JP2003148358A - Air conditioner for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration of air conditioning feeling while reducing power consumption of a drive source different from an engine in an air conditioner having a hybrid drive type compressor. SOLUTION: When a vehicle is stopped for waiting for the traffic light to change, or as caught in traffic congestion, an engine is stopped, a motor is started at a prescribed time ΔT after that to drive the compressor, and flow of cooling medium discharged from the compressor is periodically changed to set average cooling medium flow Va circulating in a refrigerator to be smaller than cooling medium flow when the compressor is driven by the engine. The average cooling medium flow Va when the compressor is driven by the motor is set as such a degree that the air conditioning feeling is not largely deteriorated. The maximum cooling medium flow Vmax when the compressor is driven by the motor is set as the lower limit value of the cooling medium flow causing no conspicuous unevenness in flow of cooling medium in an evaporator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle air conditioner, and is particularly effective when applied to an air conditioner equipped with a hybrid drive type compressor.

[0002]

2. Description of the Related Art A hybrid drive type compressor is a utility model registration publication No. 25.
As described in Japanese Patent No. 96291, the compressor is driven by switching between a running engine and an electric motor.

By the way, this hybrid drive type compressor is generally applied to an air conditioner of a vehicle in which the fuel consumption of the vehicle is improved and the exhaust gas is reduced, and a vehicle equipped with the hybrid drive type compressor. The engine drives the compressor when the vehicle is running, and when the vehicle is stopped due to signal waiting or traffic congestion, the engine is stopped to improve vehicle fuel efficiency and reduce exhaust gas while driving the compressor with an electric motor. To maintain the air conditioning capacity.

However, when the compressor is driven by the electric motor, the engine is stopped and the generator is stopped, so that the electric motor must be driven only by the electric power stored in the battery, The amount of power stored in the battery decreases.

Therefore, the present inventors have attempted to reduce the power consumption of the electric motor by driving the compressor by the electric motor, as compared with the case of driving the compressor by the engine. Although an air conditioner that reduces the power consumption of the compressor, that is, the power consumption of the electric motor by reducing the flow rate of the refrigerant that circulates in the refrigerator) was experimentally studied, the following problems newly occurred.

That is, when the flow rate of the refrigerant decreases, the refrigerant flowing in the evaporator flows so as to gather in a passage having a small pressure loss among the many refrigerant passages from the refrigerant inlet to the refrigerant outlet, so that the refrigerant in the evaporator. There will be a noticeable bias in the flow. For this reason, the temperature of the cool air that has passed through the evaporator is different depending on the part of the evaporator that passes through, and the air conditioning feeling deteriorates.

On the other hand, the refrigerant flow rate may be increased to such an extent that the refrigerant flow in the evaporator is not significantly biased, but this means cannot reduce the power consumption of the electric motor.

In view of the above points, the present invention reduces the power consumption of a drive source different from the engine in an air conditioner that drives a compressor by switching between a running engine and a drive source different from the engine such as an electric motor. At the same time, it aims to prevent the air conditioning feeling from deteriorating.

[0009]

In order to achieve the above object, the present invention provides a driving source (200) for traveling and a second driving source (200) different from the driving source (200) for traveling. A compressor (100) that receives power from a drive source (210) to suck and compress the refrigerant, a radiator (110) that cools the refrigerant discharged from the compressor (100), and a refrigerant that flows out from the radiator (110). And a evaporator (1) for evaporating the refrigerant decompressed by the decompressor (120).
30) and a compressor (100) with a second drive source (2
When driven by 10), the flow rate of the refrigerant discharged from the compressor (100) is periodically changed.

Thus, when the compressor (100) is driven by the second drive source (210), the refrigerant flow rate is ensured in the evaporator (130) to such an extent that the refrigerant flow is not significantly biased. However, since the average refrigerant flow rate can be reduced, the power consumption (power consumption) of the motor 210 can be reduced while preventing the air conditioning feeling from deteriorating.

Further, since the power consumption of the second drive source (210) can be reduced, the second drive source can be downsized.

In the second aspect of the present invention, the second drive source (210) is an electric motor, and the second drive source (210) is stopped by the drive source (200) for traveling. After that, when the temperature of the evaporator (130) reaches or exceeds a predetermined temperature, it starts operating.

As a result, the power consumption of the second drive source (210) can be further reduced.

According to the third aspect of the invention, the second drive source (210) is an electric motor, and the second drive source (210) is stopped by the drive source (200) for traveling. It is characterized in that it starts to operate when a predetermined time has elapsed from the time when it was performed.

As a result, the power consumption of the second drive source (210) can be further reduced.

By the way, when the drive source (200) is stopped and the compressor (100) is stopped, the valve of the pressure reducer (120) is closed due to its structure. Therefore, the compressor (10
0) is stopped, the evaporator (130) is cooled according to the refrigerant remaining in the evaporator (130) and the heat capacity of the evaporator (130).
Although the temperature of 0) rises, the invention according to claim 4 is characterized in that the pressure reducing device (120) is provided with throttling means (124) for flowing the refrigerant around the depressurizing device (120). Even if (120) is closed, it is possible to supply the liquid-phase refrigerant to the evaporator (130) through the throttling means (124) due to the residual high-low pressure difference, so that the supplied liquid-phase refrigerant evaporates. Thereby, the temperature rise of the evaporator (130) can be suppressed. Therefore, the second drive source (2
Since the timing of starting 10) can be delayed, the power consumption of the second drive source (210) can be further reduced.

According to the invention described in claim 5, the compressor (10
0) is a variable displacement compressor capable of changing the discharge capacity, and further, when the compressor (100) is driven by the second drive source (210), the compressor (100)
The discharge capacity of is smaller than the maximum discharge capacity.

As a result, the torque required to drive the compressor (100) can be reduced, and the power consumption of the second drive source (210) can be further reduced.

Incidentally, the reference numerals in the parentheses of the above-mentioned means are examples showing the correspondence with the concrete means described in the embodiments described later.

[0020]

1 is a schematic diagram of a vehicle air conditioner (vapor compression refrigerator) according to the present embodiment.
Reference numeral 00 denotes a compressor for sucking and compressing the refrigerant.
Is a running engine 200 and an electric motor 210.
It gets the driving force from and operates.

The motor 210 is integrated with a pulley 230 around which a V-belt 220 that transmits the power of the engine 200 to the compressor 100 is hung.

The radiator (condenser) 110 exchanges heat between the refrigerant discharged from the compressor 100 and the outside air to cool the refrigerant, and the decompressor 120 decompresses and expands the refrigerant flowing out from the radiator 110. The evaporator 130 heat-exchanges the low-pressure refrigerant decompressed by the decompressor 120 and the air blown into the room to evaporate the liquid-phase refrigerant.

In this embodiment, as the decompressor 130, a thermal expansion valve is used which mechanically adjusts the valve opening so that the refrigerant superheat on the outlet side of the evaporator 130 becomes a predetermined value.

Incidentally, the temperature type expansion valve is, as shown in FIG. 2, a saturation pressure due to the refrigerant temperature at the refrigerant outlet side of the evaporator 130 acting on the upper surface side of the diaphragm 121, while
By operating the refrigerant pressure on the refrigerant outlet side of the evaporator 130 and the elastic force of the spring 122 on the lower surface side of the diaphragm 121, the valve body 123 is displaced according to the pressure difference acting on the diaphragm 121, and the valve opening degree is increased. Is to be adjusted.

Further, in FIG. 1, a capillary tube 124 is provided.
Is a throttle means for bypassing the decompressor 120 to flow the refrigerant, and the accumulator 140 separates the refrigerant flowing out of the evaporator 130 into a liquid phase refrigerant and a gas phase refrigerant to store the liquid phase refrigerant, and It is a gas-liquid separating means for causing the phase refrigerant to flow out to the suction side of the compressor 100.

Next, the characteristic operation of this embodiment and its effect will be described.

FIG. 3 is a chart showing changes in the flow rate of the refrigerant circulating in the refrigerator. The compressor 200 is driven by the engine 200 when the vehicle is running, and the engine 200 is stopped when the vehicle is stopped due to a signal waiting or traffic jam. After that, when a predetermined time ΔT has elapsed, the motor 210 is operated to drive the compressor 100, and regardless of the air conditioning load on the evaporator 130,
The average refrigerant flow rate Va circulating in the refrigerator is the engine 20.
When the compressor 100 is driven at 0, the flow rate of the refrigerant discharged from the compressor 100 is periodically changed so that it becomes smaller than the refrigerant flow rate.

Here, the average refrigerant flow rate Va at the time of driving the compressor 100 by the motor 210 is such a refrigerant flow rate that the air conditioning feeling is not significantly deteriorated.
Refrigerant flow rate Vmax when driving the compressor 100 at
Is a lower limit value of the flow rate of the refrigerant in which a significant deviation in the refrigerant flow does not occur in the evaporator 130.

Therefore, it is possible to prevent the refrigerant flow from being significantly deviated in the evaporator 130, so that the power consumption (power consumption) of the motor 210 can be prevented while preventing the air conditioning feeling from being deteriorated. Can be reduced.

Further, since the power consumption (power consumption) of the motor 210 can be reduced, the motor 210 can be downsized.

Further, in this embodiment, when the vehicle is stopped due to a signal waiting or a traffic jam, the motor 210 is operated when a predetermined time ΔT has passed after the engine 200 is stopped, so that the power consumption of the motor 210 is further improved. It can be reduced.

The predetermined time ΔT means the engine 200
Is a time required for the temperature of the evaporator 130 or the temperature of the air immediately after passing through the evaporator 130 to reach a predetermined temperature or higher after the stop, and in the present embodiment, the time obtained in advance in the test (for example, 20 Second) is a predetermined time ΔT.

By the way, when the engine 200 is stopped and the compressor 100 is stopped, the valve of the pressure reducer 120 is closed due to its structure (see FIG. 2). Therefore, the compressor 100
After the stop, the temperature of the evaporator 130 rises according to the refrigerant remaining in the evaporator 130 and the heat capacity of the evaporator 130. However, in the present embodiment, even if the pressure reducer 120 is closed, the remaining high and low pressure difference remains. By capillary tube 124
Since the liquid-phase refrigerant can be supplied to the evaporator 130 via the above, the temperature rise of the evaporator 130 can be suppressed by evaporating the supplied liquid-phase refrigerant. Therefore, since the predetermined time ΔT can be lengthened,
The power consumption of the motor 210 can be further reduced.

Although the liquid-phase refrigerant supplied through the capillary tube 124 may flow out from the evaporator 130, an accumulator 140 is provided between the evaporator 130 and the compressor 100. The liquid-phase refrigerant is never sucked into the compressor 100.

(Other Embodiments) In the above embodiment, the predetermined time ΔT is a fixed time obtained in advance by the test, but the present invention is not limited to this.
After the engine 200 is stopped, the motor 210 may be started when the temperature of the evaporator 130 becomes equal to or higher than a predetermined temperature. Further, the predetermined time ΔT may be changed based on parameters such as the inside temperature, the outside temperature, the amount of solar radiation, and the like regarding the air conditioning load.

Further, in the above embodiment, the compressor 110
Is a fixed displacement type, the compressor 100 is a known variable displacement type compressor, and when the compressor 100 is driven by the motor 210, the discharge capacity of the compressor 100 is set to the maximum discharge capacity. The discharge capacity may be smaller. With this configuration, the torque for driving the compressor 100 can be reduced, and thus the power consumption of the motor 210 can be further reduced.

Further, in the above embodiment, the flow rate of the refrigerant is changed in a rectangular wave, but the present invention is not limited to this, and may be triangular wave, sawtooth wave or sine wave, for example.

Further, in the above embodiment, the maximum flow rate Vmax and the cycle when driving the motor were constant, but the present invention is not limited to this, and the maximum flow rate Vmax and the cycle may be changed.

The decompressor 120 is not limited to the one shown in FIG. 2, but may be another decompression means such as an electric expansion valve or a fixed throttle.

Further, in the above embodiment, the capillary tube 124 is adopted as the throttle means, but the present invention is not limited to this, and a fixed throttle such as an orifice may be used.

An electromagnetic valve is provided on the upstream side of the refrigerant flow in the capillary tube 124 or at the refrigerant outlet of the radiator 110, from when the running engine is stopped until before the motor 210 is operated, that is, when the engine is stopped. Time ΔT 'shorter than the predetermined time ΔT (for example, 10 to 15 seconds)
During that period, the solenoid valve is closed and the high temperature / high pressure refrigerant is transferred to the evaporator 130.
May be prevented from flowing into.

Further, when the vehicle is stopped due to a signal waiting or a traffic jam, it is desirable to carry out the above-mentioned control in the inside air circulation mode in order to reduce the air conditioning load.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a pressure reducer applied to the air conditioner according to the embodiment of the present invention.

FIG. 3 is a chart showing a relationship between a refrigerant flow rate and time in the air conditioner according to the embodiment of the present invention.

[Explanation of symbols]

100 ... Compressor, 110 ... Radiator, 120 ... Pressure reducer, 1
24 ... Capillary tube (throttle means), 130 ... Evaporator, 140 ... Accumulator, 200 ... Engine (driving source), 210 ... Motor (second driving source).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F25B 1/00 304 F25B 1/00 304A 361 361G (72) Inventor Shinichi Nakamura 1-chome, Showa-cho, Kariya city, Aichi prefecture No. 1 F-term in DENSO CORPORATION Stock company (reference) 3H045 AA02 AA09 AA10 AA12 AA27 BA12 BA28 BA31 CA11 CA24 CA25 CA30 DA04 DA42 DA47 DA48

Claims (5)

[Claims] 1. A compressor (100) for sucking and compressing a refrigerant by obtaining power from a driving source (200) for traveling and a second driving source (210) different from the driving source (200), A radiator (110) for cooling the refrigerant discharged from the machine (100), a decompressor (120) for decompressing the refrigerant flowing out from the radiator (110), and a refrigerant decompressed by the decompressor (120). When the compressor (100) is driven by the second drive source (210), the flow rate of the refrigerant discharged from the compressor (100) is periodically changed. A vehicle air conditioner characterized by being changed. 2. The second drive source (210) is an electric motor, and the second drive source (210) is further provided after the drive source (200) for traveling is stopped. Evaporator (130)
The vehicle air conditioner according to claim 1, wherein the vehicle air conditioner starts to operate when the temperature reaches a predetermined temperature or higher. 3. The second drive source (210) is an electric motor, and the second drive source (210) is a predetermined one after the drive source (200) for traveling is stopped. The vehicle air conditioner according to claim 1, wherein the air conditioner starts operating when time has elapsed. 4. The decompressor (120) is a thermal expansion valve that mechanically adjusts the valve opening so that the refrigerant superheat on the outlet side of the evaporator (130) has a predetermined value. The vehicle air conditioner according to claim 2 or 3, further comprising a throttle means (124) that bypasses the pressure reducer (120) and causes a refrigerant to flow. 5. The compressor (100) is a variable displacement compressor capable of changing a discharge capacity, and further, the compressor (100) is connected to the second drive source (2).
The vehicle air conditioner according to any one of claims 1 to 4, wherein the compressor (100) has a discharge capacity smaller than a maximum discharge capacity when driven by the compressor (10). apparatus.