Engine warm-up apparatus for vehicle

• US 10,494,985 B2
• Filed: 07/17/2017
• Issued: 12/03/2019
• Est. Priority Date: 07/20/2016
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Okamura, Toru, Nara, Kenichi, Tanioka, Kuniyoshi
• Primary Examiner(s): Nguyen, Hung Q
• Assistant Examiner(s): Greene, Mark L.
• Application Number:
  US15/651,268
• Publication Number:
  US 20180023453A1
• Time in Patent Office: 869 Days
• CPC Class Codes: F01P 11/20 concerning atmospheric freezing conditions, e.g. automatically draining or heating during frosty weather
• CPC Class Codes: F01P 2011/205 using heat-accumulators
• CPC Class Codes: F01P 2025/50 using two or more temperature sensors
• CPC Class Codes: F01P 2025/52 Heat exchanger temperature
• CPC Class Codes: F01P 2060/18 Heater
• CPC Class Codes: F01P 7/165 characterised by systems with two or more loops
• 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: G01K 13/02 for measuring temperature of moving fluids or granular materials capable of flow
• CPC Class Codes: G01K 13/026 of moving liquids
• CPC Class Codes: G01M 15/048 by monitoring temperature

Abstract

A warm-up device is provided in a cooling-water circuit, through which cooling water is circulated so as to pass through an engine. The warm-up device has a heat accumulating passage, in which a heat accumulating device is provided, and an accumulating-device bypassing passage bypassing the heat accumulating device. A waste-heat collecting device is provided in the cooling-water circuit so that heat is collected from exhaust gas from the engine and such collected heat is accumulated in the heat accumulating device. The cooling water is circulated through the heat accumulating device during a start-up operation of the engine in order to heat the cooling water flowing into the engine so as to quickly warm up the engine.

Claims

1. An engine warm-up apparatus for a vehicle comprising:

a cooling-water circuit for circulating cooling water through an engine of the vehicle;

a warm-up device arranged in the cooling-water circuit in such a way that the warm-up device works as a fluid resistance for a flow of the cooling water flowing into the engine, wherein the warm-up device operatively heats the cooling water during a start-up operation of the engine,

wherein the warm-up device comprises;

(i) a heat accumulating device having heat accumulating material for carrying out heat exchange between the cooling water and the heat accumulating material in order that waste heat of the engine is accumulated in the heat accumulating material and/or heat accumulated in the heat accumulating material is radiated to the cooling water;

(ii) a passage switching device for switching a water passage for the cooling water flowing into the engine from a heat accumulating passage in which the cooling water flows through the heat accumulating device to an accumulating-device bypassing passage in which the cooling water bypasses the heat accumulating device, or vice versa; and

(iii) an electronic control unit for controlling the passage switching device in such a way that;

(iii-a) the cooling water is circulated through the heat accumulating device when a temperature of the cooling water flowing into the warm-up device is lower than a first threshold value during the start-up operation of the engine, wherein the first threshold value corresponds to a temperature indicating a first-stage completion of a warm-up operation of the engine;

(iii-b) the cooling water is circulated through the accumulating-device bypassing passage when the engine is in its operation and when the temperature of the cooling water flowing into the warm-up device is higher than the first threshold value but lower than a second threshold value, wherein the second threshold value corresponds to a temperature indicating a second-stage completion of the warm-up operation of the engine and the second threshold value is higher than the first threshold value; and

(iii-c) the cooling water is circulated through the heat accumulating device when the temperature of the cooling water flowing into the warm-up device is higher than the second threshold value and when the operation of the engine is temporarily stopped.

2. The engine warm-up apparatus according to claim 1, wherein

the electronic control unit further controls the passage switching device in such a way that the cooling water flowing into the warm-up device is circulated through the accumulating-device bypassing passage, when the temperature of the cooling water flowing into the warm-up device is higher than the second threshold value during the engine is in its operation.

3. The engine warm-up apparatus according to claim 1, further comprising:

a radiator provided in the cooling-water circuit for cooling down the cooling water; and

a thermostat for circulating the cooling water through the radiator when the temperature of the cooling water flowing into the warm-up device is higher than a third threshold value,

wherein the third threshold value is higher than the second threshold value.

4. The engine warm-up apparatus according to claim 1, wherein

a flow amount of the cooling water flowing into the engine via the accumulating-device bypassing passage is larger than a flow amount of the cooling water flowing into the engine via the heat accumulating device.

5. The engine warm-up apparatus according to claim 1, wherein

the cooling water circuit is composed of a first cooling-water circuit and a second cooling-water circuit,

the cooling water passes through the engine when the cooling water is circulated in the first cooling-water circuit,

the cooling water bypasses the engine when the cooling water is circulated in the second cooling-water circuit, and

the warm-up device is provided in the first cooling-water circuit.

6. The engine warm-up apparatus according to claim 5, wherein

at least one of the following components is provided in the second cooling-water circuit,

(i) a throttle body for the engine,

(ii) an exhaust gas cooler for cooling down a part of exhaust gas to be re-circulated from an exhaust system to an intake system of the engine,

(iii) a heat exchanger for heating the cooling water by use of heat of the exhaust gas from the engine, and

(iv) a heater core for heating air to be supplied into a passenger compartment of the vehicle,

wherein a predetermined amount of the cooling water is circulated in the second cooling-water circuit when the cooling water is circulated through the heat accumulating device of the warm-up device.

7. The engine warm-up apparatus according to claim 1, wherein

the heat accumulating device has a heat insulating casing for accommodating therein the heat accumulating material and suppressing heat transfer between an inside and an outside of the heat insulating casing, and

the heat accumulating material is composed of:

(i) material which accumulates heat by a phase change from a solid state to a liquid phase;

or

(ii) material which accumulates heat by electronic phase transition.

8. The engine warm-up apparatus according to claim 1, wherein

the heat accumulating material is composed of chemical heat accumulating material, which carries out heat accumulation and heat radiation in a reversible fashion by chemical reaction with water or ammonia, and

the heat accumulating device is composed of:

(i) a chemical heat accumulating casing;

(ii) a pipe connected to an inside of the chemical heat accumulating casing; and

(iii) a heat exchanger connected to the inside of the chemical heat accumulating casing via the pipe,

wherein the heat exchanger evaporates or condenses the water or ammonia, which is separated from the chemical heat accumulating material in the inside of the chemical heat accumulating casing.

9. The engine warm-up apparatus according to claim 1, wherein

the heat accumulating material is composed of such material, which carries out a phase change from a solid state to a liquid phase, and

the warm-up device controls a flow amount of the cooling water flowing into the engine depending on a volume change caused by the phase change of the heat accumulating material.

10. The engine warm-up apparatus according to claim 1, further comprising:

a water pump for circulating the cooling water through the cooling-water circuit, even when the operation of the engine is temporarily stopped.

11. The engine warm-up apparatus according to claim 1, wherein

the cooling water flowing into the warm-up device is circulated through the heat accumulating device and the accumulating-device bypassing passage when the temperature of the cooling water flowing into the warm-up device is higher than a predetermined temperature.

12. An engine warm-up apparatus for a vehicle comprising:

a cooling-water circuit for circulating cooling water through an engine of the vehicle;

a warm-up device arranged in the cooling-water circuit in such a way that the warm-up device works as a fluid resistance for a flow of the cooling water flowing into the engine, wherein the warm-up device operatively heats the cooling water during a start-up operation of the engine,

wherein the warm-up device comprises;

(i) a heat accumulating device having heat accumulating material for carrying out heat exchange between the cooling water and the heat accumulating material in order that waste heat of the engine is accumulated in the heat accumulating material and/or heat accumulated in the heat accumulating material is radiated to the cooling water;

(ii) a passage switching device for switching a water passage for the cooling water flowing into the engine from a heat accumulating passage in which the cooling water flows through the heat accumulating device to an accumulating-device bypassing passage in which the cooling water bypasses the heat accumulating device; and

(iii) an electronic control unit for controlling the passage switching device in such a way that;

(iii-a) the cooling water is circulated only through the heat accumulating device when a temperature of the cooling water flowing into the warm-up device is lower than a first threshold value during the start-up operation of the engine so as to carry out a warm-up mode, wherein the first threshold value corresponds to a temperature indicating a first-stage completion of a warm-up operation of the engine;

(iii-b) the cooling water is circulated only through the accumulating-device bypassing passage when the engine is in its operation and when the temperature of the cooling water flowing into the warm-up device is higher than the first threshold value so as to carry out a cooling mode; and

(iii-c) the cooling water is circulated only through the heat accumulating device when the temperature of the cooling water flowing into the warm-up device is higher than a second threshold value during the operation of the engine is temporarily stopped so as to carry out a heat accumulating mode, wherein the second threshold value corresponds to a temperature indicating a second-stage completion of the warm-up operation of the engine and the second threshold value is higher than the first threshold value.

13. The engine warm-up apparatus according to claim 12, further comprising:

a radiator provided in the cooling-water circuit for cooling down the cooling water; and

a thermostat for circulating the cooling water through the radiator when the temperature of the cooling water flowing into the warm-up device is higher than a third threshold value,

wherein the third threshold value is higher than the second threshold value.