This Timeline of heat engine technology describes how heat engines have been known since antiquity but have been made into increasingly useful devices since the 17th century as a better understanding of the processes involved was gained. They continue to be developed today.
A heat pump is a heat engine run in reverse. Work is used to create a heat differential. The timeline includes devices classed as both engines and pumps, as well as identifying significant leaps in human understanding.
1759 - John Harrison uses a bimetallic strip in his third marine chronometer (H3) to compensate for temperature-induced changes in the balance spring. This converts thermal expansion and contraction in two dissimilar solids to mechanical work.
1769 - James Watt patents his first improved atmospheric steam engine, see Watt steam engine with a separate condenser outside the cylinder, doubling the efficiency of earlier engines.
1834 - Jacob Perkins, obtained the first patent for a vapor-compression refrigeration system.
1850s - Rudolf Clausius sets out the concept of the thermodynamic system and positioned entropy as being that in any irreversible process a small amount of heat energy ?Q is incrementally dissipated across the system boundary
1861 - Alphonse Beau de Rochas of France originates the concept of the four-stroke internal-combustion engine by emphasizing the previously unappreciated importance of compressing the fuel-air mixture before ignition.
1861 - Nicolaus Otto patents a two-stroke internal combustion engine building on Lenoir's.
1872 - Pulsometer steam pump, a pistonless pump, patented by Charles Henry Hall. It was inspired by the Savery steam pump.
1873 - The British chemist Sir William Crookes invents the light mill a device which turns the radiant heat of light directly into rotary motion.
1877 - Theorist Ludwig Boltzmann visualized a probabilistic way to measure the entropy of an ensemble of ideal gas particles, in which he defined entropy to be proportional to the logarithm of the number of microstates such a gas could occupy.
1942 - R.S. Gaugler of General Motors patents the idea of the Heat pipe, a heat transfer mechanism that combines the principles of both thermal conductivity and phase transition to efficiently manage the transfer of heat between two solid interfaces.
1950s - The Philips company develop the Stirling-cycle Stirling Cryocooler which converts mechanical energy to a temperature difference.
1959 - Geusic, Schultz-DuBois and Scoville of Bell Telephone Laboratories USA build a Three Level Maser which runs as a quantum heat engine extracting work from the temperature difference of two heat pools.
1962 - William J. Buehler and Frederick Wang discover the Nickel titanium alloy known as Nitinol which has a shape memory dependent on its temperature.
2011 - Michigan State University builds the first wave disk engine. An internal combustion engine which does away with pistons, crankshafts and valves, and replaces them with a disc-shaped shock wave generator.
^Lardner, Dionysius (1840). The Steam Engine Explained and Illustrated. Taylor and Walton. p. 22. Full title: Le Machine volume nuovo, et di molto artificio da fare effetti maravigliosi tanto Spiritali quanto di Animale Operatione, arichito di bellissime figure. Del Sig. Giovanni Branco, Cittadino Romano. In Roma, 1629
^R. Boyle, A Defence of the Doctrine Touching the Spring and Weight of the Air, ... (London: Thomas Robinson, 1662). Available on-line at: Spain's La Biblioteca Virtual de Patrimonio Bibliográfico. Boyle presents his law in "Chap. V. Two new experiments touching the measure of the force of the spring of air compress'd and dilated.", pp. 57-68. On p. 59, Boyle concludes that " ... the same air being brought to a degree of density about twice as that it had before, obtains a spring twice as strong as formerly." That is, doubling the density of a quantity of air doubles its pressure. Since air's density is proportional to its pressure, then for a fixed quantity of air, the product of its pressure and its volume is constant. On page 60, he presents his data on the compression of air: "A Table of the Condensation of the Air." The legend (p. 60) accompanying the table states: "E. What the pressure should be according to the Hypothesis, that supposes the pressures and expansions to be in reciprocal relation." On p. 64, Boyle presents his data on the expansion of air: "A Table of the Rarefaction of the Air."https://bvpb.mcu.es/en/consulta/registro.cmd?id=406806
^Shoichi Toyabe; Takahiro Sagawa; Masahito Ueda; Eiro Muneyuki; Masaki Sano (2010-09-29). "Information heat engine: converting information to energy by feedback control". Nature Physics. 6 (12): 988-992. arXiv:1009.5287. Bibcode:2011NatPh...6..988T. doi:10.1038/nphys1821. We demonstrated that free energy is obtained by a feedback control using the information about the system; information is converted to free energy, as the first realization of Szilard-type Maxwell's demon.