Air compressor unit and adiabatic compressed air energy storage system

Abstract

The present application relates to compressed air energy storage technology field, provide a kind of air compressor unit and adiabatic compressed air energy storage system.The air compressor unit described above, including: multistage series air compressor, the variable compression efficiency of each stage air compressor increases successively, and the process parameter configuration of each stage air compressor meets the following conditions: the air compressor unit and adiabatic compressed air energy storage system provided by the present application, by reasonably configuring the exhaust temperature parameter configuration between each stage air compressor, the best combination of compressed exhaust temperature and compression power can be realized, so as to realize the improvement of system overall energy efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressed air energy storage, and in particular to an air compressor unit and an adiabatic compressed air energy storage system. BACKGROUND

[0002] As a large-scale long-time energy storage technology, advanced adiabatic compressed air energy storage has realized engineering demonstration of different capacity levels in China. In the process of energy absorption, the adiabatic compressed air energy storage system uses renewable energy waste, thermal power waste or off-peak power to drive the air compressor to compress the ambient air, obtain high-temperature and high-pressure compressed air, and then use the heat transfer medium to absorb heat and store it after heat exchange. The air is cooled and enters the gas storage device, so as to store the electric energy in the form of heat transfer medium and compressed air. In the process of energy release, the stored compressed air exchanges heat with the stored heat transfer medium, absorbs heat and enters the air expander to reduce pressure and do work, and drives the generator to rotate and generate electricity, while the cooled heat transfer medium is stored, so as to realize the regeneration of electric energy.

[0003] According to the working principle of the compressed air energy storage power generation system, the compression process has a double influence on the overall energy storage characteristics of the system. First, the exhaust temperature of the compression process determines the heat storage temperature, which further determines the inlet temperature of the expansion process. According to classical thermodynamics, the inlet temperature is positively correlated with the output of the expansion process. Therefore, the increase of the exhaust temperature of the compressor will increase the output power of the expansion process, which will help to improve the overall energy efficiency of the system under the condition of constant compression power. However, according to classical thermodynamics, the increase of the exhaust temperature of the compression process will also increase the power consumption of the compression process, which will have an opposite effect on the overall energy efficiency of the system.

[0004] From the above, it can be seen that the exhaust temperature of the compression process and the power consumption of the compression process have positive and negative effects on the energy efficiency of the adiabatic compressed air energy storage system. It is necessary to optimize the combination of the exhaust temperature and the power consumption of each stage of the compressor to determine the optimal exhaust temperature and the power consumption of each stage of the compressor, so as to make the overall energy efficiency of the system reach the highest level. At present, there is no special process design and optimization method for the advanced adiabatic compressed air energy storage air compressor unit. SUMMARY

[0005] The present application provides an air compressor unit and an adiabatic compressed air energy storage system to solve the problem of low energy efficiency of the adiabatic compressed air energy storage system in the prior art and improve the energy efficiency of the adiabatic compressed air energy storage system.

[0006] In one aspect, the present application provides an air compressor unit, comprising: a plurality of air compressors connected in series, the multi-variable compression efficiency of each air compressor increasing in turn, and the process parameters of each air compressor being configured to satisfy the following conditions:

[0007]

[0008]

[0009] wherein m ci and m ci+1 are the mass flow of through-flow air of the i-th and (i+1)-th stage of the air compressor, respectively, and are the polytropic compression efficiency of the i-th and (i+1)-th stage of the air compressor, respectively, is the compression discharge temperature of the i-th stage of the air compressor, C ci and C ci+1 are polynomials of the i-th and (i+1)-th stage of the air compressor with respect to the above parameters.

[0010] According to the present application, the air compressor is provided with an inlet guide vane valve at the inlet side.

[0011] According to the present application, the air compressor is provided with an outlet throttle valve at the outlet side.

[0012] According to the present application, the air compressor further comprises a flow detection device adapted to monitor the flow of the air compressor.

[0013] According to the present application, the air compressor further comprises a temperature detection device adapted to monitor the compression discharge temperature of each stage of the air compressor.

[0014] In another aspect, the present application provides an adiabatic compressed air energy storage system, comprising: the air compressor group according to any one of the above, a heat storage module, an expander group and a gas storage device;

[0015] The air compressor group is connected to the gas storage device, the gas storage device is connected to the expander group, and the heat storage module is connected to both the air compressor group and the expander group.

[0016] According to the present application, the air compressor group comprises a plurality of constant-pressure air compressors connected in series, and the gas storage device is a constant-pressure gas storage device.

[0017] According to the present application, the constant-pressure gas storage device is a constant-pressure gas storage bag.

[0018] According to the present application, the adiabatic compressed air energy storage system further comprises a first heat exchanger, the constant-pressure air compressor is connected to the first heat exchanger, and the first heat exchanger is connected to the heat storage module.

[0019] The adiabatic compressed air energy storage system provided by the application further comprises a second heat exchanger, the heat storage module is connected with the second heat exchanger, and the second heat exchanger is connected with the expander set.

[0020] The air compressor set and the adiabatic compressed air energy storage system provided by the application can realize the optimal combination of compressed exhaust temperature and compressed power by reasonably configuring the exhaust temperature parameters of the air compressors at different levels, so that the overall energy efficiency of the system is improved.

[0021] Other advantages, objects, and features of the application will be set forth in part in the following specification taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art from a consideration of the following specification and drawings, or can be learned from the practice of the application. The advantages and other objects of the application can be realized and attained by means of the instrumentalities and combinations pointed out in the following specification. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0023] Figure 1 is a schematic diagram of one of the air compressor sets provided by the application;

[0024] Figure 2 is a schematic diagram of another air compressor set provided by the application;

[0025] Figure 3 is a schematic diagram of the adiabatic compressed air energy storage system provided by the embodiment of the application;

[0026] Figure 4 is a schematic diagram of the gas storage device in the adiabatic compressed air energy storage system provided by the embodiment of the application.

[0027] Reference signs:

[0028] 1, heat storage module; 2, gas storage device; 3, constant-pressure air compressor; 4, first heat exchanger; 5, second heat exchanger; 6, expander. DETAILED DESCRIPTION

[0029] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0030] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0031] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of different embodiments or examples without contradiction.

[0032] In view of the defects of the existing adiabatic compressed air energy storage system, the present application provides an air compressor unit and an adiabatic compressed air energy storage system.

[0033] The air compressor unit and the adiabatic compressed air energy storage system provided by the present application will be described below. Figures 1 to 4 The air compressor unit and the adiabatic compressed air energy storage system provided by the present application will be described below.

[0034] It should be noted that the air compressor unit provided by the present application has two application scenarios, one of which is applied to design scheme optimization in the system design stage, and the other of which is applied to operation scheme optimization in the actual operation stage. The embodiments of the air compressor unit provided by the present application applied to design scheme optimization in the system design stage and operation scheme optimization in the actual operation stage will be described in detail below.

[0035] Design scheme optimization applied to system design stage

[0036] As Figure 1The figure shows a schematic diagram of one of the air compressor units provided by the present application. In this embodiment, the constant pressure air compressor unit includes multiple air compressors A1 to An connected in series, the polytropic compression efficiency of each air compressor increases in turn, heat exchangers B1 to Bn are arranged between adjacent air compressors, each heat exchanger uses low-temperature heat-carrying medium to exchange heat with the air compressor exhaust, and the air compressor exhaust temperature is reduced to the ambient temperature level before it enters the next stage air compressor. At the same time, gas-liquid separators S1 to Sn are arranged between adjacent air compressors, which are used to separate the liquid water condensed after cooling the compressed air to avoid liquid water entering the subsequent process flow. Therefore, the air mass flow entering the next stage air compressor will be less than the previous stage air compressor, and the process parameter configuration of each air compressor meets the following conditions:

[0037]

[0038]

[0039] wherein m ci and m ci+1 are the through-flow air mass flow of the i-th and i+1-th air compressors, and are the polytropic compression efficiency of the i-th and i+1-th air compressors, is the compression exhaust temperature of the i-th air compressor, C ci and C ci+1 are the polynomials of the i-th and i+1-th air compressors with respect to the above parameters.

[0040] The above formula shows that when the ratio of the polynomials of the adjacent two-stage air compressors is equal to , the overall energy efficiency of the adiabatic compressed air energy storage system reaches the optimal level. Since the parameters m ci , and change dynamically during the actual operation of the system, the present application optimizes the parameter ratio between the air compressors in each stage by the above method, so that the overall energy efficiency of the adiabatic compressed air energy storage system reaches the optimal level under the condition of dynamic operation of the system.

[0041] Due to gas-liquid separation, the through-flow air mass flow of each air compressor is not equal, and at this time, attention should be paid to the product of the through-flow air mass flow and the compression exhaust temperature of each air compressor, and the ratio of the polytropic compression efficiency of each air compressor.

[0042] For example, Figure 2Fig. 2 is a schematic diagram of the second embodiment of the air compressor unit provided by the present application. In this embodiment, the constant pressure air compressor unit comprises a plurality of air compressors A1 to An connected in series, the polytropic compression efficiency of each air compressor decreases in turn, and heat exchangers B1 to Bn are arranged between adjacent air compressors. Each heat exchanger exchanges heat between the low-temperature heat-carrying medium and the air compressor exhaust gas, and reduces the temperature of the exhaust gas to the ambient temperature level before it enters the next stage air compressor. In the case where the air does not contain moisture or has low humidity, no gas-liquid separator is arranged. At this time, the air mass flow of each air compressor is equal, and the process parameter configuration of each air compressor satisfies the following conditions:

[0043]

[0044]

[0045] Similarly, and are the polytropic compression efficiencies of the i-th and i+1-th air compressors, respectively, is the compression exhaust temperature of the i-th air compressor, C ci and C ci+1 are the polynomials of the i-th and i+1-th air compressors with respect to the above parameters.

[0046] That is, in the ideal state, due to gas-liquid separation, the mass flow of the air passing through each air compressor is equal. At this time, only the ratio of the compression exhaust temperature of each air compressor to the polytropic compression efficiency of each air compressor needs to be concerned.

[0047] Operation scheme optimization in the actual operation stage

[0048] Even if the multi-stage air compressor unit has met the above optimization configuration conditions under the design conditions, due to the interference factors such as the actual operation environment, pipeline resistance, etc., the actual operation parameters of each air compressor may deviate from the established configuration. By measuring the mass flow of the air passing through each air compressor, the compression exhaust temperature and the polytropic compression efficiency, it can be quickly and conveniently judged whether the actual operation parameters of each air compressor deviate from the established configuration according to the above optimization configuration conditions.

[0049] In some embodiments, if there is a case of actual operation deviating from the optimal configuration condition, the outlet throttle valve of the air compressor and / or the inlet guide vane valve of the air compressor can be set to adjust the exhaust pressure of each air compressor under the condition of meeting the safety operation constraint of the air compressor module. At the same time, the flow detection device, temperature detection device, etc. can be used to monitor the flow, exhaust temperature and polytropic compression efficiency of each air compressor in real time, and calculate whether the above optimization configuration conditions are met or as close as possible.

[0050] The air compressor unit provided by this invention can achieve the optimal combination of exhaust temperature of each stage of the compressor and total compression power by reasonably configuring the exhaust temperature parameters between each stage of the air compressor, thereby improving the overall energy efficiency of the system.

[0051] like Figure 3 As shown, another aspect of the present invention provides an adiabatic compressed air energy storage system, comprising: an air compressor unit, a heat storage module 1, an expander unit, and a gas storage device 2 as described in the above embodiment; the air compressor unit is connected to the gas storage device 2, the gas storage device 2 is connected to the expander unit, and the heat storage module 1 is connected to both the air compressor unit and the expander unit.

[0052] The air compressor unit includes a multi-stage series constant pressure air compressor 3, and the air storage device 2 is a constant pressure air storage device 2.

[0053] like Figure 3 As shown, in this embodiment, the constant pressure air compressor 3 is exemplified by a two-stage design. Figure 4 As shown, the constant pressure air storage device 2 is a constant pressure air storage bladder. In use, the constant pressure air storage bladder can be fixed in deep water. When the constant pressure air storage bladder is inflated or deflated, the external water pressure is always consistent with the internal air pressure of the constant pressure air storage bladder. Under the premise of constant water pressure, the air storage pressure inside the constant pressure air storage bladder can also be kept constant at all times.

[0054] Specifically, in this embodiment, a first heat exchanger 4 and a second heat exchanger 5 are also included. Each stage of the constant-pressure air compressor 3 is connected to the first heat exchanger 4. The first heat exchanger 4 is connected to the heat storage module 1. The heat storage module 1 is connected to the second heat exchanger 5. The second heat exchanger 5 is connected to the expander unit. Each stage of the constant-pressure air compressor 3 is connected to the heat storage module 1 via the first heat exchanger 4.

[0055] Since all air compressors are constant pressure air compressors, there is no need to install a cooling device in the system to cool the air discharged from non-constant pressure air compressors, thus reducing the system's heat loss.

[0056] In this embodiment, the expander unit includes two-stage expanders 6. Both expanders 6 are connected to the heat storage module 1 via a second heat exchanger 5, and can use the heat stored in the heat storage medium in the heat storage module 11 to heat the air, and then pass the heated air into the expander 6 to expand and do work.

[0057] The adiabatic compressed air energy storage system provided by the application can be applied to a constant pressure system (only a constant pressure air compressor 3 is provided in the system), at this time, the gas storage device 2 stores gas in a constant pressure mode, the internal pressure of the gas storage device 2 remains constant when discharging, and the inlet pressure of the expander set is also constant. At this time, all the air compressors work in a stable working condition, and the discharge pressure and temperature are stable, so that the compressed heat energy in the exhaust gas can be stored into the heat storage module 1 efficiently. Since the gas storage device 2 is constant pressure, the stored air can be completely discharged for the expander.

[0058] The working principle of the adiabatic compressed air energy storage system provided by the application is as follows:

[0059] When the system charges and stores energy, the air compressor set is continuously compressed by renewable energy, abandoned electricity, thermal power generation surplus electricity or valley electricity, the exhaust gas of the constant pressure air compressor 3 is first cooled by heat exchange with the heat carrying medium through the first heat exchanger 4, and then enters the gas storage device 2 through the pipeline for storage.

[0060] When the system discharges and generates electricity, the compressed air enters the second heat exchanger 5 and exchanges heat with the heat storage medium flowing out of the heat storage module 1, so that the temperature of the compressed air is increased, and the heat absorption and temperature rise of the compressed air enter the expander 6 to expand and do work.

[0061] In specific implementation, a throttle valve can be arranged on the outlet pipeline of the gas storage device 2 to stabilize the discharge air pressure at a certain set value, and then the air enters the expander set.

[0062] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, but not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. An air compressor unit, characterized in that, include: In a multi-stage air compressor connected in series, the polytropic compression efficiency of each stage of the air compressor increases sequentially, and the process parameters of each stage of the air compressor are configured to meet the following conditions: ； ； in, and The first Level and First +1 level air compressor flow rate and No. Level and First The variable compression efficiency of the air compressor described in +1 level For the first The compressed exhaust temperature of the air compressor described above. The first Level and First +1 level is the polynomial of the air compressor with respect to the above parameters.

2. The air compressor unit according to claim 1, characterized in that, The air compressor is equipped with an inlet guide vane valve on the inlet side.

3. The air compressor unit according to claim 1, characterized in that, The air compressor is equipped with an outlet throttle valve on its outlet side.

4. The air compressor unit according to claim 1, characterized in that, It also includes a flow detection device suitable for monitoring the flow rate of the air compressor.

5. The air compressor unit according to claim 1, characterized in that, It also includes a temperature detection device suitable for monitoring the compressed exhaust temperature of the air compressors at all levels.

6. An adiabatic compressed air energy storage system, characterized in that, include: The air compressor unit, heat storage module, expander unit, and gas storage device as described in any one of claims 1 to 5; The air compressor unit is connected to the air storage device, the air storage device is connected to the expander unit, and the heat storage module is connected to both the air compressor unit and the expander unit.

7. The adiabatic compressed air energy storage system according to claim 6, characterized in that, The air compressor unit includes a multi-stage constant pressure air compressor connected in series, and the air storage device is a constant pressure air storage device.

8. The adiabatic compressed air energy storage system according to claim 7, characterized in that, The constant pressure gas storage device is a constant pressure gas storage bag.

9. The adiabatic compressed air energy storage system according to any one of claims 7 to 8, characterized in that, It also includes a first heat exchanger, the constant pressure air compressor is connected to the first heat exchanger, and the first heat exchanger is connected to the heat storage module.

10. The adiabatic compressed air energy storage system according to any one of claims 6 to 8, characterized in that, It also includes a second heat exchanger, the heat storage module is connected to the second heat exchanger, and the second heat exchanger is connected to the expander unit.

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