Engine system

• US 10,655,529 B2
• Filed: 11/21/2017
• Issued: 05/19/2020
• Est. Priority Date: 12/26/2016
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Kakuta, Yushi
• Primary Examiner(s): Trieu, Thai Ba
• Application Number:
  US15/819,546
• Publication Number:
  US 20180179946A1
• Time in Patent Office: 910 Days
• Field of Search: 60599, 606052, 123 4102, 123 4108, 123 411, 123 4112
• CPC Class Codes: F01P 2003/182 with multiple heat-exchangers
• CPC Class Codes: F01P 2005/105 Using two or more pumps
• CPC Class Codes: F01P 2007/146 using valves
• CPC Class Codes: F01P 2060/02 Intercooler
• CPC Class Codes: F01P 2060/12 Turbo charger
• CPC Class Codes: F01P 5/10 Pumping liquid coolant; Arrangements of coolant pumps
• CPC Class Codes: F01P 7/16 by thermostatic control
• CPC Class Codes: F01P 7/167 by adjusting the pre-set temperature according to engine parameters, e.g. engine load, engine speed
• CPC Class Codes: F02B 29/0443 Layout of the coolant or refrigerant circuit
• CPC Class Codes: F02M 26/06 Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor
• CPC Class Codes: F02M 26/21 with EGR valves located at or near the connection to the intake system
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An engine system includes an internal combustion engine, a compressor, a high-temperature coolant circulation circuit, a low-temperature coolant circulation circuit, an intercooler, and an electronic control unit. The intercooler is configured to transfer heat of the high-temperature coolant to the low-temperature coolant via intake air. An in-compressor passage of the compressor is arranged in the low-temperature coolant circulation circuit at a location at which the low-temperature coolant that exits from an in-cooler low-temperature water passage during a predetermined period from beginning of cold start is introduced into the in-compressor passage without passing through a low-temperature radiator. The electronic control unit is configured to increase the flow rate of the low-temperature coolant that flows through the low-temperature coolant circulation circuit during the predetermined period as compared to the flow rate after the predetermined period.

Claims

1. An engine system comprising:

an internal combustion engine;

a turbocharger having a compressor arranged in an intake passage to supercharge intake air of the internal combustion engine and a turbine driven by exhaust gas from the internal combustion engine;

wherein at least one of EGR gas and blow-by gas is introduced to the intake passage upstream of the compressor;

coolant circulation loops including;

a high-temperature coolant circulation loop circulating coolants at different temperatures;

wherein the high-temperature coolant circulation loop further includes;

a high-temperature water pump to circulate high-temperature coolant for cooling a water jacket of the internal combustion engine; and

a high-temperature radiator to cool the high-temperature coolant; and

a low-temperature coolant circulation loop;

wherein the low-temperature coolant circulation loop further includes;

a low-temperature water pump to circulate low-temperature coolant lower than the high-temperature coolant circulating in the high-temperature coolant circulation loop; and

a low-temperature radiator to cool the low-temperature coolant;

a water-cooled intercooler to exchange heat between intake air of the internal combustion engine and both the high-temperature coolant and the low-temperature coolant via intake air;

wherein the water-cooled intercooler further includes;

an in-cooler high-temperature water passage being a part of the high-temperature coolant circulation loop;

an in-cooler low-temperature water passage being a part of the low-temperature coolant circulation loop; and

an in-cooler intake passage being a part of the intake passage;

wherein the compressor further includes an in-compressor passage being a part of the low-temperature coolant circulation loop, and being arranged in the low-temperature coolant circulation loop at a location at which the low-temperature coolant exiting from the in-cooler low-temperature water passage is introduced into the in-compressor passage without passing through the low-temperature radiator during a predetermined period being defined as from beginning of a cold start phase to a completion of a warm-up phase of the internal combustion engine; and

an electronic control unit programmed to drive the low-temperature water pump during the predetermined period in order to cause a flow rate of the low-temperature coolant flowing through the low-temperature coolant circulation loop during the predetermined period to be higher than the flow rate after the predetermined period.

2. The engine system according to claim 1,

wherein the low-temperature coolant circulation loop includes a bypass passage that bypasses the in-cooler low-temperature water passage;

wherein the internal combustion engine includes at least one of a turbocharger bearing and exhaust emission control catalyst, useable as a heat source for the low temperature coolant, that includes an in-device passage that is part of the bypass passage;

wherein the in-compressor passage is arranged in the bypass passage at a portion downstream of the in-device passage;

wherein the low-temperature coolant circulation loop includes a branch passage that connects a portion between a downstream end of the bypass passage and the in-cooler low-temperature water passage with a portion between the in-device passage and the in-compressor passage;

wherein a proportion of the flow rate of the low-temperature coolant flowing into the compressor via the branch passage within the low-temperature coolant that has passed through the intercooler is varied via a passage selector valve;

wherein the electronic control unit is further programmed to control the passage selector valve during the predetermined period to cause the proportion of the flow rate of the low-temperature coolant to be higher than the proportion of the flow rate of the low temperature coolant after the predetermined period.

3. The engine system according to claim 2,

wherein the electronic control unit is programmed to control the passage selector valve in order to cause all the low-temperature coolant passing through the intercooler to flow into the compressor via the branch passage;

and

wherein the electronic control unit is programmed to control the passage selector valve after the predetermined period to cause all the low-temperature coolant passing through the intercooler to be supplied to at least one of a reservoir tank and a low temperature thermostat of the low-temperature coolant loop without passing through the branch passage.

4. The engine system according to claim 2, wherein

the in-device passage is a passage to supply the low-temperature coolant through a bearing of the turbocharger.

5. The engine system according to claim 1,

wherein the low-temperature coolant circulation loop includes a bypass passage bypassing the in-cooler low-temperature water passage;

wherein the internal combustion engine further includes;

at least one of a turbocharger bearing and exhaust emission control catalyst for heating the low-temperature coolant; and

an in-device passage being part of the bypass passage; and

wherein the in-compressor passage is located at a portion at which both the low-temperature coolant that flows out from the in-cooler low-temperature water passage and the low-temperature coolant that flows out from the bypass passage flow.

6. The engine system according to claim 1, wherein the predetermined period is a period of a change in the temperature of the high-temperature coolant falling within a predetermined range after beginning of cold start.

7. The engine system according to claim 1, wherein the predetermined period is at least one of:

a period at which a wall temperature of the intake passage downstream of the compressor reaches a dew point of intake air containing at least one of EGR gas and blow-by gas; and

a period at which a lapse of a predetermined margin time that begins from the period at which the wall temperature has reached the dew point.