JP4013717B2 - Air conditioner for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air conditioner for a vehicle, and is applied to an air conditioner for an electric vehicle using a fuel cell or an electric vehicle such as a so-called hybrid vehicle that travels in combination with an internal combustion engine (engine) and an electric motor. It is valid.
[0002]
[Prior art]
Because the waste heat for electric vehicles is less than that of a vehicle that runs only with an engine, the conventional vehicle air conditioner uses a high-pressure refrigerant in a vapor compression refrigeration machine or a heater that uses combustion gas from the combustion chamber as a heat source. The air blown out is heated (see, for example, Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-20458
[0004]
[Problems to be solved by the invention]
By the way, in a vehicle air conditioner using a heat source other than engine waste heat as a heat source, the entire amount of air blown into the room is usually heated by the air that has passed through the heater, that is, the heater. Since the heating capacity of the heater is controlled so that the temperature of the air after the air reaches the target blown air temperature, the air passing through the heater has a substantially uniform temperature distribution.
[0005]
For this reason, in the bi-level blowing mode in which air is blown upward and downward in the passenger compartment, air having substantially the same temperature is blown upward and downward, giving the passenger a good feeling of air conditioning. It is difficult.
[0006]
In general, it is said that if the temperature of the air blown upward is lower than the temperature of the air blown downward, a good air conditioning feeling can be given.
[0007]
In view of the above points, the present invention firstly provides a new vehicle air conditioner that is different from the conventional one, and secondly, in the bi-level blowing mode, the temperature of the air blown upward and the lower side thereof. The purpose is to make the temperature of the air blown out differently.
[0008]
[Means for Solving the Problems]
  In order to achieve the above object, according to the present invention, in the first aspect of the present invention, a foot blowing mode that blows air mainly to the lower side of the vehicle interior, and a face blowing mode that mainly blows air to the upper side of the vehicle interior. And a bi-level blowing mode for blowing air to the upper side and the lower side of the passenger compartment,carA vehicle air conditioner that harmonizes the air blown into the room,
  carAn air conditioning casing (80) constituting an air passage through which air blown into the room flows;
  It arrange | positions in an air conditioning casing (80) and heats the air which flows through the inside of an air conditioning casing (80).At the same time, the heating capacity can be controlledA heater (32);
  It is provided in the air conditioning casing (80) and adjusts the air volume ratio between the amount of air that flows around the heater (32) and flows downstream and the temperature of the air heated by the heater (32) and flows downstream. Air volume ratio adjusting means (81);
  A foot outlet that opens to a portion of the air conditioning casing (80) downstream of the heater (32) on the side where the warm air that has passed through the heater (32) flows and blows air downward in the passenger compartment. ,
  Of the downstream part of the heater (32) in the air-conditioning casing (80), a face outlet that opens to a part on the side through which the cold air that bypasses the heater (32) flows and blows air upward in the vehicle interior,
  A blowing mode switching device (84) that opens and closes the foot blowing port and the face blowing port to switch the foot blowing mode, the face blowing mode, and the bi-level blowing mode;
  Heating capacity control means (90) for controlling the heating capacity of the heater (32);
  The air volume ratio determining means (S201) which determines the air volume ratio of the air volume ratio adjusting means (81) so that the air volume bypassing the heater (32) increases as the heating capacity of the heater (32) increases., S202, S204, S205)
  In the air conditioning casing (80), the opening (SW) of the air volume ratio adjusting means (81) is 0% when the total amount of air flowing in the air conditioning casing (80) flows around the heater (32). When the opening degree (SW) of the air volume ratio adjusting means (81) is 100% in a state where the total amount of air flowing through the heater (32) passes through the heater (32), the air in the air conditioning casing (80) is 32) When the bi-level blowing mode is selected during heating to be heated, the opening degree (SW) of the air volume ratio adjusting means (81) is less than 100% by the air volume ratio determining means (S201, S202, S204, S205), Over 0%,
  In the bi-level blowing mode, hot air that has passed through the heater (32) and cold air that bypasses the heater (32) are generated, and the temperature of the air blown downward is higher than the temperature of the air blown upward. And
  Furthermore, the heating capacity control means (90)
  When the foot blowing mode and the face blowing mode are selected during heating, the air temperature immediately after passing through the heater (32) becomes the temperature (Tgco) corresponding to the target temperature (TAO) of the air blown into the passenger compartment. First control means (S223) for controlling the heating capacity of the heater (32),
  During heatingWhen the bi-level blow mode is selected, the air temperature immediately after passing through the heater (32) is higher than the target temperature (TAO) of the air blown into the passenger compartment.And the temperature given by the first control means (S223)The heating capacity of the heater (32) is controlled so that the temperature becomes high.Second control means (S222).It is characterized by that.
[0009]
  As a result, the air volume ratio of the air volume ratio adjusting means (81) is less than 100% and more than 0% so that the air volume bypassing the heater (32) increases, so the air that has passed through the heater (32). Is the temperature of the air blown upward in the bi-level blowing mode when hot air heated by the heater (32) and cold air bypassing the heater (32) are generated.thanThe temperature of the air blown out downwardIncreasebe able to.
[0010]
  According to a second aspect of the present invention, in the vehicle air conditioner according to the first aspect, the first control means (S223) is configured such that when the foot blowing mode and the face blowing mode are selected during heating, the heater (32 ), The heating capacity of the heater (32) is controlled so that the air temperature immediately after passing through () becomes the same temperature (Tgco) as the target temperature (TAO) of the air blown into the passenger compartment.
  Claim3In the invention described inThe vehicle air conditioner according to claim 1 or 2,The heating capacity control means (90)During heatingIf the target temperature (TAO) is equal to or higher than the predetermined temperature when the bi-level blowing mode is selected, the temperature difference between the air temperature immediately after passing through the heater (32) and the target temperature (TAO) is the target temperature. The heating capacity of the heater (32) is controlled to be smaller than the temperature difference between the air temperature immediately after passing through the heater (32) when the (TAO) is equal to or lower than the predetermined temperature and the target temperature (TAO). Features.
[0011]
Thereby, it can suppress that the energy consumption of a heater (32) increases.
[0012]
  Claim4In the invention described inIn the vehicle air conditioner according to any one of claims 1 to 3,The heater (32) heats air using the high-pressure refrigerant of the vapor compression refrigerator as a heat source.An indoor heat exchanger for heating,
  The heating capacity control means (90) controls the heating capacity of the heater (32) by increasing or decreasing the compressor rotation speed of the vapor compression refrigerator.It is characterized by this.
[0013]
  According to a fifth aspect of the present invention, in the vehicle air conditioner according to the fourth aspect, the air flowing in the air conditioning casing (80) is cooled upstream of the heater (32) in the air conditioning casing (80). A cooling indoor heat exchanger (31) is arranged,
  The cooling indoor heat exchanger (31) cools the air with the low-pressure refrigerant of the vapor compression refrigerator,
  A cooling cycle is performed by cooling the air in the air conditioning casing (80) in the cooling indoor heat exchanger (31),
  On the other hand, the air in the air conditioning casing (80) is cooled by the indoor heat exchanger (31) for cooling and then heated by the heater (32) to execute the dehumidification cycle.
  Claim6In the invention described inThe vehicle air conditioner according to claim 4 or 5,The high pressure side refrigerant pressure of the vapor compression refrigerator may be equal to or higher than the critical pressure of the refrigerant.
[0014]
  Claim7In the invention described inThe vehicle air conditioner according to any one of claims 4 to 6,The vapor compression refrigerator is characterized by using carbon dioxide as a refrigerant.
[0015]
Incidentally, the reference numerals in parentheses of each means described above are an example showing the correspondence with the specific means described in the embodiments described later.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
In the present embodiment, the vehicle air conditioner according to the present invention is applied to an air conditioner for an electric vehicle, and FIG. 1 is a schematic diagram of the air conditioner according to the present embodiment.
[0017]
The compressor 10 is driven by an electric motor to suck and compress the refrigerant, and the outdoor heat exchanger 20 cools or heats the refrigerant by exchanging heat between the refrigerant and the outdoor air. The heat exchangers 31 and 32 exchange heat between the air blown into the room and the refrigerant.
[0018]
At this time, the second indoor heat exchanger 32 is installed in the air conditioning casing 80 on the downstream side of the air flow from the first indoor heat exchanger 31, and the second indoor heat exchanger 32 is provided on the core surface thereof. An air mix door 81 is provided as air volume ratio adjusting means for adjusting the air volume ratio between the amount of air passing therethrough and the volume of air flowing downstream from the second indoor heat exchanger 32.
[0019]
The air conditioning casing 80 is a container that forms an air passage through which air blown into the room flows, and the core surface is a virtual crossing with the air flow direction in the heat exchange section of the second indoor heat exchanger 32. It is a plane.
[0020]
Incidentally, in this embodiment, the refrigerant is carbon dioxide, and the pressure of the high-pressure side refrigerant, that is, the discharge pressure of the compressor 10 is increased to the critical pressure or more of the refrigerant.
[0021]
Further, on the upstream side of the air flow of the first indoor heat exchanger 31, a blower 82 that blows air into the air conditioning casing 80, and an indoor / outdoor air switch that controls the ratio of the indoor air amount and the outdoor air amount introduced into the blower 82. On the other hand, a blow-out mode switching device 84 for switching the mode of the air blown into the room is provided on the downstream side of the second indoor heat exchanger 32 in the air flow.
[0022]
In addition, as the blowing mode, a foot blowing mode that mainly blows air to the lower side of the vehicle interior, a face blowing mode that mainly blows air to the upper side of the vehicle cabin, and air is blown to the upper and lower sides of the vehicle cabin. There are at least three modes of the bi-level blowing mode.
[0023]
The first and second expansion valves 41 and 42 are decompression means for decompressing and expanding the high-pressure refrigerant compressed by the compressor 10 in an enthalpy manner. The accumulator 50 converts the refrigerant flowing into a gas-phase refrigerant and a liquid-phase refrigerant. The gas-liquid separation means separates and stores the liquid-phase refrigerant as an excess refrigerant and supplies the gas-phase refrigerant to the suction side of the compressor 10.
[0024]
  The internal heat exchanger 60 exchanges heat between the high-pressure refrigerant before being decompressed and the low-pressure refrigerant sucked into the compressor 10, and in this embodiment, the tube through which the high-pressure refrigerant flows.61And a tube through which low-pressure refrigerant flows62And the internal heat exchanger 60 is configured.
[0025]
The first bypass valve 41a opens and closes the first bypass passage 41b that guides the refrigerant flowing out of the internal heat exchanger 60 and flowing toward the first expansion valve 41 to the accumulator 50 by bypassing the first expansion valve 41. The second bypass valve 42a is an electromagnetic valve that opens and closes the second bypass passage 42b that bypasses the second expansion valve 42 and flows the refrigerant.
[0026]
In addition, the vapor compression refrigeration that moves the heat on the low temperature side to the high temperature side by the compressor 10, the outdoor heat exchanger 20, the first and second indoor heat exchangers 31, 32, the first and second expansion valves 41, 42, and the like. The machine is configured.
[0027]
FIG. 2 is a block diagram showing a control system of the vehicle air conditioner according to the present embodiment. The electronic control unit (ECU) 90 detects the air temperature immediately after passing through the first indoor heat exchanger 31. A detected temperature Te of the first temperature sensor 91, a detected temperature Tgc of the second temperature sensor 92 that detects the air temperature immediately after passing through the second indoor heat exchanger 32, a detected temperature TAM of the outside air sensor 93 that detects the outside air temperature, The detection temperature Tr of the inside air sensor 94 that detects the inside air temperature, the detection value Ts of the solar radiation sensor 95 that detects the amount of solar radiation poured into the room, and the detection pressure of the discharge pressure sensor 96 that detects the pressure of the refrigerant discharged from the compressor 10 Sp, detection temperature Td of the discharge temperature sensor 97 that detects the temperature of the refrigerant discharged from the compressor 10, detection of the indoor refrigerant temperature sensor 98 that detects the temperature of the refrigerant that has flowed out of the second indoor heat exchanger 32. Temperature setting for inputting the detected value of the air conditioning sensor such as the detected temperature Tho of the outdoor refrigerant temperature sensor 99 for detecting the temperature Tco, the temperature of the refrigerant flowing out of the outdoor heat exchanger 20, and the indoor temperature Tset desired by the passenger Based on the setting value of the panel 100, etc., the rotation speed of the compressor 10, the opening degree of the air mix door 81, the blower 82, the inside / outside air switching device 83, the blowing mode switching device 84, and the like are controlled.
[0028]
The motor drive circuit 102 supplies a drive current to the electric motor that receives the command signal from the ECU 90 and drives the compressor 10.
[0029]
Next, the characteristic operation of the vehicle air conditioner according to this embodiment will be described.
[0030]
3 and 4 are flowcharts showing a control flow executed by the ECU 90 in the vehicle air conditioner according to the present embodiment. First, the detection signals of the sensors 91 to 99, the set temperature input to the temperature setting panel 100, and the like are read. (S100, S110), a target temperature (target blowing temperature TAO) of the air blown into the vehicle interior is determined from the read value based on the following formula 1 (S120).
[0031]
[Expression 1]
TAO = Kset * Tset-Kr * Tr-Kam * Tam-Ks * Ts + C
Where Kset, Kr, Kam, Ks: Control gain
C: Constant for correction
Next, it is determined whether or not the compressor 10 needs to be started (S130). When the compressor 10 is being started, the vapor compression refrigerator is set as a heating cycle based on the target blowing temperature TAO. It is determined whether to operate, operate as a dehumidifying cycle, or operate as a cooling cycle (S140, S150, S161 to S163).
[0032]
Specifically, when the target blowing temperature TAO is equal to or higher than a predetermined temperature α (for example, 45 ° C.), the vapor compression refrigerator is operated as a heating cycle (S161), and the target blowing temperature TAO is less than the predetermined temperature α. When the temperature is higher than a predetermined temperature β (for example, 15 ° C.) lower than the predetermined temperature α, the vapor compression refrigerator is operated as a dehumidification cycle (S162), and when the target blowing temperature TAO is equal to or lower than the predetermined temperature β, steam The compression refrigerator is operated as a cooling cycle (S163). Details of each operation cycle will be described later.
[0033]
Next, regardless of the selected operation cycle, the blower 82 blower amount (blower level), the ratio of the inside air amount and the outside air amount to be introduced into the blower 82, and the blowout mode are determined based on the target blowout temperature TAO (S171). -S173, S181-S183, S191-S193).
[0034]
FIG. 5 is a chart showing the relationship between the target blowing temperature TAO and the blower level, and the blower level increases as the target blowing temperature TAO approaches the upper limit side predetermined value and the lower limit side predetermined value.
[0035]
FIG. 6 is a chart showing the target blowing temperature TAO, the ratio of the inside air amount and the outside air amount, and the ratio of the outside air increases as the target blowing temperature TAO increases.
[0036]
FIG. 7 is a chart showing the relationship between the target blowing temperature TAO and the blowing mode, and the blowing mode selected as the target blowing temperature TAO becomes larger changes in the order of face blowing mode → bi-level blowing mode → foot blowing mode. To do.
[0037]
When the heating cycle is selected, the dehumidification cycle is selected, or the bi-level blowing mode is selected when the cooling cycle is selected, the air mix door 81 is expressed by the following formula 2. When the air-cooling cycle is selected and a blowing mode other than the bi-level blowing mode is selected when the cooling cycle is selected, the air mix door is expressed by the following formula 3. The opening degree SW of 81 is determined (S203, S205).
[0038]
[Expression 2]
SW = {TAO− (Te + a)} / {Tgc− (Te + a)} × 100
A: Constant for correction
[0039]
[Equation 3]
SW = {TAO− (Te + a)} / {(Tgc + b) − (Te + a)} × 100
a, b: constants for correction
Note that b is preferably a negative number (for example, −15).
[0040]
As is clear from Equations 2 and 3, as the heating capacity of the second indoor heat exchanger 32, that is, the detected temperature Tgc of the second temperature sensor 92 increases, the amount of air that bypasses the second indoor heat exchanger 32 increases. The opening degree SW decreases so as to increase.
[0041]
Note that when the opening degree SW of the air mix door 81 is 0% (fully closed), the entire indoor surface of the second indoor heat exchanger 32 is closed and the total amount of air flowing in the air conditioning casing 80 is the second indoor heat exchange. In contrast, when the opening degree SW is 100% (fully open), the entire amount of air flowing in the air conditioning casing 80 passes through the second indoor heat exchanger 32. It is.
[0042]
Next, when the dehumidification cycle is selected, the target value of the air temperature immediately after passing through the first indoor heat exchanger 31 (target post-evaporation temperature TEO) based on the outside air temperature TAM according to the map shown in FIG. Is determined (S212), and when the cooling cycle is selected, the target post-evaporation temperature TEO is determined using the target outlet temperature TAO calculated in S120 as the target post-evaporation temperature TEO (S213).
[0043]
And when the bi-level blowing mode is selected when the heating cycle is selected, the second after-heat exchanger 32 is passed based on the following Equation 4 without determining the target post-evaporation temperature TEO. A target value for the air temperature immediately after (target post-heatsink temperature Tgco) is determined (S221, S222), and when a heating mode is selected, when a blowing mode other than the bi-level blowing mode is selected, in S120 The target post-heat radiator temperature Tgco is determined with the calculated target blowout temperature TAO as the target post-heat radiator temperature Tgco (S221, S223).
[0044]
[Expression 4]
Tgco = α × TAO + β × Te + γ
Where α, β and γ are constants such that Tgco> TAO.
Further, when the dehumidification cycle is selected and the bi-level blowing mode is selected, the target radiator post-heater temperature Tgco is determined based on the above formula 4 (S224, S225), and the dehumidification cycle is selected. When the blow mode other than the bi-level blow mode is selected, the target radiator temperature Tgco is determined using the target radiator temperature TAO calculated in S120 as the target radiator temperature Tgco (S224, S226).
[0045]
Next, when the heating cycle is selected, the target value and the current value are calculated using the fuzzy calculation method so that the detected temperature (heat radiator temperature) Tgc of the second temperature sensor 92 becomes the target heat radiator post-temperature Tgco. The amount of increase / decrease in the compressor speed is calculated from the deviation from the value (S231), and when the cooling cycle and the dehumidification cycle are selected, the detected temperature (post-evaporation temperature) Te of the first temperature sensor 91 is the target The increase / decrease amount of the compressor speed is calculated from the deviation between the target value and the current value by using the fuzzy arithmetic method so that the post-temperature TEO is obtained (S232, S233).
[0046]
When the heating cycle is selected, the target is such that the coefficient of performance of the vapor compression refrigerator is substantially maximized based on the temperature detected by the indoor refrigerant temperature sensor 98 (the refrigerant temperature at the radiator outlet side) Tco. When the high-pressure side refrigerant pressure is determined (S241) and the cooling cycle is selected, the vapor compression refrigerator is based on the temperature detected by the outdoor refrigerant temperature sensor 99 (the refrigerant temperature at the outlet side of the outdoor heat exchanger) Tho. The target high-pressure side refrigerant pressure is determined so that the coefficient of performance is substantially maximum (S243).
[0047]
Next, when the heating cycle is selected, the opening degree of the second expansion valve 42 is determined so as to be the target high-pressure side refrigerant pressure determined in S241 (S251), and the cooling cycle is selected. If so, the opening degree of the first expansion valve 41 is determined so as to be the target high-pressure side refrigerant pressure determined in S243 (S253).
[0048]
When the dehumidifying cycle is selected, the opening degree of the first and second expansion valves 41 and 42 is controlled so that the temperature of the air blown into the room becomes the target blowing temperature TAO.
[0049]
Specifically, when raising the blowing temperature, the opening degree of the first expansion valve 41 is increased and the opening degree of the second expansion valve 42 is reduced, so that the second indoor heat exchanger 32 The heat radiation amount in the outdoor heat exchanger 20 is decreased or the outdoor heat exchanger 20 is made to absorb heat while increasing the heat radiation amount.
[0050]
On the other hand, when lowering the blowing temperature, the amount of heat released from the second indoor heat exchanger 32 is reduced by reducing the opening of the first expansion valve 41 and increasing the opening of the second expansion valve 42. The amount of heat radiation in the outdoor heat exchanger 20 is increased while decreasing
[0051]
And each apparatus (actuator) is operated so that it may become the blowing mode determined by the said control step, an operation cycle, the ventilation volume, the rotation speed, and an opening degree (S260).
[0052]
Next, features of each operation cycle and this embodiment will be described.
[0053]
1. Heating cycle
During the heating cycle operation, the first expansion valve 41 and the second bypass valve 42a are closed, and the second expansion valve 42 and the first bypass valve 41a are opened to supply the refrigerant to the compressor 10 → the second indoor heat exchanger 32 → the second. 2 It circulates in order of the expansion valve 42-> outdoor heat exchanger 20-> internal heat exchanger 60 (tube 61)-> accumulator 50-> internal heat exchanger 60 (tube 62)-> compressor 10.
[0054]
At this time, if a blowing mode other than the bi-level blowing mode is selected, the opening degree SW of the air mix door 81 is normally 100%, so that the air blown into the room is sent by the second indoor heat exchanger 32. Heated by the high-temperature refrigerant discharged from the compressor 10.
[0055]
Further, after the outdoor heat exchanger 20, the refrigerant whose pressure is reduced by the second expansion valve 42 is circulated, so that the internal heat exchanger 60 does not substantially exchange heat.
[0056]
On the other hand, if the bi-level blowing mode is selected, the opening SW of the air mix door 81 is less than 100% and more than 0%, so that the air that has passed through the second indoor heat exchanger 32 becomes the second indoor heat. Hot air heated by the exchanger 32 and cold air that bypasses the second indoor heat exchanger 32 are generated, and in the bi-level blowing mode, the temperature of the air blown upward and the temperature of the air blown downward Can be made different.
[0057]
Incidentally, if α is 2, β is −1, and γ is 0, when the bi-level blowing mode is selected when Te is 15 ° C., the opening degree SW is about 50%, and the face outlet side About 25 ° C. cold air is blown out from the foot, and about 35 ° C. hot air is blown out from the foot outlet.
[0058]
2. Dehumidification cycle
During the dehumidification cycle operation, the first and second expansion valves 41 and 42 are opened, and the first and second bypass valves 41a and 42a are closed to supply the refrigerant to the compressor 10 → the second indoor heat exchanger 32 → the second expansion valve 42. -> Outdoor heat exchanger 20-> internal heat exchanger 60 (tube 61)-> first expansion valve 41-> first indoor heat exchanger 31-> accumulator 50-> internal heat exchanger 60 (tube 62)-> compressor 10 Let
[0059]
At this time, if a blowing mode other than the bi-level blowing mode is selected, the opening degree SW of the air mix door 81 is normally 100%, so that the air blown into the room is sent from the first indoor heat exchanger 31. After being cooled and dehumidified, the second indoor heat exchanger 32 is heated by the high-temperature refrigerant discharged from the compressor 10.
[0060]
On the other hand, if the bi-level blowing mode is selected, the opening SW of the air mix door 81 is less than 100% and more than 0%, so that the air that has passed through the second indoor heat exchanger 32 becomes the second indoor heat. Hot air heated by the exchanger 32 and cold air that bypasses the second indoor heat exchanger 32 are generated, and in the bi-level blowing mode, the temperature of the air blown upward and the temperature of the air blown downward Can be made different.
[0061]
3. Cooling cycle
During the cooling cycle operation, the first expansion valve 41 and the second bypass valve 42a are opened, the second expansion valve 42 and the first bypass valve 41a are closed, and the refrigerant is supplied to the compressor 10 → second indoor heat exchanger 32 → second. 2 expansion valve 42-> outdoor heat exchanger 20-> internal heat exchanger 60 (tube 61)-> first expansion valve 41-> first indoor heat exchanger 31-> accumulator 50-> internal heat exchanger 60 (tube 62)-> compressor Circulate in order of 10.
[0062]
At this time, if a blowing mode other than the bi-level blowing mode is selected, the opening degree SW of the air mix door 81 is normally 0%. Therefore, the air cooled in the first indoor heat exchanger 31 is The air is blown into the room without exchanging heat with the second indoor heat exchanger 32.
[0063]
Further, after the first indoor heat exchanger 31, the refrigerant whose pressure is reduced by the first expansion valve 41 is circulated, so that the internal heat exchanger 60 exchanges heat between the high-pressure refrigerant and the low-pressure refrigerant. Therefore, the enthalpy of the refrigerant flowing into the first indoor heat exchanger 31 can be reduced, and the refrigeration capacity can be increased.
[0064]
On the other hand, if the bi-level blowing mode is selected, the opening SW of the air mix door 81 is less than 100% and more than 0%, so the air that has passed through the second indoor heat exchanger 32 is Hot air heated by the heat exchanger 32 and cold air that bypasses the second indoor heat exchanger 32 are generated, and in the bi-level blowing mode, the temperature of the air blown upward and the air blown downward The temperature can be made different.
[0065]
By the way, when the bi-level blowing mode is selected, the heating capacity of the second indoor heat exchanger 32 so that the air temperature immediately after passing through the second indoor heat exchanger 32 is higher than the target blowing temperature TAO. However, in this embodiment, when the air conditioning load is large, in principle, the refrigerant pressure on the high pressure side is set to be equal to or higher than the critical pressure amount, although the power consumption of the compressor 10, that is, the vapor compression refrigerator is increased. It is easy to generate a relatively high temperature. Therefore, the temperature of the air blown upward can be made different from the temperature of the air blown downward while suppressing an increase in power consumption.
[0066]
(Second Embodiment)
As shown in FIG. 9, in the present embodiment, when the bi-level blowing mode is selected, the air temperature immediately after passing through the second indoor heat exchanger 32 when the target blowing temperature TAO is equal to or higher than a predetermined temperature, The temperature difference from the target blowing temperature TAO is smaller than the temperature difference between the air temperature immediately after passing through the second indoor heat exchanger 32 when the target blowing temperature TAO is equal to or lower than the predetermined temperature and the target blowing temperature TAO. The heating capacity of the two indoor heat exchanger 32, that is, the target radiator post-heater temperature Tgco is determined.
[0067]
Next, the function and effect of this embodiment will be described.
[0068]
As described above, when the bi-level blowing mode is selected, the second indoor heat exchanger 32 is set such that the air temperature immediately after passing through the second indoor heat exchanger 32 is higher than the target blowing temperature TAO. Since the heating capacity is controlled, the power consumption of the vapor compression refrigerator increases.
[0069]
On the other hand, in this embodiment, when the target blowing temperature TAO becomes equal to or higher than the predetermined temperature, the temperature difference between the air temperature immediately after passing through the second indoor heat exchanger 32 and the target blowing temperature TAO is the target blowing temperature. Since the temperature difference between the air temperature immediately after passing through the second indoor heat exchanger 32 when the temperature TAO is equal to or lower than the predetermined temperature and the target blowing temperature TAO is made smaller, the power consumption of the vapor compression refrigerator increases. Can be suppressed.
[0070]
In FIG. 9, the increase amount of the target radiator post-heater temperature Tgco is changed based on the target blowing temperature TAO. However, since the target blowing temperature TAO has a correlation with the outside air temperature and the inside air temperature, the inside air temperature or the outside air When the temperature is equal to or higher than a predetermined temperature, the temperature difference between the air temperature immediately after passing through the second indoor heat exchanger 32 and the target blowing temperature TAO is the second indoor when the internal air temperature or the external air temperature is equal to or lower than the predetermined temperature The heating capacity of the second indoor heat exchanger 32, that is, the target post-radiator temperature Tgco, may be determined so as to be smaller than the temperature difference between the air temperature immediately after passing through the heat exchanger 32 and the target blowing temperature TAO.
[0071]
(Other embodiments)
In this embodiment, the refrigerant is carbon dioxide, and the pressure of the high-pressure side refrigerant, that is, the discharge pressure of the compressor 10 is increased to the critical pressure or more of the refrigerant. Needless to say, may be less than the critical pressure.
[0072]
Further, in the above-described embodiment, the second indoor heat exchanger 32, that is, the high pressure side heat exchanger of the vapor compression refrigerator is used as the heater. However, the present invention is not limited to this, for example, FIG. As shown in FIG. 10, an electric heater may be used as the heater 32.
[Brief description of the 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 showing a control system of the air conditioner according to the embodiment of the present invention.
FIG. 3 is a control flowchart of the air conditioner according to the embodiment of the present invention.
FIG. 4 is a control flowchart of the air conditioner according to the embodiment of the present invention.
FIG. 5 is a characteristic diagram showing a relationship between a target blowing temperature TAO and a blower level.
FIG. 6 is a characteristic diagram showing a ratio of a target blowing temperature TAO, an inside air amount, and an outside air amount.
FIG. 7 is a characteristic diagram showing a relationship between a target blowing temperature TAO and a blowing mode.
FIG. 8 is a characteristic diagram showing a relationship between an air temperature TAM and a target post-evaporation temperature TEO.
FIG. 9 is a characteristic diagram showing the relationship between the target radiator temperature Tgco and the target outlet temperature TAO.
FIG. 10 is a schematic view of an air conditioner according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Compressor, 20 ... Outdoor heat exchanger, 31 ... 1st indoor heat exchanger,
32 ... 2nd indoor heat exchanger, 41 ... 1st expansion valve, 42 ... 2nd expansion valve,
81 ... Air mix door.

Claims (7)

It has a foot blow mode that blows air mainly to the lower side of the passenger compartment, a face blow mode that blows air mainly to the upper side of the passenger compartment, and a bi-level blow mode that blows air to the upper and lower sides of the passenger compartment. , An air conditioner for a vehicle that harmonizes the air blown into the passenger compartment,
An air conditioning casing (80) that constitutes an air passage through which air blown into the passenger compartment flows;
A heater (32) disposed in the air conditioning casing (80) for heating the air flowing in the air conditioning casing (80) and capable of controlling the heating capacity ;
Air volume ratio between the amount of air that is provided in the air conditioning casing (80) and bypasses the heater (32) and flows downstream, and the amount of air that is heated by the heater (32) and flows downstream Air volume ratio adjusting means (81) for adjusting
Of the downstream side portion of the heater (32) in the air conditioning casing (80), a foot that opens to a portion on the side through which the warm air that has passed through the heater (32) flows and blows air downward in the passenger compartment. The air outlet,
Of the downstream portion of the heater (32) in the air-conditioning casing (80), a face blower that opens to a portion on the side through which the cold air that bypasses the heater (32) flows and blows air upward in the passenger compartment. Exit,
An air outlet mode switching device (84) for opening and closing the foot air outlet and the face air outlet and switching between the foot air outlet mode, the face air outlet mode and the bi-level air outlet mode;
Heating capacity control means (90) for controlling the heating capacity of the heater (32);
The air volume ratio determining means (S201 , ) for determining the air volume ratio of the air volume ratio adjusting means (81) so that the air volume bypassing the heater (32) increases as the heating capacity of the heater (32) increases . S202, S204, S205 ),
In the state where the total amount of air flowing in the air conditioning casing (80) flows around the heater (32), the opening degree (SW) of the air volume ratio adjusting means (81) is 0%, and the air conditioning casing (80) When the opening degree (SW) of the air volume ratio adjusting means (81) is 100% in a state where the total amount of air flowing through the heater (32) passes, the air conditioning casing (80) When the bi-level blowing mode is selected during heating in which the air inside is heated by the heater (32), the air volume ratio adjusting means (81) is selected by the air volume ratio determining means (S201, S202, S204, S205). The opening degree (SW) is less than 100% and more than 0%,
In the bi-level blowing mode, hot air that has passed through the heater (32) and cold air that bypasses the heater (32) are generated, and the temperature of the air that is blown downward from the temperature of the air that is blown upward. Is becoming higher,
Furthermore, the heating capacity control means (90)
When the foot blowing mode and the face blowing mode are selected during the heating, the air temperature immediately after passing through the heater (32) is a temperature (TAO) corresponding to the target temperature (TAO) of the air blown into the passenger compartment. First control means (S223) for controlling the heating capacity of the heater (32) to be Tgco),
When the bi-level air outlet mode during the heating is selected, the heater (32) high rather than air temperature immediately after passing through the air target temperature to be blown into the passenger compartment (TAO), and wherein the first control A vehicle air conditioner comprising: second control means (S222) for controlling the heating capacity of the heater (32) so that the temperature is higher than the temperature given by the means (S223) . The first control means (S223) is configured to control the air temperature immediately after passing through the heater (32) when the foot blowing mode and the face blowing mode are selected during the heating. The vehicle air conditioner according to claim 1 , wherein the heating capacity of the heater (32) is controlled so as to be the same temperature (Tgco) as the target temperature (TAO) . Immediately after the heating capacity control means (90), said when the when the during heating bilevel air outlet mode is selected target temperature (TAO) is equal to or greater than a predetermined temperature, passing through the heater (32) The temperature difference between the air temperature and the target temperature (TAO) is such that the air temperature immediately after passing through the heater (32) when the target temperature (TAO) is equal to or lower than the predetermined temperature and the target temperature (TAO) The vehicle air conditioner according to claim 1 or 2 , wherein the heating capacity of the heater (32) is controlled so as to be smaller than the temperature difference. The heater (32) is an indoor heat exchanger for heating that heats air using a high-pressure refrigerant of a vapor compression refrigerator as a heat source ,
The heating capacity control means (90), one of the claims 1 to 3, characterized in that for controlling the heating capacity of the heater (32) by increasing or decreasing the compressor speed of the vapor compression type refrigerator The vehicle air conditioner according to claim 1 . In the air conditioning casing (80), on the upstream side of the heater (32), a cooling indoor heat exchanger (31) for cooling the air flowing in the air conditioning casing (80) is disposed,
The cooling indoor heat exchanger (31) cools the air with the low-pressure refrigerant of the vapor compression refrigerator,
A cooling cycle is performed by cooling air in the air conditioning casing (80) in the indoor heat exchanger (31) for cooling,
Meanwhile, the air in the air conditioning casing (80) is cooled by the cooling indoor heat exchanger (31) and then heated by the heater (32) to execute a dehumidification cycle. The vehicle air conditioner according to claim 4. 6. The vehicle air conditioner according to claim 4, wherein a high-pressure side refrigerant pressure of the vapor compression refrigerator may be equal to or higher than a critical pressure of the refrigerant. The vehicle air conditioner according to any one of claims 4 to 6, wherein the vapor compression refrigerator uses carbon dioxide as a refrigerant.

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