JPS62138656A - Cold and hot energy storage system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The disclosed technology belongs to a technical field in which energy is stored during off-peak usage of energy such as electric power for consumer use and industrial use, and is used when necessary. .

This invention utilizes a compression heat pump cycle that follows the processes of polytropic compression, cooling, liquefaction, expansion, and endothermic gasification of fluids such as ammonia gas and carbon dioxide. This invention relates to a storage system, and in particular,
During off-peak electrical energy use, surplus energy from equipment compared to peak times is converted into low-pressure gas such as ammonia gas, raised to high pressure by a compressor, etc., and then used as cold energy from practically unmanned stores such as seawater. The high-pressure liquefied gas is cooled and liquefied using the Joule-Thomson effect, and stored as a high-pressure liquefied gas during peak energy use. The cold energy generated in this process can be used in a freezer or the like to recover energy, or in combination with the Rankine cycle, it can be used as a cold energy source for the cooling liquefaction process of the Rankine cycle, and the cold energy can be The energy is released and the gasified fluid is absorbed or adsorbed onto a gas absorption medium such as an ammonia gas complex to reduce the capacity and stored, and again absorbed from the gas absorption medium into this at the off-peak time. Alternatively, the invention relates to a system in which the adsorbed gas is separated at low pressure, fed again to the above-mentioned compressor, etc., and compressed again to high pressure and repeated.

[Prior art]

As is well known, the use of energy is essential for both civil and industrial activities, but in any case, the demand for energy such as electricity and fuel gas is not constant over time, and major fluctuations are due to seasonal factors. Small fluctuations include peaks and off-peaks due to time factors such as day and night.

However, as a matter of course, on the energy supply side, equipment planning is based on demand during peak periods, so it is necessary to reduce the load during off-peak periods,
Although we are trying to balance the supply by suspending operations, it is inevitable that the operating efficiency of the equipment will be poor, and the energy efficiency of the equipment will deteriorate during low-load operation, and furthermore, it will inevitably lead to poor investment efficiency. This is a prerequisite.

Such a decline in operation during off-peak hours is extremely negative from the perspective of social capital, and is also extremely unignorable from the perspective of energy economics.

To deal with this, an energy storage system is proposed that stores surplus energy during off-peak periods by operating equipment in the same way or similar to that during off-peak periods, and then extracts and uses it as desired during peak periods. It has started to be researched and developed.

[Problem that the invention seeks to solve]

For example, a pumping dam uses surplus electricity to pump water up to a dam at night, or a large underground tank is used to compress air by sending it to a surplus expansion turbine at night, which can be used during peak hours during the day. Research is underway into systems that generate electricity using compressed air, systems that use the flywheel's inertia to keep the seven-wheeler rotating with surplus electricity, and energy storage systems that use superconductivity.

Of these, pumped storage dams and pneumatic power storage have been put into practical use, but only the pumped storage dam method has been commercialized, and the flywheel method and superconducting method are still at the research stage and are unlikely to be put into practical use in the future. is a considerable investment over time, and 2
A research period of about 0 years is required, and actual development may not be completed in time.

However, both in pumped storage dams and compressed air energy storage, there are problems caused by locational conditions.
Moreover, the efficiency is also inferior.

[Purpose of the invention]

The purpose of the present invention is to alleviate the low-load operation during off-peak hours of the energy supply facility based on the above-mentioned conventional technology, and to aim at average capacity operation of the energy supply facility, by storing surplus energy during off-peak hours, The efficiency is such that a large amount of cold energy can be recovered and used during peak hours, and the efficiency is such that a large amount of cold energy can be recovered and used compared to the energy used during off-peak hours. It is possible to recover rotational energy with higher efficiency than other water pumps, etc., and in addition, since it requires small-scale equipment, there are almost no restrictions on plant location, and it can be performed at low cost. The object of the present invention is to provide an immersed cold energy storage system which will be able to take full advantage of the state of the art technology and which will benefit economic applications in the energy industry.

[Means/effects for solving the problem] In accordance with the above-mentioned object, the structure of the present invention, which is summarized in the claims described above, is designed to solve the above-mentioned problem. Sometimes it is a compression type, which compresses the low-pressure gas such as ammonia gas used in the pump cycle by inputting surplus energy during off-peak times to the motor of a compressor such as a compressor. After raising the temperature of the high-temperature and high-pressure gas to high temperature and high pressure, the temperature of the high-temperature and high-pressure gas is cooled and liquefied using practically unlimited available seawater or the cold energy released from LNG, and stored as high-pressure liquefied gas in high-pressure tanks, etc., and the energy demand side At its peak, the high-temperature, high-pressure liquefied gas is converted into a low-temperature, low-pressure liquid and gas through an expansion valve or the like by the Joule-Thomson effect, and the cooling energy during the transition from the low-temperature, low-pressure liquid gas state to the low-pressure gas is transferred to a freezer, etc. The energy stored in the high-pressure liquefied gas is effectively utilized by utilizing it in an external facility, and the fluid gasified by increasing the enthalpy in the process is heated and pressurized by pressure and temperature manipulation to produce an ammonia complex. A refrigerant such as seawater or air is used to absorb heat in a gas absorbing medium such as seawater or the atmosphere, and the volume that has once increased through gasification is reduced before being stored. During off-peak periods, the gas that has absorbed ammonia gas, etc. The medium is brought to a low-temperature, low-pressure state using an expansion valve, and then seawater, air, solar heat, and industrial waste heat are used.

The ammonia gas etc. that had been absorbed by heating with steam etc. is efficiently separated and taken out, and this is led to the above-mentioned compressor etc., and the pressure is raised again to high crystallization, thereby following the compression type, -1, and pump cycle. It takes technical measures to effectively reuse energy stored during off-peak times during peak times.

[Example - Configuration]

Next, embodiments of the present invention will be described below with reference to the drawings.

In the embodiment shown in FIGS. 1 and 2, A is a cold energy storage system that is the gist of the present invention, and as shown in FIG. 1, it is closed by a piping system, and the closed system is as shown in FIG. The horizontal axis enthalpy l shown in
Well-known compression heat pump cycle with vertical axis pressure P (A)
, (b), (c), (d).

(The working fluid is made to follow the ladle, and the work!l1
The gas of the lJ fluid is ammonia (
As mentioned above, for example, during off-peak energy such as electric power, ammonia gas (0 is The surplus energy during off-peak hours is input through a predetermined cleaner 1, and the compressor 2 operates to compress and pressurize the gas to a high temperature and raise the temperature, resulting in a high-temperature, high-pressure gas (b).

At this time, the ammonia gas supplied to the Congo tank 2 is at a temperature of, for example, 10°C and a pressure of 1 kg/cot.
It is a G gas, and when it is heated to high temperature and pressure by the compressor 2, it is a gas at a temperature of over 150° C. and a pressure of 15 kg/cmG.

In this embodiment, the compressor 2 is shown in one stage, but due to the design depending on the conditions, for example, the compressor 2
If the output pressure is low in one stage, an appropriate means such as an intercooler or pre-cooler may be used (7) to pass through a double membrane compressor.

The high-temperature, high-pressure ammonia gas thus obtained is then cooled and liquefied in a condenser (heat exchanger) 3 using seawater, the atmosphere, etc., which can be used virtually without limit.

The temperature of the gas liquefied by cooling by the condenser 3 is 35° C., and the pressure is 15 kg/cn? It is night (ha) of G.

The ammonia gas thus liquefied at high pressure is stored in a storage tank 4 in a high-pressure storage manner.

Therefore, in this embodiment, since the energy storage mode in the storage tank 4 is room temperature and high pressure storage as described above, stable storage over time can be performed without being affected by time, 2 days, 2 months, 2 years, etc. However, depending on the type of fluid, there are modes of high-temperature, high-pressure storage, or low-quality, high-pressure storage, which requires a high-pressure tank with specified insulation. Of course, the storage is done during off-peak hours.

During peak power usage, the liquefied ammonia gas stored in the storage tank 4 is inflated with Ple via the expansion valve 5, and the liquid at low temperature and low pressure or the mixed phase of liquid and gas is used. It becomes ammonia gas (d), and the cold energy until the entire amount of the low-temperature, low-pressure liquid or liquid and gas is vaporized is supplied to the cold heat recovery and utilization device 6,
In the cold energy recovery and utilization device 6, for example, the surplus energy during off-peak hours stored in the storage tank 4 is effectively used for the first time by exchanging heat with the working fluid gas of a freezer or the like to supply cold energy to the freezer or the like. , Therefore, as a result, effective [4] utilization of surplus energy input is performed.

The ammonia gas (d), which has been reduced in temperature and pressure by the expansion valve 5, has a temperature of -9°C and a pressure of 2 kg/. The ammonia gas (the temperature is raised to 0°C to 10°C, and the pressure is 2 kg/cTjG, which is low-pressure ammonia gas) that supplied cold energy in the cold energy recovery and utilization device 6. In terms of Enkurubi, the cold energy at temperatures ranging from -9°C to 0°C to 10°C, which corresponds to the amount of change in Enkurubi from (d) to (e) in Figure 2, was recovered by being effectively used in freezers, etc. It turns out.

As mentioned above, the cold energy recovered by the cold heat recovery and utilization device 6 can be used directly in a freezer or the like, or it can be put into the low-temperature side of a thermoelectric power generation element and taken out in the form of energy such as electricity or work as appropriate. It is possible.

Therefore, the liquefied ammonia gas stored in the storage tank 4 as an energy storage mode returns to a low-pressure gas body of 0°C to 10°C after passing through the cold heat recovery and utilization equipment 6, and is therefore in a liquefied state. If the volume of ammonia gas in the gasified state is the ammonia of the example, 3
00 to 400 times, making it unsuitable for handling as a working fluid.

Therefore, in order to deal with this, in the present invention, the low-pressure ammonia gas (ladle) from the cold heat recovery and utilization equipment 6 is absorbed into a gas absorption medium and liquefied, thereby reducing its volume and making it possible to store it. It is being done.

That is, -m is ammonia gas for ammonia as a gas absorption medium for the gaseous fluid in the gasified state;
-7'' For lopane, butane, freon, carbon dioxide, etc., there are liquid or slurry forms such as water-based gas absorption media (hydrates, hydroxides) and potassium carbonate.

The above-mentioned low-pressure ammonia gas (ladle) is supplied to the gas absorption tank 7 containing the gas absorption medium, and to the gas absorption tank 7,
Liquid ammonia complex (
Gas absorption media such as ammonium thiocyanate) are pressurized by pressure and temperature manipulation.

The crystallized liquid is fed into the absorption tank 7 so that low-pressure ammonia is absorbed in the shower of the gas absorption medium.

The liquid ammonia complex absorbs low-pressure ammonia gas and becomes a liquid state while dissipating heat to a cold heat source at a constant temperature and constant pressure. The target cooling source can be something with a relatively high temperature (such as seawater or air).Also, since the pressure is increased in advance by pressure manipulation, the amount of ammonia gas absorbed is greater than in the case of low pressure. Therefore, a relatively small amount of liquid ammonia complex gas absorption medium can absorb and liquefy a predetermined amount of low-pressure ammonia gas (e).At this time, the pressure levels of the low-pressure ammonia gas (e) and the liquid ammonia complex are harmonized. Therefore, a compressor 2a is installed between the cold heat recovery and utilization device 6 and the gas absorption tank 7.
may be interposed.

Therefore, the ammonia gas whose volume has been reduced by being absorbed by the gas absorption medium in the gas absorption tank 7 has been changed into a form that is advantageous for storage and pipe transportation.

The ammonia gas absorbed by the gas absorption medium in the gas absorption tank 7 is sent to the heat exchanger 16 via the pump 8, and is sent to the gas absorption tank 7 from the gas absorption medium storage facility Wi13 as described later. The gas absorbing medium exchanges heat with the gas absorbing medium to raise its temperature, is cooled down, and is then sent to the gas absorbing medium storage facility 9 to be stored as a storage body in preparation for the next off-peak period.

In this way, from the state in which the surplus energy stored in advance is recovered as cold energy during peak power usage, when power usage shifts to the next off-peak, the gas that has absorbed the ammonia stored in the gas absorption medium storage equipment 9 The absorption medium is appropriately supplied to the gas release tank 11 using a pump or the like, but at this time, the pressure is reduced to a low level by the expansion valve 10 before the gas release tank 11, and a part of the ammonia gas that has been absorbed is released. The temperature is lowered, and the lowered gas absorption medium is heated by an external heat source inside the gas absorption tank 11 to release ammonia gas (a).

Since the gas absorption medium is previously lowered to a lower temperature by the pressure operation by the expansion valve 11, the external heat source for heating may be a relatively low temperature one, such as inexpensive seawater or the atmosphere.

There is a wider range of options to choose from, including solar heat and factory waste heat.

The generated ammonia gas (A) passes through the splash cleaner 1 and is again supplied to the compressor 2, forming a compression heat pump cycle (A) as shown in FIG.

(σ), (c), (d)i#).

The gas absorption medium such as ammonia complex separated in the gas release tank 11 is stored in the absorption medium storage facility 13 after gas separation via the pump 12, and is used for cold heat recovery during the next power peak. However, during the next cold recovery, the gas absorption medium is pressurized to a predetermined pressure using the pump 14, and is supplied to the heat exchanger 1G as a temperature control, heated to a predetermined temperature, and then transferred to the gas absorption tank 7. Feed again in the form of a shower, and as mentioned above, low pressure ammonia gas (N)
absorb.

In this case, instead of providing the heat exchanger 16, a heat exchange tube is built into either the gas absorption medium storage equipment 9 or 13, and the gas absorption medium on either the outbound or return trip and the gas absorption Heat exchange with a medium may also be performed.

Regarding the heating equipment for the gas discharge tank 11 (by connecting it with the endothermic device of the gas absorption tank 7 through the piping 15, the energy used in the equipment can be made more economical by performing some reforming and offsetting the heating equipment). Therefore, in the above-described embodiment, the operating rate of the power plant (not shown), etc. can be uniformly and effectively operated in terms of total energy.

In the above embodiment, in order to reduce the volume of the low-pressure ammonia gas from the cold heat recovery and utilization device 6, a liquefied ammonia complex is used as a gas absorption medium, and this is stored in a pressurized state in the gas absorption medium storage facility 9. As shown in FIG. The function of the medium storage facility 13 may also be used.

As shown in FIGS. 1 and 3, a heat exchanger 16a using seawater or atmospheric air is further installed between the heat exchanger 16 and the gas absorption tank 7, and the gas showered in the gas absorption tank 7 is The absorption medium may also be heated. In addition, a compressor 2a is disposed in the pipe line between the cold heat recovery and utilization device 6 and the gas absorption tank 7, as shown by the imaginary line, and compresses the low pressure ammonia gas from the cold heat recovery and utilization device 6. It is also possible to feed the gas into the gas absorption tank 7 in a compressed volume in order to improve the efficiency of absorption into the gas absorption medium.

Furthermore, as the working fluid in the compression heat pump cycle, not only the ammonia gas used in the above-mentioned embodiments but also various fluids such as envy gas and propane gas can be used.

Furthermore, the system of the present invention does not necessarily need to be installed at an energy supply facility, but may be installed in a distributed manner at an energy consuming facility.

Next, the embodiment shown in FIGS. 4 and 5 will be described. In the embodiment shown in FIGS. 1 and 3 above, in the gas absorption tank 7,
In the middle of the line in which the gas absorption medium that has absorbed the gas that has passed through the cold heat recovery and utilization device 6 is fed and stored by the pump 8 to the gas absorption medium storage facility 9, the gas absorption medium and the gas absorption medium are transferred from the absorption medium storage facility 13 to the gas absorption tank. 7 is provided with a heat exchanger 16 for exchanging heat with the gas absorption medium fed to the gas absorbing medium 7. In the embodiment shown in FIGS. 4 and 5, this heat exchanger 1
Seawater, air, or A heat exchanger 17 using a heat medium existing around the equipment is provided, and the gas absorption medium from the gas absorption tank 7 to the gas absorption medium storage film WI9 can be cooled, that is, stored in a high pressure state without decreasing the temperature. Depending on the cooling design, a heat exchanger 18 may be provided in the line from the gas absorption tank 7 to the gas absorption medium storage facility 9, and the other configurations are the same as those in the first and second sections. Since this embodiment is similar to the embodiment shown in FIG. 3, detailed explanation will be omitted.

〔Effect of the invention〕

As described above, according to the configuration of the present invention, the following effects can be obtained.

(a) Basically, the operation of equipment, whether for civil or industrial use, involves load fluctuations during peak and off-peak times, but energy use is required in energy supply facilities such as power plants that must constantly supply energy. In order to cope with the peak load of workers, their operating capacity is designed for peak hours, resulting in lower operating rates during off-peak hours and significant waste. In contrast, in the system according to the present invention (7), surplus energy is supplied to the fluid flowing through the compression heat pump cycle during off-peak hours to perform an energy storage system, and this is recovered and effectively used as cold energy during peak hours. Regardless of where the system is installed, it will be possible to contribute to the leveling of power demand, etc.

(b) The gas whose cold energy is recovered and used by the cold energy recovery and utilization device is efficiently absorbed by the gas absorption medium whose pressure and temperature are raised in the gas absorption tank, and is also absorbed by easily available refrigerants such as seawater and the atmosphere. ) There is an economic advantage to storing essentially gaseous fluids in a liquid state in small volumes.

(e) The low-temperature, high-pressure gas absorption medium that has absorbed the gas is expanded and sent to the gas release tank via the expansion valve during off-peak hours, so the gas absorption medium in the gas release tank is easily The gas is effectively heated by a heat medium such as seawater or the atmosphere that is available in the world, and the gas absorbed by the gas absorption medium is easily released using an inexpensive heat medium, resulting in great economic effects.

[Brief explanation of drawings]

Fig. 1 is a schematic system diagram of the embodiment, Fig. 2 is a graph of the compression type beat pump cycle, Fig. 3 is a schematic system diagram from the embodiment shown in Fig. 1 with the gas absorption medium storage equipment omitted, and Fig. 4 is a schematic diagram of the embodiment. Another schematic system diagram on the actual flow side, FIG. 5, is a schematic system diagram in which the gas absorption medium storage equipment is omitted from the embodiment shown in FIG. 4. Capacitor, 4. Storage tank, 5. Expansion valve, 6.
Cold heat recovery and utilization equipment, 7. Gas absorption tank. 8-pump, 9-gas absorption medium storage equipment, 10-expansion valve, II-gas release tank, 12-pump, 13-absorption medium storage equipment, 14-boosting pump, Hi, 10a
, 17 Heat exchanger.

Claims (1)

[Claims] (a) In an energy storage system utilizing a compression heat pump cycle, (b) Using rotational energy obtained from off-peak surplus electricity, low-pressure gas is compressed to produce gas at high temperature and high pressure. (c) At peak times, the low-temperature, high-pressure liquefied gas is reduced to low temperature and pressure through an expansion valve, and the resulting cold energy is utilized. Energy is recovered, and (d) the gas whose enthalpy has been increased by recovering and using the cold energy is transferred to a gas absorbing medium (chemical heat storage material, etc.) whose temperature and pressure have been increased by pressure and temperature manipulation, and is then transferred to easily available sources such as seawater and air. After removing and absorbing heat with a refrigerant, this gas absorption medium is stored in a high pressure state, and (e) during off-peak hours, the high pressure gas absorption medium is passed through an expansion valve to a gas discharger in a low temperature and low pressure state. The absorbing gas is heated in the gas emitting device by an easily available heating medium such as seawater, the atmosphere, or solar heat, and the absorbed gas is released, and this low-pressure gas is compressed and pressurized again.The cycle is repeated. A cold energy storage system featuring: