Integrated load bank and exhaust heater system with load shed capability for a diesel genset exhaust aftertreatment system

• US 10,260,389 B2
• Filed: 09/25/2017
• Issued: 04/16/2019
• Est. Priority Date: 12/05/2012
• Status: Active Grant

• Current Assignee: Cummins Cal Pacific LLC (Cummins Incorporated)
• Original Assignee: Cummins Cal Pacific LLC (Cummins Incorporated)
• Inventors: Van Niekerk, Herman, Wiemers, Eric G., Yragui, Mark
• Primary Examiner(s): Lee, Brandon D
• Application Number:
  US15/714,148
• Publication Number:
  US 20180010503A1
• Time in Patent Office: 568 Days
• CPC Class Codes: F01N 2590/10 for stationary applications
• CPC Class Codes: F01N 2900/0422 measuring the elapsed time
• CPC Class Codes: F01N 3/027 using electric or magnetic heating means
• CPC Class Codes: F01N 3/2013 using electric or magnetic heating means
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 9/00 Electrical control of exhaust gas treating apparatus monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00
• CPC Class Codes: F01N 9/002 of filter regeneration, e.g. detection of clogging
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An integrated load bank and exhaust heater for a diesel genset exhaust aftertreatment system of the type having a diesel particulate filter (DPF) and a selective catalytic reduction (SCR) section. The load bank/heater can function as a load bank when testing the genset, as a heat source to optimize SCR efficiency, as to thermally regenerate the DPF filter.

Claims

1. A method of distributing power from a genset having an output power capacity to an electrical load powered by the genset and to a load bank/heater in an exhaust after treatment (AT) system coupled to the genset, the method including:

delivering power from the genset to the electrical load;

delivering power from the genset to the load bank/heater to heat exhaust from the genset;

monitoring power demand on the genset while delivering power to the electrical load and the load bank/heater;

determining whether the power demand of the electrical load is increasing at a high rate of change, wherein the high rate of change indicates that the power demand of the electrical load is projected to become greater than at least one of a selected output power capacity and a genset output power capacity; and

reducing the amount of power applied to the load bank/heater in response to the electrical load power demand increasing at the high rate of change to preemptively shed load to prevent the power demand on the genset from becoming greater than at least one of the selected output power capacity and the genset output power capacity.

2. The method of claim 1 wherein reducing the amount of power applied to the load bank/heater includes discontinuing the application of power to the load bank/heater when the amount of power demanded by the electrical load about equals or exceeds the genset output power capacity or the selected output capacity.

3. The method of claim 1 wherein delivering power from the genset to the load bank/heater to heat exhaust from the genset further comprises delivering power from the genset to the load bank/heater to heat exhaust from the genset to maintain exhaust temperature within a selected range.

4. The method of claim 1 wherein:

applying power to the load bank/heater includes applying power to the load bank/heater during operation in a diesel particulate filter (DPF) regeneration mode;

determining whether the electrical load demands power during the DPF filter regeneration mode; and

reducing the amount of power applied to the load bank/heater during the DPF filter regeneration mode in response to the electrical load demanding power during the DPF filter regeneration mode.

5. The method of claim 1 wherein:

applying power to the load bank/heater includes applying power to the load bank/heater during operation in an AT run mode;

determining whether the electrical load demands power during the AT run mode; and

reducing the amount of power applied to the load bank/heater during the AT run mode in response to the electrical load demanding power during the AT run mode.

6. The method of claim 1 wherein the high rate of change for power demand is determined with a differential or second order differential of the increase in power demand.

7. An exhaust after treatment system for use with a genset having an output power capacity coupled to an electrical load, including:

a load bank/heater configured to be powered by the genset and to heat exhaust from the genset;

a power sensor to monitor power demand on the genset; and

an electronic controller coupled to the load bank/heater and the power sensor, the electronic controller configured to;

control the amount of power applied to the load bank/heater;

determine whether the power demand of the electrical load is increasing at a high rate of change, wherein the high rate of change indicates that the power demand is projected to become greater than at least one of a selected output power capacity and a genset output power capacity; and

reduce the amount of power applied to the load bank/heater in response to the electrical load power demand increasing at the high rate of change to preemptively shed load to prevent the power demand on the genset from becoming greater than at least one of the selected output power capacity and the genset output power capacity.

8. The exhaust after treatment system of claim 7 wherein the electronic controller discontinues the application of power to the load bank/heater when the amount of power demanded by the electrical load exceeds the genset output power capacity or the selected limit.

9. The exhaust after treatment system of claim 7 wherein the electronic controller includes:

a switch coupling power from the genset to the load bank/heater; and

a controller coupled to the switch and the power sensor, to control the switch.