RU2783176C2 - Method and devices for energy accumulation with obtaining cryogenic liquids, energy storage, and its release, using different heat sources at generation stage - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: invention relates to accumulation and storage of energy; it can be used for adjustment of power of large generating stations, demand management, and other applications for generation, networks, consumers. The method includes following stages: purification of atmospheric air, its compression with reduction in an air temperature at an output of each compression stage to a temperature close to an ambient temperature, cooling to a temperature of 100 K, separation of compressed air into gas and liquid phases; storage of a liquid fraction in a cryogenic tank; release of energy during generation.

EFFECT: simplification of a liquefaction cycle with cold recovery at a charging stage, increase in the general efficiency, increase in a volume and density of accumulated energy, increase in a cycling resource.

41 cl, 7 dwg

Description

The invention relates to the field of energy, and can be used, in particular, for the accumulation and storage of energy, power control of large generating stations (including nuclear), renewable energy (the operation of the storage in combination with wind turbines, solar power plants and other non-permanent renewable energy sources ), hybrid power plants, peak and stationary gas turbine plants, smoothing load peaks, backup power supply, network regulation of power consumption (including daily), demand management and other applications for generation, networks, consumers.

The problem of accumulation of electric energy is especially relevant in recent years. There is no systematic solution to the problem of energy storage in the Russian Federation today, both from the side of generation and the network, and from the side of the consumer. Power regulation during periods of “failure” of energy consumption and peak hours is difficult for steam thermal power plants and nuclear power plants for a number of reasons; pumped storage plants (PSPP) and peak generation by gas turbine units (GTP) are used for regulation. Over the next 5-10 years, the expected commissioning of large intermittent renewable energy generation capacity will exacerbate grid irregularities. This will lead to a forced decrease in the installed capacity utilization factor (ICUF), associated with the shutdown of renewable energy sources (RES) at the time of excess generation, where the amount of power generated by them is significant for the network (more than 20%). Autonomous energy centers are forced to reserve capacity using expensive hydrocarbon fuel, which leads to an increase in electricity tariffs and the need for subsidies.

Among the known large-scale energy storage methods, mention should be made of hydrogen energy storage, pumped storage, compressed air energy storage, thermal energy storage systems, and cryogenic energy storage.

Hydrogen energy storage devices have a high energy density (800–10,000 Wh/kg), but they inevitably suffer large losses in the process of hydrogen production and transportation. The efficiency of hydrogen energy storage systems usually reaches no more than 20-35% at high capital costs, which negatively affects the payback period.

Hydro storage power plant (PSPP) is the most established energy storage technology. The pumped storage power plant accumulates potential hydraulic energy by pumping water from the lower reservoir to an elevated pressure reservoir (charging phase), using cheap electricity during periods of low demand. HPSP has high efficiency, relatively low operating costs. The need for two large tanks at different levels limits the use of pumped storage power plants, especially near large cities, and usually leads to very high capital costs.

Compressed Air Storage Systems (CAES) use the potential energy of compressed air to store electricity. Inexpensive electricity is used to compress air, which is then stored in a large reservoir (usually a special underground cavern). During the discharge phase, air is released from the reservoir, heated and then expanded through a turbine that drives a generator to generate electricity. CAES theoretically provides relatively high efficiency and low capital cost for the electrical energy storage. However, the application of CAES is limited by the requirements of building large compressed air storage tanks.

Thermal energy storage systems (SATE) were considered for use at nuclear power plants (for example, RU 2672559 C1). In the last 10 years, several scientific groups have carried out a fairly deep study of the possibility of using STE at nuclear power units, but the process has not been developed, mainly due to the required intervention in the operation of the turbine, and the density of the stored energy of thermal storage is low.

Rechargeable Li-Ion batteries store electricity as potential chemical energy, can quickly respond to load changes, improving system stability. They are not geographically restricted as they are for HPS and CAES, however they are relatively expensive, their efficiency degrades over time (about 6.9% degradation per 1000 cycles), which limits their useful life.

Cryogenic energy storage systems (CSES) have been known since the late 70s [E. M. Smith et al.; "Storage of Electrical Energy Using Supercritical Liquid Air" and Discussion thereof: Proc Instn Mech Engrs Vol 191 27/77, p. 289-298, D57-D65; 1977]. WO2007-096656A1 and GB1100569.1 disclose cryogenic energy storage devices that use a cryogenic liquid such as liquid air or liquid nitrogen as an energy storage medium. The Integrated Cryogenic Energy Storage System (CES or CES) cycle allows for the extraction of cold energy stored during the evaporation and heating of the cryogen during the energy regeneration (discharge) phase, which is stored and then used during the charging phase to increase the efficiency of liquid air production - the concept , known as recovery (reuse) of cold. A number of publications describe such CES devices, for example, US 6920759 B2. The main advantages of CVNS include high energy density (120-200 Wh / l) and compactness, the ability to place where needed.

The following solutions are known from the prior art for the storage of electrical energy.

Known industrial energy storage system RU 2699855 C1, which includes at least one energy cell. The energy cell contains a plurality of weights, a carriage, a trolley, a rope and a main drive. The system is made with the possibility of vertical movement of goods and fixation of goods in the energy cell either in the upper position or in the lower position. The system is charged by moving at least one of the plurality of weights from the bottom position to the top position. The system is discharged when at least one of the plurality of weights is moved from an up position to a down position. The known energy storage system belongs to the group of gravitational storage devices. The efficiency of this group of methods is one of the highest among others, but it also has the disadvantages of gravitational energy storage methods: bulkiness and low stored energy density (Wh/kg), determined by the weight of the load. The discharge time of such systems at a height of tens of meters is minutes, so their large-scale and cost-effective implementation is unlikely and requires deep study.

A known method of accumulation of electrical energy, which is based on the conversion of electricity into heat at the time of charging the system, the reverse transformation at the time of discharging. An example of such a solution is the well-known thermoelectric energy storage system and the thermoelectric energy storage method (Patent RU 2522262 C2). The known invention, as described by the authors, is based on a heat pump cycle in the charging stage (conversion of electricity into heat) and a heat engine cycle in the discharge stage (reverse conversion). It is an object of the known invention to provide a thermoelectric energy storage system capable of converting electrical energy into thermal energy, which is to be stored and converted back into electrical energy with improved closed cycle efficiency. This problem in the known invention is solved with the help of a system and method of accumulating thermoelectric energy. According to a preferred embodiment of the known invention, the thermal storage medium is water. This imposes restrictions on the maximum heating temperature of the working fluid at the moment of discharge and, accordingly, on the overall efficiency. As the inventors point out, if, for example, the heat stored in a thermoelectric energy storage system is generated by resistance heaters, then such a system is characterized by a closed cycle efficiency of about 40%. The known method is aimed at increasing efficiency, but losses during the conversion of electricity into heat and vice versa are inevitable, so the overall efficiency will not be high even with additional measures taken by the authors of the known invention. The economic feasibility of such energy storage devices is questionable.

Known energy storage system that improves efficiency by reducing energy losses during compression and liquefaction of gas (Patent SU 1578369 A1). During the charging process, the gas is compressed in the compressor and cooled in the cooler by the reverse flow of cold air from the phase separator. The work of the expander in the liquefaction cycle in the known method is spent on heating the coolant in the appropriate tank. For the coolant, a second tank is provided, combined with the first they form a closed circulation circuit. Liquefied gas during operation accumulates in a separate third tank. As the system discharges, the liquefied gas is pumped into the heat engine cooler where it evaporates. Next, the gas is heated in two heaters. Heat is supplied to two heaters in the generation chain from the environment. The final heating of the gas is carried out in the third heater by the coolant supplied from the tank, where the heat was accumulated during liquefaction (charging) using the expander, to the second tank, where the cooled coolant is accumulated. The heated gas is expanded in a gas turbine to generate electricity. A significant disadvantage of the known method is that the cold of the cryogenic liquid is not stored and reused in the liquefaction cycle, but is actually released into the atmosphere, which leads to a deterioration in the specific indicators of the liquefaction cycle and the overall efficiency of the system as a whole. Secondly, the expander in the liquefaction cycle is known to reduce the work of the compressors. In the known method, the operation of the expander is converted into electrical, and the heat carrier is heated by an electric heater. Such a technological chain leads to an increase in heat losses. Liquid heat storage is limited by the maximum temperature, and therefore the efficiency of such a system is limited.

A cryogenic storage system is known (Patent RU 92093 U1) consisting of a series-connected energy source, a cryogenic refrigerator with air purification and dehydration devices, a gas separator and a heat exchanger of the cooling system of the refrigerator, a thermally insulated tank for storing cryogenic liquid, characterized in that the storage tank cryogenic liquid is connected to a cryogenic engine connected to an autonomous energy generator, and the exhaust line of the cryogenic engine is connected to a switch connected to the inlet to the refrigeration machine or to the atmosphere. The outlet of the heat exchanger of the refrigerating machine is connected to the heat exchanger for the hot water supply system of energy consumers, and the exhaust line of the cryogenic engine is connected to the cold heat exchanger of the refrigeration system of consumers before entering the switch. Liquefied atmospheric nitrogen is used as the stored cryogenic liquid. The known system does not use external heat at the generation stage to preheat nitrogen before expansion (in this case, by a cryogenic engine), which significantly reduces the amount of electrical energy generated, and, as a result, reduces the overall efficiency. The heat from the compression stage in the liquefaction stage is transferred to an external consumer in the form of hot water, which also reduces the amount of energy produced, since this heat could be transferred to nitrogen before expansion. The authors of the well-known system for expanding nitrogen after the pump and generating electricity chose a cryogenic engine - an expensive and complex unit. In this case, the cold is taken after the engine and transferred to an external consumer, without its return to the liquefaction cycle, which increases the specific cost of liquefaction. Also, the authors of the well-known system proposed to return the stream of purified nitrogen after the selection of cold to the liquefaction cycle, but these two processes cannot be combined in time, otherwise the system will not work as an electric energy accumulator.

Known compressor heat recirculation system WO 2019/158921. In a well-known invention, it is proposed to recover heat from the compression stage in the air liquefaction cycle, accumulate it and store it, then, at the right time, use the accumulated heat to heat the air sent for generation. The well-known system is based on an air liquefaction cycle with a recirculation compressor. There are many liquefaction cycles that can potentially be used in CVNS, but this cycle, taken as the main one in the known system, is difficult to implement. The stability and efficiency of the known system in real conditions may differ from the calculated one for the worse.

Known method and device for energy storage US 10138810 B2, which is the closest analogue to the claimed invention. The known invention describes cryogenic energy storage systems, and, in particular, methods for the selection and reuse of cold energy. The described systems make it possible to effectively select, store and use cold thermal energy obtained in the process of discharging a cryogenic energy storage system. The stored cold energy can be reused in any associated process, for example to increase the efficiency of cryogen production, to increase the efficiency of liquid natural gas production and/or to provide freezing. The systems are such that cold energy can be stored at very low pressures, cold energy can be extracted from various components of the system, and/or cold energy can be stored in more than one thermal store. The main disadvantage of the known invention is that for the liquefaction cycle, the authors propose a complex cycle, including the use of an air recirculation compressor, turboexpanders connected to compressors, inside the liquefaction cycle. However, there are a lot of options for liquefaction cycles, the scheme with air recirculation and integration of turboexpanders with compressors is difficult to implement, limits the scope of this cycle in terms of pressures, and the actual efficiency results may differ from the calculated ones. Among the shortcomings of the generation stage, one should mention a rather large amount of cold lost with the air emitted into the atmosphere.

The technical problem to be solved by the claimed invention is to create a method and device for energy storage with the production of cryogenic liquids and the use of various heat sources at the generation stage with a low cost of energy intensity and a large cycling resource for networks, generation and consumers (including . industrial enterprises), based on simpler liquefaction cycles with cold recovery with comparable energy costs in comparison with foreign and domestic counterparts, increasing the generation capacity using various heat sources, increasing the overall efficiency and availability of CVNS.

This technical problem is solved by optimizing the cycles of liquefaction (charging) and generation (discharging) of the CVNS, which makes it possible to simplify the cycle of air liquefaction and the device as a whole.

technical result, achieved when using the claimed invention, consists in simplifying the liquefaction cycle with cold recovery at the stage of charging the CVNS, increasing the overall efficiency of the CVNS, including by increasing the generation power using various heat sources, increasing the volume and density of the stored energy, and increasing the cycling resource.

The technical problem is solved and the technical result is achieved by the fact that in the method of energy accumulation with the production of cryogenic liquids, energy storage and its release using various heat sources at the generation stage:

- atmospheric air is purified, at least, from mechanical impurities, water and carbon dioxide;

- purified atmospheric air is compressed in one or more stages to a pressure that is optimal for the selected liquefaction cycle with a decrease in air temperature at the outlet of each compression stage to a temperature close to the ambient temperature;

- compressed and cooled to a temperature close to ambient temperature, the air is cooled to approximately 100 K;

- cooled to a temperature of approximately 100 K, compressed air under pressure through a throttle valve is fed into the phase separator for phase separation;

- in the gas separator, the cooled air is separated into gas and liquid phases;

- from the phase separator, the gas phase is sent to the atmosphere after cooling (heat extraction) of the inlet compressed air flow after the cooler of the last compression stage, and the liquid fraction is sent to the storage stage in a cryogenic tank;

- the liquid fraction is stored in a cryogenic tank for the required period of time;

- if there is a need for energy generation, the cryogenic liquid (liquid fraction of air) is compressed by a cryogenic pump, preferably to a pressure of 35 to 256 atm;

- after which the compressed liquid air is passed through at least one first heat exchanger, while passing through which it is heated with the selection of cold into the cold storage system, then the air is passed through at least one second heat exchanger, where it is heated with the supply of heat extracted from heat sources;

- before expansion in turbo expanders in one or several stages, in case of using several stages, air is heated before each stage, while the exhaust from the last expansion stage using an additional heat exchanger is directed to heat (gives off residual heat) the air flow entering the generation stage between the last heat exchanger of the cold storage system and before the first heat supply heat exchanger before expansion, after the heat is transferred to the inlet air flow, the environmentally friendly exhaust in the form of gaseous air is released into the atmosphere.

The air temperature at the outlet of each compression stage is reduced by cooling, while the air temperature at the outlet of each compression stage can be reduced by taking heat to a heat accumulator.

Purified air can be compressed up to 150 atm, while in order to increase the efficiency of the liquefaction process, compressed and cooled to a temperature close to ambient temperature, the air is cooled to approximately 100 K using the cold accumulated at the generation stage and the reverse flow of the gas phase from the phase separator.

Purified air can be compressed up to 70 atm., while in order to increase the efficiency of the liquefaction process, cooled to a temperature close to the ambient temperature, the air is sent to the flow divider, where part of the air (X ₁ ) from the initial flow rate is transferred to cooling with the cold accumulated at the stage generation, and the remaining part (1-X ₁ ) is transferred for cooling by the flow leaving the turboexpander and the gas phase of the separator, after which this part of the air (1-X ₁ ) from the initial flow rate is transferred for separation to the second flow divider, in which part from the incoming air (X ₂ ) is directed to expansion in the turboexpander, then mixed at the outlet of the turboexpander with the gas stream from the phase separator, after which their mixture cools the stream (1-X ₁ -X ₂ ) leaving the second flow divider and entering the second flow mixer, which mixes the flows X ₁ and the flow (1-X ₁ -X ₂ ), from where the cooled compressed flow (1-X ₂ ) with a temperature of about 100 K is sent through a choke in phases new separator. The ratio of costs X ₁ :(1-X ₁ ) is about 0.6:0.4 of that included in the divider, and the ratio of costs X ₂ :(1-X ₁ -X ₂ ) is about 0.35:0.65 of included in the flow divider (1-X ₁ ).

The purified air can be compressed up to 50 atm., while in order to increase the efficiency of the liquefaction process, cooled to a temperature close to the ambient temperature, the air is sent to the flow divider, where part of the air (1-X ₁ ) from the initial flow rate is transferred to cooling by the cold accumulated at the generation stage, and part of the air X ₁ is transferred to indirect cooling by an auxiliary closed mixture circuit, in which the mixture may contain methane, ethane, propane, I-pentane, nitrogen or other components, including compression of the mixture, cooling to ambient temperature, cooling to about 100 K by reverse flow of the mixture, expansion of the mixture through the throttle, cooling of the forward flow of the mixture by reverse and air flow X ₁ , return of the mixture to compression to repeat the mixture auxiliary cycle, then after cooling, the two flows (1-X ₁ ) and X ₁ are mixed, total a cooled compressed flow with a temperature of about 100 K is sent through a throttle to a phase separator. In this case, the ratio of costs X ₁ :(1-X ₁ ) can be about 0.5:0.5 of the flow rate entering the divider, and the mixture in the mixture circuit can have the following composition: 32% - methane, 15% - ethane, 15 % - propane, 21% - I-pentane, 17% - nitrogen.

The time during which the energy is accumulated exceeds the time during which the stored energy is released.

Energy generation can be carried out in two stages, while the air is heated in front of the turboexpander by the flue gas flow of the gas turbine before being released into the atmosphere, fuel is supplied at the outlet of the turboexpander before the gas turbine.

To heat the air before expansion at the generation stage, one of the following heat sources is used: direct combustion of fuel in air in a turbine, waste heat from industrial enterprises, landfill gas combustion, exhaust gas from gas turbine plants, including peak gas, steam extraction from a nuclear power plant or thermal power plant, heating circuit nuclear power plant or thermal power plant.

The technical problem is solved and the technical result is also achieved by the fact that the device designed to implement the claimed method when compressing purified air to 150 atm includes an air purification unit from mechanical impurities and water purification, a CO ₂ removal unit, N compressor stages for compressing purified air , where N is equal to or more than 1, N heat exchangers designed to cool compressed air, a three-way heat exchanger, a system for accumulating and transferring cold to a liquefaction cycle, a throttle valve, a phase separator, a cryogenic tank for storing energy in the periods between energy accumulation and its release at the stage generation, liquid air cryogenic pump, at least one heat exchanger for evaporation and removal of cryogen cold to the cold storage system, exhaust heat recuperator of the last stage of the turboexpander, heat supply system, M heat exchangers for heating the air before its expansion in the turboexpander stages using the system under heat water, M stages of the turboexpander, wherein the air purification unit is connected to the CO ₂ removal unit, the output of the CO ₂ removal unit is connected to the inlet of the compressor, the outlet of which is connected to the inlet of the heat exchanger, the outlet of which is connected to the first inlet of the three-way heat exchanger, the second inlet of which is connected to the outlet of the system for accumulating and transferring cold to the liquefaction cycle, and the third inlet is connected to the outlet of the phase separator, the inlet of which is connected through a throttle valve to the first outlet of the three-way heat exchanger, the second outlet of which is connected to the inlet of the system for accumulating and transferring cold to the liquefaction cycle, and the third outlet is intended to remove air from the cryoblock, the second output of the phase separator, designed to remove liquid air, is connected to a cryogenic tank, the output of which is connected through a cryogenic pump to a heat exchanger designed to evaporate and take cryogen cold into the cold accumulation system, the output of the said heat exchanger is connected to the first inlet recuper exhaust heat source of the last stage of the turboexpander, the recuperator is connected in parallel to the heat supply system.

The technical problem is solved and the technical result is also achieved by the fact that the device designed to implement the claimed method when compressing purified air to 70 atm includes an air purification unit from mechanical impurities and water purification, a CO ₂ removal unit, N compressor stages for compressing purified air , N first heat exchangers designed to cool compressed air, where N is equal to or greater than 1, a cold storage and transfer system, a phase separator, a turbo expander, a cryogenic tank for storing energy in the periods between energy accumulation and its release at the generation stage, the first flow divider, the second heat exchanger is designed to cool the flow X ₁ using the cold accumulated at the generation stage in the cold storage and transfer system, the third heat exchanger is designed to cool the flow (1-X ₁ ) by the return flow of the gas phase from the phase separator and the flow after expansion, the second flow divider, fourth heat exchanger designed to cool the stream (1- X ₁ - X ₂ ) with the reverse gas stream from the phase separator and the expansion stream, the first mixer of the gas stream, designed to mix the streams from the phase separator and the outlet of the turbo-expander X ₂ , the second mixer, designed to mix the streams X ₁ and (1- X ₁ - X ₂ ), a throttle designed to expand the cooled flow (1-X ₂ ) of the phase separator, the fifth heat exchanger, designed to evaporate and take cryogen cold into the cold accumulation system, exhaust heat recuperator of the last stage of the turboexpander , a heat supply system, M heat exchangers for heating air before expanding it in the turboexpander stages using a heat supply system, M turboexpander stages, while the outlet of the air purification unit from mechanical impurities and water is connected to the inlet of the CO ₂ removal unit, the outlet of which is connected to compressor inlet for compressing purified air, connected by outlet to inlet of the first heat exchanger, the outlet of the first heat exchanger is connected to the inlet of the first flow divider, the first outlet of which is connected to the inlet of the second heat exchanger, the second outlet of the first flow divider is connected to the first inlet of the third heat exchanger, the first outlet of the third heat exchanger is connected to the inlet of the second flow divider, the first outlet of which is connected to turbo-expander inlet, the second outlet is designed to remove air from the cryoblock, the third outlet is connected to the first inlet of the fourth heat exchanger, the second inlet of which is connected to the outlet of the gas flow mixer from the phase separator and the turbo-expander outlet X ₂ , the first inlet of the second mixer is connected to the outlet of the turbo-expander, the second inlet of the second gas flow mixer is connected to the first outlet of the phase separator, the second outlet of the phase separator is connected to the inlet of the cryogenic tank, the inlet of the phase separator is connected through a throttle to the outlet of the first mixer, the first inlet of which is connected to the outlet of the second heat exchanger, and the second inlet is connected to the outlet of the fourth heat exchanger, the coolant circuit of the cold accumulation system is connected in parallel to the second heat exchanger, the outlet of the cryogenic tank through the cryogenic pump is connected to the fifth heat exchanger, the outlet of the fifth heat exchanger is connected to the first inlet of the exhaust heat recuperator of the last stage of the turboexpander, the recuperator is connected in parallel to the supply system warmth.

The technical problem is solved and the technical result is also achieved by the fact that the device designed to implement the claimed method when compressing purified air to 50 atm includes an air purification unit from mechanical impurities and water, a CO ₂ removal unit, at least one compressor stage for compression purified air, at least one first heat exchanger for cooling compressed air and transferring heat to a heat accumulator, the first flow divider, the second and third heat exchangers designed to cool the flow (1-X ₁ ) using the cold accumulated at the generation stage in the accumulation system and cold transfer, a three-way heat exchanger designed to cool the flow X ₁ with an auxiliary mixture cycle, a compressor designed to compress the mixture, a fourth heat exchanger designed to cool the mixture to ambient temperature, the first throttle valve, a mixer in which the flows X ₁ and (1 -X ₁ ), second throttle valve pan, phase separator, cryogenic tank, fourth heat exchanger, wherein the outlet of the air purification unit from mechanical impurities and water is connected to the inlet of the CO ₂ removal unit, the outlet of which is connected to the inlet of a compressor designed to compress the purified air, the outlet of said compressor is connected to the inlet of the first heat exchanger, the outlet of which is connected to the inlet of the first flow divider, the first outlet of the first divider is connected to the first inlet of the second heat exchanger, the second outlet of the first divider is connected to the first inlet of the three-way heat exchanger, the first outlet of which is connected to the first inlet of the mixer, the second outlet of the three-way heat exchanger is connected to the inlet a compressor designed to compress the mixture, the outlet of which is connected through the fourth heat exchanger to the third inlet of the three-way heat exchanger, the third outlet of the three-way heat exchanger is connected through the first throttle valve to the second inlet of the three-way heat exchanger, the mixer outlet is through the second throttle valve an is connected to a phase separator, the first outlet of which is connected to the inlet of the cryogenic tank, the second outlet is connected to the first inlet of the fifth heat exchanger, the first outlet of the fourth heat exchanger is connected to the first inlet of the third heat exchanger, air is removed from the cryoblock through the second outlet of the fourth heat exchanger, the outlet of the cryogenic tank is through the cryogenic the pump is connected to the fifth heat exchanger, the outlet of the fifth heat exchanger is connected to the first inlet of the exhaust heat recuperator of the last stage of the turboexpander, the recuperator is connected in parallel to the heat supply system.

In each of the devices described above, the compressor may have N stages, where N=2 or N=3 or N=4, the cryogenic tank may be made with vacuum thermal insulation, the turboexpander may have M stages, where M=2 or M=3 or M =4.

Each device may include a series of heat exchangers in series.

The system of accumulation and transfer of cold, which can be used in each device mentioned above, contains warm and cold methanol tanks, warm and cold propane tanks, heat exchangers and for indirect supply of cold to the liquefaction cycle by pumping methanol and propane from the cold tank to the warm tank, respectively, heat exchangers and for indirect extraction of cold from liquid air supplied to the generation by pumping propane and methanol from a warm tank to a cold tank, is located at the inlet and outlet of warm tanks.

The heat storage and transfer system that can be used in each device mentioned above includes a hot coolant tank and a warm coolant tank, as well as heat exchangers for extracting heat from the compression process or from another external source and heat supply heat exchangers before expansion, while as a heat carrier water or thermal oil or molten salts are used, pumping equipment is located at the inlet to the warm coolant tank and at the outlet of the warm coolant tank to operate in the heat transfer and withdrawal cycle, respectively.

The devices may additionally include a stabilizer of power generated by external energy sources. At the same time, two low-capacity Li-Ion batteries are used as a stabilizer for the power generated by external energy sources.

The above features of the invention are essential and are interconnected with the formation of a stable set of essential features sufficient to obtain the desired technical result.

The present invention is illustrated by specific examples of performance, which, however, is not the only possible one, but clearly demonstrates the possibility of achieving the desired technical result.

The use of heat taken from heat sources, which can be used as various external heat sources, such as direct combustion of fuel in air in a turbine, waste heat from industrial enterprises, landfill gas combustion, exhaust gas from gas turbine plants, including peak ones, steam extraction from a nuclear power plant or thermal power plant, the heating circuit of a nuclear power plant or thermal power plant, allows you to increase the generation capacity and the overall efficiency of the CVSS cycle - the discharge / charge cycle.

Due to the hardware chain for the liquefaction cycle presented in the method and device, the claimed invention is simpler in terms of the type of equipment used in comparison with analogues, since, in particular, it does not include combined compressors and turbo-expanders, a recirculation compressor, and is implemented mainly using equipment developed by the industry, which simplifies the implementation of CVNS for the energy industry, both Russian and foreign markets.

The high density of stored energy in the claimed invention is achieved by the main principle of SNEC: the accumulation of energy in the form of liquid cryogen, i.e. the density of liquid air (about 960 kg/m ³ ) makes it possible to accumulate large volumes of the working fluid in a compact form where it is required. This is one of the main advantages of CVD compared to other energy storage methods.

A large cycling resource is achieved in the claimed invention by using power equipment (compressors and turbines) designed for continuous, round-the-clock operation for a long time. At the same time, the peculiarity of the functioning of energy storage systems has a positive effect - work is not around the clock, but the alternate start of the liquefaction and generation cycle, usually for 8 hours at night and for a total of 4 hours during peak periods, respectively. It is the use of reliable power equipment, mastered by the industry, for the purposes of accumulation, storage and release of energy that makes it possible to achieve a large cycling resource (over 10,000 charge-discharge cycles). Also, a large cycling resource is achieved by a low percentage of degradation of the storage capacity for 1000 cycles. For example, in Li-Ion batteries, degradation is about 6.9% per 1000 cycles due to the specifics of this energy storage method. There are no elements in CSNE (since the principle of energy storage is not electrochemical), which can lead to degradation of such a level.

The essence of the claimed method and devices for its implementation is illustrated by the following drawings.

Fig. 1. Diagram of a device for implementing the claimed method by compressing purified air to 150 atm.

Fig. Fig. 2. Scheme of the device for the implementation of the liquefaction cycle by compressing purified air to 70 atm.

Fig. Fig. 3. Scheme of a device for implementing a liquefaction cycle by compressing purified air to 50 atm using an auxiliary mixed cycle and a scheme of a system for accumulating and supplying cold using liquid heat carriers.

Fig. 4. Scheme of the heat storage and transfer system for the claimed devices on the example of compressor heat storage, 2 compression stages, 2 generation stages.

Fig. 5. An example of a device diagram for implementing the claimed method with 2 compression stages, compression heat storage and 4 generation stages.

Fig. 6. An example of a device diagram for implementing the claimed method without compressor heat storage, using the heat of the gas turbine exhaust gas.

Fig. 7. An example of a diagram of a device for implementing the claimed method without compressor heat storage, with generation by a combination of a turboexpander and a gas turbine plant.

The choice of a liquefaction cycle for cryogenic energy storage systems is determined by several factors, but the main ones are: specific energy costs for obtaining 1 kg of the liquid phase, taking into account cold recovery and the degree of liquid output, the capital intensity of the equipment used to implement the cycle. At the same time, it is the choice of the operating pressure of the cycle that mainly affects the capital intensity of the liquefaction stage, since it is obvious that the compressor, pipelines and fittings for high pressures will be more expensive than for medium and low pressures. At the same time, an increase in pressure leads to an increase in the yield of the liquid phase, this is a well-known fact from cryogenic technology. In this regard, the optimization of liquefaction cycles using known methods of thermodynamic and CFD modeling consists in choosing the cold return point to the liquefaction cycle from the generation stage, selecting the operating pressure and hardware (compression schemes, a set of heat exchangers, flow dividers, etc.), which allows you to choose the optimal solution for energy costs and the degree of output of the liquid phase. In the future, a feasibility study of the developed scheme is carried out, including an assessment of the cost of equipment. The claimed invention presents three optimized liquefaction cycles: for high pressure (about 150 atm), medium pressure (up to 70 atm) and relatively low pressure (up to 50 atm). All of them are of interest, since, according to the results of optimization, they have comparable energy costs. The choice of a liquefaction cycle based on the results of a technical and economic analysis of optimal cycles is influenced by a set of initial parameters, since it largely depends on the power and energy intensity of the energy storage device being developed. Accordingly, optimization is in demand in the development of new SNECs.

A device for implementing the claimed method by compressing purified air up to 150 atm, the diagram of which is shown in Fig. 1, includes: air purification unit from mechanical impurities and water purification (drying) 1 by known methods, CO ₂ removal unit 2 by known methods, K ₁ ... K _N - compressor stages 3 for compressing purified air, TO ₁ ... TO _N - heat exchangers 4 for cooling compressed air or extracting heat and transferring it to a heat accumulator, where N is the number of compressor stages compression stages), three-way heat exchanger 5, cold storage and transfer system to the liquefaction cycle 6, throttle valve 7, phase separator 8, cryogenic tank (preferably with vacuum thermal insulation) 9, liquid air cryogenic pump 10, heat exchanger 11 (or group of successive heat exchangers) for evaporation and withdrawal of cold cryogen into the system of accumulation and transfer of cold 6 to the liquefaction cycle, the heat exchanger 12 of the exhaust heat of the last stage of the turboexpander 13, the heat supply system 14 (third-party or external of heat accumulated from the compression stage), heat exchangers 15 for heating the air before its expansion in the stages of the turbo expander 13 using the heat supply system 14, TD ₁ ... TD _M are the stages of the turbo expander 13, where M is the number of expansion stages (preferably M=2.. 4, the expansion ratio is defined as the initial expansion pressure in the degree (1/M)).

The operation of the device that implements the claimed method by compressing purified air to 150 atm is as follows. At the moment of failure of energy consumption, the charging (liquefaction) cycle of the device is started. At the same time, the air from the atmosphere is passed through the block for cleaning from mechanical impurities and removing moisture 1, then the purified air is passed through the block for removing CO ₂ 2, after which the air is supplied for compression through compressors 3 K ₁ ... K _N to the optimum pressure for the selected liquefaction cycle ( preferably up to 150 atm), where it is cooled after each stage in heat exchangers 4 TO ₁ ... TO _N in atmospheric coolers or using forced supply of a coolant (including with heat extraction to a heat storage device, which is not shown in Fig. 1), then compressed air is sent to a three-way heat exchanger 5, where it is cooled to approximately 100 K by the reverse flow of the gas phase from the phase separator 8 and the cold accumulated at the generation stage in the cold storage and transfer system 6, then the cooled compressed air is sent through the throttle valve 7 to the phase separator 8, from where the gas phase is sent to the three-way heat exchanger 5, and the liquid phase is sent to the liquid air storage stage. a (stored energy) into the cryotank 9. At the right time (for example, during the peak period of energy consumption), liquid air is compressed by a cryogenic pump 10 (up to a pressure of 35-256 atm) and fed into the heat exchanger 11 (or a group of successive heat exchangers) to evaporate the air and its heating, as well as the selection of cold by the system of accumulation and transfer of cold 6, then the air is sent to the heat exchanger 12 to extract the exhaust heat of the last stage, then to the heat exchanger 15 heating before the expansion stage TO _G1 . The air expands in the first stage of the turboexpander 13 TD ₁ , then it is passed through M heaters TO _GM and stages TD _M (preferably M=2..4, the expansion ratio is defined as the initial expansion pressure in the degree (1/M)), after exiting from the last stage, it is sent to the heat exchanger 12 to transfer heat to the incoming flow and is released into the atmosphere in the form of environmentally friendly clean air.

A device for implementing the claimed method by compressing purified air up to 70 atm. includes (Fig. 2) node 1 for air purification from mechanical impurities and purification from water (drying) by known methods, node 2 for CO ₂ removal by known methods, K ₁ ... K _N - compressor stages 3 for compressing the purified air to the optimum pressure for the selected cycle liquefaction (preferably 70 atm), TO ₁ ... TO _N - heat exchangers 4 for cooling compressed air or heat extraction and transfer to the heat storage, N - number of compressor stages 3 (preferably N=2..4, the compression ratio is determined as the final pressure (1/N), where N is the number of compression stages), the first flow divider 16, the heat exchanger 17 for cooling the flow X ₁ using the cold accumulated at the generation stage in the cold storage and transfer system 6, the heat exchanger 18 for cooling the flow (1 - X ₁ ) the reverse flow of the gas phase from the phase separator 8 and the flow after expansion, the second flow divider 19 to direct part of the flow X ₂ to the cryogenic turbo expander 20, the heat exchanger 21 for about cooling of the stream (1 - X ₁ - X ₂ ) by the reverse gas stream from the phase separator 8 and the expansion stream, the first mixer 22 of the gas stream from the phase separator 8 and the stream from the outlet of the cryogenic turboexpander 20 X ₂ , the second stream mixer 23 X ₁ and (1 - X ₁ - X ₂ ), throttle valve 7 for expanding the cooled flow (1-X ₂ ), phase separator 8, from where the liquid phase is sent for storage to the cryogenic tank 9, cryogenic tank 9, liquid air cryogenic pump 10, heat exchanger (or group of successive heat exchangers) 11 for evaporation and withdrawal of cryogen cold to the system of accumulation and transfer of cold 6 to the liquefaction cycle, recuperator 12 of the exhaust heat of the last stage of the turboexpander 13, heat supply system 14 (third-party or heat accumulated from the compression stage), heat exchangers 15 for heating air before its expansion in the stages of the turbo expander 13 using the heat supply system 14, TD ₁ ... TD _M are the stages of the turbo expander 13, where M is the amount of expansion stages (preferably M=2..4, the expansion ratio is defined as the initial expansion pressure to the power of (1/M)).

For the operation of the device, the preferred flow ratio X ₁ :(1-X ₁ ) is about 0.6:0.4 of that included in the divider, the preferred flow ratio X ₂ :(1-X ₁ -X ₂ ) is about 0.35:0 .65 from the flow entering the divider (1-X ₁ ).

The liquefaction of air (charging) in the specified device is carried out as follows. Atmospheric air is preliminarily purified by known methods, at least from mechanical impurities, water and carbon dioxide, then compression is carried out (the degree of compression is defined as the final compression pressure in the degree (1 / N), where N is the number of compression stages) into one or more stages to a pressure optimal for the selected liquefaction cycle (preferably up to 70 atm in 1-4 stages) with cooling or heat extraction to the heat accumulator at the outlet of each compression stage. After compression and cooling to a temperature close to the ambient temperature, the air is sent to the flow divider 16, where X ₁ is from the initial flow rate (the preferred ratio X ₁ :(1-X ₁ ) is about 0.6:0.4 from the air entering the divider ) is transferred for cooling with the cold accumulated at the generation stage, and (1-X ₁ ) is transferred for cooling with the stream leaving the cryogenic turboexpander 20 and the gas phase of the separator 8, then the stream (1-X ₁ ) is transferred for separation to the second flow divider 19, the flow X ₂ in the second flow divider 19 (the preferred ratio of flow rates X ₂ :(1-X ₁ -X ₂ ) is about 0.35:0.65 of the flow rate entering the divider (1-X ₁ )) is directed to the expansion in the cryogenic turboexpander 20, then mixed at the outlet of the cryogenic turboexpander 20 with the gas stream from the phase separator 8, after which the mixture cools the stream (1-X ₁ -X ₂ ) leaving the second stream divider 19 and entering the second stream mixer 23 , in which the stream X ₁ and the stream (1-X ₁ -X ₂ ), from where the cooled compressed stream (1-X ₂ ) with a temperature of about 100 K is sent through the throttle valve 7 to the phase separator 8, from where the gas phase is sent to the first mixer 22 for mixing with the X ₂ stream and further cooling of the stream (1 -X ₁ -X ₂ ) and flow (1-X ₁ ), and the liquid phase is sent for storage in a cryogenic tank 9.

A device for implementing the claimed method by compressing purified air up to 50 atm. includes (Fig. 3) node 1 for air purification from mechanical impurities and purification from water (drying) by known methods, node 2 for CO ₂ removal by known methods, K ₁ ... K _N - compressor stages 3 for compressing the purified air to the optimum pressure for the selected cycle liquefaction (preferably 50 atm), TO ₁ ... TO _N - heat exchangers 4 for cooling compressed air or heat extraction and transfer to the heat storage, N - number of compressor stages 3 (preferably N=2..4, the compression ratio is determined as the final pressure compression ratio (1/N), where N is the number of compression stages), flow divider 16, heat exchangers 17 and 27, three-way heat exchanger 5 for cooling flow X ₁ with an auxiliary mixture cycle, mixture compressor 24, throttle valve 26, mixer 23, throttle valve 7, phase separator 8, cryogenic tank 9, cryogenic liquid air pump 10, heat exchanger 11 (or a group of successive heat exchangers) cold pumps 6 into the liquefaction cycle, recuperator 12 of the exhaust heat of the last stage of the turboexpander 13, heat supply system (external or heat accumulated from the compression stage) 14, heat exchangers 15 for heating the air before its expansion in the stages of the turboexpander 13 using the heat supply system 14, TD ₁ ... TD _M are the stages of the turboexpander 13, where M is the number of expansion stages (preferably M=2..4, the expansion ratio is defined as the initial expansion pressure in the degree of (1/M)).

This liquefaction cycle embodiment requires a preferred secondary mixture cycle composition of 32% methane, 15% ethane, 15% propane, 21% I-pentane, 17% nitrogen, and a preferred flow ratio X ₁ :(1-X ₁ ) about 0.5:0.5 of the flow rate entering the divider.

The liquefaction of air (charging) in the specified device is carried out as follows. Preliminary cleaning of atmospheric air is carried out, at least from mechanical impurities, water and carbon dioxide, compression is carried out (the degree of compression is defined as the final compression pressure in the degree (1 / N), where N is the number of compression stages) in one or more stages to pressure optimal for the selected liquefaction cycle (preferably up to 50 atm in stages 1-4) with cooling or heat extraction to the heat accumulator at the outlet of each compression stage, then after compression and cooling to a temperature close to the ambient temperature, the air is sent to the divider flow 16, where (1-X ₁ ) from the initial flow rate is transferred to cooling with cold accumulated at the generation stage, and X ₁ (the preferred ratio of costs X ₁ :(1-X ₁ ) is about 0.5:0.5 from the input flow divider) is transferred to indirect cooling by an auxiliary closed mixture circuit (the preferred composition of the mixture includes 32% - methane, 15% - ethane, 15% - propane, 21% - I-pentane, 17% - nitrogen). In the mixture circuit, the mixture is compressed by compressor 24, followed by cooling in heat exchanger 25 to ambient temperature, then the cooled mixture is sent to a three-way heat exchanger 5, then it is cooled to about 100 K by the reverse flow of the mixture, the mixture is sent through the throttle valve 26 again to the three-way heat exchanger 5, where the direct flow of the mixture and the air flow X ₁ are cooled by the reverse flow of the mixture, the mixture is returned to compression to repeat the mixed auxiliary cycle, then the two flows (1-X ₁ ) and X ₁ are mixed after cooling in the mixer 23, the total cooled compressed flow (with temperature of about 100 K) through the throttle valve 7 is sent to phase separation in the phase separator 8, from where the gas phase is sent to the atmosphere after additional cooling (heat removal) of the air flow (1-X ₁ ) indirectly through the coolant circuit in the heat exchanger 27, and the liquid fraction sent to the storage stage in a cryogenic tank 9, stage

The system of accumulation and transfer of cold, which can be used in any of the variants of the claimed device, is shown in Fig. 3. The system contains warm and cold methanol tanks (ТТМ and ХТМ) 28 and 29, warm and cold propane tanks (ТТП and ХТП) 30 and 31, heat exchangers 17 for indirect supply of cold to the liquefaction cycle by pumping from cold tank 29, 31 to warm methanol and propane 28, 30, respectively, heat exchangers 11 for indirect cold extraction from liquid air supplied to the generation by pumping propane and methanol from a warm tank to a cold one, respectively, pumping equipment for methanol and propane circuits is not shown in the diagrams for simplicity, ready-made purchased equipment is used low pressure (preferably up to 15 atm), located at the inlet and outlet of warm tanks to reduce the requirements for pumping equipment of the cold storage system.

At the time of generation, propane indirectly removes cold by pumping from a warm tank to a cold one, the methanol circuit follows the propane circuit along the path of compressed air, cold is taken off by methanol indirectly by pumping methanol from a warm tank to a cold one, at the end of generation, cold coolants are stored in cold tanks , at the time of charging the system, cold is supplied to the selected liquefaction cycle in the most optimal places of the circuit determined during optimization, propane transfers cold to air during liquefaction indirectly by pumping propane from a cold tank to a warm one, methanol transfers cold to air indirectly by pumping from a cold tank to a warm, the cycles of selection and transfer of cold are repeated throughout the entire operation of the system.

A heat storage and transfer system that can be used to store and transfer heat from compressors or external heat is shown in FIG. 4 and FIG. 5 and includes a hot coolant tank and a warm coolant tank (GTT and TTT) 32 and 33, as well as heat exchangers 4 for extracting heat from compressors (or third-party heat, for example, steam extraction from a nuclear power plant or thermal power plant or a heating circuit of a nuclear power plant or thermal power plant) TO and heat exchangers 15 supply thermal oil or molten _salts can be used as a coolant;

The heat storage and transfer system stores the heat of the compressors at the time of power consumption failure; for this, heat exchangers are installed after each compressor stage, connected by a heat carrier circuit to the heat storage. There can be several heat carriers and circuits (water, water-glycol solution, thermal oil, molten salts), selected for the corresponding temperature ranges.

The stored heat is used to increase the generation power by indirectly heating the air during generation before the expansion stages.

At the moment of generation, the coolant is pumped from hot tank 32 to warm tank 33, indirectly transferring heat to the working fluid (air) before the expansion stage, the number of heat accumulation circuits may differ from the number of heat transfer circuits before expansion, for example, if compression occurs in 2 stages, and generation in 4 steps, then there are 2 heat storage circuits, and 4 heat supply circuits from two tanks (Fig. 5), or, if heat is taken from a third-party source, then there can be 2 tanks with one heat extraction circuit, and heat supply circuits can be 4 by 4 expansion steps, but with 2 tanks.

The heat storage and transfer system can be connected to the steam or heating circuit of a nuclear power plant or thermal power plant or another, the heating circuit is preferable, since it does not require intervention in the operation of the turbine, to accumulate heat during the power consumption dip and use it at the peak at the generation stage to increase power. In this case, the use of compressor heat may be more expedient than steam heat extraction from a turbine or heating circuit, since it allows the use of heat with a temperature ^of 220-400 ° C and higher, depending on the number of compression stages.

On FIG. Figure 4 shows a diagram of a device in which liquefaction occurs at a pressure of up to 150 atm, with an increase in the generation power due to the supply of compression heat to the generation. The device includes a node 1 for air purification from mechanical impurities and water purification (drying) by known methods, a node 2 for removing CO ₂ by known methods, K ₁ ... K ₂ - compressor stages 3 for compressing the purified air to the optimum pressure for the selected liquefaction cycle (preferably 150 atm), compression heat accumulator 14, including GTT 32 and TTP 33, TO ₁ ... TO ₂ - heat exchangers 4 for heat extraction and transfer to GTT 32 of heat storage 14, three-way heat exchanger 5, where the flow is cooled to approximately 100 K by the reverse flow of the gas phase from the phase separator 8 and the cold accumulated at the generation stage in the cold storage and transfer system 6, the throttle valve 7, the phase separator 8, the three-way heat exchanger 5, the cryotank 9, into which the liquid phase is directed to the stage of storing liquid air (stored energy). At the right time (for example, during the peak period of energy consumption), liquid air is compressed by a cryogenic pump 10 (up to a pressure of 35-256 atm) and fed into the heat exchanger 11 (or a group of successive heat exchangers) to evaporate the air and heat it, as well as take cold from the accumulation system and cold transfer 6, then the air passes through the heat exchanger 12 for extracting exhaust heat from the last stage, then the heating heat exchanger 15 before the expansion stage TO _G1 and expands in the first stage of the turbo expander 13 TD ₁ , then passes M heaters 15 TO _GM and stages TD _M (preferably M =2…4, the degree of expansion is defined as the initial expansion pressure in the degree (1/M)), after leaving the last stage, it is sent to the heat exchanger 12 to transfer heat to the incoming flow and is released into the atmosphere in the form of environmentally friendly clean air, heat supply to heat exchangers TO _G is carried out by the system of accumulation and transfer of heat 14, described above.

On FIG. 5 shows a diagram of a device for implementing the claimed method, the operation and composition of which are described above in relation to FIG. 4, the difference lies in the number of expansion stages, and the diagram also shows how the accumulation of heat during compression in 2 stages allows the heat to be distributed between 4 stages when there is enough heat;

On FIG. 6 shows a diagram of a device for implementing the claimed method, in which liquefaction is carried out in the same cycle as in FIG. 4 and FIG. 5, but without the accumulation of heat of compression, while the increase in generation power is carried out by utilizing the heat of the gas turbine exhaust gas.

On FIG. 7 shows a diagram of a device for implementing the claimed method, in which liquefaction is carried out in the same way as in devices, the diagrams of which are presented in FIG. 4- Fig. 6, and generation is performed by a combination of a turboexpander 13 and a gas turbine plant 35, the fuel for which is supplied to the combustion chamber 34.

- for renewable energy sources, the method implemented according to the above procedure can be supplemented with stabilizers of the generated RES power, namely two low-capacity Li-Ion batteries to equalize the power supplied to the CVPS, operating alternately on the large-capacity CVPS, made according to the method described above,

- the time of charging and discharging in the method may differ, for example, according to the described method, charging can take 8 hours, and discharging for 3-4 hours, this allows you to reduce capital costs for the liquefaction system,

- in the method, generation can occur in two stages by a combination of a turboexpander with a gas turbine, with heating of the air in front of the turboexpander by the flue gas flow of the gas turbine before being released into the atmosphere, fuel supply at the outlet of the turboexpander before the gas turbine.

Confirmation of the possibility of implementing the proposed method and device, as well as achieving a technical result is the following examples (the efficiency of pumps, turbines and compressors is taken equal to 0.8).

Example. 1. The declared liquefaction cycles for CVNS with the supply of cold accumulated during generation have the following characteristics when compressed in 4 stages:

- liquefaction according to the first version of the cycle - 829 7 kW / (1 kg / s of the liquid phase), the liquid output coefficient is 0.8;

- liquefaction according to the second version of the cycle - 942.9 kW / (1 kg / s of the liquid phase), the liquid output coefficient is 0.56;

- liquefaction according to the third variant of the cycle (mixed) - 905.2 kW / (1 kg / s of the liquid phase), the liquid output coefficient is 0.84.

The declared cycles are close in terms of energy costs, differ in the level of compression pressure. The mixed cycle allows for a faster first start-up of the system, since due to it cold is always supplied to the cycle, incl. before the first start of generation.

Example. 2. An example of the application of the circuit shown in FIG. 5.

The overall efficiency of the system shown in Fig. 5, when compressed to 150 atm in 2 stages (stage 1 - from 1 to 12.2 atm5, stage 2 - from 12.25 to 150 atm) allows you to accumulate and transfer heat between 4 generation stages with expansion from a pressure of 125 atm (1 stage - from 125 atm to 37.38 atm, stage 2 - from 37.38 to 11.18 atm, stage 3 - from 11.18 to 3.34 atm, stage 4 - from 3.34 to 1 atm) with temperature 675 K in front of each stage. The efficiency of such SNES is more than 60%. The advantage of the system is that there is no need for additional fuel, the system belongs to RES, as it has zero emissions.

Example. 3. An example of the application of the circuit shown in FIG. 6 - utilization of heat of GTP.

Consider the scheme of the device for the implementation of the claimed method on the example of heat recovery of flue gases (76 kg/s of exhaust gas with a temperature of 461 ^about C) mobile GTES FT8® Mobilepac®. The flow rate of liquid air for generation of 20 kg/s makes it possible to obtain, in addition to the power generated by the mobile GTPP, about 12 MW, minus the operation of the cryogenic pump. The efficiency of the system (the ratio of the energy spent on liquefaction to the energy generated without taking into account the power generated by the GTP) is more than 70%; the efficiency, taking into account the power generated by the GTP, is about 200%. The ratio of generated power to gas consumption for FT8® Mobilepac® without CVPS is about 2.84 MW/(1m ³ /h of gas). The use of KSNE allows you to increase this figure to 4.36-4.86 MW / (1 m ³ / h of gas). Thus, the circuit shown in Fig. 6 makes it possible to obtain a new product for power control - a combination of GTP and CVPS, which, unlike GTP without CVPS, not only compensates for the power deficit during the peak period, but also equalizes the daily energy consumption schedule, i.e. allows you to accumulate energy in the hours of "failure".

Example. 4. An example of the application of the circuit shown in FIG. 7 - a combination of a turboexpander and a gas turbine at the stage of generation (discharging).

The generation receives 5.2 kg/s of liquid air. The consumption of natural gas in the combustion chamber is about 580 m ³ /h. The efficiency of such a system is about 115%. The total generation is about 5 MW minus the operation of the cryogenic pump. The generated power to the gas consumption is 8.5-8.96 kW/(1 m ³ /h of gas), which is significantly higher than peak gas turbines with a conventional cycle.

The claimed method and variants of the device for its implementation make it possible to create energy storage systems with the following advantages:

- high density of stored energy;

- compactness (the possibility of placement where necessary);

- a large amount of stored energy;

- large resource cycling;

- relatively low specific capital costs (stored energy and installed capacity);

- the possibility of scaling up to the needs of large energy;

- the possibility of using equipment mastered by the industry.

Claims (51)

1. A method of energy accumulation with the production of cryogenic liquids, energy storage and its release using various heat sources at the generation stage, including the steps at which: - atmospheric air is cleaned at least from mechanical impurities, water and carbon dioxide; - purified atmospheric air is compressed in one or more stages to a pressure that is optimal for the selected liquefaction cycle with a decrease in air temperature at the outlet of each compression stage to a temperature close to the ambient temperature; - compressed and cooled to a temperature close to ambient temperature, the air is cooled to approximately 100 K; - cooled to a temperature of approximately 100 K, compressed air under pressure through a throttle valve is fed into the phase separator for phase separation; - in the gas separator, the cooled air is separated into gas and liquid phases; - from the phase separator, the gas phase is sent to the atmosphere after cooling the input compressed air flow after the cooler of the last compression stage, and the liquid fraction is sent to the storage stage in a cryogenic tank; - the liquid fraction is stored in a cryogenic tank for the required period of time; - if there is a need for energy generation, the cryogenic liquid (liquid fraction of air) is compressed by a cryogenic pump to a pressure of 35 to 256 atm; - after which the compressed liquid air is passed through at least one first heat exchanger, when passing through which it is heated with the selection of cold into the cold storage system, then the air is passed through at least one second heat exchanger, where it is heated with the supply of heat taken from heat sources; - before expansion in turbo-expanders in one or several stages, if several stages are used, air is heated before each stage, while the exhaust from the last expansion stage using an additional heat exchanger is directed to heat the air flow entering the generation stage between the last heat exchanger of the cold storage system and before the first heat supply heat exchanger before expansion, after the transfer of heat to the inlet air flow, environmentally friendly exhaust in the form of gaseous air is released into the atmosphere. 2. The method according to p. 1, characterized in that the air temperature at the outlet of each compression stage is reduced by taking heat into the heat accumulator. 3. The method according to p. 1, characterized in that the purified air is compressed to 150 atm. 4. The method according to claim 1 or 3, characterized in that compressed and cooled to a temperature close to ambient temperature, the air is cooled to a temperature of approximately 100 K using the cold accumulated at the generation stage and the reverse flow of the gas phase from the phase separator . 5. The method according to p. 1, characterized in that the purified air is compressed to 70 atm. 6. The method according to claim 5, characterized in that the air cooled to a temperature close to the ambient temperature is sent to the flow divider, where part of the air (X ₁ ) from the initial flow rate is transferred to cooling with the cold accumulated at the generation stage, and the remaining part (1-X ₁ ) is transferred for cooling by the flow leaving the turboexpander and the gas phase of the separator, after which this part of the air (1-X ₁ ) from the initial flow rate is transferred for separation to the second flow divider, in which part of the incoming air ( X ₂ ) is sent for expansion in the turbo expander, then mixed at the outlet of the turbo expander with the gas stream from the phase separator, after which their mixture cools the stream (1-X ₁ -X ₂ ) leaving the second flow divider and entering the second stream mixer, which mixes the flows X ₁ and the flow (1-X ₁ -X ₂ ), from where the cooled compressed flow (1-X ₂ ) with a temperature of about 100 K is sent through the throttle to the phase separator. 7. The method according to p. 6, characterized in that the ratio of costs X ₁ :(1-X ₁ ) is about 0.6:0.4 of the incoming flow to the divider, and the ratio of costs X ₂ :(1-X ₁ - X ₂ ) is about 0.35:0.65 of the flow rate entering the divider (1-X ₁ ). 8. The method according to p. 1, characterized in that the purified air is compressed to 50 atm. 9. The method according to claim 8, characterized in that the air cooled to a temperature close to the ambient temperature is sent to the flow divider, where part of the air (1-X ₁ ) from the initial flow rate is transferred to cooling with cold accumulated at the generation stage, and part of the air X ₁ is transferred to indirect cooling by an auxiliary closed mixture circuit, including compression of the mixture, cooling to ambient temperature, cooling to about 100 K by the reverse flow of the mixture, expansion of the mixture through a throttle, cooling of the direct flow of the mixture by the return and air flow X ₁ , return mixtures for compression to repeat the mixed auxiliary cycle, then after cooling, two streams (1-X ₁ ) and X ₁ are mixed, the total cooled compressed stream with a temperature of about 100 K is sent through the throttle to the phase separator. 10. The method according to claim 9, characterized in that the ratio of costs X ₁ :(1-X ₁ ) is about 0.5:0.5 of the flow rate included in the divider. 11. The method according to claim 9, characterized in that the mixture in the mixture circuit has the following composition: 32% - methane, 15% - ethane, 15% - propane, 21% - I-pentane, 17% - nitrogen. 12. The method according to claim 1, characterized in that the time during which the energy is stored exceeds the time during which the stored energy is released. 13. The method according to claim 1, characterized in that the energy generation is carried out in two stages, while the air in front of the turboexpander is heated by the flue gas flow of the gas turbine plant before being released into the atmosphere, fuel is supplied at the outlet of the turboexpander before the gas turbine plant. 14. The method according to claim 1, characterized in that one of the following heat sources is used to heat the air before expansion at the generation stage: direct combustion of fuel in air in a turbine, waste heat from industrial enterprises, landfill gas combustion, exhaust gas from gas turbine plants, in including peak ones, steam extraction from NPP or TPP, heating circuit of NPP or TPP. 15. A device designed to implement the method according to claim 1 or 3, including an air purification unit from mechanical impurities and water purification, a CO ₂ removal unit, N compressor stages for compressing purified air, where N is equal to or more than 1, N heat exchangers, designed to cool compressed air, a three-way heat exchanger, a system for storing and transferring cold to a liquefaction cycle, a throttle valve, a phase separator, a cryogenic tank for storing energy in the periods between energy storage and its release at the generation stage, a liquid air cryogenic pump, at least one heat exchanger for evaporation and removal of cryogen cold into the cold storage system, exhaust heat recuperator of the last stage of the turboexpander, heat supply system, M heat exchangers for heating air before its expansion in the stages of the turboexpander using a heat supply system, M stages of the turboexpander, while the air purification unit is connected to CO ₂ removal node, node output removal of CO ₂ is connected to the inlet of the compressor, the outlet of which is connected to the inlet of the heat exchanger, the outlet of which is connected to the first inlet of the three-way heat exchanger, the second inlet of which is connected to the outlet of the cold accumulation and transfer system to the liquefaction cycle, and the third inlet is connected to the outlet of the phase separator, the inlet of which through a throttle valve it is connected to the first outlet of the three-way heat exchanger, the second outlet of which is connected to the inlet of the cold accumulation and transfer system to the liquefaction cycle, and the third outlet is designed to remove air from the cryoblock, the second outlet of the phase separator, designed to remove liquid air, is connected to the cryogenic tank , the outlet of which is connected through a cryogenic pump to a heat exchanger designed to evaporate and take cryogen cold into the cold storage system, the outlet of said heat exchanger is connected to the first inlet of the exhaust heat recuperator of the last stage of the turboexpander, the recuperator is connected in parallel to the heat supply system. 16. The device according to claim 15, characterized in that the compressor has N steps, where N=2, or N=3, or N=4. 17. The device according to claim 15, characterized in that the cryogenic tank is made with vacuum thermal insulation. 18. The device according to claim 15, characterized in that the turbo expander has M stages, where M=2, or M=3, or M=4. 19. The device according to claim. 15, characterized in that the device includes a group of sequential heat exchangers. 20. The device according to claim 15, characterized in that the system for accumulating and transferring cold contains warm and cold methanol tanks, warm and cold propane tanks, heat exchangers for indirectly supplying cold to the liquefaction cycle by pumping methanol and propane from the cold tank to the warm tank, respectively, heat exchangers and for indirect extraction of cold from liquid air supplied to the generation by pumping propane and methanol from a warm tank to a cold tank. 21. The device according to claim 15, characterized in that the heat storage and transfer system includes a hot coolant tank and a warm coolant tank, as well as heat exchangers for extracting heat from the compression process or from another external source and heat supply heat exchangers before expansion, while as The coolant uses water, or thermal oil, or molten salts, pumping equipment installed at the inlet to the warm coolant tank and at the outlet of the warm coolant tank to operate in the heat transfer and withdrawal cycle, respectively. 22. The device according to claim 15, characterized in that it additionally includes a stabilizer for power generated by external energy sources. 23. The device according to claim 22, characterized in that two low-capacity Li-Ion batteries are used as a stabilizer for the power generated by external energy sources. 24. A device designed to implement the method according to claim 1 or 6, including an air purification unit from mechanical impurities and water purification, a CO ₂ removal unit, N compressor stages for compressing purified air, N first heat exchangers designed for cooling compressed air, where N is equal to or greater than 1, a cold storage and transfer system, a phase separator, a turbo expander, a cryogenic tank for storing energy in the periods between energy accumulation and its release at the generation stage, the first flow divider, the second heat exchanger designed to cool the flow X ₁ using cold accumulated at the generation stage in the cold storage and transfer system, the third heat exchanger designed to cool the flow (1-X ₁ ) by the reverse flow of the gas phase from the phase separator and the flow after expansion, the second flow divider, the fourth heat exchanger designed to cool the flow ( 1-X ₁ -X ₂ ) by the reverse gas flow from the phase separator and p expansion outflow, the first gas flow mixer designed to mix flows from the phase separator and the turbo expander outlet X ₂ , the second mixer designed to mix flows X ₁ and (1-X ₁ -X ₂ ), a throttle designed to expand the cooled flow (1 -X ₂ ) phase separator, fifth heat exchanger designed for evaporation and withdrawal of cryogen cold into the cold storage system, exhaust heat recuperator of the last stage of the turboexpander, heat supply system, M heat exchangers for heating the air before its expansion in the turboexpander stages using the heat supply system, M stages of a turboexpander, wherein the outlet of the air purification unit from mechanical impurities and water is connected to the inlet of the CO ₂ removal unit, the outlet of which is connected to the inlet of the compressor for compressing the purified air, connected by the outlet to the inlet of the first heat exchanger, the outlet of the first heat exchanger is connected to the inlet of the first divider streams, the first output of which o is connected to the inlet of the second heat exchanger, the second outlet of the first flow divider is connected to the first inlet of the third heat exchanger, the first outlet of the third heat exchanger is connected to the inlet of the second flow divider, the first outlet of which is connected to the inlet of the turboexpander, the second outlet is designed to remove air from the cryoblock, the third outlet is connected with the first inlet of the fourth heat exchanger, the second inlet of which is connected to the outlet of the gas flow mixer from the phase separator and the outlet of the turbo expander X ₂ , the first inlet of the second mixer is connected to the outlet of the turbo expander, the second inlet of the second gas flow mixer is connected to the first outlet of the phase separator, the second outlet of the phase separator is connected to the inlet of the cryogenic tank, the inlet of the phase separator is connected through a throttle to the outlet of the first mixer, the first inlet of which is connected to the outlet of the second heat exchanger, and the second inlet is connected to the outlet of the fourth heat exchanger, a heat circuit is connected in parallel to the second heat exchanger carrier of the cold storage system, the outlet of the cryogenic tank through the cryogenic pump is connected to the fifth heat exchanger, the outlet of the fifth heat exchanger is connected to the first inlet of the exhaust heat recuperator of the last stage of the turboexpander, the recuperator is connected in parallel to the heat supply system. 25. The device according to claim 24, characterized in that the compressor has N steps, where N=2, or N=3, or N=4. 26. The device according to claim 24, characterized in that the cryogenic tank is made with vacuum thermal insulation. 27. The device according to claim 24, characterized in that the turboexpander has M stages, where M=2, or M=3, or M=4. 28. The device according to claim 24, characterized in that the device includes a group of sequential heat exchangers. 29. The device according to claim 24, characterized in that the system for the accumulation and transfer of cold contains warm and cold methanol tanks, warm and cold propane tanks, heat exchangers for indirectly supplying cold to the liquefaction cycle by pumping methanol and propane from the cold tank to the warm tank, respectively, heat exchangers and for indirect extraction of cold from liquid air supplied to the generation by pumping propane and methanol from a warm tank to a cold tank. 30. The device according to claim 24, characterized in that the heat storage and transfer system includes a hot coolant tank and a warm coolant tank, as well as heat exchangers for extracting heat from the compression process or from another external source and heat supply heat exchangers before expansion, while as The coolant uses water, or thermal oil, or molten salts, pumping equipment installed at the inlet to the warm coolant tank and at the outlet of the warm coolant tank to operate in the heat transfer and withdrawal cycle, respectively. 31. The device according to claim 24, characterized in that it additionally includes a stabilizer for power generated by external energy sources. 32. The device according to claim 31, characterized in that two low-capacity Li-Ion batteries are used as a stabilizer for the power generated by external energy sources. 33. A device designed to implement the method according to claim 1 or 9, including an air purification unit from mechanical impurities and water, a CO ₂ removal unit, at least one compressor stage for compressing the purified air, at least one first heat exchanger for cooling compressed air, the first flow divider, the second and third heat exchangers designed to cool the flow (1-X ₁ ) using the cold accumulated at the generation stage in the cold storage and transfer system, a three-way heat exchanger designed to cool the flow X ₁ with an auxiliary mixed cycle, a compressor designed to compress the mixture, a fourth heat exchanger designed to cool the mixture to ambient temperature, the first throttle valve, a mixer in which flows X ₁ and (1-X ₁ ), a second throttle valve, a phase separator, a cryogenic tank, a fourth heat exchanger, while the outlet of the air purification unit from mechanical impurities and from water is connected with the inlet of the CO ₂ removal unit, the outlet of which is connected to the inlet of a compressor designed to compress the purified air, the outlet of the specified compressor is connected to the inlet of the first heat exchanger, the outlet of which is connected to the inlet of the first flow divider, the first outlet of the first divider is connected to the first inlet of the second heat exchanger, the second the outlet of the first divider is connected to the first inlet of the three-way heat exchanger, the first outlet of which is connected to the first inlet of the mixer, the second outlet of the three-way heat exchanger is connected to the inlet of a compressor designed to compress the mixture, the outlet of which is connected through the fourth heat exchanger to the third inlet of the three-way heat exchanger, the third outlet of the three-way heat exchanger through the first throttle valve is connected to the second inlet of the three-way heat exchanger, the mixer outlet is connected through the second throttle valve to the phase separator, the first outlet of which is connected to the cryogenic tank inlet, the second outlet is connected to the first inlet of the fifth heat exchanger, the first outlet of the fourth heat exchanger is connected to the first inlet of the third heat exchanger, air is removed from the cryoblock through the second outlet of the fourth heat exchanger, the outlet of the cryogenic tank through the cryogenic pump is connected to the fifth heat exchanger, the outlet of the fifth heat exchanger is connected to the first inlet of the exhaust heat recuperator of the last stage of the turboexpander, the recuperator is parallel connected to the heat supply system. 34. The device according to claim 33, characterized in that the compressor has N steps, where N=2, or N=3, or N=4. 35. The device according to claim 33, characterized in that the cryogenic tank is made with vacuum thermal insulation. 36. The device according to claim 33, characterized in that the turboexpander has M stages, where M=2, or M=3, or M=4. 37. The device according to claim 33, characterized in that the device includes a group of sequential heat exchangers. 38. The device according to claim 33, characterized in that the system for the accumulation and transfer of cold contains warm and cold methanol tanks, warm and cold propane tanks, heat exchangers for indirectly supplying cold to the liquefaction cycle by pumping methanol and propane from the cold tank to the warm tank, respectively, heat exchangers and for indirect extraction of cold from liquid air supplied to the generation by pumping propane and methanol from a warm tank to a cold tank. 39. The device according to claim 33, characterized in that the heat storage and transfer system includes a hot coolant tank and a warm coolant tank, as well as heat exchangers for extracting heat from the compression process or from another external source and heat supply heat exchangers before expansion, while as The coolant uses water, or thermal oil, or molten salts, pumping equipment installed at the inlet to the warm coolant tank and at the outlet of the warm coolant tank to operate in the heat transfer and withdrawal cycle, respectively. 40. The device according to claim 33, characterized in that it additionally includes a stabilizer for power generated by external energy sources. 41. The device according to claim 40, characterized in that two low-capacity Li-Ion batteries are used as a stabilizer for the power generated by external energy sources.

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