US 2502878 A
Description (OCR text may contain errors)
Apififi HQ c. K. NEWQMBE 2592,78
cousnor PRODUCTS OPERATED Filed June 3, 1944 2 Sheets-Sheet 1 Filed June 3, 1944 W 9 1956 c. K. NEWCOMBE 2562 878 COMBUSTION PRODUCTS OPERATED TURBINE 2 Sheets-Sheet 2 Patented Apr. 4, 1950 COMBUSTION PRODUCTS OPERATED TURBINE Clare Kenzie Newcombe, Fleet, England, assignor to Heat Pumps Limited, London, England, a
British company Application June 3, 1944, Serial No. 538,655 In Great Britain February 23, 1943 Section 1, Public Law 690, August 8, 1946 Patent expires February 23, 1963 1 Claim.
This invention is for improvements in or relating to internal combustion turbine engines.
It is well known that the thermal eiliciency depends to a great extent on the temperature of the Working fluid as it enters the blade passages.
This temperature is chosen to be the highest which the blade material is able to withstand successfully for continuous operation. The temperature of the gases leaving the combustion chamber when normal oil-burner air-fuel ratios are used is too high for modern blade materials. It is usual, therefore, to employ some type of cooling. One such method is the use of an excess air quantity which must be compressed to the same pressure as the combustion air. This method is thermodynamically unsatisfactory, as the operating temperature drop is reduced and extra work is required to compress the excess air. It has been proposed to use engines of a high thermodynamic efficiency to drive the air is carried out in the actual combustion chamber and then discharged as high pressure exhaust gas to the turbine. The systems of the former type have the disadvantage that the compressor engine must be of nearly the same output as the turbine. The gas generator types have the disadvantage that the high temperature gases must pass through the working cylinder which must therefore have a very large swept volume for high output. Furthermore, in both types a great quantity of heat is rejected in the exhaust gases of the turibne, exhausting to atmosphere.
According to the present invention an internal combustion turbine plant comprises an air-compressor delivering compressed air to a combustion chamber wherein fuel is burnt in the compressed air, a jet-type compressor using the products of combustion from the combustion chamber as motive fluid to induce and compress a generally greater quantity of secondary air or gas, thus raising the temperature level of this induced fluid by the process of heat pumping,
heat in the exhaust gases is recovered by heat pumping.
According to a further feature of this invention a waste-heat boiler heated by th exhaust gases from the turbine may be provided to generate vapour for a second jet compressor which employs the said vapour as motive fluid to precompress air and deliver it to the main air compressor so that waste heat in the turbine exhaust gases is recovered, the vapour being so selected that it may be condensed in the compressed air and extracted therefrom to return to the boiler.
Some examples according to the invention will now be described with reference to the accompanying drawings, which are purely diagrammatic and in which- Figures 1, 2 and 3 show respectively the general layout according to the three examples.
In the first example the apparatus comprises a motor compressor unit consisting oi. an opposed piston two-stroke Diesel engine 5 coupled by beams 6 to an opposed piston air compressor 1, the whole forming a double beam engine. If desired, the apparatus may include several motor compressor units of this type connected together by rocking arms synchronised by means of cranks. High pressure air from the compressor 1 is led by a pipe 8 to a combustion chamber 9 in which fuel, such as oil fuel, is burnt. The products of combustion, which are at a high pressure and may have a greater temperature than is permissible in the turbine blade passages, are directed from the chamber 9, through a conduit ID, to the power nozzle ll of a jet-type compressor or heat pump, indicated generally by the reference numeral [2. The jet compressor consists, in combination with the nozzle l I, of an entraining chamber l3 into which the nozzle extends, an inlet It to the entraining chamber and a diffuser [5 which communicates by way of a throat IS with the entraining chamber immediately opposite the nozzle I l and which extends to a tail pipe ll. The motive fluid passing through the jet II is expanded and entrains secondary air through the inlet M. The mix ture is compressed and passed to a gas turbine l8. Waste heat may be recovered from this turbine by passing some of its exhaust gases through a conduit I!) to the inlet M of the entraining chamber of the jet compressor. Instead of a single-stage jet compressor a multi-stage unit may be employed. If desired, some of the motive fluid may be used to drive a jet vacuum pump (not shown) to draw oil. the boundary layer from the walls of the compressor diffuser l5.
In the second example (Figure 2) the plant consists of a highly supercharged two-stroke Diesel engine 2!! driving a multi-stage air compressor 2 I. The Diesel engine 20 has two blowers, namely a scavenge blower 5| and a turbo-supercharger 22, both of which may be operated by waste heat recovered from the exhaust of the Diesel engine and from the cylinder jacket cooling system. For the purpose of recovering the waste heat in the exhaust gases a boiler 23 is pro- 3 vided. The heat extracted from the exhaust gases may be added by means or a heat pump (not shown).
The engine driven compressor 2| discharges the high pressure air at three different pressure levels 24, 25, 28 to separate combustion chambers 21, 28, 29 respectively. Fuel is burnt in each ucts of combustion being passed to a jet compressor 42 in which secondary air in entrained. As before, the compressed gases are delivered as motive fluid to a gas turbine 44. In this example waste heat is not recovered directly from the exhaust gases of the turbine 44 (i. e. by leading the gases back to the suction side of the jet pump 42) but is recovered indirectl by means of a waste heat boiler 45 in which power vapour, e. g. steam, is generated and led to an auxiliary jet compressor 46 and from thence into the air compressor 40. The motivevapour is cooled by the air entering the compressor and is condensed. It can then be extracted from the mixture stream it this has been given a suitable rotary motion as found in turbines by means or the diflerence in centrifugal force due to the difference in air stream and condensed motive vapour density.
An internal combustion turbine plant comprising an air compressor delivering compressed air to a combustion chamber wherein fuel is burnt in the compressed air, a jet-type compressor using the products of combustion from the combustion chamber as motive fluid to induce and compress secondary gas and mix it with the products of combustion to lower their temperature, a gas turbine driven by the mixture from the jet compressor, a waste heat boiler heated by the exhaust gases from the turbine and arranged to generate pressure vapor, and a secondary jet compressor employing said vapor as motive fluid to precompress air and deliver it to the air compressor.
CLARE KENZIE NEWCOMBE.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date ,777,097 Lasley Sept. 30, 1930 1,854,615 Lasley Apr. 19, 1932 1,857,556 Lasley May 10, 1932 2,056,198 Lasley Oct. 6, 1936 2,096,184 Lasley Oct. 19, 1937 2,131,047 Holzwarth Sept. 27, 1938 ,025 Couzinet Mar. 26, 1940 2,280,447 Pearce Apr. 21, 1942 2,303,381 New Dec. 1, 1942