Diesel engine powered transportation refrigeration system
Solution Overview
Problem
Transportation refrigeration systems face challenges in diesel particulate filter regeneration due to low exhaust temperatures during low-speed and low-load operations, which prevents passive or active regeneration of soot particles.
Innovation Solution
An air control valve is connected to the diesel engine to control airflow, increasing exhaust gas temperature and aiding in the regeneration of the diesel particulate filter, ensuring effective combustion of particulates even at low engine loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the diesel engine operates at low speed and low load, then the refrigeration system can maintain cooling function, but the exhaust temperature drops below catalyst activation temperature preventing DPF regeneration
Solution Approach 1:
The system changes the air-fuel ratio parameter by introducing additional air into the exhaust stream downstream of the combustion chamber. This parameter change raises the exhaust gas temperature above the catalyst activation temperature, enabling DPF regeneration even when the engine operates at low speed and low load conditions
2Reliability
If the air control valve increases airflow to raise exhaust temperature for DPF regeneration, then particulate combustion is enabled, but engine performance may be affected
Solution Approach 1:
The system extracts the air injection function from the engine's primary intake system and places it in the exhaust stream downstream of combustion. This separation allows independent control of exhaust temperature for DPF regeneration without interfering with the engine's combustion process and power output
Solution Approach 2:
An air control valve is introduced as an intermediary device between the atmosphere and the exhaust stream. This intermediary component precisely regulates the amount of air mixed with exhaust gases, enabling reliable DPF regeneration while maintaining engine performance through controlled air-fuel ratio adjustment
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution enables successful regeneration of the diesel particulate filter by maintaining adequate exhaust gas temperatures, ensuring the removal of combustion particulates and preventing their accumulation.
Implementation Method 1
The collected particulates are combusted at the diesel particulate filter via the exhaust gas
Implementation Method 2
a diesel particulate filter in operable communication with the diesel powered engine to filter combustion particulates from an exhaust gas output
Data Source
AI summary
A transport refrigeration system (10) includes a refrigerant vapor compression transport unit (12) including a compressor (14). A drive unit is utilized to provide power to the compressor. The drive unit includes a diesel powered engine (32) and a diesel particulate filter in operable communication with the diesel powered engine to filter combustion particulates from an exhaust gas output from the diesel powered engine. An air control valve is in operable communication with the diesel powered engine to control a flow of air into an air inlet of the diesel powered engine, thereby controlling an exhaust gas temperature of the diesel engine to aid in regeneration of the diesel particulate filter.