JPS59508A - Electric power generation and apparatus by boiler and hot-water accumulator - Google Patents

Abstract

PURPOSE:To obtain the high efficient electric power generation system by a method wherein the hot-water obtained from an accumulator is supplied to a hot-water turbine, the thermal energy is recovered, then the saturated vapor is separated by a separator, the electrical power is generated by supplying the flashing steam to the turbine. CONSTITUTION:A upper space 18 of an accumulator 24 receives a high temperature hot-water from the outlet pipe of a boiler 1, and is filled up by the saturated vapor. A high temperature hot-water 19 and a low temperature hot-water 20 are formed as such layers having a surface 21 as a boundary of each layer at the lower part of the space 18. The high temperature hot-water 19 is collected by a water collector 23, supplied to a high temperature hot-water turbine 5', utilized for the electric power generation, further, after flashing by a vapor- water separator 7', the saturated vapor decreased its pressure is supplied to a steam turbine 5, a generator 6 generates the electric power correspond to the adiabatic expansion down to the vacuume pressure of a steam condenser 7.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for power generation using a boiler and a hot water accumulator.

There are various methods for generating electricity by storing thermal energy generated in a boiler in a steam accumulator and releasing it when necessary to supply the generated steam to a turbine generator or the like. For example, in the case of a power generation system using a diesel generator, etc. used for power supply on remote islands, etc., in order to cover the electricity during peak loads, a waste heat boiler is attached to recover the waste heat of the diesel engine, and the recovered thermal energy is is stored in a steam accumulator, and at peak load, steam is released from the accumulator to drive a turbine generator.
Electric power generated by this turbine generator is supplied to a load.

A general system configuration conventionally used as a waste heat recovery turbine power generation system for this purpose is as shown in FIG. In other words, in Fig. 1, this type of power generation system conventionally includes a waste heat boiler (1) that is operated using waste heat of exhaust gas from the engine exhaust system of diesel power generation equipment, a steam separator Q) and a water supply pump ( 6), a variable pressure steam accumulator (4) that stores the steam generated from the cono boiler system as hot water, and a turbine system that drives a steam turbine (5) and generates electricity with a generator (6). For example, during low load in the morning, waste heat from diesel power generation equipment is recovered in the boiler (1) and stored in the accumulator (4), and during peak load in the evening, the pressure in the accumulator (4) is lowered and the required amount is recovered. is evaporated and turns the turbine (5), which triggers the turbine (5).
6) to supplement the output of the diesel generator. In this case, the steam used to generate power within the turbine (5) is the condenser (7), condensate pump (8), make-up water tank (9), make-up water pump (1o), and feed water heater (11). It returns to the water supply side of the brackish water separator (2) through
It circulates again to the boiler (1).

In such conventional power generation systems, the highest pressure of the boiler pressure cuff accumulator (4) is connected to piping and the accumulator (4).
4) The boiler (1) is operated so as to maintain a constant pressure including the resistance of the steam jet nozzle, etc., and therefore the temperature of the heat transfer surface of the boiler (1) becomes higher than the saturation temperature of the operating boiler pressure. For this reason, disadvantages such as narrowing the waste heat recovery limit in the waste heat boiler (1) and requiring a large heat transfer area for the same amount of heat recovery cannot be avoided. However, if an attempt is made to increase the amount of heat storage per unit volume, the tendency of the above-mentioned drawbacks will increase as the boiler pressure increases.

This invention is an economically advantageous power generation system that eliminates the above-mentioned drawbacks.In a power generation system using a diesel generator or the like that is used for power supply on remote islands etc., this invention is equipped with a hot water boiler for waste heat and recovers heat. The purpose of this system is to store energy in the form of high-pressure hot water in an accumulator, supply hot water at peak loads, and provide a highly efficient system for driving turbine generators and generating electricity.

That is, in this invention, high-pressure, high-temperature water is generated in a boiler, stored in a hot water accumulator, and when required, the high-temperature water is taken out in a high-pressure state and supplied to a turbine system that is power generation equipment. The accumulator is vertically shaped, with high-temperature water in the upper part of the accumulator and low-temperature water in the lower part of the accumulator that returns after being used for the power generation equipment, and is stored in upper and lower layers.Also, a gap is provided above the high-temperature water to store saturated steam of the high-temperature water. This fills the inside of the accumulator with the saturation pressure of high-temperature water.

In addition, the low-temperature pressure water obtained from the hot water turbine, which is a power generation equipment, does not lose its temperature and pressure, and the condensed water from the steam turbine is returned to the bottom of the accumulator immediately after recovering thermal energy, so that it is always kept constant in the accumulator. By storing a certain amount of liquid, it is possible to supply water to the boiler at an appropriate temperature that does not cause sulfuric acid corrosion without causing any hindrance to the removal of high-temperature water from the high-temperature area at the top of the accumulator, and from the bottom of the accumulator using the reboiler water supply pump. It is something to tighten. In this case, the device is such that a cylindrical body for rectifying flow and promoting natural circulation is placed inside the accumulator parallel to the axis, and the upper layer of high-temperature water is collected and supplied to the upper part of the accumulator without introducing steam. A boiler system comprising a water collector, a valve and a control mechanism for controlling the temperature of high-pressure, high-temperature water from the boiler, and a valve and control mechanism for controlling return water to keep the liquid level inside the accumulator constant. and a turbine system consisting of a hot water turbine and a steam turbine connected to each other, each of which is equipped with a condensing mechanism.

Embodiments using the present invention will be described below with reference to the drawings. FIG. 2 is a system diagram showing the configuration of a waste heat recovery power generation system according to an embodiment of the present invention, and the same reference numerals as in FIG. 1 indicate the same effects. (1) is a waste heat boiler,
(6) is a boiler feed water pump, (5 is a hot water turbine, (
5) is a steam turbine, (6) is a generator, (7) is a steam condenser, [F]) is a condensate pump, (9) is a makeup water tank, (10) is a condensate return pump, (13) is A heat exchanger for condensate heating, for example, between the engine cooling water of a diesel generator that recovers waste heat in the boiler (1) and the steam condenser (7).
), (7') is a brackish water separation tank, (10') is a flushing water return pump,
(15) is a makeup water flow control valve, (15') is a return water control valve, (25) is a return water controller, (16) is a hot water throttle control valve, (17) is a water supply controller, (18) is the steam space of the hot water accumulator, (19) is the high temperature water in the hot water accumulator, (20) is the low temperature water, (21) is the interface between high temperature water and low temperature water, (22) is the cylindrical body, ( 20) is a high-temperature water collector, and (24) is an accumulator body.

In the boiler system in the system of this invention, the boiler (1
) forms a loop with the accumulator (24) and the water supply pump (6) via the throttle control valve (16) installed in its outlet pipe, while the turbine system also forms a loop via the accumulator (24). Closed.

The throttle control valve (16) is a hot water outlet temperature control device (17)
By monitoring the hot water temperature in the outlet pipe of the boiler (1) and controlling the outlet pipe hot water flow rate by adjusting the opening,
The hot water temperature at the outlet of the boiler (1) is measured by the accumulator (24).
The temperature is maintained at the saturation temperature corresponding to the maximum pressure of The boiler (1) is operated as a hot water boiler under the control of the throttle control valve (16), and high temperature water from the outlet pipe is passed through the control valve (16).
) and then sent into the upper space (18) of the accumulator (24). The upper space (18) of the accumulator (24) is filled with saturated steam at its highest pressure, and the lower part contains high-temperature water (19) that has stored heat, and the lower part contains low-temperature water at the saturation temperature of the lowest pressure of the accumulator. (20
) is stored as two-layer water with an interface (21) in between.

A cylindrical body (22) is disposed within the accumulator (24) to store this two-layer water, and its rectifying action prevents disturbances at the interface due to flushing or the like. Furthermore, the accumulator (24) is further provided with a water collector (23) which collects the high temperature water in the upper layer in the upper part thereof, prevents the generation of vortices therein, and extracts and supplies steam without drawing it in. The accumulator (24
) The high temperature water collected by the water collector (23) at the upper part of the turbine is taken out and supplied through the turbine inlet control valve (12). The steam used for power generation in the hot water turbine (51) is lashed 7 times in a steam separator (7), and then the saturated steam after depressurization is supplied to the steam turbine (5), which is then sent to the condenser (5) by the generator (6).
7) Power generation corresponding to the adiabatic expansion of vacuum pressure loss is performed. The steam used for power in the steam turbine (5) is transferred to the condenser V.
) is sent to the make-up water tank (9) via the condensate pump (8), heated by the condensate heating heat exchanger (13) via the pump (10), and then heated by the control valve (15). Via
The flushing water separated by the brackish water separator (7') is mixed to a predetermined temperature via the flushing water return pump (10') and returned to the lower part of the accumulator (24). In order to keep the liquid level inside the accumulator constant, the flow rate of the return water of these condensates is determined by detecting the level inside the accumulator (24) via the return water control valve (15'). 25) and is fed to the lower part of the accumulator (24) and again to the boiler (1) via the water supply pot (9).

With the above configuration, this device produces high-pressure, high-temperature water in a boiler, stores the obtained high-pressure, high-temperature water in an accumulator, and takes out the high-temperature water when needed and supplies it to the bottle system to generate electricity. The inside of the accumulator always stores hot water at a constant volume, that is, at the same level.The upper space is filled with high-temperature water, the lower part is with low-temperature water, and the upper space is filled with saturated steam of high-temperature water, and the entire inside of the accumulator is filled with saturated steam of high-temperature water. is characterized by the saturation pressure of high temperature water.

In one embodiment of the invention, 2 Q ata of saturated water with a saturation temperature of 211° C. is supplied from the upper part of the accumulator (24) by the waste gas boiler (1) of the diesel engine. At the bottom of the accumulator (24), there is a hot water turbine (expanded to 4 ata at 5 increments, and then a brackish water separator (7 ata).
4ata14 after evaporation to saturation of 4ata in a vacuum cleaner
The 3C saturated water and the saturated steam separated in the steam water separator (7') are expanded to 0.1 ata in the steam turbine (5), that is, generate electricity, and then transferred to the steam condenser (7) → condensate pump (8).
) → Make-up water tank <9) → Via the condensate return pump (10), it is mixed with condensate heated in the condensate heating exchanger (16) until it reaches 75C with diesel engine cooling fresh water of 85C, and is mixed with condensate heated in the condensate heating exchanger (16).
The return water becomes 4C and is stored as low temperature water via the return water control valve (15'). Heat storage is normally carried out throughout the day, and the low temperature water (20) at the bottom of the accumulator (24) is supplied via the boiler feed pump (6), and the planned high temperature water temperature is maintained by the nine temperature control throttle valves (16) at the boiler outlet. It is regulated and supplied from the top of the accumulator (24). In this case, the boiler is a hot water boiler without evaporation, and the flow is completely opposite to the waste gas, so a sufficient temperature difference can be obtained, so a small heat transfer area is good. In addition, the present invention connects and arranges a hot water turbine and a steam turbine, efficiently collects and takes out the surface high temperature water of the accumulator (24), and supplies only the high temperature water to the hot water turbine first, thereby converting the thermal energy of the high pressure and high temperature water. Mechanical output is increased by recovering the water using a hydrothermal turbine.

That is, in a turbine system, when recovering thermal energy from 20 ata of high-pressure saturated water using a steam turbine, at one end A a
In contrast, in the method of the present invention, high-pressure hot water performs adiabatic expansion work until d ata and then saturated steam at 4 ata after being throttled up to ta and then performing adiabatic expansion work on the condenser vacuum with saturated steam after depressurization. Since the condenser vacuum works again, an increase in mechanical output (power) of several tens of inches can be obtained despite the same amount of recovered heat. By returning the pressure hot water at the outlet of the hot water turbine to the hot water accumulator without reducing the pressure, it is possible to save the pressurizing energy required to supply water to the boiler again, and to reduce the temperature of the water supply at the boiler inlet, which may cause acid corrosion of the boiler tubes. It has many advantages, such as the fact that it is easy to maintain a temperature of, for example, 163.5C.

As described above, according to the present invention, the boiler is always operated as a hot water boiler, so there is no evaporation of hot water in the boiler heat exchanger tubes, the temperature of the water supplied to the boiler is constant, and the outlet temperature is also controlled to be constant. The heat transfer area of the boiler can be used effectively, and the condensate in the turbine system can be returned to the bottom of the accumulator without being decompressed, keeping the liquid level in the accumulator constant, making the thermal energy or waste heat of combustion gas highly efficient. By configuring the recovered thermal energy in the turbine system as described above, an increase in power generation efficiency can be expected. Furthermore, the accumulator does not require a complicated mechanism such as a large number of steam jetting nozzles as in the past, and is a suitable power generation method and power generation device for supplying power during peak load times of diesel power generation equipment.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing an example of a conventional waste heat recovery power generation system, and FIG. 2 is a system diagram showing an embodiment of the present invention. 1: Waste heat boiler, 5: Steam turbine, 5': Hot water turbine, 6: Generator, 7': Brackish water separator, 15': Return water control valve, 16: Throttle control valve, 22: Cylindrical body, 23: Water collector, 24: Accumulator, 25: Return water controller. Representative Patent Attorney Sanro Kimura

Claims (1)

[Scope of Claims] (1) In a method for storing thermal energy generated in a boiler in a hot water accumulator and generating electricity using the energy released from the accumulator, the boiler is operated in a controlled manner as a hot water boiler, and the accumulator is operated in an upper space area. , has a high-temperature water area and a low-temperature water area, and extracts high-temperature water from the accumulator and supplies it to a hydrothermal turbine to recover thermal energy.
A power generation method using a boiler and a hot water accumulator, characterized in that the i-wa steam is then separated in a steam separator, and the 7 lashing steam is supplied to a steam turbine to generate power. (2) The 7 lashing water obtained from the brackish water separator and the molten condensate water obtained from the steam turbine are mixed, supplied to the low-temperature water area of the accumulator, and then circulated and supplied as feed water to the boiler. The method of claim 1, characterized in: (6) When mixing the flushing water from the steam water separator and the condensate obtained from the steam turbine and replenishing the low temperature region of the accumulator, heat exchange the condensate with a heat exchanger, 2. The method according to claim 1, wherein the temperature of make-up water in the accumulator is controlled by the temperature and amount of condensate. (4) In a device that stores thermal energy generated in a boiler in a hot water accumulator and uses the energy released from the accumulator to generate electricity, a valve and control equipment for controlling high-temperature water from the boiler are connected to the outlet of the boiler and the upper inlet of the accumulator. The hot water in the upper high temperature area of the accumulator is taken out, and the hot water is supplied to a power generation device consisting of a hot water turbine and a steam turbine, which recovers the heat energy and generates electricity. A valve and a control device for controlling and using condensate from a hot water turbine and a steam turbine as return water to the accumulator are provided between a return water conduit leading to a lower part of the accumulator, and a valve and a control device are provided between the return water conduits leading to the lower part of the accumulator, and the low-temperature water from the accumulator is connected to the boiler. A power generation device comprising a boiler and a hot water accumulator, characterized in that it is equipped with a conduit for use as a water supply. (5) A patent claim characterized in that the hot water accumulator is vertical, and includes a concentric cylindrical body in the low temperature region inside the accumulator, and a water collector in the high temperature region. Devices within the scope of item 4.