DENTON SMITH – HEAD OF ENGINEERING, GROOTE SCHUUR HOSPITAL ENERGY MANAGEMENT
Improving efficiency to reduce energy costs
Since the changes to the infrastructure of the boiler house and steam lines were introduced between 2009 and 2015, coal consumption has been reduced by 48 per cent at Groote Schuur Hospital in Western Cape, South Africa.
The boiler house and steam reticulation were considered to be in need of a complete overhaul as well as modernisation primarily because the boilers were extremely inefficient. In order to keep up with demand from the hospital for steam, the boiler house was running two eight tonne boilers using six tonnes of coal per hour in the winter and 4.5 tonnes per hour in the summer. This was considered excessive by the head of the hospital engineering department as historically it had been possible to provide all the steam necessary with only one boiler ‘on range’ at a time. The Groote Schuur Hospital boiler
house was built with four individual four tonne coal fired boilers in 1965 to replace the original steam generation system installed in the old hospital basement in the late 1930s. In the mid 1990s, three of the four boilers were replaced with two eight tonne coal fired boilers and one of the four tonne boilers remained. With the three boilers installed, the
idea was that one was to be ‘on range’, one would be on standby and one would be ‘off range’ for maintenance. This system worked well until about 2003 when the effects of just enough maintenance to pass the statuary three- yearly inspections started to become noticeable as the system became less and less efficient. The results of this extremely focused
and limited maintenance meant that the boilers became fowled with soot and fly ash; the induce draft fans and soot
Groote Schuur Hospital
Groote Schuur Hospital is an academic hospital in Observatory, Cape Town, South Africa. It is the training hospital for the University of Cape Town and incorporates 1000 in-patient beds, 32 day clinics and a private hospital with 100 beds. The hospital covers 19 hectares of ground and is 15 stories high, including the engineering service floors situated between each patient floor. Facilities include outpatients, oncology, psychiatric outpatients, academic, private, maternity, laboratories, residences, administration and soon a full forensic pathology mortuary with laboratories. The hospital employs 3900 staff, of whom 73 provide engineering services
ranging from clinical engineering (healthcare technology; 12 engineering disciplines) to general engineering services (25 engineering disciplines). It is one of two academic hospitals in Cape Town and is involved in outreach
projects that extend to local and international health institutions where, not only are medical and nursing outreach projects linked to development of healthcare locally, nationally and internationally, but the engineering department is helping to open up communication channels between clinicians, hospitals and private enterprises such as the Global Green and Healthy Hospitals (GGHH) initiative.
separators in the smoke room of the boiler house were so full of holes that they had little to no effect on the extraction of the soot and fly ash from the boilers and associated flues. The limited maintenance extended to the steam reticulation, which as a result had a defective steam trapping system as well as many leaks. As this limited maintenance continued, the load on the boilers increased due to the excessive leaks in the steam reticulation as well as the faulty condensate return system. As the condensate being returned did not equal the steam output, more and more make up water was being added to the system. This resulted in the
Denton Smith
Denton Smith is the head of engineering at Groote Schuur Hospital and serves as a member of the executive management of the hospital. He was appointed in 2011. Denton has a National Engineering Diploma in Electro Mechanical Engineering as well as a Post Grad Diploma in Advanced Project Management and has a passion for hospital engineering and a drive to make hospitals efficient. He wishes to thank Dr B Patel, CEO of Groote Schuur Hospital, for her continued support.
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increased consumption of boiler water treatment chemicals and lowered the temperature of the water that was being fed into the boilers, in turn requiring more coal to be burned in order to make up for this lower feed water temperature. The continued high coal consumption
led to less stored coal and frequent breakdowns of the conveyors that deliver the coal from the coal storage bunker to the boiler coal feed hoppers. As the coal conveyor system was designed to run a stop-start rather than a continuous operation, breakdowns were frequent. During conveyor breakdown, a bucket brigade was needed in order to continue with steam production. After hours, on occasions, this bucket brigade could not be formed in time and steam production stopped for up to a few hours. As a result the hospital cooled down as the steam is used for the production of domestic hot water, space heating, cooking and sterilising. This meant that once steam pressure was restored the load on the boilers was even greater. Heavier steam loading on the boilers led to more coal being consumed,
IFHE DIGEST 2018
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