An air refrigeration cycle system coupled with an organic rankine cycle

Abstract

The application belongs to the technical field of refrigeration technology, and relates to an air refrigeration cycle system coupled with an organic Rankine cycle, wherein in the main refrigeration cycle system, an air expander supplies low-temperature and low-pressure air to a cold storage, cold air from the cold storage enters a regenerator in communication, the regenerator is sequentially connected with a first-stage compressor, a second-stage compressor and a waste heat recovery heat exchanger, the waste heat recovery heat exchanger is connected with the regenerator and the air expander, and a cycle is formed; in the organic Rankine cycle system, organic medium steam in the waste heat recovery heat exchanger enters an ORC expander in communication to expand and work, the ORC expander is connected with a condenser, the condenser is connected with a working medium pump and the waste heat recovery heat exchanger, and a cycle is formed. The application can fully utilize renewable energy such as high-temperature exhaust heat of a compressor, solar energy and waste heat, and a compressor is driven by an ORC expander, so that external power consumption of the compressor is reduced, and the performance of the system is improved while the waste heat resource is utilized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of refrigeration and freezing, and particularly relates to an air refrigeration cycle system coupled with an organic Rankine cycle. BACKGROUND

[0002] In the field of food freezing, low temperature below-30 to-70 DEG C is usually required, and air refrigeration technology is one of the main ways to achieve low-temperature refrigeration. At present, the commonly used refrigeration technologies mainly include two-stage cascade refrigeration technology, self-cascade refrigeration technology, air refrigeration technology and mixed working fluid throttling refrigeration technology. Air refrigeration technology has significant advantages in the field of low-temperature freezing and refrigeration due to its simple structure and the absence of frosting.

[0003] However, the conventional air refrigeration technology, such as the conventional simple air refrigeration cycle and the regenerative air refrigeration cycle, has the problem of low refrigeration energy efficiency when producing low temperature, which makes it difficult to compete with the conventional cascade refrigeration system.

[0004] In order to solve this problem, the present application provides an air refrigeration technology coupled with an organic Rankine cycle (ORC) to improve the efficiency of the air refrigeration cycle system. SUMMARY

[0005] The present application aims to solve the above-mentioned problems in the prior art, and provides an air refrigeration cycle system coupled with an organic Rankine cycle. The air refrigeration technology coupled with an organic Rankine cycle provided by the present application can make full use of the high-temperature exhaust heat of the compressor, solar energy and waste heat, and drive the compressor by the ORC expander, thereby reducing the external power consumption of the compressor. At the same time, the use of waste heat resources improves the performance of the system.

[0006] The technical scheme of the present application is as follows:

[0007] An air refrigeration cycle system coupled with an organic Rankine cycle, comprising a main refrigeration cycle system and an organic Rankine cycle system, wherein the main refrigeration cycle system comprises an air expander, a primary compressor, a secondary compressor, a waste heat recovery heat exchanger and a regenerator, the air expander is connected to a cold store and supplies low-temperature and low-pressure air generated by expansion work to the cold store, the cold air from the cold store enters the regenerator in communication, the regenerator is connected to the primary compressor, the secondary compressor and the waste heat recovery heat exchanger in turn, the waste heat recovery heat exchanger is connected to the regenerator, and the regenerator is connected to the air expander to form a main refrigeration cycle.

[0008] The organic Rankine cycle system comprises an ORC expander, a condenser, a working medium pump and a waste heat recovery heat exchanger, organic medium vapor after absorbing heat in the waste heat recovery heat exchanger enters the connected ORC expander to expand and do work, the ORC expander is connected with the condenser, the condenser is connected with the working medium pump, and the working medium pump is connected with the waste heat recovery heat exchanger, forming an organic Rankine cycle.

[0009] Further, the air expander is coaxially connected with the primary compressor and provides power for the primary compressor, and the ORC expander is coaxially connected with the secondary compressor and provides power for the secondary compressor.

[0010] Further, the intermediate heat exchanger is arranged between the primary compressor and the secondary compressor, and the intermediate heat exchanger is connected with the waste heat recovery heat exchanger, the ORC expander, the condenser and the working medium pump in sequence to form a closed circulation loop.

[0011] Further, the intermediate cooler is arranged between the primary compressor and the secondary compressor, and the waste heat recovery heat exchanger is replaced by a generator, the generator is connected with the ORC expander, the condenser and the working medium pump in sequence to form a closed circulation loop.

[0012] Further, the primary compressor is connected with the intermediate cooler, the intermediate cooler is connected with the secondary compressor, and the secondary compressor is directly connected with the regenerator.

[0013] Further, the generator can be heated by a heat source such as solar energy, engine waste heat or industrial waste heat, and organic medium vapor after absorbing heat in the generator enters the connected ORC expander to expand and do work.

[0014] Further, the intermediate cooler is arranged between the primary compressor and the secondary compressor, the generator is arranged between the ORC expander and the waste heat recovery heat exchanger, and the generator is connected with the ORC expander, the condenser, the working medium pump and the waste heat recovery heat exchanger in sequence to form a closed circulation loop.

[0015] Further, the generator can be heated by a heat source such as solar energy, engine waste heat or industrial waste heat, and the medium in the working medium pump enters the waste heat recovery heat exchanger to absorb waste heat, then enters the generator for further heating, and the generated organic medium vapor enters the ORC expander to expand and do work.

[0016] Further, the intermediate heat exchanger is arranged between the primary compressor and the secondary compressor, the generator is arranged between the ORC expander and the waste heat recovery heat exchanger, and the generator is connected with the ORC expander, the condenser, the working medium pump, the intermediate heat exchanger and the waste heat recovery heat exchanger in sequence to form a closed circulation loop.

[0017] The beneficial effects of the present application are as follows:

[0018] The air refrigeration cycle system coupled with the organic Rankine cycle provided by the present application recovers the high-temperature and high-pressure exhaust heat of the compressor (when two-stage compression, the exhaust heat of the first-stage compressor and the high-temperature exhaust heat of the second-stage compressor can be recovered), which is used to drive the organic Rankine power cycle, and the power output of the ORC cycle completely drives the second-stage compressor through coaxial connection, and the first-stage compressor is completely driven by the output power of the expander of the air refrigeration cycle through coaxial connection, so that the air refrigeration is realized without external power consumption, and the energy efficiency of the system is improved.

[0019] While recovering the high-temperature and high-pressure exhaust heat of the compressor, renewable resources or waste heat resources such as solar energy and waste heat resources can be used to add the organic Rankine power cycle to drive the compressor, so as to improve the energy efficiency of the overall air refrigeration cycle, and reduce the high-temperature exhaust pollution of the compressor to the atmosphere, and the system is more energy-saving and environmentally friendly. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The principle diagram of the compressor high-temperature waste heat driving ORC expander provided for the embodiment 1 of the present application is shown in the figure.

[0021] Figure 2 The principle diagram of the first-stage compressor waste heat and the second-stage compressor high-temperature waste heat jointly driving ORC expander provided for the embodiment 2 of the present application is shown in the figure.

[0022] Figure 3 The principle diagram of the solar energy or waste heat driving ORC expander provided for the embodiment 3 of the present application is shown in the figure.

[0023] Figure 4 The principle diagram of the solar energy or waste heat driving ORC expander coupled with the compressor waste heat provided for the embodiment 4 of the present application is shown in the figure.

[0024] Figure 5 The principle diagram of the solar energy or waste heat driving ORC expander coupled with the first-stage and second-stage compressor waste heat provided for the embodiment 5 of the present application is shown in the figure.

[0025] In the above figures, 1 is an air expander, 2 is a cold storage, 3 is a regenerator, 4 is a first-stage compressor, 5 is a second-stage compressor, 6 is an ORC expander, 7 is a waste heat recovery heat exchanger, 8 is a working medium pump, 9 is a condenser, 10 is an intermediate heat exchanger, 11 is a generator, and 12 is an intermediate cooler. DETAILED DESCRIPTION

[0026] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] To further understand the present invention, it will be further described in conjunction with the accompanying drawings and embodiments.

[0028] Example 1

[0029] like Figure 1 As shown, this embodiment provides an air refrigeration cycle system coupled with an organic Rankine cycle. The system includes a main refrigeration cycle system and an organic Rankine cycle system, wherein...

[0030] The main refrigeration cycle system includes an air expander 1, a primary compressor 4, a secondary compressor 5, a waste heat recovery heat exchanger 7, and a regenerator 3. The air expander 1 is connected to the cold storage 2, which is connected to the regenerator 3. The regenerator 3 is sequentially connected to the primary compressor 4, the secondary compressor 5, and the waste heat recovery heat exchanger 7. The waste heat recovery heat exchanger 7 is connected to the regenerator 3, which is connected to the air expander 1. In other words, the cold storage 2 is sequentially connected to the regenerator 3, the primary compressor 4, the secondary compressor 5, the waste heat recovery heat exchanger 7, the regenerator 3, and the air expander 1, forming a closed loop.

[0031] The organic Rankine cycle system includes an ORC expander 6, a condenser 9, a working fluid pump 8, and a waste heat recovery heat exchanger 7. The organic medium vapor that has absorbed heat in the waste heat recovery heat exchanger 7 enters the connected ORC expander 6 to expand and do work. The ORC expander 6 is connected to the condenser 9, the condenser 9 is connected to the working fluid pump 8, and the working fluid pump 8 is connected to the waste heat recovery heat exchanger 7, forming a closed loop.

[0032] Air expander 1 is coaxially connected to primary compressor 4, and ORC expander 6 is coaxially connected to secondary compressor 5.

[0033] The working process of the air refrigeration cycle system coupled with the organic Rankine cycle described above is as follows:

[0034] The main refrigeration cycle system works as follows: the cold air coming out of the cold storage 2 enters the regenerator 3 for heat exchange and temperature rise, and then enters the first-stage compressor 4 for first-stage compression. The compressed air enters the second-stage compressor 5 for compression. The discharged high-temperature and high-pressure air releases heat in the waste heat recovery heat exchanger 7 and then enters the regenerator 3 for further cooling. Subsequently, it enters the air expander 1 to expand and do work, generating low-temperature and low-pressure air to supply the cold storage 2, thus completing the refrigeration cycle.

[0035] In the above cycle, the air expander 1 and the primary compressor 4 are coaxially connected, and the primary compressor 4 is powered by the air expander 1;

[0036] The organic Rankine cycle system for recovering the exhaust heat of the compressor comprises a working medium pump 8, a waste heat recovery heat exchanger 7, an ORC expander 6 and a condenser 9, and the working process is as follows: the organic medium vapor after absorbing heat from the waste heat recovery heat exchanger 7 enters the ORC expander 6 to expand and do work, the low-temperature and low-pressure gas after expansion enters the condenser 9 to be cooled and then enters the working medium pump 8 to increase the pressure, thus completing the organic Rankine power cycle;

[0037] In the above cycle, the ORC expander 6 is coaxially connected with the secondary compressor 5, and the output power of the ORC expander 6 is used to drive the secondary compressor 5.

[0038] Embodiment 2

[0039] As shown in Figure 2 , an intermediate heat exchanger 10 is arranged between the primary compressor 4 and the secondary compressor 5, and the intermediate heat exchanger 10 is sequentially connected with the waste heat recovery heat exchanger 7, the ORC expander 6, the condenser 9 and the working medium pump 8 to form a closed circulation loop.

[0040] This embodiment is based on Embodiment 1, and the exhaust waste heat of the primary compressor 4 is recovered at the same time. An intermediate heat exchanger 10 is arranged between the primary compressor 4 and the secondary compressor 5 to absorb the exhaust waste heat of the primary compressor 4 for preheating of the organic Rankine cycle.

[0041] Embodiment 3

[0042] As shown in Figure 3 , this embodiment is based on Embodiment 1, and the waste heat recovery heat exchanger 7 is replaced by a generator 11, the generator 11 is sequentially connected with the ORC expander 6, the condenser 9 and the working medium pump 8 to form a closed circulation loop; and an intermediate cooler 12 is arranged between the primary compressor 4 and the secondary compressor 5, the exhaust of the primary compressor 4 directly passes through the intermediate cooler 12 to be cooled, and the heat is discharged to the atmosphere, and the secondary compressor 5 is directly connected with the regenerator 3.

[0043] The working process of the above air refrigeration cycle system coupled with the organic Rankine cycle is as follows:

[0044] The working process of the main refrigeration cycle system is as follows: the cold air from the cold storage 2 enters the regenerator 3 to be heat-exchanged and warmed up, then enters the primary compressor 4 to be compressed, the compressed air enters the intermediate cooler 12 to be cooled, then enters the secondary compressor 5 to be compressed, the high-temperature and high-pressure air discharged from the secondary compressor 5 enters the regenerator 3 to be cooled, then enters the air expander 1 to be expanded and do work, and low-temperature and low-pressure air is supplied to the cold storage 2 to complete the refrigeration cycle;

[0045] Similarly, in the above cycle, the air expander 1 and the primary compressor 4 are coaxially connected, and the air expander 1 provides power for the primary compressor 4;

[0046] The working process of the solar or waste heat driven organic Rankine cycle system: the cycle is composed of a working fluid pump 8, a generator 11, an ORC expander 6, and a condenser 9 connected in sequence; the solar or waste heat is used to heat the generator 11, and the organic medium vapor generated by absorbing heat from the generator 11 enters the ORC expander 6 to expand and do work, and the low-temperature and low-pressure gas after expansion enters the condenser 9 to cool and then enters the working fluid pump 8 to increase the pressure, completing the organic Rankine power cycle;

[0047] Similarly, in the above cycle, the ORC expander 6 and the secondary compressor 5 are coaxially connected, and the output power of the ORC expander 6 is used to drive the secondary compressor 5.

[0048] Example 4

[0049] As shown in Figure 4 , this embodiment is provided with an intermediate cooler 12 between the primary compressor 4 and the secondary compressor 5, and a generator 11 between the ORC expander 6 and the waste heat recovery heat exchanger 7, and the generator 11 is connected with the ORC expander 6, the condenser 9, the working fluid pump 8, and the waste heat recovery heat exchanger 7 in sequence, forming a closed circulation loop.

[0050] The generator 11 in the system of this embodiment is also heated by solar energy or waste heat, and the medium in the working fluid pump 8 enters the waste heat recovery heat exchanger 7 to absorb waste heat and then enters the generator 11 for further heating, and the generated organic medium vapor enters the ORC expander 6 to expand and do work.

[0051] The working process of the above air refrigeration cycle system coupled with the organic Rankine cycle is as follows:

[0052] The working process of the main refrigeration cycle system: the cold air from the cold storage 2 enters the regenerator 3 to exchange heat and increase temperature, enters the primary compressor 4 for the first stage compression, the compressed air enters the intermediate cooler 12 to cool and then enters the secondary compressor 5 for compression, the high-temperature and high-pressure air discharged enters the waste heat recovery heat exchanger 7 to cool and release heat, then enters the regenerator 3 for further cooling and temperature reduction, then enters the air expander 1 to expand and do work and produce low-temperature and low-pressure air to supply the cold storage 2, completing the refrigeration cycle;

[0053] In the above cycle, the air expander 1 and the primary compressor 4 are coaxially connected, and the air expander 1 provides power for the primary compressor 4;

[0054] The working process of the organic Rankine cycle system driven by the solar energy or waste heat coupled compressor exhaust waste heat is as follows: the cycle is composed of a working medium pump 8, a waste heat recovery heat exchanger 7, a generator 11, an ORC expander 6 and a condenser 9 connected in sequence;

[0055] The medium out of the working medium pump 8 first absorbs the high-temperature and high-pressure exhaust waste heat of the secondary compressor 5 in the waste heat recovery heat exchanger 7, then enters the generator 11 for further heating, the organic medium vapor generated by the heating enters the ORC expander 6 for expansion work, the low-temperature and low-pressure gas after the expansion enters the condenser 9 for cooling and then enters the working medium pump 8 to increase the pressure, and the organic Rankine power cycle is completed.

[0056] In the above cycle, the output power of the ORC expander 6 is used to drive the secondary compressor 5, and the two are coaxially connected.

[0057] Embodiment 5

[0058] As shown in Figure 5 Compared with the system of embodiment 1, the system of the present embodiment is provided with an intermediate heat exchanger 10 between the primary compressor 4 and the secondary compressor 5, and a generator 11 between the ORC expander 6 and the waste heat recovery heat exchanger 7, and the generator 11 is connected with the ORC expander 6, the condenser 9, the working medium pump 8, the intermediate heat exchanger 10 and the waste heat recovery heat exchanger 7 in sequence to form a closed cycle loop.

[0059] The present embodiment is based on embodiment 4, and the intermediate heat exchanger 10 is used to replace the intermediate cooler 12. The utilization of the exhaust heat of the primary compressor 4 is increased, and the compressor exhaust heat is delivered to the organic Rankine cycle.

[0060] The working process of the organic Rankine cycle system is as follows:

[0061] The working medium out of the working medium pump 8 first absorbs the exhaust waste heat of the primary compressor 4 in the intermediate heat exchanger 10, then absorbs the high-temperature and high-pressure exhaust waste heat of the secondary compressor 5 in the waste heat recovery heat exchanger 7, then enters the generator 11 for further heating, the organic working medium vapor generated by the heating enters the ORC expander 6 for expansion work, the low-temperature and low-pressure gas after the expansion enters the condenser 9 for cooling and then enters the working medium pump 8 to increase the pressure, and the organic Rankine power cycle is completed.

[0062] In the above cycle, the output power of the ORC expander 6 is used to drive the secondary compressor 5, and the two are coaxially connected.

[0063] The above description is only the preferred embodiments of the present application, and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent features. Any modification, equivalent replacement, modification, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An air refrigeration cycle system coupled with an organic Rankine cycle, characterized by, The application relates to a refrigeration system, which comprises a main refrigeration cycle system and an organic Rankine cycle system. The air expander is coaxially connected with the primary compressor and provides power for the primary compressor. The primary compressor and the secondary compressor are provided with an intermediate heat exchanger, which is sequentially connected with the waste heat recovery heat exchanger, the ORC expander, the condenser and the working medium pump to form a closed circulation loop.

2. The air cycle refrigeration system coupled with an organic Rankine cycle of claim 1, wherein, The primary compressor and the secondary compressor are provided with an intermediate heat exchanger, which is sequentially connected with the waste heat recovery heat exchanger, the ORC expander, the condenser and the working medium pump to form a closed circulation loop.

3. The air cycle refrigeration system coupled with an organic Rankine cycle of claim 1, wherein, The generator can utilize solar energy, engine waste heat or industrial waste heat as heat source.

4. The air cycle refrigeration system coupled with an organic Rankine cycle of claim 3, wherein, The primary compressor and the secondary compressor are provided with an intermediate heat exchanger, which is sequentially connected with the waste heat recovery heat exchanger, the ORC expander, the condenser and the working medium pump to form a closed circulation loop.

5. The air cycle refrigeration system coupled with an organic Rankine cycle of claim 1, wherein, ​

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