JP5633731B2 - Heat pump steam generator - Google Patents

Description

  The present invention relates to a heat pump-type steam generator that generates steam using a heat pump using waste hot water, air, exhaust gas, or the like as a heat source.

  Conventionally, as disclosed in Patent Document 1 below, in a heat exchanger (10) that is an evaporator, heat is absorbed from waste water of a factory or the like, and in a heat exchanger (5) that is a condenser, steam is absorbed. A heat pump type steam generator to be generated has been proposed. In this apparatus, the steam from the condenser is sent to steam using equipment after adjusting the steam pressure by a valve (14) provided in the steam delivery pipe (11).

JP 2010-38391 A

  However, in the prior art, the amount of generated steam cannot be adjusted according to the use load of the steam in the steam using facility. For this reason, if the amount of steam used in the steam-using facility increases, it becomes impossible to supply steam having a desired steam pressure. Conversely, if the amount of steam used in the steam-using facility decreases or disappears, the steam remains.

  In addition, although the amount of steam generated changes according to changes in the temperature and flow rate of the exhaust hot water serving as the heat source of the heat pump, it is not possible to stably supply steam to the steam-using equipment from this point.

  The problem to be solved by the present invention is to provide a heat pump type steam generator capable of coping with changes in the use load of steam. It is another object of the present invention to make it possible to stably supply steam to steam-using equipment even when the temperature of the heat source changes.

  According to the first aspect of the present invention, steam having a desired vapor pressure can be obtained by controlling the compressor based on the pressure of the steam generated by the condenser. Accordingly, it is possible to cope with a change in the use load of steam in the steam use facility. For example, if the amount of steam used in the steam-using facility increases, the steam pressure decreases, so the amount of steam generated by the heat pump can be increased. Conversely, if the amount of steam used in the steam-using facility decreases or disappears, the steam pressure increases. Therefore, it is only necessary to reduce or eliminate the amount of steam generated by the heat pump.

The invention described in claim 1 includes a heat pump in which a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to circulate the refrigerant, and in the condenser, the refrigerant and water are subjected to heat exchange. Steam is generated, and in the evaporator, the refrigerant and the fluid to be cooled are heat-exchanged to cool the fluid to be cooled, and the detected pressure of the pressure sensor that detects the pressure of the steam generated in the condenser is used. The compressor can be controlled based on the detected temperature of the temperature sensor provided on the outlet side of the cooled fluid flow path of the evaporator, and the compressor can be controlled based on the control by the pressure sensor. The compressor is controlled by switching between control by the temperature sensor, and based on the detected pressure of the pressure sensor, the first upper limit pressure and the first lower limit pressure are set in the range of the first upper limit pressure and the first lower limit pressure. Compressor Example control or PID control, or proportional control or PID control of the compressor within a range between a second upper limit temperature and a second lower limit temperature and using the second lower limit temperature as a set value based on the temperature detected by the temperature sensor Then, the first deviation rate and the second deviation rate are obtained by the following equations at the set timing, and the compressor is controlled with the smaller deviation rate of the control by the pressure sensor and the control by the temperature sensor. a feature and be Ruhi Toponpu steam generator.
First deviation rate = (first upper limit pressure−current pressure) / (first upper limit pressure−first lower limit pressure)
Second deviation rate = (current temperature−second lower limit temperature) / (second upper limit temperature−second lower limit temperature)

According to the invention described in claim 1 and claims 2 to 4 described later, it is possible to obtain steam having a desired vapor pressure by controlling the compressor based on the pressure of the steam generated in the condenser. it can. Accordingly, it is possible to cope with a change in the use load of steam in the steam use facility. For example, if the amount of steam used in the steam-using facility increases, the steam pressure decreases, so the amount of steam generated by the heat pump can be increased. Conversely, if the amount of steam used in the steam-using facility decreases or disappears, the steam pressure increases. Therefore, it is only necessary to reduce or eliminate the amount of steam generated by the heat pump.
Moreover, according to invention of Claim 1 and Claims 2-4 mentioned later, a vapor | steam can be produced | generated by raising the heat | fever of the to-be-cooled fluids, such as waste water discharged | emitted from a factory. Further, the compressor can be controlled based on the temperature of the fluid to be cooled after passing through the evaporator.
By the way, the smaller the deviation rate, the closer to the target value, the smaller the operation amount of the compressor. If an attempt is made to control the compressor with a larger deviation rate, that is, a larger manipulated variable, the smaller deviation rate, that is, the smaller manipulated variable, will soon reach the target value. However, according to the first aspect of the invention, the frequency at which the compressor stops can be reduced by appropriately switching to the control with the smaller deviation rate. Moreover, even if it stops, it can transfer to a stop state gradually. Furthermore, there is no need to manually set pressure control or temperature control.

The invention according to claim 2 includes a heat pump in which a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to circulate the refrigerant, and in the condenser, heat exchange is performed between the refrigerant and water. Steam is generated, and in the evaporator, the refrigerant and the fluid to be cooled are heat-exchanged to cool the fluid to be cooled, and the detected pressure of the pressure sensor that detects the pressure of the steam generated in the condenser is used. The compressor can be controlled based on the detected temperature of the temperature sensor provided on the outlet side of the cooled fluid flow path of the evaporator, and the compressor can be controlled based on the control by the pressure sensor. The compressor is controlled by switching between control by the temperature sensor, and based on the detected pressure of the pressure sensor, the first upper limit pressure and the first lower limit pressure are set in the range of the first upper limit pressure and the first lower limit pressure. Compressor Example control or PID control, or proportional control or PID control of the compressor within a range between a second upper limit temperature and a second lower limit temperature and using the second lower limit temperature as a set value based on the temperature detected by the temperature sensor Then, at the set timing, the operation amount of the compressor in the control by the pressure sensor and the operation amount of the compressor in the control by the temperature sensor are obtained, and the control amount by the pressure sensor and the control by the temperature sensor are determined. a to Ruhi Toponpu steam generator and wherein the controller controls the compressor in smaller operation amount.

If an attempt is made to control the compressor with a larger operation amount, the smaller operation amount will soon reach the target value. However, according to the second aspect of the invention, the frequency at which the compressor stops can be reduced by appropriately switching to the control with the smaller operation amount. Moreover, even if it stops, it can transfer to a stop state gradually. Furthermore, there is no need to manually set pressure control or temperature control.

The invention according to claim 3 is provided with a heat pump in which a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to circulate the refrigerant, and in the condenser, the refrigerant and water are subjected to heat exchange. Steam is generated, and in the evaporator, the refrigerant and the fluid to be cooled are heat-exchanged to cool the fluid to be cooled, and the detected pressure of the pressure sensor that detects the pressure of the steam generated in the condenser is used. The compressor can be controlled based on the detected temperature of the temperature sensor provided on the outlet side of the cooled fluid flow path of the evaporator, and the compressor can be controlled based on the control by the pressure sensor. wherein controlling the compressor by switching the control by the temperature sensor, comprising a plurality of stages of the heat pump, the evaporator of the lowermost heat pump, the refrigerant and the cooling fluid to the heat exchanger, the top of the heat pump In the compressor, steam is generated, and the compressor of the uppermost heat pump is set in a range between the first upper limit pressure and the first lower limit pressure based on the detected pressure of the pressure sensor, with the first upper limit pressure as a set value. Proportional control or PID control, or based on the temperature detected by the temperature sensor, the range of the second upper limit temperature and the second lower limit temperature, and the second lower limit temperature as a set value, the lowermost heat pump compressor is proportional When controlling or PID control and controlling the compressor of the uppermost heat pump based on the pressure detected by the pressure sensor, the compressor of each lower heat pump is connected to the condenser of that stage or the evaporator of the upper stage. When the compressor of the lowermost heat pump is controlled based on the temperature detected by the temperature sensor, the compressor of each upper heat pump is The first deviation rate and the second deviation rate are obtained at the set timing by the following equations at the set timing, and the control by the pressure sensor and the control by the temperature sensor are performed. of a to Ruhi Toponpu steam generator and wherein the switching control of smaller fractional deviation.
First deviation rate = (first upper limit pressure−current pressure) / (first upper limit pressure−first lower limit pressure)
Second deviation rate = (current temperature−second lower limit temperature) / (second upper limit temperature−second lower limit temperature)

The smaller the deviation rate, the closer to the target value, the smaller the operation amount of each compressor. If it is attempted to control each compressor with a larger deviation rate, that is, a larger manipulated variable, the smaller deviation rate, that is, the smaller manipulated variable, will soon reach the target value. However, according to the third aspect of the present invention, the frequency at which each compressor stops can be reduced by appropriately switching to the control with the smaller deviation rate. Moreover, even if it stops, it can transfer to a stop state gradually. Furthermore, there is no need to manually set pressure control or temperature control.

The invention according to claim 4 includes a heat pump in which a compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to circulate the refrigerant, and in the condenser, heat exchange is performed between the refrigerant and water. Steam is generated, and in the evaporator, the refrigerant and the fluid to be cooled are heat-exchanged to cool the fluid to be cooled, and the detected pressure of the pressure sensor that detects the pressure of the steam generated in the condenser is used. The compressor can be controlled based on the detected temperature of the temperature sensor provided on the outlet side of the cooled fluid flow path of the evaporator, and the compressor can be controlled based on the control by the pressure sensor. wherein controlling the compressor by switching the control by the temperature sensor, comprising a plurality of stages of the heat pump, the evaporator of the lowermost heat pump, the refrigerant and the cooling fluid to the heat exchanger, the top of the heat pump In the compressor, steam is generated, and the compressor of the uppermost heat pump is set in a range between the first upper limit pressure and the first lower limit pressure based on the detected pressure of the pressure sensor, with the first upper limit pressure as a set value. Proportional control or PID control, or based on the temperature detected by the temperature sensor, the range of the second upper limit temperature and the second lower limit temperature, and the second lower limit temperature as a set value, the lowermost heat pump compressor is proportional When controlling or PID control and controlling the compressor of the uppermost heat pump based on the pressure detected by the pressure sensor, the compressor of each lower heat pump is connected to the condenser of that stage or the evaporator of the upper stage. When the compressor of the lowermost heat pump is controlled based on the temperature detected by the temperature sensor, the compressor of each upper heat pump is The first operation amount (y1) of the compressor of the uppermost heat pump in the control by the pressure sensor at the set timing, and the temperature sensor From the second operation amount (y2) of the compressor of the lowermost heat pump in the control, a value (y1 / y2) of the ratio of the first operation amount (y1) to the second operation amount (y2) is obtained. If less than the value previously set constant, while performing the control by the pressure sensor, which is a feature and be Ruhi Toponpu steam generator to be controlled by the temperature sensor if the constant or more.

If it is attempted to control each compressor with a larger operation amount, the smaller operation amount will soon reach the target value. However, according to the fourth aspect of the present invention, the frequency at which each compressor stops can be reduced by appropriately switching to the control with the smaller operation amount. Moreover, even if it stops, it can transfer to a stop state gradually. Furthermore, there is no need to manually set pressure control or temperature control.

  ADVANTAGE OF THE INVENTION According to this invention, the heat pump type steam generator which can respond to the change of the usage load of a steam | steam can be implement | achieved. In addition, it is possible to supply steam stably to steam-using equipment while giving priority to steam generation by a heat pump by providing a fuel-fired boiler.

It is the schematic which shows one Example of the heat pump type steam generator of this invention. It is a figure which shows the modification 1 of the heat pump type steam generator of FIG. It is a figure which shows the modification 2 of the heat pump type steam generator of FIG. It is a figure which shows the modification 3 of the heat pump type steam generator of FIG. It is a figure which shows the modification 4 of the heat pump type steam generator of FIG. It is a figure which shows the modification 5 of the heat pump type steam generator of FIG. It is a figure which shows the modification 6 of the heat pump type steam generator of FIG. It is a figure which shows the modification 7 of the heat pump type steam generator of FIG. It is the schematic which shows an example of the specific structure of the condenser for vapor | steam generation in the heat pump type steam generator of FIGS. It is a figure which shows the modification of the condenser for steam generation of FIG. It is the schematic which shows the vapor | steam pressure in the heat pump type steam generator of FIGS. 1-8, and the state of a pressure-reduction valve and a compressor. It is a figure which shows the modification of FIG. It is the schematic which shows the structural example which controls a compressor based on the water temperature after passing the evaporator for warm water cooling. It is the schematic which shows the water temperature and the state of a bypass valve and a compressor in the heat pump type steam generator of FIG. It is a figure which shows the modification of FIG. It is the schematic which shows an example of the heat pump type steam generator provided with the heat pump of the multistage which can switch control by a pressure sensor and control by a temperature sensor.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing an embodiment of a heat pump type steam generator 1 of the present invention, and shows a case where a single heat pump 2 is used. FIGS. 2 to 8 are diagrams showing modifications of the heat pump steam generator 1 of the present embodiment, and FIGS. 2 to 4 are diagrams in the case of using a two-stage heat pump 2 (2A, 2B). 5 to FIG. 8 show a case where a three-stage heat pump 2 (2A, 2B, 2C) is used.

  Any heat pump steam generator 1 includes a vapor compression heat pump 2. This heat pump 2 may be a single stage or a plurality of stages regardless of the number of stages. Even when the heat pump 2 has a plurality of stages, the heat pumps 2 constituting each stage are basically the same as the single stage heat pump 2 shown in FIG. The multi-stage (multi-stage) heat pump includes a single-stage multi-stage heat pump as shown in FIG. 3, a multi-element (multi-element) heat pump as shown in FIG. 2, or a combination of both as shown in FIG. It is.

  A heat pump steam generator 1 shown in FIG. 1 includes a single-stage heat pump 2. The heat pump 2 is configured by sequentially connecting a compressor 3, a condenser 4, an expansion valve 5, and an evaporator 6 in an annular shape. The compressor 3 compresses the gas refrigerant to a high temperature and a high pressure. The condenser 4 condenses and liquefies 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.

  Therefore, in the heat pump 2, the refrigerant takes the heat from the outside and vaporizes in the evaporator 6, while in the condenser 4, the refrigerant dissipates heat to the outside and condenses. Using this, the heat pump type steam generator 1 draws heat from the warm water, air (including air having heat like air discharged from the air compressor), exhaust gas and the like in the evaporator 6 to condense. In vessel 4, water is heated to generate steam.

  The heat pump steam generator 1 shown in FIG. 2 includes two upper and lower heat pumps 2 (2A, 2B). Then, the refrigerant from the compressor 3A of the first stage (lower stage) heat pump 2A and the refrigerant from the expansion valve 5B of the second stage (upper stage) heat pump 2B are received, and heat exchange is performed without mixing both refrigerants. The indirect heat exchanger 7 is provided, and this indirect heat exchanger 7 is the condenser 4A of the first stage heat pump 2A and the evaporator 6B of the second stage heat pump 2B. In this case, in the indirect heat exchanger 7 that doubles as the condenser 4A of the first stage heat pump 2A and the evaporator 6B of the second stage heat pump 2B, the refrigerant of the first stage heat pump 2A and the second stage heat pump 2B Heat is exchanged with the refrigerant to condense the refrigerant of the first-stage heat pump 2A and vaporize the refrigerant of the second-stage heat pump 2B.

  A heat pump steam generator 1 shown in FIG. 3 includes heat pumps 2 (2A, 2B) having two upper and lower stages. The intermediate cooler 8 receives the refrigerant from the compressor 3A of the first stage heat pump 2A and the refrigerant from the expansion valve 5B of the second stage heat pump 2B, and directly contacts both refrigerants to exchange heat. The intermediate cooler 8 is the condenser 4A of the first-stage heat pump 2A and the evaporator 6B of the second-stage heat pump 2B. Specifically, a hollow tank is used as the intermediate cooler 8 and receives the refrigerant from the compressor 3A of the first-stage heat pump 2A and the refrigerant from the expansion valve 5B of the second-stage heat pump 2B. The refrigerant is condensed directly from the compressor 3A of the first stage heat pump 2A and vaporized from the expansion valve 5B of the second stage heat pump 2B. The liquid refrigerant thus obtained is sent to the expansion valve 5A of the first stage heat pump 2A, while the gas refrigerant may be sent to the compressor 3B of the second stage heat pump 2B.

  A heat pump steam generator 1 shown in FIG. 4 includes heat pumps 2 (2A, 2B) in two upper and lower stages. Then, the refrigerant from the compressor 3A of the first stage heat pump 2A and the refrigerant from the expansion valve 5B of the second stage heat pump 2B are received, and both the refrigerants are directly contacted to exchange heat. An intermediate cooler 9 is provided for heat exchange without mixing the refrigerant and the refrigerant supplied from the condenser 4B of the second stage heat pump 2B without passing through the expansion valve 5B. Specifically, an indirect heat exchanger that exchanges heat without mixing the fluids of the first region 10 and the second region 11 is used as the intercooler 9, and the first stage heat pump 2A is used in the first region 10. While the refrigerant from the compressor 3A and the refrigerant from the expansion valve 5B of the second stage heat pump 2B are directly heat-exchanged, the expansion valve is connected to the second region 11 from the condenser 4B of the second stage heat pump 2B. What is necessary is just to let a refrigerant pass through 5B. In this case, the refrigerant from the compressor 3A of the first stage heat pump 2A is subjected to intermediate cooling by the refrigerant from the expansion valve 5B of the second stage heat pump 2B in the intermediate cooler 9, and then the second stage heat pump. In the 2B compressor 3B, the high-pressure and high-temperature gas refrigerant is condensed in the condenser 4B of the second-stage heat pump 2B. A part of the liquid refrigerant is sent to the first region 10 of the intermediate cooler 9 via the expansion valve 5B of the second stage heat pump 2B, while the remaining liquid refrigerant is sent to the first cooler of the intermediate cooler 9. The pressure is reduced by the expansion valve 5B of the first stage heat pump 2A through the second region 11, vaporized in the evaporator 6A of the first stage heat pump 2A, and then returned again to the compressor 3A of the first stage heat pump 2A. .

  A heat pump steam generator 1 shown in FIG. 5 includes heat pumps 2 (2A, 2B, 2C) in three upper and lower stages. Here, the first stage heat pump 2A and the second stage heat pump 2B are connected in the same relationship as in FIG. 2, and the second stage heat pump 2B and the third stage heat pump 2C are the same as in FIG. Connected in a relationship. Specifically, indirect heat exchange that receives the refrigerant from the compressor 3A of the first-stage heat pump 2A and the refrigerant from the expansion valve 5B of the second-stage heat pump 2B and exchanges heat without mixing the two refrigerants. The indirect heat exchanger 7 is a condenser 4A of the first stage heat pump 2A and an evaporator 6B of the second stage heat pump 2B. An indirect heat exchanger 7 that receives the refrigerant from the compressor 3B of the second-stage heat pump 2B and the refrigerant from the expansion valve 5C of the third-stage heat pump 2C and exchanges heat without mixing both refrigerants. The indirect heat exchanger 7 is a condenser 4B of the second-stage heat pump 2B and an evaporator 6C of the third-stage heat pump 2C.

  The heat pump steam generator 1 shown in FIG. 6 includes upper and lower three-stage heat pumps 2 (2A, 2B, 2C). Here, the first stage heat pump 2A and the second stage heat pump 2B are connected in the same relationship as in FIG. 3, and the second stage heat pump 2B and the third stage heat pump 2C are the same as in FIG. Connected in a relationship. Specifically, an intermediate in which heat is exchanged by receiving the refrigerant from the compressor 3A of the first stage heat pump 2A and the refrigerant from the expansion valve 5B of the second stage heat pump 2B and directly contacting both refrigerants. The cooler 8 is provided, and the intermediate cooler 8 is the condenser 4A of the first-stage heat pump 2A and the evaporator 6B of the second-stage heat pump 2B. An indirect heat exchanger 7 that receives the refrigerant from the compressor 3B of the second-stage heat pump 2B and the refrigerant from the expansion valve 5C of the third-stage heat pump 2C and exchanges heat without mixing both refrigerants. The indirect heat exchanger 7 is a condenser 4B of the second-stage heat pump 2B and an evaporator 6C of the third-stage heat pump 2C.

  The heat pump type steam generator 1 shown in FIG. 7 includes upper and lower three-stage heat pumps 2 (2A, 2B, 2C). Here, the first-stage heat pump 2A and the second-stage heat pump 2B are connected in the same relationship as in FIG. 2, and the second-stage heat pump 2B and the third-stage heat pump 2C are the same as in FIG. Connected in a relationship. Specifically, indirect heat exchange that receives the refrigerant from the compressor 3A of the first-stage heat pump 2A and the refrigerant from the expansion valve 5B of the second-stage heat pump 2B and exchanges heat without mixing the two refrigerants. The indirect heat exchanger 7 is a condenser 4A of the first stage heat pump 2A and an evaporator 6B of the second stage heat pump 2B. Further, an intermediate cooler 8 that receives the refrigerant from the compressor 3B of the second stage heat pump 2B and the refrigerant from the expansion valve 5C of the third stage heat pump 2C and exchanges heat by directly contacting both refrigerants. The intermediate cooler 8 is a condenser 4B of the second stage heat pump 2B and an evaporator 6C of the third stage heat pump 2C.

  The heat pump type steam generator 1 shown in FIG. 8 includes upper and lower three-stage heat pumps 2 (2A, 2B, 2C). Here, the first stage heat pump 2A and the second stage heat pump 2B are connected in the same relationship as in FIG. 3, and the second stage heat pump 2B and the third stage heat pump 2C are the same as in FIG. Connected in a relationship. Specifically, an intermediate in which heat is exchanged by receiving the refrigerant from the compressor 3A of the first stage heat pump 2A and the refrigerant from the expansion valve 5B of the second stage heat pump 2B and directly contacting both refrigerants. The cooler 8 is provided, and the intermediate cooler 8 is the condenser 4A of the first-stage heat pump 2A and the evaporator 6B of the second-stage heat pump 2B. Further, an intermediate cooler 8 that receives the refrigerant from the compressor 3B of the second stage heat pump 2B and the refrigerant from the expansion valve 5C of the third stage heat pump 2C and exchanges heat by directly contacting both refrigerants. The intermediate cooler 8 is a condenser 4B of the second stage heat pump 2B and an evaporator 6C of the third stage heat pump 2C.

  6, the relationship between the first-stage heat pump 2A and the second-stage heat pump 2B, the relationship between the second-stage heat pump 2B and the third-stage heat pump 2C in FIG. The relationship between the heat pumps 2A, 2B, and 2C is the same as that in FIG. 3, but they may be connected in the same relationship as in FIG.

  Furthermore, although the heat pump type steam generator 1 has shown only the example using the heat pump 2 to 3 steps | paragraphs here, you may comprise with the heat pump 2 of 4 steps | paragraphs or more. At that time, the heat pumps 2 adjacent to each other may be connected in any relationship shown in FIGS.

  The refrigerant used in each heat pump 2 is not particularly limited, but hydrofluorocarbon (HFC) having 4 or more carbon atoms, or water and / or a fire extinguishing liquid added thereto, alcohol (for example, ethyl alcohol or methyl alcohol) or the like. What added water and / or a fire extinguishing liquid, or water (for example, pure water or soft water) is used suitably. By using these refrigerants, it is possible to efficiently generate heat from the exhaust hot water and generate steam. In the case of flammable HFC or alcohol, safety can be improved by mixing water and / or a fire extinguishing liquid.

  When the heat pumps 2 of a plurality of stages are used, the upper and lower heat pumps 2 and 2 are connected if the adjacent upper and lower heat pumps 2 and 2 are connected in the relationship shown in FIG. , 2 may use different refrigerants. At this time, the lower heat pump preferably uses a refrigerant having a lower boiling point than that of the upper heat pump. If the same refrigerant is used for the upper and lower heat pumps 2, 2, the lower heat pump has a lower temperature, and the specific volume of the refrigerant becomes larger. Therefore, it is necessary to increase the suction volume flow rate of the lower compressor in order to create the mass flow rate of the lower refrigerant necessary for supplying the heat necessary for the evaporation of the upper refrigerant in the heat exchanger that performs heat exchange on the upper and lower stages. There is a large compressor. However, in a multi-stage heat pump, by using a refrigerant having a lower boiling point in the lower stage than in the upper stage, the specific volume of the lower stage refrigerant can be reduced, so that an increase in size of the compressor can be prevented.

  Each heat pump 2 of a single stage or a plurality of stages uses a two-phase region of a refrigerant liquid phase and a gas phase. Therefore, the refrigerant of each heat pump 2 has a critical temperature higher than the refrigerant saturation temperature with respect to the refrigerant pressure in the condenser 4. By using the heat pump 2 utilizing the phase change from the liquid phase to the gas phase and the phase change from the gas phase to the liquid phase, latent heat can be used. When the steam is generated by heating water with the heat pump 2 as in the present invention, a large latent heat of vaporization is required, which is incomparable with the case where hot water is produced simply by heating water. Instead, it uses latent heat.

  In any case, the heat pump steam generator 1 draws up heat from hot water, air, exhaust gas, etc. in the evaporator 6Z of the lowermost heat pump (including a single heat pump) 2. For example, using warm water discharged from a factory or the like, in the evaporator 6Z of the lowermost heat pump 2, the warming of the coolant by the warm water and the cooling of the warm water by the heat of vaporization of the coolant are achieved. Then, in the condenser 4Z of the uppermost heat pump (including a single-stage heat pump) 2, water is heated to generate steam. The water supply to the steam generating condenser 4Z is pure water or soft water in order to prevent adhesion of scale (deposited hardness in water) into the heat exchanger constituting the condenser 4Z. Is preferred.

  The condenser 4 of the uppermost heat pump 2, that is, the steam generating condenser 4Z is not particularly limited as long as it is an indirect heat exchanger that exchanges heat without mixing refrigerant and water. For example, a plate heat exchanger may be used, but in this embodiment, a shell and tube heat exchanger 12 is used as shown in FIG.

  The shell-and-tube heat exchanger 12 is configured by arranging a plurality of tubes 14 in a hollow container-like shell 13, in which water is stored in one of the shell 13 and the tube 14, and a refrigerant passes through the other. Thus, water is heated and vaporized by the refrigerant in the heat exchanger 12. Which of the shell 13 and the tube 14 is used to store water and which is allowed to pass the refrigerant is appropriately set.

  When the tubes 14 are used in a vertical orientation, the air bubbles do not accumulate in the middle of the shell 13 and the tube 14, regardless of which water is stored. Further, considering that the refrigerant generally has a lower heat transfer coefficient than water and the tube 14 has a larger area on the outer peripheral surface than the inner peripheral surface, water is accumulated inside the tube 14 and the outer side (that is, the shell). It is preferable to pass a refrigerant through 13).

  When each tube 14 is used in a horizontal orientation facing left and right, as described above, considering the point that the heat transfer coefficient of the refrigerant is lower than that of water, the outside of the tube 14 where the heat transfer area becomes large (that is, the shell 13). It is better to pass the refrigerant through. In this case, even if the gas refrigerant condenses on the outer peripheral surface of the tube 14 to form droplets, there is an advantage that the droplets can be easily dropped from the tube 14. However, since bubbles may accumulate in the tube 14, it is necessary to devise such as forcibly circulating water with a pump. On the other hand, if water is accumulated in the shell 13, there is an advantage that bubbles do not accumulate in the middle.

  FIG. 9 is a schematic diagram showing an example of a specific configuration of the steam generating condenser 4Z, and shows a steam system provided with a boiler 15. Here, a shell-and-tube heat exchanger 12 is used vertically as the steam generating condenser 4Z.

  As described above, the shell-and-tube heat exchanger 12 is configured by arranging a plurality of tubes 14 in a hollow container-like shell 13. In the illustrated example, a plurality of tubes 14 are arranged in a cylindrical shell 13 in parallel with the axis of the shell 13, and both ends of each tube 14 are headers 16, which are arranged at both ends in the axial direction of the shell 13. 17 is open. Then, water is stored in one of the shell 13 and the tube 14, and the refrigerant is passed through the other, whereby the water is heated and vaporized by the refrigerant in the heat exchanger 12, while the gas refrigerant is converted by the water. Cool and condense.

  In the case of FIG. 9, the shell-and-tube heat exchanger 12 is installed vertically so that each tube 14 extends in the vertical direction. Here, water is stored in the tube 14, and the refrigerant is passed through the shell 13. Specifically, water from the water supply pump 18 can be supplied to each tube 14 via the check valve 19 via the lower header 17. By providing the check valve 19 in the water supply path 20, it is possible to prevent water from flowing backward when the water supply pump 18 is stopped.

  The feed water pump 18 is controlled based on the detection result of a water level detector (not shown), and thereby the water level in the heat exchanger 12 is maintained within a set range. Specifically, the feed water pump 18 may be operated when it falls below the lower limit water level, and the feed water pump 18 may be stopped when it exceeds the upper limit water level. However, the water supply control method is not limited to this. For example, the water supply pump 18 is inverter-controlled using a capacitance type water level detector capable of obtaining a signal proportional to the water level, and the amount of water supply is adjusted. May be. In place of inverter control of the water supply pump 18, a water supply valve (not shown) is provided between the water supply pump 18 and the check valve 19, and the opening degree of the water supply valve is adjusted while the water supply pump 18 is operated. May be.

  The gas refrigerant from the compressor 3 is supplied from above the shell 13, condensed by contacting the tube 14, and discharged as a liquid refrigerant from below the shell 13. In order to enhance the heat exchange between the refrigerant and water, it is preferable to quickly drop the refrigerant condensate from the surface of the tube 14. Therefore, it is preferable that the baffle plate 21 is disposed obliquely in the shell 13 and the tube 14 is passed through the baffle plate 21. In this case, the condensate of the refrigerant on the surface of the tube 14 is dropped below the shell 13 near the wall surface of the shell 13 along the baffle plate 21. In addition, a fin, a groove | channel, etc. may be suitably provided in the inner side and / or the outer side of the tube 14, and expansion of a heat transfer area may be aimed at.

  The water in the tube 14 is heated and vaporized by heat exchange with the refrigerant in the shell 13. The steam is sent from the upper header 16 to various steam use facilities (not shown) via the steam separator 22 as required. The steam / water separator 22 in the illustrated example has a cylindrical body 23 along the vertical direction, and is connected to the peripheral side wall of the body 23 from the upper header 16 via a steam inlet pipe 24 tangentially connected thereto. Steam is introduced into the barrel 23. The steam introduced into the cylinder 23 swirls within the cylinder 23, and the centrifugal force causes water droplets to hit the peripheral side wall of the cylinder 23 and drop downward, and the steam thus improved in dryness is transferred to the cylinder 23. It is led out from the steam outlet pipe 25 connected to the upper part.

  The steam from the steam outlet pipe 25 is sent to various types of steam using facilities through a check valve 26, a pressure reducing valve, a steam header, and the like as desired. When the steam from the steam outlet pipe 25 and the steam from the boiler (such as a fuel-fired boiler or an electric boiler) 15 are merged, when the operation of the heat pump steam generator 1 is stopped, the steam from the boiler 15 is a condenser. In order to prevent backflow to 4Z, a check valve 26 is preferably provided in the steam outlet pipe 25.

  The lower part of the trunk | drum 23 and the lower header 17 of the condenser 4Z are connected by the separated water return pipe 27, and the water centrifuged in the trunk | drum 23 is returned to the condenser 4Z. Note that, as indicated by a two-dot chain line, the upper header 16 and the lower header 17 may be connected by the downcomer 28 without the steam separator 22. A water level gauge 29 that can visually confirm the water level is provided across the trunk 23 or the separated water return pipe 27, or both the trunk 23 and the separated water return pipe 27. When the downcomer 28 is provided, a water gauge 29 may be provided in the downcomer 28. As described above, the condenser 4Z is provided with a water level detector such as an electrode type or a capacitance type.

  A drain pipe 30 is connected to the lower part of the separated water return pipe 27 so as to branch, and a drain valve 31 is provided in the drain pipe 30. As the heat pump steam generator 1 is operated, the water in the steam generating condenser 4Z is concentrated, so that the drain valve 31 is appropriately opened to drain (blow), and a part of the water in the condenser 4Z or Everything is replaced. As for the timing of this drainage, the concentration of water may be detected by an electrical conductivity sensor, but the cumulative number of rotations of the compressor 3 (preferably the compressor 3 of the uppermost heat pump 2) (heat pump steam generator 1) It is easy to use the total number of revolutions from the installation of Specifically, the next blow timing can be determined based on the accumulated rotation speed of the compressor 3 from the previous blow. This is because the degree of concentration changes depending on the amount of steam generated, and that the amount of steam is proportional to the rotational speed of the compressor 3.

  A vacuum breaker valve 32 is provided at an appropriate position from the upper header 16 of the steam generating condenser 4Z to the check valve 26. After the operation of the heat pump type steam generator 1 is stopped, if the steam in the steam generating condenser 4Z condenses, the vacuum breaker valve 32 draws outside air when the steam generating condenser 4Z tries to become negative pressure. Introduce and prevent it.

  FIG. 10 is a schematic diagram showing a modification of FIG. In FIG. 9, the steam generating condenser 4 </ b> Z is disposed such that each tube 14 extends in the vertical direction, but in FIG. 10, the steam generating condenser 4 </ b> Z is disposed obliquely. In this case, it is sufficient if the baffle plate 21 is provided in a direction orthogonal to the longitudinal direction of the tube 14. Further, FIG. 10 shows an example in which the refrigerant is introduced from the axial center portion of the shell 13. In this case, the refrigerant introduced into the shell 13 is appropriately dispersed by the baffle plate 21, passes through the shell 13, heats the water in the tube 14, and condenses itself and is discharged from the lower portion of the shell 13. The The connection of the steam inlet pipe 24 from the upper header 16 to the steam separator 22 may be connected to the center of the upper header 16 as indicated by a solid line, or left and right as indicated by a two-dot chain line. It may be a position close to the crab.

  In the heat pump steam generator 1, the compressor 3 is controlled based on the pressure of the steam generated by the steam generating condenser 4Z. Specifically, in order to detect the vapor pressure from the steam generating condenser 4Z, the upper header 16 of the steam generating condenser 4Z or the steam path 33 (the steam inlet pipe 24, the steam outlet pipe 25, etc.) ) Is provided with a pressure sensor (including a pressure switch) 34, and the compressor 3 of the heat pump 2 is controlled based on a detection signal of the pressure sensor 34.

  The compressor 3 includes a compressor main body and a driving device for the compressor, and the driving device includes an engine (typically a gas engine or a diesel engine) and / or a motor. As a specific aspect of the control of the compressor 3, for example, the drive device is on / off controlled. Alternatively, a power transmission device (clutch and / or transmission) from the drive device to the compressor main body is provided between the compressor main body and the drive device, and whether or not power is transmitted from the drive device to the compressor main body, The power transmission device is controlled to change the amount. Or the motor which comprises a drive device is controlled by an inverter, and the rotation speed (it can also be said to be a rotational speed) of a motor is changed. Alternatively, the engine output constituting the drive device is controlled to change the engine output. Alternatively, the compressor main body is controlled in order to mechanically adjust the refrigerant discharge flow rate (including the case where the discharge flow rate is changed by adjusting the suction side) of the compressor main body. Of these, a plurality of them may be combined to control the compressor 3.

  Moreover, the opening degree of the expansion valve 5 is adjusted so that the heat pump type steam generator 1 may maintain the superheat degree of the compressor 3 inlet_port | entrance (a part of FIG. 1) as desired. Specifically, the degree of superheat of the refrigerant is obtained from the pressure and temperature of the refrigerant at the compressor 3 inlet (evaporator 6 outlet), and the opening degree of the expansion valve 5 is adjusted so as to maintain this degree of superheat as desired. . In addition, when installing the liquid gas heat exchanger 35 mentioned later, the superheat degree of a refrigerant | coolant is calculated | required from the pressure and temperature of the refrigerant | coolant in the compressor 3 inlet_port | entrance (liquid gas heat exchanger 35 exit), and it maintains at a desired superheat degree. What is necessary is just to adjust the opening degree of an expansion valve so that it may do.

  When the heat pump steam generator 1 includes a plurality of heat pumps 2, the compressor 3 of the uppermost heat pump 2 is controlled based on the steam pressure from the steam generating condenser 4Z, and each lower heat pump. The two compressors 3 are preferably controlled based on the pressure or temperature of the refrigerant in the condenser 4 of the corresponding heat pump 2 (or the refrigerant in the evaporator 6 of the upper heat pump 2). Moreover, the opening degree of the expansion valve 5 of each stage is adjusted so as to maintain the superheat degree of the refrigerant at the inlet of the compressor 3 of the corresponding stage as desired.

  For example, in the heat pump steam generator 1 shown in FIG. 2, in the second stage heat pump 2B, the compressor 3B is controlled based on the pressure of the steam generated by the condenser 4B, and in the first stage heat pump 2A. Is a refrigerant in the indirect heat exchanger 7 that also serves as the condenser 4A of the first-stage heat pump 2A and the evaporator 6B of the second-stage heat pump 2B (this is a refrigerant of the first-stage heat pump 2A. The compressor 3A is controlled based on the pressure or temperature of the refrigerant of the heat pump 2B. Moreover, in the heat pump 2 of each stage, the opening degree of the expansion valve 5 is adjusted so that the degree of superheat at the inlet of the compressor 3 is maintained as desired.

  In the heat pump steam generator 1 shown in FIG. 3, in the second stage heat pump 2B, the compressor 3B is controlled based on the pressure of the steam generated in the condenser 4B, and in the first stage heat pump 2A. The compressor 3A is controlled based on the pressure in the intercooler 8. Moreover, in the heat pump 2 of each stage, the opening degree of the expansion valve 5 is adjusted so that the degree of superheat at the inlet of the compressor 3 is maintained as desired. However, for the expansion valve 5B of the second-stage heat pump 2B, the liquid in the intermediate cooler 8 (or the receiver may be used when a receiver is provided in front of the expansion valve 5B of the second-stage heat pump 2B). It is preferable to adjust the opening so that the liquid level of the refrigerant is maintained as desired.

  In the heat pump steam generator 1 shown in FIG. 4, in the second stage heat pump 2B, the compressor 3B is controlled based on the pressure of the steam generated in the condenser 4B, and in the first stage heat pump 2A. Is based on the pressure in the intercooler 9 (the pressure of the mixed refrigerant of the refrigerant from the compressor 3A of the first stage heat pump 2A and the refrigerant from the expansion valve 5B of the second stage heat pump 2B). Be controlled. Moreover, in the heat pump 2 of each stage, the opening degree of the expansion valve 5 is adjusted so that the degree of superheat at the inlet of the compressor 3 is maintained as desired.

  Similarly, when the heat pump 2 having three or more stages is provided, the compressor 3 of the uppermost heat pump 2 is controlled based on the steam pressure from the steam generating condenser 4Z, and the compressor 3 of each lower heat pump 2 is further controlled. May be controlled based on the pressure or temperature of the refrigerant in the condenser 4 of the heat pump 2 of the corresponding stage. Moreover, the expansion valve 5 of each stage may basically be adjusted in opening so as to maintain the superheat degree of the refrigerant at the inlet of the compressor 3 of the corresponding stage as desired. As described, control based on the liquid level may be performed.

  According to the heat pump steam generator 1 of the present embodiment, by controlling the compressor (directly the uppermost compressor as described above) 3 based on the steam pressure from the steam generating condenser 4Z, Steam with a desired vapor pressure can be obtained. Typically, the heat pump 2 is operated so as to maintain the vapor pressure from the vapor generating condenser 4Z at a predetermined pressure set in a desired manner, and the vapor having a predetermined pressure is stably supplied to the steam-using facility. be able to.

  For example, when the amount of steam used in the steam-using facility increases and the pressure detected by the pressure sensor 34 becomes less than a predetermined pressure, the compressor 3 is operated to generate steam, and conversely, the amount of steam used in the steam-using facility. When the detected pressure of the pressure sensor 34 becomes equal to or higher than a predetermined pressure, the compressor 3 may be stopped. In this case, needless to say, a differential (operation gap) may be provided for the pressure at which the compressor 3 is turned on and off when the vapor pressure increases and decreases. In addition to the on / off control of the compressor 3, the motor that drives the compressor 3 may be inverter controlled so that the pressure detected by the pressure sensor 34 becomes a predetermined pressure.

  As shown in FIGS. 9 and 10, the heat pump steam generator 1 may be provided with a boiler 15. This boiler 15 is typically a fuel-fired boiler or an electric boiler. The fuel-fired boiler is a device that vaporizes water by burning fuel, and the presence or amount of combustion is adjusted so as to maintain the vapor pressure in the can as desired. The electric boiler is a device that vaporizes water using an electric heater, and the presence or amount and the amount of electric power supplied to the electric heater are adjusted so that the vapor pressure in the can is maintained as desired. However, the boiler 15 is not limited to a fuel-fired boiler or an electric boiler, and may be a waste heat boiler or the like. In the case of a waste heat boiler, the heat source is not particularly limited, and for example, exhaust gas from an engine or the like, or waste heat from a SOFC (solid oxide fuel cell) can be used.

  A steam path 36 from the boiler 15 is connected to the steam path 33 from the steam generating condenser 4Z to the steam using facility. This connection can also be made at the steam header. A pressure reducing valve 37 is provided in the steam path 36 from the boiler 15. The set pressure of the pressure reducing valve 37 is preferably set lower than the predetermined pressure for controlling the compressor.

  A pressure sensor 34 is provided at a position where the pressure of the combined steam of the steam from the heat pump 2 (specifically, the condenser 4) and the steam from the boiler 15 can be detected. In the illustrated example, the pressure sensor 34 is provided in the steam path after the steam from the condenser 4 and the boiler 15 is joined. However, the steam from the heat pump 2 and the steam from the boiler 15 are joined at the steam header. In the case of making it, the pressure sensor 34 may be provided in the steam header. Further, if the pressure of the combined steam can be detected, the steam path from the condenser 4 may be upstream from the junction, or the steam path from the boiler 15 and upstream from the junction. It may be provided downstream of the pressure reducing valve 37. However, when the check valve 26 is provided, it is provided on the downstream side of the check valve 26.

  FIG. 11 is a schematic diagram showing the detected pressure of the pressure sensor 34, the open / close state of the pressure reducing valve 37, and the operating state of the uppermost compressor 3. Here, an example will be described in which the compressor 3 is turned on / off at the first set pressure (= “predetermined pressure”) P1 and the pressure reducing valve 37 is opened / closed at the second set pressure P2.

  When the detected pressure of the pressure sensor 34 is less than the second set pressure P2, the compressor 3 is driven and the pressure reducing valve 37 is open. Thereby, the steam from the heat pump 2 and the boiler 15 is supplied to the steam using facility. And if it becomes more than 2nd setting pressure P2, the pressure-reduction valve 37 will close, the vapor | steam supply from the boiler 15 will be stopped, and a vapor | steam will be supplied from the heat pump 2. FIG. When the detected pressure of the pressure sensor 34 is equal to or higher than the first set pressure P1, the compressor 3 is stopped and the supply of steam from the heat pump 2 is also stopped. Then, when the pressure detected by the pressure sensor 34 is less than the first set pressure P1, the compressor 3 is driven and cannot be covered by only the steam generated by the heat pump 2, and when the pressure is less than the second set pressure P2, the pressure reducing valve 37 is opened. Steam is also supplied from the boiler 15.

  Needless to say, a differential (operation gap) is set for each of the first set pressure P1 and the second set pressure P2. The compressor 3 may be controlled not only by on / off control but also by proportional control or PID control, or by installing an electric valve (such as a motor valve or a proportional control valve) in place of the pressure reducing valve 37, The motor-operated valve may be controlled so as to maintain the detected pressure at the second set pressure P2.

  These cases will be described with reference to FIG. In FIG. 12, the differential (or proportional band) P1H to P1L of the first set pressure P1 and the differential (or proportional band) P2H to P2L of the second set pressure P2 do not overlap. You may overlap. That is, the second upper limit pressure P2H may be set higher than the first lower limit pressure P1L.

  First, on / off control in which differentials are respectively set for the first set pressure P1 and the second set pressure P2 will be described. In this case, the first upper limit pressure P1H and the first lower limit pressure P1L are set for the first set pressure P1, and when the pressure detected by the pressure sensor 34 becomes equal to or higher than the first upper limit pressure P1H when the pressure rises, the compressor 3 When the pressure stops, and when the pressure detected by the pressure sensor 34 becomes less than the first lower limit pressure P1L, the compressor 3 is driven. For the second set pressure P2, a second upper limit pressure P2H and a second lower limit pressure P2L are set, and when the pressure rises, when the pressure exceeds the second upper limit pressure P2H, the pressure reducing valve 37 (self-powered pressure reducing valve or solenoid valve). Is closed, and when the pressure drops, the pressure reducing valve 37 opens when the pressure falls below the second lower limit pressure P2L.

  Next, an example in the case of proportionally controlling the compressor 3 and the electric valve (electric valve installed in place of the pressure reducing valve 37) will be described. In this case, based on the pressure detected by the pressure sensor 34, the compressor 3 is proportionally controlled in a range between the first upper limit pressure P1H and the first lower limit pressure P1L and with the first upper limit pressure P1H as a set value (target value). . Typically, the rotation speed of the compressor 3 is changed. Further, based on the pressure detected by the pressure sensor 34, the motor-operated valve is proportionally controlled in the range between the second upper limit pressure P2H and the second lower limit pressure P2L and using the second upper limit pressure P2H as a set value (target value). That is, the opening degree of the electric valve is adjusted. Here, at the first upper limit pressure P1H or more, the compressor 3 stops, and at less than the first lower limit pressure P1L, the compressor 3 operates at full load. In addition, when the pressure is equal to or higher than the second upper limit pressure P2H, the motor-operated valve is fully closed. Note that PID control may be performed instead of proportional control.

  In either case, the water temperature on the outlet side of the evaporator 6 is monitored by a temperature sensor 39 to be described later, and if this temperature falls below the lower limit value, a desired steam cannot be obtained even if the heat pump 2 is operated. 3 may be stopped.

  In any case, by setting the second set pressure P2 lower than the first set pressure P1, it is possible to stably supply steam to the steam using equipment while giving priority to the operation of the heat pump 2. At this time, in particular, by using the pressure reducing valve 37, the presence or absence of steam supply from the boiler 15 is switched on its own, giving priority to the operation of the heat pump 2, and if this is not sufficient, the steam from the boiler 15 is used as steam using equipment. Can be sent to.

  By the way, the heat pump type steam generator 1 of the present embodiment controls the compressor 3 based on the steam pressure from the steam generating condenser 4Z, and in addition to the hot water cooling evaporator (the bottom heat pump evaporator) 6Z. The compressor 3 may be controlled based on the water temperature after being passed (FIG. 1). Specifically, in order to detect the water temperature after cooling by the warm water cooling evaporator 6Z, a temperature sensor 39 is provided in the warm water cooling evaporator 6Z or the drainage passage 38 therefrom. The compressor 3 of the heat pump 2 is controlled based on the detection signal. In such a configuration, warm water can be reliably cooled to a desired temperature in the warm water cooling evaporator 6Z.

  When the compressor 3 is controlled based on the water temperature after passing through the warm water cooling evaporator 6Z in the steam generator 1 including the plurality of stages of heat pumps 2, the compressor 3 of the lowermost stage heat pump 2 is: It is controlled based on the water temperature after passing through the warm water cooling evaporator 6Z, and the compressor 3 of each upper heat pump 2 is connected to the evaporator 6 of the corresponding heat pump 2 (or one lower heat pump 2). Control may be based on the pressure or temperature of the refrigerant in the condenser 4).

  When the compressor 3 is controlled based on the water temperature after passing through the warm water cooling evaporator 6Z, the amount of steam generated in the steam generating condenser 4Z cannot be directly controlled, but as described above, the heat pump steam By providing the boiler 15 in the generator 1, steam can be stably supplied to the steam using facility.

  FIG. 13 is a diagram showing a configuration example of a steam system in the case where the compressor 3 is controlled based on the water temperature after passing through the warm water cooling evaporator 6Z. Here, the configuration is shown in a simplified manner, but it goes without saying that the heat pump 2 can be provided in a plurality of stages, and a liquid-gas heat exchanger 35, a subcooler 40, and the like described later may be provided.

  In the case of FIG. 13, a water supply path 41 to the evaporator 6 and a drain path 38 from the evaporator 6 are connected by a bypass path 42, and a temperature sensor is connected to the drain path 38 upstream from the junction with the bypass path 42. 39 is provided. The temperature sensor 39 monitors the water temperature on the outlet side of the evaporator 6.

  Moreover, it is comprised so that adjustment of the bypass flow volume which flows into the drainage channel 38 via the bypass channel 42 without passing through the evaporator 6 is possible. Specifically, in the illustrated example, a bypass valve 43 formed of a three-way valve is provided at a branch portion between the water supply channel 41 and the bypass channel 42. However, instead of installing a three-way valve at the branch portion, a valve may be provided in the water supply passage 41 and / or the bypass passage 42 downstream from the branch portion so that the bypass flow rate can be adjusted. In any case, the flow rate through the evaporator 6 is adjusted by adjusting the bypass flow rate.

  In the case of FIG. 13, the bypass flow rate (also referred to as the amount of water supplied to the evaporator 6 as described above) is controlled to maintain the temperature detected by the temperature sensor 39 at the first set temperature T1. The compressor 3 is controlled to maintain the temperature detected by the temperature sensor 39 at the second set temperature T2. Then, the second set temperature T2 is set lower than the first set temperature T1 (FIG. 14).

  FIG. 14 is a schematic diagram illustrating the temperature detected by the temperature sensor 39, the open / close state of the bypass valve 43, and the operating state of the compressor 3. Here, an example in which the bypass valve 43 is opened / closed at the first set temperature T1 and the compressor 3 is turned on / off at the second set temperature T2 will be described. When the bypass valve 43 is on / off controlled, when the bypass valve 43 is closed, water supply to the bypass passage 42 is completely stopped, whereas when the bypass valve 43 is opened, water supply to the bypass passage 42 is stopped. Be started. At this time, water may be supplied to the evaporator 6 and the bypass passage 42 at a predetermined rate, or water supply to the evaporator 6 may be stopped.

  If the temperature detected by the temperature sensor 39 is lower than the second set temperature T2, the compressor 3 is stopped and the bypass valve 43 is closed because the desired steam cannot be obtained even when the heat pump 2 is operated. In this state, the steam from the boiler 15 is supplied to the steam using facility. And if it becomes 2nd preset temperature T2 or more, the compressor 3 will act | operate and a vapor | steam will be supplied from the heat pump 2. FIG. When the temperature detected by the temperature sensor 39 is equal to or higher than the first set temperature T1, the bypass valve 43 is opened and the heat pump 2 is protected. It should be noted that when the temperature detected by the temperature sensor 39 further rises and exceeds the upper limit value TH, the compressor 3 should be forcibly stopped.

  Needless to say, a differential (operation gap) is set for each of the first set temperature T1 and the second set temperature T2. The compressor 3 and the bypass valve 43 may be proportionally controlled as well as on / off control.

  These cases will be described with reference to FIG. In FIG. 15, the differential (or proportional band) T1H to T1L of the first set temperature T1 and the differential (or proportional band) T2H to T2L of the second set temperature T2 do not overlap, but some You may overlap. That is, the second upper limit temperature T2H may be set higher than the first lower limit temperature T1L.

  First, on / off control in which differentials are respectively set for the first set temperature T1 and the second set temperature T2 will be described. In this case, a first upper limit temperature T1H and a first lower limit temperature T1L are set for the first set temperature T1, and when the temperature detected by the temperature sensor 39 becomes equal to or higher than the first upper limit temperature T1H, When the temperature is lowered and the temperature sensor 39 detects a temperature lower than the first lower limit temperature T1L, the bypass valve 43 is closed. For the second set temperature T2, the second upper limit temperature T2H and the second lower limit temperature T2L are set. When the temperature rises, the compressor 3 operates when the temperature exceeds the second upper limit temperature T2H. When the temperature becomes lower than the second lower limit temperature T2L, the compressor 3 stops.

  Next, an example in the case of proportionally controlling the compressor 3 and the bypass valve 43 will be described. In this case, on the basis of the temperature detected by the temperature sensor 39, the bypass valve 43 is proportionally controlled in the range between the first upper limit temperature T1H and the first lower limit temperature T1L and using the first lower limit temperature T1L as a set value (target value). . Further, based on the temperature detected by the temperature sensor 39, the compressor 3 is proportionally controlled in a range between the second upper limit temperature T2H and the second lower limit temperature T2L and using the second lower limit temperature T2L as a set value (target value). Here, the bypass valve 43 is fully closed below the first lower limit temperature T1L, and the bypass valve 43 is fully opened above the first upper limit temperature T1H. Moreover, if it is less than 2nd minimum temperature T2L, the compressor 3 will stop, and if it is 2nd upper limit temperature T2H or more, the compressor 3 carries out full load operation. Note that PID control may be performed instead of proportional control.

  In any case, the vapor pressure is monitored by the pressure sensor 34 described above, and if this pressure exceeds the upper limit value, it is not necessary to operate the heat pump 2 to generate steam, so the compressor 3 should be stopped. . The bypass valve 43 may be a self-regulating temperature control valve that is opened and closed in the same manner as this control, in addition to being controlled based on the temperature detected by the temperature sensor 39.

  As described above, the compressor 3 is controlled based on the detected pressure of the pressure sensor 34 (FIGS. 11 and 12), or alternatively, controlled based on the detected temperature of the temperature sensor 39 (FIG. 14). , FIG. 15). However, the compressor 3 may be controlled based on both the pressure sensor 34 and the temperature sensor 39. One example will be described next. This can be said to be a combination of the control according to FIG. 12 and the control according to FIG.

  First, the compressor 3 can be proportionally controlled based on the pressure detected by the pressure sensor 34 in a range between the first upper limit pressure P1H and the first lower limit pressure P1L and using the first upper limit pressure P1H as a set value. Further, the compressor 3 can be proportionally controlled based on the temperature detected by the temperature sensor 39 in the range between the second upper limit temperature T2H and the second lower limit temperature T2L and using the second lower limit temperature T2L as a set value. Then, at the set timing (for example, every set time), the first deviation rate η1 and the second deviation rate η2 are obtained by the following formulas, and the control with the pressure sensor 34 and the control with the temperature sensor 39 has the smaller deviation rate. The compressor 3 may be controlled by switching to this control. Specifically, when the relationship of η1 <η2 is satisfied, the compressor 3 may be proportionally controlled based on the pressure detected by the pressure sensor 34. When the relationship of η1> η2 is satisfied, the compression is performed based on the temperature detected by the temperature sensor 39. The machine 3 may be proportionally controlled. The current pressure P is a pressure detected by the pressure sensor 34, and the current temperature T is a temperature detected by the temperature sensor 39.

First deviation rate η1 = (first upper limit pressure P1H−current pressure P) / (first upper limit pressure P1H−first lower limit pressure P1L)
Second deviation rate η2 = (current temperature T−second lower limit temperature T2L) / (second upper limit temperature T2H−second lower limit temperature T2L)

  The smaller the deviation rate is, the closer to the target value, the smaller the operation amount of the compressor 3. If an attempt is made to control the compressor 3 with a larger deviation rate, that is, a larger manipulated variable, the smaller deviation rate, that is, the smaller manipulated variable, will soon reach the target value. However, the frequency at which the compressor 3 stops can be reduced by appropriately switching to the control with the smaller deviation rate. Moreover, even if it stops, it can transfer to a stop state gradually. Furthermore, there is no need to manually set pressure control or temperature control.

  During this control, if the temperature detected by the temperature sensor 39 becomes lower than the lower limit, the temperature detected by the temperature sensor 39 becomes higher than the upper limit, or the pressure detected by the pressure sensor 34 becomes higher than the upper limit, the compressor 3 Should be forcibly stopped. Note that PID control may be performed instead of proportional control.

  The control by the pressure sensor 34 and the control by the temperature sensor 39 may be switched based on the operation amount of the compressor 3 in addition to switching based on the deviation rate as described above. Also in this case, the compressor 3 is based on the pressure detected by the pressure sensor 34 and is in a range between the first upper limit pressure P1H and the first lower limit pressure P1L, and the proportional control or PID control using the first upper limit pressure P1H as a set value. It is possible. Further, the compressor 3 can perform proportional control or PID control within the range between the second upper limit temperature T2H and the second lower limit temperature T2L and the second lower limit temperature T2L as a set value based on the temperature detected by the temperature sensor 39. Is done. Then, at the set timing (for example, every set time), the operation amount of the compressor 3 in the control by the pressure sensor 34 and the operation amount of the compressor 3 in the control by the temperature sensor 39 are obtained, and the control by the pressure sensor 34 and the temperature sensor Of the control by 39, the compressor 3 may be controlled by the smaller operation amount. For example, when the control by the pressure sensor 34 requires the operation amount X, while the control by the temperature sensor 39 requires the operation amount Y, if the relationship X <Y holds, the detected pressure of the pressure sensor 34 And the compressor 3 may be controlled based on the temperature detected by the temperature sensor 39 if X> Y.

  When the control by the pressure sensor 34 and the control by the temperature sensor 39 are switched based on the deviation rate or the operation amount, the heat pump 2 may have a plurality of stages as shown in FIG. In FIG. 16, two stages of heat pumps 2A and 2B are shown, but three or more stages can be similarly controlled. Moreover, in FIG. 16, although the liquid gas heat exchanger 35, the subcooler 40, etc. are not provided, it cannot be overemphasized that these may be provided.

  In this case, the compressor 3B of the uppermost heat pump 2B is within a range between the first upper limit pressure P1H and the first lower limit pressure P1L based on the detected pressure of the pressure sensor 34, and uses the first upper limit pressure P1H as a set value. Proportional control or PID control is possible. Further, the compressor 3A of the lowermost heat pump 2A is in a range between the second upper limit temperature T2H and the second lower limit temperature T2L based on the temperature detected by the temperature sensor 39 and is proportional to the second lower limit temperature T2L as a set value. Control or PID control is possible.

  Then, as shown by the broken line, when the compressor 3B of the uppermost heat pump 2B is controlled based on the detected pressure of the pressure sensor 34, the compressor 3A of each lower heat pump 2A is connected to the condenser 4A or It is controlled based on the pressure of the refrigerant in the upper evaporator 6B (detected pressure of the refrigerant pressure sensor 44). Further, as indicated by the one-dot chain line, when the compressor 3A of the lowermost heat pump 2A is controlled based on the temperature detected by the temperature sensor 39, the compressor 3B of each upper heat pump 2B is connected to the evaporator 6B of that stage. Alternatively, the control is performed based on the refrigerant pressure (detected pressure of the refrigerant pressure sensor 44) of the one lower condenser 4A. The refrigerant pressure in the condenser 4 may be detected at any location from the compressor 3 outlet to the expansion valve 5 inlet. The refrigerant pressure in the evaporator 6 is detected from the expansion valve 5 outlet to the compressor 3 inlet. It may be detected at any point up to.

  When the switching control is performed based on the deviation rate, the first deviation rate η1 and the second deviation rate η2 are obtained at the set timing in the same manner as described above, and the control by the pressure sensor 34 and the control by the temperature sensor 39 are included. It is only necessary to switch to the control with the smaller deviation rate.

  Alternatively, when switching control is performed based on the operation amount, the operation amount (first operation amount y1) of the uppermost compressor 3B in the control by the pressure sensor 34 and the lowermost compressor in the control by the temperature sensor 39 at the set timing. A value y1 / y2 of the ratio of the first operation amount y1 to the second operation amount y2 is obtained from the operation amount of 3A (second operation amount y2). If this value is less than a preset constant, the pressure sensor 34 On the other hand, if it is above the constant, the temperature sensor 39 may be used.

  By the way, in the single stage heat pump 2 or a part or all of the heat pumps 2 of the plurality of stages, a liquid gas heat exchanger 35 is installed as shown by a two-dot chain line in FIGS. Also good. In the liquid gas heat exchanger 35, heat exchange is performed without mixing the refrigerant from the condenser 4 to the expansion valve 5 and the refrigerant from the evaporator 6 to the compressor 3. Thereby, the refrigerant from the evaporator 6 to the compressor 3 is superheated by the liquid gas heat exchanger 35 with the refrigerant from the condenser 4 to the expansion valve 5. Thereby, the coefficient of performance (COP) of the heat pump 2 can be increased by increasing the enthalpy on the inlet side of the compressor 3 and thereby increasing the enthalpy on the outlet side of the compressor 3. In addition, the disadvantage that the liquid refrigerant is supplied to the compressor 3 can be prevented.

  However, in the case of a multi-stage heat pump 2, it is preferable not to provide the liquid gas heat exchanger 35 in the uppermost heat pump 2. By not providing the liquid gas heat exchanger 35 in the uppermost heat pump 2 that is at high temperature and high pressure, temperature rise on the outlet side of the compressor can be prevented, and deterioration of the lubricating oil in the compressor 3 can be prevented. Can do.

  Moreover, you may provide the subcooler 40 which cools the refrigerant | coolant from the steam generator condenser 4Z to the expansion valve 5 with the water supply to the steam generator condenser 4Z. In this case, the subcooler 40 can supercool the refrigerant from the condenser 4 to the expansion valve 5 and can also heat the water supplied to the condenser 4. Further, the heat exchange between the refrigerant and water is divided into the subcooler 40 as a heat exchange part by sensible heat and the condenser 4 as a heat exchange part mainly by latent heat, so heat transfer efficiency is good. When both the liquid gas heat exchanger 35 and the subcooler 40 are provided, the refrigerant on the outlet side of the subcooler 40 is passed through the liquid gas heat exchanger 35 in the two-dot chain line in the illustrated example. (Although not shown in the figures after 2), the refrigerant may be passed through the liquid gas heat exchanger 35 from between the condenser 4 and the subcooler 40 as indicated by a one-dot chain line. At this time, the refrigerant may be passed through the liquid gas heat exchanger 35 from between the condenser 4 and the subcooler 40 and then returned to the outlet side of the subcooler 40 instead of returning to the inlet side of the subcooler 40. That is, the refrigerant from the condenser 4 is supplied in parallel to the liquid gas heat exchanger 35 and the subcooler 40, and the refrigerants from the liquid gas heat exchanger 35 and the subcooler 40 are merged and sent to the expansion valve 5. You may comprise.

  In addition, since the steam generating condenser 4Z still radiates heat even if it is surrounded by a heat insulating material, water heated by using this heat radiating may be vaporized in the steam generating condenser 4Z.

  Moreover, since there is also heat radiation from the compressor 3, water heated by using this heat radiation may be supplied to the steam generating condenser 4Z and vaporized. In order to cool the compressor 3 with water supplied to the steam generating condenser 4Z, water may be passed through a water cooling wall provided in the casing of the compressor body.

  Furthermore, the water heated by the heat of the steam generating condenser 4Z and / or the compressor 3 may be supplied to the evaporator 6Z of the heat pump 2 at the single stage or the lowermost stage.

  When the heat pump steam generator 1 includes a plurality of stages of heat pumps 2, the heat pump steam generator 1 includes a plurality of compressors 3. In addition, as a case where a plurality of compressors 3 are provided, a plurality of compressors 3 may be installed in parallel between the evaporator 6 and the condenser 4 of each heat pump 2 of a single stage or a plurality of stages. In addition, a plurality of heat pump steam generators 1 may be installed in parallel. In any case, the plurality of compressors 3 may be configured by a compressor main body and a driving device thereof, respectively, and the plurality of compressor main bodies may be driven by a common driving device by a belt transmission device or the like.

  The plurality of compressors 3 can be controlled by a common controller and / or individual controllers. At this time, when a plurality of compressors 3 are installed in parallel between the evaporator 6 and the condenser 4 of the heat pump 2, or a plurality of heat pump steam generators 1 are installed in parallel to join the steam. In this case, even if the operating number of the plurality of compressors 3 is changed based on the steam pressure generated by the steam generating condenser 4Z and / or the water temperature after passing through the warm water cooling evaporator 6Z. Good.

  For example, in the case of controlling the number of two compressors 3, referring to FIG. 11, both units are operated when the pressure is less than the second set pressure P 2, and only one unit is operated when the pressure is greater than or equal to the second set pressure P 2 and less than the first set pressure P 1. It is only necessary to operate and stop both units at the first set pressure P1 or higher. At this time, when any one unit is stopped, the compressor 3 having a long operation time is stopped, and when any one unit is driven, the compressor 3 having a short operation time is driven. In addition, you may use the integral rotation speed of each compressor 3 as an operating time.

  Further, based on the steam pressure generated by the steam generating condenser 4Z or the water temperature after passing through the warm water cooling evaporator 6Z, the refrigerant is used for at least one compressor 3 among the plurality of compressors 3. The discharge flow rate may be adjusted. If the refrigerant discharge flow rate is adjusted with at least one compressor 3, for example, the number of operating units can be changed smoothly. The adjustment of the refrigerant discharge flow rate can be realized, for example, by inverter control of a motor that drives the compressor body.

  Further, when both the engine and the motor are provided as the drive device for the compressor 3, which of the engine and the motor is used to operate the compressor 3 or both are used to operate the compressor 3? May be changed based on the steam pressure generated by the steam generating condenser 4Z or the water temperature after passing through the warm water cooling evaporator 6Z. In addition, when an engine and a motor are provided and the compressor 3 is controlled by a clutch, the engine remains driven even when the clutch is disengaged, so that the engine is suitable for power generation by the generator during that time.

  Further, the vapor pressure generated by the steam generating condenser 4Z is maintained within the set range as described above, but if the set pressure exceeds the range by any chance, the compression of each heat pump 2 is performed. If it is configured to forcibly stop the machine 3, safety can be improved. Note that the vapor pressure on the refrigerant side may be monitored instead of the vapor pressure on the water side. In addition, the temperature of the fluid to be cooled (exhaust hot water or the like) at the inlet or outlet of the evaporator 6, or the pressure or temperature of the refrigerant in the heat pump cycle (for example, the inlet of the compressor 3, the expansion valve 5 or the intercoolers 8, 9) Alternatively, the pressure or temperature of the refrigerant at the outlet may be monitored, and if it exceeds the upper limit value, the operation of the heat pump 2 may be interlocked.

  The heat pump steam generator 1 of the present invention is not limited to the configuration of each of the embodiments described above, and can be changed as appropriate. In particular, each heat pump 2 of a single stage or a plurality of stages is not limited to the configuration described based on FIGS. 1 to 8 and can be appropriately changed. For example, the evaporator 6 may be installed in parallel, or a set of the expansion valve 5 and the evaporator 6 may be installed in parallel. Further, an oil separator may be installed on the outlet side of the compressor 3, or a liquid receiver may be installed on the outlet side of the condenser 4. Furthermore, an accumulator may be installed on the inlet side of the compressor 3.

  Moreover, although the said Example demonstrated the example which pumps up heat from warm water and generate | occur | produces a vapor | steam, it may replace with warm water and air, waste gas, etc. may be used.

  Furthermore, it is used as waste water discharged from factories, water used as cooling water for the compressor 3, water used as cooling water in the oil cooler of the engine (drive device of the compressor 3), and cooling water for the engine jacket. The water used for cooling the exhaust gas from the boiler 15 or one or more of the water used as the cooling water for the exhaust gas from the boiler 15 is used to heat the water supplied to the condenser 4, the water supplied to the evaporator 6, or the boiler 15. The water itself used as each cooling water may be used for water supply to the condenser 4 and the boiler 15 or may be passed through the evaporator 6. For example, an indirect heat exchanger is installed in the water supply path 20 to the condenser 4 (upstream side of the water supply path 20 when the subcooler 40 is provided), and passes the waste water from the factory or the oil cooler. The water supplied to the condenser 4 can be heated with the water afterwards.

  In FIG. 13, a water supply path 41 to the evaporator 6 and a drainage path 38 from the evaporator 6 are connected by a bypass path 42, and a bypass valve 43 provided at a branch portion between the water supply path 41 and the bypass path 42 is used. Although the water supply amount passing through the evaporator 6 is adjusted, the amount of water passing through the evaporator 6 can be appropriately changed as long as the amount of water passing through the evaporator 6 can be adjusted. For example, a three-way valve is provided in the water supply path 41 to the evaporator 6 to branch a part of the water supply as in FIG. 13. Or returned to the cooling tower or drained as it is. Alternatively, in FIG. 13, instead of omitting the installation of the bypass passage 42 and the bypass valve 43, a valve may be provided in the water supply passage 41 and the opening / closing or opening degree of the valve may be adjusted. In any case, the drainage from the drainage channel 38 may be discarded as it is, returned to a cooling tower or the like, or may be returned to the facility if it is cooled by the evaporator 6.

DESCRIPTION OF SYMBOLS 1 Heat pump type steam generator 2 (2A-2C) Heat pump 3 (3A-3C) Compressor 4 (4A-4C) Condenser 4Z Condenser for steam generation (condenser of uppermost heat pump)
5 (5A-5C) Expansion valve 6 (6A-6C) Evaporator 6Z Evaporator for hot water cooling (evaporator of the lowest heat pump)
7 Indirect heat exchanger 8 (Tank type) Intermediate cooler 9 (Heat exchange type) Intermediate cooler 15 Boiler 33 Steam path (from steam generating condenser) 34 Pressure sensor 35 Liquid gas heat exchanger 36 (From boiler ) Steam path 37 Pressure reducing valve 38 Drainage path 39 Temperature sensor 40 Subcooler 41 Water supply path 42 Bypass path 43 Bypass valve

Claims (4)

A compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to include a heat pump that circulates refrigerant,
In the condenser, heat is exchanged between the refrigerant and water to generate steam,
In the evaporator, heat exchange is performed between the refrigerant and the fluid to be cooled to cool the fluid to be cooled.
The compressor can be controlled based on the detected pressure of the pressure sensor that detects the pressure of the steam generated in the condenser, and a temperature sensor provided on the outlet side of the cooled fluid flow path of the evaporator. Based on the detected temperature, the compressor can be controlled,
Switching the control by the pressure sensor and the control by the temperature sensor to control the compressor ,
Based on the detected pressure of the pressure sensor, the compressor is proportionally controlled or PID controlled in a range between a first upper limit pressure and a first lower limit pressure, and the first upper limit pressure as a set value,
Based on the detected temperature of the temperature sensor, the compressor is proportionally controlled or PID controlled in a range between a second upper limit temperature and a second lower limit temperature, and the second lower limit temperature as a set value,
The first deviation rate and the second deviation rate are obtained by the following formula at the set timing, and the compressor is controlled by the smaller deviation rate of the control by the pressure sensor and the control by the temperature sensor. to Ruhi Toponpu steam generator.
First deviation rate = (first upper limit pressure−current pressure) / (first upper limit pressure−first lower limit pressure)
Second deviation rate = (current temperature−second lower limit temperature) / (second upper limit temperature−second lower limit temperature) A compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to include a heat pump that circulates refrigerant,
In the condenser, heat is exchanged between the refrigerant and water to generate steam,
In the evaporator, heat exchange is performed between the refrigerant and the fluid to be cooled to cool the fluid to be cooled.
The compressor can be controlled based on the detected pressure of the pressure sensor that detects the pressure of the steam generated in the condenser, and a temperature sensor provided on the outlet side of the cooled fluid flow path of the evaporator. Based on the detected temperature, the compressor can be controlled,
Switching the control by the pressure sensor and the control by the temperature sensor to control the compressor ,
Based on the detected pressure of the pressure sensor, the compressor is proportionally controlled or PID controlled in a range between a first upper limit pressure and a first lower limit pressure, and the first upper limit pressure as a set value,
Based on the detected temperature of the temperature sensor, the compressor is proportionally controlled or PID controlled in a range between a second upper limit temperature and a second lower limit temperature, and the second lower limit temperature as a set value,
The operation amount of the compressor in the control by the pressure sensor and the operation amount of the compressor in the control by the temperature sensor are obtained at the set timing, and the operation of the control by the pressure sensor and the control by the temperature sensor is determined. the amount to control the compressor in smaller features and be Ruhi Toponpu steam generating device. A compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to include a heat pump that circulates refrigerant,
In the condenser, heat is exchanged between the refrigerant and water to generate steam,
In the evaporator, heat exchange is performed between the refrigerant and the fluid to be cooled to cool the fluid to be cooled.
The compressor can be controlled based on the detected pressure of the pressure sensor that detects the pressure of the steam generated in the condenser, and a temperature sensor provided on the outlet side of the cooled fluid flow path of the evaporator. Based on the detected temperature, the compressor can be controlled,
Switching the control by the pressure sensor and the control by the temperature sensor to control the compressor ,
It has a multi-stage heat pump,
In the evaporator of the lowermost heat pump, heat exchange is performed between the refrigerant and the fluid to be cooled,
In the condenser of the top heat pump, steam is generated,
On the basis of the detected pressure of the pressure sensor, the range of the first upper limit pressure and the first lower limit pressure, and using the first upper limit pressure as a set value, proportional control or PID control of the compressor of the uppermost heat pump,
Based on the detected temperature of the temperature sensor, in the range between the second upper limit temperature and the second lower limit temperature, and the second lower limit temperature as a set value, proportional control or PID control of the compressor of the lowermost heat pump,
When controlling the compressor of the uppermost heat pump based on the detected pressure of the pressure sensor, the compressor of each lower heat pump is controlled based on the pressure of the refrigerant of the condenser of that stage or the evaporator of the upper stage. And
When controlling the compressor of the lowermost heat pump based on the temperature detected by the temperature sensor, the compressor of each upper heat pump is controlled based on the refrigerant pressure of the evaporator of the lower stage or the condenser of the lower stage. And
Obtains a first deviation rate by the following equation and the second deviation rate setting timing, the out of control due to the pressure said temperature sensor and the control by the sensor, to a feature to switch the control of smaller fractional deviation Ruhi A steam pump type steam generator.
First deviation rate = (first upper limit pressure−current pressure) / (first upper limit pressure−first lower limit pressure)
Second deviation rate = (current temperature−second lower limit temperature) / (second upper limit temperature−second lower limit temperature) A compressor, a condenser, an expansion valve, and an evaporator are sequentially connected in an annular manner to include a heat pump that circulates refrigerant,
In the condenser, heat is exchanged between the refrigerant and water to generate steam,
In the evaporator, heat exchange is performed between the refrigerant and the fluid to be cooled to cool the fluid to be cooled.
The compressor can be controlled based on the detected pressure of the pressure sensor that detects the pressure of the steam generated in the condenser, and a temperature sensor provided on the outlet side of the cooled fluid flow path of the evaporator. Based on the detected temperature, the compressor can be controlled,
Switching the control by the pressure sensor and the control by the temperature sensor to control the compressor ,
It has a multi-stage heat pump,
In the evaporator of the lowermost heat pump, heat exchange is performed between the refrigerant and the fluid to be cooled,
In the condenser of the top heat pump, steam is generated,
On the basis of the detected pressure of the pressure sensor, the range of the first upper limit pressure and the first lower limit pressure, and using the first upper limit pressure as a set value, proportional control or PID control of the compressor of the uppermost heat pump,
Based on the detected temperature of the temperature sensor, in the range between the second upper limit temperature and the second lower limit temperature, and the second lower limit temperature as a set value, proportional control or PID control of the compressor of the lowermost heat pump,
When controlling the compressor of the uppermost heat pump based on the detected pressure of the pressure sensor, the compressor of each lower heat pump is controlled based on the pressure of the refrigerant of the condenser of that stage or the evaporator of the upper stage. And
When controlling the compressor of the lowermost heat pump based on the temperature detected by the temperature sensor, the compressor of each upper heat pump is controlled based on the refrigerant pressure of the evaporator of the lower stage or the condenser of the lower stage. And
At the set timing, from the first operation amount (y1) of the compressor of the uppermost heat pump in the control by the pressure sensor and the second operation amount (y2) of the compressor of the lowermost heat pump in the control by the temperature sensor Then, a value (y1 / y2) of the ratio of the first operation amount (y1) to the second operation amount (y2) is obtained, and if this value is less than a preset constant, control by the pressure sensor is performed, features and to Ruhi Toponpu steam generator to be controlled by the temperature sensor if more than the constant.

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