Plan for scientific research

Subdivision: energy storage using compressed air.

Alexandr Novykh, Ph.D. 2016

Table of contents Cogeneration and trigeneration installations. .............................................................................................. 2

Application of energy storage using a compressed air. ................................................................................ 5

Detailed analysis of the cogeneration plant with energy storage using compressed air. ............................ 8

Technical implementation of cogeneration units with compressed air drives. .......................................... 10

Option №1. The easiest. ......................................................................................................................... 10

Option №2: A more sophisticated and more effective. .......................................................................... 11

Option №3: Using compressed air drives a part of gas turbines. ........................................................... 12

Option №4. Solar power. ........................................................................................................................ 14

Collaboration compressed air storage with solar power plants and wind turbines. .............................. 15

Autonomous private solar power for a small home. .................................................................................. 17

Domestic storage of compressed air. .......................................................................................................... 19

Use of liquefied air. ..................................................................................................................................... 21

Cogeneration and trigeneration installations.

The main objective of the proposed research - improvement of existing cogeneration and trigeneration

plants, the development of new models.

Today, in the world it is widely used various designs of cogeneration and trigeneration plants. These

installations provide maximum fuel efficiency in the production of electricity and heat.

Two years ago, we designed and built a stand-alone installation of power generating electric power

5500 kW, which includes the following components:

• Six gas-piston cogeneration plants (CHP) power of 1063 kW each, equipped with heat recovery

units with capacity 1208 kW each;

• Two gas hot water boiler unit rated capacity of 4,250 kW;

• Two absorption chillers with total cooling capacity of 4000 kW complete with wet cooling

towers in the amount of 2 pieces with total capacity of 9362 kW of heat.

This is a classic trigeneration plant for the total energy supply companies. In addition to the enterprise

power plant provides heating of industrial premises in the winter and cooling in the summer air. Initial

fuel is used as efficiently as possible. The efficiency of the trigeneration installation reaches 90%. The

remaining 10% - this is the loss of low-grade heat that is removed from the room ventilation system.

The system operates autonomously, without resetting the surplus electricity to the network. Often reset

electric power surpluses to the network is not beneficial to the manufacturer, as energy networks

charge for this extra cost, or purchase electricity at a lower price. As a result, it only leads to additional

losses. That is why the installation is equipped with 6 gas engines. Stop one or more of the engines

produced in the case of reducing electricity consumption. However, in this case there is a simultaneous

decrease in the production of heat and cooling. Lack of thermal energy in this case is compensated for

by the gas boiler.

Electricity Boiler

Heat

Exchange

r

Heat

Exchange

r

It would seem that this is an ideal setting in terms of maximum utilization of the source of fuel, and

economic indicators. However, as shown by the results of operation of the installation during the year

the balance of electric and thermal loads are not always the same.

At the same electrical load in the winter is not significantly enough thermal capacity, and in the fall and

spring of thermal energy surplus, and it is discharged into the atmosphere. During the summer months a

small shortage of thermal energy to the refrigeration unit. The lack is compensated by the thermal

energy by burning additional fuel in boilers. Standing no balance, which ultimately results in lower

overall efficiency.

In addition, during the working day as the electrical load changes. Almost zero at night and up to a

maximum at the end of the working day.

Reduced electrical load is provided by disabling one or more engines. However, in proportion to the

reduction in electrical load is reduced and the production of heat that has to compensate for the

increase in productivity of auxiliary boilers. As a result, it reduced the effect of the entire installation.

Today imbalance of electrical and thermal load is achieved in the following ways:

1. By way of transition to clock mode (three shifts). Then, the electrical load is leveled during the

day. However, it is not always possible and economically profitable. For example, a large

supermarket can not work around the clock, it makes no sense. Besides, for night work, as a

rule, you need to pay more, and so on.

2. Increased power generators up to a maximum level of thermal load and discharge of surplus

electricity to the network. It is also associated with certain problems. As already noted, the

discharge of electricity in the network is not always beneficial for various reasons. Furthermore,

during the night and with excess electricity network. Energy companies are selling night

electricity at reduced rates, and it is not profitable to buy extra energy at this time.

3. Conversion of redundant electrical energy into heat via electric heaters. Of course, in this case,

we have some losses, but in the end we do not lose anything. Just all the fuel consumed for heat

production. In any case, are reduced by an additional boiler equipment costs.

4. The use of electric and thermal batteries that during the failure of a load store energy and

consume them during peak times. This is the most promising path, which allows you to

significantly increase the efficiency of cogeneration and trigeneration plants. It is possible to use

powerful batteries and thereby reduce electric power in the night can be similarly applied

centrifugal kinetic energy of the batteries and so on. All this is to smooth out fluctuations in the

loads throughout the day and will increase the efficiency of trigeneration installation as a whole.

The last line of perfection trigeneration plants most promising. Currently, electric load leveling of

electric power to the various devices used for the storage of the day. These devices include:

• pumped storage power plants;

• The batteries of electric accumulators;

• Kinetic storage of electrical energy;

• Supercapacitors and so on.

All these devices can successfully compensate for fluctuations in the electrical load on the network, but

fuel efficiency remains unchanged and amounts to not more than 45%. Only cogeneration and

trigeneration installations can increase fuel efficiency by at least twice.

In this connection, it is proposed to equip the trigeneration installation fourth elements - air

compressors.

Application of energy storage using a compressed air.

Let us return to the schedule of daily load.

As has been previously noted, the electric load varies during the day, and the thermal load remains

stable. Heat generation cogeneration plant repeats the schedule of electric load. Because of this, at

night we have a lack of heat, and in the period of peak demand in the electric network - the excess. In

principle, this is a small problem. Simple thermal energy storage to smooth these fluctuations. However,

it all depends on the size of the average heat load during the day.

If the average daily heat load is approximately equal to the average electrical loads, the total fuel

utilization factor will be the maximum and not less than 90%.

If the average daily heat load is significantly smaller (Min) average electrical loads, the total fuel

utilization factor drops to 45%.

If the average daily load of thermal energy much more (Max) average electrical load, it would take an

additional fuel consumption and total fuel utilization rate is approximately 60-70%.

In this connection, it is proposed to equip the trigeneration installation fourth elements - air

compressors.

The load of heat and electricity.

time of day

The production and

consumption of electrical energy.

Production of thermal

energy.

Consumption of thermal

energy

In this case, the engine running at a constant load throughout the day. The surplus electric power (with

load failure in the electrical network) is reset to an air compressor. Thus the heat generation is increased

by 60-70% due to the heating of air in the compression process. At the time of shortage of electricity the

compressor is stopped and made to develop more electric power due to the expansion of air. Thus, due

to exhaust gas produced extra heating the compressed air, which increases its potential energy.

As a result, we have the following advantages:

• The cogeneration unit is operating at the rated load continuously, without hesitation, that

allows you to achieve maximum efficiency.

• Maximum engine power can be reduced to the average load on the network. This helps reduce

the maximum engine power is at least 30%, which in turn will significantly reduce the cost of the

equipment as a whole.

• Heat production is also increased, thereby providing consumers with thermal energy in the cold.

• If the thermal energy needs not, compressed air can be performed by isothermal cycle. This will

reduce the costs for compression of air by about 40%. Before expansion the air can be heated by

exhaust gases to a temperature of 300-350 ° C, which will provide more electrical energy than

the compression of air to spent.

At present, much attention is paid to the development of various energy storage devices. The reasons

are three:

a. In many countries, the cost of the "night" of electric power is 2-3 times lower than the "day." If

you accumulate energy at night, and then use it during the day, the total costs will be

significantly lower.

b. The stored energy can be used at night to pay off peak day. This will allow to reduce to 30-40%

of the rated power of the power equipment that will eventually lead to a decrease in the cost of

equipment.

Energy load

Time

The electrical load on the network Generation of electricity Heat generation

c. A powerful impetus to the development of energy storage devices due to the development of

alternative energy. Solar and wind energy is variable and depends on the weather conditions.

This feature requires the use of various energy storage devices.

To date, various energy storage devices, namely, various batteries, kinetic drives, devices for

compressed air, pumped storage station and so on.

The graph shows that the best characteristics have pumped storage station. However, they have

one major drawback. For the accumulation of water energy necessary to the floor high enough and

it needs to build a fairly expensive construction. Application of this method is only useful when there

is natural elevations (mountains). On flat terrain to create such a structure is difficult.

Energy storage installations much easier and

more convenient. They can create any size

and placed anywhere. In addition,

compressed air batteries are both

trigeneration plants. The compressed air can

be converted into electrical energy, heat and

cold.

The world practice has already been several

attempts to create powerful energy storage

devices based on compressed air. The

simplest example - is the compressed air in underground storage preservation.

The main drawback of such designs is only one - a very low efficiency, not more than 50%). In the

compression process is a simultaneous increase in its temperature. Hot compressed air is difficult to

maintain, it will inevitably give the excess heat to the environment. In making the air have to be

heated to the initial temperature of the electric energy again, and this extra fuel consumption.

To avoid such a disadvantage can be in two ways:

a. It is useful to use the heat that is released during the air compression. In this case, we

get a double positive effect. First, it reduces the cost of compressed air by bringing to an

isothermal compression process. Second, the need to provide heat without additional

fuel costs.

b. Use the secondary air heating cheap thermal energy, which is available in abundance.

For example, you can use the free energy from the sun, to dispose of the heat of the

engine exhaust gases to recycle heat condenser chiller and so on. Use any source of

heat waste.

Using compressed air as an energy storage device can significantly improve the efficiency of

cogeneration and trigeneration plants.

Detailed analysis of the cogeneration plant with energy storage using compressed

air.

Compressed air may be performed in various ways. In theory, there are three basic processes of gas

compression: adiabatic, isothermal and polytropic. One or the other process is implemented

through a variety of technical devices. For example, isothermal gas compression process is

implemented by applying a multi-stage compressor with intermediate cooling gas after each stage.

The more compressor stages, the closer the compression process is isothermal cycle.

The graph shows that the best performance can be achieved by isothermal compression of air. In

this case, the cost of compressed air are minimal. If the air compression heat of exhaust gases of

internal combustion engine to 350 ° C temperature, during the expansion of the air in the expander

can be returned to 1.5-2 times more electric energy than is spent on compression of the air.

Calculations with respect to a specific cogeneration plant, which was considered by us in the

beginning.

During normal operation, this cogeneration plant provides a daily production of 66,160 kWh of

electricity and 113,417 kWh of thermal energy. At the same time, part of the power plant consists of

6 diesel generator power 1063 kW each. At minimum load (at night), the engine operates at only

one power level of 50-70%. With a maximum load of all engines running.

We add to this cogeneration plant compressor. Any excess electrical power is used to compress air

to a pressure of 5 to 10 bar, which will accumulate in the tank. At the time of peak load at the

beginning of the compressed air engine exhaust is preheated to 350 ° C, and then expanded in an

expander to produce additional electrical energy.

The calculations show that to fully ensure the same daily output of just two engines, which during

the day at a constant nominal mode. In the case of the isothermal compression to a pressure of 5

bar was required engine power 2235 kW, and in the case of polytropic compression of air to a

pressure of 10 bar - required power was 2450 kW. Moreover, the total daily fuel consumption

decreased by 12-17%. Fuel economy in the development of 66160 kWh of electricity was from 1700

to 2700 kg. The lower value of performance corresponds to the process of polytropic compression

up to 10 bar, and the top - isothermal compression process to a pressure of 5 bar.

For the first 9 hours of the compressors to fully charge storage of compressed air, and in the future

is its discharge in the next 13 hours. Then drive again been charged for another 2 hours.

As a result of the preliminary studies, the following conclusions:

1. The use of cogeneration units in the composition of compressed air energy storage enables a 2

times to reduce the mounting power of the main engines. As a result, this significantly reduces

the cost of battery power equipment.

2. Main engines work during the day at a constant nominal operation, which ultimately leads to

fuel savings.

3. The presence of excess thermal energy makes it possible to further heat the compressed air,

allowing you to provide additional production of electricity without fuel costs. This eventually

leads to a reduction in specific fuel consumption by 10-15%.

4. In comparison with other battery electric power, compressed air makes it possible not only to

return the stored energy without loss, but also to produce an additional 1.5-2 times more

elektoenergii.

5. The compressed air drives only have one big drawback - the large size. As the calculations above

cogeneration plant, compressed air drive must be designed for a capacity of at least 1000 - 5000

m3. To reduce storage volume of pressurized air needed to raise the pressure to 200 bar.

However, at such a pressure and exhaust gas temperature limitation positive effect can be

achieved only by isothermal compression of air.

Technical implementation of cogeneration units with compressed air drives.

Most of today's internal combustion engines are equipped with high-power air pressurization systems.

This allows not only to increase engine power,

but also improve its effectiveness. Recently,

internal combustion engines are equipped with

two-stage turbocharging systems. It uses both

turbochargers with exhaust energy of the

engine and supercharger driven by the engine

shaft. Much less frequently used Blowers

Power.

The two-stage system of an internal

combustion engine turbocharging works as

follows. Air from the atmosphere is sucked

through the primary air blower, which is driven by the motor shaft. Air is first compressed and injected

into the intercooler (Intercooler 1), where it is cooled after the first compression stage. Further, air flows

into the secondary turbocharger, which already uses the engine exhaust energy. The air is further

compressed and fed to the engine cylinders again through the air cooler (Intercooler 2). Power primary

blower drive shaft of the motor is sufficiently high and is 10-15% of the engine power.

Option №1. The easiest.

If the performance of the primary compressor to increase by 2-3 times, its capacity will increase to at

least 30-40% of the engine power. Excess compressed air will accumulate in the tank. During the period

of peak demand, drive the primary compressor is switched off, and a useful capacity of the engine is

increased by 30-40% and higher.

The proposed modernization of Standard engine boost circuit

In this embodiment, we do not change any parameters of the engine. The advantage of only one engine

is constantly working on the nominal mode. It occurs redistribution of load between the power of the

compressor and the power generator. However, the effect of fuel economy is. If, for example, take

specific Caterpillar 3516 engine, its specific fuel consumption at 50% load is 0.234 l / kWh, and with a

load of 100% - 0.21 l / kWh. Thus, ensuring stable operation of the engine at nominal conditions, we

provide savings 0,024 l / kWh or 38.4 l / h. Let this small, but still savings. In addition, providing a peak

shaving, we can reduce by 30-40% the mounting power of the main engines, which will have a very

substantial saving of initial construction costs of battery power. This variant does not differ from the

case with the installation of electrical batteries. The effect is almost the same. Only the energy storage

device design is much simpler and cheaper.

Option №2: A more sophisticated and more effective.

Internal combustion engine exhaust gas temperature at the outlet of tsilintrov is about 700 ° C. This is a

fairly high potential, which is partially used in the turbocharger to compress the air. However, the

output of the turbine drive exhaust gas temperature remains high enough to at least 450 ° C. To use this

potential in some installations use heat recovery boilers, which provide steam turbine generators. The

effectiveness of this steam cycle does not exceed 10-15% of the very low steam parameters. At the

same time, this option is very complicated power plant as a whole. In addition, such a structure does not

eliminate the problem of electrical load fluctuations. By reducing the engine power output also reduces

the steam cycle automatically.

The proposed modernization of Standard engine boost circuit

The proposed second embodiment does not have these disadvantages. The primary pre-compresses air

blower and pumps it into the first receiver (R1) of low pressure. The auxiliary booster compressor

pumps air into the receiver (R2) high pressure. The receiver R2 air is further heated by the heat of

exhaust gases. At the time of the peak blowers driven by the motor shaft disconnected. Heated

compressed air as the load is applied to growth D1 expander where expansion occurs with generation of

additional electricity. The air in the expansion process in the expander automatically lowers its

temperature and its parameters become suitable for the supply to the engine cylinders. Turbocharger

currently can also be disabled, allowing further heat the compressed air in the receiver R2 to 600 ° C. If

the air in the R2 receiver is not heated, but on the contrary, allow to cool to a temperature of at least

100-200 ° C, after the expansion of the air expansion turbine we get quite a lot of cold with

temperatures below -20 ° C.

The proposed design greatly simplifies the configuration of the trigeneration plant. We can exclude from

the HRSG equipment to remove heat from the exhaust gases, absorption chillers and so on. As a result,

this will lead to a significant reduction in price of trigeneration plants, increase their efficiency and

provide a stable load.

Option №3: Using compressed air drives a part of gas turbines. From the outset, the compressed air drives planned to use in conjunction with gas turbines. This is

significantly easier. As part of a gas turbine plant has a compressor, a turbine is (expansion turbine).

However, gas turbine units at a far inferior to the internal combustion engine performance. In addition,

with an increase in ambient temperature above 15 ° C, the efficiency of the gas turbine units plummets.

At the same time, even in this case, the use of compressed air storage is feasible. If you add a tank of

compressed air and pass through the exhaust duct from the heat exchanger can be abandoned. As a

R1

R2

~

result, the pressure loss will be reduced in the recuperator, and increase the degree of heating the air

from the exhaust gases, although the overall size of the installation, of course, will increase.

Compressor capacity gas-turbine plant is at least 30% of the power turbine. Consequently, the presence

of compressed air to allow the battery to increase by 30-40% useful power unit during peak power grid

by switching off the compressor. The turbine will be for some time to use a supply of compressed air in

the drive.

The above embodiments of cogeneration plants have economic viability. Some projects have already

been implemented. However, interest in the drives with compressed air in recent years has increased

briskly in connection with the rapid development of alternative energy.

Option №4. Solar power. Most countries are now actively developing solar power plants. At the same time, in recent years the

cost of solar photovoltaic panels has dropped considerably, which contributes to their further rapid

development. However, experts predict the emergence of additional load fluctuations in the power

network in connection with the development of solar energy.

Completely abandon the traditional sources of electrical energy, we can not. Solar power can not yet

fully provide us with electrical energy during the day. At the same time, a large number of decentralized

solar power plants. In the daytime, in the presence of intense solar radiation load of the electrical

network begins to fall, as electricity consumers tend to use more energy to local solar power. This

creates a big problem for traditional power plants and electrical networks, as after 16:00 begins a sharp

rise in the load. 2-3 hours load increases by 2 times. This sharp increase in load creates a big enough

problem for large power plants. Especially because after 21:00 slump begins again. The situation is

further complicated by the fact that the intensity of sunlight varies with the weather. Such load failures

have no strict regularity in time.

In this situation, the development and application of energy storage is particularly important. Of course,

the problem can be solved quite easily with the help of pumped storage power plants. However, such

structures are large enough and not everywhere can be constructed. This requires a fairly large

differences in elevation between the upper and lower reservoirs. Electric batteries as long as have

enough low density energy storage.

The ideal characteristics for the solution of these problems have a compressed air storage. They have a

relatively simple design and very high energy storage density. In addition, in contrast to all other energy

storage, compressed air can not only save electricity, but also get a discharge at 2 times more electricity

than is spent on compressed air. It has been shown previously. No other type of energy storage does not

allow it. It should also be noted that the compressed air drives quite easily scaled. Because you can

make big enough for large power plants, and small enough for private households. Duration of energy

storage in storage of compressed air is virtually unlimited.

Collaboration compressed air storage with solar power plants and wind turbines.

Currently, the most promising are hybrid power plant, which include solar photovoltaic installation and

natural gas-fired generators. This is the perfect option. On the one hand photovoltaic panels provide

maximum use of solar energy and natural gas-fired generators - provide supply security and stability.

The overall energy efficiency is quite high.

However, the sun does not only electricity but also heat. Consequently, the use of heat engine exhaust

gases is problematic. Sun provides enough heat energy that can be accumulated in a tank and used

within one day. Thermal energy is the engine, most likely in these conditions will not be in demand. If

applied as part of such a compressed air drive power, the efficiency of the entire power plant to

increase significantly, especially if the air by isothermal compression exercise cycle. During the daylight

hours of the electric power of photovoltaic panels will be used to compress the air. The compression

process can be a multi-step, to as close as possible to isothermal process. solar power Dimensions quite

possible to place multi-stage compressor. By the end of daylight compressed air accumulator is fully

charged. At night, when the gas-fired engines are started, exhaust gases are used to heat the air to a

temperature of at least 400 ° C. In the process of expansion of the air with these parameters in the

expander we can return in 2 times more electricity than spent on compressed air. If we compress 1 kg /

s of air up to 20 bar on the isothermal cycle, the total capacity of the multi-stage compressor will be 255

kW. If air is then heated to 400 ° C and apply to the expander, the output we will obtain 455 kW. The

temperature at the outlet from the expander Boden 135 ° C. Therefore, we still get an additional 135 kW

of heat energy. Thus, only through the use of compressed air storage can increase the efficiency of the

hybrid power twice.

To store a large amount of compressed gas tanks may be used, made of pipes of large diameter. These

pipes are used for the construction of gas pipelines. Compressors can also use the standard, and they

can be placed directly under the solar panels.

For example, we can make the payment in Spain newly built hybrid power plant.

The structure of the power plant includes: G52-850 kW wind turbine, photovoltaic panels 816 (245 kW)

and three diesel generator at 222 kW each. In the worst case (in the absence of sun and wind), this

power could provide maximum power 666 kW of electrical energy and about 800 kw of thermal energy.

In the presence of wind and solar total electric power can reach 900 kW to 1700 kW. According to

author of the project according to a similar power station is designed for power supply of about 400

families.

We make payment conditional two cases (excluding wind turbine)

1. Diesel generators work permanently and partially disabled when a solar energy. In this case, for

ease of calculation bude assume that solar power is working on a rated load of not more than 6

hours.

2. Diesel generators work permanently and partially disabled at work expander, and solar power

only works on compressed air, which is then heated by the exhaust gases of engines up to 400 °

C and is expanded in an expander. In the period of work

Again, for ease of calculation, we assume that the share of diesel generators consumption is 0.2 kg /

kWh.

During continuous operation, the total amount of diesel power generators will be 15,984 kWh of

electricity and about 19 MWh of thermal energy per day, and solar power will provide 6 hours 1470

kWh per day. Thus, the proper day for diesel generators in the first embodiment will ensure production

14,514 kWh of electric energy spent on this, and 2,903 kilograms of fuel. There will also be further

produced 17 MWh of thermal energy.

In the second case, the actual diesel generators will provide only 13 254 kWh of electricity and spend it

on 2650 kilograms of fuel. The amount of thermal energy is lower. Procedure 2.5 MWh of thermal

energy will be spent on heating the air, but 810 kWh of thermal energy will be returned at the exit of the

expander. As a result, the total amount of heat energy will be approximately 14-15 MWh.

Thus, at the same constant load 666 kW fuel economy in the second embodiment will be 253 kg per day.

If we discard the solar component of the project the total cost of fuel diesel engines would have

amounted to 3197 kilograms. Consequently, the solar component of the project to improve the

efficiency in comparison with the clean diesel option on 10%, and the addition of further compressed air

storage - 17%.

By increasing the capacity of solar power, efficiency will also increase. To heat the air up to 400 ° C

required heating capacity of 400 kW. Consequently, the electric power of such motor will be about 250

kW. If solar power capacity will be approximately equal to the diesel generator power, the efficiency of

the compressed air storage will be 50%.

Autonomous private solar power for a small home. Consider a small solar power station with capacity of 10 kW. To ensure the reliability of power supply

applies a gas piston generator 5 kW. Thus, solar power is only drive the compressor for compressing air.

Over 6 hours of intense solar radiation compression compressor 650 kg of air up to a pressure of 50 bar.

In this case the compressed air receiver will have a volume of less than 12 m3. When expanding gas,

preheated to a certain temperature, we can return the lost energy by using an expander. At the same

time, energy consumption will strictly correspond to the load. Air heating can be done with solar heaters

or exhaust gas-piston engine backup. Even if the cylinder or compressed air receiver would just stand in

the sun, its temperature can reach 100 ° C under certain conditions. If we add a small solar heater solar

energy concentrator, it is possible to achieve heating to 200-250 ° C. To heat the air to a higher

temperature external heat source required. For example, long-term absence of solar energy (a few

days), we will have to start the standby generator gas piston. Exhaust heat can be accumulated in a

special thermal accumulator. In the future, this heat can be used to heat the air. In the case huduschem

possible to use a small amount of fuel for heating the air.

The graph shows that the best performance can be achieved with all air compressed to 10 bar. Even

then we heat the air up to 250 ° C, then we can get 1.5 times more electricity than the cost of

compressed air.

For long-term storage of compressed air should use the standard compressor systems and storage of

compressed air.

0

0,2

0,4

0,6

0,8

1

1,2

1,4

1,6

1,8

2

0 100 200 300 400 500

The

rat

io

Air temperature before expansion, ° C.

The power ratio of the expander to the compressor capacity depending upon the temperature and pressure of compression air heating before expansion at a

constant rate.

10 bar

50 bar

100 bar

150 bar

For small off-grid solar power stations can apply simplified versions of the compressed air storage.

The last option is an autonomous solar power plant includes 40 photovoltaic panels with a total capacity

of 10 kW, autonomous gasoline generator 5 kW, multi-stage compressor, air-cooled, compressed air

drive 30 to 60 m3 (one module of the 4 pipes - 7 5 m3) and a turbine generator.

Domestic storage of compressed air. In a domestic environment, various electric heaters are used quite often. Always thought that the use of

electricity to generate heat energy is the most expensive way. However, recently, electricity is often

used for heating, water heating and cooking. It is particularly interesting that the solar PV panels began

to be used to generate heat energy. This is primarily due to the fall in prices for photovoltaic panels and

ease of installation of the equipment.

However, the direct conversion of electrical energy into heat energy is not quite economical. There are

many ways to more effectively generate thermal energy from electricity. The most simple and very

effective way is to use a heat pump. Using the electrical energy to drive the heat pump compressor, we

can get 3-5 times more heat energy than by direct heating with an electric heater. Such systems are

widely used for heating and hot water supply systems of buildings. However, in warm climates need for

a large amount of thermal energy available. But even in these conditions, use the direct electrical

heating is inefficient.

All hot water systems use hydraulic accumulators, which

are designed to maintain a certain pressure in the hot water

system. If the file from the compressor hot compressed air,

the water warms up in the hydraulic accumulator. At least

75% of the electrical power of the compressor is converted

into thermal energy. Even if the air in the system with cool

water, then at least 50% of the electric energy expended on

compressing the air can be returned. If the water then

warmed from an external source, it is possible to ensure the

return of all spent electricity.

For ease of operation make better use of the water turbine

to generate electricity. The compressor compresses air and

supplies it to the accumulator. Low water and compressed air in the accumulator is leveled. If you have

an electric energy needs of water from the accumulator via a hydraulic turbine generator enters the

feed tank. This produces an electric current, and the hot water from the supply tank is spent on

household needs.

Compressor | hydraulic accumulator |hydraulic turbine generator | expansion tank vortex tube

For 1 kWh of electric energy required to produce 1.8 m3 of pumping water at a pressure of 20 bar in the

accumulator, and at a pressure of 200 bar - total 180 liters of water, which corresponds approximately

to the daily consumption of water for 1 family. In addition, if the top of the accumulator installed vortex

tube, we can obtain the expansion of the air hot and cold energy source.

Of course, the compressed air has a lot of advantages, but its storage requires very large amounts of

storage tanks. With increasing pressure to the level of 100-200 bar tanks sizes are significantly reduced,

but at the same time increased requirements for tanks for the storage of security.

Use of liquefied air. Much more promising is the use of liquefied air. liquefied air density 800 times smaller than the gas at

atmospheric pressure. Liquefied air may be continuously kept at a slight excess pressure inside the

vessel. It is only necessary to eliminate the supply of heat from outside. The technology of liquefied air

or any other atmospheric gases is well established and does not cause any difficulties. Of course, in the

air enters the liquid oxygen, which can cause some difficulty because of its high concentration and

evaporation. To be safe, you can use liquid nitrogen, which is an absolutely inert gas and its share in the

composition of the atmospheric air is almost 80%.