JPH0354325A - Surplus power utilizing system - Google Patents

Abstract

PURPOSE:To improve efficiency by connecting a heat exchanger, which is for utilizing heat exchanged with low temperature air after it is expanded, to an expander and positively collecting even energy generated following a volumetric change of air. CONSTITUTION:Air is compressed by compressors 2A, 2B with surplus power at nighttime or the like, and a temperature of cooling water from a hot water device 5 is increased by heat exchangers 3A, 3B with the air of increased temperature, thereafter the air is cooled and accumulated in an air storage tank 4. Next at daytime with a large demand of power, the air storage tank 4 is connected to an expander 6A by selecting a pipe line, here the compressed air is expanded to drive the expander 6A, and power is generated by a generator 7. After a temperature of the air, expanded in the expander 6A, is decreased, by a heat exchange with a refrigerant in a secondary side by a condenser 8A, the air, with the temperature again increased, is fed to an expander 6B here further expanded, and power is generated by driving the expander 6B. The temperature of the air is again decreased by expansion, and the refrigerant is cooled also in a condenser 8B. The air, output from the expander 6B, is provided with a low pressure and a low temperature approximate to the normal temperature and used as a room-cooling load 9.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a surplus power utilization system.

[Background Art] While the power supply capacity of power plants is improving, the difference in power demand between daytime and nighttime is increasing. Therefore, if surplus power at night is stored in some form and supplied during the day, the power supply capacity does not have to be so large, and that capacity can be fully utilized.

Therefore, several measures have been proposed or implemented in order to store the above-mentioned nighttime power. For example, a system is known in which compressed air is produced using the surplus power and stored to prepare for regeneration during the day, as shown in FIG. 2 of the accompanying drawings. In FIG. 2, an electric motor 5l drives a compressor @52 in response to surplus power at night, etc., and compressed air is stored in an air storage tank 53. The compressed air in the air storage tank 53 is taken out during the daytime when power consumption is high and guided to the combustor 54, and the combustion gas obtained here drives a gas turbine 55, and a generator 56 generates electric power. . In this way, surplus electricity during the night is used during the day.

[Problem to be solved by the invention]

However, in the conventional method described above, the energy of surplus electricity stored as compressed air is only used for combustion gas to drive the gas turbine, and temperature changes due to air compression and expansion are avoided. Energy was not being utilized and was not efficient.

An object of the present invention is to provide an extremely efficient system for utilizing surplus power by actively recovering the energy generated due to changes in the volume of air.

[Means for Solving the Problems] According to the present invention, the above objects include: a compressor driven by an electric motor; an air storage tank for storing compressed air compressed by the compressor; In an expander that operates by receiving compressed air and a generator driven by the expander, the expander is connected to a heat exchanger for utilizing cold energy that exchanges heat with the expanded low-temperature air. It is achieved by being.

(Function) In the present invention, compressed air is stored in an air storage tank by operating a compressor using surplus electricity at night. During the day when electricity demand is high, compressed air is taken out from the air storage tank and used in an expander. The compressed air rotates and drives the generator attached to the expander to generate electricity.Furthermore, after the compressed air operates the expander,
It expands, cools down, and is guided to a heat exchanger, where its cold energy is recovered.

〔Example〕

Embodiments of the present invention will be described below based on FIG. 1 of the accompanying drawings.

In FIG. 1, reference numeral 1 denotes an electric motor connected to a common shaft of the first-stage compressor 2A and second-stage compressor 2B to rotationally drive the two compressors. The outlet side of the first stage compression i2A is connected to the inlet side of the second stage compressor 2B via the primary side (solid line side) of the intercooler 3A which is a heat exchanger.
The outlet side of is connected to the air storage tank 4 via the primary side of the aftercooler 3B.
It is connected to the. Cooling water from the water heater 5 as a load is introduced into the secondary side (dotted line side) of each of the intercooler 3A and aftercooler 3B, and returns as hot water through heat exchange with high-temperature compressed air. ing. In addition, in the present invention, the intercooler 3A and the aftercooler 3B are shown as a preferable form and are not essential, and the first stage compressor 2A and the second stage compressor 2B are directly connected, and the second stage compressor 2B is The compressed air that exits may be directly introduced into the air storage tank 4.

The air storage tank 4 is connected to the first stage expander 6A by switching the pipe line.
It is designed to be connected to. A second stage expander 6B is directly connected to the output shaft of the first stage expander 6A, and a generator 7 is connected to this. The outlet side of the first stage expander 6A that receives compressed air from the air storage tank 4 is connected to the inlet side of the second stage expander 6B via the primary side of the first condenser 8A. The primary side of the second condenser 8B is connected to the outlet side of the condenser 8B, and a cooling load 9 such as an air curtain is connected to this. An evaporator 11 having a refrigeration load 10 is connected to the secondary side of each of the first condenser 8^ and the second condenser 8B. In addition, in this embodiment, as a preferable form, the evaporator 11 is connected to the two condensers 8A and 8B.
It is also connected to the air storage tank 4 by a parallel pipe line to the pipe line.

In the device of this embodiment as described above, surplus power at night is utilized in the following manner.

(1) First, the first stage compressor 2A and the second stage compressor 2B are driven by the electric motor 1 which is rotated by surplus electric power at night or the like. The air taken in by the first stage compressor 2A is compressed here. The compressed air has already risen in temperature, and is cooled by heat exchange in the ink cooler 3A, that is, by raising the temperature of the cooling water from the water heater 5, and enters the second stage compressor 2B. In the second stage compressor 2B, the compressed air is further compressed and the temperature rises again along with the compression.

Then, the heated compressed air is cooled in the aftercooler 3B after raising the temperature of the cooling water from the water heater 5 by heat exchange, and then is stored in the air storage tank 4.

■Next, during the daytime when the demand for electricity is high, the air storage tank 4 is connected to the first stage expander 6A by switching the pipe line, and the compressed air is expanded there. is driven, and the generator 7 generates electricity. After the temperature of the air expanded in the first stage expander 6A is lowered, the air is heated again by exchanging heat with the secondary refrigerant in the first condenser 8A, and then sent to the second stage expander 6B. The second stage expander 6B further expands to drive the second stage expander 6B and generate electricity. and,
The temperature of the refrigerant decreases again due to expansion, and the refrigerant is also cooled in the second condenser 8B. In this way, when the air exits the second stage expander 6B, it becomes low pressure and low temperature close to room temperature, and is used as a cooling load 9 such as an air curtain.

■ In the first condenser 8A and the second condenser 8B, the temperature of the compressed air in the air storage tank 4 decreases due to expansion, so its temperature becomes low, and the refrigerant that exchanges heat with it also becomes low temperature, so its cooling energy is It is used for the refrigeration load 10 via the evaporator 11.

(2) When the compressed air in the air storage tank 4 gradually decreases due to use, the pressure becomes low and the temperature drops, so at that time the refrigerant is guided to the pipe inside the air storage tank and its cold energy is utilized.

[Effects of the Invention] As described above, the present invention stores compressed air using surplus power, drives an expander, generates electricity with a generator connected to the expander, and generates heat and cold during expansion. Since it was decided to also utilize the energy, the energy recovery efficiency is greatly improved. Furthermore, if the heat generated during the production of compressed air is also utilized, the efficiency will be even higher.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional example. 1・・・・・・・・・・・・・Electric motor 2A, 2B・
......Compressor 3A, 3B...Heat exchanger (3A...Intara, 3B...Aftercooler) 4...
・・・・・・・・・Air storage tank 6A, 6B・・・・・・・
・・Expansion machine 7・・・・・・・・・・・・・・Start @machine 8A, 8B・
...Heat exchanger (8A...first condenser,
8B...Second condenser) Agent for Nippon Steel Tube Co., Ltd.

Claims (2)

[Claims] (1) A compressor driven by an electric motor, an air storage tank that stores compressed air compressed by the compressor, an expander that operates by receiving compressed air from the air storage tank, and a compressor driven by the expander. 1. A system for utilizing surplus power, characterized in that the expander is connected to a heat exchanger for utilizing cold energy that exchanges heat with low-temperature air after expansion. (2) According to claim (1), a heat exchanger for heat utilization that exchanges heat with high-temperature air after being compressed by the compressor is connected between the compressor and the air storage tank. surplus electricity utilization system.