Air conditioner with control of compressor

• US 6,955,060 B2
• Filed: 03/25/2004
• Issued: 10/18/2005
• Est. Priority Date: 04/16/2003
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Yoshida, Makoto, Oomura, Mitsuyo, Homan, Toshinobu
• Primary Examiner(s): NORMAN, MARC E
• Application Number:
  US10/809,131
• Publication Number:
  US 20040206102A1
• Time in Patent Office: 572 Days
• Field of Search: 621/33, 622/281, 622/284, 622/29, 622/40
• US Class Current: 62/228.4
• CPC Class Codes: B60H 1/322 for improving the stop or idling operation of the engine
• CPC Class Codes: B60H 2001/3261 of the air at an evaporating unit
• CPC Class Codes: B60H 2001/3266 related to the operation of the vehicle
• CPC Class Codes: B60H 2001/327 related to a compressing unit
• CPC Class Codes: B60H 2001/3292 Compressor drive is electric only
• CPC Class Codes: F25B 2500/19 Calculation of parameters
• CPC Class Codes: F25B 2500/26 characterised by the startup of the refrigeration cycle
• CPC Class Codes: F25B 2600/0253 with variable speed
• 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 2700/21172 at the inlet
• CPC Class Codes: F25B 2700/21173 at the outlet
• CPC Class Codes: F25B 49/025 Motor control arrangements

Abstract

In an air conditioner, a target compressor rotation speed is determined based on a target air temperature, which represents an air conditioning load, when an electric compressor is started from a stop state. Thus, an evaporator air temperature can be approximated to a target evaporator air temperature, more quickly as compared with a control method where an incremental rotation speed is added to a present rotation speed of the electric compressor, that is, 0 rpm. Accordingly, a large cooling capacity can be obtained for a short time period. Thus, an air temperature in a compartment can be quickly reduced to a comfortable temperature, when the air conditioner is started, for example.

Claims

1. An air conditioner, comprising:

a vapor compression refrigerant cycle including a compressor for compressing refrigerant, and an interior heat exchanger for adjusting a temperature of air to be blown into a compartment by performing heat exchange between refrigerant circulating in the vapor compression refrigerant cycle and the air to be blown into the compartment;

an actual capacity detecting means for detecting an actual capacity of the interior heat exchanger;

a target capacity determining means for determining a target capacity of the interior heat exchanger;

a first target rotation-speed determining means for determining a first control target rotation speed of the compressor based on a difference between the actual capacity detected by the actual capacity detecting means and the target capacity determined by the target capacity determining means;

a changing condition determining means for determining whether a rotation speed of the compressor needs to be changed by a change rate larger than a change rate of the first control target rotation speed, determined by the first target rotation-speed determining means; and

a second target rotation-speed determining means for determining a second control target rotation speed that is larger than the first control target rotation speed when the changing condition determining means determines that the rotation speed of the compressor needs to be changed by a change rate larger than the change rate of the first control target rotation speed.

2. The air conditioner according to claim 1, wherein

the changing condition determining means determines that the rotation speed of the compressor needs to be changed by a change rate larger than the change rate of the first control target rotation speed, when the compressor is started from a stop state.

3. The air conditioner according to claim 1, further comprising

a guard rotation speed determining means for determining a maximum permissible rotation speed of the compressor, wherein

the changing condition determining means determines that the rotation speed of the compressor needs to be changed by a change rate larger than the change rate of the first control target rotation speed determined by the first target rotation-speed determining means when the maximum permissible rotation speed determined by the guard rotation speed determining means increases and a difference between the control target rotation speed determined by the first target rotation-speed determining means and an actual rotation speed of the compressor is larger than a predetermined value.

4. The air conditioner according to claim 1, further comprising

a guard rotation speed determining means for determining a maximum permissible rotation speed of the compressor, wherein

the changing condition determining means determines that the rotation speed of the compressor needs to be changed at a change rate larger than the change rate of the first control target rotation speed determined by the first target rotation-speed determining means when the maximum permissible rotation speed determined by the guard rotation speed determining means increases and a difference between the actual capacity detected by the actual capacity detecting means and the target capacity determined by the target capacity determining means is larger than a predetermined value.

5. The air conditioner according to claim 4, wherein

the second target rotation-speed determining means determines the second control target rotation speed of the compressor based on a difference between the actual capacity detected by the actual capacity detecting means and the target capacity determined by the target capacity determining means.

6. The air conditioner according to claim 1, further comprising:

a guard rotation speed determining means for determining a maximum permissible rotation speed of the compressor;

an inside air temperature detecting means for detecting an air temperature inside the compartment; and

a temperature setting unit for setting a requested temperature in the compartment, wherein

the changing condition determining means determines that the rotation speed of the compressor needs to be changed by a change rate larger than the change rate of the second control target rotation speed determined by the first target rotation-speed determining means, when the maximum permissible rotation speed determined by the guard rotation speed determining means increases and a difference between the air temperature inside the passenger compartment, detected by the inside air temperature detecting means, and the requested temperature set by the temperature setting unit is larger than a predetermined value.

7. The air conditioner according to claim 6, wherein

the second target rotation-speed determining means determines the second control target rotation speed of the compressor based on a difference between the air temperature inside the passenger compartment, detected by the inside air temperature detecting means, and the requested temperature set by the temperature setting means.

8. The air conditioner according to claim 1, wherein

the second target rotation-speed determining means determines the second control target rotation speed of the compressor based on a target temperature of air blown into the compartment.

9. The air conditioner according to claim 1, wherein

the second target rotation-speed determining means determines the second control target rotation speed of the compressor by correcting the first control target rotation speed determined by the first target rotation-speed determining means.

10. The air conditioner according to claim 9, wherein

the second target rotation-speed determining means corrects the first control target rotation speed determined by the first target rotation-speed determining means based on an air conditioning load of the interior heat exchanger.

11. The air conditioner according to claim 1, wherein

the second target rotation-speed determining means determines the second control target rotation speed of the compressor based on the air conditioning load of the interior heat exchanger.

12. A control system for controlling an air conditioner, the air conditioner including a vapor compression refrigerant cycle having an interior heat exchanger for adjusting a temperature of air to be blown into a compartment by performing heat exchange between refrigerant circulating in the vapor compression refrigerant cycle and the air to be blown into the compartment, and a compressor for compressing refrigerant, the control system comprising:

an actual capacity detecting means for detecting an actual capacity of the interior heat exchanger;

a target capacity determining means for determining a target capacity of the interior heat exchanger;

a first target rotation-speed determining means for determining a first control target rotation speed of the compressor based on a difference between the actual capacity detected by the actual capacity detecting means and the target capacity determined by the target capacity determining means;

a changing condition determining means for determining whether a rotation speed of the compressor needs to be changed by a change rate larger than a change rate of the control target rotation speed, determined by the first target rotation-speed determining means; and

a second target rotation-speed determining means for determining a second control target rotation speed larger than the control target rotation speed determined by the first target rotation-speed determining means when the changing condition determining means determines that the rotation speed of the compressor needs to be changed by a change rate larger than the change rate of the first control target rotation speed.