Patent Publication Number: US-2018038280-A1

Title: Turbomachine comprising a heat management system

Description:
RELATED APPLICATION 
     This application claims priority to French patent application 1657541 filed Aug. 3, 2016, the entirety of which is incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to an aircraft turbomachine comprising a heat management system, and particularly to an aircraft comprising at least one such turbomachine. 
     PRIOR ART 
       FIG. 1  shows a turbomachine  10  of an aircraft. The turbomachine  10  is equipped with a heat management system  50  of the prior art. The heat management system  50  makes it possible to manage the heat energy of the propulsion unit comprising the turbomachine  10 , the nacelle  11  and the other systems of the propulsion unit, taking excess heat in order to redistribute it to those systems which require heat in order to provide a function, by means of the circulation of a heat transfer fluid. 
     In particular, part of the heat energy is used to control the temperature of fluids (engine oil, electrical generator, hydraulic fluid, air-conditioning), structures (engine turbine, air intake lip and leading edge of the wings for anti-icing) and systems (valves, electronics, actuators, pumps etc.). 
     The majority of this portion of the heat energy is then lost for the engine thrust. 
     The turbomachine  10  comprises: a fan  12  designed to generate a flow of air in the turbomachine  10  in a direction of movement  13  of the air in the turbomachine  10 , where, as is known, the flow of air then moves downstream from the fan  12 ; a set of compressors  14  downstream of the fan  12 ; a combustion chamber  16  downstream of the set of compressors  14 , and a set of turbines  18  downstream of the combustion chamber  16 . 
     The heat management system  50  generally comprises: a first heat exchanger  51 ; a second heat exchanger  52 , and a third heat exchanger  53 . 
     The heat management system  50  also comprises a hot air line  54  which takes hot air from the primary flow of the set of compressors  14  and transports it, for example, to the nacelle  11  in order to de-ice the latter. This air is expelled to the outside and is therefore lost. 
     The turbomachine  10  also comprises a supply line  55  which supplies the combustion chamber  16  with fuel. 
     The turbomachine  10  also comprises a transfer line  56  with which it is possible to circulate hot oil from the engine, in particular from the set of compressors  14 , towards the first  51  and third  53  heat exchangers, and then back into the engine, in particular into the set of turbines  18 . 
     The first heat exchanger  51  provides an exchange of heat between the fuel in the supply line  55  and the oil in the transfer line  56  in order to heat the fuel using the heat given off by the oil, and thus cool the latter. 
     The third heat exchanger  53  provides an exchange of heat between the oil in the transfer line  56  and the air in a first air line  57  which takes air from the secondary flow of the turbomachine  10  and discharges it to the outside or to the secondary flow. With this third heat exchanger  53  it is possible to complete the cooling of the oil. 
     The heat management system  50  also comprises an air-conditioning system  58  which takes air from the primary flow, generally at the intermediate and final stages of the set of compressors  14 . To that end, the air-conditioning system  58  comprises a first line  59  which takes the air from the intermediate stage and a second line  60  which takes the air from the final stage. The first line  59  and second line  60  meet upstream of the second heat exchanger  52  and emerge from the second heat exchanger  52  to supply the air-conditioning system for the cabin of the aircraft. 
     The second heat exchanger  52  provides an exchange of heat between, on one hand, the air of the first line  59  and the second line  60  and, on the other hand, the air of a second air line  61  which takes air from the secondary flow of the turbomachine  10  and discharges it to the outside or to the secondary flow. With this second heat exchanger  52  it is possible to cool the air from the first line  59  and the second line  60 . 
     Although such an installation is quite satisfactory, it does imply an increase in drag, and therefore higher fuel consumption. 
     SUMMARY OF THE INVENTION 
     A turbomachine has been invented and is disclosed here having a heat management system with which it is possible to reduce drag, and which permits better management of the fluid flows in the turbomachine. 
     To that end, an embodiment of the invention is a dual-flow turbomachine for an aircraft, comprising a nacelle forming an air inlet lip, a set of compressors, a combustion chamber, a set of turbines, a supply line supplying fuel to the combustion chamber, a transfer line which circulates oil from the set of compressors to the set of turbines, a de-icing circuit for the air inlet lip, and a heat management system comprising: 
     (i) a first heat exchanger providing an exchange of heat between the fuel in the supply line and the oil in the transfer line, 
     (ii) a loop comprising a main line and a pump which is designed to circulate a heat transfer fluid in the main line, where the main line is connected to the outlet of the pump and enters an inlet of a third heat exchanger, where at the outlet of the third heat exchanger the main line meets an inlet of the de-icing circuit, where at the outlet of the de-icing circuit the main line meets the inlet of the pump, and where the third heat exchanger provides an exchange of heat between the heat transfer fluid of the main line and the oil of the transfer line leaving the first heat exchanger. 
     This particular arrangement permits better management of the anti-icing at the air intake lip. 
     Advantageously, the heat management system comprises: 
     (i) a first three-way valve arranged upstream of the inlet of the third heat exchanger and a first divert line arranged between the first valve and the main line, downstream of the outlet of the third heat exchanger, and/or 
     (ii) a second three-way valve arranged upstream of the inlet to the de-icing circuit and a second divert line arranged between the second valve and the main line, downstream of the outlet of the de-icing circuit. 
     The heat management system may further comprise a fourth heat exchanger arranged on the main line between the outlet of the de-icing circuit and the inlet of the pump, and the fourth heat exchanger provides an exchange of heat between the heat transfer fluid in the main line and the air of a first air line which takes air from the secondary flow of the turbomachine and discharges it to the outside or to the secondary flow. 
     The heat management system may further comprise a third three-way valve arranged upstream of the inlet of the fourth heat exchanger and a third divert line arranged between the third valve and the main line, downstream of the outlet of the fourth heat exchanger. 
     The heat management system may further comprise an air-conditioning system which takes air from the primary flow of the set of compressors, via a first and a second line which supply an air-conditioning system of the aircraft, a second heat exchanger providing an exchange of heat between, on one hand, the air of the first line and the second line and, on the other hand, the heat transfer fluid of the main line, and the second heat exchanger is arranged on the main line between the outlet of the third heat exchanger and the inlet of the de-icing circuit. 
     The heat management system may further comprise a fourth three-way valve arranged upstream of the inlet of the second heat exchanger and a fourth divert line arranged between the fourth valve and the main line, downstream of the outlet of the second heat exchanger. 
     The invention may be embodied in an aircraft comprising at least one turbomachine according to one of the preceding variants. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the invention mentioned above, and others, will become clearer upon reading the following description of an exemplary embodiment, this description being provided in relation to the appended drawings in which: 
         FIG. 1  is a schematic representation of an aircraft turbomachine equipped with a prior art heat management system; 
         FIG. 2  is a side view of an aircraft comprising a turbomachine; 
         FIG. 3  is a schematic representation of an aircraft turbomachine equipped with a heat management system according to a first embodiment of the invention; 
         FIG. 4  is a schematic representation of an aircraft turbomachine equipped with a heat management system according to a second embodiment of the invention, and 
         FIG. 5  is a schematic representation of a controller which manages a heat management system according to the invention. 
     
    
    
     DETAILED DISCLOSURE OF EMBODIMENTS 
       FIG. 2  shows an aircraft  200  equipped with a dual-flow turbomachine  202  according to the invention. The dual-flow turbomachine may be a turbofan including a fan and a gas turbine engine, e.g., jet engine. 
       FIG. 3  shows a turbomachine  30  equipped with a heat management system  300  according to a first embodiment of the invention, and  FIG. 4  shows a turbomachine  40  equipped with a heat management system  400  according to a second embodiment of the invention. Each heat management system  300 ,  400  is intended to manage the distribution of heat between the various fluids in the turbomachine  30 ,  40 . 
     The turbomachine  30 ,  40  comprises a nacelle  11  which forms, at the front, an air intake lip via which the air enters the turbomachine  30 ,  40 . At the air intake lip, the nacelle  11  is equipped with a de-icing circuit  310 ,  410  for the air intake lip. 
     The turbomachine  30 ,  40  comprises elements in common with the turbomachine  1  of  FIG. 1 , in particular a gas turbine having a fan  12 , a set of compressors  14 , a combustion chamber  16 , a set of turbines  18 , a supply line  55  for supplying the fuel to the combustion chamber  16 , a transfer line  56  for circulating hot oil from the set of compressors  14  to the set of turbines  18 . These elements are provided with the same references. The fan  12  generates a flow of air in the turbomachine  30 ,  40  in a direction of movement  13  of the air in the turbomachine  30 ,  40 . 
     Among the elements in common with the heat management system  50  of the prior art, the heat management system  300 ,  400  according to the invention comprises a first heat exchanger  51  which provides an exchange of heat between the fuel in the supply line  55  and the oil in the transfer line  56  in order to heat the fuel using the heat given off by the oil, and cool the latter. 
     The heat management system  300 ,  400  according to the invention comprises a loop  302 ,  402  in which circulates a heat transfer fluid. 
     The loop  302 ,  402  comprises a main line  306 ,  406  and a pump  304 ,  404  which is designed to circulate the heat transfer fluid in the main line  306 ,  406 . 
     The main line  306 ,  406  is connected to the outlet of the pump  304 ,  404  and enters an inlet of a third heat exchanger  308 ,  408 . On leaving the third heat exchanger  308 ,  408 , the main line  306 ,  406  meets an inlet of the de-icing circuit  310 ,  410 . At the outlet of the de-icing circuit  310 ,  410 , the main line  306 ,  406  meets the inlet of the pump  304 ,  404 . 
     The third heat exchanger  308 ,  408  provides an exchange of heat between the heat transfer fluid of the main line  306 ,  406  and the oil of the transfer line  56  leaving the first heat exchanger  51 . 
     Thus, any heat of the engine oil transported in the transfer line  56  which has not been dissipated in the fuel of the supply line  55  is transferred to the heat transfer fluid of the loop  302 ,  402  via the third heat exchanger  308 ,  408 . The heat transfer fluid heated in this manner then meets the de-icing circuit  310 ,  410  of the air intake lip, thus providing the de-icing function and allowing the heat transfer fluid to cool down. 
     A heat management system  300 ,  400  of this type distributes heat to those systems which need it, and the heat is not converted into another form of energy, making it possible to eliminate both the losses linked to that transformation and the mass of the associated systems. The heat management system  300 ,  400  minimizes wastage of ambient air which is drawn in by the engine but is not used for propulsion by limiting the number of air/air heat exchangers or air/fluid heat exchangers whose sole objective is to extract heat which is put to little or no use, and minimizes bleeding from the engine, and the anti-icing system, which is used only very sporadically, serves as a heat exchanger for regulating the temperature of the heat transfer fluid. 
     In order to compensate for the loss of efficacy of the heat exchanger constituted by the de-icing circuit  310 ,  410  of the air intake lip when the aircraft  200  is not moving or is at low speed, the heat management system  300 ,  400  comprises a fourth heat exchanger  312 ,  412  which is arranged on the main line  306 ,  406  between the outlet of the de-icing circuit  310 ,  410  and the inlet of the pump  304 ,  404 . 
     The fourth heat exchanger  312 ,  412  provides an exchange of heat between the heat transfer fluid in the main line  306 ,  406  and the air of a first air line  314 ,  414  which takes air from the secondary flow of the turbomachine  30 ,  40  and discharges it to the outside or into the secondary flow. 
     The heat management system  300 ,  400  comprises an air-conditioning system  58  which takes air from the primary flow of the set of compressors  14 , and it comprises, to that end, a first line  59  which takes the air from the intermediate stage of the set of compressors  14  and a second line  60  which takes the air from the final stage of the set of compressors  14 . The first line  59  and second line  60  meet upstream of the second heat exchanger  52  and emerge from the second heat exchanger  52  to supply the air-conditioning system for the cabin of the aircraft. 
     In the first embodiment of the invention, shown in  FIG. 3 , the second heat exchanger  52  provides an exchange of heat between, on one hand, the air of the first line  59  and the second line  60  and, on the other hand, the air of a second air line  61  which takes air from the secondary flow of the turbomachine  20  and discharges it to the outside or to the secondary flow. 
     In the first embodiment of the invention, shown in  FIG. 4 , the second heat exchanger  52  provides an exchange of heat between, on one hand, the air of the first line  59  and the second line  60  and, on the other hand, the heat transfer fluid in the main line  406 . The second heat exchanger  52  is arranged on the main line  406 , between the outlet of the third heat exchanger  408  and the inlet of the de-icing circuit,  410 . The second heat exchanger  52  is the pre-cooler for the air-conditioning system. 
     In order to best manage the heat management of the heat management system  300 ,  400 , that is to say whether or not to use a certain element present along the main line  306 ,  406 , the heat management system  300 ,  400  comprises divert lines which are hydraulically connected to the main line  306 ,  406 , in parallel with said elements. 
     At the intersection between a divert line and the main line  306 ,  406 , upstream of said element, there is arranged a remote-controlled three-way valve. 
     To that end, the heat management system  300 ,  400  comprises a controller  350 ,  450  which commands each three-way valve to open or to close individually depending on parameters of various sensors. The sensors are for example temperature sensors measuring the temperatures of the various fluids of the turbomachine  30 ,  40 , or pressure sensors. 
     Thus, the heat management system  300 ,  400  permits dynamic and integrated management of the heat, avoiding heavy storage systems. 
       FIG. 5  shows a controller  500  which comprises, connected by a communication bus  510 : a processor or CPU (“central processing unit”)  501 , RAM (“random access memory”)  502 , ROM (“read-only memory”)  503 , a storage unit such as a hard disk or a storage support reader such as an SD (“secure digital”) card reader  504 , and at least one communication interface  505  by means of which for example the controller  500  can communicate with the various three-way valves and the sensors. 
     The processor can execute instructions sent to the RAM from the ROM, from an external memory (not shown), from a storage support (such as an SD card), or from a communication network. When the equipment is energized, the processor is able to read instructions from the RAM and execute these. 
     The heat management system  300 ,  400  comprises at least one three-way valve and the following associated divert line: 
     for the first and second embodiments of the invention: 
     a first three-way valve  352 ,  452  arranged upstream of the inlet of the third heat exchanger  308 ,  408  and a first divert line  353 ,  453  arranged between the first valve  352 ,  452  and the main line  306 ,  406 , downstream of the outlet of the third heat exchanger  308 ,  408 , and/or 
     a second three-way valve  354 ,  454  arranged upstream of the inlet to the de-icing circuit  310 ,  410  and a second divert line  355 ,  455  arranged between the second valve  354 ,  454  and the main line  306 ,  406 , downstream of the outlet of the de-icing circuit  310 ,  410 , and/or 
     when the fourth heat exchanger  312 ,  412  is present: 
     a third three-way valve  356 ,  456  arranged upstream of the inlet of the fourth heat exchanger  312 ,  412  and a third divert line  357 ,  457  arranged between the third valve  356 ,  456  and the main line  306 ,  406 , downstream of the outlet of the fourth heat exchanger  312 ,  412 , and/or 
     for the second embodiment of the invention: 
     a fourth three-way valve  458  arranged upstream of the inlet of the second heat exchanger  52  and a fourth divert line  459  arranged between the fourth valve  458  and the main line  406 , downstream of the outlet of the second heat exchanger  52 . 
     An example of operation is described herein below. 
     The source of heat is in this case the engine oil which serves to lubricate the bearings of the engine and the gearbox. 
     The temperature of the engine oil must be kept around 100° C. where it enters the engine. The heat is extracted from the engine oil by the first heat exchanger  51  between the oil and the fuel. This first heat exchanger  51  is used as long as the outgoing fuel does not exceed a certain temperature, approximately 150° C. The residual excess heat is extracted from the engine oil by the third heat exchanger  308 ,  408  between the oil and the heat transfer fluid. 
     The heat transfer fluid heated in this manner passes some or all of its heat on to the air intake lip for anti-icing. 
     The heat exchangers are for example of the compact plate/fin or surface exchanger type. 
     In the second embodiment of the invention, the pre-cooler  52  of the air conditioning system  58  has been integrated into the loop  402 , but it is possible to integrate heat exchangers of other systems of the aircraft  200 , such as those for the electrical generators. 
     It is also possible to use the loop  302 ,  402  to control the temperature of the hydraulic fluid leaving the pump, by adding an exchanger between the hydraulic fluid and the heat transfer fluid of the loop  302 ,  402 . 
     This loop  302 ,  402  can also be used to provide control of the turbine casings, by routing it around the casings. 
     Systems such as the air bleed valves can also be temperature-controlled using the loop  302 ,  402 . 
     It is most useful when all of the hot and cold sources of the propulsion unit are connected by the loop  302 ,  402 . 
     It is also possible to integrate, into the loop  302 ,  402 , the cooling of the oil of the electrical generators, which in current configurations is cooled by a compact exchanger or a surface exchanger whose cold source is the air of the fan flow, possibly combined with compact exchangers placed on the engine oil and/or fuel circuits. 
     It is also possible to use this same loop to control the temperature of the hydraulic fluid by adding an exchanger between the hydraulic fluid and the heat transfer fluid of the fluid loop. 
     The loop can also be used to provide temperature control of the (low-pressure and high-pressure) casings of the set of turbines, by routing the main line  306 ,  406  around the casings. 
     Systems such as the air bleed valves can also be temperature-controlled using the loop. It is most useful when all of the hot and cold sources of the propulsion unit are connected by the fluid loop. 
     An embodiment of the invention is dual-flow turbomachine ( 30 ,  40 ) for an aircraft ( 200 ), comprising a nacelle ( 11 ) forming an air inlet lip, a set of compressors ( 14 ), a combustion chamber ( 16 ), a set of turbines ( 18 ), a supply line ( 55 ) supplying fuel to the combustion chamber ( 16 ), a transfer line ( 56 ) which circulates oil from the set of compressors ( 14 ) to the set of turbines ( 18 ), a de-icing circuit ( 310 ,  410 ) for the air inlet lip, and a heat management system ( 300 ,  400 ) comprising: a first heat exchanger ( 51 ) providing an exchange of heat between the fuel in the supply line ( 55 ) and the oil in the transfer line ( 56 ), a loop ( 302 ,  402 ) comprising a main line ( 306 ,  406 ) and a pump ( 304 ,  404 ) which is designed to circulate a heat transfer fluid in the main line ( 306 ,  406 ), where the main line ( 306 ,  406 ) is connected to the outlet of the pump ( 304 ,  404 ) and enters an inlet of a third heat exchanger ( 308 ,  408 ), where at the outlet of the third heat exchanger ( 308 ,  408 ) the main line ( 306 ,  406 ) meets an inlet of the de-icing circuit ( 310 ,  410 ), where at the outlet of the de-icing circuit ( 310 ,  410 ) the main line ( 306 ,  406 ) meets the inlet of the pump ( 304 ,  404 ), and where the third heat exchanger ( 308 ,  408 ) provides an exchange of heat between the heat transfer fluid of the main line ( 306 ,  406 ) and the oil of the transfer line ( 56 ) leaving the first heat exchanger ( 51 ). 
     The heat management system ( 300 ,  400 ) comprises: a first three-way valve ( 352 ,  452 ) arranged upstream of the inlet of the third heat exchanger ( 308 ,  408 ) and a first divert line ( 353 ,  453 ) arranged between the first valve ( 352 ,  452 ) and the main line ( 306 ,  406 ), downstream of the outlet of the third heat exchanger ( 308 ,  408 ), and/or a second three-way valve ( 354 ,  454 ) arranged upstream of the inlet to the de-icing circuit ( 310 ,  410 ) and a second divert line ( 355 ,  455 ) arranged between the second valve ( 354 ,  454 ) and the main line ( 306 ,  406 ), downstream of the outlet of the de-icing circuit ( 310 ,  410 ). 
     The heat management system ( 300 ,  400 ) may comprise a fourth heat exchanger ( 312 ,  412 ) arranged on the main line ( 306 ,  406 ) between the outlet of the de-icing circuit ( 310 ,  410 ) and the inlet of the pump ( 304 ,  404 ), and in that the fourth heat exchanger ( 312 ,  412 ) provides an exchange of heat between the heat transfer fluid in the main line ( 306 ,  406 ) and the air of a first air line ( 314 ,  414 ) which takes air from the secondary flow of the turbomachine ( 30 ,  40 ) and discharges it to the outside or to the secondary flow. 
     The heat management system ( 300 ,  400 ) may comprise a third three-way valve ( 356 ,  456 ) arranged upstream of the inlet of the fourth heat exchanger ( 312 ,  412 ) and a third divert line ( 357 ,  457 ) arranged between the third valve ( 356 ,  456 ) and the main line ( 306 ,  406 ), downstream of the outlet of the fourth heat exchanger ( 312 ,  412 ). 
     The heat management system ( 400 ) may comprise an air-conditioning system ( 58 ) which takes air from the primary flow of the set of compressors ( 14 ), via a first ( 59 ) and a second ( 60 ) line which supply an air-conditioning system of the aircraft, a second heat exchanger ( 52 ) providing an exchange of heat between, on one hand, the air of the first line ( 59 ) and the second line ( 60 ) and, on the other hand, the heat transfer fluid of the main line ( 406 ), and in that the second heat exchanger ( 52 ) is arranged on the main line ( 406 ) between the outlet of the third heat exchanger ( 408 ) and the inlet of the de-icing circuit ( 410 ). 
     The heat management system ( 400 ) may comprise a fourth three-way valve ( 458 ) arranged upstream of the inlet of the second heat exchanger ( 52 ) and a fourth divert line ( 459 ) arranged between the fourth valve ( 458 ) and the main line ( 406 ), downstream of the outlet of the second heat exchanger ( 52 ). 
     While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.