Текст 4. Nuclear power stations

The first industrial nuclear power station in the world was constructed in Obninsk not far from Moscow in 1954. The station was put into operation two years earlier than the British one and three and a half years earlier that the American nuclear power-stations.

A number of nuclear power-stations have been put into operation since 1954. The Beloyarskaya nuclear power station named after academician Kurchatov may serve an example of the peaceful use of atomic energy. The scientists and engineers achieved a nuclear superheating of steam directly in the reactor itself before steam is carried into the turbine. It is certainly an important contribution to nuclear engineering achieved for the first time in the world.

We might mention here another important achievement that is the first nuclear installation where thermal energy generated in the reactor is transformed directly into electrical energy. Speaking of the peaceful use of atomic energy it is also necessary to mention our nuclear ice-breakers. “Lenin” is the world’s first ice-breaker with nuclear installation. Its machine installation is of a steam turbine type and steam is produced by three reactors and six steam generators.

Текст 5. A steam engine

A steam engine is a device that converts the potential energy that exists as pressure in steam, and converts that to mechanical force. Early examples were the steam locomotive trains, and steamships that relied on these steam engines for movement. The Industrial Revolution came about primarily because of the steam engine. The thirty seconds or so required to develop pressure made steam less favored for automobiles, which are generally powered by internal combustion engines.

The first steam device was invented by Hero of Alexandria, a Greek, before 300 BC, but never utilized as anything other than a toy. While designs had been created by varous people in the meanwhile, the first practical steam engine was patented by James Watt, a Scottish inventor, in 1769. Steam engines are of various types but most are reciprocal piston or turbine devices.

The strength of the steam engine for modern purposes is in its ability to convert raw heat into mechanical work. Unlike the internal combustion engine, the steam engine is not particular about the source of heat. Since the oxygen for combustion is unmetered, steam engines burn fuel cleanly and efficiently, with relatively little pollution.

One source of inefficiency is that the condenser causes losses by being somewhat hotter than the outside world. Thus any closed-cycle engine will always be somewhat less efficient than any open-cycle engine, because of condenser losses.

Most notably, without the use of a steam engine nuclear energy could not be harnessed for useful work, as a nuclear reactor does not directly generate either mechanical work or electrical energy – the reactor itself does nothing but sit there and get hot. It is the steam engine which converts that heat into useful work.

Текст 6. First inventors

Thomas Newcomen (1663 – 1729) was an ironmonger by profession, but made a significant contribution to the Industrial Revolution with his invention of the atmospheric steam engine.

Thomas Newcomen was born in Dartmouth, Devon in 1663 and established himself as an ironmonger in his home town. Some of his biggest customers were Cornish tin mine owners, who faced considerable difficulties with flooding as mines became progressively deeper. The standard methods to remove the water – manual pumping or teams of horses hauling buckets on a rope – were slow and expensive, and they sought an alternative.

Contemporary engines worked by using condensed steam to make a vacuum, but whereas Thomas Savery's pump of 1698 had just used the vacuum to pull the water up, Newcomen created his vacuum inside a cylinder and used it to pull down a piston. He then used a lever to transfer the force to the pump shaft that went down the mine: it was the first practical engine to use a piston in a cylinder. Casting the cylinders and getting the pistons to fit was pushing the limit of existing technology, so Newcomen deliberately made the piston marginally smaller than the cylinder and sealed the gap with a ring of wet leather or rope. However, to avoid infringing Savery's patent Newcomen was forced to go into partnership with him.

Thomas Newcomen invented his steam engine in 1705 to pump water from English coal mines. This machine was developed by 1720 and remained in use for 50 years.

His first working engine was installed at a coalmine at Dudley Castle in Staffordshire in 1712. It had a cylinder 21 inches in diameter and nearly eight feet long, and it worked at twelve strokes a minute, raising ten gallons of water from a depth of 156 feet; approximately 5.5 horse power. The engines were rugged and reliable and worked day and night, but were extremely inefficient.

Newcomen engines were extremely expensive but were nevertheless very successful. By the time Newcomen died on 5 August 1729 there were at least one hundred of his engines in Britain and across Europe.

In Russia there was another inventor: Ivan Polzunov (1728–1766)

In 1763 a self-taught man (самоучка), the son of a Russian soldier Ivan Polzunov (1728–1766) worked out the project of the first universal steam engine. The construction of the engine involved great difficulties due to lack (из-за недостатка) of necessary instruments, qualified assistants and in general lack of help and support. Polzunov had to do everything with his own hands. Polzunov’s engine had been working from August to November 10, 1766, when it was stopped and put out of operation because of a leak in the boilers. But Polzunov did not live to see the results of his work. He died in poverty on May 27, 1766.

Later, in the course of the industrial revolution in England, a number of inventors designed steam engines because the demand for these machines was urgent. A prominent place among these early inventors belongs to James Watt, an instrument maker at the University of Glasgow who perfected Newcomen’s engine.

Текст 7. James Watt (1736–1819)

James Watt was born in Greenock on 18 January 1736. His father was a prosperous shipwright. Watt initially worked as a maker of mathematical instruments but soon began to become interested in steam engines. The first working steam engine had been patented in 1698 and by the time of Watt's birth, Newcomen engines were pumping water from mines all over the country.

James Watt worked as an instrument maker at the University of Glasgow. In around 1764 he was given a model Newcomen engine to repair. While repairing the model, Watt noticed the large waste of energy due to alternately heating the steam cylinder with steam and cooling it with injection water. He realized that this loss could be reduced by keeping the cylinder as hot as possible with insulation. He understood that it was possible to use a separate condenser or water-cooled chamber which could be connected to the steam cylinder at the necessary time by a valve.

Later he closed the top of the steam cylinder with a cover or cylinder head, introduced steam alternately on both sides of the piston and thus made the engine double acting. He invented a governer to regulate the speed of the engine, a slide valve to control the admission, expansion and exhaust of the steam, a pump to remove the air and condensate from the condenser, and, in fact, brought the steam engine to a fairly high state of development. His first patent in 1769 covered this device and other improvements on Newcomen's engine.

Watt's partner and backer was the inventor John Roebuck. In 1775, Roebuck's interest was taken over by Matthew Boulton who owned an engineering works in Birmingham. Together he and Watt began to manufacture steam engines. Boulton & Watt became the most important engineering firm in the country, meeting considerable demand. Initially this came from Cornish mine owners, but extended to paper, flour, cotton and iron mills, as well as distilleries, canals and waterworks. In 1785, Watt and Boulton were elected fellows of the Royal Society.

By 1790 Watt was a wealthy man and in 1800 he retired and devoted himself entirely to research work. He patented several other important inventions including the rotary engine, the double-action engine and the steam indicator, which records the steam pressure inside the engine.

Watt died on 19 August 1819. A unit of measurement of electrical and mechanical power – the watt – is named in his honour.