Waste heat power generation system

Abstract

The invention discloses a waste heat power generation system. The system comprises a turbo expander; one side of the condenser is communicated with the heat exchanger and the evaporator, and the other side of the condenser is communicated with a cold source; one side of the evaporator is communicated with the turbo expander and the heat exchanger, and the other side of the evaporator is communicated with a heat source; the heat exchanger is provided with a first pipeline between the turbo expander and the condenser, the heat exchanger is provided with a second pipeline between the condenser and the evaporator, and the first pipeline and the second pipeline exchange heat at the position of the heat exchanger. The heat exchanger is arranged between the turbo expander and the condenser, so that a high-temperature gaseous working medium discharged by the turbo expander and a high-pressure low-temperature liquid working medium discharged by the condenser are preheated at the heat exchanger, the temperature of the working medium entering the evaporator can be increased, and the power generation efficiency can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of waste heat power generation, and in particular to a medium- and low-temperature waste heat magnetic suspension ORC power generation system. Background Art

[0002] The Organic Rankine Cycle (ORC) is a Rankine cycle that uses low-boiling-point organic matter as the working fluid. It is mainly used to generate electricity from medium and low-temperature heat sources (<150°C), such as medium and low-temperature geothermal energy, industrial waste gas, etc.

[0003] In the relevant technologies, in view of the limitations of process, equipment, technology, and investment return, the development of the waste heat recovery power generation market is focused on the high-grade waste heat (>250℃) field. Single-pressure, dual-pressure, and flash evaporation processes are used to drive steam turbines to generate electricity. Given that the technology of high-grade waste heat recovery power generation projects is relatively mature and the investment return is high, the competition in this field is extremely fierce. In the field of medium- and high-grade waste heat (150~250℃), due to technical limitations, the screw ORC power generation process is generally used. This process uses vaporized organic working fluid water to drive the screw expander to generate electricity. This process has high maintenance costs and low power generation efficiency, so the market application is relatively small. At present, low-grade heat sources cannot be effectively recycled, resulting in waste of heat sources and even environmental pollution. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a waste heat power generation system, in which a heat exchanger is arranged between a turbine expander and a condenser, so that the high-temperature gaseous working medium discharged from the turbine expander is preheated at the heat exchanger with the high-pressure and low-temperature liquid working medium discharged from the condenser, thereby increasing the temperature of the working medium entering the evaporator, thereby effectively improving the power generation efficiency.

[0005] According to an embodiment of the present invention, the waste heat power generation system includes: a turbine expander; a condenser, one side of the condenser is connected to the turbine expander and the heat exchanger; an evaporator, one side of the evaporator is connected to the turbine expander and the condenser, and the other side is connected to a heat source; a heat exchanger, the heat exchanger is arranged between the turbine expander and the condenser, the heat exchanger is provided with a first pipeline between the turbine expander and the condenser, and a second pipeline is provided between the evaporator and the condenser, and the first pipeline and the second pipeline exchange heat at the heat exchanger.

[0006] In the waste heat power generation system according to an embodiment of the present invention, a heat exchanger is arranged between the turbine expander and the condenser, so that the high-temperature gaseous working fluid discharged from the turbine expander is preheated at the heat exchanger with the high-pressure and low-temperature liquid working fluid discharged from the condenser, thereby increasing the temperature of the working fluid entering the evaporator, thereby effectively improving the power generation efficiency.

[0007] According to some embodiments of the present invention, the waste heat power generation system further includes: a first liquid pump, which is arranged between the condenser and the evaporator, and is used to drive the working medium circulation.

[0008] According to some embodiments of the present invention, a first pressure sensor is provided on the second pipeline, and the first pressure sensor is electrically connected to the first liquid pump; and / or a first temperature sensor is provided on the second pipeline, and the first temperature sensor is electrically connected to the first liquid pump.

[0009] According to some embodiments of the present invention, the waste heat power generation system further includes: a gas-liquid separator, and the gas-liquid separator is arranged between the condenser and the first liquid pump.

[0010] According to some embodiments of the present invention, the waste heat power generation system further includes: a pressure relief branch, one end of which is connected to the outlet of the evaporator and the other end of which is connected to the inlet of the condenser.

[0011] According to some embodiments of the present invention, a first control valve is provided on the pressure relief branch, and a second control valve is provided at the inlet of the turbine expander, and the first control valve and the second control valve selectively control the inlet flow and pressure of the turbine expander.

[0012] According to some embodiments of the present invention, a second pressure sensor is provided on the pressure relief branch, and the second pressure sensor is electrically connected to the first control valve and the second control valve; and / or a second temperature sensor is provided on the pressure relief branch, and the second temperature sensor is electrically connected to the first control valve and the second control valve.

[0013] According to some embodiments of the present invention, the waste heat power generation system further includes: a cooling unit, wherein the cooling unit is disposed on the other side of the condenser, and the cooling unit is used to cool the condenser.

[0014] According to some embodiments of the present invention, the cooling unit includes: a cooling tower and a second liquid pump, wherein the second liquid pump is disposed between the condenser and the cooling tower, and the second liquid pump is used to drive the coolant to circulate between the condenser and the cooling tower.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 Schematic diagram of the structure of a waste heat power generation system according to an embodiment of the present invention.

[0017] Reference numerals: 100. Waste heat power generation system; 1. Turbine expander; 2. Condenser; 3. Evaporator; 4. Heat exchanger; 5. First liquid pump; 6. First pressure sensor; 7. First temperature sensor; 8. Gas-liquid separator; 9. First control valve; 10. Second control valve; 11. Second pressure sensor; 12. Second temperature sensor; 13. Cooling tower; 14. Second liquid pump. DETAILED DESCRIPTION

[0018] Embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Embodiments of the present invention are described in detail below.

[0019] Reference below Figure 1 A waste heat power generation system 100 according to an embodiment of the present invention is described.

[0020] The waste heat power generation system 100 of the embodiment of the present invention includes: a turbine expander 1; a condenser 2, one side of the condenser 2 is connected to the turbine expander 1 and the heat exchanger 4; an evaporator 3, one side of the evaporator 3 is connected to the turbine expander 1 and the condenser 2, and the other side is connected to the heat source; a heat exchanger 4, the heat exchanger 4 is arranged between the turbine expander 1 and the condenser 2, a first pipeline is arranged between the turbine expander 1 and the condenser 2, a second pipeline is arranged between the evaporator 3 and the condenser 2, and the first pipeline and the second pipeline exchange heat at the heat exchanger 4.

[0021] That is, a heat exchanger 4 is provided between the turbine expander 1 and the condenser 2, so that the high-temperature gaseous working fluid discharged from the turbine expander 1 is preheated at the heat exchanger 4 and the high-pressure and low-temperature liquid working fluid discharged from the condenser 2, thereby increasing the temperature of the working fluid entering the evaporator 3, thereby effectively improving the power generation efficiency.

[0022] The circulating working fluid uses R245fa (pentafluoropropane), and the system can maintain a high power generation efficiency within the range of 85℃-150℃. In addition, since R245fa is corrosive to organic matter, all the sealing gaskets in the system need to use lead gaskets, and the heat exchanger 4, condenser 2 and evaporator 3 should use brazed plate heat exchangers; Furthermore, the turbine expander 1 adopts a magnetically suspended turbine expander 1 with an integrated impeller, motor and rotor design, a simple structure, no mechanical contact, low maintenance cost and high power generation efficiency.

[0023] Therefore, a heat exchanger 4 is arranged between the turbine expander 1 and the condenser 2, so that the high-temperature gaseous working medium discharged from the turbine expander 1 can be preheated at the heat exchanger 4 and the high-pressure and low-temperature liquid working medium discharged from the condenser 2, thereby increasing the temperature of the working medium entering the evaporator 3, thereby effectively improving the power generation efficiency.

[0024] The waste heat power generation system 100 further includes: a first liquid pump 5, which is arranged between the condenser 2 and the evaporator 3, and is used to drive the working medium to circulate. That is, the first liquid pump 5 is arranged between the condenser 2 and the evaporator 3, and the first liquid pump 5 can drive the liquid working medium to flow from the condenser 2 to the evaporator 3, so that the liquid working medium evaporates and becomes gaseous at the evaporator 3.

[0025] Furthermore, the frequency of the first liquid pump 5 can also be controlled, so as to achieve a better power generation effect according to the state of the working medium.

[0026] Among them, the second pipeline is provided with a first pressure sensor 6, and the first pressure sensor 6 is electrically connected to the first liquid pump 5. That is to say, the first pressure sensor 6 that can monitor the pressure of the working fluid is provided on the second pipeline, so that the frequency of the first liquid pump 5 can be controlled by the pressure of the working fluid in the second pipeline. For example, when the pressure of the working fluid in the second pipeline is high, the frequency of the first liquid pump 5 can be reduced, so that the working fluid has a higher power generation efficiency in the turbine expander 1.

[0027] The second pipeline is provided with a first temperature sensor 7, and the first temperature sensor 7 is electrically connected to the first liquid pump 5. That is, the first temperature sensor 7 that can monitor the temperature of the working medium is provided on the second pipeline, so that the frequency of the first liquid pump 5 can be controlled by the temperature of the working medium in the second pipeline. For example, when the temperature of the working medium in the second pipeline is high, the frequency of the first liquid pump 5 can be reduced, so that the working medium has a higher power generation efficiency in the turbine expander 1.

[0028] In addition, the waste heat power generation system 100 further includes: a gas-liquid separator 8, which is arranged between the condenser 2 and the first liquid pump 5. That is, the gas-liquid separator 8 can separate the gaseous working medium from the liquid working medium, which can prevent the gaseous working medium from entering the first liquid pump 5 on the one hand, and on the other hand, the liquid working medium can exchange heat with the gaseous working medium discharged from the turbine expander 1 at the heat exchanger 4.

[0029] In addition, the waste heat power generation system 100 further includes: a pressure relief branch, one end of which is connected to the outlet of the evaporator 3 and the other end of which is connected to the inlet of the condenser 2. That is, when the temperature and pressure of the working fluid discharged from the evaporator 3 are relatively high, in order to protect the turbine expander 1 and improve the power generation efficiency of the turbine expander 1, part or all of the working fluid can be discharged to the condenser 2 through the pressure relief branch.

[0030] Among them, a first control valve 9 is provided on the pressure relief branch, and a second control valve 10 is provided on the inlet of the turbine expander 1. The first control valve 9 and the second control valve 10 selectively control the inlet flow and pressure of the turbine expander 1. In other words, the inlet flow and pressure of the turbine expander 1 can be jointly adjusted by providing the first control valve 9 and the second control valve 10.

[0031] A second pressure sensor 11 is provided on the pressure relief branch, and the second pressure sensor 11 is electrically connected to the first control valve 9 and the second control valve 10. That is to say, a second pressure sensor 11 that can monitor the pressure of the working fluid is provided on the pressure relief branch, so that the opening of the first control valve 9 and the second control valve 10 can be controlled by the pressure of the working fluid in the second pipeline. For example, when the working fluid pressure in the pressure relief branch is high, the first control valve 9 is opened, and the second control valve 10 is closed, so that the working fluid with a higher pressure flows back to the condenser 2 through the first control valve 9. Of course, it is also possible to reduce the opening of the second control valve 10 so that part of the excess high-pressure working fluid enters the turbine expander 1 for power generation, and the other part flows back to the condenser 2 through the first control valve 9.

[0032] A second temperature sensor 12 is provided on the pressure relief branch, and the second temperature sensor 12 is electrically connected to the first control valve 9 and the second control valve 10. That is to say, a second temperature sensor 12 that can monitor the temperature of the working fluid is provided on the pressure relief branch, so that the opening of the first control valve 9 and the second control valve 10 can be controlled by the temperature of the working fluid in the second pipeline. For example, when the temperature of the working fluid in the pressure relief branch is high, the first control valve 9 is opened, and the second control valve 10 is closed, so that the working fluid with a higher temperature flows back to the condenser 2 through the first control valve 9. Of course, it is also possible to reduce the opening of the second control valve 10 so that a part of the excess high-temperature working fluid enters the turbine expander 1 for power generation, and the other part flows back to the condenser 2 through the first control valve 9.

[0033] In addition, the waste heat power generation system 100 also includes: a cooling unit, which is arranged on the other side of the condenser 2, and the cooling unit is used to cool the condenser 2. That is, by setting the cooling unit, the condenser 2 can be cooled. That is, the gaseous working medium generates electricity after entering the turbine expander 1, and the outlet of the turbine expander 1 flows out the gaseous-liquid two-phase working medium, and the gaseous working medium can release heat and condense at the condenser 2, so that the gaseous working medium condenses into a liquid state, and then can repeatedly enter the evaporator 3 to evaporate and absorb heat. In this way, the heat of the condenser 2 is dissipated by the external cooling unit, so that the effective heat dissipation of the condenser 2 can be achieved.

[0034] Further, the cooling unit includes: a cooling tower 13 and a second liquid pump 14, the second liquid pump 14 is arranged between the condenser 2 and the cooling tower 13, and the second liquid pump 14 is used to drive the coolant to circulate between the condenser 2 and the cooling tower 13. In other words, the cooling tower 13 can provide low-temperature coolant, so as to cool the condenser 2. And, the second liquid pump 14 can drive the coolant to circulate between the condenser 2 and the cooling tower 13, so that the coolant releases heat at the cooling tower 13 and absorbs heat at the condenser 2.

[0035] Thus, the working mode of the waste heat power generation system 100 of the embodiment of the present invention is as follows: The liquid working medium is heated at equal pressure in the evaporator 3 to become a high-temperature and high-pressure gaseous working medium; The gaseous working medium undergoes adiabatic expansion through the turbine expander 1 to perform work, and the temperature and pressure of the working medium decrease; Thermal energy is converted into mechanical energy, driving the generator to output electricity.

[0036] The gaseous working medium preheats the high-pressure and low-temperature liquid working medium through the heat exchanger 4, and the temperature of the gaseous working medium decreases; The excess pressure or flow of the gaseous working fluid enters the condenser 2 through the bypass pipe; The gaseous working medium is cooled down by isobaric pressure in condenser 2 and becomes a low-temperature and low-pressure liquid working medium; The pressure of the liquid working medium increases through adiabatic compression by the first liquid pump 5, and drives the working medium to circulate; The liquid working medium pre-cools the high-temperature gaseous working medium through the intermediate heat exchanger 4, and the temperature thereof increases.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0038] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0039] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A waste heat power generation system, characterized in that: include: Turbo expander (1); A condenser (2), one side of the condenser (2) being in communication with the heat exchanger (4) and the evaporator (3); an evaporator (3), one side of the evaporator (3) being connected to the turbine expander (1) and the heat exchanger (4), and the other side of the evaporator (3) being connected to a heat source; A heat exchanger (4), the heat exchanger (4) being arranged between the turbine expander (1) and the condenser (2), the heat exchanger (4) being provided with a first pipeline between the turbine expander (1) and the condenser (2), and a second pipeline being provided between the evaporator (3) and the condenser (2), the first pipeline and the second pipeline exchanging heat at the heat exchanger (4).

2. The waste heat power generation system according to claim 1, characterized in that: Also includes: A first liquid pump (5), the first liquid pump (5) is arranged between the condenser (2) and the evaporator (3), and the liquid pump is used to drive the circulation of the working medium.

3. The waste heat power generation system according to claim 2, characterized in that: A first pressure sensor (6) is provided on the second pipeline, and the first pressure sensor (6) is electrically connected to the first liquid pump (5); and / or, A first temperature sensor (7) is provided on the second pipeline, and the first temperature sensor (7) is electrically connected to the first liquid pump (5).

4. The waste heat power generation system according to claim 1, characterized in that: Also includes: A gas-liquid separator (8), wherein the gas-liquid separator (8) is arranged between the condenser (2) and the first liquid pump (5).

5. The waste heat power generation system according to claim 1, characterized in that: Also includes: A pressure relief branch, one end of which is connected to the outlet of the evaporator (3) and the other end of which is connected to the inlet of the condenser (2).

6. The waste heat power generation system according to claim 5, characterized in that: A first control valve (9) is provided on the pressure relief branch, and a second control valve (10) is provided at the inlet of the turbine expander (1). The first control valve (9) and the second control valve (10) selectively control the inlet flow and pressure of the turbine expander (1).

7. The waste heat power generation system according to claim 6, characterized in that: A second pressure sensor (11) is provided on the pressure relief branch, and the second pressure sensor (11) is electrically connected to the first control valve (9) and the second control valve (10); and / or, A second temperature sensor (12) is provided on the pressure relief branch, and the second temperature sensor (12) is electrically connected to the first control valve (9) and the second control valve (10).

8. The waste heat power generation system according to claim 1, characterized in that: Also includes: A cooling unit, wherein the cooling unit is arranged on the other side of the condenser (2), and the cooling unit is used to cool the condenser (2).

9. The waste heat power generation system according to claim 8, characterized in that: The cooling unit comprises: a cooling tower (13) and a second liquid pump (14), wherein the second liquid pump (14) is arranged between the condenser (2) and the cooling tower (13), and the second liquid pump (14) is used to drive the cooling liquid to circulate between the condenser (2) and the cooling tower (13).

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