Patent Grant
9890756
This application claims foreign priority benefits under 35 U.S.C. § 119(a)-(d) to European patent application number EP 13193124.8, filed Nov. 15, 2013 which is incorporated by reference in its entirety.
The present disclosure relates to a heating and cooling system for an internal combustion engine and a method of controlling such a system.
Today, there exist differently configured and types of cooling systems for internal combustion engines in vehicles comprising heat storage accumulators or containers to be utilized for warm-up of the engine after an engine stop. Such heat storage containers are used by being charged with hot coolant during engine running, which containers then are emptied by discharging and circulating the stored hot coolant in the engine during start-up for warming up the engine.
One example of such a heat storage system is disclosed in US 2010/0186685 A1.
However, the constant increasing demand on lowering unwanted exhaust emission and fuel consumption characteristics of internal combustion engines at cold start has revealed that warm-up of the engine after an engine stop is still not satisfactory by using prior art heat storage systems.
One object of the present disclosure is to overcome at least some of the problems and drawbacks mentioned above.
These and further objects are achieved by a heating and cooling system for an internal combustion engine comprising a heat storage circuit and a radiator circuit, wherein the heat storage circuit comprises a heat storage container, in which engine coolant is stored and allowed to flow into and out of, which heat storage container has a container inlet connected, e.g., via a container conduit, to a first coolant outlet of the engine and a container outlet connected, e.g., via a container conduit, to a first coolant inlet of the engine. The radiator circuit comprises a radiator for flow of the engine coolant and the radiator has an radiator inlet and an radiator outlet, the radiator inlet being connected, e.g., via an upstream radiator conduit, to a second coolant outlet of the engine and the radiator outlet being connected, e.g., via a downstream radiator conduit, to a second coolant inlet of the engine. A bypass conduit is connected between the upstream radiator conduit and the downstream radiator conduit and adapted to allow coolant to bypass the radiator; and a thermostat controlled valve arranged in the upstream radiator conduit at the second coolant outlet and connected to the bypass conduit, which thermostat controlled valve is adapted to direct coolant flow to the radiator and/or to the bypass conduit, wherein a shut-off valve is arranged in the bypass conduit.
These and further objects are also achieved by a method of controlling the heating and cooling system above comprising a heat storage circuit and a radiator circuit, which heat storage circuit comprises a heat storage container storing engine coolant and allowing coolant to flow into and out of, and which heat storage container has a container inlet connected, e.g., via a container conduit, to a first coolant outlet of the engine and a container outlet connected, e.g., via a container conduit, to a first coolant inlet of the engine. The radiator circuit comprises a radiator for flow of the engine coolant and the radiator has an radiator inlet and an radiator outlet, the radiator inlet being connected, e.g., via an upstream radiator conduit, to a second coolant outlet of the engine and the radiator outlet being connected, e.g., via a downstream radiator conduit, to a second coolant inlet of the engine. A bypass conduit is connected between the upstream radiator conduit and the downstream radiator conduit allowing coolant to bypass the radiator; and a thermostat controlled valve is arranged in the upstream radiator conduit at the second coolant outlet and connected to the bypass conduit, which thermostat controlled valve directs coolant flow to the radiator and/or to the bypass conduit, by a shut-off valve being arranged in the bypass conduit for controlling any engine coolant flow through the bypass conduit and the thermostat controlled valve.
In some embodiments, the shut-off valve is adapted to cut off any engine coolant flow through the bypass conduit until the heat storage container is recharged with engine coolant of a predetermined temperature.
In some embodiments, the shut-off valve is adapted to open for engine coolant flow through the bypass conduit such that the thermostat controlled valve is opened when the engine coolant has a temperature being equal to or greater than a predetermined temperature.
In some embodiments, the shut-off valve is adapted to cut off any engine coolant flow through the bypass conduit until the predetermined charge temperature of the heat storage container is reached, this temperature being higher than the opening temperature of the thermostat controlled valve.
In some embodiments, the shut-off valve is adapted to cut off any engine coolant flow through the bypass conduit until the predetermined charge (or target) temperature of the heat storage container is stable/reached.
In some embodiments, an intermediate conduit is connected between the heat storage circuit and the radiator circuit and a second shut-off valve is arranged in the intermediate conduit.
In some embodiments, the second shut-off valve is adapted to cut off any engine coolant flow from an oil cooler of the engine to the radiator circuit until the heat storage container is recharged with engine coolant of a predetermined temperature being higher than the opening temperature of the thermostat controlled valve.
In some embodiments, the second shut-off valve is adapted to cut off any engine coolant flow from an oil cooler of the engine to the radiator circuit until the engine coolant has a temperature being equal to or greater than the predetermined temperature.
In some embodiments, a method of controlling a heating and cooling system is achieved by the shut-off valve cutting off any engine coolant flow through the bypass conduit until the heat storage container is recharged with engine coolant of a predetermined temperature being higher than the opening temperature of the thermostat controlled valve.
In some embodiments, the method of controlling a heating and cooling system is achieved by the shut-off valve opening for engine coolant flow through the bypass conduit, such that the thermostat controlled valve opens, when the engine coolant has reached a temperature being equal to or greater than the opening temperature of the thermostat controlled valve.
In some embodiments, the method of controlling a heating and cooling system is achieved by the shut-off valve cutting off any engine coolant flow through the bypass conduit until the predetermined charge temperature of the heat storage container is reached, this temperature being higher than the opening temperature of the thermostat controlled valve.
The effects and advantages of the above system; the method of controlling said system, and the embodiments are the following. It is possible to reach a significantly higher temperature for charging a thermos, i.e., a heat storage container, this temperature being higher than the opening temperature of the thermostat controlled valve, by preventing the hot coolant to reach the thermostat in the radiator system by restricting the flow in the thermostat area, i.e., around the thermostat during start- and warm-up of the engine. According to the disclosure, the shut-off valve cuts off any engine coolant flow through the bypass conduit until at least a control valve for the heat storage container is closed. After this closure, i.e., stopping the flow of hot coolant into and out of the hot storage container, after having reached a predetermined temperature in the heat storage container being higher than the opening temperature of the thermostat controlled valve, it is possible to store more heat energy into a specific volume/weight of a heat storage container than hitherto possible, and to improve the time from the container, i.e., thermos charge until heat is no longer available, typically 24 hours prolongation compared to prior art systems.
According to the disclosure, the idea is to use a heat storage container in the system, and get the most energy out of the space occupied by the container as packaging space is scarce in today's modern vehicles, i.e., the size of any heat storage container is impossible to increase, at least not to a large extent or in a more cost efficient way. Hence, when charging a heat storage container in the inventive cooling system we can get the highest possible temperature of the coolant into the container before the thermostat opens for coolant flow into the larger radiator system of the vehicle. The inventors realized, as the size of the coolant storage container or thermos is in principle fixed, that the temperature in the coolant storage thermos determines the amount of stored energy, the higher the temperature, the higher the amount of stored heat to improve emissions and fuel consumption at the next engine start.
Existing systems charge a heat storage container, i.e., the coolant storage thermos, at a temperature lower than thermostat opening temperature, typically 85° C. (if thermostat opening starts at 90° C.). By increasing the charge temperature into the heat storage container to above, i.e., higher than the opening temperature of the thermostat controlled valve according to the disclosure, the stored energy is increased from, one example is (85−20=ΔT, degree Celsius/Kelvin)*(times) m (mass, kg)*(times) cp (specific heat capacity, J/kg*K) to (110−20=ΔT)*m*cp if the ambient temperature is about 20° C., meaning an improvement of almost 40% and higher using the same weight and volume for the container. This also leads to reduced fuel consumption, less exhaust emissions, specifically Hydrocarbons (HC) and carbon monoxides (CO) for diesel engines.
The disclosure will be described in more detail with reference to the accompanying drawings.
As required, detailed embodiments are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary and that various and alternative forms may be employed. The figures are not necessarily to scale. Some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art.
As described above and shown in
The heating and cooling system 1 comprises the inventive heat storage circuit 3 and the large radiator circuit 4. The heat storage circuit 3 comprises a heat storage container 30, in which engine coolant is stored and allowed to flow into and out of. The heat storage container 30 has a container inlet 31 connected via a container conduit 32 to a first coolant outlet 21 of the engine and a container outlet 33 connected via a container conduit 34 to a first coolant inlet 22 of the engine. The radiator circuit 4 comprises a radiator 40 for flow of the engine coolant and the radiator has a radiator inlet 41 and a radiator outlet 42. The radiator inlet 41 is connected via an upstream radiator conduit 43 to a second coolant outlet 23 of the engine 2. The radiator outlet 42 is connected via a downstream radiator conduit 44 to a second coolant inlet 24 of the engine 2.
The heating and cooling system 1 comprises a bypass conduit 45 connected between the upstream radiator conduit 43 and the downstream radiator conduit 44. This bypass conduit 45 is adapted to allow coolant to bypass the radiator 40. A thermostat controlled valve 46 is arranged in the upstream radiator conduit 43 at the second coolant outlet 23. The thermostat controlled valve 46 is connected to the bypass conduit 45. The thermostat controlled valve 46 is adapted to direct coolant flow to the radiator 40 and/or to the bypass conduit. According to the disclosure, a shut-off valve 47 is arranged in the bypass conduit 45.
The heating and cooling system 1 may comprise an electric vacuum switch system 9 for control of the shut-off valve 47 (V1) and the control lines are shown dashed with arrows but only represent electrical signal lines and not any flow path for the coolant. This is a known way of control and will not be explained in further detail.
The heating and cooling system 1 may comprise a degas system comprising an expansion tank for compensation of volume change of the coolant and associated equipment, such as conduits and valves for letting out and guiding back any steam from the coolant into the system 1 in a known way and will not be explained in further detail.
The engine 2 as shown in
The heat storage circuit 3 is adapted to separately from the radiator circuit 4 circulate coolant for a quicker warm-up of the engine 2 after a stop of the engine according to the disclosure. In principle, the heat storage circuit 3 circulates a lesser amount/volume of coolant compared to the radiator circuit 4, but as the temperature for the coolant stored in the heat storage container 30 is higher than any opening temperature of the thermostat controlled valve 46, this temperature is high enough for achieving a quicker warm-up of the engine compared to prior art even though the size of the heat storage container in fact is not increased, i.e., at least not increased substantially in size, according to the disclosure. In any case, when the flow in the radiator circuit 4 is initiated, started or ongoing as shown in
In one embodiment, the heat storage container 30 has its container inlet 31 connected via a container conduit 32 to one of two outlet ports of a three-way valve 35 (V3, see
The first coolant outlet 21 of the engine 2 may let coolant flow out of an engine oil cooler 20 (EOC) if the vehicle is equipped with such an EOC, e.g., if the vehicle uses an automatic transmission that must be cooled during performance driving conditions. Coolant flow, in general, is substantially a function of water pump speed.
The heat storage circuit 3 and coolant flow through it is controlled and achieved by means of a first electrical coolant pump 6 (see upper part of
The second coolant inlet 24 of the engine 2 is placed at the opposite side of the engine compared to the first engine coolant outlet 21 and the second engine coolant outlet 23. The bypass conduit 45 is connected between the upstream radiator conduit 43 and the downstream radiator conduit 44. The thermostat controlled valve 46 is connected to the bypass conduit 45.
Hence, the shut-off valve 47 is adapted to cut off any engine coolant flow through the thermostat controlled valve 46. This is done by means of the shut-off valve 47 being arranged in the bypass conduit 45 enabling that no engine coolant is able to flow past or be in any heating contact with the thermostat controlled valve 46, such that the heat of the engine coolant is not transferred to the thermostat controlled valve 46. Hence, the thermostat controlled valve 46 is not opened and does not let any engine coolant flow through the radiator when the bypass conduit 45 is closed off by the shut-off valve 47 according to the disclosure.
The thermostat controlled valve 46 opens when the temperature of the coolant is equal to and/or higher than its opening temperature by means of wax expanding at a heat sensing portion of the thermostat 46. According to the disclosure, by placing the shut-off valve 47 in the bypass conduit 45, this shut-off valve 47 is used to control how much heat the heat sensing portion of the thermostat controlled valve 46 is exposed to by controlling how much flow of hot coolant that is let through the bypass conduit 45. This control is enabled as such an arrangement of the shutoff valve 47 directly controls the amount of hot coolant through a thermostat housing of the thermostat controlled valve 46. No flow of hot coolant through the bypass conduit and the thermostat housing of the thermostat controlled valve 46 by shutting off bypass conduit 45 completely by shut-off valve 47, means that substantially no heat is transferred to the heat sensing portion of the thermostat controlled valve 46 and no expansion of wax occurs and hence no opening of the thermostat controlled valve is achieved. A small or larger amount of flow of hot coolant let through the bypass conduit 45 and the thermostat housing of the thermostat controlled valve 46 by only opening the shutoff valve 47 somewhat or partly, means that more or less heat is transferred to the heat sensing portion of the thermostat controlled valve 46 and expansion of wax occurs for opening the thermostat controlled valve. This control is done to achieve as high a coolant temperature as possible for use as the highest possible charging temperature of the heat storage container 30 before the larger radiator circuit 4 and its “normal” cooling of coolant is required and initiated.
The shut-off valve 47 cuts off any engine coolant flow through the bypass conduit 45 until the heat storage container 30 is recharged with engine coolant of a predetermined temperature. In another embodiment, the shut-off valve 47 opens for engine coolant flow through the bypass conduit 45, so that the thermostat controlled valve 46 is opened, when the engine coolant has a temperature being equal to or greater than a predetermined temperature, this temperature being higher than the opening temperature of the thermostat controlled valve 46.
The shut-off valve 47 cuts off any engine coolant flow through the bypass conduit 45 until at least the control valve 35 for the heat storage container 30 is closed. This closure ends the hot coolant flow into and out of the heat storage container 30 (see
The heating and cooling system 1 may also comprise an intermediate conduit connected between the heat storage circuit 3 and the radiator circuit 4. A second shut-off valve may be arranged in the intermediate conduit between the engine oil cooler 20 and the downstream radiator conduit 44 in the Figures.
An inventive control of the heating and cooling system 1 comprising the heat storage circuit 3 and the radiator circuit 4 is achieved. This inventive method is realized by arranging the shut-off valve 47 in the bypass conduit 45 for controlling any engine coolant flow through the bypass conduit 45 and the thermostat controlled valve 46 before the large coolant flow through the radiator circuit 4 is initiated.
If the ambient temperature outside and/or within the vehicle is high, e.g., above 20° C., during warm-up of the engine 2, cabin heating is not requested from start of engine warm-up and the following exemplifying procedures are done for control of the warm-up of the engine 2 without using the cabin heater 7 of the vehicle.
A first condition is discharge of hot coolant from the heat storage container 30 for warm-up of the engine 2. The engine 2 is started with coolant temperature less than 60° C. (<60° C.) and the third gear of the vehicle transmission may be in operation to avoid involuntary start if only short parking maneuvers are performed.
The following control actions are performed:
1. shut-off valve 47 is closed.
2. first three-way valve 35 is activated to allow coolant flow through the heat storage container.
3. first electrical coolant pump 6 is started.
A second condition is when coolant temperature into the heat storage container 30 is higher than the temperature in the heat storage container or out from the heat storage container (temperature into heat storage container>temperature in heat storage container/out from heat storage container). These temperatures are measured or modeled.
The following control actions are performed:
1. shut-off valve 47 is still closed.
2. first three-way valve 35 is activated to bypass flow through the heat storage container 30.
3. first electrical coolant pump 6 is stopped.
A third condition is when recharge of the heat storage container 30 is performed, i.e., when target coolant temperature for recharge is reached.
The following control actions are performed:
1. shut-off valve 47 is still closed.
2. first three-way valve 35 is activated to allow coolant flow through heat storage container 30.
3. first electrical coolant pump 6 is started.
A fourth condition is a thermostat control when target coolant temperature is reached again after recharge of the heat storage container 30.
The following control actions are performed:
1. first three-way valve 35 is activated to stop flow through the heat storage container.
2. first electrical coolant pump 6 is stopped.
3. shut-off valve 47 is opened, and the thermostat controlled valve 46 is flushed with hot coolant to start opening to provide cooling of coolant through the radiator circuit 4 during “normal” operation of the engine.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 13193124 | Nov 2013 | EP | regional |
| Number | Name | Date | Kind |
|---|---|---|---|
| 7216697 | Odeskog et al. | May 2007 | B2 |
| 20060231640 | Hashimura | Oct 2006 | A1 |
| 20080216777 | Vetrovec | Sep 2008 | A1 |
| 20100186685 | Hiyama | Jul 2010 | A1 |
| 20140097261 | Blumenstock | Apr 2014 | A1 |
| Number | Date | Country |
|---|---|---|
| 102011050200 | Nov 2012 | DE |
| 2843168 | Feb 2004 | FR |
| 10159564 | Jun 1998 | JP |
| 2000073764 | Mar 2000 | JP |
| 2003184556 | Jul 2003 | JP |
| 2004301063 | Oct 2004 | JP |
| Entry |
|---|
| Extended European Search Report dated Mar. 18, 2014, Application No. 13193124.8-1603, Applicant Volvo Car Corporation, 7 Pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20150136048 A1 | May 2015 | US |
