JP2015017599A - Lower order thermal energy recovery method and lower order thermal power generating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lower order thermal energy recovery method and a lower order thermal power generating system in which not-yet utilized lower order thermal energy can be recovered with a high coefficient of performance (COP).SOLUTION: Refrigerant vapor is generated by a lower order thermal energy source Es through a lower order thermal recovery heat exchanger EVo, it is compressed by a refrigerant compressor P2 to generate high temperature high pressure refrigerant, heat of the high temperature high pressure refrigerant is radiated to working fluid of an airtight power cycle 15 and at the same time high pressure refrigerant is generated, the high pressure refrigerant is reduced in its pressure and expanded by the first expander 40A to recover the first mechanical energy. In addition, the stored power is supplied to the pulse power source 28 to generate pulse power. A high enthalpy converter 42 is electrically energized with the pulse power to heat up to a prescribed temperature higher than a heat receiving temperature of the working fluid, the high temperature and high pressure working fluid is contacted with the high enthalpy converter 42 to generate high enthalpy power fluid and recover the second mechanical energy while expanding the high enthalpy power force fluid by the second expander 40B.

Description

  The present invention relates to a lower thermal energy recovery method and a lower thermal power generation system, and more particularly to a lower thermal energy recovery method and a lower thermal power generation system using natural energy.

  In recent years, large-scale damage caused by heat waves, floods, tornadoes, etc. has occurred frequently on a global scale due to climate change due to global warming, and urgent countermeasures have become an issue. As a solution, effective use of low-level heat energy such as atmospheric heat, underground heat, soil heat, etc. existing in a huge amount on the earth has been attracting attention.

  Patent Document 1 obtained by using a lower heat recovery heat exchanger to evaporate the working fluid of the sealed power cycle with a lower heat energy medium, while heating the working fluid vapor with a high-temperature gas generated by a heat pump. A low thermal energy recovery method and a plant have been proposed in which superheated steam is expanded into power by being expanded in a turbine, and the expansion gas of the turbine is cooled by cold generated by a heat pump.

  In Patent Document 2, steam is generated by heating a boiler liquid using low thermal energy such as outside air heat at a first altitude position, and the steam is condensed by a cooler at a second altitude position. Has been proposed, and the liquid is dropped to the turbine to drive the turbine to generate power.

U.S. Pat. No. 4,292,809 US Pat. No. 5,488,828

  By the way, in the low thermal energy recovery method and plant disclosed in Patent Document 1, the temperature of the high-temperature gas obtained by the heat pump is about 110 to 130 ° C., and therefore it is impossible to supply a high enthalpy working fluid to the turbine. There was no practical mechanical energy output. In addition, since the heat of the high-temperature and high-pressure refrigerant generated by the heat pump is not used effectively and is discarded in the lower heat source, the lower heat recovery efficiency cannot be improved. In addition, the low-temperature and high-pressure refrigerant of the heat pump is decompressed and expanded by the expansion valve, but since the expansion energy of the low-temperature and high-pressure refrigerant is not effectively used, the low-level thermal energy recovery method and the coefficient of performance of the plant (Coefficent of Performance: COP) It was difficult to improve.

  The energy generator disclosed in Patent Document 2 has a complicated structure, a large number of parts, a high production cost, and an extremely low energy output, so that it can be put to practical use as a new energy generator that can be used in various low-temperature thermal power generation systems. I couldn't.

  On the earth, atmospheric heat such as indoor air and outdoor air, exhaust heat from buildings and factories (hereinafter referred to as “atmospheric heat source”), underground heat, soil heat, desert heat, etc. (hereinafter referred to as “large geothermal heat source”) Is present as a large amount of unused energy. However, the above-described low thermal energy recovery method, plant, and energy generator cannot effectively utilize these unused low thermal energy.

  The present invention has been made in view of such conventional problems, and provides a low thermal energy recovery method and a low thermal power generation system capable of recovering unused low thermal energy on the earth with a high coefficient of performance (COP). The purpose is to provide.

  According to the first aspect of the present invention, in the low thermal energy recovery method, a sealed power cycle and a heat pump for circulating a working fluid and a refrigerant that can be evaporated at a low boiling point by sealing at a predetermined pressure, respectively, An energy conversion device comprising a power storage unit for supplying stored power to the sealed power cycle is prepared, and a low heat recovery heat exchanger is provided by at least one low heat energy source selected from an atmospheric heat source and a ground heat source in the heat pump. The refrigerant vapor is generated from the refrigerant through a refrigerant compressor, the refrigerant vapor is compressed by a refrigerant compressor to generate a high-temperature and high-pressure refrigerant, and the heat of the high-temperature and high-pressure refrigerant is radiated to the working fluid of the hermetic power cycle and the high-pressure refrigerant The high-pressure refrigerant is decompressed and expanded by the first expander to recover the first mechanical energy and to generate the low-temperature and low-pressure refrigerant. Evaporating the low-temperature and low-pressure refrigerant to generate cold, compressing the working fluid absorbed from the high-temperature and high-pressure refrigerant in the sealed power cycle by a fluid compressor to generate a high-temperature and high-pressure working fluid, and To generate a pulsed electric power, and by energizing the high enthalpy converter with the pulsed electric power, it is heated to a predetermined temperature higher than the heat receiving temperature of the working fluid, and the high-temperature high-pressure working fluid is combined with the high enthalpy converter. A high enthalpy power fluid is generated by contact, and the second mechanical energy is recovered while the high enthalpy power fluid is expanded by a second expander connected to the first expander via an output shaft, and the output The refrigerant compressor and the fluid compressor are driven in part while outputting the first and second mechanical energy through the shaft, and the cold expander is used to drive the second expander. Characterized by reproducing with said refrigerant and said working fluid by cooling the Zhang gas.

  According to the invention described in claim 2, in addition to the structure described in claim 1, preferably, the atmospheric heat source includes air heat and factory exhaust heat and building exhaust heat, and the ground heat source is heat of the ground. , Including ground heat and soil heat, in the energy conversion device, the first and second mechanical energy is supplied to the generator via the output shaft to generate electric power, and a part of the electric power is used for power storage. The electric power is supplied to the power storage unit, and the high-temperature and high-pressure working fluid is temporarily stored in the buffer damper against the force of the spring, and is substantially over the entire expansion stroke of the second expander. The control valve is opened to supply the high-temperature and high-pressure working fluid to the high enthalpy converter, and the buffer damper and the control valve function as starters for the first and second expanders.

  According to the second aspect of the present invention, the low-order thermoelectric power generation system includes a sealed power cycle and a heat pump that circulate a working fluid and a refrigerant that can be evaporated at a low boiling point by being sealed at a predetermined pressure, and the heat pump, An energy conversion device having a power storage unit for supplying stored power to a sealed power cycle, and the heat pump heats and evaporates the refrigerant by heat exchange with at least one lower heat energy selected from an atmospheric heat source and a ground heat source. A lower heat recovery heat exchanger that generates refrigerant vapor, a refrigerant compressor that compresses the refrigerant vapor to generate a high-temperature and high-pressure refrigerant, and dissipates the heat of the high-temperature and high-pressure refrigerant to the working fluid of the hermetic power cycle. A radiator that generates a high-pressure refrigerant, a first expander that recovers the first mechanical energy by decompressing and expanding the high-pressure refrigerant and generating a low-temperature and low-pressure refrigerant; An evaporating heat exchanger that evaporates the low-temperature and low-pressure refrigerant to generate cold, and the fluid compressor that compresses the working fluid that has absorbed heat from the high-temperature and high-pressure refrigerant to generate the high-temperature and high-pressure working fluid. A pulse power source that generates pulse power using the stored power, and generates high enthalpy power fluid from the high-temperature high-pressure working fluid by energizing with the pulse power and generating heat to a predetermined temperature higher than the heat receiving temperature of the working fluid A high enthalpy converter, a second expander connected to the first expander via an output shaft and recovering second mechanical energy by expanding the high enthalpy power fluid, and the heat exchange for evaporation A cooler that regenerates the working fluid and the refrigerant while cooling the expansion gas of the second expander by the cold heat, and the first and second mechanical energy taken out from the output shaft. A generator that generates electric power by being driven by a power source, and a charger that charges a part of the electric power to the electric storage unit as electric power for electric storage, and the first and second mechanical energy are supplied via the output shaft. A part is supplied to and driven by the refrigerant compressor and the fluid compressor, and the working fluid is returned to the fluid compressor via the radiator.

  In the low thermal energy recovery method and low thermal power generation system of the present invention, refrigerant vapor is generated from the refrigerant via the low heat recovery heat exchanger by at least one low thermal energy source selected from the atmospheric heat source and the ground heat source in the heat pump. This is compressed by a refrigerant compressor to generate a high-temperature and high-pressure refrigerant, and the heat is radiated to the working fluid of the sealed power cycle to recover the heat derived from the lower thermal energy. The high-pressure refrigerant generated at this time is decompressed and expanded by the first expander to recover the first mechanical energy, and in the sealed power cycle, the working fluid absorbed from the heat pump is compressed by the fluid compressor to generate a high-temperature and high-pressure working fluid. However, this is converted into a high enthalpy power fluid by, for example, contacting with a high enthalpy converter that generates heat at about 800 ° C. The second mechanical energy is recovered by expanding the high enthalpy power fluid in the second expander, and the refrigerant and working fluid are cooled by cooling the expansion gas of the second expander using the cold generated by the heat pump. Playing. As described above, the first and second mechanical energy can be recovered from the low thermal energy with a very high coefficient of performance (COP). Since the high enthalpy power fluid is continuously supplied to the second expander (over the entire expansion stroke), the net effective average pressure of the second expander is as high as about 250 to 450 kgf / cm2, Compared to the net effective average pressure of 13.5 kgf / cm <2> of the racing car, the size is several tens of times larger. Therefore, it is possible to extract very large mechanical energy using low thermal energy, and supply it to the generator to continuously obtain stable and high-quality electric power of several tens of kilowatts to several hundred megawatts. A great contribution can be made to the prevention of global warming.

  In addition, by supplying a part of the power to the power storage unit as the power for power storage, the low-level thermal power generation system can be self-supporting. Energy and electrical energy can be recovered. Further, the high-temperature and high-pressure working fluid is temporarily stored by the buffer damper against the force of the spring, and is opened by the control valve. Therefore, when the energy conversion device is started up, it is possible to generate a high enthalpy power fluid by inflating it with the second expander by discharging the high pressure working fluid from the buffer damper to the high enthalpy converter just by opening the control valve It is said. Therefore, the simple operation of the key switch can be used to start the low-level thermal power generation system whenever necessary, which is highly convenient.

1 shows a block diagram of a lower thermal power generation system for executing a lower thermal energy recovery method according to an embodiment of the present invention. FIG. Sectional drawing of the composite type compressor of the low-order thermoelectric power generation system of FIG. 1 is shown. FIG. 2 shows a cross-sectional view of the high enthalpy converter of the low thermal power generation system of FIG. 1.

  Hereinafter, a low thermal power generation system for executing a low thermal energy recovery method according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, the low-level thermal power generation system is described as being applied to a stationary structure. However, when an atmospheric heat source is used as low-level thermal energy, an oscillator or construction machine such as a ship, aircraft, railroad train, or automobile is used. It can be applied to a mechanical device driven by a power source such as a harbor machine.

  In the embodiment shown in FIG. 1, the low-level thermoelectric power generation system 10 includes a sealed power cycle 15 and a heat pump HP that circulate a working fluid and a refrigerant that are allowed to evaporate at a low boiling point by being sealed at a predetermined pressure, respectively. An energy storage unit 20 that supplies stored power to the sealed power cycle 15 and includes an energy conversion device 12 that recovers mechanical energy from lower thermal energy, and an output device 16 that transmits the mechanical energy. The output device 16 includes a clutch CL that selectively cuts off or fastens the mechanical energy of the energy conversion device 12, and a generator GE that is driven by the mechanical energy to generate electric power.

  Although the present invention is not limited as a working fluid and a refrigerant, it is a safe substance that exists in nature, and because it can be obtained at a very low cost, the ozone depletion coefficient is zero and the global warming potential Is carbon dioxide (hereinafter referred to as CO2), which is a natural refrigerant. For convenience of explanation, the working fluid of the sealed power cycle 12 is referred to as a CO2 working fluid, and the refrigerant of the heat pump HP is referred to as a CO2 refrigerant. Thus, although the working fluid and the refrigerant use carbon dioxide, which is a common component, different media may be used. In the sealed power cycle 15 and the heat pump HP, the present invention is not limited. However, the pressure on the low pressure side is set to a predetermined pressure below the supercritical point of CO2, for example, 2 to 5.7 MPa. Filled. In this case, the filling pressure of the CO2 refrigerant is selected according to the heat collection temperature of the lower thermal energy to be used. For example, if the pressure on the low pressure side of the CO2 refrigerant is filled to 2.5 MPa, the CO2 refrigerant evaporates at about -11 ° C, so the liquefied CO2 refrigerant exchanges heat with an atmospheric heat source that is -11 ° C or higher. It can be easily evaporated to obtain superheated steam (refrigerant vapor), and it is possible to pump up lower heat energy.

  The hermetic power cycle 15 includes a compressor (composite rotary fluid machine) 27 that compresses the low-temperature low-pressure CO 2 working fluid Wf at a pressure higher than the supercritical point (31.1 ° C., 7.4 MPa), that is, a so-called supercritical state. A sliding piston for temporarily storing the high-temperature and high-pressure CO 2 working fluid (supercritical fluid) Wfp discharged from the compressor 27 through the check valve 29 and discharging it while suppressing the pulsation of the supercritical fluid; A buffer damper 30 having a storage chamber 30b containing a spring means 30a; a solenoid valve (control valve) 32 for controlling the flow (circulation period) of the supercritical fluid Wfp supplied from the outlet 30c of the buffer damper 30; The supercritical fluid Wfp supplied from the buffer damper 30 generates heat at a temperature (for example, 600 to 1200 ° C.) higher than the supercritical point (31.1 ° C.), thereby increasing the high enthalpy. A high enthalpy converter 42 that generates a force fluid (high enthalpy supercritical fluid), a high-pressure refrigerant Cmh of the heat pump HP, and a supercritical fluid Scf are introduced into the working chamber 116 and expanded, and the first and second mechanical energy The rotary fluid machine 40 including the first and second rotary fluid machine sections (first and second expanders) 40A and 40B that generate and the first and second mechanical energy are extracted and a part thereof is compressed. And an output shaft 132 that is transmitted to the machine 27. The first and second expanders 40A and 40B include a common rotary piston body 200 supported by the output shaft 132 and rotatably accommodated in the working chamber 116. The high-pressure refrigerant Cmh and supercritical fluid are contained in the working chamber 116. It has inlets 124A and 124B for supplying the fluid Scf, respectively, and outlets 126A and 126B for discharging the low-temperature and low-pressure refrigerant Cme and the expansion gas Eg, respectively.

  The spring means 30a of the buffer damper 30 is selected so that the pressure of the high-pressure CO2 working fluid (supercritical fluid) in the storage chamber 30b is maintained at, for example, 20 to 60 MPa. Therefore, in the sealed power cycle 15, the pressure in the first fluid pressure path between the check valve 29 and the solenoid valve (control valve) 32 is maintained at 20 to 60 MPa, and the remaining second fluid pressure path (rotary fluid) The closed power cycle 15 is filled with the CO 2 working fluid so that the low pressure side of the machine 40 is maintained at, for example, 4.4 MPa (the refrigerant evaporation temperature (heat collection temperature) is 10 ° C.). The compressor 27, for example, discharges a supercritical fluid at a pressure of 20 to 60 MPa, so that the spring means 30a of the buffer damper 30 is always maintained in a compressed state during the operation of the sealed power cycle 15, and is super The critical fluid Wfp is stored.

  The solenoid valve 32 has the same structure as that described in Japanese Patent No. 5272278 entitled “Supercritical Engine, Supercritical Engine Driven Power Generation Device and Low-Level Thermal Power Generation System Having the Same” by the same inventor as the present inventor. Detailed description will be omitted.

  The heat pump HP includes a lower heat recovery heat exchanger EVo that heats and evaporates a refrigerant by heat exchange with lower heat energy Es such as an atmospheric heat source or a ground heat source, and generates superheated steam (refrigerant vapor) Cm, and superheated steam Cm. The refrigerant compression means P2 that compresses and generates the high-temperature and high-pressure refrigerant Cmp, the radiator EV2 that generates the high-pressure refrigerant Cmh by radiating the heat of the high-temperature and high-pressure refrigerant Cmp to the working fluid Wfo of the sealed power cycle 15, and the high-pressure refrigerant Cmh The first expander 40A that recovers the first mechanical energy by decompressing and expanding, and the low-temperature and high-pressure refrigerant Cme that has come out of the first expander 40A is evaporated to generate cold, and the expansion gas Eg of the second expander 40B is generated. And an evaporator (heat exchanger) EV1 functioning as a cooler 43 for cooling. The low-temperature and low-pressure expansion gas Wfo emitted from the cooler 43 absorbs heat from the high-temperature and high-pressure CO2 refrigerant Cmp in the radiator EV2, thereby generating superheated steam Wf as a low-temperature and low-pressure working fluid, and fluid compression means of the compressor 27 of the hermetic power cycle 15 Installed in P1 inlet 356A. On the other hand, the superheated steam Cm emitted from the lower heat recovery heat exchanger EVo is introduced into the inlet 356B of the refrigerant compression means P2. Thereafter, the same heat pump cycle and power cycle are repeatedly executed.

  Here, the lower heat recovery heat exchanger EVo is appropriately arranged according to the form of these lower heat sources. For example, when collecting heat from a large geothermal source, the low heat recovery heat exchanger EVo is configured with a metal coil so that CO2 refrigerant is circulated therein. What is necessary is just to arrange | position or embed | buy in the surface of a remaining layer part or a desert, or the remaining layer part, and to arrange | position so that these earth heat sources may be contacted. When heat is collected from an atmospheric heat source, the lower heat recovery heat exchanger EVo made of a metal coil may be installed in the air or in an exhaust flow of a factory, a building, or the like.

  As is apparent from FIG. 2, the compressor 27 preferably compresses the CO2 working fluid (superheated steam) Wf having a predetermined pressure (for example, 4.4 MPa) at a pressure equal to or higher than the supercritical point to compress the supercritical fluid (CO2 Supercritical fluid) Fluid compression means P1 that generates Wfp, and refrigerant compression means P2 that compresses the low-temperature and low-pressure CO2 refrigerant (superheated steam) Cm above the critical point to generate high-temperature and high-pressure CO2 refrigerant (supercritical fluid) Cmp. It is composed of a combined rotary fluid machine equipped. The reason for compressing the superheated steam of the CO2 working fluid and the CO2 refrigerant with the compressor 27 is that the power required for compressing these fluids is greatly reduced (about one-fifth compared with normal gas compression) and the coefficient of performance ( This is to dramatically improve (COP).

  As shown in FIG. 1 and FIG. 2, the composite compressor 27 is connected to a rotor housing 352 concentrically connected to a rotary fluid machine 40 and a high enthalpy converter 42, and connected to the sealed power cycle 15 for low temperature and low pressure. A first inlet 356A for introducing a CO2 working fluid Wf, a first outlet 358A for discharging a supercritical CO2 working fluid (supercritical fluid) Wfp, a second inlet 356B for introducing a low-temperature low-pressure refrigerant Cm, and a supercritical CO2 refrigerant The second outlet 358B that discharges Cmp, the rotor working chamber 360 in which the inlets 356A and 356B and the outlets 358A and 358B are opened, and the rotor connected to the output shaft 132 of the rotary fluid machine 40 by press-fitting or other connecting means. A crank rotor 362 rotatably accommodated in the working chamber 360.

  The crank rotor 362 includes a lubricating oil passage 362a extending radially outward from the main lubricating oil supply passage 132L formed in the output shaft 132, a lubricating oil supply port 362b, and the lubricating oil supply port 362b to the outer peripheral end of the lobe 364. And a porous plug 362c capable of supplying a small amount of lubricating oil. Lubricating oil is supplied to the main lubricating oil supply passage 132L by a lubricating oil pump or the like described in Japanese Patent No. 5103570 “Rotating fluid machine” by the same inventor as the present inventors. The composite compressor 27 further sucks the CO2 working fluid Wf and the refrigerant Cm from the inlets 356A and 356B while rotating and swinging on the inner peripheral surface of the rotor working chamber 360, and compresses these fluids to a supercritical pressure. However, a plurality of lobes 364 discharged from the outlets 358A and 358B, a curved sliding recess 366 formed at the circumferential rear edge in the radially inner region of the lobe 364, and the crank rotor 362 adjacent to the inlet 356 A swingable piston 368 that can swing, and a compression chamber 370 formed between the swinging piston 368 and the curved sliding recess 366 are provided.

  The swing piston 368 is housed in a piston swing chamber 372 formed in the rotor housing 352 and includes a piston element 376 that rotates via a pivot shaft 374. The tip of the piston element 376 includes a curved seal portion 376a and a communication opening 376b that slide while contacting the lobe 364 and the curved sliding recess 366. A pressure spring 380 presses the piston element 376 toward the crank rotor 362 in the spring housing portion 378 formed in the rotor housing 352. When the output shaft 132 is driven to rotate in the clockwise direction in FIG. 2, for example, when the rotary fluid machine 40 is activated, in the composite compressor 27, the CO2 working fluid Wf and the inlets 356A and 356B are respectively supplied to the compression chamber 370. Refrigerant Cm is sucked and discharged from outlets 358A and 358B as supercritical fluid and supercritical CO2 refrigerant, respectively. Thus, the crank rotor 362 of the compressor 27 functions as a common part of the working fluid compression means P1 and the refrigerant compression means P2.

  The composite compressor 27 is the same as the rotary pump described in Japanese Patent Application No. 2012-218058 “Rotary Combustion Engine, Hybrid Rotary Combustion Engine, and Low-Level Thermal Power Generation System Having These” by the same inventor as the present inventor. Since it has a structure, further detailed description is omitted. As the composite compressor 27, a rotary fluid machine described later by the same inventor as the present application may be used.

  As shown in FIG. 3, the high enthalpy converter 42 includes a cylindrical reactor casing 1100 that is concentrically connected to the composite compressor 27 and the rotary fluid machine 40. The cylindrical reactor casing 1100 is formed on the inner side of the cylindrical reactor casing 1100 and the insulating heat resistant layer 1116 such as ceramic formed on the radially outer side of the central inner peripheral portion 1114 of the casing 1100, and on the inner side of the insulating heat resistant layer 1116. An enthalpy amplification chamber 1118 is formed. A central inner peripheral portion 1114 of the cylindrical reactor casing 1100 includes an inner peripheral wall portion 1114 having a diameter for allowing the output shaft 132 of the rotary fluid machine 40 to pass therethrough.

  The suction port 1102 of the high enthalpy converter 42 extends to the radial wall 1120 and is fitted with the electromagnetic valve 32, and the radial wall 1120 has a plurality of openings 1122 extending in the circumferential direction. Counter electrodes 1124 and 1126 are disposed at corner portions 1118a and 1118b of the enthalpy amplification chamber 1118, respectively. The pair of electrodes 1124 and 1126 are connected to the pulse power supply 28. A temperature sensor S2 is attached to the casing 1100, and a temperature signal T is supplied to the controller 60 (see FIG. 1) and used for controlling the pulse width of the pulse power.

  The enthalpy amplification chamber 1118 is filled with a large number of tubular energization heating elements 1134 such as copper tungsten pipes or stainless steel pipes interposed between the counter electrodes 1124 and 1126. In response to the pulse power, the large number of tubular energization heating elements 1134 generate energization and maintain in the supercritical region of 600 to 1200 ° C. This temperature range is achieved by variably controlling the pulse power source 28 so that the duty cycle of the pulse power becomes a predetermined value. The CO 2 supercritical fluid passes through the gap between the energized heat generating pipe 1134 and the hole of the energized heat generating pipe 1134. At this time, it is heated while colliding with each part of these energized heat generating pipes 1134, and a high enthalpy supercritical fluid is instantaneously generated as a power fluid.

  A conductive high melting point heating means may be used in place of the energization heat generating pipe 1134. For example, using a copper tungsten ball, a carbon ball, a bulk conductive metal body in which a groove for allowing a working fluid to pass, a bulk conductive carbon, a porous refractory metal body, a refractory honeycomb metal body, etc. are used. Also good. A filter portion 1106 is disposed adjacent to the enthalpy amplification chamber 1118, and the filter portion 1106 is filled with a filter 1110 formed of a heat-resistant metal wire or the like. When the electromagnetic valve 32 is opened at a predetermined cycle, the power fluid Scf that has passed through the filter 1110 is filtered by the filter 1142 and then supplied from the outlet 1140 to the inlet 124 of the rotary fluid machine 40.

  The rotary fluid machine 40 is preferably Japanese Patent No. 5103570 (Title of the invention: rotary fluid machine) and Japanese Patent No. 5218929 (Title of the invention: rotary combustion engine, hybrid rotary) by the same inventor as the present inventors. And the same structure as the rotary fluid machine disclosed in (combustion engine and low-temperature thermal power generation system including these). As another example, a structure described in Japanese Patent Application No. 2012-259090 (title of the invention: rotary fluid machine) by the same inventor as the present inventor may be used.

  Returning to FIG. 1, the generator GE is drivably coupled to the output shaft 132 of the energy conversion device 12 via the output device 16 to generate AC power. A load (not shown) such as an electric device is connected to the power line PL of the generator GE. A power storage unit (power storage system) 20 is connected to the power line PL via a circuit breaker 19 including a transformer 50 and a relay. The transformer 50 steps down the AC voltage (for example, 200 to 240 V) output from the generator GE to a low-voltage AC voltage, for example, 12 or 24 volt AC voltage. The power storage unit 20 is connected to the power line PL via the circuit breaker 19 and supplied with a part of the generated power, the first power storage device 22, the second power storage device 23, the first, A first switching controller 24 for alternately connecting the second power storage devices 22, 23 to the charger 21; and a second switching controller 26 for alternately connecting the first and second power storage devices 22, 23 to the pulse power supply 28; Is provided. Although not shown, the charger 21 includes a rectifier that converts low-voltage AC power into DC power and a smoothing circuit, as in a known structure. A voltage sensor and a current sensor (both not shown) for detecting an output voltage and an output current are connected to the first and second power storage devices 22 and 23, respectively. The voltage detection value V1 and the current detection value I1 of these voltage sensors and current sensors are output to the controller 60, and the respective remaining storage capacities (SOC values: State of charge) of the first and second power storage devices 22 and 23 are calculated. These are used to output command signals from the circuit breaker 19 and the first and second switching controllers 24 and 26 based on the respective SOC values.

  The controller 60 includes, for example, a CPU (Central Processing Unit) that executes predetermined arithmetic processing, a ROM (Read Only Memory) that stores a predetermined control program, and a RAM (Random Access Memory) that temporarily stores data. For example, an EEPROM (Electrically Erasable and Programmable Read Only Memory) is used. The controller 60 is connected to an input device (not shown) for inputting control parameters to be controlled, a device start switch (not shown), and the like.

  As the first and second power storage devices 22, 23, an engine starting battery (part number: ESM123000-31) using a commercially available ultracapacitor module that can be applied to pulse charge / discharge cycle applications (US ”Maxwell Technologies) “Made by company” can be mentioned. This battery is suitable because it can be charged for a short time in 15 minutes, the output voltage is 12 volts, and the output current is 1500-1700A. Other power storage devices include, for example, rapid charge / discharge type storage batteries (Furukawa Battery Co., Ltd .: trade name “Ultra Battery”), supercapacitors (made by Tokin) consisting of large-capacity electric double layer capacitors, sodium ion batteries, lithium ion batteries Or a Ni-MH battery (nickel-hydrogen battery) or a combination of these batteries and a large-capacity electric double layer capacitor. An ultracapacitor (not shown) may be connected between the output lines of the first power storage device 22. Output power is alternately supplied from the first power storage device 22 and the second power storage device 23 to the pulse power supply 28.

  The pulse power supply 28 supplies pulse power having a predetermined cycle (for example, 50 to 2000 hertz) from the power supplied from the first and second power storage devices 22 and 23. In the pulse power, the pulse voltage is preferably set between 12 and 24 volts, for example. Depending on the capacity of the energy conversion device 12, the pulse current preferably has a peak current of 20 to 200 amperes flowing during the peak current energization period and a current value of about one tenth of the peak current. A base current that flows within a period may be included. In the high enthalpy converter 42, a large number of energized heat generating pipes 1134 are energized in response to pulse power to raise the temperature to a carbon dioxide critical temperature of 374 ° C. or higher, for example, 600 to 1200 ° C. This temperature is freely selected according to the operating conditions. In the process in which the supercritical fluid sequentially contacts and passes the outer surface of the energized heat generating pipe 1134, the power fluid is heated under supercritical conditions to become a high enthalpy supercritical fluid Scf.

  The pulse power source 28 is preferably a DC pulse power source or an AC pulse power source as long as it generates a pulse current. Examples of the direct-current pulse power supply include a circuit configuration similar to a power supply device for pulse arc welding as disclosed in Japanese Patent No. 2587343.

  In FIG. 1, the pressure signal PS from the pressure sensor S1 of the buffer damper, the temperature signal T (see FIG. 4) from the temperature sensor S2 of the high enthalpy converter 42, and the rotational speed sensor of the output shaft 132 of the energy conversion device 12 The rotation speed signal SP from S3 is transmitted to the controller 60. From an input device (not shown), a calendar signal and a parameter setting signal such as temperature and pressure are input to the controller 60 as a reference signal. The voltage signal V1 and current signal I1 of each of the first and second capacitors 22 and 23 are transmitted to the controller 60, and the controller 60 stores the charges of the first and second capacitors 22 and 23 in response to these input signals. The state (remaining storage capacity) (State of Charge) is determined, and one of the first and second power storage devices 22 and 23 is connected to the pulse power supply 28 via the second switching controller 26 and the first switching controller 24. The other of the first and second power storage devices 22 and 23 is charged by the charger 21 via Further, the controller 60 controls the electromagnetic valve 32 in response to the input signals PS, T, SP from the sensors S1 to S3. At this time, the controller 60 controls the rotary fluid machine 40 to maintain the electromagnetic valve 32 in the open state during the entire expansion stroke of the second rotary fluid machine unit 40B. Accordingly, the power fluid continuously acts on the second rotary fluid machine unit 40B during the entire period of the expansion stroke. On the other hand, the controller 60 outputs a control signal Cc for engaging / disengaging the clutch CL in accordance with the operating conditions of the low-level thermal power generation system 10.

  Next, the low thermal energy recovery method according to the present invention will be described in relation to the description relating to the operation of the energy conversion device 12 of the present embodiment.

  In the operation of the energy conversion device 12, a device start switch (not shown) is first turned on. At this time, the pulse power supply 28 is activated by the controller 60, and periodic pulse power is supplied to the high enthalpy converter 42. Then, the energization heat generating pipe 1134 is energized and generates heat to a desired set temperature (for example, 800 ° C.). When the temperature signal T of the high enthalpy converter 42 reaches this set temperature, a command signal is output from the controller 60 to the electromagnetic valve 32, and the electromagnetic valve 32 is energized to open. At this time, the CO 2 working fluid Wfp stored in the buffer damper 30 is supplied to the high enthalpy converter 42. In the high enthalpy converter 42, the CO2 working fluid Wfp comes into contact with the outer surface of the heat generating pipe 1134 in sequence and is uniformly heated while being stirred, and further heated while passing through gaps and holes in the heat generating pipe 1134. However, the supercritical fluid SCf is generated as a high enthalpy power fluid. The high enthalpy power fluid SCf flows into the expansion chamber 116 from the inlet 124B of the second rotary fluid machine unit 40B and acts on the rotary piston main body 200 to explode and generate mechanical energy to generate the output shaft 132. introduce.

  The composite compressor 27 is activated by the torque generated in the output shaft 132 when the energy conversion device 12 is started and after the start is completed, and the fluid compression means P1 and the refrigerant compression means P2 in the compressor 27 are operated synchronously. The sealed power cycle 15 and the heat pump HP are activated in synchronization with each other. At this time, in the heat pump HP, the refrigerant vapor Cm generated by the heat pumped from the low heat energy Es such as the atmospheric heat source or the earth heat source via the low heat recovery heat exchanger EVo is compressed in the supercritical state by the refrigerant compression means P2. Thus, a supercritical refrigerant (high temperature high pressure CO2 refrigerant) Cmp is generated. This supercritical refrigerant (high-temperature high-pressure CO2 refrigerant) Cmp exchanges heat with the low-temperature low-pressure CO2 working fluid Wfo in the radiator EV2 to radiate heat, thereby generating a low-temperature high-pressure CO2 refrigerant Cmh. The low-temperature high-pressure CO2 refrigerant Cmh is decompressed and expanded by the first expander 40A to be converted into first mechanical energy, and generates a low-temperature low-pressure CO2 refrigerant Cme. The low-temperature low-pressure CO 2 refrigerant Cme evaporates in the cooler 43 (heat exchanger EV1) to generate cold (for example, −10 ° C .: 4.4 MPa) to cool the expansion gas Eg. The low-temperature and low-pressure refrigerant Cmo discharged from the cooler 43 is circulated to the refrigerant compressor means P2 of the compressor 27 as refrigerant vapor (low-temperature and low-pressure CO2 refrigerant) Cm by the low-order heat recovery heat exchanger EVo by the low-order heat energy Es. On the other hand, the low-temperature low-pressure CO2 working fluid Wfo generated by being cooled by the evaporator EV1 receives heat from the supercritical refrigerant Cmp by the radiator EV2 and flows into the inlet 356A of the compressor 27 as the CO2 working fluid Wf made of superheated steam. After being compressed by the compression means P1, the sealed power cycle 15 is repeatedly executed thereafter.

  As described above, the sealed power cycle 15 and the heat pump HP are repeatedly executed in synchronization with each other. At this time, the heat of the high-temperature high-pressure CO2 refrigerant is radiated to the low-temperature low-pressure CO2 working fluid of the sealed power cycle 15, and then the low-temperature high-pressure CO2 refrigerant expands in the first expander to generate the first mechanical energy, The high enthalpy power fluid (high enthalpy supercritical fluid) generated by the high enthalpy converter 42 is expanded by the second expander to recover the second mechanical energy. As described above, the first mechanical energy and the second mechanical energy are recovered by efficiently recovering the thermal energy from the lower thermal energy such as the atmospheric heat source or the earth heat source. The mechanical energy thus obtained is supplied to the generator GE via the output shaft 132 and the output device 16 to generate electric power. Part of this electric power is stored in the power storage unit 20 from the power line PL via the transformer 50 and the charger 21 and used as power supplied to the pulse power source 23.

  Although the low thermal energy recovery method and the low thermal power generation system according to the embodiment of the present invention have been described above, the present invention is not limited to the configuration shown in this embodiment, and various modifications can be made. For example, the compressor has been described as being composed of a composite compressor, but the composite compressor may be composed of a working fluid compressor and a refrigerant compressor that are separated and independent from each other. Moreover, although the refrigerant compression means and the working fluid compression means are described as single-stage types, they may be modified so as to compress the refrigerant and the working fluid in a plurality of stages.

12 Energy conversion device; 15 Sealed power cycle; 16 Output device; 20 Power storage unit (power storage system); 21 Charger; 22, 23 First, second power storage device; 24, 26 First, second switching controller; 27 Compressor (composite rotary fluid machine); 28 Pulse power supply; 30 Buffer damper; 32 Solenoid valve; 40 Rotary fluid machine; 40A First expander (first rotary fluid machine part); 40B Second expander (second rotary fluid machine part); 42 high enthalpy converter; 43 cooler; 60 controller; HP heat pump; EVo low heat recovery heat exchanger; EV1 cooler (heat exchanger); EV2 radiator

Claims (4)

  An energy conversion device is provided that includes a sealed power cycle and a heat pump that circulate a working fluid and a refrigerant that can evaporate at a low boiling point by sealing at a predetermined pressure, and a power storage unit that supplies stored power to the sealed power cycle. Then, in the heat pump, refrigerant vapor is generated from the refrigerant via the lower heat recovery heat exchanger by at least one lower heat energy source selected from the atmospheric heat source and the earth heat source, and the refrigerant vapor is compressed by the refrigerant compressor. The high-temperature high-pressure refrigerant is generated, the heat of the high-temperature high-pressure refrigerant is radiated to the working fluid of the hermetic power cycle, the high-pressure refrigerant is generated, and the high-pressure refrigerant is decompressed and expanded by the first expander. Recovering energy and producing a low-temperature and low-pressure refrigerant, evaporating the low-temperature and low-pressure refrigerant to produce cold, and in the sealed power cycle, The working fluid that has absorbed heat from the hot / high pressure refrigerant is compressed by a fluid compressor to generate a high-temperature / high-pressure working fluid, and the stored electric power is supplied to a pulse power supply to generate pulse power. By heating the working fluid to a predetermined temperature higher than the heat receiving temperature of the working fluid, and bringing the high-temperature and high-pressure working fluid into contact with the high enthalpy converter to generate a high enthalpy power fluid and outputting the output shaft to the first expander. The second mechanical energy is recovered while expanding the high enthalpy power fluid with the second expander connected via the first and the first mechanical energy and the second mechanical energy are output via the output shaft. The refrigerant compressor and the fluid compressor are driven, and the refrigerant and the working fluid are regenerated by cooling the expansion gas of the second expander using the cold heat. Low-grade heat energy recovery method.   The atmospheric heat source includes air heat and factory exhaust heat and building exhaust heat, and the ground heat source includes ground heat, ground heat, and soil heat. In the energy conversion device, the first heat is output via the output shaft. And the second mechanical energy is supplied to the generator to generate electric power, a part of the electric power is supplied to the electric storage unit as electric storage electric power, and the high-temperature and high-pressure working fluid is buffered against the spring force Temporarily storing in an damper, opening the control valve and supplying the high-temperature and high-pressure working fluid to the high enthalpy converter over substantially the entire expansion stroke of the second expander, and the buffer damper 2. The low thermal energy recovery method according to claim 1, wherein the control valve and the control valve function as starters for the first and second expanders.   An energy conversion device having a sealed power cycle and a heat pump that circulates a working fluid and a refrigerant that can be evaporated at a low boiling point by being sealed at a predetermined pressure, and a power storage unit that supplies stored power to the sealed power cycle; The heat pump heats and evaporates the refrigerant to generate refrigerant vapor by heat exchange with at least one lower thermal energy selected from an atmospheric heat source and a ground heat source, and compresses the refrigerant vapor A refrigerant compressor that generates a high-temperature and high-pressure refrigerant, a radiator that radiates the heat of the high-temperature and high-pressure refrigerant to the working fluid of the hermetic power cycle and generates a high-pressure refrigerant, and depressurizes and expands the high-pressure refrigerant. 1 A first expander that recovers mechanical energy and generates a low-temperature and low-pressure refrigerant; and an evaporation heat exchanger that generates cold by evaporating the low-temperature and low-pressure refrigerant. A fluid compressor that compresses the working fluid that has absorbed heat from the high-temperature and high-pressure refrigerant to generate a high-temperature and high-pressure working fluid; a pulse power source that generates pulse power using the stored power; and the pulse power A high enthalpy converter for generating a high enthalpy power fluid from the high-temperature and high-pressure working fluid by being energized by the heat and generating heat to a predetermined temperature higher than the heat receiving temperature of the working fluid, and connected to the first expander via the output shaft A second expander that recovers second mechanical energy by expanding the high enthalpy power fluid and a heat exchanger for evaporating to cool the expansion gas of the second expander by the cold heat. A cooler that regenerates the working fluid and the refrigerant, and a generator that generates electric power driven by the first and second mechanical energy extracted from the output shaft. A part of the first and second mechanical energy is supplied to and driven by the refrigerant compressor and the fluid compressor, and the working fluid is returned to the fluid compressor via the radiator. A low-temperature thermal power generation system.   The energy conversion device further includes a charger that charges the power storage unit with a part of the power as power for storage, and a buffer damper that temporarily stores the high-temperature and high-pressure working fluid against the force of a spring; And a control valve for supplying the high-temperature and high-pressure working fluid to the high enthalpy converter over substantially the entire expansion stroke of the second expander. .

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