JPH06344767A - Air conditioner - Google Patents

Abstract

PURPOSE:To make the rotational speed of a compressor (variable speed motor) so as not to be suddenly changed at a time when an air-conditioning condition has turned to a state of being suddenly changed. CONSTITUTION:In the case where a necessary blowoff temperature is not produced by merely a mixture of inside and outside air (when a judgment of step 181 is NO), it goes forward to steps 183 and 184, whether an air-conditioning condition is a steady state or sudden change state is judged by the presence of a changeover of an operation mode and that of an object sensor (a sensor subject to data reading). When the air-conditioning condition is in a suddenly changed state (judgments of both steps 183 and 184 are YES), an inverter frequency variation Dfn is set to '0' (step 186) till the specified time has elapsed, and then rotational speed of a compressor (inverter target frequency fn) is held. On the other hand, in the case where these changeovers of the operation mode and the object sensor, the frequency variation Dfn and the target frequency fn are calculated (steps 187 and 188).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner in which a compressor of a refrigeration cycle is driven at a variable speed by a variable speed motor to control an air conditioning operation.

[0002]

2. Description of the Related Art Recently, in an air conditioner mounted on, for example, an electric vehicle, it has been considered that a compressor of a refrigeration cycle is driven at a variable speed by a variable speed motor such as an inverter in order to save power consumption and improve air conditioning performance. .
In this system, the inverter frequency of the variable speed motor is controlled so that the rotation speed of the compressor follows the control target value calculated based on the output data of various sensors according to the air-conditioning condition in the vehicle interior. .

[0003]

By the way, when the operation mode of the refrigeration cycle is switched from the heating mode to the dehumidifying and heating mode, for example, a sensor as a target of data reading for calculating a control target value (hereinafter referred to as "target sensor"). That is, there is a sensor that can switch from a sensor that detects the temperature of a heating heat source to a sensor that detects the rear temperature of an evaporator that is a dehumidification source. In this case, since the refrigerant is not supplied to the evaporator in the heating mode, the temperature at the rear side of the evaporator is room temperature (for example, around 25 ° C.) as shown in FIG. Therefore, immediately after switching from the heating mode to the dehumidifying and heating mode, the temperature after the evaporator is too high in view of the steady state (for example, 8 ° C.) in the dehumidifying and heating mode, so that the inverter frequency rapidly rises and the power consumption increases. There is a problem that the number increases rapidly. Such a problem is not limited to the above-mentioned operation mode switching, but also when the load suddenly changes (for example, when the intake mode of the inside / outside air is switched) or when the set temperature is switched, the air conditioning state suddenly changes. Occurs when

The present invention has been made in consideration of such circumstances, and an object thereof is to improve power consumption by improving a control method of a compressor (variable speed motor) when an air conditioning state suddenly changes. It is to provide an air conditioner capable of saving energy.

[0005]

In order to achieve the above object, an air conditioner of the present invention comprises a variable speed motor that drives a compressor of a refrigeration cycle at a variable speed, and the aforesaid air conditioner operates in accordance with an air conditioning operation state of the refrigeration cycle. In the one in which the rotation speed of the variable speed motor is controlled so that the rotation speed of the compressor follows the control target value, a determination means for determining whether the air conditioning state is a steady state or a sudden change state, and an air conditioning When the state is a sudden change, a sudden change time control means is provided for temporarily inhibiting the change of the rotation speed of the compressor or limiting the rotation speed of the variable speed motor to a predetermined value or less.

[0006]

When the air conditioner suddenly changes (for example, when the operation mode of the refrigeration cycle is switched or when the load is suddenly changed or the set temperature is switched), the judging means judges that
The sudden change control means operates to regulate the rotational speed of the variable speed motor so that the change in the rotational speed of the compressor is temporarily prohibited or limited to a predetermined value or less. While such an abrupt change time control is being performed, the air conditioning state gradually approaches the steady state, so when the abrupt change time control returns to normal (steady state) air conditioning control, Since the difference between the rotation speed and the control target value is considerably narrowed, sudden changes in the rotation speed can be avoided.

[0007]

【Example】

[First Embodiment] A first embodiment in which the present invention is applied to an air conditioner for an electric vehicle will be described with reference to FIGS. 1 to 12. First, a schematic configuration of the entire air conditioner will be described with reference to FIG. On the upstream side of the blower case 21, there are provided an outside air suction port 22 for sucking air (outside air) outside the vehicle compartment and two inside air suction ports 23, 24 for sucking air (inside air) inside the vehicle compartment. An inside / outside air damper 25 is provided at an intermediate portion between the inside air inlet 23 and the outside air inlet 22, and the opening degree of the inside / outside air damper 25 is adjusted by a servo motor 26 to adjust the outside air inlet 22 and the inside air. Intake port 23,2
The intake air temperature is adjusted by changing the mixing ratio of the air sucked from No. 4. The blower 2 is provided on the downstream side of the inside / outside air damper 25 and on the downstream side of the inside air suction port 24, respectively.
7 and 28 are provided, and both blowers 27 and 28 are attached to the rotation shaft of a blower motor 29. The blower motor 29 is driven by the drive circuit 30.

On the other hand, an evaporator 31 is arranged on the downstream side of the blowers 27, 28, and the downstream side of the evaporator 31 is partitioned by a partition plate 32 into two upper and lower ventilation passages 33, 34. A condenser 35 is arranged in the lower ventilation passage 34, and an upper portion of the condenser 35 is projected into the upper ventilation passage 33. This capacitor 35
A strong cooling damper 36 is disposed above the, and by driving the strong cooling damper 36 by a servo motor 37,
The air volume that bypasses the condenser 35 is variable. Further, the partition plate 32 on the downstream side of the condenser 35
A communication damper 38 is disposed in the communication port 32a provided in the drive unit 32. By driving the communication damper 38 by a servomotor 39, the amount of air passing through the communication port 32a of the partition plate 32 can be changed to a single mode. (For example, "VENT"
Mode, "FOOT" mode, etc.).

A diff outlet 40 and a vent outlet 41 are provided downstream of the upper ventilation passage 33, and a wide outlet 42 and a spot outlet 43 are provided downstream of the vent outlet 41. ing. In this case, the wide air outlet 42 is, as shown in FIG.
And an instrument panel 45 on the passenger side are formed in a laterally long shape, and a small air volume (for example, 200 m ³ / h, wind speed 3 m /
The wind of (sec) is blown out gently. On the other hand, the spot air outlet 43 is connected to the instrument panel 4
A total of four places are provided at the center part and the left and right end parts of 5, and a large air volume (for example, 400 m ³ /
h, the wind speed is 10 m / sec). The small air volume (wide air outlet 42) and the large air volume (spot air outlet 43) are switched between the spot / wide switching damper 46 provided on the outlet side of the vent air passage 41.
(See FIG. 3) is driven by the servo motor 47. Further, dampers 48 and 49 are provided on the inlet side of the vent outlet passage 41 and the differential outlet 40, respectively, and these dampers 48 and 49 serve as servo motors 50 and 49, respectively.
It is driven by 51. On the other hand, a foot outlet 52 that blows wind toward the feet of the occupant is provided on the downstream side of the lower ventilation passage 34.
Also, the damper 54 driven by the servo motor 53
Is provided. Each damper 36, 38, 46, 25
Are operated as shown in Table 1 below according to the blowing mode.

[0010]

[Table 1]

In Table 1, in the "FACE / spot" mode, the air is blown from the spot outlet 43, and in the "FACE / wide" mode, the wide outlet 4 is used.
2 blows the wind, and in the "B / L" mode, the wind blows from both the wide air outlet 42 and the foot air outlet 52,
In the "FOOT" mode, the air is blown from the foot outlet 52 and the differential outlet 40 at a ratio of 80:20, and the "FOO
In the "T / DEF" mode, the air is blown from the foot outlet 52 and the differential outlet 40 at a ratio of 50:50, and the "DE
In the "F" mode, the dampers 46, 48, 49 and 54 are switched so that the wind is blown from the differential air outlet 40. The opening degree of the inside / outside air damper 25 is linearly controlled as described later.

On the other hand, the evaporator 31 and the condenser 35 described above are components of the refrigeration cycle 55 which also serves as a heat pump. This refrigeration cycle 55 includes a compressor 56, a four-way switching valve 57, an outdoor heat exchanger 58, check valves 59 and 60, a capillary 61, solenoid valves 62 and 63,
64, the pressure reducing valve 65, the accumulator 90, the evaporator 31, and the condenser 35 are connected by piping. The electromagnetic valves 62, 63, 64 and the four-way switching valve 57 are switched as shown in Table 2 below according to the operation mode of the refrigeration cycle 55.

[0013]

[Table 2]

As is apparent from Table 2, in the cooling mode, the four-way switching valve 57 is switched to the position (ON position) shown by the dotted line in FIG.
The refrigerant discharged from a is a check valve 59 → the outdoor heat exchanger 5
8 → Capillary 61 → Evaporator 31 → Accumulator 90 → Suction port 56b of the compressor 56. As a result, the discharge port 56a of the compressor 56
The high temperature gas refrigerant discharged from the heat exchanger 58 dissipates heat and liquefies in the outdoor heat exchanger 58, and the liquid refrigerant evaporates in the evaporator 31 to cool the wind passing through the evaporator 31. On the other hand, in the heating mode, the four-way switching valve 57 is switched to the position (off position) shown by the solid line in FIG. 3, and the refrigerant discharged from the discharge port 56a of the compressor 56 is changed from the condenser 35 to the pressure reducing valve 65 to the check valve. 60 → outdoor heat exchanger 58
→ solenoid valve 62 → accumulator 90 → compressor 56
Circulates in the path of the suction port 56b. As a result, the high temperature gas refrigerant discharged from the discharge port 56a of the compressor 56 radiates heat and liquefies in the condenser 35, and the heat radiation warms the wind passing through the condenser 35. In the defrosting mode, the four-way switching valve 57 is at the position shown by the solid line in FIG.
The solenoid valve 63 is opened, and the discharge port 56 of the compressor 56 is opened.
The high-temperature gas refrigerant discharged from a is also supplied to the outdoor heat exchanger 58 via the condenser 35 and the electromagnetic valve 63 to remove the frost adhering to the surface of the outdoor heat exchanger 58.

Further, in the dehumidifying H mode, the four-way switching valve 57
Is the position shown by the solid line in FIG. 3, the solenoid valve 63 is closed and the solenoid valve 6
4 is opened, part of the liquid refrigerant supplied to the outdoor heat exchanger 58 is also supplied to the evaporator 31, and the evaporator 31 is dehumidified by the weaker cooling action. Further, in the dehumidification C mode, the four-way switching valve 57 is at the position shown by the solid line in FIG. 3, the solenoid valve 63 is opened, and the outdoor heat exchanger 58 also functions as a condenser together with the condenser 35. The refrigerant liquefied in both the outdoor heat exchanger 58 is supplied to the evaporator 31, and the evaporator 3
It is dehumidified by the strong cooling action of 1.

The outdoor heat exchanger 58 is provided with an outdoor fan 89 for forced cooling, and the fan motor 89a of the outdoor fan 89 has a refrigeration cycle 5 as shown in FIG.
High-speed rotation “Hi”, low-speed rotation “Lo”, stop “OF” according to the operation mode of 5 and output data of various sensors described later.
For example, in the cooling mode, the outside air temperature Tam detected by the outside air temperature sensor 78 becomes “Hi” at 25 ° C. or higher and becomes “Lo” at 22 ° C. or lower. In heating mode, outside temperature Tam
Becomes "Hi" below 13 ℃, and "Lo" above 16 ℃
Becomes In the dehumidification H mode, when the temperature difference [TAO-Tc] between the blow-out temperature TAO described later and the wind temperature immediately after passing through the condenser 35 (hereinafter referred to as "condenser rear side temperature") Tc is 0 ° C or less, it becomes "OFF", and 2 It becomes “Hi” above the temperature of 0 ° C. and becomes “Lo” in the range of 1 ° C. → 2 ° C. and 1 ° C. → 0 ° C.
In the dehumidification C mode, Hi> Lo due to the refrigerant discharge pressure Pr of the compressor 56 detected by the refrigerant discharge pressure sensor 88 and the condenser rear side temperatures Tc and TAO-Tc.
It is determined by the priority order of> OFF. For example, if the refrigerant discharge pressure Pr is 19 kgf / cm @ 2 G or more, then Tc, T
Whatever the value of AO-Tc, it is always "Hi". Similarly, if TAO-Tc is -2 ° C or lower,
Even if the refrigerant discharge pressure Pr is lower than 19 kg / cm @ 2 G, it is always "Hi".

On the other hand, the compressor 5 of the refrigeration cycle 55
The motor 66 that drives 6 is a variable speed motor whose rotation speed is controlled by an inverter 67. This inverter 67, servo motors 26, 37, 39, 4
7, 50, 51, 53, the fan motor 89 a of the outdoor fan 89, and the drive circuit 30 of the blower motor 29 are controlled by an electronic control unit (hereinafter referred to as “ECU”) 68. The ECU 68 mainly includes a microcomputer, a CPU 69, a RAM 70 for temporarily storing various data, a ROM 71 in which the control programs shown in FIGS. 1 and 2 are stored, and an A for converting input data into digital values. / D converter 72, I / O section 73, number M
A crystal oscillator 74 for generating a reference signal of Hz is provided, and power is supplied from a battery 75 via an ignition switch 76.

The ECU 68 includes an inside air temperature sensor 77 for detecting the inside air temperature Tr, an outside air temperature sensor 78 for detecting the outside air temperature Tam, a solar radiation sensor 79 for detecting the amount of solar radiation Ts entering the passenger compartment, and a cold air temperature immediately after passing through the evaporator 31. (Hereinafter, referred to as "evaporator rear temperature") Te evaporator rear temperature sensor 80, condenser rear temperature sensor 81 detecting condenser rear temperature Tc, refrigerant discharge pressure sensor detecting refrigerant discharge pressure Pr of the compressor 56 88, an output signal from the temperature sensation setter 82 or the like for the occupant to manually set the set temperature sensation Sset to be the control target is read via the A / D converter 72.

The warmth setting device 82 described above is provided with the cool key 8
2a and a warming key 82b are provided, and as shown in FIG.
It is provided on an air conditioner control panel 83 arranged at the center of the instrument panel 45. As shown in FIG. 5, the air conditioner control panel 83 is provided with a temperature sensation display section 84 in which a plurality of light emitting elements 84n are arranged in a row above the temperature sensation setter 82. The warmth display section 84 includes a cool key 82a and a warm key 82b.
The set temperature sensation Sset input by is displayed. This set temperature sensation Sset is an index indicating how cool or warm the temperature is based on the average temperature of 25 ° C. [see FIG. 7 (a)], and before operating the keys 82a and 82b. In the state, the light emitting element 84n in the center of the temperature sensation display section 84 is lit, and each time the cool key 82a is pressed, the set temperature sensation Sset is decreased by one rank and the lighting position is shifted to the left one by one, Each time the warming key 82b is pressed, the set temperature sensation Sset is increased by one rank and the lighting position is shifted to the right one by one. In addition, the air conditioner control panel 83 is provided with a system on / off switch 85, a rear defogger switch 86, and a front defroster switch 87.

On the other hand, the ECU 68 controls the overall air conditioning operation by executing the main control program shown in FIG. Further, the ECU 68 functions as a judging means for judging whether the air conditioning state is a steady state or a sudden change state by executing the inverter frequency control routine of FIG. It also functions as a sudden change control means for restricting the rotation speed of the variable speed motor 66 so as to temporarily prohibit the change of the rotation speed of 56. In the first embodiment, whether or not the operation mode is switched and the target sensor is switched is used as a criterion for determining whether or not the air-conditioning state is in a sudden change state.

The control contents of the ECU 68 will be described below with reference to the flowcharts of FIGS. First,
In step 100, after initialization processing for initializing counters and flags used for the subsequent calculation processing is executed, the process proceeds to step 110, and the set temperature sensation Sset input by the operation of the temperature sensation setter 82 is read. At the same time, the inside air temperature Tr, the outside air temperature Ta detected by the inside air temperature sensor 77, the outside air temperature sensor 78, the solar radiation sensor 79, the evaporator rear side temperature sensor 80, and the condenser rear side temperature sensor 81.
Each data of m, solar radiation Ts, evaporator rear temperature Te and condenser rear temperature Tc is read.

Next, at step 120, the set temperature Tset is obtained from the set temperature sensation Sset, the outside air temperature Tam and the solar radiation amount Ts by the following equation (1). Tset = f (Sset, Tam, Ts) = Tset '+ ΔTam + ΔTs (1) where Tset' = 25 + 0.4Sset ..
See (a) ΔTam = (10−Tam) / 20 …… See FIG. 7 (b) ΔTs = −Ts / 1000 …… See FIG. 7 (c)

After the set temperature Tset is calculated as described above, the routine proceeds to step 130, where the set temperature Tset in the vehicle compartment is set.
The heat quantity QAO required to maintain the set value is calculated by the following equation (2). QAO = K1 * Tset-K2 * Tr-K3 * Tam-K4 * Ts + C (2) where K1, K2, K3 and K4 are coefficients and C is a constant. This equation (2) is apparently the same as the conventional one, but each coefficient K
1, K2, K3, K4 and the constant C are set to values considerably larger than before (for example, K1 = 170, K2 = 170, K3 =
35, K4 = 130, C = 1150), and the degree of freedom of the blown air volume VAO and the blown air temperature TAO described later is large.

After calculating the required heat quantity QAO by the above equation (2), the routine proceeds to step 140, and it is judged as follows whether the air-conditioning state at that time is a steady state or a transient state. First, a temperature difference | Tset-Tr | between the set temperature Tset and the inside air temperature Tr is calculated, and this | Tset-Tr |
Is less than or equal to a predetermined value δ (for example, δ = 3 ° C.), and if | Tset −Tr | ≦ δ, it is determined to be a steady state.
If | Tset-Tr |> δ, it is determined that the state is a transient state.

In the steady state, the routine proceeds to step 141, where the air volume VB is obtained from the air volume characteristics with respect to the required heat quantity QAO in the steady state shown in FIG. 8, and this air volume VB is set as the blowout air volume VAO. Further, the outlet temperature TAO is obtained from the temperature characteristic with respect to the required heat quantity QAO in the steady state shown in FIG. 8 (step 142). Note that, in FIG. 8, the air flow rate / temperature characteristic of the present embodiment is shown by a solid line, and the air flow rate / temperature characteristic of the conventional automatic air conditioner is shown by a dashed line. As is apparent from FIG. 8, the air flow rate characteristic of this embodiment is C of the refrigeration cycle 55.
Aiming to improve OP, air volume V in the area where required heat quantity QAO is small
Although B is increased more than before, this increase in air volume is set so that the occupants do not feel uncomfortable with the wind. By adopting such an air flow rate characteristic, the temperature characteristic of the present embodiment is, for example, 5 ° C. more than before when the outlet temperature TAO is cooling.
The temperature is set to be high, and when heated, the temperature is set to be 15 ° C. lower than that of the conventional case.

On the other hand, if it is determined in step 140 that the engine is in a transient state, the flow proceeds to step 143 to calculate the blown air volume VAO by the following equation (3). VAO = VB + ΔV (3) Here, VB is the required heat quantity Q in the steady state shown in FIG.
It is calculated from the air flow rate characteristics for AO. Further, ΔV is a corrected air volume, which is obtained from the corrected air volume characteristic with respect to Tr-Tset shown in FIG. In this embodiment, the corrected air flow rate ΔV is set to be “0” during heating.
The reason for this is that if the blow-out air volume VAO is significantly increased during heating, the blow-out temperature TAO will drop too much, and the warmth felt by the blown wind will be rather reduced (however, during heating, as will be described later). May be set so that ΔV> 0 within a range that does not give an occupant a discomfort).

After the blowout air volume VAO is calculated by the above equation (3), the routine proceeds to step 144, where the blowout temperature T during the transition is set.
AO is calculated by the following equation (4). TAO = QAO / (Cp.γ.VAO) + Tr = 3.57 × QAO / VAO + Tr (4) [Cp: specific heat of air, γ: specific gravity of air (25 ° C)]

An example of the operation by such control is shown in FIG. 10, and FIG. 11 shows the blowing air volume VAO and the COP of the refrigeration cycle 55.
Shows the relationship with. As is apparent from FIGS. 10 and 11, the blown-out air volume VAO is corrected to the corrected air volume ΔV during the transition.
The COP of the refrigerating cycle 55 is improved by increasing the air flow rate VAO in a steady state, and the occupant does not feel uncomfortable due to the air flow to create a comfortable air-conditioning environment. Moreover, the required heat quantity QAO is calculated in advance in both transient and steady-state conditions, and the required heat quantity QA
Since the blow-off air volume VAO and the blow-out temperature TAO are determined so as to generate AO, cooling and heating do not become excessive, and power saving can be achieved in combination with the above-described COP improvement at the time of transition.

On the other hand, when the process of step 142 or step 144 described above is completed, the process proceeds to step 150, and the temperature of the air taken in from the inside air intake ports 23 and 24 and the outside air intake port 22 (hereinafter referred to as "intake air temperature"). Inside and outside air damper 2 in the direction to reduce the temperature difference between Tin and the outlet temperature TAO.
The opening degree of 5 is calculated as follows. Here, the intake air temperature Tin is obtained by the following equation (5). Tin = α · Tam + (1−α) · Tr (5) (α: mixing ratio of outside air) Using this relationship, first, the outlet temperature TAO and the intake air temperature Tin at the time of complete inside air (α = 0) The absolute value Tdi of the temperature difference from (= Tr) is calculated by the following equation (6). Tdi = | TAO-Tr | (6) Next, the blow-out temperature T at the maximum intake of outside air (α is maximum)
The absolute value Tdo of the temperature difference between AO and the intake air temperature Tin is given in (7) below.
Calculate by formula. Tdo = | TAO- {α · Tam + (1-α) · Tr} | (7) After that, Tdi and Tdo are compared to determine the magnitude, and T
If di ≦ Tdo, the inside air mode (α = 0) is set, and the outside air suction port 22 is fully closed by the inside / outside air damper 25.

On the other hand, if Tdi> Tdo, the outside air mode is set, and the mixing ratio x of the outside air is calculated by the following equation (8). x = (TAO-Tr) / (Tam-Tr) (8) x calculated by the equation (8) is a value (αmax) at the maximum intake of the outside air and a value (α) at the inside air mode. = 0)
When 0 ≦ x ≦ αmax, the x is set as a target outside air mixing ratio, and the opening degree of the inside / outside air damper 25 is linear (linear) so as to realize the target outside air mixing ratio x. It becomes the combination mode of inside and outside air that can be changed to.

By performing such control, the opening degree of the inside / outside air damper 25 is automatically adjusted so as to reduce the difference between the blowout temperature TAO and the intake air temperature Tin, and the amount of heat given to the sucked air (the required amount of heat) QAO) is small and further power saving is possible.

In step 150 described above, the inside / outside air damper 2
When the opening degree of 5 is calculated, the process proceeds to step 160,
Each damper 3 is based on the blowing temperature TAO and the blowing air volume VAO.
6, 38, 46, 48, 49, 54 are determined, and the blowout mode is set to "FACE (spot)", "FACE (wide)", "B / L", "FOOT", "FOOT / D".
Either EF "or" DEF "is determined. Details of this blowing mode are shown in Table 1 above.

After determining the blowing mode in this way,
In step 170, the operation mode of the refrigeration cycle 55 is determined as follows: cooling, heating, dehumidifying heating, dehumidifying cooling. First, the intake air temperature Tin is calculated by the above equation (5). In this case, the intake air temperature Tin is calculated using the x calculated in step 150 described above as the mixing ratio α of the outside air. Next, the temperature difference TM between the outlet temperature TAO and the intake air temperature Tin is calculated by the following (9)
Calculate by formula.

TM = TAO−Tin (9) Then, when TM ≧≧ θ (eg θ = 2 ° C.), the heating mode is set, and when TM ≦ −θ, the cooling mode is set, −
When θ <TM <+ θ, the compressor 56 of the refrigeration cycle 55 is stopped. Further, when the front defroster switch 87 is turned on, the dehumidifying mode is set, and whether to perform dehumidifying heating or dehumidifying cooling is determined by the above-described determination.

After determining the operation mode of the refrigeration cycle 55 in this way, the routine proceeds to step 180, where the inverter frequency control routine (see FIG. 2) for determining the target frequency of the inverter 67 is executed as follows. First,
In step 181, it is determined whether or not the blowout temperature TAO required to maintain the vehicle interior at the set temperature Tset can be created only by mixing the inside air and the outside air. As the determination method, the mixing ratio x of the outside air calculated in step 150 is used to determine whether 0 ≦ x ≦ αmax. That is, when 0≤x≤αmax, the required outlet temperature TAO is within the range between the outside air temperature Tam and the inside air temperature Tr (Tr≤T
Since AO ≤ Tam or Tam ≤ TAO ≤ Tr), the required outlet temperature TAO can be created only by mixing the inside and outside air.
Therefore, in this case, the determination in step 181 is "YE
S ”, the process proceeds to step 182 and the inverter 67
The (variable speed motor 66) is stopped and the compressor 56 is stopped.

On the other hand, if "NO" in step 181,
That is, in the case of x <0 or x> αmax, the required outlet temperature TAO is not within the range between the outside air temperature Tam and the inside air temperature Tr, so that the required outlet temperature TAO cannot be created only by mixing the inside air and the outside air. Therefore, in this case, the process proceeds to step 183 to control the operation of the compressor 56. In this embodiment, by this step 183 and the next step 184, it is determined whether the air-conditioning state is a steady state or a sudden change state, whether or not the operation mode is switched, and the target sensor (sensor for reading data) is switched. It is judged as follows depending on the presence or absence of

First, in step 183, it is determined whether the operation mode has been switched. Here, when the operation mode of the refrigeration cycle 55 determined in step 170 described above is different from the previous (one time before) determination (for example, heating → cooling, heating → dehumidification heating, etc.), the determination in step 183 is made. The result is “YES”, and the routine proceeds to step 184. In this step 184, it is determined whether or not the target sensor has been switched. For example, the target sensor changes from the condenser rear side temperature sensor 81 (condenser rear side temperature Tc) to the evaporator rear side temperature sensor 80 when switching from heating to dehumidifying heating.
(When the temperature after the evaporator Te is changed),
In the opposite case, or when the evaporator rear temperature sensor 80 (evaporator rear temperature Te) is switched to the condenser rear temperature sensor 81 (condenser rear temperature Tc) with the switching from cooling to heating. Or vice versa, the determination in step 184 above is “YE
S ”, and the process proceeds to step 185.

In this step 185, it is judged whether a predetermined time (for example, 3 minutes) has elapsed from the time of switching the target sensor by the timer operation. If "NO", the process proceeds to step 186 and the inverter 67 is operated. Frequency change amount Df
The n is set to "0", the frequency of the inverter 67 is maintained as it is (step 188), and the frequency signal is output to the inverter 67 (step 189). As a result, the change in the rotation speed of the variable speed motor 66 (compressor 56) is prohibited and the current rotation speed is maintained (hold).
To do. The holding of the rotation speed is continued until a predetermined time (for example, 3 minutes) elapses from the switching of the target sensor (step 185). During this time, the air-conditioning state gradually approaches the steady state, so by the time the timekeeping operation for the above-mentioned predetermined time ends (time-up), the rotation speed of the variable speed motor 66 (frequency of the inverter 67) and the control target value. The difference between and is narrowed considerably, and sudden changes in rotation speed can be avoided.
Then, when the above predetermined time has elapsed and the determination in step 185 is "YES", the process proceeds to step 187 and the frequency change amount Dfn of the inverter 67 is calculated.

Frequency change amount Dfn of the inverter 67
Is calculated when the air-conditioning state is a steady state, that is, when the operation mode or the target sensor is not switched (when either of steps 183 and 184 is “NO”), or the time after the switching. When it is up (when step 185 is "YES"), it is performed as follows.

In the cooling mode, the frequency of the inverter 67 is feedback-controlled by PI control or fuzzy control for the evaporator rear temperature Te detected by the evaporator rear temperature sensor 80, and in the heating mode, after the condenser. Feedback control is performed by PI control or fuzzy control for the capacitor rear temperature Tc detected by the side temperature sensor 81.

For example, when performing PI control, first,
The temperature deviation En is calculated by the following equation (10). En = TAOn-Tn (10) Here, the subscript n of each variable indicates that it is the nth sample value, TAOn indicates the outlet temperature obtained in steps 142 and 144, and Tn indicates the cooling mode. Alternatively, in the dehumidification mode, it shows the evaporator rear temperature Te, and in the heating mode it shows the condenser rear temperature Tc.

Next, the frequency change amount D of the inverter 67
fn is calculated by the following equation (11). Dfn = Kp {(En-En-1) + t / TI.En} (11) where Kp is the proportional gain, t is the sample time, and TI
Is the integration time.

Thereafter, the process proceeds to step 188, and the frequency change amount Dfn obtained in step 186 or 187 described above.
From this, the target frequency fn of the inverter 67 is calculated by the following equation (12). fn = fn-1 + Dfn (12) After that, the routine proceeds to step 189, where the target frequency fn is output to the inverter 67 to control the rotation speed of the compressor 56.

The various control data determined as described above are output to each device (step 190), and thereafter, the process returns to step 110 described above and the processing is repeated to control the air conditioning operation. At this time, steps 141 and 1
The blower voltage applied to the blower motor 29 in order to realize the blown air volume VAO obtained in step 43 is determined according to the blowout mode by the voltage characteristic of FIG.

According to the first embodiment described above, when the air conditioning state is in a sudden change state (within a predetermined time after the operation mode is switched and the target sensor is switched), the rotation speed of the compressor 56 is temporarily changed. Since the rotation speed of the variable speed motor 66 (the target frequency of the inverter 67) is held so as to be prohibited, the air-conditioning state gradually approaches the steady state during that time. When returning to the normal (steady state) air conditioning control, the difference between the rotation speed of the variable speed motor 66 and the control target value is considerably narrowed, and a sudden change in the rotation speed is avoided.
Power consumption will be reduced.

[Second Embodiment] In the first embodiment, when the air-conditioning state is in a sudden change, the change in the rotation speed of the compressor 56 is temporarily prohibited (the target frequency of the inverter 67 is held). Alternatively, the change of the target frequency of the inverter 67 may be limited (limiter) so that the change of the rotation speed of the compressor 56 is limited to a predetermined value or less. A second embodiment embodying this is shown in FIG.
In the following, parts different from the first embodiment will be described.

When it is determined that the air-conditioning state is a sudden change, that is, when the operation mode is switched and the target sensor is switched (the determinations at steps 183 and 184 are both "YE").
S ”), the process proceeds to step 200, and the frequency change amount Dfn of the inverter 67 is changed as in step 187.
Is calculated by the above equations (10) and (11). After that, the process proceeds to step 201, and the calculated frequency change amount Df
Since a limiter is applied to n, | Dfn | ≧ a (for example, a
= 100 Hz), and if “YES”, the process proceeds to step 202. In this step 202, if Dfn obtained in step 200 is a positive value,
If Dfn = a is set and Dfn is a negative value, Dfn
= -A. After that, the process proceeds to step 188, and the target frequency fn of the inverter 67 is calculated using the value of Dfn.
Is calculated by the above-mentioned equation (12).

On the other hand, when the determination in step 201 is "NO" (when -a <Dfn <a), the difference between the rotation speed of the variable speed motor 66 (frequency of the inverter 67) and the control target value is determined. Therefore, the frequency change amount Dfn calculated in step 200 is used as it is, and the inverter 6
The target frequency fn of 7 is calculated (step 188).

In the second embodiment, a limiter is applied to the frequency change amount Dfn of the inverter 67 when it is determined that the air-conditioning state is a sudden change state. Therefore, as in the first embodiment, the variable speed motor 66 is used. A sudden change in the rotation speed of the (compressor 56) is avoided, and power consumption is reduced.

[Third Embodiment] In the first embodiment, whether or not the operation mode is switched and the target sensor is switched is adopted as a criterion for determining whether or not the air-conditioning state is a sudden change. However, the present invention is not limited to this. Instead, for example, when the load suddenly changes (for example, when the intake mode of the inside / outside air is switched), the set temperature sensation Sset
It is possible to adopt various conditions that cause a sudden change in the target frequency fn of the inverter 67, such as when the (or set temperature) is switched.

Hereinafter, a third embodiment in which the sudden change control is performed when the intake mode of the inside and outside air is switched is shown in FIG.
4 will be described (here, mainly the parts different from the first embodiment will be described). When the required outlet temperature TAO cannot be created only by mixing the inside and outside air (step 181)
In the case of “NO”), the process proceeds to step 210, and it is determined whether the inside / outside air damper 25 has been switched. Here, if “YES” is determined, the process proceeds to step 185, and the frequency change amount D of the inverter 67 is maintained until a predetermined time (for example, 3 minutes) has elapsed from the switching of the inside / outside air damper 25.
fn is set to "0" (steps 185 and 186). On the other hand, if the inside / outside air damper 25 has not been switched, it is determined to be "NO" in step 210, the process proceeds to step 187, and the frequency change amount Dfn of the inverter 67 is calculated.

In this case as well, it goes without saying that a limiter may be applied to the frequency change amount Dfn of the inverter 67 as in the second embodiment.

[Fourth Embodiment] Step 15 of the first embodiment
The calculation method of the opening degree of the inside / outside air damper 25 at 0 may be changed as follows. First, the outlet temperature TAO and the intake air temperature T
The absolute value Toα of the temperature difference from in is calculated by the following equation (13). Toα = | TAO−Tin | = | TAO− {α · Tam + (1-α) · Tr} | (13) where α is the mixing ratio of outside air, and this α is 0 ≦ α ≦
By varying within the range of αmax (αmax is the value of α at the time of maximum intake of outside air), α that minimizes the absolute value Toα of the temperature difference between the outlet temperature TAO and the intake temperature Tin is obtained, and this α is mixed with the target outside air. As a ratio, the opening degree of the inside / outside air damper 25 is changed linearly.

[Fifth Embodiment] In the first embodiment, the temperature sensation Sset is set by the manual operation of the temperature sensation setter 82, and the set temperature Tset is calculated from the set temperature sensation Sset, the outside air temperature Tam and the solar radiation amount Ts. However, the temperature setting device 82 is replaced with a set temperature switch (not shown) for manually setting the set temperature Tset, and the set temperature Tset is set by manually operating the set temperature switch. It may be done. In this case, step 120 of FIG. 1 becomes unnecessary.

[Other Embodiments] In the case of the first embodiment, during cooling, during the transition, the blown air volume VAO is increased by the corrected air volume ΔV from the steady state to improve the COP of the refrigeration cycle 55. However, when heating, the correction air volume Δ
Since V is set to "0" (see FIG. 9), the air volume characteristic is the same even in the transient state as in the steady state. The reason for this is that if the amount of blown air VAO is greatly increased during heating, the blown air temperature TAO will drop too much, and the warmth felt by the blown wind will be rather reduced.

However, even during heating, the corrected air flow rate ΔV
May be set to ΔV> 0 to increase the blown air volume VAO during a transition to such an extent that the passenger does not feel uncomfortable. In this case, the blowout temperature TAO decreases in accordance with the increase amount of the blown air amount VAO, but the amount of heat given to the vehicle interior can secure the required amount of heat by the increase of the blown air amount, so that the heating capacity is not lowered and the heating capacity during heating is not increased. Refrigeration cycle 55 even during transition
COP can be improved.

In the first embodiment, the present invention is applied to an air conditioner for an electric vehicle, but the present invention is applied to various air conditioners such as an air conditioner for an engine-driven automobile and a house air conditioner. Needless to say, it is okay. In the case of an engine-driven automobile air conditioner, a heat core in which engine cooling water circulates may be used as a heat source during heating, and in a general air conditioner, an electric heater is used as a heat source during heating. Is also good.

In the first embodiment, the wind is strongly blown from the spot outlet 43 when the air volume is large, and the air is gently blown from the wide air outlet 42 when the air volume is small. The air may be blown out from both the air outlets 42 and 43 at the same time. Of course, a configuration without spot / wide switching may be adopted, and in this case, the spot / wide switching damper 46 becomes unnecessary.

Further, the temperature sensation setter 82 is not limited to the key input type, but may be constituted by using a dial switch, for example. In addition, it goes without saying that the present invention can be implemented with various modifications such as appropriate modification of the configuration related to air blowing and the configuration of the warmth display unit 84.

[0060]

As is apparent from the above description, according to the present invention, when the air-conditioning state suddenly changes, the change of the rotation speed of the compressor is temporarily prohibited or limited to a predetermined value or less. Since the rotation speed of the variable speed motor is regulated, the speed of the variable speed motor (compressor) can be controlled after waiting for the difference between the rotation speed of the variable speed motor and the control target value to decrease. You can avoid sudden changes and save power consumption.

[Brief description of drawings]

FIG. 1 is a flowchart showing a main control program showing a first embodiment of the present invention.

FIG. 2 is a flowchart showing an inverter frequency control routine.

FIG. 3 is a schematic configuration diagram of the entire air conditioner.

FIG. 4 is a front view of an instrument panel portion of an automobile.

[Figure 5] Front view of the air conditioner control panel

FIG. 6 is a diagram showing a relationship between a refrigeration cycle operation mode and an outdoor fan operation mode.

7A is a diagram showing a relationship between a set temperature sensation Sset and Tset ', FIG. 7B is a diagram showing a relationship between outside air temperature Tam and ΔTam, and FIG. 7C is a relationship between solar radiation amount Ts and ΔTs. Showing

FIG. 8 is a diagram showing the air volume and temperature characteristics in a steady state.

FIG. 9 is a diagram showing a relationship between Tr −Tset and a corrected air volume ΔV.

FIG. 10 is a diagram illustrating an operation example during a transition.

FIG. 11 is a diagram showing the relationship between the blown air volume VAO, the COP, and the temperature difference ΔT between the intake and the blown air.

FIG. 12 is a diagram showing the relationship between blown air volume VAO and blower voltage.

FIG. 13 is a flowchart showing an inverter frequency control routine in the second embodiment of the present invention.

FIG. 14 is a flowchart showing an inverter frequency control routine in the third embodiment of the present invention.

FIG. 15 is a diagram showing transient changes in power consumption, inverter frequency, and evaporator rear temperature when switching operation modes.

[Explanation of symbols]

22 ... Outside air inlet, 23, 24 ... Inside air inlet, 25 ... Inside / outside air damper, 31 ... Evaporator, 35 ... Condenser,
40 ... Differential air outlet, 42 ... Wide air outlet, 43 ... Spot air outlet, 46 ... Spot / wide switching damper, 52 ...
Foot outlet, 55 ... Refrigeration cycle, 56 ... Compressor, 57 ... Four-way switching valve, 58 ... Outdoor heat exchanger, 61 ... Capillary, 62-64 ... Solenoid valve, 65 ... Pressure reducing valve, 66 ...
Variable speed motor, 67 ... Inverter, 68 ... ECU (judgment means, sudden change control means), 77 ... Inside air temperature sensor, 78
... outside air temperature sensor, 79 ... solar radiation sensor, 80 ... evaporator rear temperature sensor, 81 ... condenser rear temperature sensor, 82 ... warm feeling setting device, 82a ... cooling key, 82b ...
Warming key, 84 ... Warm-feeling display section, 88 ... Refrigerant pressure sensor, 89 ... Outdoor fan.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Ito 1-1, Showa-cho, Kariya city, Aichi Nihon Denso Co., Ltd. (72) Inventor Katsuhiko Samukawa 1-1-chome, Showa-cho, Kariya city, Aichi Prefecture Within the corporation

Claims (1)

[Claims] 1. A variable speed motor that drives a compressor of a refrigeration cycle at a variable speed, and the rotation of the variable speed motor is controlled so that the rotation speed of the compressor follows a control target value in accordance with an air conditioning operation state of the refrigeration cycle. In an air conditioner with controlled speed, a judgment means to judge whether the air conditioning state is a steady state or a sudden change state, and temporarily prohibit the change of the rotation speed of the compressor when the air conditioning state is a sudden change state. Alternatively, the air conditioner is provided with a sudden change time control means for restricting the rotation speed of the variable speed motor so as to limit it to a predetermined value or less.