JPH06143996A - Vehicle air conditioner - Google Patents

Abstract

PURPOSE:To provide a vehicle air conditioner capable of dehumidification and heating without increasing the power required. CONSTITUTION:A control device 9 to control an outside air blower 4 and an inside air blower 5 controls the inside air blower 5 so as to increase the volume of the inside air through a blower driving circuit 5a when the fin temperature of a heat exchanger 6 detected by a fin temperature sensor 7 is lower than the first set value, while controlling the inside air blower 5 so as to reduce the inside air volume through the blower driving circuit 5a when the fin temperature is higher than the first set value and higher than the second set value.

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 for dehumidifying the inside air by exchanging heat between the outside air and the inside air.

[0002]

2. Description of the Related Art In recent years, in electric vehicles and the like that cannot sufficiently secure a heat source for heating, the heating performance is improved by reducing the amount of outside air introduced (increasing the amount of circulation of inside air) during heating to reduce ventilation loss. Although there is a demand, in this case, there is a problem that the window glass becomes cloudy due to the increase in humidity in the vehicle interior. Therefore, conventionally, there is a method of preventing the fogging of the window glass by activating the refrigeration cycle to perform the dehumidifying operation when the humidity in the vehicle compartment is high. However, when the dehumidification operation is continued, the temperature inside the vehicle is lowered as the amount of heat absorbed during dehumidification is released to the outside of the vehicle. On the other hand, in Japanese Patent Publication No. 3-49007,
An air conditioner using an electronic heater that compensates for heat absorption loss during dehumidification is disclosed.

[0003]

However, the air conditioner disclosed in the above publication has a problem that the electric power is increased by the electric heating by the electronic heater. The present invention has been made based on the above circumstances, and an object thereof is to provide an air conditioning apparatus for a vehicle that can perform a dehumidifying heating operation without increasing power.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an outside air introduction port for introducing outside air and an inside air introduction port for introducing inside air with a ventilation duct, and this ventilation duct. Blower means for introducing outside air and inside air into the vehicle, and adjusting the introduction ratio of the outside air amount introduced from the outside air introduction port and the introduction ratio of the inside air amount introduced from the inside air introduction port. Means, a heat exchanger disposed in the air duct for heat exchange between the outside air introduced from the outside air inlet and the inside air introduced from the inside air inlet, and an average heat transfer surface of the heat exchanger A heat transfer surface temperature detecting means for detecting the temperature, a dehumidification amount obtained by the heat exchanger according to the introduction ratio of the outside air amount and the inside air amount at a certain outside air temperature, and the average heat transfer of the heat exchanger at that time. Storage means for storing the relationship with the surface temperature, Based on the relationship between the dehumidification amount and the average heat transfer surface temperature stored in the storage means, the target average heat transfer surface temperature at which the dehumidification amount obtained in the heat exchanger is maximum is set according to the outside air temperature. The blower means and the inside / outside air introduction amount are provided so that the average heat transfer surface temperature detected by the heat transfer surface temperature detection means becomes the target average heat transfer surface temperature calculated by the calculation means. The technical means including the control means for controlling the adjusting means is employed.

[0005]

In the vehicle air conditioner of the present invention having the above structure, the inside air is dehumidified by exchanging heat between the outside air introduced through the outside air inlet and the inside air introduced through the inside air inlet. From the correlation between the dehumidification amount obtained by this heat exchanger and the average heat transfer surface temperature of the heat exchanger, which is determined by the introduction ratio of the outside air amount and the inside air amount, the target for the maximum dehumidification amount according to the outside air temperature Obtain the average heat transfer surface temperature and set the introduction ratio of the outside air amount and the inside air amount so that the average heat transfer surface temperature of the actual heat exchanger detected by the heat transfer surface temperature detection means becomes the target average heat transfer surface temperature. Adjusted. The introduction ratio of the outside air amount and the inside air amount is controlled by controlling the blower means and the inside / outside air introduction amount adjusting means by the control means. The amount of heat released from the inside air during dehumidification is absorbed into the outside air by the heat exchanger and released into the vehicle interior, so that the temperature inside the vehicle interior does not decrease due to dehumidification.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a vehicle air conditioner of the present invention will be described with reference to FIGS. FIG. 1 is an overall schematic view of a vehicle air conditioner. The vehicle air conditioner 1 of this embodiment includes an outside air duct 2, an inside air duct 3, an outside air side blower 4, an inside air side blower 5, a heat exchanger 6, a fin temperature sensor 7, an outside air temperature sensor 8, and a controller 9. . The outside air duct 2 connects the outside air introduction port 10 that opens outside the vehicle interior and the vehicle interior, and guides the outside air introduced through the outside air introduction port 10 into the vehicle interior. The inside air duct 3 communicates with the inside air introducing port 11 opening into the inside of the vehicle and the inside of the vehicle, and guides the inside air introduced from the inside air introducing port 11 into the inside of the vehicle. The outside air blower 4 introduces outside air into the outside air duct 2 and sends the outside air into the vehicle interior, and the amount of blown air (rotation speed) is variable according to the voltage value applied via the blower drive circuit 4a. The inside air side blower 5 introduces the inside air into the inside air duct 3 and sends the inside air into the vehicle interior, and the amount of blown air (rotation speed) is variable according to the voltage value applied via the blower drive circuit 5a. The heat exchanger 6 has one end arranged in the outside air duct 2 and the other end arranged in the inside air duct 3, and heat of the outside air introduced into the outside air duct 2 and the inside air introduced into the inside air duct 3 Exchange. The fin temperature sensor 7 is attached to a heat transfer fin (not shown) of the heat exchanger 6, and the fin temperature TF of the heat exchanger 6 (average heat transfer surface temperature)
To detect. The outside air temperature sensor 8 detects the temperature of outside air.

The controller 9 includes a memory circuit 9a and an arithmetic circuit 9
A microcomputer having a built-in b controls the outside air blower 4 and the inside air blower 5 via the blower drive circuits 4a and 5a based on the information from the fin temperature sensor 7 and the outside air temperature sensor 8. The memory circuit 9a stores the dehumidification amount w obtained by the heat exchanger 6 according to the introduction ratio of the outside air amount and the inside air amount at a certain outside air temperature, and the fin temperature T of the heat exchanger 6 at that time.
The relationship with F (shown in FIG. 2) is stored in advance. Based on the relationship between the dehumidification amount w and the fin temperature TF stored in the storage circuit 9a, the arithmetic circuit 9b sets the target fin temperature TFP that maximizes the dehumidification amount w obtained by the heat exchanger 6 to the outside air temperature Ta.
Is calculated according to the following equation.

## EQU1 ## TFP = a.Ta + b (a and b are constants) Note that FIG. 3 shows the relationship between the target fin temperature TFP and the outside air temperature Ta expressed by the equation 1.

Next, the operation of this embodiment will be described based on the processing procedure of the control device 9. FIG. 4 is a flowchart showing the processing procedure of the control device 9. First, the outside air temperature Ta and the fin temperature TF detected by the outside air temperature sensor 8 and the fin temperature sensor 7 are input (step 100). Next, the target fin temperature TFP is obtained from the outside air temperature Ta based on the above equation 1 (step 101). Then, it is judged whether or not the actual fin temperature TF detected by the fin temperature sensor 7 is larger than the first set value (target fin temperature TFP-α) (step 102), and if it is smaller (NO),
Since the introduction ratio of the inside air amount GR to the outside air amount is small, the inside air side blower 5 is controlled via the blower drive circuit 5a so as to increase the inside air amount GR while keeping the outside air amount constant (step 103). When it is determined in step 102 that the actual fin temperature TF is higher than the first set value (Y
ES) determines whether the actual fin temperature TF is lower than the second set value (target fin temperature TFP + α) (step 104). If the result of this determination is NO (the actual fin temperature TF is higher than the second set value), the introduction ratio of the inside air amount GR to the outside air amount is large, so the inside air amount GR is reduced while the outside air amount remains constant. Thus, the inside air side blower 5 is controlled via the blower drive circuit 5a (step 105).

As a result, the inside air amount GR is controlled within a certain range in which the maximum dehumidification amount w is obtained with respect to the outside air condition at that time, so that the dehumidification of the vehicle interior can be effectively performed. Further, the amount of heat released from the inside air at the time of dehumidification is absorbed by the heat exchanger 6 to the outside air and released into the passenger compartment, so that the refrigeration cycle is operated to dehumidify as in the conventional case. It is possible to prevent a temperature decrease in the vehicle compartment due to dehumidification.

Next, a second embodiment of the present invention will be described. As shown in FIG. 5, the vehicle air conditioner 1 of the present embodiment,
Blower duct 1 having outside air inlet 10 and inside air inlet 11
2, a suction type blower 13 for introducing the outside air and the inside air into the blower duct 12, and an inside / outside air switching damper 14 for adjusting the introduction ratio of the outside air introduction amount and the inside air introduction amount. The blower 13 and the inside / outside air switching damper 14 include a blower drive circuit 13a and a damper drive circuit 14a, respectively.
It is controlled by the control device 9 via the. The operation of this embodiment will be described based on the processing procedure of the control device 9. FIG. 6 is a flowchart showing the processing procedure of the control device 9. First, the outside air temperature Ta and the fin temperature TF detected by the outside air temperature sensor 8 and the fin temperature sensor 7 are input (step 200). Next, the target fin temperature TFP is obtained from the outside air temperature Ta (step 201). Then, the actual fin temperature TF detected by the fin temperature sensor 7
Is larger than the first set value (target fin temperature TFP-α) (step 202), and is smaller (N).
O), since the introduction ratio of the inside air amount GR to the outside air amount is small, the inside / outside air switching damper 14 is driven so as to increase the inside air amount GR while keeping the outside air amount constant (step 20).
3). In step 202, the actual fin temperature TF is the first
When it is determined that the temperature is higher than the set value (YES), the actual fin temperature TF is the second set value (target fin temperature TFP +
It is determined whether it is smaller than α) (step 204).
When the determination result is NO (the actual fin temperature TF is higher than the second set value), the introduction ratio of the inside air amount GR to the outside air amount is large, and therefore the outside air amount remains constant and the inside air amount G remains constant.
The inside / outside air switching damper 14 is driven so as to reduce R (step 205). As a result, as in the case of the above-described first embodiment, it is possible to prevent the window glass from becoming fogged due to dehumidification of the vehicle interior without lowering the vehicle interior temperature.

Next, a third embodiment of the present invention will be described. The vehicle air conditioner 1 of the present embodiment, as shown in FIG.
Similar to the first embodiment, an outside air duct 2, an inside air duct 3, an outside air side blower 4, and an inside air side blower 5 are provided, and a heat pipe 15 is used as the heat exchanger 6 shown in the first embodiment. In the present embodiment, since the fin temperature of the heat transfer fins 15a provided on the heat pipe 15 changes following the pipe internal pressure of the heat pipe 15, the pressure sensor 1 that detects the pipe internal pressure instead of the fin temperature sensor 7 is used.
6 is mounted, and the optimum internal air amount GR is set based on the pipe internal pressure detected by the pressure sensor 16.

Next, a fourth embodiment of the present invention will be described. The vehicle air conditioner 1 of the present embodiment, as shown in FIG.
The refrigerant evaporator 17 of the refrigeration cycle S is arranged in the blower duct 12, and the opening / closing valves 18 and 19 provided at the refrigerant inlet and the refrigerant outlet of the refrigerant evaporator 17 are closed to close the refrigerant evaporator 1.
7 is hermetically sealed to function as a heat pipe heat exchanger. The operations of the blower 13 and the inside / outside air switching damper 14 are the same as those in the second embodiment. The refrigeration cycle S has a known structure in which the refrigerant compressor 20, the refrigerant condenser 21, the receiver 22, the expansion valve 23, and the refrigerant evaporator 17 are annularly connected. A heater core 24 that heats the air passing therethrough is disposed downstream (downwardly) of the refrigerant evaporator 17, and the amount of air passing through the heater core 24 is adjusted by the air mix damper 25.

[Modification] In the above embodiment, the heat exchanger 6 is used.
Although the fin temperature sensor 7 and the pressure sensor 16 are shown as the heat transfer surface temperature detecting means for detecting the average heat transfer surface temperature of the above, an air temperature sensor for detecting the outlet air temperature of the heat exchanger 6 may be applied. .

[0014]

The vehicle air conditioner of the present invention can dehumidify the inside air by exchanging heat between the outside air and the inside air and prevent the window glass from fogging. Further, since the amount of heat released by dehumidifying the inside air is absorbed in the outside air and released into the vehicle interior, it is possible to prevent the temperature inside the vehicle interior from lowering due to dehumidification without increasing the power.

[Brief description of drawings]

FIG. 1 is an overall schematic diagram of a vehicle air conditioner according to a first embodiment.

FIG. 2 is a graph showing the relationship among the amount of inside air, the fin temperature, and the amount of dehumidification.

FIG. 3 is a graph showing a relationship between a target fin temperature and an outside air temperature.

FIG. 4 is a flowchart showing a processing procedure of the control device according to the first embodiment.

FIG. 5 is an overall schematic diagram of a vehicle air conditioner according to a second embodiment.

FIG. 6 is a flowchart showing a processing procedure of the control device according to the second embodiment.

FIG. 7 is an overall schematic diagram of a vehicle air conditioner according to a third embodiment.

FIG. 8 is an overall schematic diagram of a vehicle air conditioner according to a fourth embodiment.

[Explanation of symbols]

 1 Vehicle Air Conditioner 2 Outside Air Duct (Blower Duct) 3 Inside Air Duct (Blower Duct) 4 Outside Air Blower (Blower Means / Inside / Outside Air Intake Amount Adjusting Means) 5 Inside Air Side Blower (Blower Means / Inside / Outside Air Intake Adjusting Means) 6 Heat Exchanger 7 Fin Temperature Sensor (Heat Transfer Surface Temperature Detection Means) 9 Control Device (Control Means) 9a Memory Circuit (Memory Means) 9b Arithmetic Circuit (Calculation Means) 10 Outside Air Inlet 11 Inside Air Inlet 12 Blower Duct 13 Blower (Blower means) 14 Inside / outside air switching damper (inside / outside air introduction amount adjusting means) 15 Heat pipe 16 Pressure sensor (heat transfer surface temperature detecting means)

Claims (1)

[Claims] Claims: 1. a) a blower duct that connects an outside air introduction port for introducing outside air and an inside air introduction port for introducing inside air to a vehicle interior; and b) introducing the outside air and the inside air into the ventilation duct to introduce the air into the vehicle. An air blowing means for sending the air to the room; c) an inside / outside air introduction amount adjusting means for adjusting an introduction ratio of the outside air amount introduced from the outside air introduction port and the inside air amount introduced from the inside air introduction port; and d) in the air blowing duct. A heat exchanger that is arranged to exchange heat between the outside air introduced through the outside air inlet and the inside air introduced through the inside air inlet; and e) heat transfer for detecting the average heat transfer surface temperature of the heat exchanger. A surface temperature detecting means, and f) the dehumidification amount obtained by the heat exchanger according to the introduction ratio of the outside air amount and the inside air amount at a certain outside air temperature, and the average heat transfer surface temperature of the heat exchanger at that time. Storage means for storing the relationship,
And, based on the relationship between the dehumidifying amount and the average heat transfer surface temperature stored in the storage means, the target average heat transfer surface temperature at which the dehumidifying amount obtained in the heat exchanger is maximum is set according to the outside air temperature. The blower means and the inside / outside air introduction amount are provided so that the average heat transfer surface temperature detected by the heat transfer surface temperature detection means becomes the target average heat transfer surface temperature calculated by the calculation means. A vehicle air conditioner comprising: a control unit that controls an adjustment unit.