Optimization device for gradient utilization of energy of compressed air energy storage system

Abstract

The utility model relates to the technical field of energy storage, in particular to an energy gradient utilization optimizing device of a compressed air energy storage system, which comprises a compression system, an expansion system and a waste heat recovery system, the compression system is used for compressing air to obtain high-pressure air, and the high-pressure air is stored in an air storage; when high-pressure air in the gas storage flows into the expansion system, the expansion system heats the high-pressure air through the first heat conduction oil so as to drive the expansion unit to do work to generate electricity. The waste heat recovery system is used for enabling cold water to absorb heat energy generated in the compression process and then flow into the hot water tank when the compression system compresses the air to be in the preset high-temperature and high-pressure state, and enabling hot water in the hot water tank and second heat conduction oil generated by heating the high-pressure air to flow into the evaporator. And steam generated by the evaporator is used for driving the turbo expander to do work and generate power. Therefore, the problems that in the background technology, the energy utilization efficiency is not high, and waste heat is not fully utilized are solved, the overall conversion efficiency of the system is improved, and energy loss is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of energy storage, particularly relates to a compressed air energy storage system energy cascade utilization optimization device. BACKGROUND

[0002] The compressed air energy storage system is a kind of compressed air to high temperature and high pressure state by consuming the power stored in the grid during low valley period or renewable energy generation abandoned wind power, abandoned light and electricity, and when high load is needed, high-pressure air is released from gas storage chamber to push expander to work to generate electricity to obtain stable power.The compressed air energy storage can realize large energy storage capacity, high efficiency and long time storage.

[0003] At present, according to the heat source required by the high-pressure air temperature rise at the outlet of the gas storage chamber in the expansion stage, it is roughly divided into two categories, namely the conventional compressed air energy storage system of burning fossil energy and the advanced heat-insulated compressed air energy storage system of heat storage, the conventional compressed air energy storage needs to burn fossil energy and high-pressure air to improve the inlet gas temperature, so as to drive the expander to work and generate electricity.The advanced heat-insulated compressed air energy storage system of heat storage stores the compression heat generated in the compression process in the heat storage system, and heats the high-pressure air at the outlet of the gas storage chamber in the energy release process, to drive the expander to work.Although the advanced heat-insulated compressed air energy storage system of heat storage has achieved good results, many demonstration projects have been built in China, but the temperature of the heat stored by the heat storage device in the compression stage cannot greatly meet the high-pressure air temperature at the inlet of the expander, which further leads to the need to further improve the overall conversion efficiency of the system.Furthermore, the temperature of the heat exchange medium flowing out of the heat exchanger in the expansion process and the exhaust gas of the end expander are still in a certain medium temperature state, and if this part of heat directly flows into the cold tank, it will increase the energy loss and heat loss.In view of the above analysis, how to further improve the inlet air temperature of the expander and the further utilization of the heat exchange medium heat in the expansion stage and ensure its efficient operation is a problem to be solved. UTILITY MODEL CONTENTS

[0004] The utility model provides a kind of compressed air energy storage system energy cascade utilization optimization device to solve the problem that energy utilization efficiency is not high and waste heat is not fully utilized mentioned in background art, improves the overall conversion efficiency of system, reduces energy loss.

[0005] The utility model provides a kind of compressed air energy storage system energy cascade utilization optimization device in the first aspect embodiment of the utility model, the device includes compression system, expansion system and waste heat recovery system, wherein,

[0006] The compression system is connected with the waste heat recovery system, and the compression system is used to compress air to a preset high temperature and high pressure state to obtain high-pressure air, and store the high-pressure air into gas storage library;

[0007] The expansion system is connected with the air reservoir, and the expansion system heats the high-pressure air by using the first heat-conducting oil when the high-pressure air in the air reservoir flows into the expansion system, so as to drive the expansion unit to generate power.

[0008] The waste heat recovery system is connected with the expansion system, and the waste heat recovery system is used for absorbing heat generated in the compression process by using cold water when the compression system compresses air to a preset high-temperature and high-pressure state, and then the cold water flows into a hot water tank, and the hot water in the hot water tank and the second heat-conducting oil generated by heating the high-pressure air flow into an evaporator, so as to drive the turbine expansion machine to generate power by using steam generated by the evaporator, wherein the temperature of the second heat-conducting oil is lower than the temperature of the first heat-conducting oil.

[0009] According to an embodiment of the utility model, the compression system comprises:

[0010] The motor unit is connected with the compressor unit.

[0011] The compressor unit comprises at least one compressor, and air is compressed to a preset high-temperature and high-pressure state by the at least one compressor.

[0012] The air reservoir is connected with the compressor unit, and the air reservoir is used for storing the high-pressure air.

[0013] According to an embodiment of the utility model, the expansion system comprises:

[0014] The cold oil tank is used for storing third heat-conducting oil, wherein the temperature of the third heat-conducting oil is lower than the temperature of the second heat-conducting oil.

[0015] The solar heat collector is connected with the output end of the cold oil tank, and the solar heat collector is used for heating the third heat-conducting oil flowing out of the cold oil tank to obtain the first heat-conducting oil.

[0016] The hot oil tank is connected with the output end of the solar heat collector, and the hot oil tank is used for storing the first heat-conducting oil.

[0017] The intermediate heater group is connected with the output end of the hot oil tank, and the intermediate heater group is used for heating the high-pressure air by using the first heat-conducting oil flowing out of the hot oil tank, so as to drive the expansion unit to generate power.

[0018] According to an embodiment of the utility model, the expansion system further comprises:

[0019] An expander set is connected with the intermediate heater set, and the expander set comprises at least one stage of expander.

[0020] A throttle valve is connected with the output end of the gas storage, and the output end of the throttle valve is connected with the expander of the first stage of the expander set.

[0021] According to an embodiment of the present application, the number of intermediate heaters of the intermediate heater set is the same as the number of expanders of the expander set.

[0022] According to an embodiment of the present application, the intermediate heaters of the intermediate heater set are arranged at intervals with the expanders of the expander set.

[0023] According to an embodiment of the present application, the waste heat recovery system comprises:

[0024] A turbo expander;

[0025] An evaporator is connected with the hot water tank at a first input end, connected with the output end of the intermediate heater set at a second input end, and connected with the input end of the turbo expander at an output end, and is used for converting the hot water and the second heat conducting oil into steam to drive the turbo expander to work and generate electricity.

[0026] A condenser is connected with the output end of the turbo expander at an input end, and is used for condensing the exhaust steam of the turbo expander into saturated liquid.

[0027] A working medium pump is connected with the output end of the condenser at an input end, and connected with the third input end of the evaporator at an output end, and is used for re-pressurizing the condensed saturated liquid and transmitting the condensed saturated liquid to the evaporator.

[0028] According to an embodiment of the present application, the waste heat recovery system further comprises:

[0029] A stage-to-stage cooler set, and the number of stage-to-stage coolers of the stage-to-stage cooler set is the same as the number of compressors of the compressor set.

[0030] According to an embodiment of the present application, the stage-to-stage coolers of the stage-to-stage cooler set are arranged at intervals with the compressors of the compressor set.

[0031] The compressed air energy storage system energy cascade utilization optimization device provided by the embodiment of the utility model can compress air to obtain high-pressure air, the expansion system uses the first heat conducting oil to heat the high-pressure air, drives the expander set to work and generates electricity, the waste heat recovery system makes the hot water in the hot water tank and the second heat conducting oil generated by heating the high-pressure air flow into the evaporator, so as to drive the turbine expander to work and generate electricity by using the steam generated by the evaporator.

[0032] The additional aspects and advantages of the utility model will be partially given in the following description, some will become obvious from the following description, or be known by the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0033] The above and / or additional aspects and advantages of the utility model will become apparent and more readily appreciated from the following description of the embodiments, with reference to the following drawings, wherein:

[0034] Figure 1 It is a structure schematic drawing of compressed air energy storage system energy cascade utilization optimization device provided by the embodiment of the utility model.

[0035] The compressed air energy storage system energy cascade utilization optimization device, 100- the compression system, 200- the expansion system, 300- the waste heat recovery system, 101- the motor set, 102- the compressor set, 103- the gas storage, 201- the cold oil tank, 202- the solar heat collector, 203- the hot oil tank, 204- the intermediate heater group, 205- the expander set, 206- the throttle valve, 207- the reheater, 301- the turbine expander, 302- the evaporator, 303- the condenser, 304- the working medium pump, 305- the interstage cooler group, 306- the cold water tank, 307- the hot water tank, 308- the heat exchanger, H1- the first interstage cooler, H2- the second interstage cooler, H3- the third interstage cooler, H4- the first intermediate heater, H5- the second intermediate heater, CP1- the first compressor, CP2- the second compressor, CP3- the third compressor, TB1- the first expander, TB2- the second expander, W1- the condensing medium, W2- the condensing medium, W3- the heat exchange medium, W4- the heat exchange medium. DETAILED DESCRIPTION

[0036] The embodiments of the utility model will be described in detail below, the examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the utility model, and cannot be understood as limiting the utility model.

[0037] The compression air energy storage system energy cascade utilization optimization device provided by the embodiment of the present application is described below with reference to the accompanying drawings. In view of the problems of low energy utilization efficiency and insufficient utilization of waste heat mentioned in the background art, the present application provides a compression air energy storage system energy cascade utilization optimization device. The compression system compresses air to obtain high-pressure air. The expansion system uses first heat-conducting oil to heat the high-pressure air to drive the expander set to generate power. The waste heat recovery system causes the hot water in the hot water tank and the second heat-conducting oil generated by heating the high-pressure air to flow into the evaporator to drive the turbine expander to generate power by using the steam generated by the evaporator. Thus, the problems of low energy utilization efficiency and insufficient utilization of waste heat mentioned in the background art are solved, the overall conversion efficiency of the system is improved, and energy loss is reduced.

[0038] Specifically, Figure 1 A structural schematic diagram of the compression air energy storage system energy cascade utilization optimization device provided by the embodiment of the present application is shown.

[0039] As Figure 1 shown, the compression air energy storage system energy cascade utilization optimization device 10 comprises a compression system 100, an expansion system 200 and a waste heat recovery system 300.

[0040] The compression system 100 is connected with the waste heat recovery system 300. The compression system 100 is used to compress air to a preset high-temperature and high-pressure state to obtain high-pressure air, and store the high-pressure air in a gas storage 103. The expansion system 200 is connected with the gas storage 103. When the high-pressure air in the gas storage 103 flows into the expansion system 200, the expansion system 200 uses first heat-conducting oil to heat the high-pressure air to drive the expander set 205 to generate power. The waste heat recovery system 300 is connected with the expansion system 200. The waste heat recovery system 300 is used to cause the cold water to flow into the hot water tank 307 after absorbing the heat generated in the compression process when the compression system 100 compresses air to a preset high-temperature and high-pressure state, and cause the hot water in the hot water tank 307 and the second heat-conducting oil generated by heating the high-pressure air to flow into the evaporator 302 to drive the turbine expander 301 to generate power by using the steam generated by the evaporator 302. The temperature of the second heat-conducting oil is lower than that of the first heat-conducting oil.

[0041] The preset high-temperature and high-pressure state can be a temperature interval and a pressure interval preset by a person skilled in the art according to actual conditions, which is not specifically limited here.

[0042] Specifically, as Figure 1As shown, the compression system 100 comprises: a motor set 101 for driving a compressor set 102, the motor set 101 being connected with the compressor set 102; the compressor set 102 comprises at least one stage of compressor, through which the air is compressed to a preset high-temperature and high-pressure state; a gas storage 103 connected with the compressor set 102, the gas storage 103 being used for storing the high-pressure air.

[0043] Further, in some embodiments, the expansion system 200 comprises: a cold oil tank 201 for storing third heat-conducting oil, wherein the temperature of the third heat-conducting oil is lower than the temperature of the second heat-conducting oil; a solar heat collector 202, an input end of the solar heat collector 202 being connected with an output end of the cold oil tank 201, the solar heat collector 202 being used for heating the third heat-conducting oil flowing out of the cold oil tank 201 to obtain the first heat-conducting oil; a hot oil tank 203, an input end of the hot oil tank 203 being connected with an output end of the solar heat collector 202, the hot oil tank 203 being used for storing the first heat-conducting oil; an intermediate heater set 204, an input end of the intermediate heater set 204 being connected with an output end of the hot oil tank 203, the intermediate heater set 204 being used for heating the high-pressure air by using the first heat-conducting oil flowing out of the hot oil tank 203 to drive the expander set 205 to do work and generate electricity. In addition, the expansion system 200 of the embodiment of the application further comprises a reheater 207 for preheating the air at the outlet of the expansion process gas storage.

[0044] For example, the temperature range of the first heat-conducting oil can be 330-350℃, the temperature range of the second heat-conducting oil can be 200-240℃, and the temperature range of the third heat-conducting oil can be 160-180℃, which are not limited herein.

[0045] Further, in some embodiments, the expansion system 200 further comprises: an expander set 205, the expander set 205 being connected with the intermediate heater set 204, the expander set 205 comprising at least one stage of expander; a throttle valve 206, an input end of the throttle valve 206 being connected with an output end of the gas storage 103, and an output end of the throttle valve 206 being connected with the expander of the first stage of the expander set 205. Wherein, the expanders in the expander set of the embodiment of the application can all be turbine expanders, which are not limited herein.

[0046] It should be noted that the number of intermediate heaters of the intermediate heater set 204 is the same as the number of expanders of the expander set 205, and the intermediate heaters of the intermediate heater set 204 and the expanders of the expander set 205 are arranged in sequence and are spaced apart. In addition, Figure 1The number of intermediate heaters (2 intermediate heaters, i.e. the first intermediate heater H4 and the second intermediate heater H5) in the intermediate heater group 204 and the number of expanders (2 expanders, i.e. the first expander TB1 and the second expander TB2) in the expander group 205 are only exemplary and not as a limitation to the present application, and those skilled in the art can set the number of intermediate heaters in the intermediate heater group 204 and the number of expanders in the expander group 205 according to actual conditions, which are not specifically limited herein.

[0047] Further, in some embodiments, the waste heat recovery system 300 comprises: a turbo expander 301; an evaporator 302, a first input end of the evaporator 302 is connected with the hot water tank 307, a second input end of the evaporator 302 is connected with an output end of the intermediate heater group 204, an output end of the evaporator 302 is connected with an input end of the turbo expander 301, and the evaporator 302 is used to convert the hot water and the second heat conducting oil into steam to drive the turbo expander 301 to generate power; a condenser 303, an input end of the condenser 303 is connected with an output end of the turbo expander 301, and the condenser 303 is used to condense the exhaust steam of the turbo expander 301 into saturated liquid; and a working medium pump 304, an input end of the working medium pump 304 is connected with an output end of the condenser 303, an output end of the working medium pump 304 is connected with a third input end of the evaporator 302, and the working medium pump 304 is used to re-pressurize the condensed saturated liquid and transmit it to the evaporator 302.

[0048] Further, in some embodiments, the waste heat recovery system 300 further comprises: an inter-stage cooler group 305, the number of inter-stage coolers in the inter-stage cooler group 305 is the same as the number of compressors in the compressor group 102, and the inter-stage coolers in the inter-stage cooler group 305 are arranged between the compressors in the compressor group 102 in an interval manner, and the inter-stage coolers in the inter-stage cooler group 305 are connected in series. It should be noted that, Figure 1 The number of inter-stage coolers (3 inter-stage coolers, i.e. the first inter-stage cooler H1, the second inter-stage cooler H2 and the third inter-stage cooler H3) in the inter-stage cooler group 305 and the number of compressors (3 compressors, i.e. the first compressor CP1, the second compressor CP2 and the third compressor CP3) in the compressor group 102 are only exemplary and not as a limitation to the present application, and those skilled in the art can set the number of inter-stage coolers in the inter-stage cooler group 305 and the number of compressors in the compressor group 102 according to actual conditions, which are not specifically limited herein.

[0049] In addition, the expansion system 200 of the present application further comprises a cold water tank 306 and a heat exchanger 308, wherein the cold water tank is used to store the cold water transmitted to the inter-stage cooler group 305, and the heat exchanger 308 is used to heat the cold water with the remaining heat after the waste heat recovery process for use by the surrounding residents.

[0050] The working principle of the energy gradient utilization optimization device of the compressed air energy storage system is introduced below.

[0051] Specifically, in the energy storage process, the motor set 101 drives the compressor set 102 to compress air into high-pressure air reaching a preset high-temperature and high-pressure state by using off-peak electricity or abandoned wind and light electricity or low-grade electricity.

[0052] Further, in the energy release process, on the one hand, the third heat-conducting oil from the cold oil tank 201 is heated to a target high-temperature state by the solar heat collector 202 and then flows into the hot oil tank 203 for storage.

[0053] Further, in the waste heat recovery process, the second heat-conducting oil after heat exchange of the intermediate heater in the energy release stage and the hot water in the hot water tank generated in the compression stage jointly flow into the evaporator 302 to provide heat for the waste heat recovery system.

[0054] According to the energy gradient utilization optimization device of the compressed air energy storage system, the compressed system compresses air to obtain high-pressure air, the expansion system heats the high-pressure air by using the first heat-conducting oil to drive the expansion machine set to generate power, and the waste heat recovery system causes the hot water in the hot water tank and the second heat-conducting oil generated by heating the high-pressure air to flow into the evaporator to drive the turbine expander to generate power by using the steam generated by the evaporator.

[0055] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, 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 appropriate manner in any one or N embodiments or examples. In addition, a person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples, without contradiction.

[0056] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0057] Although the embodiments of the present application have been shown and described above, it is understood that the above-described embodiments are exemplary and cannot be understood as limiting the present application, and a person skilled in the art can make changes, modifications, replacements and modifications to the above-described embodiments within the scope of the present application.

Claims

1. An optimization device for the cascade utilization of energy in a compressed air energy storage system, characterized in that, The device includes a compression system, an expansion system, and a waste heat recovery system, wherein, The compression system is connected to the waste heat recovery system. The compression system is used to compress air to a preset high temperature and high pressure state to obtain high-pressure air, and to store the high-pressure air in a gas storage tank. The expansion system is connected to the gas storage tank. When high-pressure air from the gas storage tank flows into the expansion system, the expansion system uses a first heat transfer oil to heat the high-pressure air in order to drive the expander unit to generate electricity. The waste heat recovery system is connected to the expansion system. When the compression system compresses the air to a preset high temperature and high pressure state, the waste heat recovery system uses cold water to absorb the heat energy generated during the compression process and then flows into a hot water tank. The hot water in the hot water tank and the second heat transfer oil generated by heating the high pressure air flow into the evaporator, so as to use the steam generated by the evaporator to drive the turbine expander to do work and generate electricity. The temperature of the second heat transfer oil is lower than the temperature of the first heat transfer oil.

2. The apparatus according to claim 1, characterized in that, The compression system includes: An electric motor assembly for driving a compressor unit, the electric motor assembly being connected to the compressor unit; The compressor unit includes at least one stage compressor, which compresses air to a preset high temperature and high pressure state. The gas storage tank is connected to the compressor unit, and the gas storage tank is used to store the high-pressure air.

3. The apparatus according to claim 1, characterized in that, The expansion system includes: A cold oil tank is used to store a third heat transfer oil, wherein the temperature of the third heat transfer oil is lower than the temperature of the second heat transfer oil; A solar collector, the input end of which is connected to the output end of the cold oil tank, is used to heat the third heat transfer oil flowing out of the cold oil tank to obtain the first heat transfer oil; A hot oil tank, the input end of which is connected to the output end of the solar collector, is used to store the first heat transfer oil; An intermediate heater assembly, the input end of which is connected to the output end of the hot oil tank, is used to heat the high-pressure air using the first heat transfer oil flowing out of the hot oil tank, so as to drive the expander unit to do work and generate electricity.

4. The apparatus according to claim 3, characterized in that, The expansion system further includes: An expander unit, the expander unit being connected to the intermediate heater unit, the expander unit comprising at least one stage expander; A throttle valve, the input end of which is connected to the output end of the gas storage tank, and the output end of which is connected to the first stage expander of the expander unit.

5. The apparatus according to claim 4, characterized in that, The number of intermediate heaters in the intermediate heater group is the same as the number of expanders in the expander group.

6. The apparatus according to claim 5, characterized in that, The intermediate heater of the intermediate heater group is spaced apart from the expander of the expander group.

7. The apparatus according to claim 1, characterized in that, The waste heat recovery system includes: Turbine expander; An evaporator, wherein the first input end of the evaporator is connected to the hot water tank, the second input end of the evaporator is connected to the output end of the intermediate heater group, and the output end of the evaporator is connected to the input end of the turbine expander. The evaporator is used to convert the hot water and the second heat transfer oil into steam to drive the turbine expander to do work and generate electricity. A condenser, the input end of which is connected to the output end of the turbine expander, is used to condense the exhaust gas vapor discharged from the turbine expander into a saturated liquid; A working fluid pump, the input end of which is connected to the output end of the condenser, and the output end of which is connected to the third input end of the evaporator, is used to repressurize the condensed saturated liquid and deliver it to the evaporator.

8. The apparatus according to claim 7, characterized in that, The waste heat recovery system also includes: An interstage cooler group, wherein the number of interstage coolers in the interstage cooler group is the same as the number of compressors in the compressor group.

9. The apparatus according to claim 8, characterized in that, The interstage coolers of the interstage cooler group are spaced apart from the compressors in the compressor group.

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