JP4555784B2 - Steam generating apparatus using low-temperature waste heat, thermoelectric supply apparatus using the apparatus, and steam generating method - Google Patents

Description

The present invention, steam generation equipment using low-temperature waste heat, cogeneration apparatus using the device of that, and a steam generation process.

  In recent years, in order to make effective use of energy, attempts have been made to effectively use waste heat that has been discarded as it is, and various examples of thermoelectric supply devices that use an internal combustion engine to supply electric power and heat are various. Proposed.

  For example, in Patent Document 1, electric power and heat are generated by generating electric power with a generator connected to an internal combustion engine and supplying cooling water that has recovered waste heat of the internal combustion engine to a heat load such as a hot water supply tank as it is. Is described.

JP 2003-21393 A

  However, Patent Document 1 does not consider generation of water vapor that can be effectively used as thermal energy. That is, since the temperature of the cooling water that recovered the waste heat of the internal combustion engine is, for example, 80 ° C. to 90 ° C., it is generally difficult to generate water vapor with the waste heat. However, in food processing plants, paper mills, and the like, steam is often used as thermal energy. Therefore, if steam can be generated instead of warm water by the waste heat of the internal combustion engine that drives the generator, it can be effectively used. Similarly, it is desired to generate heat by steam using low-temperature waste heat generated in the plant or low-temperature waste heat such as river water.

An object of the present invention and this generating effective available steam by utilizing the low-temperature waste heat.

In order to solve the above problems, a steam generator of the present invention includes an evaporator that evaporates water using low-temperature waste heat as a heat source, and a compressor that compresses water vapor evaporated by the evaporator, and the rotation speed of the compressor is increased. The control means for changing, the valve provided in the flow path for supplying water to the evaporator, and the control means for adjusting the valve opening of the valve , the rotation of the compressor corresponding to the temperature of the low-temperature waste heat The internal pressure of the evaporator is controlled by controlling the number and the valve opening degree of the valve .

  That is, with such a configuration, even if the heat source is at a low temperature, the pressure in the evaporator is adjusted to the vacuum side according to the temperature, and the water supplied to the evaporator is evaporated at a low temperature. Can be made. Then, by compressing the water vapor evaporated in the evaporator with a compressor, desired high-temperature and high-pressure water vapor can be generated. Therefore, high-temperature and high-pressure steam that can be effectively used by low-temperature waste heat can be generated.

In this case, the compressor is a multistage compressor in which a plurality of compressors are connected in series, and the steam compressed by each compressor is saturated steam between the compressors of the multistage compressor. It is desirable to provide cooling means for cooling.

  That is, when high-pressure water vapor is desired, if the water vapor is compressed to a desired pressure with a single compressor, the water vapor becomes too high, which may restrict the selection of the material for the compressor. Therefore, the temperature of the water vapor can be prevented from becoming too high by compressing the water vapor evaporated by the evaporator in stages while cooling with the cooling means provided between the compressors of the plurality of compressors. . That is, it is possible to generate water vapor at a desired pressure while suppressing the temperature, and to maintain the reliability of each compressor.

  In this case, as the cooling means, it is desirable to use means for injecting water into water vapor between the compressors. Thereby, since the injected water is preserve | saved as internal energy of water vapor | steam, thermal efficiency can be improved.

The thermoelectric supply device of the present invention flows through an internal combustion engine, a generator that is driven by the internal combustion engine and supplies power to a power load, a cooling water supply unit that supplies cooling water to the internal combustion engine, and a cooling water supply unit An evaporator that evaporates water using the cooling water as a heat source, a compressor that compresses water vapor evaporated by the evaporator and supplies the heat load to a heat load, a control means for changing the rotation speed of the compressor, and water in the evaporator And a control means for adjusting the valve opening degree of the valve, and the compressor is driven by part or all of the electricity generated by the generator , and the temperature of the low-temperature waste heat by controlling the valve opening degree of the rotational speed and the valve of the compressor in response characterized that you control the internal pressure of the evaporator.

  That is, the heat source of the evaporator uses, for example, 80 ° C. to 90 ° C. because it uses the cooling water from which the waste heat of the internal combustion engine is recovered. According to this configuration, the pressure in the evaporator corresponds to the temperature of the heat source. Can be adjusted to the vacuum side, and the water supplied to the evaporator can be evaporated at the temperature of the cooling water. Moreover, the desired high-temperature and high-pressure steam can be generated by compressing the water vapor evaporated in the evaporator with a compressor. Furthermore, electric power can be generated by a generator driven by an internal combustion engine. Therefore, it is possible to generate high-temperature and high-pressure steam that can be effectively used by using low-temperature waste heat and supply it to the heat load, and to supply power to the power load.

Even in this case, the compressor is a multi-stage compressor in which a plurality of compressors are connected in series, and the steam compressed by each compressor is saturated between each compressor of the multi-stage compressor. it is desirable comprising a cooling means for cooling the.

The thermoelectric supply device also includes an internal combustion engine, a generator that is driven by the internal combustion engine and supplies electric power to an electric power load, cooling water supply means that supplies cooling water to the internal combustion engine, and cooling water that flows through the cooling water supply means. A first evaporator that evaporates water as a heat source, a second evaporator that evaporates water using low-temperature waste heat other than cooling water as a heat source, and compresses water vapor evaporated in the first evaporator to heat load a first compressor for supplying, to compress the water vapor evaporated in the second evaporator and a second compressor supplied to the heat load, low-temperature waste heat other than the cooling water, the third compressor A refrigerant of a refrigeration cycle formed including a second evaporator acting as a condenser, a throttle valve, and a third evaporator, and a first compressor, a second compressor, and The third compressor is preferably driven by part or all of the electricity generated by the generator. Yes.

  According to this, since the second evaporator and the second compressor can generate high-temperature and high-pressure steam that can be effectively used by using low-temperature waste heat other than the waste heat of the internal combustion engine, The amount of water vapor that can be supplied to can be increased.

  In this case, of the first compressor and the second compressor, the discharge side of a compressor that compresses water vapor evaporated by a heat source having a lower temperature (hereinafter referred to as a low-temperature heat source compressor) is It is preferably connected to the suction side of the other compressor.

  In other words, it is better to compress the steam generated in the compressor on the low-temperature heat source side to the same pressure as the steam generated in the other compressor to the suction side pressure of the other compressor. The pressure ratio of the compressor (the value obtained by dividing the pressure on the discharge side by the pressure on the suction side) can be reduced. Therefore, the power consumption of the compressor on the low-temperature heat source side can be reduced, and as a result, the overall power consumption of both compressors can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the apparatus which generate | occur | produces the water vapor | steam which can be utilized effectively using low-temperature waste heat, and the thermoelectric supply apparatus using the apparatus are realizable.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a water vapor generating apparatus to which the present invention is applied and a thermoelectric supply apparatus using the apparatus will be described with reference to FIGS. In the following description, the same functional parts are denoted by the same reference numerals, and redundant description is omitted.

  In FIG. 1, the structure of the thermoelectric supply apparatus of Example 1 comprised by applying the steam generator of one Example of this invention is shown. As shown in FIG. 1, the thermoelectric supply device 1 includes an internal combustion engine 2, a generator 3 that is driven by the internal combustion engine 2 to generate electric power, a cooling water circulation pump 4 that supplies cooling water to the internal combustion engine 2, an internal combustion engine An evaporator 5a that evaporates water using the cooling water supplied to the engine 2 as a heat source, a compressor 6a that compresses water vapor evaporated by the evaporator 5a, and a motor 7a that drives the compressor 6a.

  Next, operation | movement of the thermoelectric supply apparatus 1 of a present Example is demonstrated. The supply water 9 supplied to the evaporator 5a is heated and evaporated by the cooling water 10 that is circulated through the cooling water jacket by the cooling water circulation pump 4 and recovered the waste heat of the internal combustion engine 2. The evaporated water vapor is sucked into the compressor 6a and compressed to become a desired high-pressure / high-temperature water vapor 11, which is supplied to the water vapor utilization facility.

  Further, the motor 7a for driving the compressor 6a is driven by using a part or all 13 of the electric power 12 generated by the generator 3, and uses electric power except for the electric power used for driving the compressor 6a. Supplied to the facility.

  According to the thermoelectric supply device 1 of the present embodiment, it is possible to supply water vapor that can be effectively used to the steam utilization facility using the waste heat of the internal combustion engine 2 and to supply power to the power utilization facility. it can.

  Here, even if the cooling water 10 that recovered the waste heat of the internal combustion engine 2 serving as the heat source of the evaporator 5a is less than 100 ° C. that evaporates water at atmospheric pressure, the inside of the evaporator 5a is the heat source. Since the pressure is adjusted to a pressure equal to or lower than the atmospheric pressure that can evaporate water according to the temperature, the supply water 9 can be evaporated. The means for adjusting the pressure inside the evaporator 5a is, for example, providing a throttle valve in a pipe for supplying the supply water 9 to the evaporator 5a to adjust the valve opening, or adjusting the rotational speed of the compressor 6a. Etc.

  Further, as described above, the present embodiment is configured by applying the water vapor generating apparatus according to one embodiment of the present invention. That is, the steam generator in the present embodiment has an evaporator 5a that evaporates water using low-temperature waste heat (in this embodiment, the cooling water 10 that recovered the waste heat of the internal combustion engine 2) as a heat source, and the evaporator 5a evaporates. The compressor 6a that compresses the generated steam to generate desired high-temperature and high-pressure steam, and a motor 7a that drives the compressor 6a.

  In FIG. 2, the structure of the thermoelectric supply apparatus in Example 2 of this invention is shown. The heat source supply device of the present embodiment adds a system for generating high-temperature and high-pressure steam to the thermoelectric supply device 1 of the first embodiment using low-temperature waste heat other than the cooling water 10 that recovered the waste heat of the internal combustion engine 2 as a heat source. Therefore, the description of the same parts as those in the first embodiment is omitted.

  As shown in FIG. 2, the thermoelectric supply device 1 compresses the thermoelectric supply device 1 according to the first embodiment with an evaporator 5b that evaporates water using the low-temperature waste heat 15 as a heat source, and a water vapor that is evaporated by the evaporator 5b. A machine 6b and a motor 7b for driving the compressor 6b are added. Further, the evaporator 5b is supplied with the supply water 9 similarly to the evaporator 5a, and the steam compressed by the compressor 6b is supplied to the steam utilization facility together with the steam compressed by the compressor 6a. Has been. Further, a part or all 13 of the electric power 12 generated by the generator 3 is supplied to the motor 7b as in the motor 7a.

  Next, operation | movement of the thermoelectric supply apparatus 1 of a present Example is demonstrated. The supply water 9 supplied to the evaporator 5b is heated by the low-temperature waste heat 15 supplied to the evaporator 5b to evaporate. The evaporated water vapor is sucked into the compressor 6b and compressed to become a desired high-pressure / high-temperature water vapor 11, which is supplied to the water vapor utilization facility.

  Here, the low-temperature waste heat 15 may be anything that can be used as a heat source for the evaporator 5b, such as low-temperature waste heat generated in a plant or river water.

  According to the thermoelectric supply device 1 of the present embodiment, since the low-temperature waste heat 15 other than the cooling water 10 that recovered the waste heat of the internal combustion engine 2 can also be used for steam generation, the amount of steam that can be supplied to the steam utilization facility is reduced. Can be increased.

  In FIG. 3, the structure of the thermoelectric supply apparatus in Example 3 of this invention is shown. Since the thermoelectric supply device of the present embodiment is different only in the connection side on the discharge side of the compressor 6b in the thermoelectric supply device 1 of the second embodiment, the description of the portions overlapping with those of the second embodiment is omitted.

  In this embodiment, the temperature of the low-temperature waste heat 15 serving as the heat source of the evaporator 5b is lower than the cooling water 10 that recovered the waste heat of the internal combustion engine 2 serving as the heat source of the evaporator 5a. As shown in FIG. 3, the discharge side of the compressor 6b is connected to the suction side of the compressor 6a.

  According to the thermoelectric supply device 1 of the present embodiment, the compressor 6b only needs to compress the water vapor to the pressure on the suction side of the compressor 6a, so the pressure ratio of the compressor 6b (on the discharge side) compared to the second embodiment. The value obtained by dividing the pressure by the pressure on the suction side) can be reduced. Therefore, the power consumption of the compressor 6b can be reduced, and as a result, the total power consumption of the compressor 6a and the compressor 6b can be reduced.

  Here, in the present embodiment, the case where the temperature of the heat source of the evaporator 5b is lower than the heat source of the evaporator 5a is illustrated, but when the magnitude relation of the temperature of the heat source is opposite, the discharge side of the compressor 6a is compressed. What is necessary is just to supply the water vapor | steam compressed by the compressor 6b to the water vapor | steam utilization equipment by connecting with the suction side of the machine 6b.

  In FIG. 4, the structure of the thermoelectric supply apparatus in Example 4 of this invention is shown. The thermoelectric supply device of the present embodiment is different from the third embodiment only in that the compressor 6a and the compressor 6b of the thermoelectric supply device 1 in the third embodiment are configured as multistage compressors and perform intermediate cooling. Description of overlapping parts is omitted.

  As shown in FIG. 4, the compressor 6a includes a compressor 6a-1 and a compressor 6a-2 connected in series, and the compressor 6b includes a compressor 6b-1 and a compressor connected in series. 6b-2. An injection nozzle 16 is provided between the compressors, and the injection nozzle 16 and the supply water 9 are connected via an injection pump 17.

  Next, the operation of this embodiment will be described. The supply water 9 supplied to the evaporator 5b evaporates in the evaporator 5b and is sucked into the compressor 6b-2 and compressed. The water vapor compressed by the compressor 6b-2 is pressurized by the injection pump 17 and cooled by water sprayed by the injection nozzle 16, and is then sucked into the compressor 6b-1 and further compressed. The water vapor compressed by the compressor 6b-1 is similarly cooled and then sucked into the compressor 6a-2 together with the water vapor evaporated by the evaporator 5a and further compressed. Then, the water vapor compressed by the compressor 6a-2 is cooled in the same manner, and then sucked into the compressor 6a-1 and further compressed to become the desired high-temperature / high-pressure water vapor 11 and supplied to the water vapor utilization facility. The

  Next, the effect of the multistage compressor and the intermediate cooling of the present embodiment will be described with reference to FIG. FIG. 5 is a so-called Ts diagram showing the state of water vapor using temperature and specific entropy. The curve from the vertical axis of 360 ° C. to the horizontal axis of 9.2 kJ / kg · K is a saturated vapor line, the region above this line is superheated steam, and the region below is a gas-liquid two-phase state. Further, after extending from the upper right to the lower left and intersecting the saturated vapor line, the line extending horizontally to the left in the two-phase region is an isobaric line and coincides with the isotherm in the two-phase region. Here, the case where the saturated steam A of 60 ° C. and 20 kPa is compressed to 600 kPa to generate saturated steam of 159 ° C. will be described as an example. The heat insulation efficiency of the compressor is 100%. When the saturated steam in state A is compressed to 600 kPa in one step, state B is obtained, and the water vapor temperature on the discharge side becomes 466 ° C. Since the necessary steam temperature is 159 ° C., the compressor driving power is wasted, and the reliability of the compressor is also reduced due to the high temperature. On the other hand, if this is compressed stepwise up to 600 kPa at each stage pressure ratio of 2.34 while performing intermediate cooling, it becomes a state C where the steam temperature on the discharge side is 217 ° C., and the driving power of the compressor can be reduced and the reliability can be improved. As an intermediate cooling method, an intercooler or the like can be used in addition to liquid injection.

  In FIG. 6, the structure of the thermoelectric supply apparatus in Example 5 of this invention is shown. Since the thermoelectric supply device of the present embodiment is different only in the heat source of the evaporator 5b in the thermoelectric supply device 1 of the fourth embodiment, the description of the parts overlapping with those of the fourth embodiment is omitted.

  As shown in FIG. 6, the refrigerant 21 of the refrigeration cycle formed by the evaporator 5b, the throttle valve 20, the evaporator 5c, and the compressor 6c is used as the heat source of the evaporator 5b. Further, the evaporator 5 c is circulated and connected to the building via the cold water circulation pump 22.

  Here, the refrigerant | coolant 21 used as the heat source of the evaporator 5b is HFC134a etc. which do not solidify even if it is 0 degrees C or less, for example. The refrigerant 21 is evaporated by the evaporator 5c using the return cold water 23 of about 12 ° C. used for cooling the building as a heat source, and is sucked into the compressor 6c driven by the motor 7c. The refrigerant 21 compressed into the superheated gas by the compressor 6c gives heat to the supply water 9 supplied to the evaporator 5b and is cooled and condensed and liquefied. Then, after the pressure is reduced by the throttle valve 20, the flow returns to the evaporator 5c. The return cold water 23 used for cooling the building is cooled to about 7 ° C. by the evaporator 5 c and returned to the building by the cold water circulation pump 22.

  According to the thermoelectric supply device 1 of the present embodiment, high-temperature and high-pressure steam can be generated using waste heat at a lower temperature than that of the fourth embodiment as a heat source.

  In FIG. 7, the structure of the thermoelectric supply apparatus in Example 6 of this invention is shown. Since the thermoelectric supply device of the present embodiment is different only in the heat source of the evaporator 5c in the fifth embodiment, the description of the parts overlapping with the fifth embodiment is omitted.

  As shown in FIG. 7, the heat source of the evaporator 5 c is an antifreeze liquid 26 that recovers heat from the atmosphere by the heating tower 24 and is supplied to the evaporator 5 c by the circulation pump 25. The temperature of the antifreeze liquid 26 is about 32 ° C. in summer and about −7 ° C. in winter.

  According to the thermoelectric supply device 1 of the present embodiment, for example, even when there is no waste heat such as low-temperature waste heat or river water generated in the plant, or even when there is no building, by recovering and using heat from the ambient air High temperature and high pressure water vapor can be generated.

  In FIG. 8, the structure of the thermoelectric supply apparatus in Example 7 of this invention is shown. Since the thermoelectric supply device of the present embodiment is obtained by adding an exhaust gas boiler to the thermoelectric supply device 1 of the sixth embodiment, the description of the portions overlapping with those of the sixth embodiment is omitted.

  As shown in FIG. 8, an exhaust gas boiler 27 is provided together with the thermoelectric supply device 1 of the sixth embodiment, and the supply water 9 supplied to the exhaust gas boiler 27 evaporates using the exhaust gas 28 of the internal combustion engine 2 as a heat source. , Supplied to steam utilization equipment.

  According to the thermoelectric supply device 1 of this embodiment, in addition to the waste heat of the internal combustion engine 2 and other low-temperature waste heat, the heat of the exhaust gas 28 of the internal combustion engine 2 can also be used for the generation of water vapor. The amount of water vapor supplied can be further increased.

It is a figure which shows the structure of the thermoelectric supply apparatus in Example 1 of this invention. It is a figure which shows the structure of the thermoelectric supply apparatus in Example 2 of this invention. It is a figure which shows the structure of the thermoelectric supply apparatus in Example 3 of this invention. It is a figure which shows the structure of the thermoelectric supply apparatus in Example 4 of this invention. It is a Ts diagram of water vapor explaining the effect of multistage compression and intermediate cooling of the present invention. It is a figure which shows the structure of the thermoelectric supply apparatus in Example 5 of this invention. It is a figure which shows the structure of the thermoelectric supply apparatus in Example 6 of this invention. It is a figure which shows the structure of the thermoelectric supply apparatus in Example 7 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thermoelectric supply device 2 Internal combustion engine 3 Generator 4 Cooling water circulation pump 5 Evaporator 6 Compressor 7 Motor 9 Supply water 10 Cooling water 11 Water vapor 16 Injection nozzle 17 Injection pump 27 Exhaust gas boiler

Claims (8)

In a steam generator comprising: an evaporator that evaporates water using low-temperature waste heat as a heat source; and a compressor that compresses water vapor evaporated in the evaporator,
Control means for changing the rotational speed of the compressor;
A valve provided in a flow path for supplying water to the evaporator;
Control means for adjusting the valve opening of the valve ,
A steam generator characterized in that the internal pressure of the evaporator is controlled by controlling the rotational speed of the compressor and the valve opening of the valve in accordance with the temperature of the low-temperature waste heat .   The compressor is a multi-stage compressor in which a plurality of compressors are connected in series, and the steam compressed by each of the compressors becomes saturated steam between the compressors of the multi-stage compressor. The steam generator according to claim 1, further comprising a cooling means for cooling. An internal combustion engine, a generator that is driven by the internal combustion engine and supplies power to an electric power load, a cooling water supply means that supplies cooling water to the internal combustion engine, and water that uses the cooling water flowing through the cooling water supply means as a heat source An evaporator for evaporating, a compressor for compressing water vapor evaporated in the evaporator and supplying it to a heat load, a control means for changing the rotational speed of the compressor, and a flow for supplying water to the evaporator A valve provided on the passage, and a control means for adjusting the valve opening of the valve, wherein the compressor is driven by part or all of the electricity generated by the generator, and the temperature of the low-temperature waste heat The thermoelectric supply device which controls the internal pressure of the evaporator by controlling the rotation speed of the compressor and the valve opening degree of the valve correspondingly .   The compressor is a multi-stage compressor in which a plurality of compressors are connected in series, and the steam compressed by each of the compressors becomes saturated steam between the compressors of the multi-stage compressor. The thermoelectric supply device according to claim 3, further comprising cooling means for cooling.   An internal combustion engine, a generator that is driven by the internal combustion engine and supplies power to an electric power load, a cooling water supply means that supplies cooling water to the internal combustion engine, and water that uses the cooling water flowing through the cooling water supply means as a heat source A first evaporator to be evaporated, a second evaporator to evaporate water using low-temperature waste heat other than the cooling water as a heat source, and water vapor evaporated by the first evaporator is compressed and supplied to a heat load A first compressor, and a second compressor that compresses the water vapor evaporated by the second evaporator and supplies the compressed heat to a heat load. The low-temperature waste heat other than the cooling water is a third compressor. And a refrigerant of a refrigeration cycle formed including the second evaporator acting as a condenser, a throttle valve, and a third evaporator, the first compressor, the second compression And the third compressor is a part or all of the electricity generated by the generator. Driven thermoelectric supply device.   Of the first compressor and the second compressor, a discharge side of a compressor that compresses water vapor evaporated by a heat source having a lower temperature is connected to a suction side of the other compressor. The thermoelectric supply device according to claim 5.   Each of the first compressor and the second compressor is a multistage compressor in which a plurality of compressors are connected in series, and each compressor is interposed between the compressors of the multistage compressor. The thermoelectric supply device according to claim 6, further comprising a cooling unit that cools the compressed water vapor so as to become saturated steam. In a method of generating water vapor using a water vapor generator comprising an evaporator that evaporates water using low-temperature waste heat as a heat source, and a compressor that compresses water vapor evaporated in the evaporator,
Control means for changing the rotational speed of the compressor;
And a control means for adjusting a valve opening degree of a valve provided in a flow path for supplying water to the evaporator,
A steam generation method that generates steam by controlling the internal pressure of the evaporator according to the temperature of the low-temperature waste heat.

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