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EP-4442975-B1 - COOLANT HEATER PROTECTION SYSTEMS AND METHODS

EP4442975B1EP 4442975 B1EP4442975 B1EP 4442975B1EP-4442975-B1

Inventors

  • Douglas, Jeremy N.
  • TONKIN, STEVEN W.

Dates

Publication Date
20260506
Application Date
20240305

Claims (12)

  1. A coolant heating system for an engine, comprising: a coolant heater (116) including: a housing (208) including: an inlet (212) configured to receive coolant from the engine; and an outlet (216) configured to output coolant to the engine (104); an electrically resistive heating element (204) that is disposed within the housing (208) and that is configured to generate heat when power is applied to the heating element (204); and a temperature sensor (128, 220, 224) configured to measure a temperature of coolant within the housing (208); and a heater control module (124) configured to: receive the temperature from the temperature sensor (128, 220, 224); selectively control application of power to the heating element (204) based on maintaining the temperature at or above a predetermined temperature; selectively detect the presence of a condition based on the temperature; and when the presence of the condition is detected, disconnect the heating element (204) from power, the coolant heating system being characterized in that it further comprises a second temperature sensor (128, 220, 224) configured to measure a second temperature of coolant within the housing (208), wherein the heater control module (124) is configured to receive the second temperature from the second temperature sensor (128, 220, 224), the temperature sensor (128, 220) is configured to measure the temperature of coolant within the inlet; and the second temperature sensor (128, 224) is configured to measure the second temperature of coolant within the outlet, wherein the heater control module is configured to detect the presence of the condition further based on the second temperature.
  2. The coolant heating system of claim 1 wherein the housing (208) is configured to be located vertically below a vertically lowest point of a coolant loop of the engine (104), and no pump is used to pump coolant between the coolant heater (116) and the engine (104).
  3. The coolant heating system of claim 1 wherein the temperature sensor (128, 220, 224) extends through the housing (208) and is configured to directly contact coolant within the housing (208).
  4. The coolant heating system of claim 1 wherein the temperature sensor (128, 220, 224) does not directly contact coolant within the housing (208).
  5. The coolant heating system of claim 1 wherein: the condition is at least a portion of the heating element (204) not being submerged in coolant; and the heater control module (124) is configured to selectively detect the presence of the condition based on the temperature.
  6. The coolant heating system of claim 5 wherein the heater control module (124) is configured to detect the presence of the condition when the temperature is greater than a second predetermined temperature that is greater than the predetermined temperature.
  7. The coolant heating system of claim 5 wherein the heater control module (124) is configured to detect the presence of the condition based on a rate of increase of the temperature.
  8. The coolant heating system of claim 1 wherein: the condition is low coolant flow; and the heater control module (124) is configured to selectively detect the presence of the condition based on the temperature.
  9. The coolant heating system of claim 1 wherein the heater control module (124) is configured to detect the presence of the condition based on a difference between the temperature and the second temperature.
  10. The coolant heating system of claim 1 further comprising a pump (120) configured to pump coolant between the coolant heater (116) and the engine (104), wherein the condition is a fault of the pump (120); and the heater control module (124) is configured to selectively detect the presence of the condition based on the temperature.
  11. The coolant heating system of claim 10, wherein the heater control module (1 2 4 ) is configured to detect the presence of the condition further based on the second temperature.
  12. A method, comprising: receiving a temperature from a temperature sensor (128, 220, 224), the temperature sensor (128, 220, 224) configured to measure a temperature of coolant within a housing (208) of a coolant heater (116), the coolant heater (116) including: the housing including: an inlet (212) configured to receive coolant from an engine (104); and an outlet (216) configured to output coolant to the engine (104); an electrically resistive heating element (204) that is disposed within the housing (208) and that is configured to generate heat when power is applied to the heating element (204); selectively controlling application of power to the heating element ( 2 0 4 ) based on maintaining the temperature at or above a predetermined temperature; selectively detecting the presence of a condition based on the temperature; and when the presence of the condition is detected, disconnecting the heating element (204) from power, the method being characterized by further comprising receiving a temperature from a second temperature sensor (128, 220, 224) configured to measure a second temperature of coolant within the housing (208), wherein the heater control module (124) is configured to receive the second temperature from the second temperature sensor (128, 220, 224), the temperature sensor (128, 220) is configured to measure the temperature of coolant within the inlet (212); and the second temperature sensor (128, 224) is configured to measure the second temperature of coolant within the outlet (216), wherein the step of selectively detecting the presence of a condition is further based on the second temperature.

Description

FIELD The present disclosure relates to coolant heaters, such as for internal combustion engines and other applications, and more particularly to systems and methods for protecting such coolant heaters. BACKGROUND The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. Various different types of internal combustion engines are available. For example, some engines combust gasoline. Other engines combust diesel fuel. Yet other engines combust natural gas or propane. Other engines combust other types of fuel and/or gas. When an engine is on and running, an engine coolant can be used to cool the engine. For example, a coolant pump can be used to pump coolant through the engine and a heat exchanger while the engine is running. The coolant absorbs heat from the engine while the coolant is within the engine. Heat is transferred from the coolant to air and diesel fuel when the coolant is within the heat exchanger. US 4 770 134 A1 discloses an engine preheater comprising a tubular tank adapted to be mounted generally horizontally and having an inlet adjacent one end of the tank for flow of engine coolant into the tank and an outlet adjacent the opposite end of the tank for flow of heated engine coolant out of the tank. The preheater includes an electric heating element in the tank spaced from the inlet of the tank for heating engine coolant in the tank and a temperature sensor inside the tank adjacent the inlet of the tank. The sensor is so positioned relative to the inlet and the heating element that it is adapted accurately to sense the temperature of engine coolant flowing into the tank via the inlet before the incoming engine coolant is substantially heated by the heating element. SUMMARY According to the invention, a coolant heating system in accordance with claim 1 is provided. In further features, the temperature sensor is a thermistor. In further features, the housing is configured to be located vertically below a vertically lowest point of a coolant loop of the engine, and no pump is used to pump coolant between the coolant heater and the engine. In further features, a pump is configured to pump coolant between the coolant heater and the engine. In further features, the temperature sensor extends through the housing and is configured to directly contact coolant within the housing. In further features, the temperature sensor does not directly contact coolant within the housing. According to the invention, a second temperature sensor is configured to measure a second temperature of coolant within the housing, where the heater control module is configured to receive the second temperature from the second temperature sensor. According to the invention, the temperature sensor is configured to measure the temperature of coolant within the inlet; and the second temperature sensor is configured to measure the second temperature of coolant within the outlet. In further features: the condition is at least a portion of the heating element not being submerged in coolant; and the heater control module is configured to selectively detect the presence of the condition based on the temperature. In further features, the heater control module is configured to detect the presence of the condition when the temperature is greater than a second predetermined temperature that is greater than the predetermined temperature. In further features, the heater control module is configured to detect the presence of the condition based on a rate of increase of the temperature. In further features, the heater control module is configured to detect the presence of the condition when the rate of increase of the temperature is greater than a predetermined rate of temperature increase. In further features: the condition is low coolant flow; and the heater control module is configured to selectively detect the presence of the condition based on the temperature. According to the invention, the second temperature sensor configured to measure a second temperature of coolant within the housing, where the heater control module is configured to detect the presence of the condition further based on the second temperature. In further features, the heater control module is configured to detect the presence of the condition based on a difference between the temperature and the second temperature. In further features, the heater control module is configured to detect the presence of the condition when the difference is greater than a predetermined temperature difference. In further features, a pump is configured to pump coolant between the coolant heater and the engine, where the condition is a fault of the pum