JP2008280857A - Heat and cold simultaneous generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat and cold simultaneous generation system improved in steam utilization efficiency, which obtains heat and cold simultaneously. <P>SOLUTION: The heat and cold simultaneous generation system has a boiler, a superheater, a steam turbine, and an expander. The system is provided with a compressor for the superheater and a compressor for the boiler, both driven by the power generated by the steam turbine and expander. The superheater heats steam generated by the boiler by causing the combustor for superheater to burn the air supplied from the compressor for superheater and the fuel for superheater; the combustor for boiler introduces combustion gas from the superheater and air supplied from the compressor for boiler and burns them with the fuel for boiler, thereby causing the boiler to generate steam; and the above superheater heats the steam. The heated steam is led to the steam turbine to drive the steam turbine and the exhaust gas emitted from the boiler is led to the expander to drive the expander. The steam emitted from the steam turbine and the gas emitted from the expander are made available as the heat and cold, respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a simultaneous hot / cold heat generation system that is convenient in the field such as a food factory where heat and cold are used at the same time, and more particularly, to a simultaneous hot / cold heat generation system capable of generating an amount of heat that is greater than the input fuel.

  Conventionally, it is known that steam is generated by a small once-through boiler, and the steam is used in a steam utilization facility. For example, in a food factory or the like, low-pressure steam of about 0.3 MPa generated by a small once-through boiler is used in a steam pot or the like. Patent Documents 1 and 2 disclose a combined heat and power system including a micro gas turbine and a small once-through boiler. The small once-through boilers of Patent Documents 1 and 2 burn fuel with exhaust gas from a micro gas turbine that generates power, and supply steam generated by the small once-through boiler to steam utilization equipment through a steam supply path. I am doing so.

Further, in order to improve the utilization efficiency of the steam generated in the small once-through boiler, boiler means constituted by the small once-through boiler, a steam superheater that superheats the steam generated in the small once-through boiler, and the steam superheater A steam turbine driven by superheated superheated steam, and a power generation system that includes a generator that generates electric power as the steam turbine is driven. A cogeneration system configured as described above is known (see Patent Document 3).
JP 2004-108150 A JP 2004-108274 A JP 2006-329119 A

In the inventions described in Patent Documents 1 and 2, steam is generated by a small once-through boiler using the exhaust gas of a micro gas turbine, and the steam is used by a steam utilization facility. However, in this invention, the room which can improve further the utilization efficiency of the steam produced | generated with the small once-through boiler remains. In addition, since the small once-through boiler can be used at a gauge pressure of 1.0 MPa or less, there is room for further improving the steam utilization efficiency when using steam at a low pressure of about 0.3 MPa.
Moreover, in invention of patent document 3, since it is made to generate electric power using the steam produced | generated by the small once-through boiler before using with a steam utilization equipment, utilization of the steam produced | generated by the small once-through boiler is used. Although efficiency can be improved, it is not possible to obtain more power and heat than the amount of heat supplied.

  Accordingly, the present invention has been made in view of the above points, and the object of the present invention is to improve the efficiency of steam utilization and to simultaneously obtain hot and cold heat that can simultaneously obtain hot and cold heat exceeding the amount of heat supplied. It aims to provide a generation system.

[Principle] The principle of the present invention is as follows.
(1) A substantially high thermal efficiency is realized by mixing the exhaust gas emitted from the superheater that heats the steam supplied to the steam turbine into the intake air of the boiler combustor.
(2) Combustion for the superheater and boiler by compressing the air supplied to the combustor for the superheater and the boiler combustor using the power generated from the steam turbine and the expander, and then compressing and combusting. The amount of heat that is greater than the calorific value of the fuel that is put into the container can be extracted.
(3) The exhaust gas of the combustor for the superheater and the combustor for the boiler is guided to the expander, supplementing the driving power of the compressor, and simultaneously supplying cold heat.

[Means] To achieve the above object, a system for simultaneously generating heat and cold according to the present invention comprises a boiler for generating steam, a superheater for heating steam from the boiler, a steam turbine driven by the heated steam, and a boiler Provided with an expander driven by exhaust gas discharged from the superheater compressor and boiler compressor driven by power generated by the steam turbine and the expander, and supplied from the superheater compressor And the superheater fuel are combusted in the superheater combustor to heat the steam generated in the boiler in the superheater, and the combustion gas from the superheater and the air supplied from the boiler compressor are Steam is generated in the boiler by being guided to the boiler combustor and is burned with the fuel for the boiler, and the steam is heated by the superheater and led to the steam turbine. Drives exhaust gas discharged from the boiler to the expander and drives the expander, and steam discharged from the steam turbine can be used as hot heat, and gas discharged from the expander can be used as cold heat It is characterized by that.

The present invention has the following excellent effects.
(1) By mixing exhaust gas from the superheater before the steam turbine into the intake air of the boiler combustor, waste heat from the superheater is not wasted and efficiently used, and the overall loss is reduced.
(2) By compressing the intake air in front of the combustor for the superheater and the combustor for the boiler, it is possible to bring about the same effect as the heat pump. Heat can be generated in excess of efficiency that was previously unacceptable in size. With regard to the power of this compressor, the pressure energy of each exhaust gas of the superheater and the boiler is recovered by an expander, and by recovering the power from the micro steam turbine, the compressor power is increased from 10 compared with a conventional 95% efficiency boiler. The efficiency can be improved by 20%, and at the same time, cold heat can be generated.
(3) It is possible to generate warm heat exceeding the calorific value of the fuel.
Usually, when steam is produced by combustion, it is difficult to greatly exceed 1 in view of the calorific value of the fuel. By utilizing the system according to the present invention, it is possible to produce a heat quantity exceeding 1 without extremely increasing the heat exchanger. This is very effective for energy saving.
(4) It is possible to simultaneously generate hot and cold heat required in a food factory or the like.

  The best mode of the simultaneous hot / cold heat generation system according to the present invention will be described in detail with reference to the drawings. In FIG. 1, numerical values indicating flow rate (t / h, kg / h), pressure (kPa), temperature (° C.), input / output (kW), etc. are numerical values when system calculation is performed as an example. .

FIG. 1 is a system diagram showing the overall configuration of a system for simultaneously generating heat and cold according to an embodiment of the present invention.
This simultaneous heat / cold heat generation system includes a steam passage 30 that communicates the water pump 13, the boiler 6, the superheater 1, the steam turbine 20, and the heat utilization equipment 21.
The steam passage 30 is a path for guiding the steam generated in the boiler 6 to the heat utilization facility 21 via the steam turbine 20, and includes a water pipe 22a, a first steam pipe 22b, a second steam pipe 22c, and a third pipe. A steam pipe 22d is provided. In addition, about the on-off valve suitably provided in piping, illustration is abbreviate | omitted.

The water pump 13 is designed so that, for example, 3 t / h of water 14 can be supplied to the boiler 6 at a pressure of 827 kPa. Moreover, the boiler 6 is comprised by one or several small once-through boiler, for example, and produces | generates the steam (saturated steam) 15 of temperature 167 degreeC and pressure 788 kPa. The small once-through boiler 6 is a once-through boiler with a working pressure of 1 MPa or less and a heat transfer area of 10 m ² or less, a high thermal efficiency of 95% or more, and a boiler engineer's license is not required. Introduced mainly in small and medium factories such as the textile industry. The use conditions of the steam generated by this small once-through boiler are used in a range where the flow rate is 2 t / h to 20 t / h and the pressure is 1 MPa.

  Saturated steam 15 generated in the boiler 6 is introduced into the superheater 1 installed on the downstream side of the boiler 6, heated by the heat of the superheater combustor 5 described later, and steam having a temperature of 218 ° C. and a pressure of 750 kPa Become.

The steam heated by the superheater 1 is introduced into the small steam turbine 20 through the second steam pipe 22c, and after driving the steam turbine 20, the steam becomes a steam having a temperature of 127 ° C. and a pressure of 250 kPa. Led to
The steam turbine 20 is configured such that steam enters the impeller from the circumferential direction, and is configured such that the steam exits in the axial direction, and performs heat generation of 136.5 kw with a heat insulation efficiency of 77%. Can do.

  The heat utilization facility 21 is configured to be able to heat, for example, room temperature clean water or steam food using steam introduced from the third steam pipe 22d.

  Further, this simultaneous heating / cooling system includes a superheater compressor 3, a superheater combustor 5, a heating gas passage 40 from the superheater 1 to the boiler combustor 8, a boiler compressor 11, and a boiler combustor. 8, a steam generation gas passage 50 communicating with the boiler 6, the gas-liquid separator 17, the expander 18, and the cold utilization facility 23 is provided.

  For example, the heated gas passage 40 compresses the air 2 having a pressure of 100 kPa, a temperature of 25 ° C., and a flow rate of 180.8 kg / h by the superheater compressor 3, and is compressed by compressed air and fuel having a temperature of 284.5 ° C. The methane gas 4 having a flow rate of 9.8 kg / h is combusted in the superheater combustor 5 and is supplied to the superheater 1 as a high-temperature gas of 2205 ° C. The saturated steam 15 generated in the boiler 6 in the superheater 1 is supplied. While heating, it introduce | transduces into the combustor 8 for boilers, becomes the heat source, and is provided with the air piping 40a, the 1st heating gas piping 40b, and the 2nd heating gas piping 40c.

The steam generating gas passage 50 is, for example, compressed air and fuel compressed at a temperature of 284.5 ° C. by compressing the air 10 having a pressure of 100 kPa, a temperature of 25 ° C., and a flow rate of 2800 kg / h by the boiler compressor 11. The methane gas 12 having a flow rate of 130 kg / h is combusted in the boiler combustor 8 and is supplied to the boiler 6 as a high-temperature gas of 1877 ° C., and is discharged from the boiler 6 as boiler exhaust gas 16 having a temperature of 46 ° C. After separating 278.9 kg / h of water by the gas-liquid separator 17, the water is introduced into the expander 18 composed of a gas turbine, a positive displacement prime mover, and the like, and after driving the expander 18, the outlet 19 of the expander 18. In this case, the temperature is lower than the outside air temperature, becomes a gas having a temperature of −14 ° C. and a flow rate of 2842 kg / h, can be used as cold heat, and is led to the cold heat utilization equipment 23. 0a, and it includes combustion gas pipe 50b, the first exhaust gas pipe 50c, the second exhaust pipe 50d and the third exhaust pipe 50e.
The expander 18 can generate 69.1 kw with 75% heat insulation efficiency.

  The total power output of the steam turbine 20 and the expander 18 is 205.6 kw, and using this electric power, the efficiency of the superheater 3 is 75%, the required power is 13.3 kw, the efficiency is 75%, and the required power is 185.5 kw. When the boiler compressor 11 is driven, 6.8 kw can be used as surplus power. This surplus power is used as power for auxiliary equipment in this system or for other purposes.

  As described above, the air 2 supplied to the superheater 1 is compressed by the superheater compressor 3, and is supplied to the methane gas 4 and the combustor 5 as fuel for the superheater in a state where the temperature and pressure are increased. The steam 15 discharged from the boiler 6 is heated by the superheater 1 in FIG. 1, and the combustor 5 and the superheater 1 are shown separately for convenience of explanation in FIG. , Superheat steam while burning. Thereafter, the superheater exhaust gas 7 discharged from the superheater 1 is supplied to the boiler combustor 8 as one of the heat sources for the boiler.

  Further, as described above, the air 10 supplied to the boiler 6 is compressed by the boiler compressor 11 and mixed with the superheater exhaust gas 7 in a state where the temperature and pressure are increased, or both are used for the boiler. It is supplied to the combustor 8. The boiler combustor 8 is also supplied with methane gas 12 as fuel for the boiler, and heats the water 14 supplied from the water pump 13 by combustion to generate saturated steam 15. In FIG. 1, for convenience of explanation, the boiler combustor 8 and the boiler 6 are written separately, but are actually integrated and generate steam while being burned. Further, the boiler exhaust gas 16 from the boiler 6 is usually used for feed water heating in a feed water heater installed in front of the pump 13 as necessary, as in a normal boiler, but in FIG. Omitted.

  In the present embodiment shown in FIG. 1, for the sake of convenience of calculating the calorific value, an example in which methane gas (CH4) is used as the superheater fuel and the boiler fuel is shown, but this is not restrictive, and a known fuel is used. It goes without saying that it can be done.

As described above, the simultaneous heating and cooling generation system according to the present embodiment can simultaneously generate heating and cooling. In the example shown in FIG. 1, the heat generated by the boiler fuel 12 and the superheater fuel 4 is generated. For the amount (LHV) 1943 KW, hot heat 2194 KW and cold heat 54.45 KW are generated. At this time, the total heat amount of the warm heat 2194 KW and the cold heat 54.45 KW can exceed the heat amount 1943 KW of the input fuel. In this example, it is about 1.1 times the amount of heat supplied.
In this way, it is possible to take out more heat than is put into the combustor. Moreover, the heat transfer area of a boiler can also be reduced by compressing the supplied air.

The system for simultaneously generating heat and cold according to the present embodiment compresses the air supplied to the superheater combustor and the boiler combustor, thereby extracting heat from the same effect as the heat pump, that is, high-temperature and high-pressure compressed air. Then, it is possible to bring about the effect that the power can be recovered using pressure, and by supplying the heat from the fuel to this, the heat exceeds the efficiency that could not be conventionally exceeded by the size of realistic heat exchange. Can be generated.
At that time, the power of the compressor is compared with the conventional 95% efficiency boiler by recovering the pressure energy of each exhaust of the heater and boiler by the expander and recovering the power from the steam turbine. Thus, the efficiency can be improved by 10 to 20%, and cold heat can be generated at the same time.

1 is a system diagram showing an overall configuration of a simultaneous heating / cooling system according to an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Superheater 2 Air 3 Superheater compressor 4 Methane gas 5 Superheater combustor 6 Boiler 7 Superheater exhaust gas 8 Boiler combustor 10 Air 11 Boiler compressor 12 Methane gas 13 Water pump 14 Water 15 Saturated steam 16 Boiler exhaust gas 17 Air Liquid separator 18 Expander 19 Expander outlet 20 Steam turbine 21 Thermal equipment 22a Water piping 22b First steam piping 22c Second steam piping 22d Third steam piping
23 Cold-use equipment 30 Steam passage 40 Heating gas passage 40a Air piping 40b First heating gas piping 40c Second heating gas piping 50 Steam generation gas passage 50a Air piping 50b Combustion gas pipe 50c First exhaust pipe 50d Second exhaust pipe 50e Third exhaust pipe

Claims (1)

  A steam generator, a superheater for heating steam from the boiler, a steam turbine driven by the heated steam, and an expander driven by exhaust gas discharged from the boiler, the steam turbine and the expander Provided with a compressor for a superheater and a compressor for a boiler that are driven by the power generated by the boiler, and in the superheater, the air supplied from the compressor for the superheater and the fuel for the superheater are burned in the combustor for the superheater. The steam generated in the above is heated, the combustion gas from the superheater and the air supplied from the boiler compressor are led to the boiler combustor to generate steam in the boiler by combustion with the boiler fuel, The steam is heated by the superheater and led to the steam turbine to drive the steam turbine, and exhaust gas discharged from the boiler is led to the expander and expanded. Drives machine, the as heat the steam discharged from the steam turbine, also heat-cold concurrent system, characterized in that the available gas discharged from the expander as cold.

Images