Waste heat power generation system

Abstract

The utility model relates to the technical field of waste heat recovery, in particular to a waste heat power generation system. The waste heat power generation system comprises an ORC power generation device and an absorption type heat pump device which both utilize waste heat as a driving heat source so as to improve the heat source utilization rate. The ORC power generation device is provided with a first circulation loop and a first condenser, the heat pump device is provided with a second circulation loop and a second evaporator, and a third circulation loop for circulation of a heat exchange medium is arranged between the first condenser and the second evaporator; and a heat exchange medium in the third circulation loop can exchange heat with the refrigerant in the second circulation loop at the second evaporator and exchange heat with the organic working medium in the first circulation loop at the first condenser, so that the cooling capacity of the refrigerant is transferred to the organic working medium through the heat exchange medium. Refrigerant of the heat pump device is used for providing cooling capacity for the ORC power generation device, the cooling effect of the organic working medium can be better, and therefore the power generation efficiency can be improved, and medium and low temperature waste heat can be used for power generation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste heat recovery, in particular to a waste heat power generation system. BACKGROUND

[0002] With the increasingly severe global energy problem, the recovery and reuse of industrial waste heat has become an important way to improve energy efficiency, reduce energy waste, reduce production cost and reduce environmental pollution; the industrial field consumes a huge amount of energy, and the waste heat resource is abundant; according to statistics, the waste heat resource in the industrial field accounts for about 30% of the total energy consumption, among which the utilization rate of medium and low temperature waste heat is low due to the characteristics of low grade and scattered distribution.

[0003] Organic Rankine cycle (ORC) is a technology for effectively recovering medium and low temperature waste heat; in the prior art, a cold heat and power triple generation mode combining ORC and absorption refrigeration system is usually adopted: high temperature hot water is produced by a waste heat auxiliary boiler to supply life heating and supply the ORC power generation system, and the absorption refrigeration system is used to provide life cooling, and the produced cooling water is used to cool the ORC. However, this technical scheme has the following defects: (1) the waste heat is only used as an auxiliary heat source for the ORC system, and the waste heat utilization rate is low; (2) the absorption refrigeration system mainly provides high-grade chilled water for life cooling, and provides low-grade cooling water to improve the organic Rankine cycle (ORC) power generation efficiency, but the improvement space is limited; (3) the waste heat in the boiler is only an auxiliary heat source, and the main heat source relies on fossil fuels, resulting in high carbon emission intensity, which is contrary to the demand for clean energy transformation. CONTENT OF THE UTILITY MODEL

[0004] The utility model aims at providing a waste heat power generation system to improve the waste heat utilization rate and improve the power generation efficiency to some extent.

[0005] The utility model provides a waste heat power generation system, which comprises an ORC power generation device and a heat pump device.

[0006] The heat pump device is an absorption heat pump, and the heat pump device and the ORC power generation device both utilize waste heat as a driving heat source.

[0007] The ORC power generation device has a first circulation loop, and the ORC power generation device comprises a first condenser, which is used for condensing organic working medium in the first circulation loop.

[0008] The heat pump device has a second circulation loop, and the heat pump device comprises a second evaporator, which is used for vaporizing refrigerant in the second circulation loop.

[0009] A third circulation loop is arranged between the first condenser and the second evaporator for circulating a heat transfer medium to transfer the cold energy of the refrigerant to the organic working fluid by means of the heat transfer medium.

[0010] Further, the third circulation loop comprises a second heat exchange channel and a fourth heat exchange channel, the second heat exchange channel and the fourth heat exchange channel being in communication with each other to form a closed loop.

[0011] The second heat exchange channel is arranged in the first condenser to exchange heat between the heat transfer medium flowing through the second heat exchange channel and the organic working fluid flowing through the first condenser.

[0012] The fourth heat exchange channel is arranged in the second evaporator to exchange heat between the heat transfer medium flowing through the fourth heat exchange channel and the refrigerant flowing through the second evaporator.

[0013] Further, the ORC power generation device further comprises a first evaporator, an expander and a working fluid pump.

[0014] The first evaporator, the expander, the first condenser and the working fluid pump are sequentially connected to form the first circulation loop.

[0015] The first evaporator is provided with a first heat exchange channel for flowing the heat medium carrying residual heat to heat the organic working fluid flowing through the first evaporator by means of the residual heat.

[0016] Further, the heat pump device comprises a generator, a second condenser and an absorber.

[0017] The generator, the second condenser, the second evaporator and the absorber are sequentially connected to form the second circulation loop.

[0018] The generator is provided with a third heat exchange channel for flowing the heat medium carrying residual heat to vaporize the refrigerant in the generator by means of the residual heat.

[0019] Further, a circulating pump is arranged on the third circulation loop.

[0020] Further, the residual heat power generation system further comprises a residual heat recovery device.

[0021] The residual heat recovery device comprises a heat source channel and a heat medium channel which can exchange heat with each other, the heat source channel being used for flowing the heat source carrying residual heat, and the heat medium channel being used for flowing the heat medium.

[0022] The outlet of the heat medium channel is connected with the inlet of the first heat exchange channel and the inlet of the third heat exchange channel respectively, and the inlet of the heat medium channel is connected with the outlet of the first heat exchange channel and the outlet of the third heat exchange channel respectively.

[0023] Further, the outlet and / or the inlet of the heat medium channel is provided with a three-way regulating valve to be connected with the first heat exchange channel and the third heat exchange channel respectively through the three-way regulating valve.

[0024] Further, the outlet or the inlet of the heat medium channel is connected with a heat pump.

[0025] Further, a first branch is arranged on the outlet header of the heat medium channel, the first branch is arranged in parallel with the inlet pipeline of the heat source channel, and a first valve is arranged on the first branch.

[0026] Further, a second branch is arranged on the inlet header of the heat medium channel, the second branch is arranged in parallel with the outlet pipeline of the heat source channel, and a second valve is arranged on the second branch.

[0027] Compared with the prior art, the utility model has the beneficial effects that:

[0028] The waste heat power generation system comprises an ORC power generation device and a heat pump device.

[0029] The ORC power generation device is used for generating power by using waste heat as a driving heat source, and the ORC power generation device has a first circulation loop for circulating flow of an organic working medium, and the ORC power generation device comprises a first condenser for condensing the organic working medium in the first circulation loop. The heat pump device is an absorption heat pump, and the heat pump device has a second circulation loop, and the heat pump device also uses waste heat as a driving heat source, so that low-boiling-point refrigerant in a binary solution in the heat pump device is vaporized by heat and circulates in the second circulation loop.

[0030] A third circulation loop is arranged between the first condenser and the second evaporator, and the inside of the first circulation loop is used for circulating flow of a heat exchange medium. In the second evaporator, the heat exchange medium in the third circulation loop can exchange heat with the refrigerant to absorb the cold quantity released by the refrigerant and vaporize the refrigerant; and in the first condenser, the heat exchange medium in the third circulation loop can transfer the cold quantity absorbed from the second evaporator to the organic working medium to condense the organic working medium in the first condenser by using the cold quantity released by the refrigerant.

[0031] Therefore, both the ORC power generation device and the absorption heat pump device in this application can absorb waste heat to use it as a driving heat source, thereby improving the waste heat utilization rate. At the same time, the ways to improve the power generation efficiency of the ORC power generation device usually include increasing the high-temperature source temperature and decreasing the low-temperature source temperature. This application uses the refrigerant of the absorption heat pump to provide cooling capacity to the ORC power generation device through the third circulation loop, so that the organic working fluid of the ORC power generation device has a better cooling effect at the first condenser, thereby improving the power generation efficiency and enabling the ORC power generation device to generate electricity using medium and low temperature waste heat. At the same time, it avoids using a boiler to provide a driving heat source for the ORC power generation device, reducing environmental pollution. Attached Figure Description

[0032] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0033] Fig. 1 A schematic diagram of the waste heat power generation system provided in this embodiment of the utility model;

[0034] Fig. 2 A schematic diagram of a waste heat power generation system including a waste heat recovery device is provided for an embodiment of this utility model.

[0035] Fig. 3 A schematic diagram of a waste heat power generation system including another waste heat recovery device, provided for an embodiment of this utility model.

[0036] Figure label:

[0037] 1-ORC power generation unit, 11-first evaporator, 12-expander, 13-generator, 14-first condenser, 15-working fluid pump;

[0038] 2-Heat pump unit, 21-Generator, 22-Second condenser, 23-Second evaporator, 24-Absorber;

[0039] 3-Waste heat recovery device, 31-Heat source channel, 32-Heat medium channel, 33-Heat pump, 34-First branch, 35-Second branch, 36-Three-way regulating valve;

[0040] 4-Third circulation loop, 41-Circulation pump. Detailed Implementation

[0041] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are some but not all of the embodiments of the present application.

[0042] The components of the embodiments of the present application generally described and shown in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application.

[0043] Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0044] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0045] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0046] The following refers to Figs. 1 to 3 A waste heat power generation system is described according to some embodiments of the present application.

[0047] The present application provides a waste heat power generation system, as shown in Fig. 1 The waste heat power generation system includes an ORC power generation device 1 and a heat pump device 2.

[0048] The ORC power generation device 1 is used for generating power by using waste heat as driving heat source; specifically, the ORC power generation device 1 comprises a first evaporator 11, an expander 12, a first condenser 14 and a working medium pump 15, which are sequentially connected to form a first circulation loop for circulating organic working medium, i.e. the working medium outlet of the first evaporator 11 is connected to the working medium inlet of the expander 12, the working medium outlet of the expander 12 is connected to the working medium inlet of the first condenser 14, and the working medium outlet of the first condenser 14 is connected to the working medium inlet of the first evaporator 11 through the working medium pump 15, so as to form the first circulation loop for circulating organic working medium.

[0049] The first evaporator 11 is used for heating the organic working medium flowing therethrough by using waste heat as driving heat source, so as to make the organic working medium absorb heat and vaporize; the expander 12 is connected with a generator 13, and the organic working medium after absorbing heat and vaporizing can enter the expander 12 to do work, so as to drive the generator 13 to generate power; the first condenser 14 is used for condensing the working medium after doing work, so as to make the working medium condense into liquid state, and then sent back to the first evaporator 11 through the working medium pump 15, so as to absorb heat again and start a new cycle, so as to continuously convert the heat energy of waste heat into electric energy by using the circulation of organic working medium.

[0050] The heat pump device 2 is an absorption heat pump, and the heat pump device 2 also uses waste heat as driving heat source, so that the low-boiling-point refrigerant in the binary solution in the heat pump device 2 is heated and vaporized and circulated among the components of the heat pump device 2. Specifically, the heat pump device 2 comprises a generator 21, a second condenser 22, a second evaporator 23 and an absorber 24, which are sequentially connected to form a second circulation loop. The binary solution exists in the generator 21 and the absorber 24, and the binary solution is composed of two substances with different boiling points, the low-boiling-point substance being refrigerant and the high-boiling-point substance being absorbent. The generator 21 is used for heating the binary solution by using waste heat as driving heat source, so as to make the low-boiling-point refrigerant in the binary solution evaporate and vaporize; the vaporized refrigerant flows into the second condenser 22, and exchanges heat with the external cooling water at the second condenser 22, so as to make the refrigerant cool and condense to form low-temperature liquid refrigerant; then the refrigerant enters the second evaporator 23 and releases cold energy at the second evaporator 23 to vaporize again; then the refrigerant enters the absorber 24 and is absorbed by the absorbent in the absorber 24, and is sent back to the generator 21 to start a new cycle.

[0051] In this embodiment, the third circulating loop 4 is arranged between the first condenser 14 and the second evaporator 23, and the inside of the third circulating loop 4 is used for circulating flow of a heat exchange medium, which can be low-temperature chilled water or low-temperature refrigerant. At the second evaporator 23, the heat exchange medium in the third circulating loop 4 can exchange heat with the refrigerant to absorb the cold released by the refrigerant and vaporize the refrigerant; at the first condenser 14, the heat exchange medium in the third circulating loop 4 can transfer the cold absorbed from the second evaporator 23 to the organic working medium to condense the organic working medium at the first condenser 14 by using the cold released by the refrigerant.

[0052] Both the ORC power generation device 1 and the absorption heat pump device 2 in the present application can absorb waste heat to use the waste heat as a driving heat source, thereby improving the waste heat utilization rate; at the same time, the approach to improve the power generation efficiency of the ORC power generation device 1 generally includes increasing the high-temperature source temperature and reducing the low-temperature source temperature, and the present application uses the refrigerant of the absorption heat pump to provide cold to the ORC power generation device 1 through the third circulating loop 4, so that the cooling effect of the organic working medium of the ORC power generation device 1 at the first condenser 14 is better, thereby improving the power generation efficiency and enabling the ORC power generation device 1 to use medium and low-temperature waste heat for power generation, while avoiding using a boiler to provide a driving heat source for the ORC power generation device 1, thereby reducing the pollution to the environment.

[0053] In one embodiment of the present application, preferably, as shown in Fig. 2 The waste heat power generation system further comprises a waste heat recovery device 3 to recover waste heat by using a heat medium and transfer the waste heat to the ORC power generation device 1 and the heat pump device 2.

[0054] The waste heat recovery device 3 is a heat exchanger, which comprises a heat source channel 31 and a heat medium channel 32 that can exchange heat with each other, the heat source channel 31 is used for flow of a heat source carrying waste heat, for example, the heat source is flue gas in industrial production, and the heat source channel 31 is connected with a flue gas discharge channel of an industrial device, so that the flue gas carrying waste heat generated in industrial production flows through the heat source channel 31 of the waste heat recovery device 3. The heat medium channel 32 is used for flow of a heat medium, so that the heat medium can exchange heat with the heat source in the heat source channel 31 to recover the waste heat carried by the heat source.

[0055] In the ORC power generation device 1, the first evaporator 11 is provided with a first heat exchange channel, the inlet of the first heat exchange channel is connected with the outlet of the heat medium channel 32, and the outlet of the first heat exchange channel is connected with the inlet of the heat medium channel 32, so that the heat medium can circulate between the first heat exchange channel and the heat medium channel 32, thereby being able to use the waste heat absorbed by the heat medium to heat the organic working medium flowing through the first heat exchanger, so as to use the waste heat as the driving heat source of the ORC power generation device 1.

[0056] In the heat pump device 2, the generator 21 is provided with a third heat exchange passage, the inlet of the third heat exchange passage is also connected with the outlet of the heat medium passage 32, and the outlet of the third heat exchange passage is also connected with the inlet of the heat medium passage 32, so that the heat medium can also flow between the third heat exchange passage and the heat medium passage 32, thereby enabling the heat absorbed by the heat medium to be used as a driving heat source to heat the binary solution in the generator 21, and enabling the refrigerant in the binary solution to be heated and vaporized.

[0057] In an embodiment of the present application, preferably, a second heat exchange passage is formed in the first condenser 14 of the ORC power generation device 1, a fourth heat exchange passage is formed in the second evaporator 23 of the heat pump device 2, the inlet of the second heat exchange passage is connected with the outlet of the fourth heat exchange passage, and the outlet of the second heat exchange passage is connected with the inlet of the fourth heat exchange passage, so that the second heat exchange passage and the fourth heat exchange passage are connected to form a closed loop, i.e., a third circulation loop 4. In the heat pump device 2, when the heat exchange medium in the third circulation loop 4 flows through the fourth heat exchange passage, the heat exchange medium can exchange heat with the refrigerant in the second evaporator 23, so that the refrigerant is vaporized and releases cold energy, and the heat exchange medium is cooled; the cooled heat exchange medium then flows to the second heat exchange passage to exchange heat with the organic working medium flowing through the first condenser 14, so as to provide cold energy to the organic working medium and cause the organic working medium to condense.

[0058] In this embodiment, preferably, when the heat exchange medium used in the third circulation loop 4 is low-temperature chilled water, a circulating pump 41 is arranged on the third circulation loop 4 outside the first condenser 14 and the second evaporator 23, so as to provide driving force for the circulation of the heat exchange medium in the third circulation loop 4.

[0059] When the heat exchange medium used in the third circulation loop 4 is low-temperature refrigerant, since the low-temperature refrigerant can provide driving force for circulation by itself, the third circulation loop 4 does not need to be provided with a circulating pump.

[0060] In an embodiment of the present application, preferably, the outlet of the heat medium passage 32 is provided with a three-way regulating valve 36, so as to connect the three-way regulating valve 36 with the first heat exchange passage and the third heat exchange passage, and thereby use the three-way regulating valve 36 to regulate the proportion of the heat medium sent to the first heat exchange passage and the third heat exchange passage.

[0061] In this embodiment, the three-way regulating valve 36 can also be arranged at the inlet of the heat medium passage 32, or three-way regulating valves 36 can be arranged at both the inlet and the outlet of the heat medium passage 32.

[0062] In an embodiment of the present application, preferably, a heat pump 33 is connected with the inlet or the outlet of the heat medium passage 32, so as to use the heat pump 33 to provide driving force for the flow of the heat medium.

[0063] In an embodiment of the present application, preferably, asFig. 3 As shown, the outlet of the heat medium passage 32 is communicated with an outlet header, one end of the outlet header is communicated with the outlet of the heat medium passage 32, and the other end of the outlet header is communicated with the inlets of the first heat exchange passage and the third heat exchange passage respectively; the outlet header is provided with a first branch 34, the first branch 34 is arranged in parallel with the inlet pipeline of the heat source passage 31 of the waste heat recovery device 3, and the first branch 34 is provided with a first valve for controlling the opening and closing of the first branch 34.

[0064] The inlet of the heat medium passage 32 is communicated with an inlet header, one end of the inlet header is communicated with the inlet of the heat medium passage 32, and the other end of the inlet header is communicated with the outlets of the first heat exchange passage and the third heat exchange passage respectively. The inlet header is provided with a second branch 35, the second branch 35 is arranged in parallel with the outlet pipeline of the heat source passage 31 of the waste heat recovery device 3, and the second branch 35 is provided with a second valve for controlling the opening and closing of the second branch 35.

[0065] Therefore, when the heat source carrying waste heat is in a gaseous or hot state, the heat source can be directly sent into the ORC power generation device 1 and the heat pump device 2 as a heat medium without passing through the waste heat recovery device 3.

[0066] In an embodiment of the present application, preferably, the organic working medium circulating in the ORC power generation device 1 is a low-boiling-point organic working medium, such as R123 (trifluorodichloroethane), R245fa (pentafluoropropane) or cyclopentane, etc.

[0067] In an embodiment of the present application, preferably, the binary solution in the heat pump device 2 is an aqueous ammonia solution or a lithium bromide aqueous solution.

[0068] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A waste heat power generation system, characterized by, The system comprises an ORC power generation device and a heat pump device; The heat pump device is an absorption heat pump, and both the heat pump device and the ORC power generation device utilize waste heat as driving heat source; The ORC power generation device has a first circulation loop, and comprises a first condenser for condensing organic working medium in the first circulation loop; The heat pump device has a second circulation loop, and comprises a second evaporator for vaporizing refrigerant in the second circulation loop; A third circulation loop is arranged between the first condenser and the second evaporator, and is used for circulating flow of heat exchange medium to transfer cold energy of the refrigerant to the organic working medium by the heat exchange medium.

2. The waste heat power generation system according to claim 1, characterized by, The third circulation loop comprises a second heat exchange passage and a fourth heat exchange passage, and the second heat exchange passage and the fourth heat exchange passage are in communication with each other to form a closed loop; The second heat exchange passage is located in the first condenser to exchange heat between the heat exchange medium flowing through the second heat exchange passage and the organic working medium flowing through the first condenser; The fourth heat exchange passage is located in the second evaporator to exchange heat between the heat exchange medium flowing through the fourth heat exchange passage and the refrigerant flowing through the second evaporator.

3. The waste heat power generation system according to claim 2, characterized by, The ORC power generation device further comprises a first evaporator, an expander and a working medium pump; The first evaporator, the expander, the first condenser and the working medium pump are sequentially connected to form the first circulation loop; The first evaporator is provided with a first heat exchange passage for flow of heat medium carrying waste heat to heat the organic working medium flowing through the first evaporator by waste heat.

4. The waste heat power generation system according to claim 3, characterized by The heat pump device comprises a generator, a second condenser and an absorber; The generator, the second condenser, the second evaporator and the absorber are sequentially connected to form the second circulation loop; The generator is provided with a third heat exchange passage for flow of the heat medium carrying waste heat to heat and vaporize the refrigerant in the generator by waste heat.

5. The waste heat power generation system of claim 1, wherein, A circulating pump is arranged on the third circulation loop.

6. The waste heat power generation system of claim 4, wherein, The waste heat power generation system further comprises a waste heat recovery device; The waste heat recovery device comprises a heat source passage and a heat medium passage which can exchange heat with each other, the heat source passage is used for flow of heat source carrying waste heat, and the heat medium passage is used for flow of the heat medium; An outlet of the heat medium passage is in communication with an inlet of the first heat exchange passage and an inlet of the third heat exchange passage respectively, and an inlet of the heat medium passage is in communication with an outlet of the first heat exchange passage and an outlet of the third heat exchange passage respectively.

7. The waste heat power generation system of claim 6, wherein, The outlet and / or the inlet of the heat medium passage is provided with a three-way regulating valve to be in communication with the first heat exchange passage and the third heat exchange passage respectively by the three-way regulating valve.

8. The waste heat power generation system of claim 6, wherein, A heat pump is in communication with the outlet or the inlet of the heat medium passage.

9. The waste heat power generation system of claim 6, wherein, A first branch is arranged on an outlet header of the heat medium passage, the first branch is arranged in parallel with an inlet pipeline of the heat source passage, and a first valve is arranged on the first branch.

10. The waste heat power generation system of claim 9, wherein, The second branch is provided on the inlet header pipe of the heat medium channel, is provided in parallel with the outlet pipeline of the heat source channel, and is provided with a second valve.

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