JPH0786338B2 - Cogeneration system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cogeneration system that efficiently uses heat energy and electric power energy.

[Prior Art] A cogeneration system intends to efficiently use electric energy and thermal energy that change depending on time and season in a building, a factory, or the like.

In a conventional system, electric energy and thermal energy generated during system operation have a unique relationship, but they cannot be mutually converted.

In cogeneration systems, the objective of high efficiency utilization is achieved when the demand and supply of electricity and heat generated energy are balanced.

However, in actual use, supply and demand are rarely balanced, and energy cannot be converted into each other as described above, so that there are the following problems.

[Problems to be Solved by the Invention] That is, during electric power load following operation, if there is no use destination of the recovered thermal energy, part or all of it is released to the atmosphere.

Further, during the heat load following operation, surplus power was consumed by a dummy load or the like.

Further, since the prime mover is operated in accordance with either the electric power demand or the heat demand, the partial load operation is performed and the efficiency is reduced.

The present invention has been made in view of the above circumstances, and an object thereof is to enable mutual conversion between electric power energy and thermal energy, and to recycle and utilize exhaust heat energy generated by driving a generator. It is to provide a cogeneration system that improves operating efficiency by providing a utilization system.

[Means for Solving the Problems] The above object of the present invention is to recover surplus heat energy when the heat demand decreases and supply it to an electric boiler, and to generate electricity by the heat energy heated and pressurized by the electric boiler. In addition, when the power demand drops, surplus power energy is recovered to drive the electric boiler, and heat energy is obtained by the electric boiler, and exhaust heat energy after driving the generator is supplied to the heat load equipment and condensed. This is achieved by recirculating the condensed water obtained as above as cooling water.

[Operation] That is, by using the electric boiler, thermal energy is converted to electric power when the heat demand is low, and electric power energy is converted to heat when the electric power demand is low, thus driving the generator. From the perspective of the prime mover, the prime mover can be operated based on the total demand for electricity and heat,
Partial load operation is reduced and efficiency can be improved.

Further, the exhaust heat energy after driving the generator is supplied to the heat load equipment, and the condensed water obtained by condensing is used for cooling the prime mover. It can prevent the release into the inside.

[Embodiment] An embodiment of a cogeneration system to which the present invention is applied will be described below with reference to FIG.

FIG. 1 shows a basic circuit configuration diagram of a cogeneration system, which uses a power energy conversion system that converts heat energy into power energy, a heat energy conversion system that converts power energy into heat energy, and exhaust heat energy. The exhaust heat utilization system is composed of the following components.

In the drawings, the valve mechanism, the bypass pipe, the supply pipe, and the like provided according to the purpose of use are not shown.

First, the structure will be described. The prime mover 1 is composed of a diesel engine, a gas engine, a gas turbine, etc., and drives the generator 2. Reference numeral 3 is a cooling water heat exchanger, but the prime mover 1 is a gas turbine. If it becomes unnecessary. The exhaust gas heat exchanger 4 is for exchanging heat with respect to the exhaust gas of the prime mover 1, and the heat load device 5 is an absorption refrigerator,
Devices such as heat exchangers and hot water storage tanks are used according to the purpose.

The electric boiler 6 is for obtaining steam and high temperature water,
It may be integrated with the exhaust gas heat exchanger 4. A steam turbine 7 drives a generator 8. Further, 9 is a condensed water tank, and the condensed water tank 9 is for condensing the exhaust gas of the steam turbine 7 while passing through the heat load device 5, and for collecting and recirculating the condensed water having a predetermined temperature. When the steam turbine 7 is not used, the exhaust gas heat exchanger 4 and the electric boiler 6
The higher temperature heat energy gives heat energy to the heat load device 5, and as a result, it becomes hot water of a predetermined temperature and the condensed water tank 9
Leading to. In any of the above cases, it is essential that the temperature of the hot water in the condensed water tank is the temperature required for cooling the prime mover 1, and if there is no heat demand for the heat load equipment 5, the temperature is adjusted by the radiator 10 such as a cooling tower. It

The wiring a shown by a dotted line is for supplying electric power of the generator 2 to the electric boiler 6
For supplying power to b, and b indicates an exhaust gas pipe.

Next, the operation of the cogeneration system will be sequentially described.

 The effect when power and heat demands are balanced.

In this case, the same operation as in the conventional case is performed. That is, the generator 1 is driven by the prime mover 1, and all the electric power generated from the generator 2 is supplied to the required facilities. Further, after the heat energy recovered by the cooling water heat exchanger 3 and the exhaust gas heat exchanger 4 is supplied to each heat load device 5, the used hot water is passed through the condensed water tank 9 to the cooling water heat exchanger 3. Is recycled.

Action when power demand is low and heat demand is low.

In this case, the heat energy recovered by the cooling water heat exchanger 3 and the exhaust gas heat exchanger 4 is supplied to the electric boiler 6. Then, the heat of the electric boiler 6 is transferred to the steam turbine 7
The temperature is raised to the temperature and pressure required to drive
Electric power supplied from the generator 2 via the wiring a is used as the heat source.

Further, the steam turbine 7 is driven by the steam obtained from the electric boiler 6, and the generator 8 is further driven by the steam turbine 7 to supply electric power corresponding to the demand to each facility. In addition, when the required steam is obtained from the exhaust gas of the prime mover 1 by the exhaust heat gas heat exchanger 4, the same operation can be obtained without using the electric boiler 6.

The steam discharged from the steam turbine 7 is condensed by the heat load exchangers 5 and the radiator 10 to a temperature required for cooling the prime mover 1, and then supplied to the cooling water heat exchanger 3.

Action when there is heat demand and power demand is decreasing.

In this case, the surplus portion of the electric power generated by the generator 2 is supplied to the electric boiler 6 via the wiring a, and the electric boiler 6 can generate hot water or steam depending on the purpose of the heat load device 5. The electric boiler 6 can also raise or / and raise the heat energy recovered by the cooling water heat exchanger 3 and the exhaust gas heat exchanger 4, if necessary.

The heat energy obtained in the electric boiler 6 is supplied to the heat load device 5 and is passed through the condensed water tank 9 to the cooling water heat exchanger 3
And / or is circulated to the exhaust gas heat exchanger 4. While circulating as described above, the required power is covered by the total generated power, and the surplus power is heat-exchanged to use 100% of the power.

As described above, according to the cogeneration system shown in the present embodiment, since the energy conversion from electric power to heat and heat to electric power is performed, it is possible to flexibly perform the energy supply according to the momentary demand change. Become.

In addition, the demand for electric power and thermal energy fluctuates depending on the time of the day and the season, but since all generated energy can be used, overall efficiency is improved, and energy is supplied according to the type and amount of energy required by the demand side. Will be possible.
Moreover, since the partial load operation of the prime mover 1 is improved, the operation can be performed with high efficiency and energy saving can be obtained.

Further, since the high temperature exhaust gas generated from the prime mover 1 is always used, the high temperature exhaust gas is not released into the atmosphere, and an excellent effect can be obtained in terms of pollution prevention.

[Effects of the Invention] As described above, the cogeneration system according to the present invention uses two types of energy by a conversion system that converts heat energy into electric power energy and a conversion system that converts electric power energy into heat energy. It is configured so that mutual conversion can be performed.

Therefore, energy conversion can be performed according to the needs of the energy demand side, and efficient use of electric power and thermal energy can be achieved.

Moreover, since the system can be operated based on the total energy demand, the partial load operation of the prime mover can be reduced.

Further, since the cogeneration system of the present invention has an exhaust heat utilization system that condenses exhaust heat energy through a heat load device and recycles condensed water obtained by condensing, the thermal energy is effective. Can be used for In addition, the exhaust heat utilization system having the above-mentioned configuration does not require this condenser by placing the function of a condenser for condensing and recirculating water in the corresponding conventional configuration in the heat load equipment, thereby reducing the entire system. Can be built at cost.

[Brief description of drawings]

FIG. 1 is a basic configuration of a cogeneration system showing an embodiment of the present invention. (Symbols in the figure) 1: prime mover 2,8: generator, 3: cooling water heat exchanger, 4: exhaust gas heat exchanger, 5: heat load equipment, 6: electric boiler, 7: steam turbine, 9: condensed water tank , 10: radiator, a: wiring, b: exhaust gas pipe

Claims (1)

[Claims] 1. Electric power energy conversion for recovering surplus thermal energy to supply to an electric boiler when the heat demand decreases, and driving a generator by the heat energy heated and pressurized by the electric boiler to convert it into electric energy. System, a thermal energy conversion system that recovers excess electric energy when the electric power demand decreases and supplies it to the electric boiler, and obtains thermal energy that is heated and pressurized by the electric boiler, and exhaust heat energy after driving the generator. A cogeneration system that includes a waste heat utilization system that supplies heat to a heat load device to condense it.