System and method for extreme cold starting of a heating system
View Patent ↗A method and system are provided and include determining a sensed condition. When the sensed condition is below a first threshold and above a second threshold, the second threshold being less than the first threshold, a flow of coolant is started in a coolant loop comprising a first portion of a first heat exchanger. A flow of refrigerant is started in a refrigerant loop by starting a compressor within the refrigerant loop at a first speed.
1 . A method of operating a vehicle comprising:
determining a sensed condition at the vehicle;
when the sensed condition is below a first threshold and above a second threshold, the second threshold being less than the first threshold, starting a flow of coolant around a coolant loop comprising a first portion of a first heat exchanger and a heat mass of the vehicle; and
starting a flow of refrigerant around a refrigerant loop fluidically separated from the coolant loop by starting a compressor within the refrigerant loop at a first speed and circulating the refrigerant back to the compressor through the first heat exchanger.
2 . The method of claim 1 further comprising controlling a speed of the compressor based on the sensed condition.
3 . The method of claim 1 further comprising increasing a speed of the compressor above the first speed based on the sensed condition continuously increasing.
4 . The method of claim 1 further comprising increasing a speed of the compressor above the first speed based on a continuously increasing the sensed condition until a target speed is reached.
5 . The method of claim 1 further comprising increasing a speed of the compressor when the sensed condition meets a predetermined condition.
6 . The method of claim 1 wherein starting the flow of refrigerant is performed simultaneously with or after starting the flow of coolant.
7 . The method of claim 1 further comprising increasing a speed of the compressor when a refrigerant temperature is above a third threshold and the refrigerant temperature is increasing over a time period.
8 . The method of claim 1 wherein determining the sensed condition comprises determining the sensed condition at the refrigerant loop by determining at least one of: a temperature within the compressor, a temperature within a coolant conduit, a temperature within a refrigerant conduit, an ambient temperature, and a refrigerant pressure.
9 . The method of claim 1 further comprising raising a temperature of the coolant from a heat source to form heated coolant; and
heating refrigerant in the refrigerant loop at a first heat exchanger from the heated coolant.
10 . The method of claim 9 wherein raising the temperature of the coolant comprises at least one of raising the temperature of the coolant from a waste heat source, raising the temperature of the coolant from a coolant pump, raising the temperature of the coolant from a waste heat source and a coolant pump, and raising the temperature of the coolant from a battery housing and a coolant pump.
11 . A method comprising:
determining a refrigerant temperature;
when the refridgement temperature is below a first threshold and above a second threshold, the second threshold being less than the first threshold, starting a flow of coolant in a coolant loop comprising a first portion of a first heat exchanger; and
starting a flow of refrigerant in a refrigerant loop by starting a compressor within the refrigerant loop at a first speed; and
increasing a speed of the compressor when the refrigerant temperature is above a third threshold between the first threshold and the second threshold.
12 . A method comprising:
determining a sensed condition;
when the sensed condition is below a first threshold and above a second threshold, the second threshold being less than the first threshold, starting a flow of coolant in a coolant loop comprising a first portion of a first heat exchanger;
starting a flow of refrigerant in a refrigerant loop by starting a compressor within the refrigerant loop at a first speed;
communicating refrigerant from the compressor through a second heat exchanger; and
communicating coolant to the second heat exchanger in a second coolant loop fluidically coupled to the coolant loop.
13 . A system for a vehicle comprising:
a sensed condition sensor sensing a sensed condition at the vehicle;
a coolant loop comprising a first portion of a first heat exchanger and a heat mass of the vehicle;
a refrigerant loop comprising a compressor; and
a controller programmed to,
start a flow of coolant around the coolant loop when the sensed condition is below a first threshold and above a second threshold, the second threshold being less than the first threshold; and
start a flow of refrigerant around the refrigerant loop fluidically separated from the coolant loop by starting the compressor within the refrigerant loop at a first speed and circulating the refrigerant back to the compressor through the first heat exchanger.
14 . The system of claim 13 wherein the controller is programmed to increase a speed of the compressor above the first speed based on a continuously increasing sensed condition.
15 . The system of claim 13 wherein the controller is programmed to increase a speed of the compressor above the first speed based on a continuously increasing sensed condition until a target speed is reached.
16 . The system of claim 13 wherein the controller is programmed to increase a speed of the compressor when the sensed condition meets a predetermined condition.
17 . The system of claim 13 wherein the controller is programmed to increase a speed of the compressor when a refrigerant temperature is above a third threshold and the refrigerant temperature is increasing over a time period.
18 . The system of claim 13 wherein the sensed condition sensor comprises at least one of an ambient temperature sensor, a refrigerant pressure sensor, a compressor temperature sensor, a refrigerant conduit temperature sensor and a coolant conduit temperature sensor.
19 . The system of claim 13 further comprising a heat source fluidically coupled to the coolant forming heated coolant; and
a first heat exchanger heating refrigerant in the refrigerant loop from the heated coolant.
20 . A system comprising:
a sensed condition sensor sensing a refrigerant temperature;
a coolant loop comprising a first portion of a first heat exchanger;
a refrigerant loop comprising a compressor; and
a controller programmed to determine a sensed condition;
start a flow of coolant in when the sensed condition is below a first threshold and above a second threshold, the second threshold being less than the first threshold;
start a flow of refrigerant in the refrigerant loop by starting the compressor within the refrigerant loop at a first speed; and
increase a speed of the compressor when the refrigerant temperature is above a third threshold between the first threshold and the second threshold.