JP6394896B2 - Steam generation system - Google Patents

Description

  The present invention relates to a steam generation system that generates steam using a heat pump.

  Conventionally, as shown in FIG. 2 of Patent Document 1 below, heat is pumped up from the exhausted water in the evaporator (evaporator 1) of the heat pump (10), and the water is heated and steamed in the condenser (condenser 3). A steam generation system is known in which the steam is taken out from the outlet (17) through the steam separator (16).

  In this type of steam generation system, if the water level in the condenser is raised too much, the can water is taken out together with the steam, reducing the dryness of the steam, while if the water level in the condenser is lowered too much, the circulation of the can water is reduced. The ratio (NCR) is low, scale (water hardness components are precipitated by combining with carbonate ions, silica, etc.) tends to adhere to the condenser, and the discharge pressure of the compressor becomes too high. There is also a risk that it will be impossible to drive. Therefore, how to control the water level in the condenser is important.

  As for the fuel-fired boiler, as shown in FIG. 1 of Patent Document 2 below, the water level in the can (20) is detected by the external water level detection means (50), and the water supply means ( 60) is known to control. In the invention described in Patent Document 2, a downpipe (84) having a built-in air / water separator in the upper header (24) and communicating the lower part in the upper header (24) and the lower header (22), and an external Control means (70) for controlling the water supply means (60) based on the water level detected by the water level detection means (50). When the detected water level of the external water level detection means (50) exceeds the first set water level, the control means (70) controls the water supply means (60) so that the water level in the can falls, and the detected water level If it becomes below the 2nd setting water level lower than a 1st setting water level, the 2nd control which controls a water supply means (60) so that a can body water level may rise is performed. Then, while the first set water level is set to the dryness limit water level, the second set water level is equal to or higher than the superheat limit water level, and the circulation ratio of can water through the downcomer pipe (84) (paragraph [0050 of Patent Document 2]. ]) Is set to a water level that is greater than or equal to the set value.

JP 58-40451 (Fig. 2) JP 2013-194950 A (FIG. 1, summary, claim 1)

  However, the water level control of a fuel-fired boiler as described in Patent Document 2 cannot be applied as it is to a heat pump steam generation system. In particular, by controlling the water supply means so as to maintain the set water level, at the time of starting the steam generation system, with steaming (in other words, with the start of boiling of water in the condenser), the stored water in the condenser Since the void content (the ratio occupied by bubbles) increases and the water level rises, the can water is taken out together with the steam, and the dryness of the steam is lowered. In addition, in the case of a heat pump steam generation system, the heat transfer surface is not likely to be overheated by the combustion gas as in a fuel-fired boiler, so the water level before steaming is set higher than at normal times (after steaming). There is no need.

  Accordingly, the problem to be solved by the present invention is to provide a heat pump type steam generation system capable of preventing a decrease in the degree of dryness of steam particularly accompanying steaming. It is another object of the present invention to provide a heat pump type steam generation system capable of appropriately maintaining the circulation ratio of can water to prevent a decrease in the dryness of steam and preventing the scale from adhering to the condenser. To do.

The present invention has been made to solve the above problems, and the invention according to claim 1 is characterized in that a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to circulate a refrigerant, and the condensation is performed. A heat pump for exchanging heat between the refrigerant and the stored water in the condenser, heating the stored water to generate steam, and separating the steam-water mixture from the condenser into the steam and leading the steam to the outlet pipe An air / water separator for returning separated water to the condenser by a downpipe, a water level detector for detecting the water level in the air / water separator and / or the downpipe, and the downpipe or the air / water separator. and water supply means for supplying water to the condenser via either drained from the condenser through the downcomer or the steam-water separator, effluent from the condenser without passing through the downcomer or the steam-water separator and blowing means for said water supply means and the blanking And a control means for controlling over means, and wherein, during operation of the heat pump, the water level of (i) the condenser electromotive蒸前, the steam-water separator and / or the downcomer Controlling the water supply means and the blow means based on the detection signal of the water level detector so as to maintain the first set water level, and (ii) in the steam separator after steaming of the condenser and / or Controlling the water supply means and the blow means based on the detection signal of the water level detector so as to maintain the water level in the downcomer at a second set water level higher than the first set water level; or by the downcomer The steam generation system is characterized in that the water supply means and the blow means are controlled so as to maintain a circulation ratio of can water at a set value .

According to the first aspect of the present invention, not only the water supply means but also the blow means are controlled so as to maintain the water level in the steam separator and the downcomer at the set water level. When the water in the condenser increases (the ratio of bubbles) and the water level rises as the water level rises (with the start of boiling of the water in the vessel) Can be maintained as desired. At this time, the water level detector detects the water level in the air / water separator and the downcomer, not the condenser itself, so that the influence of boiling can be suppressed and the water level can be easily and reliably monitored .

According to the invention described in claim 1, the first setting level of the electromotive蒸前, by setting lower than the second set level of force蒸後, the stored water in the condenser with the Okoshi蒸Even if the void content increases and the water level rises, steam having a desired dryness can be derived. At this time, the second set water level after steaming is set to a water level at which a predetermined dryness can be obtained, and the first set water level before steaming is accompanied by steaming (that is, with the start of boiling of the stored water). ) It is preferable that the water level is set to the second set water level. Thereby, it is not necessary to drain by a blow means with steaming. In other words, the control means can be configured to be sufficient to control the water supply means based on the detection signal of the water level detector. In the case of a heat pump steam generation system, the heat transfer surface is unlikely to be overheated by combustion gas as in a fuel-fired boiler, so the first set water level before steaming is higher than the second set water level after steaming. Even if it is set to a low value, there is no inconvenience.

According to the first aspect of the present invention, after steaming, by controlling so that the circulation ratio of the can water is maintained at a set value, while maintaining the steam dryness as desired, Scale adhesion can be prevented.

Furthermore, the invention according to claim 2 is characterized in that the control means, after the steaming of the condenser, the water temperature (T1) of the water supplied by the water supply means, the water temperature of the separated water separated by the water separator ( The steam generation system according to claim 1 , wherein the circulation ratio is monitored based on T2) or steam pressure (P) and a return water temperature (T3) to the condenser by the downcomer. .

According to the second aspect of the present invention, the circulation ratio can be easily monitored and controlled based on the temperature or pressure at a predetermined location.

  According to the steam generation system of the present invention, it is possible to prevent a decrease in the dryness of steam accompanying steaming. In addition, the circulation ratio of can water can be properly maintained to prevent a decrease in the dryness of the steam and to prevent the scale from adhering to the condenser.

It is the schematic which shows the steam generation system of one Example of this invention.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram showing a steam generation system 1 according to an embodiment of the present invention.

  The steam generation system 1 according to the present embodiment includes a vapor compression heat pump 2. In the heat pump 2, the compressor 3, the condenser 4, the expansion valve 5, and the evaporator 6 are sequentially connected in an annular manner to circulate the refrigerant. Although details will be described later, the heat pump 2 heat-exchanges the refrigerant and the stored water in the condenser 4 to heat the stored water to generate steam.

  The steam generation system 1 further supplies an air / water separator 7 that separates the air / water mixture from the condenser 4 into an air / water separator, a water level detector 8 that detects the water level in the air / water separator 7, and the condenser 4. A water supply means 9 for supplying water, a blow means 10 for discharging water from the condenser 4, and a control means (not shown) for controlling the means 9 and 10 based on a detection signal of the water level detector 8 and the like are provided.

  The heat pump 2 is constituted by a single stage heat pump in this embodiment. Specifically, as described above, the compressor 3, the condenser 4, the expansion valve 5, and the evaporator 6 are sequentially connected in an annular manner to circulate the refrigerant. Of these, the compressor 3 compresses the gas refrigerant to a high temperature and a high pressure. The condenser 4 condenses the gas refrigerant from the compressor 3. Furthermore, the expansion valve 5 allows the liquid refrigerant from the condenser 4 to pass therethrough, thereby reducing the pressure and temperature of the refrigerant. The evaporator 6 evaporates the refrigerant from the expansion valve 5. In some cases, a capillary tube or the like can be used as the expansion valve 5.

  In the heat pump 2, in the evaporator 6, the refrigerant takes heat from the outside and vaporizes, while in the condenser 4, the refrigerant dissipates heat to the outside and liquefies. Using this, the heat pump 2 draws heat from the heat source fluid in the evaporator 6 and heats water in the condenser 4 to generate steam.

  The condenser 4 is an indirect heat exchanger that exchanges heat without mixing the refrigerant of the heat pump 2 and the stored water. In the present embodiment, the condenser 4 stores water halfway, and the stored water is heated by the refrigerant and vaporized. The steam is sent to various steam use facilities (not shown) via the steam separator 7.

  The evaporator 6 is an indirect heat exchanger that exchanges heat without mixing the refrigerant of the heat pump 2 and the heat source fluid. The heat source fluid is not particularly limited. For example, drain from steam using equipment, exhaust gas from combustion equipment, exhaust hot water discharged from a factory, or hot compressed air from an oil-free compressor or its cooling water Used.

  In the circuit of the heat pump 2, an oil separator is installed on the outlet side of the compressor 3, a liquid receiver is installed on the outlet side of the condenser 4, or an accumulator is installed on the inlet side of the compressor 3 as desired. Or a liquid gas heat exchanger that exchanges heat without mixing the refrigerant from the condenser 4 to the expansion valve 5 and the refrigerant from the evaporator 6 to the compressor 3 may be installed. In addition, an indirect heat exchanger between the refrigerant from the condenser 4 to the expansion valve 5 of the heat pump 2 and the feed water to the condenser 4 is installed as a refrigerant supercooler, or the heat pump 2 is evaporated as a refrigerant superheater. An indirect heat exchanger between the refrigerant from the vessel 6 to the compressor 3 and the heat source fluid may be installed.

  The steam separator 7 separates the steam / water mixture (wet steam) introduced from the condenser 4 through the inlet pipe 11 into the outlet pipe 12 while separating the steam with improved dryness into the outlet pipe 12. The separated water is returned to the condenser 4 by the downcomer 13. In the present embodiment, the centrifugal steam-water separator 7 has a cylindrical barrel 14 in the vertical direction, and through an inlet pipe 11 connected tangentially to the peripheral side wall of the barrel 14, An air / water mixture is introduced into the barrel 14 from the upper part of the condenser 4. The air-water mixture introduced into the body 14 swirls within the body 14, and the centrifugal force causes water droplets to hit the peripheral side wall of the body 14 and drop downward, and thus the steam with improved dryness is obtained. It is led out from the outlet pipe 12 connected to the upper part of the barrel 14. The outlet pipe 12 is provided with a check valve 15. On the other hand, the lower part of the trunk 14 is connected to the lower part (water storage part) of the condenser 4 via the downcomer 13.

  In this embodiment, the water level detector 8 detects the water level in the steam / water separator 7. However, the water level detector 8 may detect the water level in the downcomer 13 or the water level in a region straddling the steam-water separator 7 and the downcomer 13 depending on circumstances.

  The configuration of the water level detector 8 is not particularly limited. In the present embodiment, the water level detector 8 is an analog water level detector that can obtain an output corresponding to the water level. For example, an electrostatic capacity type water level detector is used, and the water level in the steam separator 7 is continuously detected. However, the water level detector 8 is not limited to such an analog type, and an electrode type water level detector or the like may be used depending on circumstances. In the case of an electrode-type water level detector, depending on the number of water levels to be detected, the presence or absence of a water level at the lower end can be determined by using one or more electrode rods, depending on whether the water level is below the lower end of each electrode rod. To detect.

  In the illustrated example, the water level detector 8 includes a water level detection tube 16 outside the body 14 of the air / water separator 7, and a water level detection rod (electrode rod) 17 is inserted into the water level detection tube 16 to electrostatically A capacitive (or electrode type) water level detector is configured. The water level detection cylinder 16 has an upper end connected to the upper part of the trunk 14 of the steam separator 7 through the upper communication pipe 18, and a lower end connected to the downcomer pipe 13 through the lower communication pipe 19. ing.

  The water supply means 9 is means for supplying water to the lower part (water storage part) of the condenser 4. At this time, the water supply means 9 may supply water to the condenser 4 via the downcomer 13 or the air / water separator 7, or directly to the condenser 4 without going through the downcomer 13 or the air / water separator 7. You may supply water. In particular, when the third control described later is performed, the water supply means 9 is a means for supplying water to the condenser 4 via the downcomer 13 or the steam separator 7.

  The water supply means 9 includes a water pipe 20 to the downcomer 13 or the steam separator 7 or the condenser 4. In the illustrated example, the water supply channel 20 is connected to the lower part of the downcomer pipe 13 (its vertical pipe part). In this case, the water supplied from the water supply channel 20 is also supplied to the condenser 4 via the downcomer 13. A water supply pump 21 and a check valve 22 are sequentially provided in the water supply path 20 toward the downstream side. By operating the water supply pump 21, water can be supplied to the downcomer 13 and the condenser 4. The feed water pump 21 is controlled to be turned on / off. In some cases, the rotational speed is controlled by an inverter or, instead of performing such inverter control, an electric valve is provided in the feed water channel 20 to adjust its opening degree. By doing so, it is good also as adjustment of a water supply flow volume.

  The blow means 10 is means for draining from the lower part (water storage part) of the condenser 4. At this time, the blowing means 10 may drain from the condenser 4 through the downcomer 13 or the steam separator 7, or directly from the condenser 4 without going through the downcomer 13 or the steam separator 7. You may drain.

  The blow means 10 includes a drainage pipe 23 from the downcomer 13 or the steam separator 7 or the condenser 4. In the illustrated example, the drainage channel 23 is connected to the lower part of the downcomer 13 (the vertical pipe). In this case, the stored water in the condenser 4 is also drained into the drainage channel 23 via the downcomer 13. A drain valve 24 is provided in the drain channel 23. By opening the drain valve 24, the drainage pipe 13 and the condenser 4 can be drained. The drain valve 24 is on / off controlled, but the drain flow rate may be adjustable by adjusting the opening degree in some cases.

  In addition, the steam generation system 1 of the present embodiment is provided with various sensors for monitoring the steam pressure, the water temperature, and the like as desired. In the illustrated example, in addition to the pressure sensor 25, a first temperature sensor 26, a second temperature sensor 27, and a third temperature sensor 28 are provided.

  The pressure sensor 25 detects the pressure P of the generated steam. In the illustrated example, a pressure sensor 25 is provided on the upstream side of the check valve 15 in the outlet pipe 12 from the steam / water separator 7.

The first temperature sensor 26 detects the water temperature T ₁ of the water supplied by the water supply means 9. In the illustrated example, a first temperature sensor 26 is provided in the water supply channel 20 on the upstream side of the check valve 22.

The second temperature sensor 27 detects the water temperature T ₂ of the separated water that has been separated into the steam by the steam separator 7. In the illustrated example, a second temperature sensor 27 is provided in the upper part of the downcomer 13 (the outlet side of the steam separator 7).

The third temperature sensor 28 detects the return water temperature T ₃ to the condenser 4 by the downcomer 13. In the illustrated example, a third temperature sensor 28 is provided below the downcomer 13 (on the inlet side to the condenser 4).

  However, which sensor is installed (or used) is changed according to the type of control described later. In particular, when performing the third control described later, it is preferable to install each of the temperature sensors 26 to 28 (however, the pressure sensor 25 may be used instead of or in addition to the second temperature sensor 27). In the case of this control, it is not always necessary to install the sensors 25-28.

  Further, a sensor other than these may be installed. For example, a fourth temperature sensor (not shown) for detecting the temperature of the heat source fluid on the outlet side of the evaporator 6 is provided in the heat source fluid passage 29 through which the heat source fluid is passed. May be provided. Further, as will be described later, a sensor for detecting steaming from the condenser 4 (that is, generation of steam due to the start of boiling of the stored water), a sensor for detecting the water temperature of the stored water in the condenser 4, etc. You may provide separately from 25-28.

  The control means is a controller (not shown) that controls the water supply means 9, the blow means 10, and the like based on the detection signals of the sensors 25 to 28. Specifically, the controller includes the water level detector 8 and, if desired, the pressure sensor 25 and the temperature sensors 26 to 28, in addition to these sensors, the heat pump 2 (particularly the compressor 3), the water supply pump. 21 and the drain valve 24, etc., and executes various controls as described below. Here, one or more of the first control, the second control, and the third control can be executed.

  In the following, an example in which the water level in the steam separator 7 is monitored and controlled is shown, but as described above, the downcomer 13 instead of or in addition to the water level in the steam separator 7. In some cases, the water level in the inside is monitored and controlled. Considering the decrease in dryness when the water level is raised and the possibility of scale adhering to the condenser 4 due to the reduction in the circulation ratio when the water level is lowered, the set water level as the control target water level The water level detector 8 is provided according to the set water level.

  In the following, the term “steaming” refers to the start of boiling of the stored water in the condenser 4, and the fact that steaming has been reached is the pressure in the condenser 4, the water temperature in the condenser 4, or the inside of the condenser 4. It can be detected by both the pressure and the water temperature in the condenser 4. When there is air in the steam separator 7 or the condenser 4 at the time of water supply before steaming, the pressure increases due to the water supply. Therefore, the accuracy can be determined by using both the pressure in the condenser 4 and the water temperature. It is possible to detect fumigation well. However, the first control can be controlled without particularly detecting steaming. The pressure in the condenser 4 can be detected by the pressure sensor 25, and the water temperature in the condenser 4 may be estimated by the third temperature sensor 28 or the second temperature sensor 27, or the condenser 4 may be detected by a temperature sensor provided separately.

≪First control≫
In the first control, during the operation of the heat pump 2, before and after steaming from the condenser 4, the water level in the steam separator 7 is set to the set water level (corresponding to the second set water level H2 of the second control described later). The water supply means 9 and the blow means 10 are controlled based on the detection signal of the water level detector 8 so that the water level is maintained. In order to raise the water level, water may be supplied by the water supply means 9, and conversely, in order to lower the water level, the water is drained by the blow means 10, or water supply by the water supply means 9 is stopped if steam is being generated, or by the water supply means 9 What is necessary is just to reduce water supply flow volume.

  The first control will be described in detail. First, when the steam generation system 1 is started, before steam is generated from the condenser 4 (in other words, before the start of boiling of water in the condenser 4), the water level is detected. Water is supplied by the water supply means 9 until the device 8 detects the set water level (H2), and the stored water in the condenser 4 is heated by the heat pump 2.

  The heat pump 2 operates by operating the compressor 3. How to operate the heat pump 2 is not particularly limited. For example, the motor of the compressor 3 may be rotated at a constant speed, or the rotational speed of the motor of the compressor 3 may be inverter controlled so that the heat source fluid temperature on the outlet side of the evaporator 6 becomes a predetermined temperature. Good. Alternatively, the compressor 3 may be subjected to on / off control or inverter control so that the obtained steam has a predetermined pressure.

  Accompanying the operation of the heat pump 2, the temperature of the stored water in the condenser 4 rises, eventually boils and evaporates. With steaming (in other words, with the start of boiling of water in the condenser 4), the void content (the ratio of bubbles) in the condenser 4 increases and the water level tends to rise. Normally, the water level in the steam separator 7 is maintained at the set water level (H2) by draining with the blow means 10.

  A steam having a predetermined pressure is led out from the outlet pipe 12 of the steam separator 7. If the water level in the steam separator 7 decreases with the generation of steam, water is supplied by the water supply means 9, and the water level in the steam separator 7 is maintained at the set water level (H2). That is, in the first control, typically, immediately after steaming (at the start of boiling), the set water level (H2) is maintained by drainage by the blowing means 10, but thereafter, without using the blowing means 10, Water can be maintained at the set water level (H2) by supplying water by the water supply means 9 by the amount of water level drop accompanying steam generation.

  In particular, in the case where the water level detector 8 is an electrode-type water level detector that detects the presence or absence of a water level at the lower end of the electrode rod, between the stop of water supply accompanying the rise in water level and the start of water supply accompanying the water level fall. Of course, an appropriate differential (operation gap) may be provided. For example, when the water level rises, the water supply may be stopped when the water level detector 8 detects the water level. On the other hand, when the water level falls, the water supply may be started when a set time elapses after the water level detector 8 no longer detects the water level. Of course, the same control as this may be performed using two electrode rods having different heights at the lower end, and in that case, when the upper electrode rod detects the water level, the water supply is stopped, When the lower electrode rod no longer detects the water level, water supply is started. On the other hand, in particular, when the water level detector 8 is a capacitance type water level detector capable of continuously detecting the water level, the water supply pump 21 is maintained at the set water level (H2) in addition to the on / off control as described above. As described above, the rotational speed of the feed water pump 21 may be inverter-controlled using a PID algorithm or the like.

  According to the first control, the dryness of the steam can be maintained as desired by maintaining the water level in the steam separator 7 at the set water level (H2). Since the water level detector 8 detects not the condenser 4 itself but the water level in the steam separator 7, the influence of boiling can be suppressed and the water level can be monitored easily and reliably. Moreover, water level control can be easily performed by not changing the set water level before and after steaming.

≪Second control≫
Since the second control is basically the same as the first control, the description will focus on the differences between them, and the description of the same parts will be omitted.

  In the second control, the set water level is set to different water levels before and after steaming from the condenser 4. Specifically, a first set water level H1 before steaming and a second set water level H2 after steaming are set, and the first set water level H1 is set lower than the second set water level H2. . If the first set water level H1 is too low, the discharge pressure of the compressor 3 becomes too high and the heat pump 2 may not be operated. Therefore, the first set water level H1 is defined within a range where this can be prevented. On the other hand, the second set water level H2 is set to a water level at which the degree of dryness of the steam can be a predetermined value or more.

  In the second control, first, when the steam generation system 1 is started, before the steam is generated from the condenser 4 (in other words, before the boiling of water in the condenser 4 starts), the water level detector 8 is the first. Water is supplied by the water supply means 9 until the set water level H1 is detected, and the stored water in the condenser 4 is heated by the heat pump 2.

  Accompanying the operation of the heat pump 2, the temperature of the stored water in the condenser 4 rises, eventually boils and evaporates. With steaming (in other words, with the start of boiling of water in the condenser 4), the void content (the ratio of bubbles) in the condenser 4 increases and the water level tends to rise. The control target water level is switched from the first set water level H1 to the second set water level H2. At this time, it is preferable to determine each set water level so that the control can be performed with the second set water level H2 as the target water level without draining by the blowing means 10.

  And after steaming (after the start of boiling), the water supply means 9 is basically controlled so as to maintain the second set water level H2. As described above, in the second control, immediately after steaming (at the start of boiling), it is possible to cope without draining by the blowing means 10, and thereafter, basically without using the blowing means 10, steam generation is possible. The set water level can be maintained by supplying water by the water supply means 9 by the amount corresponding to the decrease in the water level. In other words, the control means can be configured to be sufficient only to control the water supply means 9 based on the detection signal of the water level detector 8.

  According to the second control, by setting the first set water level H1 before steaming to be lower than the second set water level H2 after steaming, the voids of the stored water in the condenser 4 accompanying steaming Even if the minute increases and the water level rises, steam with a desired dryness can be derived. At this time, the second set water level H2 after the steaming is set to a water level at which a predetermined dryness can be obtained, and the first set water level H1 before the steaming is accompanied by steaming (that is, stored) as described above. It is preferable that the water level be set to the second set water level H2 (with the start of boiling of water). Thereby, it is not necessary to drain by the blow means 10 with steaming, and energy saving can be achieved.

≪Third control≫
Since the third control is basically the same as the first control (or the second control), the description will focus on the differences between them, and the description of the same parts will be omitted.

  In the third control, before steaming from the condenser 4, the water level in the steam separator 7 is maintained at the set water level (the first set water level H1 or the second set water level H2), while the can by the downcomer 13 The water supply means 9 and the blow means 10 are controlled so as to maintain the water circulation ratio at the set value. In other words, control is performed based on the water level until steaming, whereas control is performed based on the circulation ratio rather than the water level after steaming. However, it is preferable that the water level in the steam separator 7 is controlled to the second set water level H2 as the upper limit from the viewpoint of maintaining the dryness at a predetermined level or higher during the control after the steaming.

  The circulation ratio is defined by (evaporation + precipitation) / (water supply). The amount of evaporation is the amount of steam outflow from the steam separator 7, and the amount of precipitation is the amount of can water (circulated water) flowing down through the downcomer 13. Here, during steady state, the amount of evaporation is equal to the amount of water supplied, and the circulation ratio increases as precipitation increases.

The circulation ratio will be described more specifically. The feed water flow rate to the precipitation pipe 13 through the feed water channel 20 is G ₁ (water temperature T ₁ ), and the flow rate from the steam separator 7 to the precipitation pipe 13 is G ₂ (steam Saturation temperature T ₂ ), G ₃ (water temperature T ₃ ) and the flow rate from the downcomer 13 to the condenser 4 (flow rate after the combined water supply) and C _p are the constant-pressure specific heat of the can water, The following equation holds.

[Number _{1] C p G 1 T 1} + C p G 2 T 2 = C p G 3 T 3

Here, when the relationship of G ₃ = G ₁ + G ₂ is used, the following relational expression is derived as the circulation ratio.

[Equation 2] Circulation ratio = (G ₁ + G ₂ ) / G ₁ = (T ₂ −T ₁ ) / (T ₂ −T ₃ )

That is, the temperature of the water supplied by the water supply means 9 (that is, the detected temperature of the first temperature sensor 26) T ₁ , and the temperature of the separated water separated by the steam separator 7 (that is, the detected temperature of the second temperature sensor 27) T _2. , and based on the T ₃ (the temperature detected by the words third temperature sensor 28) downcomer 13 to the condenser 4 by the return water temperature, can be monitored circulation ratio. However, the saturated steam, since the temperature and pressure is in a predetermined relationship, instead of the T ₂ (the temperature detected by the words second temperature sensor 27) the gas-water separator 7 by the steam-water separated separated water temperature The pressure of the steam in the steam separator 7 (that is, the detected pressure of the pressure sensor 25) P can be monitored, and the circulation ratio can be obtained based on the monitored pressure.

  In any case, according to the third control, the circulation ratio can be easily monitored and controlled based on the temperature or pressure at a predetermined location. Specifically, the water supply means 9 and the blow means 10 are controlled so as to maintain the circulation ratio at the set value. If the circulation ratio decreases, control is performed to increase the water level, while if the circulation ratio increases, control is performed to decrease the water level. Similarly to the above-described controls, the water level may be raised by the water supply means 9, and conversely, the water level may be lowered by draining by the blow means 10, stopping the water supply by the water supply means 9, What is necessary is just to reduce the feed water flow rate by the means 9.

  Of course, in addition to grasping and controlling the circulation ratio based on the temperature and pressure at each location, the water supply and / or evaporation and precipitation are detected by a flow meter, and the circulation is based on these detected flow rates. The ratio may be grasped and controlled.

  The steam generation system 1 of the present invention is not limited to the configuration (including control) of the above embodiment, and can be changed as appropriate. In particular, the heat pump 2 that heats the stored water in the condenser 4 to generate steam, the steam / water separator 7 that separates the steam / water mixture from the condenser 4, and / or the steam / water separator 7. A water level detector 8 for detecting the water level in the downcomer 13, a water supply means 9 for supplying water directly or indirectly to the condenser 4, a blow means 10 for draining directly or indirectly from the condenser 4, and these means The control means sets the water level in the steam separator 7 and / or the downcomer pipe 13 before and / or after steaming from the condenser 4 during operation of the heat pump 2. If the water supply means 9 and / or the blow means 10 are controlled so as to maintain the water level, other configurations can be appropriately changed.

  For example, although the steam / water separator 7 is provided separately from the condenser 4 in the above embodiment, the steam / water separator 7 may be integrally provided on the top of the condenser 4 according to circumstances. For example, although the can described in Patent Document 2 described above can be said to be a heat exchanger for combustion gas and water, it may be used as a condenser 4 by using this as a heat exchanger for refrigerant and water. In the case of such a configuration, the body 14 of the steam / water separator 7 has a lower portion communicating with the water storage section of the condenser 4, and an appropriate baffle plate that separates steam from the water storage section into the water within the body 14. Is provided, and the steam with improved dryness is led out from above. The lower part of the trunk 14 and the lower part of the condenser 4 are connected by a downcomer 13. The water level detector 8 usually detects the water level of the downcomer 13.

  Moreover, in the said Example, although the waste_water | drain by the blow means 10 was thrown away outside, the waste_water | drain was stored in the tank, and the stored water in the said tank has priority over the water supply by the next water supply means 9. May be supplied.

  Furthermore, the heat pump 2 is not limited to a single stage and can be a plurality of stages. When the heat pump 2 has a plurality of stages, adjacent stage heat pumps may be connected using an indirect heat exchanger, or may be connected using a direct heat exchanger (intercooler). In the latter case, an intermediate cooler that receives the refrigerant from the compressor of the low-stage (low-temperature side) heat pump and the refrigerant from the expansion valve of the high-stage (high-temperature side) heat pump and directly contacts both refrigerants to exchange heat. The intermediate cooler is a condenser of a low-stage heat pump and an evaporator of a high-stage heat pump. As described above, the multi-stage (multi-stage) heat pump includes a single-stage multi-stage heat pump, a multi-element (multi-element) heat pump, or a combination thereof. When the heat pump 2 has a plurality of stages, typically, the lowest stage evaporator 6 draws heat from the heat source fluid, and the highest stage condenser 4 heats the stored water to generate steam.

DESCRIPTION OF SYMBOLS 1 Steam generation system 2 Heat pump 3 Compressor 4 Condenser 5 Expansion valve 6 Evaporator 7 Air-water separator 8 Water level detector 9 Water supply means 10 Blow means 11 Inlet pipe 12 Outlet pipe 13 Precipitation pipe 14 Body 15 Check valve 16 Water level Detection cylinder 17 Water level detection rod 18 Upper communication pipe 19 Lower communication pipe 20 Water supply path 21 Water supply pump 22 Check valve 23 Drainage path 24 Drainage valve 25 Pressure sensor 26 First temperature sensor 27 Second temperature sensor 28 Third temperature sensor 29 Heat source Fluid path H1 First set water level H2 Second set water level

Claims (2)

A compressor, a condenser, an expansion valve, and an evaporator that are sequentially connected in an annular manner to circulate the refrigerant, heat exchange between the refrigerant and the stored water in the condenser, and heat the stored water to generate steam; ,
An air-water separator that separates the air-water mixture from the condenser and discharges steam to an outlet pipe, while returning the separated water to the condenser via a downpipe; and
A water level detector for detecting the water level in the steam separator and / or the downcomer,
Water supply means for supplying water to the condenser via the downcomer or the steam separator ;
Blow means for draining from the condenser through the downcomer or the steam separator, or for draining from the condenser without going through the downcomer or the steam separator ,
Control means for controlling the water supply means and the blow means,
The control means, during operation of the heat pump ,
(I) Before the steaming of the condenser, the water supply means and the water supply means based on the detection signal of the water level detector so as to maintain the water level in the steam separator and / or the downcomer at the first set water level Control the blowing means ,
(Ii) detection of the water level detector so that the water level in the steam separator and / or the downcomer pipe is maintained at a second set water level higher than the first set water level after the condenser is steamed; Steam is controlled to control the water supply means and the blow means based on a signal; or to control the water supply means and the blow means so as to maintain a circulation ratio of can water by the downcomer at a set value. Generating system. The control means, after steaming of the condenser, water supply temperature (T1) by the water supply means, water temperature (T2) of the separated water separated by the steam separator, or steam pressure (P), and The steam generation system according to claim 1 , wherein the circulation ratio is monitored based on a return water temperature (T3) to the condenser by the downcomer.

Images