efficiency change calculating means is an efficiency improvement. Or the air-conditioning control apparatus of 2.

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