An organic Rankine cycle coupled with a mixed working fluid refrigeration system

Abstract

This invention relates to the field of refrigeration and discloses an organic Rankine cycle coupled with a mixed working fluid refrigeration system, which includes a low-grade heat energy pipeline, an organic Rankine cycle unit, and a mixed working fluid refrigeration cycle unit. The organic Rankine cycle unit is connected to the power system of the mounting platform through the low-grade heat energy pipeline. The waste heat generated by the power system of the mounting platform drives the organic Rankine cycle unit, and then the organic Rankine cycle unit drives the mixed working fluid refrigeration cycle unit to achieve deep refrigeration. The organic Rankine cycle unit and the mixed working fluid refrigeration cycle unit are coupled and share the same working fluid, eliminating the need for additional power supply for the refrigeration cycle. This improves the overall utilization efficiency of fuel and achieves both power supply and deep refrigeration.

Description

Technical Field

[0001] This invention relates to the field of refrigeration, and more particularly to an organic Rankine cycle coupled with a mixed working fluid refrigeration system driven by low-grade thermal energy. Background Technology

[0002] In applications such as fishing boats and island reefs, there are simultaneous needs for power supply and cooling. These applications generate a large amount of low-grade heat energy, such as engine waste heat, which can be used to generate electricity using methods like the organic Rankine cycle, improving the overall efficiency of fuel utilization. Simultaneously, absorption refrigeration cycles can be used to recover and utilize this low-grade heat energy for both power supply and cooling. However, preserving catches and other items requires low freezing temperatures. Traditional absorption refrigeration systems operate at relatively high temperatures (e.g., -10°C), making it difficult to meet the requirements for quick freezing and low-temperature preservation (e.g., -50°C) of high-end catches such as tuna. Summary of the Invention

[0003] The purpose of this invention is to provide an organic Rankine cycle coupled with a mixed working fluid refrigeration system that can effectively utilize low-grade heat energy and achieve deep refrigeration.

[0004] To achieve the above objectives, the solution provided by the present invention is as follows:

[0005] An organic Rankine cycle coupled with a mixed refrigerant refrigeration system includes a low-grade heat energy pipeline, an organic Rankine cycle unit, and a mixed refrigerant refrigeration cycle unit. The organic Rankine cycle unit includes a waste heat exchanger, an expander, a condenser, a separator, and a booster pump connected in sequence. The waste heat exchanger is connected to the low-grade heat energy pipeline. The mixed refrigerant refrigeration cycle unit includes a compressor, an aftercooler, a regenerative heat exchanger, a throttling element, an evaporator, and the separator. The compressor, aftercooler, regenerative heat exchanger, throttling element, and evaporator are connected in sequence. The evaporator is connected to the separator through the regenerative heat exchanger. The liquid phase outlet of the separator is connected to the booster pump, and the gas phase outlet of the separator is connected to the compressor. A mixed refrigerant circulates in both the organic Rankine cycle unit and the mixed refrigerant refrigeration cycle unit. The mixed refrigerant expands in the expander to drive the compressor.

[0006] Preferably, the expander drives the compressor via mechanical transmission.

[0007] Preferably, a gas phase buffer tank is provided between the separator and the compressor.

[0008] Preferably, the organic Rankine cycle unit further includes a preheater, which is disposed between the booster pump and the waste heat exchanger, and the expander is connected to the condenser through the preheater.

[0009] Preferably, the mixed working fluid refrigeration cycle unit further includes a compression heat recovery unit, which is disposed between the compressor and the aftercooler, and the booster pump is connected to the waste heat exchanger through the compression heat recovery unit.

[0010] Preferably, the mixed working fluid refrigeration cycle unit further includes an intermediate stage regenerator and a liquid throttling element. The intermediate stage regenerator is disposed between the regenerating heat exchanger and the separator, and the aftercooler is connected to the regenerating heat exchanger through the intermediate stage regenerator. The liquid throttling element is disposed between the booster pump and the intermediate stage regenerator.

[0011] Preferably, the mixed working fluid refrigeration cycle unit further includes an intermediate stage regenerator and a liquid throttling element. The intermediate stage regenerator is disposed between the regenerating heat exchanger and the separator, and the aftercooler is connected to the regenerating heat exchanger through the intermediate stage regenerator. The booster pump is connected to the liquid throttling element through the intermediate stage regenerator, and the outlet of the liquid throttling element is connected to the intermediate stage regenerator.

[0012] Preferably, the mixed working fluid refrigeration cycle unit further includes a preheater and a compression heat recovery unit, and the expander is connected to the condenser through the preheater, the compressor is connected to the aftercooler through the compression heat recovery unit, and the booster pump is connected to the waste heat exchanger after being connected to the preheater and the compression heat recovery unit in any order.

[0013] Preferably, the organic Rankine cycle coupled mixed refrigerant refrigeration system further includes a generator connected to the expander and an electric motor connected to the compressor, wherein the generator is connected to the compressor.

[0014] Preferably, the mixed refrigerant refrigeration cycle unit further includes a preheater and a compression heat recovery unit, and the mixed refrigerant refrigeration cycle unit further includes an intermediate stage regenerator and a liquid throttling element. The expander is connected to the condenser through the preheater, the compressor is connected to the aftercooler through the compression heat recovery unit, the booster pump is connected to the waste heat exchanger after being connected to the preheater and the compression heat recovery unit in any order, and the booster pump is connected to the liquid throttling element through the intermediate stage regenerator. The outlet of the liquid throttling element is connected to the intermediate stage regenerator, the intermediate stage regenerator is connected to the separator through the regenerating heat exchanger, and the aftercooler is connected to the regenerating heat exchanger through the intermediate stage regenerator.

[0015] The organic Rankine cycle coupled mixed working fluid refrigeration system provided by this invention includes a low-grade heat energy pipeline, an organic Rankine cycle unit, and a mixed working fluid refrigeration cycle unit. The organic Rankine cycle unit is connected to the power system of the mounting platform through the low-grade heat energy pipeline. The low-grade heat energy generated by the power system of the mounting platform drives the organic Rankine cycle unit, and then the organic Rankine cycle unit drives the mixed working fluid refrigeration cycle unit to achieve deep refrigeration. The organic Rankine cycle unit and the mixed working fluid refrigeration cycle unit are coupled and share the same working fluid, eliminating the need for additional power supply for the refrigeration cycle. This improves the overall utilization efficiency of fuel and achieves both power supply and deep refrigeration. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the organic Rankine cycle coupled mixed working fluid refrigeration system provided in Embodiment 1 of the present invention;

[0018] Figure 2 This is a schematic diagram of the organic Rankine cycle coupled mixed working fluid refrigeration system provided in Embodiment 2 of the present invention;

[0019] Figure 3 This is a schematic diagram of the organic Rankine cycle coupled mixed working fluid refrigeration system provided in Embodiment 3 of the present invention;

[0020] Figure 4 This is a schematic diagram of the organic Rankine cycle coupled mixed working fluid refrigeration system provided in Embodiment 4 of the present invention;

[0021] Figure 5 This is a schematic diagram of the organic Rankine cycle coupled mixed working fluid refrigeration system provided in Embodiment 5 of the present invention;

[0022] Figure 6 This is a schematic diagram of the organic Rankine cycle coupled mixed working fluid refrigeration system provided in Embodiment 6 of the present invention.

[0023] Explanation of icon numbers:

[0024] 101. Compressor; 102. Aftercooler; 103. Regenerative heat exchanger; 104. Throttling element; 105. Evaporator; 106. Separator; 107. Intermediate stage regenerator; 108. Liquid throttling element; 109. Gas phase buffer tank; 201. Expander; 202. Condenser; 203. Booster pump; 204. Waste heat exchanger; 205. Preheater; 206. Compression heat recovery unit; 301. Power system of the mounting platform; 302. Low-grade heat energy pipeline; 303. Generator; 304. Electric motor. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0027] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0028] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0029] Example 1

[0030] like Figure 1 As shown, it is an organic Rankine cycle coupled mixed working fluid refrigeration system of Embodiment 1 of the present invention.

[0031] Please see Figure 1An embodiment of the present invention provides an organic Rankine cycle coupled with a mixed working fluid refrigeration system, comprising a low-grade heat energy pipeline 302, an organic Rankine cycle unit, and a mixed working fluid refrigeration cycle unit. The organic Rankine cycle unit is connected to a platform power system 301 via the low-grade heat energy pipeline 302. The waste heat generated by the platform power system 301 drives the organic Rankine cycle unit, which in turn drives the mixed working fluid refrigeration cycle unit to achieve deep refrigeration. The organic Rankine cycle unit and the mixed working fluid refrigeration cycle unit are coupled and share the same working fluid, eliminating the need for additional power supply to the refrigeration cycle. This improves the overall utilization efficiency of fuel and achieves both power supply and deep refrigeration.

[0032] The organic Rankine cycle unit includes a waste heat exchanger 204, an expander 201, a condenser 202, a separator 106, and a booster pump 203 connected in sequence. The organic Rankine cycle unit circulates a mixed working fluid. The waste heat exchanger 204 is connected to a low-grade heat energy pipeline 302. The low-grade heat energy pipeline 302 is externally connected to a platform power system 301, so that the low-grade heat energy generated by the platform power system 301 can be used to heat the mixed working fluid in the waste heat exchanger 204.

[0033] The mixed refrigerant refrigeration cycle unit includes a compressor 101, an aftercooler 102, a regenerating heat exchanger 103, a throttling element 104, an evaporator 105, and a separator 106. The compressor 101, aftercooler 102, regenerating heat exchanger 103, throttling element 104, and evaporator 105 are connected in sequence, and the evaporator 105 is connected to the separator 106 through the regenerating heat exchanger 103. The gas phase outlet of the separator 106 is connected to the compressor 101. A mixed refrigerant circulates in the mixed refrigerant refrigeration cycle unit. The mixed refrigerant expands and does work in the expander 201, generating mechanical energy. The expander 201 drives the compressor 101 to work through mechanical transmission.

[0034] In the organic Rankine cycle coupled mixed working fluid refrigeration system, the mixed working fluid is separated into a gaseous working fluid and a liquid working fluid in the separator 106. The liquid working fluid is pressurized by the booster pump 203 and then heated by the waste heat generated by the platform power system 301 in the waste heat exchanger 204 to become superheated steam. The superheated steam enters the expander 201 and is cooled and depressurized to become low-pressure steam and output mechanical work. The low-pressure steam is cooled by the condenser 202 and then returns to the separator 106 to complete the organic Rankine cycle.

[0035] The gaseous working fluid separated by the separator 106 is pressurized by the compressor 101 and cooled by the aftercooler 102 to form a high-pressure refrigerant. The high-pressure refrigerant is cooled by the low-pressure refrigerant in the regenerating heat exchanger 103 and then throttled by the throttling element 104 to form a low-pressure refrigerant. The low-pressure refrigerant passes through the evaporator 105 and the regenerating heat exchanger 103 in sequence and provides cooling capacity to complete the mixed working fluid refrigeration cycle.

[0036] Understandably, the low-grade heat energy generated by the platform's power system includes, for example, the waste heat from engines in fishing boats, islands, and other areas.

[0037] Optionally, separator 106 is a flash separator with high separation efficiency.

[0038] Optionally, a gas phase buffer tank 109 is chain-connected to the upper part of the separator 106, that is, a gas phase buffer tank 109 is provided between the separator 106 and the compressor 101. By providing a gas phase buffer tank 109, the gas flowing out of the separator 106 can be stabilized, and the working stability of the compressor 101 can be improved.

[0039] Example 2

[0040] Please see Figure 2 The difference between this embodiment and embodiment 1 is that the organic Rankine cycle coupled mixed working fluid refrigeration system in this embodiment also includes a generator 303 connected to the expander 201 and an electric motor 304 connected to the compressor 101. The generator 303 is connected to the compressor 101. The mixed working fluid expands and does work in the expander 201. Then, through the principle of magnetoelectric conversion, the mechanical energy in the expander 201 is converted into electrical energy and stored in the generator 303, thereby realizing the purpose of generating electricity using low-grade thermal energy. The generator 303 further provides electrical energy to the electric motor 304, thereby driving the compressor 101 to work.

[0041] In addition, the motor 304 can be connected to other power sources.

[0042] Other structures and working methods can be referred to in Example 1, and will not be repeated here.

[0043] The organic Rankine cycle coupled mixed working fluid refrigeration system in this embodiment uses an expander 201 and a compressor 101 for electric drive, avoiding complex mechanical transmission devices, making the equipment layout more flexible, and allowing additional electrical energy to be input to ensure normal system operation when the output power of the organic Rankine cycle is insufficient.

[0044] Example 3

[0045] Please see Figure 3The difference between this embodiment and Embodiment 1 is that the organic Rankine cycle unit in this embodiment further includes a preheater 205. The preheater 205 is located between the booster pump 203 and the waste heat exchanger 204, and the expander 201 is connected to the condenser 202 through the preheater 205. After being pressurized by the booster pump 203, the liquid working fluid enters the preheater 205 and is heated by the low-pressure steam discharged from the expander 201. Then, the liquid working fluid enters the waste heat exchanger 204, where it is heated by the waste heat generated by the platform power system 301 and becomes superheated steam. After entering the expander 201, the superheated steam is cooled and depressurized to become low-pressure steam and outputs mechanical work. After being cooled by the condenser 202, the low-pressure steam returns to the separator 106 to complete the organic Rankine cycle.

[0046] Other structures and working methods can be referred to in Example 1, and will not be repeated here.

[0047] The organic Rankine cycle coupled mixed working fluid refrigeration system of this invention improves the efficiency of the organic Rankine cycle by setting a preheater 205 to recover and utilize the residual heat of low-pressure steam.

[0048] Example 4

[0049] Please see Figure 4 The difference between this embodiment and Embodiment 1 is that the mixed working fluid refrigeration cycle unit in this embodiment further includes a compression heat recovery unit 206. The compression heat recovery unit 206 is located between the compressor 101 and the aftercooler 102, and the booster pump 203 is connected to the waste heat exchanger 204 through the compression heat recovery unit 206. After being pressurized by the booster pump 203, the liquid working fluid enters the compression heat recovery unit 206 and is heated by the high-pressure refrigerant discharged from the compressor 101. Then, the liquid working fluid enters the waste heat exchanger 204, where it is heated by the waste heat generated by the platform power system 301 and becomes superheated steam. The superheated steam enters the expander 201, where it is cooled and depressurized to become low-pressure steam and outputs mechanical work. The low-pressure steam is cooled by the condenser 202 and returns to the separator 106 to complete the organic Rankine cycle.

[0050] The gaseous working fluid separated by separator 106 is pressurized by compressor 101 and cooled by liquid working fluid pressurized by booster pump 203 and then cooled by aftercooler 102 to form high-pressure refrigerant. The high-pressure refrigerant is cooled by low-pressure refrigerant in regenerator 103 and then throttled by throttling element 104 to form low-pressure refrigerant. The low-pressure refrigerant passes through evaporator 105 and regenerator 103 in sequence and provides cooling capacity to complete the mixed working fluid refrigeration cycle.

[0051] Other structures and working methods can be referred to in Example 1, and will not be repeated here.

[0052] The organic Rankine cycle coupled mixed working fluid refrigeration system of this invention improves the overall system efficiency by setting up a compression heat recovery device 206 to recover and utilize the compression heat of the high-pressure refrigerant.

[0053] Example 5

[0054] Please see Figure 5 The difference between this embodiment and Embodiment 1 is that the mixed working fluid refrigeration cycle unit in this embodiment further includes an intermediate stage regenerator 107 and a liquid throttling element 108. The intermediate stage regenerator 107 is disposed between the regenerating heat exchanger 103 and the separator 106, and the aftercooler 102 is connected to the regenerating heat exchanger 103 through the intermediate stage regenerator 107. The liquid throttling element 108 is disposed between the booster pump 203 and the intermediate stage regenerator 107. After being pressurized by the booster pump 203, the liquid working fluid is divided into two streams. One stream of liquid working fluid continues to enter the waste heat exchanger 204, and the other stream of liquid working fluid is throttled, cooled, and depressurized by the liquid throttling element 108 and then merges into the low-pressure refrigerant coming out of the regenerating heat exchanger 103. The mixed low-pressure refrigerant enters the intermediate stage regenerator 107 to provide cooling capacity to cool the high-pressure refrigerant coming out of the aftercooler 102, and then returns to the separator 106.

[0055] Other structures and working methods can be referred to in Example 1, and will not be repeated here.

[0056] The organic Rankine cycle coupled mixed working fluid refrigeration system of this invention improves the refrigeration cycle effect of the mixed working fluid by separating a portion of the high-pressure liquid for high-temperature refrigeration after throttling.

[0057] Example 6

[0058] Please see Figure 6 The difference between this embodiment and embodiment 5 is that the booster pump 203 is connected to the liquid throttling element 108 via the intermediate stage regenerator 107, and the outlet of the liquid throttling element 108 is connected to the intermediate stage regenerator 107. The other liquid working fluid, pressurized by the booster pump 203, is first subcooled in the intermediate stage regenerator 107, and then throttled and depressurized by the liquid throttling element 108 before flowing into the low-pressure refrigerant. The mixed low-pressure refrigerant then enters the intermediate stage regenerator 107 to provide cooling for the high-pressure refrigerant, and then returns to the separator 106.

[0059] Other structures and working methods can be referred to in Example 5, and will not be repeated here.

[0060] The organic Rankine cycle coupled mixed working fluid refrigeration system of this invention improves the refrigeration cycle effect of the mixed working fluid by separating a portion of the high-pressure liquid, cooling it through the intermediate stage regenerator 107, and then throttling it through the liquid throttling element 108.

[0061] It is understood that the technical features of the above embodiments can be combined arbitrarily. For example, any two or more of embodiments 2, 3, 4, and 5 can be combined with each other, and any two or more of embodiments 2, 3, 4, and 6 can be combined with each other. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered to be within the scope of this specification.

[0062] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An organic Rankine cycle coupled mixed working fluid refrigeration system, characterized in that, The system includes a low-grade heat energy pipeline, an organic Rankine cycle unit, and a mixed refrigerant refrigeration cycle unit. The organic Rankine cycle unit is connected to the platform's power system via the low-grade heat energy pipeline. The organic Rankine cycle unit includes a waste heat exchanger, an expander, a condenser, a separator, and a booster pump connected sequentially. The waste heat exchanger is connected to the low-grade heat energy pipeline. The mixed refrigerant refrigeration cycle unit includes a compressor, an aftercooler, a regenerative heat exchanger, a throttling element, an evaporator, and the separator. The compressor, aftercooler, regenerative heat exchanger, throttling element, and evaporator are connected sequentially. The evaporator is connected to the separator via the regenerative heat exchanger. The liquid phase outlet of the separator is connected to the booster pump, and the gas phase outlet of the separator is connected to the compressor. Both the organic Rankine cycle unit and the mixed refrigerant refrigeration cycle unit circulate a mixed refrigerant. The mixed refrigerant expands in the expander to drive the compressor.

2. The organic Rankine cycle coupled mixed working fluid refrigeration system as described in claim 1, characterized in that, The expander drives the compressor through mechanical transmission.

3. The organic Rankine cycle coupled mixed working fluid refrigeration system as described in claim 1, characterized in that, A gas phase buffer tank is provided between the separator and the compressor.

4. The organic Rankine cycle coupled mixed working fluid refrigeration system as described in claim 1, characterized in that, The organic Rankine cycle unit also includes a preheater, which is disposed between the booster pump and the waste heat exchanger, and the expander is connected to the condenser through the preheater.

5. The organic Rankine cycle coupled mixed working fluid refrigeration system as described in claim 1, characterized in that, The mixed working fluid refrigeration cycle unit also includes a compression heat recovery unit, which is disposed between the compressor and the aftercooler, and the booster pump is connected to the waste heat exchanger through the compression heat recovery unit.

6. The organic Rankine cycle coupled mixed working fluid refrigeration system as described in claim 1, characterized in that, The mixed working fluid refrigeration cycle unit further includes an intermediate stage regenerator and a liquid throttling element. The intermediate stage regenerator is disposed between the regenerating heat exchanger and the separator, and the aftercooler is connected to the regenerating heat exchanger through the intermediate stage regenerator. The liquid throttling element is disposed between the booster pump and the intermediate stage regenerator.

7. The organic Rankine cycle coupled mixed working fluid refrigeration system as described in claim 1, characterized in that, The mixed working fluid refrigeration cycle unit further includes an intermediate stage regenerator and a liquid throttling element. The intermediate stage regenerator is disposed between the regenerating heat exchanger and the separator, and the aftercooler is connected to the regenerating heat exchanger through the intermediate stage regenerator. The booster pump is connected to the liquid throttling element through the intermediate stage regenerator, and the outlet of the liquid throttling element is connected to the intermediate stage regenerator.

8. The organic Rankine cycle coupled mixed working fluid refrigeration system as described in claim 7, characterized in that, The mixed working fluid refrigeration cycle unit also includes a preheater and a compression heat recovery unit. The expander is connected to the condenser through the preheater, the compressor is connected to the aftercooler through the compression heat recovery unit, and the booster pump is connected to the waste heat exchanger after being connected to the preheater and the compression heat recovery unit in any order.

9. The organic Rankine cycle coupled mixed working fluid refrigeration system as described in claim 1, characterized in that, The organic Rankine cycle coupled mixed refrigerant refrigeration system also includes a generator connected to the expander and an electric motor connected to the compressor, wherein the generator is connected to the compressor.

10. The organic Rankine cycle coupled mixed working fluid refrigeration system as described in claim 9, characterized in that, The mixed refrigerant refrigeration cycle unit further includes a preheater and a compression heat recovery unit. The mixed refrigerant refrigeration cycle unit also includes an intermediate stage regenerator and a liquid throttling element. The expander is connected to the condenser via the preheater. The compressor is connected to the aftercooler via the compression heat recovery unit. The booster pump is connected to the waste heat exchanger after being connected to the preheater and the compression heat recovery unit in any order. The booster pump is connected to the liquid throttling element via the intermediate stage regenerator. The outlet of the liquid throttling element is connected to the intermediate stage regenerator. The intermediate stage regenerator is connected to the separator via the regenerating heat exchanger. The aftercooler is connected to the regenerating heat exchanger via the intermediate stage regenerator.

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