Air-conditioning system

• US 20070209789A1
• Filed: 03/08/2007
• Published: 09/13/2007
• Est. Priority Date: 03/10/2006
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Oomura, Mitsuyo, Wakisaka, Takeshi, Hirose, Katsutoshi
• Granted Patent: US 7,997,331 B2
• Time in Patent Office: Days
• US Class Current: 165/202
• CPC Class Codes: B60H 1/3207 for minimizing the humidity of the air
• CPC Class Codes: B60H 1/323 characterised by comprising auxiliary or multiple systems, e.g. plurality of evaporators, or by involving auxiliary cooling devices
• CPC Class Codes: B60H 2001/00961 comprising means for defrosting outside heat exchangers
• CPC Class Codes: B60H 2001/3261 of the air at an evaporating unit
• CPC Class Codes: F25B 2600/021 Inverters therefor
• CPC Class Codes: F25B 2600/0253 with variable speed
• CPC Class Codes: F25B 2600/112 of evaporator fans
• CPC Class Codes: F25B 2700/2104 of an indoor room or compartment
• CPC Class Codes: F25B 2700/2106 of fresh outdoor air
• CPC Class Codes: F25B 2700/21173 at the outlet
• CPC Class Codes: F25B 47/02 Defrosting cycles
• CPC Class Codes: F25B 49/022 Compressor control arrangements
• CPC Class Codes: F25B 5/02 arranged in parallel

Abstract

An air-conditioning system preventing the vented air temperature of a rear seat evaporator from not being able to be adjusted, wherein an electronic control system judges that the surface of the rear seat evaporator is frosting up when a target blowing rate of the rear seat blower is lower than a predetermined value, a detection temperature of an evaporator vented air temperature sensor is lower than TEa, and a detection temperature of the outside air temperature sensor is lower than TAMa; TEO is raised at this time, so an electric motor of an electric compressor is stopped; refrigerant no longer flows into the rear seat evaporator for this reason and the surface of the rear seat evaporator rises in temperature, so the rear seat evaporator can be defrosted; and even if the surface of the rear seat evaporator frosts, the rear seat evaporator 8 can be defrosted, so the vented air temperature of the rear seat evaporator can be prevented from not being able to be adjusted.

Claims

1. An air-conditioning system provided with:

a compressor for compressing a refrigerant,

first and second blowers,

a first evaporator forming a refrigeration cycle apparatus along with said compressor and cooling air blown from said first blower by evaporation of said refrigerant,

a second evaporator arranged in parallel with said first evaporator in the flow of refrigerant from said compressor and cooling air blown from said second blower by evaporation of said refrigerant,

a temperature detecting means for detecting a temperature of vented air blown out from said first evaporator, and

a compressor control means for controlling said compressor to bring a vented air temperature blown out from said first evaporator close to a target temperature based on a detection value of said temperature detecting means,

a frosting judging means for judging that the surface of said second evaporator is not frosting up when either or both the blowing rate of said second blower is a predetermined flow rate or more and said detection value of said temperature detecting means is a first temperature or more and judging that the surface of said second evaporator is frosting up when a blowing rate of said second blower is less than said predetermined flow rate and said detection value of temperature detecting means is less than said first temperature, and

a refrigerant control means for reducing the amount of discharge of the refrigerant from said compressor for defrosting said second evaporator when it is judged that the surface of said second evaporator is frosting up by said frosting judging means.

2. An air-conditioning system as set forth in claim 1, wherein provided with:

a heater unit for heating cool air from said first evaporator,

a bypass passage for bypassing said heater unit and carrying cool air from said first evaporator,

an air mix door for adjusting a ratio of the amount of air flowing into said heater unit and the amount of air flowing into said bypass passage to adjust the temperature of the vented air blown out from the vents into a vehicle compartment,

a venting temperature control means for controlling said air mix door to bring the temperature of the vented air blown out from said vents close to a target vented air temperature,

an outside air temperature detecting means for detecting an air temperature outside the vehicle compartment,

first temperature calculating means for calculating said target temperature based on the detection temperature of said outside air temperature detecting means and said target vented air temperature, and

a second temperature calculating means for adding a predetermined value to a value calculated by said first temperature calculating means, where

when it is judged that the surface of said second evaporator is not frosting up by said frosting judging means, said refrigerant control means uses a value found by the first temperature calculating means as the target temperature to control said compressor, while when it is judged that the surface of said second evaporator is frosting up by said frosting judging means, said refrigerant control means uses a value found by the second temperature calculating means as the target temperature to control said compressor and

said refrigerant control means uses the value found by said second temperature calculating means as the target temperature to control the compressor so as to reduce the amount of discharge of the refrigerant from said compressor.

3. An air-conditioning system as set forth in claim 1, wherein said refrigerant control means stops said compressor to reduce the amount of discharge of the refrigerant from said compressor.

8. An air-conditioning system as set forth in claim 1, wherein said frosting judging means raises said predetermined flow rate the greater the blowing rate of said first blower when judging that the surface of said second evaporator is frosting up.

9. An air-conditioning system as set forth in claim 1, further provided with

an outside air temperature detecting means for detecting the air temperature outside the vehicle compartment, wherein

said frosting judging means judges that the surface of said second evaporator is not frosting up when the detection temperature of the outside air temperature detecting means is a second temperature or more and judges that the surface of said second evaporator is frosting up when the detection temperature of the outside air temperature detecting means is less than said second temperature, a blowing rate of said second blower is less than a predetermined amount, and a detection value of said temperature detecting means is less than a first temperature.

4. An air-conditioning system provided with:

a compressor for compressing a refrigerant,

first and second blowers,

a first evaporator forming a refrigeration cycle apparatus along with said compressor and cooling air blown from said first blower by evaporation of said refrigerant,

a second evaporator arranged in parallel with said first evaporator in the flow of refrigerant from said compressor and cooling air blown from said second blower by evaporation of said refrigerant,

a temperature detecting means for detecting a temperature of vented air blown out from said first evaporator,

a compressor control means for controlling said compressor to bring a vented air temperature blown out from said first evaporator close to a target temperature based on a detection value of said temperature detecting means,

a frosting judging means for judging that the surface of said second evaporator is not frosting up when either or both the blowing rate of said second blower is a predetermined flow rate or more and said detection value of said temperature detecting means is a first temperature or more and judging that the surface of said second evaporator is frosting up when a blowing rate of said second blower is less than said predetermined flow rate and said detection value of temperature detecting means is less than said first temperature, and

a blowing control means for increasing the blowing rate from said second blower to defrost said second evaporator when it is judged that the surface of said second evaporator is frosting up by said frosting judging means.

5. An air-conditioning system as set forth in claim 4, provided with:

a heater unit for heating cool air from said first evaporator,

a bypass passage for bypassing said heater unit and carrying cool air from said first evaporator,

an air mix door for adjusting a ratio of the amount of air flowing into said heater unit and the amount of air flowing into said bypass passage to adjust the temperature of the vented air blown out from the vents into a vehicle compartment,

a venting temperature control means for controlling said air mix door to bring the temperature of the vented air blown out from said vents close to a target vented air temperature,

a first blowing rate calculating means for calculating a target blowing rate of said second blower based on said target vented air temperature, and

a second blowing rate calculating means for adding a predetermined amount to a target blowing rate calculated by said first blowing rate calculating means, wherein

when it is judged that the surface of said second evaporator is not frosting up by said frosting judging means, said blowing control means controls said second blower so as to make a blowing rate of said second blower approach the target blowing rate found by said first blowing rate calculating means, while when it is judged that the surface of said second evaporator is frosting up, said blowing control means controls said second blower so as to make a blowing rate of said second blower approach the blowing rate found by said second blowing rate calculating means and

said blowing control means controls said second blower so as to increase the blowing rate from said second blower so as to make a blowing rate of said second blower approach the blowing rate found by said second blowing rate calculating means.

6. An air-conditioning system provided with:

a compressor for compressing a refrigerant,

first and second blowers,

a first evaporator forming a refrigeration cycle apparatus along with said compressor and cooling air blown from said first blower by evaporation of said refrigerant,

a second evaporator arranged in parallel with said first evaporator in the flow of refrigerant from said compressor and cooling air blown from said second blower by evaporation of said refrigerant,

a temperature detecting means for detecting a temperature of vented air blown out from said first evaporator, and

a compressor control means for controlling said compressor to bring a vented air temperature blown out from said first evaporator close to a target temperature based on a detection value of said temperature detecting means,

a frosting judging means for judging that the surface of said second evaporator is not frosting up when either or both the blowing rate of said second blower is a predetermined flow rate or more and said detection value of said temperature detecting means is a first temperature or more and judging that the surface of said second evaporator is frosting up when a blowing rate of said second blower is less than said predetermined flow rate and said detection value of temperature detecting means is less than said first temperature, and

a blowing control means for decreasing the blowing rate from said first blower to defrost said second evaporator when it is judged that the surface of said second evaporator is frosting up by said frosting judging means.

7. An air-conditioning system as set forth in claim 6, wherein

a heater unit for heating cool air from said first evaporator,

a bypass passage for bypassing said heater unit and carrying cool air from said first evaporator,

an air mix door for adjusting a ratio of the amount of air flowing into said heater unit and the amount of air flowing into said bypass passage to adjust the temperature of the vented air blown out from the vents into a vehicle compartment,

a venting temperature control means for controlling said air mix door to bring the temperature of the vented air blown out from said vents close to a target vented air temperature,

a first blowing rate calculating means for calculating a target blowing rate of said first blower based on said target vented air temperature, and

a second blowing rate calculating means for adding a predetermined amount to a target blowing rate calculated by said first blowing rate calculating means, wherein

when it is judged that the surface of said second evaporator is not frosting up by said frosting judging means, said blowing control means controls said first blower so as to make a blowing rate of said first blower approach the target blowing rate found by said first blowing rate calculating means, while when it is judged that the surface of said second evaporator is frosting up, said blowing control means controls said first blower so as to make a blowing rate of said first blower approach the blowing rate found by said second blowing rate calculating means and

said blowing control means controls said first blower so as to decrease the blowing rate from said first blower so as to make a blowing rate of said first blower approach the blowing rate found by said second blowing rate calculating means.