JP5538458B2 - Steam supply plant and solar heat insulation device - Google Patents

Description

  The present invention relates to a steam supply plant provided with a heat retaining device for a steam pipe that pumps steam generated in a boiler or the like.

  A combined heat and power system (cogeneration system, cogeneration system) has been proposed as a system that obtains electric power from the rotational kinetic energy of internal combustion engines such as gas turbines and gas engines, and collects thermal energy from the exhaust gas of the engines to obtain steam or hot water. ing.

  The cogeneration system collects and directly uses low-temperature heat energy, which is difficult to convert into electric energy with conventional power generation systems, as high-temperature and high-pressure steam and hot water, and improves the overall energy efficiency of the system. Suitable for introduction to facilities and areas that require steam and hot water. An exhaust heat recovery boiler is effective as a means for obtaining high-temperature and high-pressure steam. The steam obtained by the exhaust heat recovery boiler can be supplied to a steam consuming facility (for example, a factory that requires steam, a house for air conditioning or the like) through a steam pipe.

  When pumping steam through the steam pipe, as a means to reduce heat loss (steam temperature drop) from the exhaust heat recovery boiler to the steam consuming equipment, cover the steam pipe with insulation, heat insulation of the pipe with heating wires, and pipe heating There is pipe insulation using steam as a source. As an example, Patent Literature 1 relates to a steam trace device that uses steam to heat a fuel pipe or the like, and discloses a technique for controlling a steam flow rate that is a heating source in accordance with a temperature drop of the pipe.

JP 2006-46476 A

  However, the steam tracing device described in Patent Literature 1 requires boiler generated steam as a heating source. Moreover, the heat retention method using a heating wire requires electric power for generating heat. In addition, in the system which coat | covers steam piping only with a heat insulating material, especially when the distance from a boiler to steam consumption equipment is long, the reduction effect of a heat loss becomes limited.

  The objective of this invention is providing the steam supply plant which can suppress the heat loss of steam piping, without using the steam and electric power of a boiler as a heat source for heat-retaining a steam piping.

In order to solve the above-described object, a steam supply plant of the present invention collects solar heat in a steam supply plant including a boiler that generates steam and a steam pipe that supplies steam generated by the boiler to steam consuming equipment. A heat collector that heats the medium, a heater that retains or heats the steam pipe using the medium heated by the heat collector, and a circulation pump that recirculates the medium via the heater to the heat collector. The heater has a plurality of electric heating tubes and a flexible pipe connected to each of the plurality of electric heating tubes, and the flexible pipe is wound around in the circumferential direction of the steam piping. It is characterized by being removable .

  ADVANTAGE OF THE INVENTION According to this invention, the steam supply plant which suppressed the heat loss of steam piping can be provided, without using the steam and electric power of a boiler as a heat source of the heat insulation of steam piping.

The system flow figure of the solar thermal pipe heat retention apparatus which is one Example of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a heater structure diagram of a solar heat pipe heat retention device according to an embodiment of the present invention. Steam pipe temperature characteristics by the solar heat pipe heat insulating device of this example. The steam pipe pressure characteristic by the solar heat pipe heat insulation apparatus of a present Example.

  An embodiment of the present invention will be described with reference to FIG. In this embodiment, a cogeneration system (hereinafter referred to as a cogeneration system) using a gas turbine and an exhaust heat recovery boiler will be described as an example. FIG. 1 is an overall system diagram of a cogeneration system using a solar heat pipe heat insulating device.

  In this embodiment, a solar heat pipe heat retaining device 5, solar heat is added to a cogeneration system including a gas turbine 1 (internal combustion engine), a boiler 2 (exhaust heat recovery boiler), a steam pipe 3, a pressure regulating valve 4 and a steam consuming equipment 9. A solar heat pipe heat retaining system including a pipe heat retaining device control means 10 and a boiler control means 11 is provided.

  The gas turbine 1 drives the turbine with the energy of combustion gas obtained by combusting fuel together with air, generates power using this driving force as rotational energy, and sends the combustion gas after driving the turbine to the boiler 2 as exhaust gas. The boiler 2 generates steam by boiling and evaporating the feed water with the heat energy of the exhaust gas. Further, the steam is pumped to the steam consuming equipment 9 through the steam pipe 3. The pressure of the steam is adjusted by a pressure regulating valve 4 installed at the boiler 2 outlet.

  For such a cogeneration system, the solar heat pipe heat insulating device 5 of the present embodiment includes a heat collector 6, a heater 7, and a circulation pump 8. Further, as a control system for the solar heat pipe heat insulation device, steam consumption facility inlet steam temperature measurement means 16, steam consumption facility inlet steam pressure measurement means 14, solar altitude measuring device 20, boiler steam pressure measurement means 12, solar heat pipe heat insulation device control means 10 The boiler control means 11 is provided.

  The heat collector 6 collects sunlight from solar heat energy into a pipe installed in front of the mirror using a curved mirror, and heats a medium flowing in the pipe. The curved mirror is arranged so that the pipe is located in the east-west direction, and the amount of heat collected in the pipe can be adjusted by changing the angle of the mirror with a gear, a motor, or the like. In addition, assuming that the inside of the pipe is equal to or higher than the boiling point of water, oil having a high flash point is used.

  The heater 7 is a device that heats the steam pipe 3 using the high-temperature medium obtained by the heat collector 6. An example of the structure of the heater 7 is shown in FIG. In order to make the heater attachable to and detachable from the pipe, the heater is composed of a plurality of small-diameter heat transfer tubes 22 and a flexible pipe 23 that can be bent, and a binding belt or the like is used in the direction of arrow K (circumferential direction) in the figure. The structure shall be wound around the steam pipe. The refrigerant is introduced from X in the figure, and the flexible pipe 23 is extracted from Y through the heat transfer tube 22 and another flexible pipe 24. The refrigerant extracted from Y returns to the circulation pump. Furthermore, in order to prevent the heat energy of the medium flowing in the pipe from being released into the atmosphere, the heat transfer tube 22 may be covered and a heat insulating material may be wound around. In addition, as shown by the arrow in the figure, the steam flow direction A of the steam pipe 3 and the medium flow direction B of the heat transfer tube 22 are configured to face each other, ensuring a temperature difference between the steam and the medium, from the steam to the medium. Promotes heat conduction.

The embodiment of the present invention will be described with reference again to FIG.
The medium from the heater 7 is configured to flow again into the heat collector 6 through the circulation pump 8. In this figure, the medium from the heater is directly supplied to the circulation pump. However, the medium from the heater may be stored in an oil tank or the like, and the circulation pump may extract the oil in the tank.

The control system of the solar heat pipe heat insulating device 5 described above will be described.
The control system includes a solar heat pipe heat retaining device control means 10, a solar altitude measuring device 20, a steam consumption facility inlet steam pressure measurement means 14, a steam consumption facility inlet steam temperature measurement means 16, a boiler control means 11 and a boiler steam pressure measurement means 12. Prepare.

  The solar heat pipe heat retaining device control means 10 inputs the steam consumption facility inlet steam temperature 17 from the steam consumption facility inlet steam temperature measurement means 16 and the solar altitude 21 from the solar altitude measuring device 20, and controls the heat collector 6 as a control command. The collector angle command 18 is output. That is, when the steam consumption facility inlet steam temperature measuring means 16 is lower than the target set temperature in the solar heat pipe heat retaining device control means 10, the heat collector angle command 18 is calculated so that the elevation angle of the heat collector follows the solar altitude. Further, when the steam consumption facility inlet steam temperature measuring means 16 is higher than the target set temperature, the collector angle command 18 is calculated so that the elevation angle of the collector is smaller than the solar altitude (horizontal direction).

  In addition, when the distance of the solar heat pipe heat insulation apparatus 5 and the steam consumption equipment 9 is separated, the measurement signal from the steam consumption equipment entrance steam temperature measurement means 16 is wirelessly transmitted to the solar heat pipe heat insulation apparatus control means 10. It is good also as a structure.

  Next, the boiler control means 11 inputs the steam consumption facility inlet steam pressure 15 from the steam consumption facility inlet steam pressure measurement means 14 and the boiler steam pressure 13 from the boiler steam pressure measurement means 12, and the pressure regulating valve 4 as a control command. In response to this, a pressure adjustment valve opening command 19 is output. More specifically, the difference between the steam consumption facility inlet steam pressure 15 and the steam consumption facility inlet steam pressure 15 is obtained in the boiler control means 11, and this difference is added to the boiler steam pressure 13 target pressure. A boiler steam pressure control target correction value is obtained. Further, the pressure regulating valve 4 is calculated so that the boiler steam pressure 13 matches the boiler steam pressure control target correction value. In addition, this control controls the fluctuation | variation of the steam consumption in the steam consumption equipment 9, and the fluctuation | variation of the steam pressure accompanying the fluctuation | variation of the turbine output in the gas turbine 1, and the steam pressure loss from a boiler to a steam consumption equipment is used as a boiler exit steam. By maintaining the pressure at a high level, the quality of the steam is maintained, and the generation of drain due to the pressure drop in the middle of the piping is prevented.

The operation results of the solar heat pipe heat insulating device 5 described above are shown in FIGS.
FIG. 3 is a schematic diagram of the steam temperature in the steam pipe when two solar heat pipe heat retaining devices 5 are installed in the middle of the steam pipe to keep the pipe warm.

  In the figure, the horizontal axis represents the pipe length, and it is assumed that the pipe length 0 is the boiler outlet and the pipe length L is the steam consumption facility inlet. Moreover, the solar heat piping heat retention apparatus is each installed in two points, H1 and H2.

On the other hand, the vertical axis in the figure represents the steam temperature in the steam pipe. When the steam temperature at the boiler outlet is T ₀ , the steam temperature is lowered according to the distance of the steam pipe when the solar heat pipe heat retaining device 5 of the present invention is not applied. The figure shows that the temperature has dropped to T at the steam consumption facility entrance.

On the other hand, when the solar heat pipe heat insulating device 5 of the present embodiment is applied, the steam temperature rises at each point by performing steam heating by solar heat at the points H1 and H2 in the figure. The steam temperature at the consumption facility inlet is T ′, and the steam can be pumped without a temperature drop from the steam temperature T _{0 at} the boiler outlet.

FIG. 4 is a schematic diagram of the steam pressure in the steam pipe under the same conditions as FIG.
The horizontal axis in the figure represents the pipe length as in FIG. The vertical axis in the figure represents the steam pressure in the steam pipe. If the steam pressure at the boiler outlet is pumped at P ₀ without applying the solar heat insulation apparatus of the present invention, the pressure decreases according to the flow velocity of the steam flowing in the pipe and the pipe length. The pressure drops to P.

On the other hand, when the solar heat pipe heat insulation device 5 of the present embodiment is applied, the steam pressure at the steam consumption facility inlet is increased by increasing the drum steam pressure to P ₀ ′ based on the measurement result of the steam consumption facility inlet steam pressure. It is possible to maintain the steam quality with P ′.

  In this embodiment, a cogeneration system using a gas turbine and a boiler is used as a means for generating steam. However, the solar heat pipe heat insulating device of the present invention is also used in a coal-fired boiler that obtains steam by burning pulverized coal inside the boiler. Applicable. Similarly, the present invention can be applied to an oil-fired boiler that obtains steam by burning oil inside the boiler, or a boiler plant that obtains steam by burning biomass or garbage.

  Moreover, although the solar heat pipe heat insulation apparatus described in the present embodiment uses the heat energy from the sun in the heat collector to heat the steam pipe, the solar heat conversion apparatus converts the light energy from the sun into electric power in this apparatus. A photovoltaic device may also be provided. When the power consumed by the solar power generator and the driving device for adjusting the elevation angle of the heat collector and the solar heat pipe heat insulation device control means is supplied by the solar power generation device, the solar heat pipe heat insulation device of the present invention is It can be installed regardless of the power source. In this case, it is possible to further improve the steam quality by installing the solar heat pipe heat retaining device at a position where the temperature drop in the pipe is remarkable.

  According to the present embodiment described above, the medium is heated using the heat energy from the sun obtained by the heat collector, and the heat energy of the medium is transmitted to the pipe, thereby converting the energy such as steam and electric power into energy. Without relying on, it is possible to obtain the effect of heat retention or heating of the fluid in the piping, and to reduce heat loss. As a result, higher temperature steam can be obtained at the entrance of the steam consumption facility, so that the operating rate and energy utilization rate in the steam consumption facility are improved, and the energy utilization rate of the entire system is improved.

  Furthermore, in the solar heat pipe heat insulation device of the present embodiment, by making the heater for keeping or heating the steam pipe detachable from the pipe, even when the pipe route is changed, it is not considered to secure the heat source. This makes it easy to keep the steam piping warm or warm.

  In addition, the heater can be installed even on the piping where the heater could not be installed so far, and the energy utilization rate of the entire system is improved.

  Furthermore, in the solar heat pipe heat insulating device of the present embodiment, the temperature of the steam at the entrance of the steam consuming facility is measured, and the solar altitude changes with time by controlling the angle of the collector based on this measured value and the solar altitude. Even in this case, the temperature of the medium to be heated can be maximized, and the steam pipe can be kept warm or heated throughout the day.

  Furthermore, by measuring the steam pressure at the inlet of the steam consuming equipment and controlling the opening of the pressure regulating valve installed at the boiler outlet based on this measured value, the steam consumption can be changed even when the piping route is changed. The steam pressure at the entrance of the facility is maintained, and the generation of drain due to a drop in steam pressure is minimized to improve the energy utilization rate of the entire system.

  The present invention can be used in a steam supply plant, particularly a cogeneration plant that supplies steam to a distant place using steam piping.

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Boiler 3 Steam piping 4 Pressure control valve 5 Solar heat insulation apparatus 6 Heat collector 7 Heater 8 Circulation pump 9 Steam consumption equipment 10 Solar heat insulation apparatus control means 11 Boiler control means 12 Boiler steam pressure measurement means 13 Boiler steam Pressure 14 Steam consumption facility inlet steam pressure measurement means 15 Steam consumption facility inlet steam pressure 16 Steam consumption facility inlet steam temperature measurement means 17 Steam consumption facility inlet steam temperature 18 Collector angle command 19 Pressure adjustment valve opening command 20 Solar altitude measurement Unit 21 Solar altitude 22 Heat transfer tube 23, 24 Flexible pipe

Claims (6)

In a steam supply plant equipped with a steam generating steam and steam piping for supplying steam generated by the boiler to steam consuming equipment,
A heat collector that collects solar heat to heat the medium, a heater that retains or heats the steam pipe using the medium heated by the heat collector, and a medium that passes through the heater is returned to the heat collector. comprising a solar heat pipe insulation system and a circulation pump for,
The heater has a plurality of heating tubes and a flexible pipe connected to each of the plurality of heating tubes, and is detachable by winding the flexible pipe in a circumferential direction of the steam pipe. And steam supply plant. The steam supply plant according to claim 1 ,
Steam temperature measuring means for measuring the steam temperature at the inlet of the steam consuming equipment;
Solar heat pipe heat retaining device control means for inputting solar altitude information and the steam temperature measured by the steam temperature measuring means, and controlling the angle of the heat collector so that the inlet steam temperature of the steam consuming equipment becomes a predetermined temperature. A steam supply plant comprising: The steam supply plant according to claim 1 ,
A pressure control valve for controlling the steam pressure at the boiler outlet;
Steam pressure measuring means for measuring the steam pressure at the inlet of the steam consuming equipment;
Boiler control means for inputting the steam temperature measured by the steam pressure measuring means and controlling the opening of the pressure control valve so that the steam pressure at the inlet of the steam consuming equipment becomes a predetermined pressure is provided. A featured steam supply plant. The steam supply plant according to claim 1,
The boiler is an exhaust heat recovery boiler of an internal combustion engine, a coal fired boiler that burns pulverized coal inside the boiler, an oil fired boiler that uses oil fuel, a biomass boiler that uses biomass fuel, or an incinerator that uses the exhaust heat of an incinerator A steam supply plant characterized by being a boiler. The steam supply plant according to claim 1,
It has a gas turbine that obtains electric power by its rotational drive, uses a waste heat recovery boiler that recovers exhaust heat of the gas turbine and generates steam as the boiler, and applies it to a cogeneration system that supplies electric power and heat A featured steam supply plant. A solar heat pipe heat retaining device that heats or heats the steam in a steam pipe that supplies steam generated by a boiler to steam consuming equipment using solar thermal energy ,
A collector that collects solar heat to heat the medium;
A heater for keeping or heating the steam pipe using a medium heated by the heat collector;
A circulation pump for refluxing the medium passing through the heater to the heat collector,
The heater has a plurality of heating tubes and a flexible pipe connected to each of the plurality of heating tubes, and is detachable by winding the flexible pipe in a circumferential direction of the steam pipe. Solar heat pipe insulation device.