JP2010043800A - Vapor generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vapor generation system capable of stably exhibiting high energy efficiency. <P>SOLUTION: The vapor generation system includes a heat pump 10 through which first fluid flows, an evaporation unit 20 through which second fluid flows, and a heat recovery mechanism 80. The heat pump 10 includes a heat absorbing part 11, a compression part 12, heat radiation parts 13A, 13B and 13E, and an expansion part 14. The second fluid receiving transmission heat from the first fluid is evaporated in the evaporation unit 20. The heat recovery mechanism 80 includes a warmer 41 for warming the second fluid flowing to an evaporation part 22 by the first fluid from the heat radiation part 13B, a regenerator 18 for warming the first fluid flowing to the compression part 12 by the first fluid from the heat radiation part 13B, and an intermediate cooler 83 for cooling the first fluid flowing through a stage space of the compression part 12 by the first fluid from the heat radiation part 13B. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a steam generation system.

Patent Document 1 discloses a steam generation system that generates steam by heat transferred from a heat pump.
JP 2007-120914 A

  In a steam generation system using a heat pump, a coefficient of performance (COP) may change according to at least one of the temperature and flow rate of the heat medium supplied to the heat absorption unit.

  An object of this invention is to provide the steam production system which can exhibit high energy efficiency stably.

  According to the aspect of the present invention, the heat pump is a heat pump through which the first fluid flows, the heat pump including the heat absorption unit, the compression unit, the heat radiation unit, and the expansion unit, and the evaporation unit through which the second fluid flows. The evaporating unit including an evaporating unit that evaporates the second fluid that has received the heat of transmission; the heater that heats the first fluid from the heat dissipating unit toward the evaporating unit; and the compressing unit A regenerator that warms the first fluid from the heat radiating section toward the first fluid, and an intermediate cooler that cools the first fluid flowing between the stages of the compression section by the first fluid from the heat radiating section A steam generation system comprising: a heat recovery mechanism including:

  According to this steam generation system, the heat of the working fluid is effectively used in the heater, the regenerator, and the intercooler, and therefore high energy efficiency can be stably exhibited.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram showing a steam generation system according to the first embodiment. In FIG. 1, a steam generation system S1 includes a heat pump 10 through which a working fluid (a heating medium, a first fluid) flows, a supply system 20 (evaporation unit) for a heated fluid (a heated medium, a second fluid), and a control device. 70. In the present embodiment, the steam generation system S1 further includes a heat recovery mechanism 80 having a heat exchanger 41 (a warmer), a regenerator 18, and an intercooler 83, which will be described later. In the present embodiment, the fluid to be heated is water. The control device 70 comprehensively controls the entire system. The configuration of the steam generation system S1 can be variously changed according to the design requirements of the steam generation system S1.

  The heat pump 10 is a device that pumps heat from a low-temperature object and applies heat to a high-temperature object by a cycle including evaporation, compression, condensation, and expansion processes. A heat pump generally has the advantage of relatively high energy efficiency and, as a result, relatively low emissions of carbon dioxide and the like.

  In the present embodiment, the heat pump 10 includes a heat absorbing portion 11, a compressing portion 12, a heat radiating portion (a first heat radiating portion 13A, a second heat radiating portion 13B, a third heat radiating portion 13E), and an expansion portion 14, which are conduits. Connected through.

  In the heat absorption part 11, the working fluid flowing in the main path 15 absorbs heat from a heat source outside the cycle. In the present embodiment, the heat absorption unit 11 of the heat pump 10 is thermally connected to the heat radiating pipe 91 of the cold heat supply device 90. In the cold heat supply device 90, the heat (heat exhaust heat) of the medium (refrigerant or the like) flowing through the heat radiating pipe 91 is absorbed by the heat absorption unit 11 of the heat pump 10. The cooled medium is supplied from the cold heat supply device 90 to a predetermined facility. The heat absorption part 11 of the heat pump 10 can also be configured to absorb the heat of other heat sources such as the atmosphere.

  The compression unit 12 compresses the working fluid by a compressor or the like. At this time, the temperature of the working fluid usually increases. In this embodiment, the compression unit 12 has a multistage compression structure that compresses the working fluid into a plurality of stages, that is, has a two-stage compression structure including a first compression unit 12A and a second compression unit 12B. The number of stages of compression is set according to the specification of the steam generation system S1, and is 2, 3, 4, 5, 6, 7, 8, 9, or 10 or more. Among the various compressors such as an axial flow compressor, a centrifugal compressor, a reciprocating compressor, and a rotary compressor, a compressor suitable for compressing a working fluid is applied. Power is supplied to the compressor. The compression unit 12 may have a multiaxial compression structure in which the rotation speeds corresponding to the compression units 12A and 12B are individually controlled. Alternatively, the compression unit 12 can have a coaxial compression structure. The compression ratio (pressure ratio) of the compression unit 12 is set according to the specification of the steam generation system S1.

  The heat radiating parts 13A, 13B, and 13E have a conduit through which the working fluid compressed by the compressing part 12 flows, and give the heat of the working fluid flowing in the main path 15 to a heat source outside the cycle. In the present embodiment, three heat radiating portions 13A, 13B, and 13E are arranged substantially in series along the flow direction of the working fluid. The number of heat radiation units is set according to the specification of the steam generation system S1, and is 3, 4, 5, 6, 7, 8, 9, 10, or 11 or more. The first heat radiating portion 13A is disposed between the compression portions 12A and 12B, the second heat radiating portion 13B is disposed at the downstream position of the compression portion 12B, and the third heat radiating portion 13E is disposed at the downstream position of the second heat radiating portion 13B. Placed in.

  The expansion unit 14 expands the working fluid by a pressure reducing valve, a turbine, or the like. At this time, the temperature of the working fluid usually decreases. When a turbine is used, power can be taken out from the expansion unit 14, and the power may be supplied to the compression unit 12, for example. As a working fluid used in the heat pump 10, various known heat media such as a fluorocarbon medium (HFC 245fa, R134a, etc.), ammonia, water, carbon dioxide, air, etc. are used for the specification and heat balance of the steam generation system S1. Used accordingly. At least a part of the working fluid flowing through the heat radiating portions 13A and 13B of the heat pump 10 may be in a supercritical state.

  In the present embodiment, the heat pump 10 further includes a bypass path 17 and a regenerator 18. The inlet end of the bypass path 17 is fluidly connected to a conduit between the heat radiation parts 13A and 13B and the third heat radiation part 13E in the main path 15 of the heat pump 10. The outlet end of the bypass path 17 is fluidly connected to a conduit between the third heat radiating part 13 </ b> E and the expansion part 14 in the main path 15. A flow rate control valve for controlling the bypass flow rate of the working fluid can be provided at the inlet of the bypass passage 17. In the bypass path 17, part of the working fluid from the first and second heat radiating portions 13 </ b> A and 13 </ b> B bypasses the third heat radiating portion 13 </ b> E and merges with the working fluid from the third heat radiating portion 13 </ b> E before the expansion portion 14. To do. Another working fluid from the first and second heat radiating portions 13A and 13B flows through the third heat radiating portion 13E, and heat exchange is performed between the working fluid and water in the supply system 20 in the heat exchanger 41 described later.

  The regenerator 18 has a configuration in which a part of the conduit of the bypass path 17 and a part of the conduit of the main path 15 of the heat pump 10 (the conduit between the heat absorption unit 11 and the compression unit 12) are thermally connected. Have. For example, both conduits are placed in contact with or adjacent to each other. In the heat pump 10, the working fluid from the first and second heat radiating units 13 </ b> A and 13 </ b> B is hotter than the working fluid from the heat absorbing unit 11. In the regenerator 18, the working fluid from the first and second heat radiating parts 13 </ b> A and 13 </ b> B flowing through the bypass path 17 and the working fluid from the heat absorbing part 11 flowing through the main path 15 of the heat pump 10 exchange heat. By this heat exchange, the temperature of the working fluid in the bypass path 17 is lowered, and the temperature of the working fluid in the main path 15 is raised. The regenerator 18 can have a countercurrent heat exchange system in which a low-temperature fluid (working fluid in the main passage 15) and a high-temperature fluid (working fluid in the bypass passage 17) flow in opposition. Alternatively, the regenerator 18 may have a parallel flow type heat exchange system in which a high-temperature fluid and a low-temperature fluid flow in parallel.

  In the present embodiment, the heat pump 10 further includes an intermediate cooler 83 for cooling the working fluid flowing between the stages of the compressor 30. In the present embodiment, the intercooler 83 includes a pressure reducing valve (expansion valve) 84 that decompresses part of the working fluid from the second heat radiating part 13B, and a part of the working fluid from the second heat radiating part 13B. 84, a conduit 86 for storing the working fluid from the pressure reducing valve 84, a conduit 87 for guiding the working fluid from the gas phase portion in the tank 86 to the compression portion 12, and an expansion from the liquid phase portion in the tank 86. And a conduit 88 for guiding the working fluid to the section 14.

  In this embodiment, the inlet end of the conduit 85 is fluidly connected to the conduit of the bypass path 17. In another embodiment, the inlet end of the conduit 85 can be fluidly connected to the conduit between the heat radiating portions 13A, 13B and the third heat radiating portion 13E in the main path 15 of the heat pump 10. A flow rate control valve for controlling the bypass flow rate of the working fluid can be provided at the inlet of the conduit 85. In this embodiment, the outlet end of the conduit 85 is fluidly connected to the inlet of the pressure reducing valve 84. The outlet of the pressure reducing valve 84 is fluidly connected to the tank 86.

  The inlet end of conduit 87 is fluidly connected to the gas phase location of tank 86. The outlet end of the conduit 87 is fluidly connected between the stages between the first compression portion 12A and the second compression portion 12B. More specifically, the outlet end of the conduit 87 is fluidly connected to the vicinity of the inlet of the second compression portion 12B (between the first heat radiation portion 13A and the second compression portion 12B). The inlet end of the conduit 88 is fluidly connected to the liquid phase position of the tank 86. The outlet end of the conduit 88 is fluidly connected to or near the expansion portion 14.

  In the intercooler 83, part of the working fluid from the second heat radiating unit 13 </ b> B (second compression unit 12 </ b> B) flows through the conduit 85 toward the pressure reducing valve 84. In the pressure reducing valve 84, the working fluid is depressurized to a predetermined pressure. In the present embodiment, the working fluid is depressurized to a pressure substantially equal to the pressure in the interstage between the first compression unit 12A and the second compression unit 12B. The temperature of the decompressed working fluid drops. For example, the fluid temperature at the inlet of the pressure reducing valve 84 is about 102 ° C., and the fluid temperature at the outlet is about 70 ° C. The above numerical values are examples for helping understanding, and the present invention is not limited to these. Saturated liquid (liquid phase) and saturated vapor (gas phase) are stored in the tank 86.

  Here, in the present embodiment, the expansion portion 14 includes a first expansion valve 14A and a second expansion valve 14B. 14 A of 1st expansion valves are arrange | positioned in the downstream position of the confluence | merging point of the working fluid from the 3rd thermal radiation part 13E, and the working fluid from the bypass path | route 17. FIG. The outlet pressure of the first expansion valve 14A is substantially the same as the outlet pressure of the pressure reducing valve 84 (that is, substantially the same as the pressure in the interstage between the first compressor 12A and the second compressor 12B). Degree). The second expansion valve 14B is disposed at a downstream position of the first expansion valve 14A. The outlet end of the conduit 88 of the intercooler 83 is fluidly connected to the conduit 14Z between the first expansion valve 14A and the second expansion valve 14B. In the conduit 14Z, the working fluid from the first expansion valve 14A and the saturated liquid from the intercooler 83 merge. The merged fluid enters the second expansion valve 14B. The second expansion valve 14B further depressurizes the fluid.

  In the intercooler 83, saturated steam flows from the tank 86 through the conduit 87 toward the stage of the compression unit 12. By supplying saturated steam between the stages of the compressing unit 12, the temperature of the working fluid flowing between the stages decreases. For example, the temperature of the working fluid from the first heat radiating unit 13A is about 102 ° C., and the temperature of the working fluid after the cooling fluid is introduced (the inlet temperature of the second compression unit 12B) is about 95 ° C. The above numerical values are examples for helping understanding, and the present invention is not limited to these. In multistage compressors, effective intercooling is advantageous for reducing compression power.

  The supply system 20 (evaporation unit) includes a heating unit 21, an evaporation unit 22, and, if necessary, a compressor 30 (a suction device), and a duct 23 that fluidly connects the evaporation unit 22 and the compressor 30. And a fluid drive unit (not shown) as necessary.

  The heating unit 21 includes a conduit that is thermally connected to the third heat radiating unit 13E of the heat pump 10 and through which water from a supply source (not shown) flows. A heat exchanger 41 (a warmer, a heat exchange device) is configured including the heating unit 21 and the third heat radiation unit 13E. That is, in the heat exchanger 41, a part of the conduit of the supply system 20 (heating unit 21) and a part of the conduit of the main path 15 of the heat pump 10 (third heat radiation unit 13E) are thermally connected. It has a configuration. The heat exchanger 41 can have a countercurrent heat exchange system in which a low-temperature fluid (water in the supply system 20) and a high-temperature fluid (working fluid in the heat pump 10) face each other. Alternatively, the heat exchanger 41 may have a parallel flow type heat exchange system in which a high-temperature fluid and a low-temperature fluid flow in parallel. In the present embodiment, various known heat exchange structures of the heat exchanger 41 can be employed. The conduit of the heating unit 21 and the conduit of the third heat radiating unit 13E are arranged in contact with or adjacent to each other. For example, the conduit of the third heat radiating portion 13E can be disposed on the outer peripheral surface or inside of the conduit of the warming portion 21. In the heating unit 21, the temperature of the water in the supply system 20 rises due to the heat transferred from the third heat radiating unit 13 </ b> E of the heat pump 10.

  The evaporation unit 22 includes a tank 47 that stores at least a liquid to-be-heated fluid (water), and a circulation conduit 48 that is fluidly connected to the tank 47. A deaeration tank (not shown) and a fluid drive unit (not shown) are arranged between the heating unit 21 and the tank 47 as necessary. The tank 47 can have a level sensor 50 for measuring the liquid level and a gas-liquid separator (not shown) as required.

  The tank 47 or the circulation conduit 48 is provided with a water supply port from the heating unit 21 and a steam discharge port. The inlet end and the outlet end of the circulation conduit 48 are each connected to a tank 47. The circulation conduit 48 includes a heated pipe 51 that is thermally connected to the first heat radiating portion 13A and the second heat radiating portion 13B of the heat pump 10, a pump (not shown), and a valve (not shown) as necessary. Have The pump may be omitted by utilizing thermal convection of the fluid to be heated (water) and / or differential pressure with the outside.

  In this embodiment, the heat exchanger 45 (heat exchange apparatus) is comprised including the to-be-heated tube 51, the 1st heat radiating part 13A, and the 2nd heat radiating part 13B. That is, in the heat exchanger 45, the first heat radiating part 13A and the second heat radiating part 13B of the heat pump 10 and the heated pipe 51 of the evaporation part 22 are thermally connected. Heat from the working fluid flowing through the first heat radiating portion 13 </ b> A and the second heat radiating portion 13 </ b> B is transferred to the water flowing through the heated pipe 51. The heat exchanger 45 can have a countercurrent heat exchange system in which a low-temperature fluid (water in the heated pipe 51) and a high-temperature fluid (working fluid in the heat pump 10) flow opposite to each other. Alternatively, the heat exchanger 41 may have a parallel flow type heat exchange system in which a high-temperature fluid and a low-temperature fluid flow in parallel. As the heat exchange structure of the heat exchanger 41, various known ones can be adopted. The conduit of the first heat radiating part 13A or the second heat radiating part 13B of the heat pump 10 and the heated pipe 51 are arranged in contact with or adjacent to each other. For example, the conduit of the first heat radiating part 13 </ b> A or the second heat radiating part 13 </ b> B of the heat pump 10 can be disposed on the outer peripheral surface or inside of the heated pipe 51.

  In the evaporation unit 22, the water whose temperature has increased in the heating unit 21 is supplied to the tank 47 through the supply port, and the water is stored in the tank 47 and the circulation conduit 48. The amount of water supplied to the tank 47 is controlled so that the liquid level in the tank 47 falls within a predetermined range. For example, the amount of water supplied to the tank 47 is controlled based on the measurement result of the level sensor 50.

  The tank 47 is fluidly connected to the compressor 30 via the duct 23. The internal space of the tank 47 is sucked by the compressor 30 through the discharge port of the tank 47 and the duct 23. Due to the suction action of the compressor 30, the internal space of the evaporator 22 is decompressed. At least a part of the water in the heated pipe 51 that has received heat evaporates.

  The compressor 30 is disposed on the supply system 20 and is disposed downstream of the tank 47. As the compressor 30, various compressors such as an axial flow compressor, a centrifugal compressor, a reciprocating compressor, and a rotary compressor are applied, and those suitable for vapor compression are used.

  The compressor 30 sucks the internal space of the tank 47, compresses the steam from the tank 47, and flows the pressurized steam downstream. That is, the steam in the tank 47 flows in the duct 23 toward the compressor 30 and is output to the outside. The thermal fluid (steam) from the steam generation system S1 is supplied to a predetermined external facility such as a food manufacturing facility, an electronic device manufacturing plant, other manufacturing facilities, a cooking facility, an air conditioning facility, and a power plant. In other embodiments, the compressor 30 may be omitted.

  In the compressor 30 and / or the supply system 20, a nozzle 35 that supplies water to the steam is disposed as necessary. The arrangement position of the nozzle 35 is, for example, an inlet and / or an outlet of the compressor 30. When the compressor 30 is a multistage type, the nozzle 35 can be disposed between the stages of the compressor 30. The compression ratio (pressure ratio) of the compressor 30 is set according to the specification of the steam generation system S1. The nozzle 35 and the liquid phase position of the tank 47 can be fluidly connected via a conduit 36. In this conduit configuration, the liquid in the tank 47 having a relatively high temperature is effectively used for supplying the nozzle 35. For discharging (spraying) the liquid from the nozzle 35, a power source such as a pump (not shown) may be used, or a pressure difference between the inlet and the outlet of the conduit 36 may be used.

  In the present embodiment, due to the suction action by the compressor 30, the internal space at the heating site by the heat pump 10 in the supply system 20, that is, the internal space of the tank 47 is decompressed. Control valves (such as a flow rate control valve, not shown) and the compressor 30 on the supply system 20 are controlled so that the internal pressure of the tank 47 becomes a negative pressure (negative pressure) lower than the atmospheric pressure. This control is performed based on a measurement result of a sensor (not shown) that measures the internal pressure of the tank 47, for example.

  Thus, in the present embodiment, the water in the supply system 20 becomes steam by heat transfer from the heat pump 10. First, in the heat exchanger 41, the temperature of the water in the supply system 20 rises to near the boiling point due to heat transfer from the third heat radiating portion 13E of the heat pump 10. Thereafter, in the heat exchanger 45, the water undergoes phase change and evaporates due to heat transfer from the first and second heat radiating portions 13A and 13B. Sensible heat heating of water is mainly performed in the heat exchanger 41 (heater), and latent heat heating of water is mainly performed in the heat exchanger 45. The apparatus configuration is optimized such that the heat exchanger 41 is in a form suitable for sensible heat exchange and the heat exchanger 45 is in a form suitable for latent heat exchange. Occurs.

  The energy efficiency of the boiler is generally about 0.7 to 0.8 (70 to 80%), whereas the coefficient of performance (COP) as the energy efficiency of the heat pump is generally 2.5 to 5. 0. In this embodiment, steam can be generated with higher energy efficiency because the heat pump has individual heating units corresponding to sensible heat exchange and latent heat exchange.

  In the present embodiment, the heat recovery mechanism 80 recovers excess heat of the working fluid. As described above, the heat recovery mechanism 80 includes the heat exchanger 41 (warming device) that warms the working fluid from the second heat radiating unit 13B to the water that is directed to the evaporation unit 22, and the second working fluid that is directed to the compression unit 12. The regenerator 18 warms the working fluid from the heat radiating unit 13B, and the intermediate cooler 83 that cools the working fluid flowing between the stages of the compression unit 12 with the working fluid from the second heat radiating unit 13B.

  In the present embodiment, the working fluid from the second heat radiating unit 13 </ b> B is distributed to the heat exchanger 41 (heater), the regenerator 18, and the intercooler 83. In each of the heat exchanger 41 (heater), the regenerator 18, and the intercooler 83, surplus heat of the working fluid is effectively used. The heat distribution of the working fluid from the second heat radiating unit 13B, that is, the flow distribution of the working fluid in the heat exchanger 41 (heater), the regenerator 18, and the intercooler 83 is determined by the specifications and heat of the steam generation system S1. It is set according to the balance. In the present embodiment, the necessary heat in the heat exchanger 41 and the regenerator 18 is determined first, and the remaining heat is used for the intercooler 83.

  FIG. 2 shows a comparative example of the steam generation system. The system of FIG. 2 has a configuration in which the intercooler 83 of the steam generation system S1 of FIG. 1 is omitted. By numerical calculation, it was confirmed that the COP of the system S1 of FIG. 1 was improved compared to the system of FIG. For example, when the input temperature of the heat exhaust heat from the cold heat supply device 90 to the heat absorption unit 11 is 35 ° C. and the working fluid is R134a, the COP improvement rate is about 3%. In particular, when the input temperature of the warm exhaust heat is relatively low, the intermediate cooler 83 may be able to effectively use the excess heat.

  3A and 3B are schematic views showing an example of a regulator 77 that adjusts the distribution of surplus heat in the steam generation system S1 of FIG. 3A and 3B, the regulator 77 is a flow rate control capable of adjusting the flow distribution of the working fluid from the second heat radiating unit 13B to the heater (heat exchanger 41), the regenerator 18, and the intercooler 83. Valves 75 and 76 are included. In FIG. 3A, information related to the amount of heat supplied from the outside supplied to the heat absorbing unit 11 (for example, information related to the temperature and / or flow rate of the heat medium supplied to the heat absorbing unit 11) is sent to the control device 70. The control device 70 controls the regulator 77 (flow rate control valves 75 and 76) based on at least the information. For example, the flow rate of the working fluid to the intercooler 83 changes according to the temperature of the warm exhaust heat supplied to the heat absorption unit 11. The information for heat distribution is not limited to the information from the heat absorption part 11, For example, other information, such as the information regarding steam temperature, can be used. In FIG. 3B, the controller 70 determines the required heat in the heat exchanger 41 (heater) and the regenerator 18, and adjusts the controller 77 (flow control valves 75 and 76) according to the determined required heat. Control. In the regulator 77, the working fluid having a flow rate corresponding to the necessary heat flows to the heat exchanger 41 and the regenerator 18, and the remaining working fluid flows to the intercooler 83. That is, the remaining amount of the heat used in the heat exchanger 41 (heater) and the regenerator 18 is used in the intermediate cooler 83 out of the total amount of heat of the heat medium output from the second heat radiating unit 13B. The heat distribution in the regulator 77 can optimize the heat balance of the steam generation system S1.

  Returning to FIG. 1, in this embodiment, part of the working fluid bypasses the heat exchanger 41 via the bypass path 17, so that the flow rate of the working fluid entering the heat exchanger 41 is optimized. This is advantageous in effectively using the retained heat of the working fluid.

  The working fluid flowing through the bypass path 17 exchanges heat with the working fluid from the heat absorbing section 11 flowing through the main path 15 of the heat pump 10 in the regenerator 18. By this heat exchange, the temperature of the working fluid in the bypass passage 17 is lowered (for example, about 38 ° C.), and the temperature of the working fluid in the main passage 15 of the heat pump 10 is raised (for example, about 94 ° C.). Due to the increase in the input temperature of the working fluid to the compression unit 12, the power of the compression unit 12 is reduced.

  Further, in the present embodiment, the working fluid in the bypass passage 17 whose temperature has dropped in the regenerator 18 is from the heat exchanger 41 (third heat radiating portion 13E) flowing in the main passage 15 of the heat pump 10 before the expansion portion 14. It merges with the working fluid. As described above, the output temperature of the working fluid from the heat exchanger 41 is set to be relatively low. By reducing the input temperature of the working fluid to the expansion section 14, the liquid-gas ratio of the working fluid is optimized, and as a result, the heat source outside the cycle in the heat absorbing section 11 (medium flowing through the heat radiating pipe 91 of the cold heat supply device 90). Effectively absorbs heat.

  In the present embodiment, the energy efficiency is also improved from the point that the compression unit 12 is a multistage type. That is, the heat of the heat radiating portions 13A and 13B between the stages of the multistage compression unit 12 is deprived, thereby suppressing the temperature rise of the working fluid in the compression process of the working fluid. Improvement and reduction of compressor power can be achieved. The number of repetitions of the temperature rise of the working fluid due to compression and the temperature drop of the working fluid in the heat radiating section (13A, 13B) between the stages (the number of reheating stages) is 2, 3, 4, 5, 6, 7 , 8, 9, or 10 or more. It is advantageous for improving energy efficiency that the number of stages of reheating is large within the range of restrictions on the apparatus configuration.

  In the present embodiment, the fact that the input temperature of the working fluid to the multistage compression unit 12 is increased by the regenerator 18 is also advantageous in reducing the power of the compression unit 12. Moreover, effective use of heat is also achieved from the point of heating water that is a fluid to be heated by using cooling of the heat radiation portions 13A and 13B between the stages.

  As described above, in the present embodiment, the working fluid used for the evaporation generation is used for heating water, regenerating the working fluid, and intermediate cooling, so that the heat can be effectively used.

  In the present embodiment, the water in the supply system 20 becomes steam having a relatively low pressure and low temperature due to heat transfer from the heat pump 10 (heat radiating portions 13A and 13B), and is relatively high pressure due to compression by the compressor 30. And it can be high temperature steam. That is, the water heated by the heat pump 10 is further heated by the compression by the compressor 30, whereby high-temperature steam can be generated.

FIG. 4 is a Ts diagram showing an example of a state change of the steam generation process in the steam generation system S1. As shown in FIG. 4, after the temperature rises, the water changes its phase while keeping the temperature constant. At this time, saturated steam d ₀ is generated in a state of negative pressure P ₀ which is lower than atmospheric pressure (P 1 = 1 atm = about 0.1 MPa). Temperature of saturated steam d ₀ is lower than the standard boiling point.

Next, the saturated steam d ₀ becomes relatively high-pressure and high-temperature steam (superheated steam e ₂ ) by compression by the compressor 30 (see FIG. 1). That is, the vapor rises in temperature with the compression. The pressure _{P 2} of the superheated steam _{e 2} is greater than atmospheric pressure, for example, 0.8 MPa.

For example, a saturated steam of about 160 ° C. can be obtained by cooling the superheated steam e _{2 of} 0.8 MPa under a constant pressure (dashed line a in FIG. 4). Similarly, saturated steam d ₁ of about 100 ° C. can be obtained by cooling superheated steam at atmospheric pressure (about 0.1 MPa) under constant pressure. The above numerical values are examples for understanding, and the present invention is not limited thereto.

  By directly mixing liquid water or hot water into the cooling from superheated steam to saturated steam, the volume of steam is increased. In this case, for example, water or hot water is supplied to the steam at the outlet of the compressor 30.

By optimizing the supply amount and timing of water or hot water, the change from the relatively low pressure and low temperature saturated steam d ₀ to the relatively high pressure and high temperature saturated steam d ₂ can be made more direct. For example, when an appropriate amount of water or hot water is supplied to the steam at the inlet of the compressor 30, the saturated steam d ₀ at the inlet of the compressor 30 changes to saturated steam d ₂ at the outlet of the compressor 30 (FIG. 4 dashed lines c ₁ (spray) and c ₂ (compression). Alternatively, when an appropriate amount of water or hot water is supplied to the steam for each stage of the compressor 30 in the middle of the compressor 30, the saturated steam d ₀ at the inlet of the compressor 30 becomes saturated steam at the outlet of the compressor 30. changes to d ₂ (dashed line b in FIG. 4). That is, by optimizing the combination of compression by the compressor 30 and cooling by water or warm water, steam close to a saturated state can be efficiently discharged from the compressor 30.

  Thus, in this embodiment, both saturated steam and superheated steam can be easily generated by sequential heating by the heat pump 10 and the compressor 30. That is, the steam generation system S1 is highly flexible with respect to the steam specifications.

  Moreover, in this embodiment, since the compressor 30 supplements a part of heating process for steam generation, the heat pump 10 is used with high COP. Therefore, the steam generation system S1 is expected to save primary energy as a whole.

  Next, a second embodiment of the present invention will be described with reference to the drawings.

  FIG. 5 is a schematic diagram showing a steam generation system S2 according to the second embodiment. In the following description, the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  As shown in FIG. 5, in this embodiment, the steam generation system S2 is different from the steam generation system S1 in FIG. 1, and the compression unit 12 has three stages. That is, the compression unit 12 has a three-stage compression structure including a first compression unit 12A, a second compression unit 12B, and a third compression unit 12C. The compression unit 12 can have a multiaxial compression structure in which the rotation speeds corresponding to the compression units 12A, 12B, and 12C are individually controlled. Alternatively, the compression unit 12 can have a coaxial compression structure. The compression ratio (pressure ratio) of the compression unit 12 is set according to the specification of the steam generation system S2.

  In the present embodiment, four heat radiating portions 13A, 13B, 13C, and 13E are substantially arranged in series along the flow direction of the working fluid. The heat radiating portion 13A is disposed between the compression portions 12A and 12B, the heat radiating portion 13B is disposed between the compression portions 12B and 12C, the heat radiating portion 13C is disposed at a downstream position of the compression portion 12C, and the heat radiating portion 13E. Is disposed downstream of the heat dissipating part 13C.

  The heating unit 21 includes a conduit disposed adjacent to the heat radiating unit 13E of the heat pump 10 and through which water from a supply source (not shown) flows. A heat exchanger 41 is configured including the heating unit 21 and the heat dissipation unit 13E. In the heating unit 21, the temperature of the water in the supply system 20 rises due to heat transfer from the heat radiating unit 13 </ b> E of the heat pump 10.

  The evaporation section 22 includes a tank 47 that stores at least a liquid fluid to be heated (water), and circulation conduits (first circulation conduit 48A, second circulation conduit 48B, and third circulation conduit 48C) that are fluidly connected to the tank 47. ). The tank 47 is provided with a water supply port from the heating unit 21 and a steam discharge port. The tank 47 includes a level sensor 50 that measures the liquid level and a gas-liquid separator (not shown) as necessary.

  In the present embodiment, each circulation conduit 48A, 48B, 48C is fluidly connected to one tank 47. That is, each inlet end and each outlet end of the circulation conduits 48 </ b> A to 48 </ b> C are fluidly connected to the tank 47. The number of circulation conduits is set according to the specification of the steam generation system S2, and is 2, 3, 4, 5, 6, 7, 8, 9, or 10 or more. 48 A of 1st circulation conduit | pipe has 51 A of to-be-heated pipe | tubes arrange | positioned adjacent to the thermal radiation part 13A of the heat pump 10, and a pump (not shown) as needed. Similarly, the 2nd circulation conduit 48B has the to-be-heated pipe | tube 51B arrange | positioned adjacent to the thermal radiation part 13B of the heat pump 10, and a pump (not shown) as needed. The third circulation conduit 48 </ b> C includes a heated pipe 51 </ b> C disposed adjacent to the heat radiating portion 13 </ b> C of the heat pump 10 and a pump (not shown) as necessary. In the present embodiment, the heated tubes 51 </ b> A to 51 </ b> C are fluidly connected to the tank 47 independently of each other. The heated pipes 51 </ b> A to 51 </ b> C are arranged in parallel to the tank 47 and the supply system 20. The pump may be omitted by utilizing thermal convection of the fluid to be heated (water) and / or differential pressure with the outside.

  A heat exchanger 42 is configured including the heated tube 51A and the heat radiating portion 13A. Similarly, the heat exchanger 43 is configured including the heated tube 51B and the heat radiating portion 13B. A heat exchanger 44 is configured including the heated tube 51C and the heat radiating portion 13C. The heat exchangers 42 to 44 have a counter-current heat exchange system in which a low-temperature fluid (water in the heated pipes 51A to 51C) and a high-temperature fluid (a working fluid in the heat pump 10) flow opposite to each other. Can do. The heat exchangers 42 to 44 may have a parallel flow type heat exchange system in which a high-temperature fluid and a low-temperature fluid flow in parallel. Various known heat exchange structures for the heat exchangers 42 to 44 can be employed. For example, the conduits of the heat radiating portions 13A, 13B, and 13C of the heat pump 10 can be disposed on the outer peripheral surface and inside of the heated tubes 51A, 51B, and 51C.

  In the evaporation unit 22, the water whose temperature has increased in the heating unit 21 is supplied to the tank 47 through the supply port, and water is stored in the tank 47 and the circulation conduits 48 </ b> A to 48 </ b> C. The amount of water supplied to the tank 47 is controlled so that the liquid level in the tank 47 falls within a predetermined range. The water in the heated pipes 51A to 51C is heated by heat transfer from the heat radiation portions 13A to 13C of the heat pump 10, and at least a part of the water evaporates. The tank 47 is fluidly connected to the compressor 30 via the duct 23. The internal space of the tank 47 is sucked by the compressor 30 through the discharge port of the tank 47 and the duct 23. The steam in the tank 47 flows in the duct 23 toward the compressor 30.

  In the present embodiment, the heat recovery mechanism 80 includes a heat exchanger 41 (a warmer) that warms the working fluid from the heat radiating unit 13C to water that is directed to the evaporation unit 22, and a working fluid that is directed to the compression unit 12 from the heat radiating unit 13C. A regenerator 18 that warms the working fluid, and an intermediate cooler 83 that cools the working fluid flowing between the stages of the compression unit 12 from the heat radiating unit 13C.

  In the present embodiment, the intercooler 83 includes two pressure reducing valves (expansion valves) 84A and 84B, a tank 86, and conduits 85, 87A, 87B, and 88.

  In this embodiment, the inlet end of the conduit 85 is fluidly connected to the conduit of the bypass path 17. In other embodiments, the inlet end of the conduit 85 can be fluidly connected to the conduit between the heat dissipating parts 13A, 13B, 13C and the heat dissipating part 13E in the main path 15 of the heat pump 10. A flow rate control valve for controlling the bypass flow rate of the working fluid can be provided at the inlet of the conduit 85. In the present embodiment, the outlet end of the conduit 85 is fluidly connected to the inlet portion of the pressure reducing valve 84B. The outlet of the pressure reducing valve 84B is fluidly connected to the tank 86B. Further, the inlet portion of another pressure reducing valve 84A is fluidly connected to the liquid phase position of the tank 86B, and the outlet portion of the pressure reducing valve 84A is fluidly connected to another tank 86A.

  The inlet end of conduit 87A is fluidly connected to the gas phase location of tank 86A. The outlet end of the conduit 87A is fluidly connected between the stages between the first compression portion 12A and the second compression portion 12B. More specifically, the outlet end of the conduit 87 is fluidly connected to the vicinity of the inlet of the second compression section 12B (between the heat radiation section 13A and the second compression section 12B). The inlet end of conduit 87B is fluidly connected to the gas phase location of tank 86B. The outlet end of the conduit 87B is fluidly connected between the stages between the second compression portion 12B and the third compression portion 12C. More specifically, the outlet end of the conduit 87B is fluidly connected to the vicinity of the inlet of the third compression portion 12C (between the heat dissipation portion 13B and the third compression portion 12C). The inlet end of conduit 88 is fluidly connected to the liquid phase position of tank 86A. The outlet end of the conduit 88 is fluidly connected to or near the expansion portion 14.

  In the intercooler 83 of FIG. 5, a part of the working fluid from the heat radiating portion 13C (third compression portion 12C) flows through the conduit 85 toward the pressure reducing valve 84B. In the pressure reducing valve 84B, the working fluid is reduced to a pressure substantially equal to the pressure in the interstage between the second compression portion 12B and the third compression portion 12C. The temperature of the decompressed working fluid drops. Saturated liquid (liquid phase) and saturated vapor (gas phase) are stored in the tank 86B. Further, the saturated liquid from the tank 86B enters the pressure reducing valve 84A. In the pressure reducing valve 84A, the working fluid is further reduced to a pressure substantially equal to the pressure in the interstage between the first compression portion 12A and the second compression portion 12B. The temperature of the decompressed working fluid drops. Saturated liquid (liquid phase) and saturated vapor (gas phase) are stored in the tank 86A.

  In the intercooler 83, saturated steam flows from the tanks 86 </ b> A and 86 </ b> B through the conduits 87 </ b> A and 87 </ b> B toward the two stages of the compression unit 12. By supplying saturated steam between the stages of the compressing unit 12, the temperature of the working fluid flowing between the stages decreases. In multistage compressors, effective intercooling is advantageous for reducing compression power.

  In the present embodiment, the working fluid from the heat radiating portion 13C is put into an intermediate cooler 83B corresponding to the high pressure side (rear side) stage. The drain of the intercooler 83B is further depressurized by the pressure reducing valve, and is put into the intercooler 83A corresponding to the low pressure side (front side) stage. The flow rate of the cooling fluid supplied from the tank 86A of the intermediate cooler 83A to the stage of the compression unit 12 (between the front stage) is between the stage of the compression unit 12 from the tank 86B of the intermediate cooler 83B (between the rear stage). ) Less than the flow rate of the cooling fluid supplied. In the intercooler 83, the cooling fluid is adjusted to a state suitable for a plurality of stages of the compression unit 12, thereby realizing effective intercooling.

  In the present embodiment, since the supply system 20 includes a plurality of heated tubes (evaporation tubes) 51A to 51C, energy efficiency can be improved. In the heated tube, the ratio of the gas (vapor) to the liquid increases along the direction of water flow, and the heat transfer rate may decrease as the generation of the vapor progresses. Within the tube, it is preferred that water be dominant as mass and volume. Since the supply system 20 includes the plurality of heated pipes 51A to 51C, heating of water with a high gas ratio is avoided, and as a result, a decrease in heat transfer coefficient associated with steam generation is suppressed. Also, if the length of the heated tube (evaporation tube) is increased in order to increase the heat exchange area, the pressure difference between the inlet and outlet of the tube increases, and the power required to flow water through the tube increases. there is a possibility. When the plurality of heated pipes (evaporation pipes) 51A to 51C are independent from each other, the differential pressure is small, and an increase in water transport power accompanying expansion of the heat exchange area is suppressed. The arrangement of the heated pipes 51A to 51C in parallel facilitates the realization of an independent piping configuration and is advantageous for simplification of the apparatus.

  In the present embodiment, the supply system 20 includes a plurality of independent heated pipes (evaporation pipes) 51A to 51C, thereby improving the heat balance control. In the heat pump 10, the state (pressure etc.) of a working medium differs between the thermal radiation parts 13A-13C. The multi-stage compression having the heat radiation portions 13A to 13C is achieved by individually controlling the flow rate per unit time of the water flowing through the plurality of heated tubes (evaporation tubes) 51A to 51C corresponding to the heat radiation portions 13A to 13C. The reheat control in the unit 12 is optimized.

  FIG. 6 shows an example of a configuration for controlling the flow rate of water in the heated pipe (evaporating pipe) 51A. The heat pump 10 is provided with a sensor 71 that measures the outlet temperature of the first heat radiating portion 13A corresponding to the heated tube 51A. The control device 70 controls the flow rate of water per unit time flowing through the heated pipe 51A via the pump 52A for the heated pipe 51A based on the measurement result of the sensor 71. Thereby, the exit temperature of the working medium in the first heat radiating portion 13A can be set to the target value. You may use the sensor 72 which measures the inlet_port | entrance temperature of 13 A of 1st thermal radiation parts. In FIG. 5, the other heated pipes 51B and 51C and the corresponding heat radiation portions 13B and 13C can adopt the same configuration.

  The numerical values used in the above description and the temperatures described in the drawings are examples, and the present invention is not limited thereto.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit of the present invention. The present invention is not limited by the above description, but only by the appended claims.

1 is a schematic diagram showing a steam generation system according to a first embodiment. It is the schematic which shows the comparative example of a steam production | generation system. It is a schematic diagram which shows an example of the adjuster which adjusts heat distribution. It is a schematic diagram which shows an example of the adjuster which adjusts heat distribution. It is a Ts diagram which shows an example of the state change of the water by a steam production | generation system. It is the schematic which shows the steam production | generation system concerning 2nd Embodiment. An example of the structure which controls the flow volume of the water in an evaporation pipe is shown.

Explanation of symbols

  S1, S2 ... Steam generation system, 10 ... Heat pump, 11 ... Endothermic part, 12, 12A, 12B, 12C ... Compression part, 13A, 13B, 13C, 13E ... Radiation part, 14 ... Expansion part, 14A, 14B ... Expansion valve , 15 ... main path, 17 ... bypass path, 18 ... regenerator, 20 ... supply system (evaporation unit), 21 ... heating unit, 22 ... evaporation unit, 23 ... duct, 30 ... compressor, 35 ... nozzle, 41 ... Heat exchanger (warmer), 42, 43, 44 ... Heat exchanger, 47 ... Tank, 70 ... Control device, 80 ... Heat recovery mechanism, 83, 83A, 83B ... Intermediate cooler, 84, 84A, 84B ... pressure reducing valve, 86, 86A, 86B ... tank.

Claims (9)

A heat pump through which the first fluid flows, the heat pump including a heat absorption part, a compression part, a heat radiation part, and an expansion part;
An evaporation unit through which a second fluid flows, the evaporation unit including an evaporation unit in which the second fluid that has received heat transferred from the first fluid evaporates;
A heater for warming the first fluid from the heat dissipating part to the second fluid going to the evaporation part, a regenerator for warming the first fluid from the heat dissipating part to the first fluid going to the compression part, and A heat recovery mechanism including an intermediate cooler that cools the first fluid flowing between the stages of the compression unit by the first fluid from the heat dissipation unit;
A steam generation system comprising: The compression unit includes a multistage compressor having a plurality of stages,
2. The steam generation system according to claim 1, wherein the intermediate cooler decompresses a part of the first fluid from the heat radiating unit and supplies the depressurized fluid between the stages of the compression unit.   The intermediate cooler includes a pressure reducing valve that depressurizes a part of the first fluid from the heat radiating part, a tank that stores the first fluid from the pressure reducing valve, and a compression from the gas phase part in the tank. The steam generation system according to claim 1, further comprising a conduit for guiding the first fluid to a section.   The steam generation system according to claim 3, wherein the pressure reducing valve depressurizes a part of the first fluid from the heat radiating unit according to a pressure in an interstage of the compression unit.   The expansion section includes a first expansion valve in which a fluid containing the working fluid from the heater and the working fluid from the regenerator expands, the working fluid from the first expansion valve, and the intermediate cooling. The steam generation system according to claim 1, further comprising a second expansion valve that expands fluid including fluid from the vessel.   The heat recovery mechanism further includes an adjuster for adjusting heat distribution of the first fluid from the heat radiating unit to the heater, the regenerator, and the intercooler. The steam generation system according to claim 5.   The steam generator system according to claim 6, wherein the adjuster adjusts the heat distribution according to at least one of a temperature and a flow rate of a heat medium supplied to the heat absorption unit of the heat pump.   The steam generation system according to claim 6, wherein the adjuster adjusts the heat distribution according to an amount of heat required in the heating unit and the regeneration unit.   The steam generation system according to any one of claims 1 to 8, further comprising a compressor that compresses the second fluid evaporated in the evaporation section.

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