Refrigerant charge diagnostic procedure for vehicle heat pump systems
AssigneeFord Global Technologies, LLC
InventorScott Thomas Vehige
Life of this patent
Estimating the term…
Abstract
A diagnostic for heat pumps may include causing heated coolant in a coolant loop to circulate through a heat exchanger that is thermally coupled to a refrigerant loop. The temperature and pressure of the refrigerant may be measured while the heated coolant is circulated through the heat exchanger, and the measured pressure and temperature may be compared to pressures and temperatures for systems that are properly charged with refrigerant to determine if the heat pump system is properly charged.
Claims20
A method of determining refrigerant charge in vehicle heat pump systems having a heat exchanger that thermally couples a coolant loop to a refrigerant loop;
- the method comprising:
- heating and circulating coolant through the coolant loop and through the heat exchanger of the vehicle heat pump system while refrigerant is not circulating through the refrigerant loop of the heat pump system;
- measuring temperature and pressure of refrigerant in the refrigerant loop while heating and circulating the coolant through the coolant loop and through the heat exchanger;
- and
- comparing measured temperature and pressure of the refrigerant to expected temperature and pressure to determine if the refrigerant charge satisfies predefined charge criteria.
A vehicle comprising:
- a powered drive system;
- a body;
- a heat pump system that is configured to heat a cabin of the vehicle, the heat pump system including a first heat exchanger that thermally couples a coolant loop of the heat pump system to a refrigerant loop of the heat pump system, the coolant loop including a coolant heater and a pump that are fluidly coupled to the first heat exchanger and a thermal load of the vehicle, the refrigerant loop including a compressor that is fluidly coupled to the first heat exchanger, an expansion valve, and an outside heat exchanger;
- a controller configured to:
- actuate the coolant heater and the pump to cause coolant to circulate through the coolant loop and through the first heat exchanger of the vehicle heat pump system prior to operation of the refrigerant loop of the heat pump system;
- and
- compare temperature and pressure of the refrigerant measured while the coolant is being heated and circulated through the coolant loop and through the first heat exchanger to expected refrigerant temperature and pressure for a fully charged heat pump system to determine if the refrigerant charge satisfies predefined charge criteria.
A method of diagnosing refrigerant charge of a vehicle heat pump system having a heat exchanger that thermally couples a coolant loop to a refrigerant loop;
- the method comprising:
- heating and circulating coolant through the coolant loop and through the heat exchanger of the vehicle heat pump system while a compressor of the refrigerant loop is deactivated;
- measuring changes in temperature and pressure of the refrigerant that result from heating and circulating the coolant through the coolant loop;
- and
- comparing the changes in the measured temperature and pressure of the refrigerant to expected changes in temperature and pressure to determine if the heat pump system is properly charged with refrigerant.
Dependencies are inferred from the claim text.