Energy Conservation

by MR. H. BROWN, member.
At the Durrington Community Centre – 11th January, 1989.

In a wide ranging survey of fuel use in industry Mr. Brown traced the effects of economic, environmental and strategic situations on the technology and operation of boilers. The survey started from World War II, with the late Lord Shinwell as the first Minister of Fuel and Power, when the need for reducing wasteful use of fuel was vital.

To-day, additional constraints of the limited availability of fossil fuels, and the more recent scare of ecological damage worldwide attributed to burning fossil fuels, put the spotlight on the technology of energy supply.

In 1948 the M.O.P. Fuel Efficiency Branch was enlarged to some 200 engineers in 12 regions and made available for consultation by industrial concerns. Experience showed that visual inspection of plant was inadequate and so mobile test units were set up, equipped with a standard range of instruments that could be easily installed temporarily on commercial boilers. This service continued in an expanded form from 1954 under N.I.F.E.S. (National Industrial Fuel Efficiency Service).

From published reports of N.I.F.E.S. the savings indicated from over 2000 surveys between 1954 and 1960 was 20.5% . Some 75% of recommendations had been accepted. This did not include power stations, which were outside the scope of N.I.F.E.S. Some examples were given.

After the war the relative cheapness of oil led to many coal fired boilers being re-equipped to burn oil. Subsequently the Iranian Nationalisation of the oil wells and consequent large increase of cost led to conversions of boilers to burn gas. Of course, mismatches were often met with boilers originaly designed to burn coal with consequent poor operation and costly maintenance.

Many installations were found to be operating with all of a number of boilers on load continuously, whatever the load, the average load factor per boiler was about 30%. Advice was given to cut down the boilers on load – an obvious enough thing to do, – but its necessity indicated the serious lack of management interest. Many firms failed to understand the economics of operation or the techniques of combustion.

Visual air pollution – smoke and “smog” – often resulted from poor operation. The insidious chemical pollution, e.g. acid rain so topical to-day was barely noticed – although it is interesting to note that Battersea Power Station operated during much of its life with facilities for the removal of sulphur dioxide.

Interest in “smoke emission” widened after the Manchester Corporation Act of 1945, followed by the first “smokeless zone” in Coventry in 1951. This led to more attention being given to boiler operation and management; the success of these schemes was often measured by the Ringleman Smoke Chart. The London Smog of 1952 caused some 4,000 deaths, followed by 1,000 in 1956 and 750 in 1962. In fact, in the history of the city, for the past 700 years there are recorded references to the evils of burning coal at about 10 yearly intervals.

In the U.K. anyone could fire a boiler legally (and still can) and it became obvious as a major step to meet the smoke problem that operational training was necessary. A Boiler Operators Course was set up in 1955 to give on-site training for six months in all aspects of operation. Many thousands of the 70,000 or so boiler operators completed the course, but the certificates received had no legal standing – and it still does not.

Enthusiasm for these improvements waned after the initial objectives had been achieved, but work on the Clean Air Bill proceeded until the Act was passed in 1956. The closure of the Suez canal that year led to substantial further increases in oil prices to meet the cost of the Cape route. Interest in fuel efficiency was consequently re-kindled. The Clean Air Act came into force 1st June 1958, and this compelled many further improvements in operation as well as the preparation of coal for use, such as washing and grading. The sale of gimmicks of dubious value abounded which proved easier to sell than the less tangible but more effective good advice. Generally simple adjustments to the air/fuel ratio, with the intelligent use of straight forward instruments were all that was needed to comply with the Act. This is also the basic requirement for efficient combustion – thus energy efficiency improved in the pursuit of Clean Air.

The Act required only the removal of solids in the emmissions, not the removal of deleterious invisible products; the problem had not then reached the public opprobrium it has to-day! These problems are more difficult to achieve and very costly – compared with the economy achieved in dealing with solids.

Many improvements in boiler concepts and design resulted from these pressures. Modular boilers, and modular burners allowed for better efficiency at low loads. Better instrumentation was provided, although unfortunately it was not always used intelligently. Education and training was still desperately needed and an annual conference and exhibition for managers and senior staff was instituted. There seemed to be difficulty in persuading management of the financial benefits of proper operation of their energy consumption!

Competition between coal, oil and gas followed the North Sea Oil/Gas developments. Also the increasing availability of oil, gas and
nuclear-based electricity contributed to cleaner air with these more refined fuels. Nevertheless planners of projects often were limited by cash and short cuts were made in the choice of plant and/or services – often thereby increasing recurring maintenance costs. Furthermore lack of proper commissioning tests led to failures and poor operation.

The 1973 coal strike resulted in the imposition of the 3 day working week at factories. In this auto-controls were re-set and lighting levels reduced to reduce fuel consumption. It is of more than passing interest that production levels in 3 days almost equalled that of the 5 day week! In this period the experience of the previous 30 years was immediately to hand. To gain from this the government offered to pay a fee of £25. per day for visits by fuel consultants to premises to advise on efficiency measures. As a result, hundreds of engineers became available.

Mr. Brown also touched on aspects of domestic heating as well as C.H.P. (combined heat and power generation), wind and wave power and heat recovery systems. The current impack of “acid rain” on fuel use was beyond the scope of this review.

Finally, it is clear from much of this experience that efficiency pays financially, saves ecologically but can only be achieved by vigilance and good management.