Booster Bearing Failure Reduction Through a Novel Thermodynamic Analysis

The gas booster station of a steel works has experienced excessive bearing failures since commissioning over two decades ago. This station was designed with redundancy, allowing for automatic switch-over between two gas booster fans. Bearing failures were observed, on average once every 15.7 days, with instances where both fans experienced simultaneous downtime. Booster failures resulted in regular station downtime, preventing Coke Oven Gas (COG) transport to an end user. This flammable by-product is used as a heat source and all unutilized volumes are flared, resulting in energy wastages. Furthermore, the absence of COG increases Natural Gas (NG) usage, procured at a cost. Traditional root cause analysis techniques failed to identify the cause of these excessive bearing failures. However, multiple in-depth data analysis studies resulted in a thermodynamic investigation, exposing liquid and solid particles within the COG to be responsible for the failures. This allowed for the design of an in-line particle collector, eliminating excessive failures. Following the particle collector installation, only two strategic bearing changes took place over the next 41 weeks, with reduced bearing vibration levels compared to before. The station experienced no failure downtime during this period, resulting in reduced COG flaring and thus improved energy utilization.

EVALUATION OF SMART BOOSTER FANS AND DAMPERS FOR ADVANCED HVAC SYSTEMS

ABSTRACT There is potential to significantly reduce CO2 emissions by increasing the efficiency and reducing the duty cycle of HVAC systems by using smart booster fans and dampers. Smart booster fans fit in the vents within a home, operating quietly on low power (2W) to augment HVAC systems and improve their performance. In this study, a prototype duct system is used to measure and evaluate the ability for smart booster fans and dampers to control airflow to different vents for the purpose of increasing the efficiency of HVAC systems. Four case studies were evaluated: an HVAC system (1) without any fans or dampers, (2) with a fan installed in one vent, but without any dampers, (3) with dampers installed at the vents, but without any fans, and (4) with both fan and dampers installed. The results from both the experimental and numerical evaluation show that the smart booster fan and dampers can significantly improve the airflow at a vent that is underperforming. For example, the airflow at the last vent in a ducting branch was increased from 17 to 37 CFM when a smart booster fan was installed at this vent. Results from the numerical analysis show that for the case of an underperforming vent during the winter season the HVAC running time may be reduced from 24 hr/day to 5.6 hr/day. Furthermore, results from the numerical analysis show the HVAC running time is further reduced to 4.5 hr/day for cases 3 and 4.

Criteria for the Choice of Fans for use in Thermal Power Plant Applications

Large fans for the thermal power industry operate more and more on part load. This paper discusses how the total cost of an investment is increasingly based on the inclusion of the operating costs. Today there is still a high demand for conventional thermal power stations. New ones are under construction and existing ones are in the process of conversion with new desulfurization units; more and more emphasis is being concentrated on: Operating efficiency Technical reliability The environment and noise and, of course, Return on investment Because these priorities are contradictory, the objective of this paper is to guide the reader to the best choice of fan technology given differing circumstances. The correct choice is important concerning primary air, forced draft, induced draft and booster fans which can represent a total power consumption of 2–4 per cent in a 350–600 MW power plant depending on the quality of coal used and the boiler type. These fans are generally characterized by a large volume flow and a relatively large pressure and can be of the centrifugal or axial type. Many solutions are possible for controlling the air flow of these fans. The main ones will be examined by looking at their general principles, their performance and characteristics, and then comparing them from an energy consumption point of view.