Turbine power generation system capable of achieving high-enthalpy ram air cascade cooling

Abstract

The invention belongs to the technical field of aero-engine thermal management, and provides a turbine power generation system for realizing high-enthalpy ram air cascade cooling, which comprises a first-stage heat exchanger, a second-stage heat exchanger, an oil-gas turbine, an air turbine and a diverter valve, a hot side inlet of the first-stage heat exchanger is connected with the high-temperature and high-pressure air channel; a hot side outlet of the first-stage heat exchanger is connected with a hot side inlet of the second-stage heat exchanger; a hot side outlet of the secondary heat exchanger is connected with an inlet of the air turbine; an outlet of the air turbine is connected with an inlet of the diverter valve; an outlet of the flow dividing valve is connected with a cold side inlet of the second-stage heat exchanger. An inlet of the oil-gas turbine is connected with a cracked oil-gas pipeline; an outlet of the oil-gas turbine is connected with a cold side inlet of the first-stage heat exchanger. High-temperature and high-pressure air is cooled through low-temperature cracking gas obtained after expansion cooling of the oil gas turbine and low-temperature and low-pressure air obtained after expansion cooling of the air turbine in sequence, and the situation that the air turbine fails or is damaged due to the high-temperature environment is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of thermal management of aviation engines, and in particular to a turbine power generation system for realizing high-enthalpy ram air step cooling. Background Art

[0002] With the continuous development of aerospace technology, humans have put forward higher and higher requirements for the wide-range flight performance of aircraft. Supersonic aircraft with high flight Mach number, high energy supply power, long flight time and long distance flight will play a great strategic role in future international games. The maximum flight speed of traditional turbojet engines is difficult to break through Mach 3, and the scramjet engine that can work at more than Mach 7 cannot provide sufficient thrust below Mach 3. Therefore, the combination engine based on turbine engine and ramjet engine has received more and more attention. Since the ramjet engine uses the high-speed flight ramjet of the engine to compress the air and does not use a compression system with rotatable blades, it is impossible to extract shaft work from the rotating shaft and cannot generate electricity. Therefore, using the high-speed incoming flow of the aircraft during high-speed flight to drive the air turbine to expand and work and then drive the generator to generate electricity has become one of the options. While flying at a high Mach number, the stagnation temperature of the incoming air also rises sharply. The stagnation temperature of the aircraft flying at a speed of Mach 7 reaches 1900K. The ultra-high stagnation temperature brings extremely high heat load to the air turbine.

[0003] Under the current material temperature resistance, the maximum temperature resistance of non-cooled blades is about 1200K. Therefore, when the total temperature of the incoming air exceeds 1200K, in order to ensure the long-term stable operation of the air turbine power generation device, the incoming high-enthalpy ram air must be pre-cooled. However, in hypersonic flight, there is no cooling air as a heat sink, and the available fuel heat sink is very limited. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present invention is to provide a turbine power generation system that realizes high-enthalpy ram air step cooling, by sequentially utilizing the low-temperature cracked gas after expansion and cooling of the oil and gas turbine and the low-temperature low-pressure air after expansion and cooling of the air turbine to cool the high-temperature and high-pressure air, thereby preventing the air turbine from failing or being damaged due to the high-temperature environment.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A turbine power generation system for realizing high-enthalpy ram air step cooling, comprising: a primary heat exchanger, a secondary heat exchanger, an oil and gas turbine, an air turbine and a diverter valve;

[0007] The hot side inlet of the primary heat exchanger is connected to the high-temperature and high-pressure air channel; the hot side outlet of the primary heat exchanger is connected to the hot side inlet of the secondary heat exchanger; the hot side outlet of the secondary heat exchanger is connected to the inlet of the air turbine; the outlet of the air turbine is connected to the inlet of the diverter valve; the outlet of the diverter valve is connected to the cold side inlet of the secondary heat exchanger; the inlet of the oil and gas turbine is connected to the cracking oil and gas pipeline; the outlet of the oil and gas turbine is connected to the cold side inlet of the primary heat exchanger;

[0008] The oil and gas turbine is used to expand and cool the hydrocarbon fuel cracking gas transported by the cracking oil and gas pipeline to obtain low-temperature cracking gas; the first-level heat exchanger is used to use the low-temperature cracking gas to release heat and cool the high-enthalpy ram air transported by the high-temperature and high-pressure air channel when the temperature of the high-temperature and high-pressure air is greater than the set value to obtain primary cooling air; the second-level heat exchanger is used to use the low-temperature and low-pressure air transported by the diverter valve to release heat and cool the primary cooling air to obtain secondary cooling air; the air turbine is used to expand and cool the secondary cooling air to obtain the low-temperature and low-pressure air; the diverter valve is used to divert the low-temperature and low-pressure air.

[0009] Preferably, the set value is 1200K.

[0010] Preferably, the oil and gas turbine is an axial flow turbine or a radial flow turbine.

[0011] Preferably, the ram air turbine is an axial flow turbine or a radial flow turbine.

[0012] Preferably, the primary heat exchanger and the secondary heat exchanger are both shell and tube heat exchangers.

[0013] Preferably, the calculation formula for the oil and gas mass flow rate of the oil and gas turbine is: m1=P1 / △i1 / η1; the calculation formula for the air mass flow rate of the air turbine is: m2=P2 / △i2 / η2; wherein, m1 is the oil and gas mass flow rate; P1 is the power generation power of the oil and gas turbine; △i1 is the total enthalpy difference between the inlet and outlet of the oil and gas turbine; η1 is the power generation efficiency of the oil and gas turbine; m2 is the air mass flow rate; P2 is the power generation power of the air turbine; △i2 is the total enthalpy difference between the inlet and outlet of the air turbine; η2 is the power generation efficiency of the air turbine.

[0014] Preferably, the calculation formula for the hot side outlet enthalpy of the primary heat exchanger includes: and Q1=m1·c p ·△t; where H2 is the hot side outlet enthalpy of the primary heat exchanger; H1 is the enthalpy value of the high temperature and high pressure air; Q1 is the heat transfer capacity of the primary heat exchanger; c pis the specific heat of oil and gas at constant pressure; △t is the temperature rise of the oil and gas on the cold side of the first-stage heat exchanger.

[0015] Preferably, the calculation formula for the cold side outlet enthalpy of the secondary heat exchanger includes: And Q2=m2·(H2-H3); wherein, H5 is the cold side outlet enthalpy of the secondary heat exchanger; H4 is the outlet enthalpy of the air turbine; Q2 is the heat transfer capacity of the secondary heat exchanger; k is the diversion ratio of the diverter valve; H3 is the hot side outlet enthalpy of the secondary heat exchanger.

[0016] The present invention discloses the following technical effects:

[0017] The present invention provides a turbine power generation system that realizes high-enthalpy ram air step cooling. The high-temperature and high-pressure air is cooled by sequentially utilizing the low-temperature cracked gas after expansion and cooling of the oil and gas turbine and the low-temperature and low-pressure air after expansion and cooling of the air turbine. This solves the problem of excessive temperature of non-cooled blades of the air turbine caused by the stagnation temperature during high Mach speed flight, and achieves the goal of avoiding failure or damage of the air turbine due to a high-temperature environment by cooling the incoming high-enthalpy ram air twice. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0019] Figure 1 A schematic diagram of the structure of a turbine power generation system provided by an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of operating data of a turbine power generation system provided by an embodiment of the present invention;

[0021] Description of reference numerals:

[0022] 1-Oil and gas turbine, 2-Primary heat exchanger, 3-Air turbine, 4-Secondary heat exchanger, 5-Diverter valve. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The purpose of the present invention is to provide a turbine power generation system that realizes high-enthalpy ram air step cooling, by sequentially utilizing the low-temperature cracked gas after expansion and cooling of the oil and gas turbine and the low-temperature low-pressure air after expansion and cooling of the air turbine to cool the high-temperature and high-pressure air, thereby preventing the air turbine from failing or being damaged due to the high-temperature environment.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Figure 1 A schematic diagram of the structure of a turbine power generation system provided in an embodiment of the present invention is shown in FIG. Figure 1 As shown, the present invention provides a turbine power generation system for realizing high enthalpy ram air step cooling, comprising: a primary heat exchanger 2, a secondary heat exchanger 4, an oil and gas turbine 1, an air turbine 3 and a diverter valve 5;

[0027] The hot side inlet of the primary heat exchanger 2 is connected to the high-temperature and high-pressure air channel; the hot side outlet of the primary heat exchanger 2 is connected to the hot side inlet of the secondary heat exchanger 4; the hot side outlet of the secondary heat exchanger 4 is connected to the inlet of the air turbine 3; the outlet of the air turbine 3 is connected to the inlet of the diverter valve 5; the outlet of the diverter valve 5 is connected to the cold side inlet of the secondary heat exchanger 4; the inlet of the oil and gas turbine 1 is connected to the cracking oil and gas pipeline; the outlet of the oil and gas turbine 1 is connected to the cold side inlet of the primary heat exchanger 2;

[0028] The oil and gas turbine 1 is used to expand and cool the cracked gas of hydrocarbon fuel transported by the cracked oil and gas pipeline to obtain low-temperature cracked gas; the first-stage heat exchanger 2 is used to use the low-temperature cracked gas to release heat and cool the high-enthalpy ram air transported by the high-temperature and high-pressure air channel when the temperature of the high-temperature and high-pressure air is greater than the set value to obtain primary cooled air; the second-stage heat exchanger 4 is used to use the low-temperature and low-pressure air transported by the diverter valve 5 to release heat and cool the primary cooled air to obtain secondary cooled air; the air turbine 3 is used to expand and cool the secondary cooled air to obtain low-temperature and low-pressure air; the diverter valve 5 is used to divert the low-temperature and low-pressure air.

[0029] Optionally, the set value is 1200K.

[0030] Preferably, the oil and gas turbine 1 is an axial flow turbine or a radial flow turbine.

[0031] Optionally, the ram air turbine 3 is an axial flow turbine or a radial flow turbine.

[0032] Preferably, both the primary heat exchanger 2 and the secondary heat exchanger 4 are shell and tube heat exchangers.

[0033] Specifically, the calculation formula for the oil and gas mass flow rate of the oil and gas turbine 1 is: m1=P1 / △i1 / η1; the calculation formula for the air mass flow rate of the air turbine 3 is: m2=P2 / △i2 / η2; wherein, m1 is the oil and gas mass flow rate; P1 is the power generation power of the oil and gas turbine 1; △i1 is the total enthalpy difference between the inlet and outlet of the oil and gas turbine 1; η1 is the power generation efficiency of the oil and gas turbine 1; m2 is the air mass flow rate; P2 is the power generation power of the air turbine 3; △i2 is the total enthalpy difference between the inlet and outlet of the air turbine 3; η2 is the power generation efficiency of the air turbine 3.

[0034] Furthermore, the calculation formula for the hot side outlet enthalpy of the first-stage heat exchanger 2 includes: and Q1=m1·c p ·△t; where H2 is the hot side outlet enthalpy of the first stage heat exchanger 2; H1 is the enthalpy value of high temperature and high pressure air; Q1 is the heat transfer capacity of the first stage heat exchanger 2; c p is the specific heat of oil and gas at constant pressure; △t is the temperature rise of oil and gas on the cold side of the first-stage heat exchanger 2.

[0035] Specifically, the calculation formula for the cold side outlet enthalpy of the secondary heat exchanger 4 includes: And Q2=m2·(H2-H3); wherein, H5 is the cold side outlet enthalpy of the secondary heat exchanger 4; H4 is the outlet enthalpy of the air turbine 3; Q2 is the heat exchange capacity of the secondary heat exchanger 4; k is the diversion ratio of the diverter valve 5; H3 is the hot side outlet enthalpy of the secondary heat exchanger 4.

[0036] refer to Figure 2 The high-enthalpy ram air step-cooled turbine power generation system requires the calculation of the system's thermal parameters. The known calculation conditions are: the incoming high-enthalpy ram air temperature is 1825K and the pressure is 500kPa; the oil and gas turbine 1 inlet temperature is 1000K and the pressure is 5.6Mpa; the oil and gas turbine 1 outlet pressure is 2.6Mpa; the oil and gas turbine 1 power generation efficiency is 0.7; the oil and gas turbine 1 power generation capacity is 80kW; the oil temperature on the cold side of the first-stage heat exchanger 2 rises by 100K; the air turbine 3 inlet temperature is 580K and the pressure is 500kPa; the air turbine 3 outlet pressure is 20kPa; the air turbine 3 power generation efficiency is 0.7; the air turbine 3 power generation capacity is 100kW, and the diversion ratio of the diverter valve 5 is 0.8.

[0037] Specifically, the total enthalpy difference between the inlet and outlet of the oil and gas turbine 1 during the isentropic expansion process can be calculated based on the inlet temperature and pressure of the oil and gas turbine 1 and the outlet pressure of the oil and gas turbine 1, and the oil and gas mass flow rate can be calculated based on the power generation efficiency and power generation of the oil and gas turbine 1. The total enthalpy difference between the inlet and outlet of the air turbine 3 during the isentropic expansion process can be calculated based on the inlet temperature and pressure of the air turbine 3 and the outlet pressure of the air turbine 3, and the air mass flow rate can be calculated based on the power generation efficiency and power generation of the air turbine 3. The outlet temperature of the air turbine 3 is 373.57K. m1 is 0.83kg / s and m2 is 0.413kg / s.

[0038] Furthermore, the heat transfer capacity of the first-stage heat exchanger 2 is obtained according to the oil and gas mass flow rate, the temperature rise of the oil and gas on the cold side of the first-stage heat exchanger 2, and the constant-pressure specific heat of the oil and gas. The corresponding enthalpy can be found according to the temperature and pressure of the incoming high-enthalpy ram air. The outlet enthalpy of the hot side of the first-stage heat exchanger 2 can be obtained by combining the air mass flow rate and the heat transfer capacity of the first-stage heat exchanger 2. Then, the outlet temperature of the hot side of the first-stage heat exchanger 2 is found to be 1208K.

[0039] Specifically, the heat transfer capacity of the secondary heat exchanger 4 can be obtained according to the hot side outlet temperature of the first-stage heat exchanger 2, the inlet temperature of the air turbine 3, and the air mass flow rate. The corresponding enthalpy can be found according to the outlet temperature and pressure of the air turbine 3. The cold side outlet enthalpy of the secondary heat exchanger 4 can be found in combination with the air mass flow rate, the diversion ratio of the diverter valve 5, and the heat transfer capacity of the secondary heat exchanger 4. Then, the cold side outlet temperature of the secondary heat exchanger 4 is found to be 1178K.

[0040] The beneficial effects of the present invention are as follows:

[0041] The present invention cools down the high-temperature and high-pressure air by sequentially utilizing the low-temperature cracked gas after expansion and cooling of the oil and gas turbine and the low-temperature and low-pressure air after expansion and cooling of the air turbine, thereby avoiding failure or damage of the air turbine due to the high-temperature environment.

[0042] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0043] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A turbine power generation system that realizes high enthalpy ram air step cooling, It is characterized in that include: Primary heat exchanger, secondary heat exchanger, oil and gas turbine, air turbine and diverter valve; The hot side inlet of the primary heat exchanger is connected to the high-temperature and high-pressure air channel; the hot side outlet of the primary heat exchanger is connected to the hot side inlet of the secondary heat exchanger; the hot side outlet of the secondary heat exchanger is connected to the inlet of the air turbine; the outlet of the air turbine is connected to the inlet of the diverter valve; the outlet of the diverter valve is connected to the cold side inlet of the secondary heat exchanger; the inlet of the oil and gas turbine is connected to the cracking oil and gas pipeline; the outlet of the oil and gas turbine is connected to the cold side inlet of the primary heat exchanger; The oil and gas turbine is used to expand and cool the hydrocarbon fuel cracking gas transported by the cracking oil and gas pipeline to obtain low-temperature cracking gas; the first-level heat exchanger is used to use the low-temperature cracking gas to release heat and cool the high-enthalpy ram air transported by the high-temperature and high-pressure air channel when the temperature of the high-temperature and high-pressure air is greater than the set value to obtain primary cooling air; the second-level heat exchanger is used to use the low-temperature and low-pressure air transported by the diverter valve to release heat and cool the primary cooling air to obtain secondary cooling air; the air turbine is used to expand and cool the secondary cooling air to obtain the low-temperature and low-pressure air; the diverter valve is used to divert the low-temperature and low-pressure air.

2. A turbine power generation system for realizing high enthalpy ram air step cooling according to claim 1, It is characterized in that The set value is 1200K.

3. A turbine power generation system for realizing high enthalpy ram air step cooling according to claim 1, It is characterized in that The oil-gas turbine is an axial-flow turbine or a radial-flow turbine.

4. A turbine power generation system for realizing high enthalpy ram air step cooling according to claim 1, It is characterized in that The ram air turbine is an axial flow turbine or a radial flow turbine.

5. A turbine power generation system for realizing high enthalpy ram air step cooling according to claim 1, It is characterized in that The primary heat exchanger and the secondary heat exchanger are both shell and tube heat exchangers.

6. A turbine power generation system for realizing high enthalpy ram air step cooling according to claim 1, It is characterized in that The calculation formula of the oil and gas mass flow rate of the oil and gas turbine is: m 1 =P 1 / △i 1 / η 1 The air mass flow rate of the air turbine is calculated as follows: m 2 =P 2 / △i 2 / η 2 ; Among them, m 1 is the oil and gas mass flow rate; P 1 is the power generation power of the oil and gas turbine; △i 1 is the total enthalpy difference between the inlet and outlet of the oil and gas turbine; η 1 is the power generation efficiency of the oil and gas turbine; m 2 is the air mass flow rate; P 2 is the power generation capacity of the air turbine; △i 2 is the total enthalpy difference between the inlet and outlet of the air turbine; η 2 is the power generation efficiency of the air turbine.

7. A turbine power generation system for realizing high enthalpy ram air step cooling according to claim 6, It is characterized in that The calculation formula of the hot side outlet enthalpy of the first-stage heat exchanger includes: and Q 1 =m 1 ·c p ·△t; where H 2 is the hot side outlet enthalpy of the first stage heat exchanger; H 1 is the enthalpy value of the high temperature and high pressure air; Q 1 is the heat exchange capacity of the primary heat exchanger; p is the specific heat of oil and gas at constant pressure; △t is the temperature rise of the oil and gas on the cold side of the first-stage heat exchanger.

8. A turbine power generation system for realizing high enthalpy ram air step cooling according to claim 6, It is characterized in that The calculation formula for the cold side outlet enthalpy of the secondary heat exchanger includes: and Q 2 =m 2 ·(H 2 -H 3 ), where H 5 is the cold side outlet enthalpy of the secondary heat exchanger; H 4 is the outlet enthalpy of the air turbine; Q 2 is the heat transfer capacity of the secondary heat exchanger; k is the diversion ratio of the diversion valve; H 3 is the hot side outlet enthalpy of the secondary heat exchanger.

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