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 includes heating refrigerant in a refrigerant loop of the heat pump. The temperature and pressure of the heated refrigerant may be measured, 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 having an electrically powered compressor motor that drives a compressor pump, the method comprising:
- heating refrigerant in the refrigerant loop of the heat pump system;
- measuring temperature and pressure of heated refrigerant in the refrigerant loop;
- and
- comparing measured temperature and pressure of the heated 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 refrigerant loop including a compressor that is fluidly coupled to the first heat exchanger, an expansion valve, and an outside heat exchanger, wherein the compressor includes an electrically powered compressor motor that drives a compressor pump;
- a controller configured to:
- actuate a heater to heat refrigerant and/or cause electrical power to be supplied to the compressor motor in a manner that causes the compressor motor to generate heat and heat refrigerant without rotation of the compressor pump;
- and
- compare measured temperature and pressure of the heated refrigerant 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 refrigerant in the refrigerant loop while a pump of a compressor of the refrigerant loop is not rotating;
- measuring changes in temperature and pressure of the refrigerant that result from heating the refrigerant;
- 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.