# US 10,245,921 B2 · System and method for controlling coolant flow through a heater core of a vehicle based upon an estimated heater core air out temperature > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,245,921 B2 - Document ID: US10245921B2 - Status: Granted - Kind: B2 - Application number: 15/619,718 - Filed: 2017-06-12 - Published: 2018-12-13 - Granted: 2019-04-02 - Earliest claimed: 2017-06-12 - Assignees: GM Global Technology Operations LLC - Applicants: GM Global Technology Operations LLC - Inventors: Prashant V. Mer; Vish S. Iyer; Goutham Ethiraj Shivashankar - Web page: https://patentgrep.com/patent/US10245921B2 ## CPC - B60H 1/00807: {the input being a specific way of measuring or calculating an air or coolant temperature} - B60H 1/00885: {Controlling the flow of heating or cooling liquid, e.g. valves or pumps (B60H1/00899 takes precedence; constructions of valves B60H1/00485)} - B60H 1/04: from cooling liquid of the plant {(B60H1/025, B60H1/03 take precedence)} - B60H: ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES ## Abstract A system according to the principles of the present disclosure includes a temperature estimation module and a coolant flow control module. The temperature estimation module can determine an estimate of a heater core air out temperature of a vehicle based upon a heater core inlet coolant temperature, a heater core outlet coolant temperature, an estimated volumetric air flowrate, and an estimated volumetric coolant flowrate. The coolant flow control module can control a rate at which coolant flows to a heater core of the vehicle by adjusting a position of a coolant control valve of the vehicle or an output of a coolant pump of the vehicle. The coolant flow control module can control the coolant flowrate to decrease a difference between a target heater core air out temperature and the estimated heater core air out temperature. ## Claims ### Claim 1 A system comprising: a temperature estimation module configured to determine an estimate of a heater core air out temperature of a vehicle based upon a heater core inlet coolant temperature, a heater core outlet coolant temperature, an estimated volumetric air flowrate, and an estimated volumetric coolant flowrate, wherein the temperature estimation module is configured to estimate the heater core air out temperature using a least square estimation and is configured to estimate the heater core air out temperature based upon the heater core inlet coolant temperature, the heater core outlet coolant temperature, a volumetric coolant flowrate, and a volumetric air flowrate, wherein the temperature estimation module is configured to estimate the heater core air out temperature according to α1{dot over (ν)}clnt+α2{dot over (ν)}air+α3TClnt,In+α4TClnt,Out+α5, where {dot over (ν)}clnt is a volumetric coolant flowrate, {dot over (ν)}air is the volumetric air flowrate TClnt,In is the heater core inlet coolant temperature, TClnt,Out is the heater core outlet coolant temperature, and αi represents respective least square estimate coefficients; and a coolant flow control module configured to: control a coolant flowrate at which coolant flows to a heater core of the vehicle by adjusting at least one of a position of a coolant control valve of the vehicle and an output of a coolant pump of the vehicle; and control the coolant flowrate to decrease a difference between a target heater core air out temperature and the estimated heater core air out temperature. ### Claim 2 (depends on 1) The system of claim 1 wherein the estimated heater core air out temperature is bounded by the heater core inlet coolant temperature having a predefined offset and the heater core outlet coolant temperature having a predefined offset. ### Claim 3 (depends on 1) The system of claim 1 wherein the coolant flow control module is configured to compare the difference between the target heater core air out temperature and the estimated heater core air out temperature, determine whether the difference exceeds a predefined error threshold, and controls the coolant flowrate to decrease a difference between the target heater core air out temperature and the estimated heater core air out temperature. ### Claim 4 (depends on 1) The system of claim 1 wherein the target heater core air out temperature is determined based on blower speed and ambient temperature. ### Claim 5 (depends on 1) The system of claim 1 wherein the coolant flow control module is configured to adjust the coolant flowrate based upon at least one of a predetermined coolant flowrate and a predetermined increment. ### Claim 6 (depends on 1) The system of claim 1 wherein the coolant flow control module is configured to adjust the coolant flowrate based upon at least one of a variable coolant flowrate and a variable increment. ### Claim 7 (depends on 6) The system of claim 6 wherein the variable increment is based upon a control setting. ### Claim 8 (depends on 7) The system of claim 7 wherein the control setting comprises at least one of a Proportional-Integral-Derivative (PID) control and a table look-up control. ### Claim 9 (depends on 1) The system of claim 1, further comprising: a heater core inlet coolant temperature sensor disposed at an heater core inlet line to measure the heater core inlet coolant temperature entering a heater core of a vehicle; and a heater core outlet coolant temperature sensor disposed at a heater core outlet line to measure the heater core outlet coolant temperature exiting the heater core. ### Claim 10 (depends on 1) The system of claim 1, further comprising a volumetric coolant flowrate estimation module that is configured to estimate a volumetric coolant flowrate of a coolant. ### Claim 11 (depends on 1) The system of claim 1, further comprising an airflow estimation module that is configured to estimate a volumetric air flowrate. ### Claim 12 (depends on 1) The system of claim 1, further comprising a heater flap control module that is configured to control a heater flap opening to control an amount of air that passes through a heater flap. ### Claim 13 A system comprising: a temperature estimation module configured to determine an estimate of a heater core air out temperature of a vehicle based upon a heater core inlet coolant temperature, a heater core outlet coolant temperature, an estimated volumetric air flowrate, and an estimated volumetric coolant flowrate, wherein the temperature estimation module is configured to estimate the heater core air out temperature using a least square estimation and is configured to estimate the heater core air out temperature based upon the heater core inlet coolant temperature, the heater core outlet coolant temperature, a volumetric coolant flowrate, and a volumetric air flowrate wherein the temperature estimation module is configured to estimate the heater core air out temperature according to α1{dot over (ν)}clnt+α2{dot over (ν)}air+α3TClnt,In+α4TClnt,Out+α5, where {dot over (ν)}clnt is a volumetric coolant flowrate, {dot over (ν)}air is the volumetric air flowrate, TClnt,In is the heater core inlet coolant temperature, TClnt,Out is the heater core outlet coolant temperature, and αi represents respective least square estimate coefficients; and a coolant flow control module configured to: control a rate at which coolant flows to a heater core of the vehicle by adjusting at least one of a position of a coolant control valve of the vehicle and an output of a coolant pump of the vehicle, and control the coolant flowrate to decrease a difference between a target heater core air out temperature and the estimated heater core air out temperature, wherein the target heater core air out temperature is determined based on blower speed and ambient temperature. ### Claim 14 (depends on 13) The system of claim 13 wherein the estimated heater core air out temperature is bounded by the heater core inlet coolant temperature having a predefined offset and the heater core outlet coolant temperature having a predefined offset. ### Claim 15 (depends on 13) The system of claim 13, further comprising: a heater core inlet coolant temperature sensor disposed at an heater core inlet line to measure the heater core inlet coolant temperature entering a heater core of a vehicle; and a heater core outlet coolant temperature sensor disposed at a heater core outlet line to measure the heater core outlet coolant temperature exiting the heater core. ### Claim 16 (depends on 13) The system of claim 13 wherein the coolant flow control module is configured to compare the difference between the target heater core air out temperature and the estimated heater core air out temperature, determine whether the difference exceeds a predefined error threshold, and controls the coolant flowrate to decrease a difference between the target heater core air out temperature and the estimated heater core air out temperature. ### Claim 17 (depends on 13) The system of claim 13 wherein the target heater core air out temperature is determined based on blower speed and ambient temperature. ### Claim 18 (depends on 13) The system of claim 13 wherein the coolant flow control module is configured to adjust the coolant flowrate based upon at least one of a predetermined coolant flowrate and a predetermined increment. ### Claim 19 (depends on 13) The system of claim 13 wherein the coolant flow control module is configured to adjust the coolant flowrate based upon at least one of a variable coolant flowrate and a variable increment. ### Claim 20 (depends on 19) The system of claim 19 wherein the variable increment is based upon a control setting.