Automatic control method used for defrosting a heat pump for a vehicle
First Claim
1. A control method for a heat pump system for a motor vehicle, the system including a compressor for heating and compressing a refrigerant fluid, an internal heat exchanger forming a condenser in a heating mode for heating internal air by exchange with the refrigerant fluid flowing from the compressor, an expansion valve for cooling the refrigerant fluid, an external heat exchanger forming an evaporator in the heating mode for heating the refrigerant liquid flowing from the expansion valve by exchange with external air, and an accumulator interposed between the external heat exchanger and the compressor for storing the refrigerant fluid before compression, the method comprising:
- a) in the heating mode, detecting frosting of the external heat exchanger;
b) determining a data element representing a duration of the frosting of the heat exchanger;
c) if the duration of the frosting of the external heat exchanger is greater than or equal to a first predetermined maximum duration, sending a command for defrosting the external heat exchanger; and
d) if a command for defrosting the external heat exchanger is sent, starting an operation of defrosting the external heat exchanger and, according to a predefined criterion, starting an operation of defrosting the accumulator by circulating a fluid compressed by the compressor in the external heat exchanger and the accumulator,wherein, in operation a), frosting of the external heat exchanger is detected if the external air temperature is below a second predetermined temperature value and the temperature difference between the external air temperature and the temperature of the refrigerant fluid at an outlet of the external heat exchanger is above a third predetermined temperature value.
1 Assignment
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Accused Products
Abstract
A control method for a heat pump system, or for a motor vehicle, which includes a compressor, an internal heat exchanger forming a condenser in a heating mode, an expansion valve, an outer heat exchanger forming an evaporator in the heating mode, and an accumulator. The defrosting of the outer exchanger is detected, the defrosting of the accumulator is detected, and depending on the case, defrosting the outer exchanger and/or defrosting the accumulator is started.
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Citations
17 Claims
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1. A control method for a heat pump system for a motor vehicle, the system including a compressor for heating and compressing a refrigerant fluid, an internal heat exchanger forming a condenser in a heating mode for heating internal air by exchange with the refrigerant fluid flowing from the compressor, an expansion valve for cooling the refrigerant fluid, an external heat exchanger forming an evaporator in the heating mode for heating the refrigerant liquid flowing from the expansion valve by exchange with external air, and an accumulator interposed between the external heat exchanger and the compressor for storing the refrigerant fluid before compression, the method comprising:
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a) in the heating mode, detecting frosting of the external heat exchanger; b) determining a data element representing a duration of the frosting of the heat exchanger; c) if the duration of the frosting of the external heat exchanger is greater than or equal to a first predetermined maximum duration, sending a command for defrosting the external heat exchanger; and d) if a command for defrosting the external heat exchanger is sent, starting an operation of defrosting the external heat exchanger and, according to a predefined criterion, starting an operation of defrosting the accumulator by circulating a fluid compressed by the compressor in the external heat exchanger and the accumulator, wherein, in operation a), frosting of the external heat exchanger is detected if the external air temperature is below a second predetermined temperature value and the temperature difference between the external air temperature and the temperature of the refrigerant fluid at an outlet of the external heat exchanger is above a third predetermined temperature value. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A control method for a heat pump system for a motor vehicle, the system including a compressor for heating and compressing a refrigerant fluid, an internal heat exchanger forming a condenser in a heating mode for heating internal air by exchange with the refrigerant fluid flowing from the compressor, an expansion valve for cooling the refrigerant fluid, an external heat exchanger forming an evaporator in the heating mode for heating the refrigerant liquid flowing from the expansion valve by exchange with external air, and an accumulator interposed between the external heat exchanger and the compressor for storing the refrigerant fluid before compression, the method comprising:
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a) in the heating mode, detecting frosting of the external heat exchanger; b) determining a data element representing a duration of the frosting of the heat exchanger; c) if the duration of the frosting of the external heat exchanger is greater than or equal to a first predetermined maximum duration, sending a command for defrosting the external heat exchanger; and d) if a command for defrosting the external heat exchanger is sent, starting an operation of defrosting the external heat exchanger and, according to a predefined criterion, starting an operation of defrosting the accumulator by circulating a fluid compressed by the compressor in the external heat exchanger and the accumulator, wherein; operation a) further comprises detecting the frosting of the accumulator; operation b) further comprises determining a data element representing the duration of the frosting of the accumulator; and operation c) further comprises sending a command for defrosting the accumulator if the duration of the frosting of the external heat accumulator is greater than or equal to a second predetermined maximum duration; wherein an operation of defrosting the accumulator is started if a command for defrosting the accumulator is sent; and wherein, during operation b), a first counter is incremented when the frosting of the external heat exchanger is detected, and a second counter is incremented when the frosting of the accumulator is detected. - View Dependent Claims (8, 9, 10, 11, 12, 13)
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14. A control method for a heat pump system for a motor vehicle, the system including a compressor for heating and compressing a refrigerant fluid, an internal heat exchanger forming a condenser in a heating mode for heating internal air by exchange with the refrigerant fluid flowing from the compressor, an expansion valve for cooling the refrigerant fluid, an external heat exchanger forming an evaporator in the heating mode for heating the refrigerant liquid flowing from the expansion valve by exchange with external air, and an accumulator interposed between the external heat exchanger and the compressor for storing the refrigerant fluid before compression, the method comprising:
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a) in the heating mode, detecting frosting of the external heat exchanger; b) determining a data element representing a duration of the frosting of the heat exchanger; c) if the duration of the frosting of the external heat exchanger is greater than or equal to a first predetermined maximum duration, sending a command for defrosting the external heat exchanger; and d) if a command for defrosting the external heat exchanger is sent, starting an operation of defrosting the external heat exchanger and, according to a predefined criterion, starting an operation of defrosting the accumulator by circulating a fluid compressed by the compressor in the external heat exchanger and the accumulator, wherein the operation of defrosting the external heat exchanger comprises putting the compressor into operation at a first predetermined motor speed, to cause hot refrigerant fluid to flow in the external heat exchanger and the accumulator for a duration which is less than or equal to a third predetermined maximum duration, the motor speed and the third maximum duration being a function of the defrosting operation, wherein the putting the compressor into operation at a first motor speed for a duration which is less than or equal to a third maximum duration comprises; putting the compressor into operation at the first motor speed; incrementing a third counter, as long as the temperature of the refrigerant fluid at an outlet of the external heat exchanger is less than or equal to a seventh predetermined temperature value and as long as a count value of the third counter is less than a third predetermined count value representing a fifth maximum duration which is less than the third maximum duration, and as long as an external temperature is less than or equal to an eighth predetermined temperature; and stopping the compressor when the incrementing of the third counter is stopped. - View Dependent Claims (15, 16, 17)
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Specification