Automated no-idle heating and engine pre-heat using engine coolant
View Patent ↗To avoid engine idling to support cabin heating, an auxiliary coolant heater can heat engine coolant and pump it through compartment heaters or the engine cooling system. The coolant flow control system provides great flexibility in selectively distributing heated coolant for heating and engine preheating.
1. A motor vehicle comprising:
an internal combustion engine;
an engine cooling system for the internal combustion engine including a pump for circulating coolant through the internal combustion engine;
an auxiliary coolant heater including an auxiliary pump;
a passenger cabin;
a primary heat exchanger having an inlet port and an outlet port, the primary heat exchanger being installed with respect to the passenger cabin to release heat into the passenger cabin;
an auxiliary heat exchanger having an inlet port and an outlet port, the auxiliary heat exchanger being installed with respect to the passenger cabin to release heat into the passenger cabin;
a coolant circulating circuit including the engine cooling system, the auxiliary coolant heater, and connected by the respective inlet and outlet ports to the primary heat exchanger and the auxiliary heat exchanger;
the coolant circulating circuit further including an engine cooling system outlet control valve, a primary heat exchanger flow control valve, an auxiliary heat exchanger flow control valve and an auxiliary heater flow control valve, the engine cooling system outlet control valve providing for selectively isolating the engine cooling system within and interconnecting the engine cooling system to the coolant circulating circuit, and the primary heat exchanger flow control valve, the auxiliary heat exchanger flow control valve and the auxiliary heater flow control valve providing for cutting off and allowing the flow of coolant through the primary heat exchanger, the auxiliary heat exchanger and the auxiliary heater, respectively;
the engine cooling system operating when interconnected to the coolant circulating circuit for delivering coolant to the primary heat exchanger flow control valve and the auxiliary heat exchanger flow control valve for allowing flow through the heat exchangers by way of the inlet ports to the outlet ports;
the auxiliary pump being connected to the coolant circulating circuit and operable for pumping coolant to deliver coolant to the primary heat exchanger or the auxiliary heat exchanger at the respective outlet ports for reverse flow through the heat exchangers to the inlet ports;
a climate controller coupled to open, close and modulate the engine cooling system outlet control valve, the primary heat exchanger flow control valve, the auxiliary heat exchanger flow control valve and the auxiliary heater flow control valve in response to selection of one of a plurality of operating states; and
the plurality of operating states including a first state where the auxiliary heater is on with the auxiliary pump running and the internal combustion engine is off to circulate coolant through the engine cooling system, a second state where the engine is off and the auxiliary heater is on to circulate coolant through either or both of the primary and auxiliary heat exchangers, a third state where the internal combustion engine and the auxiliary heater are concurrently running and in which the engine cooling system outlet control valve is closed to isolate the engine cooling system, and a fourth state where the internal combustion engine is on and the auxiliary heater is off.
2. A motor vehicle in accord with claim 1 , further comprising:
input sources connected for communication to the climate controller indicating engine operational state and coolant temperature;
operator inputs connected for communication to the climate controller for selecting cabin heating functions including defrosting; and
the climate controller being responsive to the input sources and the operator inputs for determining the operating state of the coolant circulation circuit and being further responsive to the determined operating state for selecting opened and closed states for each of the engine cooling system outlet control valve, the primary heat exchanger flow control valve, the auxiliary heat exchanger flow control valve and the auxiliary heater flow control valve.
3. A motor vehicle in accord with claim 2 , further comprising:
in the first state opening the engine cooling system outlet control valve to allow coolant flow through the engine cooling system, closing the primary heat exchanger flow control valve, closing the auxiliary heat exchanger flow control valve and opening the auxiliary heater flow control valve.
4. A motor vehicle in accord with claim 2 , further comprising:
in the second state modulating the engine cooling system outlet control valve to periodically allow coolant flow through the engine cooling system, closing the primary heat exchanger flow control valve, opening the auxiliary heat exchanger flow control valve and opening the auxiliary heater flow control valve for reverse flow of coolant through the primary and auxiliary heat exchangers.
5. A motor vehicle in accord with claim 2 , further comprising:
in the third state closing the engine cooling system outlet control valve and isolating the engine cooling system, opening or modulating the primary heat exchanger flow control valve for reverse flow, opening or modulating the auxiliary heat exchanger flow control valve for reverse flow of coolant through the primary and auxiliary heat exchangers and opening the auxiliary heater flow control valve.
6. A motor vehicle in accord with claim 2 , further comprising:
in the fourth state opening the engine cooling system outlet control valve to allow coolant flow through the engine cooling system, opening or modulating the primary heat exchanger flow control valve, opening or modulating the auxiliary heat exchanger flow control valve and closing the auxiliary heater flow control valve.
7. A coolant circulation circuit for climate control and preheat comprising:
coolant for circulating;
a primary heat source for coolant having a primary pump and an internal coolant circulation subcircuit;
an auxiliary coolant heater including an auxiliary pump;
a primary heat exchanger for sinking heat from circulating coolant;
an auxiliary heat exchanger for sinking heat from the circulating coolant;
connections between the internal coolant circulation sub-circuit and the primary heat exchanger, the auxiliary heat exchanger and the auxiliary coolant heater;
an outlet control valve for the internal coolant circulation sub-circuit, a primary heat exchanger flow control valve, an auxiliary heat exchanger flow control valve and an auxiliary heater flow control valve, the outlet control valve allowing for isolation of the internal coolant circulation sub-circuit;
the primary heat exchanger flow control valve, the auxiliary heat exchanger flow control valve and the auxiliary heater flow control valve providing for cutting off and allowing the flow of coolant through any one or more of the primary heat exchanger, the auxiliary heat exchanger or the auxiliary heater, respectively;
a controller coupled to open, close and modulate the outlet control valve, the primary heat exchanger flow control valve, the auxiliary heat exchanger flow control valve and the auxiliary heater flow control valve to control flow through the primary heat exchanger and auxiliary heat exchanger including control over the direction of flow of circulating coolant through the primary heat exchanger and the auxiliary heat exchanger in response to selection of one of a plurality of operating states; and
the plurality of operating states including a first state where the auxiliary heater is running and the primary heat source is off, a second state where the primary heat source is off and the auxiliary heater is on, a third state where the primary heat source and the auxiliary heater are concurrently on, and a fourth state in which the primary heat source is on and the auxiliary heater is off.
8. A coolant circulation circuit in accord with claim 7 , further comprising:
input sources connected for communication to the controller indicating a primary pump operational state and coolant temperature;
operator inputs connected for communication to the controller for selecting among the primary and auxiliary heat exchangers for operation; and
the controller being responsive to the input sources and the operator inputs for determining the operating state of the coolant circulation circuit and being further responsive to the determined operating state for selecting opened and closed states for each of the outlet control valve, the primary heat exchanger flow control valve, the auxiliary heat exchanger flow control valve and the auxiliary heater flow control valve.
9. A coolant circulation circuit in accord with claim 8 , further comprising:
in the first state opening the outlet control valve, closing the primary heat exchanger flow control valve, closing the auxiliary heat exchanger flow control valve and opening the auxiliary heater flow control valve.
10. A coolant circulation circuit in accord with claim 8 , further comprising:
in the second state modulating the outlet control valve, closing the primary heat exchanger flow control valve, opening the auxiliary heat exchanger flow control valve and opening the auxiliary heater flow control valve with reversal of flow of the circulating coolant.
11. A coolant circulation circuit accord with claim 8 , further comprising:
in the third state closing the outlet control valve and isolating the engine cooling system, opening or modulating the primary heat exchanger flow control valve for reverse flow, opening or modulating the auxiliary heat exchanger flow control valve for reverse flow of the circulating coolant and opening the auxiliary heater flow control valve.
12. A motor vehicle in accord with claim 8 , further comprising:
in the fourth state opening the outlet control valve to allow circulating coolant flow through the engine cooling system, opening or modulating the primary hear exchanger flow control valve, opening or modulating the auxiliary heat exchanger flow control valve and closing the auxiliary heater flow control valve.