JP6326899B2 - Evaporator - Google Patents

Description

  The present invention relates to an evaporator.

  Conventionally, a heat cycle system using an adsorption heat pump has been used in various fields, and is applied to an air conditioner or a water heater.

  The adsorption type heat pumps proposed so far are generally provided with a pair of adsorbers, a condenser and an evaporator (see, for example, Patent Document 1), and heat increase to increase COP (Coefficient Of Performance). As an example using the mode, an adsorption heat pump type water heater has been proposed (for example, see Non-Patent Document 1). In this system, switching of the operation mode and hot water supply operation are usually performed by switching the flow path using a three-way valve. Specifically, an operation of adsorbing fluid on one side of the adsorber and desorbing the other (that is, regeneration of the adsorber) and an operation of desorbing fluid from the one adsorber and adsorbing to the other are switched. Alternately.

  In addition, an aqueous adsorption heat pump that operates in the same manner as described above is also known (see, for example, Non-Patent Document 2).

  The water-based adsorption heat pump described in Non-Patent Document 2 is a typical application example in which an evaporator is driven in a reduced pressure field. In many cases, a falling liquid film evaporator is often used because it is difficult to cause boiling.

JP 2006-125713 A

"24th Technology Development and Survey Project Results Presentation [P5.1.2] Development of high-efficiency kerosene combustion equipment using adsorption heat pump", [online], June 2010, Petroleum Energy Technology Center, [March 14, 2014 search], Internet <URL: http: //www.pecj.or.jp/japanese/report/2010report/24data/p512.pdf> "Adsorption refrigeration machine of union industry", [online], Union Sangyo Co., Ltd., [Search March 14, 2014], Internet <URL: http: //www.union-reitouki. com / chiller / principle.html>

  In the above water-based adsorption heat pump, the phase change medium saturation pressure in the evaporator is generally 0.9 kPa or less (saturation temperature 5 ° C. or less), and the boiling start superheat degree is 20 K or more (4 to 4 in an atmospheric pressure environment). 10K). Therefore, boiling does not occur at the heat medium temperature of about 25 ° C.

  In the case of a falling liquid film evaporator, there is a problem that a pump for spraying the phase change medium onto the heat transfer surface is necessary and the overall size is increased.

  The present invention has been made in view of the above, and an object of the present invention is to provide an evaporator capable of promoting vaporization of a fluid even in a reduced pressure environment of a phase change medium, and to achieve the object. Is an issue.

  The present invention has been achieved based on the following findings. That is, in the evaporator, the boiling start superheat degree is greater in the reduced pressure field than in the atmospheric pressure field. Therefore, as the heat medium temperature decreases, the phase change mode of the phase change medium transitions from boiling on the wall surface to evaporating from the gas-liquid interface, and thus the heat transfer efficiency decreases rapidly. Therefore, a bubble is generated by flowing a heating medium having a temperature that satisfies the boiling start superheat degree to the boiling promotion heat medium flow path, and the gas-liquid on the heat transfer surface of the heat generation flow path for cold heat generation is generated by the bubbles. It is a finding that it is possible to increase the interface area and improve the heat transfer efficiency.

  In order to achieve the above object, an evaporator according to the present invention includes a phase change medium flow path for vaporizing a fluid, and a heat generating medium for cooling generation cooled by heat of vaporization downstream of the phase change medium flow path. A heating medium flow path for generating cold heat, and a heating medium flow path for boiling promotion for circulating a heating medium for heating the upstream side of the phase change medium flow path, the heating medium flow path for boiling promotion Is connected to a heat source having a temperature exceeding the boiling start superheat degree of the fluid.

  In the present invention, the evaporator includes a first evaporator having the phase change medium flow path and the cold medium generating heat medium flow path, a first evaporator having the phase change medium flow path and the boiling promotion heat medium flow path. And the phase change medium flow path of the first evaporator and the phase change medium flow path of the second evaporator may be connected in series.

  In the present invention, the heat medium flow path for generating cold heat and the heat transfer medium flow path for boiling promotion can be spatially separated.

  In the present invention, the amount of heat transfer between the cold heat generating heat medium passage and the boiling promotion heat medium flow path is 50% or less with respect to the cold output by the cold heat generating heat medium. In the present invention, the amount of heat transfer between the cooling medium generating heat medium channel and the boiling promotion heating medium channel is 10% or less with respect to the cooling power output by the cooling medium generating heat medium.

  In the present invention, the downstream of the phase change medium flow path is connected to a reactor containing a physical adsorbent or a chemical heat storage material via a pipe, and by the pressure reducing action of the physical adsorbent or the chemical heat storage material. A reduced pressure environment of the phase change medium flow path can be formed.

  The fluid can be water.

  ADVANTAGE OF THE INVENTION According to this invention, the evaporator which can accelerate | stimulate vaporization of a fluid is provided even in the pressure reduction environment of a phase change medium.

It is the schematic which shows the structural example of the chemical heat pump of 1st Embodiment of this invention. It is a perspective view which shows the specific structural example of an evaporator. It is AA 'sectional drawing of an evaporator. It is BB 'sectional drawing of an evaporator. It is a graph which shows the relationship between a boiling start superheat degree and the output per area. It is the figure which showed typically the evaporator of the chemical heat pump of 2nd Embodiment of this invention.

  Hereinafter, an embodiment in which the evaporator of the present invention is applied to a chemical heat pump will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments shown below.

(First embodiment)
A chemical heat pump according to a first embodiment of the present invention will be described with reference to FIGS. In this embodiment, silica gel is used as the physical adsorbent for the adsorber, calcium oxide (CaO) is used as the chemical heat storage material for the heat storage reactor, and water vapor (water) is used as the fluid supplied to the adsorber and the heat storage reactor. A chemical heat pump (hereinafter also simply referred to as “heat pump”) will be described in detail as an example.

  As shown in FIG. 1, the heat pump 100 according to the present embodiment includes an evaporator 10, an adsorber 20 having a physical adsorbent, and a chemical heat accumulator, and a heat storage function serving as a heater for steam heating the adsorber. A reactor 30 and a condenser 40 that condenses the fluid (water vapor) discharged from the adsorber 20 are provided.

  The evaporator 10 is connected to the adsorber 20 and the heat storage reactor 30 so as to be capable of supplying water vapor, which is a fluid generated by vaporizing water. Specifically, the evaporator 10 is connected to one end of a flow pipe 12 having a valve V4 that is a flow control valve and one end of a flow pipe 14 having a valve V5 that is a flow control valve, respectively. The evaporator 10 is communicated with the adsorber 20 via the circulation pipe 12 and is communicated with the heat storage reactor 30 via the circulation pipe 14.

  The evaporator 10 is used when the amount of water adsorbed in the chemical heat storage material disposed in the reaction chamber of the heat storage reactor 30 does not reach the saturation amount, or when adsorbed by a fluid holding unit provided in the adsorber 20 as described later. When the amount of water vapor adsorbed on the material decreases, the vaporization of water in the evaporator 10 proceeds and is supplied to the distribution pipes 12 and 14 as water vapor. Moreover, water is heated with the heat from the outside, and is discharged | emitted to the distribution piping 12 and 14 as water vapor | steam.

  Specifically, as shown in FIGS. 2 and 3, the evaporator 10 includes a plurality of phase change medium flow paths 32, a plurality of cold heat generation heat medium flow paths 34, and a plurality of boiling promotion heat medium flow paths. 36 is provided. The phase change medium flow path 32, the cooling medium generating heat medium path 34, and the boiling promoting heat medium path 36 are alternately arranged in the housing of the evaporator 10, and the adjacent phase change medium flow path 32 and the cooling heat are arranged. The generation heat medium flow path 34, the adjacent phase change medium flow path 32, and the boiling promotion heat medium flow path 36 are thermally connected to each other. In this embodiment, the evaporator 10 includes an opening direction of the phase change medium flow path 32 (a flow direction of water vapor), and an opening direction of the cold heat generation heat medium flow path 34 and the boiling promotion heat medium flow path 36 (heat medium). In the side view).

  The evaporator according to the present invention has two or more phase change medium flow paths 32 as in the example of the evaporator 10, and the cold medium generating heat medium path 34 and the boiling promotion heat medium path 36 are at least phase change. The configuration is preferably arranged between the medium flow paths 32, and the two or more phase change medium flow paths 32, the two or more cold heat generating heat medium flow paths 34, and the boiling promotion heat medium flow path 36 are provided. More preferably, the phase change medium flow path 32, the cooling medium generating heat medium path 34, and the boiling promotion heat medium path 36 are alternately arranged.

  The cold heat generating heat medium flow path 34 is arranged on the downstream side of the phase change medium flow path 32, and distributes the cold heat generating heat medium cooled by the heat of vaporization on the downstream side of the phase change medium flow path 32.

  Boiling promoting heat medium flow path 36 is arranged on the upstream side of phase change medium flow path 32, and circulates a heat medium for heating the upstream side of phase change medium flow path 32. Further, the distribution pipe 50 connected to the upstream side of the boiling promotion heat medium flow path 36 is connected to a heat source having a temperature exceeding the boiling start superheat degree of the phase change medium (water) flowing through the phase change medium flow path 32. ing.

  The boiling promotion heat medium passage 36 and the distribution pipe 50 are connected via a manifold 60 that communicates the plurality of boiling promotion heat medium passages 36 and the distribution pipe 50 in the evaporator 10 in an airtight state. ing.

  Further, the heat medium is discharged from the distribution pipe 52 connected to the downstream side of the boiling promotion heat medium flow path 36. The boiling promotion heat medium flow path 36 and the distribution pipe 52 are connected via a manifold 62 that communicates the plurality of boiling promotion heat medium flow paths 36 and the distribution pipe 52 in the evaporator 10 in an airtight state. .

  Further, the heat generating medium for cold heat flows from the distribution pipe 54 connected to the upstream side of the heat medium flow path 34 for generating cold heat. The cold heat generating heat medium flow path 34 and the distribution pipe 54 are connected via a manifold 64 that communicates the plurality of cold heat generation heat medium flow paths 34 and the distribution pipe 54 in the evaporator 10 in an airtight state. .

  Further, the cooling medium generating heat medium is discharged from the distribution pipe 56 connected to the downstream side of the cooling medium generating heat medium passage 34. The cold heat generation heat medium flow path 34 and the distribution pipe 56 are connected via a manifold 66 that communicates the plurality of cold heat generation heat medium flow paths 34 and the distribution pipe 56 in the evaporator 10 in an airtight state. .

  Further, as shown in FIG. 3, in the evaporator 10, the cooling medium generating heat medium passage 34 and the boiling promotion heating medium passage 36 are integrally formed, and the cooling heat generation heat is formed. The medium flow path 34 and the boiling promotion heat medium flow path 36 are configured to be spatially separated. In addition, the amount of heat transfer between the cooling medium generating heat medium channel 34 and the boiling promotion heating medium channel 36 is 50% or less, preferably 10% or less with respect to the cooling output by the cooling medium generating heat medium. It is comprised so that it may become.

  Next, an example of vaporization of the phase change medium performed in the evaporator 10 will be described with reference to FIG.

  First, when the phase change medium (water) supplied from the distribution pipe 44 flows into the phase change medium flow path 32 and flows through the upstream side in the phase change medium flow path 32, the boiling medium heat medium flow path. By heat exchange with the 36 heat transfer surfaces, the phase change medium boils and bubbles are generated. When the liquid phase change medium and the bubbles are mixed, the area of the gas-liquid interface is enlarged when flowing through the downstream side in the phase change medium flow path 32, so that evaporation is promoted. The phase change medium is vaporized, and the heat of vaporization at this time is heat-exchanged with the heat transfer surface of the cold medium generating heat medium passage 34 to cool the cold medium generating heat medium.

  FIG. 5 is a graph showing the relationship between the boiling start superheat degree of water as the phase change medium and the output per area of the heat transfer surface in a reduced pressure environment in the phase change medium flow path 32. For example, as shown in FIG. 5 above, when the saturation pressure in the phase change medium flow path 32 is 1.8 kPa (saturation temperature 15 ° C.), boiling occurs when the heat medium inflow temperature is 25 ° C. It does n’t start. Therefore, the heat generating medium having a heat medium inflow temperature of 25 ° C. is boiled by heat exchange with the heat transfer surface of the heat medium flow path 36 for boiling promotion having a heat medium inflow temperature of 40 ° C. Evaporation is also promoted on the heat transfer surface of the flow path 34.

  Thus, conventionally, by controlling the temperature of a part of the heat transfer surface in a reduced pressure environment where boiling does not occur, boiling can be promoted and heat transfer efficiency can be improved.

  Since the evaporator 10 takes away the heat of vaporization by vaporizing the phase change medium as described above, cold heat corresponding to the heat of vaporization of water vapor is generated in the cold medium generating heat medium passage 34 of the evaporator 10. Therefore, it is possible to effectively use cold energy by thermally connecting a cooling device such as an air conditioner outdoor unit, which is an example of cold energy demand, through a heat exchange pipe, for example.

  The adsorber 20 is supplied with water vapor from the evaporator 10, adsorbs and holds the water vapor, desorbs and releases the adsorbed water vapor, and the heat storage reactor 30 supplies the water vapor. A second fluid holding unit is provided that condenses and holds the water vapor and desorbs and releases the condensed water vapor again as water vapor.

  The heat storage reactor 30 is supplied with water vapor from the evaporator 10, releases heat of reaction when the water vapor is fixed by a hydration reaction, and has a chemical heat storage material that stores heat when the water vapor is desorbed. And a vaporization chamber that is a fluid vaporization unit that is supplied with water from the condenser 40 and vaporizes water with heat from the reaction chamber. Each of the reaction chamber and the vaporization chamber is alternately arranged in the housing of the heat storage reactor 30, and adjacent chambers are thermally connected to each other.

  The condenser 40 is connected so as to be able to supply water vapor from the adsorber 20, and condenses the water vapor supplied from the adsorber 20. Specifically, one end of a distribution pipe 28 having a valve V3 that is a flow control valve and one end of a flow pipe 29 having a valve V1 that is a flow control valve are connected to the condenser 40, respectively. The condenser 40 communicates with the first fluid holding chamber of the adsorber 20 through the circulation pipe 28 and also communicates with the second fluid holding chamber of the adsorber 20 through the circulation pipe 29. The water vapor discharged from the fluid holding chamber and the second fluid holding chamber through the distribution pipes is collected in one condenser.

  In addition, one end of a circulation pipe 42 having a pump P1 is connected to the condenser 40, and the condenser is communicated with the vaporization chamber of the heat storage reactor 30 by the circulation pipe 42. The water that is condensed and liquefied by the condenser 40 is sent to the vaporization chamber of the heat storage reactor 30 through the distribution pipe 42 by driving the pump P1, and steam is generated in the vaporization chamber. The water vapor generated here is used to heat the adsorber 20 with water vapor.

  Furthermore, one end of a circulation pipe 44 having a pump P2 is connected to the condenser 40, and the condenser 40 and the evaporator 10 are communicated with each other by the circulation pipe 44. The water condensed in the condenser 40 is also supplied to the evaporator 10 through the distribution pipe 44 by driving the pump P2. The water supplied to the evaporator is sent to the reaction chamber of the heat storage reactor 30 as water vapor, and the sent water vapor is adsorbed by the chemical heat storage material and used to generate heat that promotes vaporization of water in the vaporization chamber.

  The control device 90 is a control means that takes full control of the chemical heat pump, and is electrically connected to the valves V1 to V5, the pumps P1 to P2, and an external heat source, and controls the valves, pumps, heat sources, and heat exchange. It is configured to control heat utilization.

  Next, in the chemical heat pump 100 of this embodiment, the operation | movement which supplies a water vapor | steam alternately to the fluid holding | maintenance chamber of the adsorber 20, continues a thermal increase cycle, and collect | recovers thermal energy is demonstrated.

  First, adsorption of water vapor by the physical adsorbent of the adsorber 20 is started. At this time, adsorption heat is generated by adsorption of water vapor, and the second fluid holding chamber capable of heat exchange is heated. Further, the reduced pressure environment of the phase change medium flow path 32 is formed by the pressure reducing action of the physical adsorbent of the adsorber 20, but as described above, evaporation of water in the phase change medium flow path 32 also under the reduced pressure environment. Is promoted and water vapor is supplied, so that the second fluid holding chamber is heated.

  Further, in the second fluid holding chamber heated by exchanging heat of adsorption from the first fluid holding chamber, water is vaporized and desorbed as water vapor, and the water vapor is sent to the condenser 40 through the distribution pipe 29. .

  Next, heated water vapor is supplied from the heat storage reactor 30 to desorb the water adsorbed on the physical adsorbent of the adsorber 20 and regenerate the physical adsorbent. At this time, the water vapor generated in the evaporator 10 is sent to the reaction chamber of the heat storage reactor 30 through the distribution pipe 14. The sent water vapor hydrates with the chemical heat storage material to generate reaction heat. In addition, the depressurization action of the chemical heat storage material of the heat storage reactor 30 forms a depressurization environment of the phase change medium flow path 32. As described above, water in the phase change medium flow path 32 is also present under the depressurization environment. Since evaporation is promoted and water vapor is supplied, the hydration reaction of the chemical heat storage material in the reaction chamber is performed. When the heat of reaction is exchanged with the vaporizing chamber, the water in the vaporizing chamber is vaporized with heat to generate high-temperature steam. When this high-temperature steam is sent to the second fluid holding chamber of the adsorber 20 through the distribution pipe 38, the heat of the steam is exchanged to heat the adsorbent in the first fluid holding chamber, and the steam is heated to the second fluid holding chamber. It is held by condensing in the fluid holding chamber and changing into a liquid phase, and further releases heat of condensation. The water adsorbed on the physical adsorbent in the first fluid holding chamber is desorbed as water vapor, and the desorbed water vapor is sent to the condenser 40 through the distribution pipe 28.

  As described above, according to the first embodiment of the chemical heat pump of the present invention, even under the reduced pressure environment of the phase change medium due to the reduced pressure action of the adsorber and the heat storage reactor, the boiling is promoted and bubbles are generated. By expanding the area of the gas-liquid interface, the heat transfer efficiency can be improved, and the vaporization of the phase change medium can be promoted.

(Second Embodiment)
A second embodiment of the chemical heat pump of the present invention will be described with reference to FIG. This embodiment has a system configuration in which two evaporators are connected in series.

  In addition, in 2nd Embodiment of a chemical heat pump, about the part used as the same component as said 1st Embodiment, the same referential mark is attached | subjected and the detailed description is abbreviate | omitted.

  In the heat pump of this embodiment, as shown in FIG. 6, the first evaporator 10 </ b> A having the phase change medium flow path 32 and the cold medium generating heat medium flow path 34, the phase change medium flow path 32, and the boiling promotion heat medium. And a second evaporator 10 </ b> A having a flow path 36. The phase change medium flow path 32 of the first evaporator 10A and the phase change medium flow path 32 of the second evaporator 10B are connected in series so that the phase change medium flow path 32 of the first evaporator 10A is on the upstream side. Has been.

  When the phase change medium, which is a liquid, flows into the phase change medium flow path 32 of the second evaporator 10B and flows through the phase change medium flow path 32 of the second evaporator 10B, bubbles are generated, and the liquid A phase change medium and bubbles are mixed and flow into the phase change medium flow path 32 of the first evaporator 10A. When the first evaporator 10A flows through the phase change medium flow path 32, the area of the gas-liquid interface is enlarged, so that evaporation is promoted and the vaporized phase change medium is converted into the first evaporator. 10A is supplied to the outside.

  Since the other structure of 2nd Embodiment of a chemical heat pump is the same as that of 1st Embodiment, description is abbreviate | omitted.

  In the above embodiment, the case where the evaporator according to the present invention is applied to a chemical heat pump has been described as an example. However, the present invention is not limited to this, and the evaporator according to the present invention is applied to other than the chemical heat pump. May be.

DESCRIPTION OF SYMBOLS 10 Evaporator 10A 1st evaporator 10B 2nd evaporator 20 Adsorber 30 Thermal storage reactor 32 Phase change medium flow path 34 Cold-heat generation heat medium flow path 36 Boiling promotion heat medium flow path 40 Condenser 90 Controller 100 Chemical heat pump

Claims (5)

A phase change medium flow path for vaporizing the fluid;
A cooling medium generating heat medium flow path for circulating a cooling medium for generating cold heat that is cooled by heat of vaporization downstream of the phase change medium channel;
A boiling-acceleration heat medium flow path for circulating a heat medium for heating the upstream side of the phase change medium flow path,
An evaporator connected to a heat source at a temperature higher than a boiling start superheat degree of the fluid, upstream of the boiling promotion heat medium flow path ,
The evaporator includes a first evaporator having the phase change medium flow path and the cooling medium generating heat medium flow path, a second evaporator having the phase change medium flow path and the boiling promotion heat medium flow path, and The phase change medium flow path of the first evaporator and the phase change medium flow path of the second evaporator are connected in series,
The evaporator in which the amount of heat transfer between the heat medium flow path for cold heat generation and the heat medium flow path for boiling promotion is 50% or less with respect to the cold heat output by the heat medium for cold heat generation . A phase change medium flow path for vaporizing the fluid;
A cooling medium generating heat medium flow path for circulating a cooling medium for generating cold heat that is cooled by heat of vaporization downstream of the phase change medium channel;
A boiling-acceleration heat medium flow path for circulating a heat medium for heating the upstream side of the phase change medium flow path,
The upstream of the boiling promotion heat medium flow path is connected to a heat source having a temperature exceeding the boiling start superheat degree of the fluid ,
The cooling medium for generating heat and the heating medium channel for promoting boiling are spatially separated ,
The evaporator in which the amount of heat transfer between the heat medium flow path for cold heat generation and the heat medium flow path for boiling promotion is 50% or less with respect to the cold heat output by the heat medium for cold heat generation . Amount of heat transfer between the cold-producing heat medium flow path and the boiling promote heat medium flow path, to cold output by the cold-producing heat medium, according to claim 1 or 2, wherein 10% or less Evaporator. A phase change medium flow path for vaporizing the fluid;
A cooling medium generating heat medium flow path for circulating a cooling medium for generating cold heat that is cooled by heat of vaporization downstream of the phase change medium channel;
A boiling-acceleration heat medium flow path for circulating a heat medium for heating the upstream side of the phase change medium flow path,
The upstream of the boiling promotion heat medium flow path is connected to a heat source having a temperature exceeding the boiling start superheat degree of the fluid ,
The downstream of the phase change medium flow path is connected to a reactor containing a physical adsorbent or a chemical heat storage material via a pipe, and the phase change is caused by the pressure reducing action of the physical adsorbent or the chemical heat storage material. An evaporator in which a reduced pressure environment of the medium flow path is formed . The evaporator according to any one of claims 1 to 4 , wherein the fluid is water.

Images