JP6559596B2 - Digestion gas power generation system - Google Patents

Description

  The present embodiment relates to a digestion gas power generation system for a sewage treatment plant.

  In the sewage treatment plant, digestion gas generated from the digester tank of the sludge treatment facility is used as auxiliary fuel for heating the digester tank and sludge incineration. In recent years, introduction of a digestion gas power generation system that generates power by supplying digestion gas to a digestion gas power generation apparatus has been developed from the viewpoint of energy saving.

  In conventional digestion gas power generation systems, the number of digestion gas power generation devices is controlled while supplying the digestion gas to the digestion gas power generation device and controlling the number of digestion gas power generation devices in accordance with the power generation demand. However, a technology for controlling the digestion gas power generation system from the viewpoint of the entire power supply system has not yet been developed.

JP-A-8-298723

  The present invention has been made in consideration of such points, and an object thereof is to provide a digestion gas power generation system that can be controlled from the viewpoint of the entire power supply system.

  The embodiment of the present invention uses a digestion tank that generates digestion gas containing methane gas from sewage sludge, a methane gas generation apparatus that generates methane gas using digestion gas from the digestion tank, and methane gas from the methane gas generation apparatus. Digestion gas power generation device for generating power, charging the power generated by the digestion gas power generation device and capable of discharging, a methane gas tank for storing methane gas from the methane gas generation device, the digestion tank, A control unit that controls the methane gas generation device, the digestion gas power generation device, the power storage device, and the methane gas tank, and the control unit adjusts the methane gas from the methane gas generation device to meet the power demand. And selectively supplied to the methane gas tank and generated by the digestion gas power generation device. Sending a force to the power grid, a digestion gas power generation system characterized by charging the remaining power to the power storage device.

  In the embodiment of the present invention, the digestion gas power generation device includes a plurality of power generation devices, and the control unit controls the number of the power generation devices to supply power to the power system, and discharges the power storage device. It is a digestion gas power generation system characterized by supplying power to an electric power system.

  An embodiment of the present invention is a digestion gas power generation system in which the control unit discharges the power storage device and supplies power to the power system, and supplies power from the digestion gas power generation device to the power system.

  An embodiment of the present invention is a digestion gas power generation system, wherein the control unit discharges the power storage device and suppresses fluctuations in electric power from the digestion gas power generation device.

  The form of this invention WHEREIN: The said control part calculates | requires an electric power demand predicted value based on calendar information, weather information, and track record information, and controls the said digestion gas power generation device based on this electric power generation demand predicted value. Digestion gas power generation system.

  In the embodiment of the present invention, the control unit predicts a digestion gas generation amount based on an inflow amount and properties of sewage sludge, and controls the digestion gas power generation device based on the power generation demand prediction value and the digestion gas generation amount. This is a digestion gas power generation system.

  An embodiment of the present invention is a digestion gas power generation system including a power transmission system that transmits surplus power to an electric power company, and the control unit discharges the power storage device to the power transmission system. .

  An embodiment of the present invention is a digestion gas power generation system in which the control unit controls the digestion gas power generation device, the power storage device, and the methane gas generation device based on a predetermined charge / discharge plan.

  The form of this invention is the digestion gas power generation system characterized by the said control part judging the normal time or the time of a power failure of a general power supply from the state of an electric power system, a protection relay, or a circuit breaker.

  In the embodiment of the present invention, the control unit obtains a power demand prediction value based on calendar information, weather information, and performance information, and controls the power storage device based on the power generation demand prediction value. It is a power generation system.

  An embodiment of the present invention is a digestion gas power generation system characterized in that a power storage device PCS is provided between the power storage device and the power supply system.

  As described above, according to the present embodiment, the control unit supplies digestion gas to the digestion gas power generation device and the methane gas generation device in accordance with the power generation demand, and charges the power storage device with the power generated by the digestion gas power generation device. can do.

The functional block diagram which shows the digestion gas power generation system of this invention. The schematic system diagram which shows the digestion gas power generation system of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, the digestion gas power generation system 10 will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the digestion gas power generation system 10 is processed by a digestion tank 11 that generates digestion gas containing methane gas from sewage sludge, a digestion gas pretreatment unit 12, and a pretreatment unit 12. Charging methane gas generating device 20 that generates methane gas using digestion gas, digestion gas power generating device 16 that generates power using methane gas generated by methane gas generating device 20, and electric power generated by digestion gas power generating device 16; The discharging power storage device 30, the methane gas tank 21 storing methane gas from the methane gas generation device 20, the digestion tank 11, the pretreatment unit 12, the methane gas generation device 20, the digestion gas power generation device 16, the power storage device 30, and the methane gas tank 21. And a control unit 40 composed of an EMS controller or the like for controlling the control.

  The digestion gas containing methane gas generated in the digestion tank 11 further contains carbon dioxide, hydrogen sulfide, siloxane, ammonia and the like in addition to methane gas.

  For this reason, the digestion gas generated in the digestion gas tank 11 is processed by the pretreatment device 12, and the siloxane in the digestion gas is removed. In this case, as the pretreatment device 12, a device having a gas cooler 13 that cools digestion gas, a booster blower 14, and a pretreatment tower 15 is used.

  In addition, the digestion gas power generation device 16 has a plurality of power generation devices 16a, 16b..., And the number of digestion gas power generation devices 16 can be controlled by the control unit 40.

  By the way, the digestion gas power generation device 16 is of a gas engine type, the digestion gas power generation device 16 is cooled by cooling water passing through the cooling line 18, and the cooling water heated by the digestion gas power generation device 16 is digestion tank heating device. 17 is heated.

  Furthermore, the methane gas produced | generated by the methane gas production | generation apparatus 20 can be sent to the digestion gas generation apparatus 16, or can be temporarily stored in the methane gas tank 21. FIG. The methane gas stored in the methane gas tank 21 is then sent to the digestion gas power generation device 16. The digestion gas power generation device 16 generates power using methane gas directly supplied from the methane gas generation device 20 or methane gas supplied from the methane gas tank 21.

  Next, the operation of the present embodiment having such a configuration will be described.

  First, sewage sludge is introduced into the digestion tank 11, and digestion gas containing methane gas is generated in the digestion tank 11. Digestion gas generated in the digestion tank 11 sequentially passes through the gas cooler 13, the booster blower 14 and the pretreatment tower 15 of the pretreatment device 12, and during this time siloxane in the digestion gas is removed.

  Next, the digestion gas pretreated by the pretreatment device 12 is sent to the methane gas generation device 20, and the methane gas generation device 20 generates methane gas from the digestion gas. A part of the methane gas generated by the methane gas generation device 20 is sent to the digestion gas power generation device 16, and the digestion gas power generation device 16 generates power using the digestion gas. And the remainder of the methane gas produced | generated in the methane gas production | generation apparatus 20 is sent to the methane gas tank 21, and is stored.

  During this time, the digestion gas power generation device 16 is cooled by the cooling water flowing through the cooling line 18, and the cooling water heated by the digestion gas power generation device 16 is sent to the digestion tank heating device 17. Heat.

  Next, the control method of the digestion gas power generation system 10 executed by the control unit 40 will be described in detail.

  As described above, the control unit 40 includes an EMS controller and the like, and is monitored and controlled by the monitoring device 41 installed in the central monitoring room 41a, and controls the digestion gas power generation system 10 from the viewpoint of the entire power supply system.

  That is, the control unit 40 controls the digestion gas power generation device 16 and the power storage device 30 to supply (sell) power to the general power supply system 45 via the receiving / transforming electric power control unit 42. Yes. Alternatively, general power may be supplied from the general power supply system 45 to the receiving / changing electric force control unit 42 as necessary.

  In addition, information from each device is input to the control unit 40, and the control unit 40 controls driving of each device.

  Specifically, during normal operation of the power supply system, the control unit 40 obtains a power demand predicted value based on calendar information, weather information, and past performance information. Next, the control unit 40 determines the supply amount of methane gas to be directly supplied to the digestion gas power generation device 16 among the methane gas processed by the pretreatment device 12 and generated by the methane gas generation device 20 based on the predicted power demand value. The remainder of the methane gas generated by the methane gas generation device 20 is supplied to the methane gas tank 21.

  In this case, the control unit 40 predicts the digestion gas generation amount based on the inflow amount and the property of the sewage sludge, and considers the power demand prediction value and the digestion gas generation amount prediction value, and the methane gas generation device 20. The supply amount of the methane gas that is directly supplied to the digestion gas power generation device 16 among the methane gas generated in step 1 may be determined.

  Next, the control unit 40 determines the number of power generation devices 16a, 16b,. Next, the electric power generated by the digestion gas power generation device 16 is supplied (sold) to the general power supply system 45 through the variable electric power control unit 42 to reduce the power peak of the power supply system 45. .

  During this time, surplus power generated by the digestion gas power generation device 16 is charged in the power storage device 30.

  On the other hand, the remainder of the methane gas produced | generated with the methane gas production | generation apparatus 20 is sent to the methane gas tank 21, and is stored. And the control part 40 further sends the methane gas stored in the methane gas tank 21 to the digestion gas generator 16 as needed, and generates electric power.

  Moreover, the control part 40 discharges the power supply device 30 as needed based on an electric power demand prediction value. The electric power discharged from the power supply device 30 is sent to the power supply system 45 via the receiving / changing electric force control unit 42.

  Next, the control part 40 performs the following control at the time of a power failure. First, the supply amount of methane gas to be directly supplied to the digestion gas power generation device 16 among the methane gas processed by the pretreatment device 12 and generated by the methane gas generation device 20 is determined.

  Next, the control unit 40 determines the number of power generation devices 16a, 16b,. Next, the electric power generated by the digestion gas power generation device 16 is supplied to the general power supply system 45 via the power receiving / transforming electric power control unit 42 (sold), and power is supplied from the power supply system 45 in a power failure state. Supply.

  During this time, surplus power generated by the digestion gas power generation device 16 is charged in the power storage device 30.

  On the other hand, the remainder of the methane gas produced | generated with the methane gas production | generation apparatus 20 is sent to the methane gas tank 21, and is stored. Further, the control unit 40 further generates methane gas stored in the methane gas tank 21 to the digestion gas generator 16 as necessary to generate power, and the power generated by the digestion gas generator 16 is charged into the power storage device 30. Is done.

  Moreover, the control part 40 discharges the electrical storage apparatus 30 as needed so that the electric power supply amount at the time of a power failure may be supplemented. The electric power discharged from the power storage device 30 is sent to the power supply system 45 via the power receiving / transforming electric power control unit 42 (sold).

  At the time of a power failure, control unit 40 supplies power so as to suppress fluctuations in power supply system 45 when discharging from power storage device 30.

  By the way, signals are input from the power supply system 45, the protective relay and the circuit breaker to the control unit 40, and the control unit 40 can determine the power failure state or the normal state of the power supply system 45 based on these signals.

  In addition, a power transmission system (not shown) for transmitting surplus power to an existing electric power company is connected to the receiving / changing electric power control unit 42. Control unit 40 can transmit surplus power by discharging from power storage device 30 to the power transmission system.

  As described above, according to the present embodiment, the digestion gas power generation system can be controlled from the viewpoint of the entire power supply system, and excess digestion gas that is not used in the digestion gas power generation device 16 is not released. Methane gas can be generated from this digestion gas, and this methane gas can be used in the methane gas power generation device 22, so that the digestion gas can be effectively used.

  In the above-described embodiment, the control unit 40 obtains the predicted power demand value at the normal time, and the digest gas generator 16 and the power storage device 30 are controlled based on the predicted power demand value. However, the present invention is not limited thereto. Instead, the digestion gas power generation device 16 and the power storage device 40 may be controlled based on a predetermined charging / discharging plan. Further, a power storage device PCS may be installed between the power storage device 30 and the power supply system 45.

DESCRIPTION OF SYMBOLS 10 Digestion gas power generation system 11 Digestion tank 12 Pretreatment apparatus 16 Digestion gas power generation apparatus 16a, 16b Power generation apparatus 20 Methane gas production | generation apparatus 21 Methane gas tank 22 Methane gas power generation apparatus 30 Power storage apparatus 40 Control part 42 Variable electric power control unit 45 Power supply system

Claims (11)

A digester that generates digestive gas containing methane gas from sewage sludge;
A methane gas generator that generates methane gas using digestion gas from the digestion tank;
A digestion gas power generation device that generates power using methane gas from the methane gas generation device;
A power storage device capable of charging and discharging the power generated by the digestion gas power generation device; and
A methane gas tank for storing methane gas from the methane gas generator,
The digester, the methane gas generator, the digestion gas power generation device, said power storage device, and a control unit for controlling the methane gas tank, the control unit based on the power demand prediction value, generated by the methane gas generator Of the generated methane gas, the supply amount of methane gas to be directly supplied to the digestion gas power generation device is determined and supplied to the digestion gas power generation device, and the remainder of the methane gas generated by the methane gas generation device is supplied to the methane gas tank and stored. And
The control unit operates the digestion gas power generation device based on the predicted power demand value, sends the power generated by the digestion gas power generation device to the power system, and charges the remaining power to the power storage device. Digestion gas power generation system characterized by that. The digestion gas power generation device includes a plurality of power generation devices,
Wherein the control unit is configured to supply power to the power system by performing installation control of the power generation device, digestion gas power generation system of claim 1, wherein the feeding is performed to discharge of said power storage device to the power system . The control unit feeds power by performing discharge of said power storage device to the power system, digestion gas power generation system of claim 1, wherein the powered from the digestion gas generator apparatus to the power system.   The digestion gas power generation system according to claim 1, wherein the control unit discharges the power storage device and suppresses fluctuations in electric power from the digestion gas power generation device. The said control part calculates | requires the said electric power demand predicted value based on calendar information, weather information, and track record information, and controls the said digestion gas power generation device based on this electric power demand predicted value. Digestion gas power generation system. The control unit predicts a digestion gas generation amount based on an inflow amount and properties of sewage sludge, and controls the digestion gas power generation device based on the predicted power demand value and the digestion gas generation amount. The digestion gas power generation system according to claim 5. It has a power transmission system that transmits surplus power to the power company,
The digestion gas power generation system according to claim 1, wherein the control unit discharges the power storage device to the power transmission system.   The digestion gas power generation system according to claim 1, wherein the control unit controls the digestion gas power generation device, the power storage device, and the methane gas generation device based on a predetermined charge / discharge plan.   The digestion gas power generation system according to claim 1, wherein the control unit determines whether the general power supply is normal or during a power failure from the state of the power system, the protective relay, or the circuit breaker. Wherein the control unit, calendar information, weather information, obtains the power demand prediction value based on the record information, digester gas according to claim 1, wherein the controller controls the power storage device on the basis of the power demand prediction value Power generation system. Digestion gas power generation system of claim 1, wherein between said power storage device and said power system integration, characterized in that the power storage device for PCS is provided.

Images