JP6470568B2 - Heat exchanger - Google Patents

Description

  The present invention relates to a heat exchange device.

  2. Description of the Related Art Conventionally, an air temperature type vaporizer that vaporizes a low-temperature liquefied gas such as liquefied natural gas (LNG) by heating it in the atmosphere is known. For example, Patent Literature 1 includes an air temperature type vaporizer, a suction fan device, an air heater, a hot water circulation pump, and a hot water pipe connecting the air warmer and the hot water circulation pump. A low temperature liquefied gas vaporizer is disclosed. The air temperature type vaporizer has a heat exchanger that vaporizes the low-temperature liquefied gas by exchanging heat between the low-temperature liquefied gas and air. The suction fan device forms an air flow that passes through the heat exchanger and heats the low-temperature liquefied gas in the heat exchanger. The air heater is disposed upstream of the air temperature type vaporizer in the air flow, and heats the air flowing into the heat exchanger of the air temperature type vaporizer with hot water. The hot water circulation pump sends hot water heated after flowing out of the air warmer to the air warmer again through the hot water pipe.

JP 2010-203520 A

  In the low-temperature liquefied gas vaporizer as described in Patent Document 1 above, power (power of the hot water circulation pump) and hot water piping are required to heat the airflow flowing into the heat exchanger of the air temperature type vaporizer. Become. This problem is not unique to a device that vaporizes low-temperature liquefied gas by directly heating it in the air in a heat exchanger. For example, this problem can also occur in a heat exchange apparatus that heats an intermediate medium in the atmosphere among apparatuses that vaporize a low-temperature liquefied gas using an intermediate medium such as propane.

  An object of the present invention is to provide a heat exchange device that can reduce power required to heat an airflow flowing into a heat exchanger and can omit a hot water pipe.

As means for solving the above problems, the present invention includes a blower for forming an air flow flowing downward, is disposed from below the blower by the air current flowing in the downward and cold cold medium than air is heat exchanger a heat exchanger for heating said low temperature medium, than the heat exchanger and the blower is disposed above, and a preheating unit for heating the air flow that flows downward toward the heat exchanger, the preheating unit Provided is a heat exchange device having a shape capable of heating the airflow by the radiant heat of sunlight applied to the preheating unit.

In the present invention, since the preheating unit is arranged above the heat exchanger and the blower , the airflow that is a heating medium for heating the low temperature medium in the heat exchanger is applied to the preheating unit before flowing into the heat exchanger. It is heated by the radiant heat of sunlight irradiated to the preheating part. Therefore, unlike the conventional method, it is possible to heat the airflow without requiring power (pump driving force) and hot water piping for heating the airflow flowing into the heat exchanger. Furthermore, since the distance from the downstream end of the heat exchange device to the upstream end is increased by providing the preheating unit, the relatively low temperature air that has flowed out of the heat exchange device is again subjected to the heat exchange. Inflow from the upstream side of the device (so-called short circuit) is suppressed.

  In this case, the preheating part is formed in a cylindrical shape, and a preheating part shape index represented by a value obtained by dividing the length of the preheating part by the diameter of the preheating part is larger than 0 and 1. It may be set within a range of 52 or less.

  If it does in this way, when the said heat exchanging device is used in the area below 30 degrees of latitude, a fan power reduction rate can be increased, suppressing the increase in cost resulting from a preheating part becoming long. The blower power reduction ratio is obtained when the heat exchanger has a preheating portion with respect to the power of the blower necessary for obtaining a predetermined exchange heat amount in the heat exchanger when the preheat portion is not provided. It means the ratio of the amount of power reduction of the blower necessary for the purpose.

  Specifically, as the preheating part shape index (the length of the preheating part) increases, the heating amount of the airflow in the preheating part increases. Therefore, as the preheating part shape index increases, the heat exchanger has a predetermined exchange heat amount. The airflow rate required to obtain That is, an increase in the amount of heating of the airflow leads to a reduction in the power of the blower. In other words, the increase in the preheating part shape index has a factor of increasing the blower power reduction rate. On the other hand, as the preheating portion becomes longer, the pressure loss generated in the preheating portion becomes larger, and the portion where the sunlight is not irradiated to the preheating portion (the portion that becomes a shadow) becomes larger, so the power of the blower increases. . That is, the increase in the preheating part shape index also has a factor of decreasing the blower power reduction rate. At least due to the influence of these factors, the fan power reduction ratio shows a behavior that gradually increases and then decreases as the preheating part shape index increases from 0 and decreases. Specifically, in the region where the latitude is 30 degrees, the blower power reduction ratio becomes the maximum when the preheating part shape index is 1.52. Moreover, about the area | region until a fan power reduction ratio becomes the said maximum, the increment of the fan power reduction ratio with respect to the increment of a preheating part shape parameter | index becomes large, so that the latitude becomes high. On the other hand, naturally, the longer the preheating part, the higher the manufacturing cost of the preheating part. Therefore, when the preheating part shape index is set to be larger than 0 and 1.52 or less, when the heat exchange device is used in an area of latitude 30 degrees or less, the manufacturing cost of the preheating part is significantly increased. It is possible to increase the blower power reduction ratio while suppressing.

  Further, in the present invention, the preheating part is formed in a cylindrical shape, and a preheating part shape index represented by a value obtained by dividing the length of the preheating part by the diameter of the preheating part is 0.24 or more and It may be set within a range of 1.95 or less.

  In this way, when the heat exchange device is used in an area of latitude 10 degrees or more, the heating performance index represented by the value obtained by dividing the exchange heat increase rate by the blower power increase rate is 1.0 or more. Become. The rate of increase in the exchange heat amount means the ratio of the increase in the exchange heat amount in the heat exchanger with the preheating part to the exchange heat amount in the heat exchanger without the preheating part. The fan power increase rate is the amount of increase in the power of the blower necessary to obtain the predetermined air volume when the preheating part is provided with respect to the power of the fan required to obtain the predetermined air quantity when the preheating part is not provided. Means the percentage of In other words, the heating performance index being 1.0 or more means that the rate of increase in the amount of exchange heat in the heat exchanger by providing the preheating unit is greater than the rate of increase in power of the blower by providing the preheating unit. Means more. Therefore, by setting the preheating part shape index within the range of 0.24 or more and 1.95 or less, the air flow necessary for obtaining the same exchange heat quantity as the exchange heat quantity in the heat exchanger when there is no preheating part. Since the air volume of the fan is reduced, the power of the blower is reduced.

  Moreover, in this invention, it further has the reflection member which reflects sunlight with respect to the said preheating part, The said reflection member is arrange | positioned on the outer side of the said preheating part, The sunlight irradiated to the said reflection member is the said It is preferable to have a shape that reflects the outer surface of the preheating portion.

  In this way, the airflow passing through the preheating portion can be further heated without restricting the passage of the airflow within the preheating portion. Specifically, since the reflecting member is arranged outside the preheating portion, it does not become a resistance of the airflow passing through the preheating portion, and the reflecting member is irradiated not only with sunlight directly irradiated on the preheating portion. Since the reflected sunlight light is effectively applied to the outer surface of the preheating portion, the amount of airflow in the preheating portion is increased.

  In this case, the preheating portion is formed in a cylindrical shape, and the reflection member includes a flat plate-like first reflection plate and a flat plate-like second reflection plate, and the first reflection plate and The second reflector has a vertical direction at an angle obtained by adding 45 degrees to the latitude at which the preheating portion is installed at the lower end portion of the outer surface of the preheating portion at a position sandwiching the preheating portion from both sides in the horizontal direction. In the state where the first reflector and the second reflector are connected to the outer surface of the preheating part, the first reflector and the second reflector are A preheating part shape index represented by a value obtained by dividing the length of the preheating part by the diameter of the preheating part has a shape that overlaps the entire outer surface of the preheating part in the horizontal direction. It may be set within a range of 90 or less.

  In this way, since the reflected light of sunlight irradiated on each reflector is irradiated on the entire outer surface of the preheating unit, the heat exchange device includes an area (latitude 10 or less) including latitude on the equator. Heating performance represented by the value obtained by dividing the rate of increase in exchange heat by the rate of increase in blower power, even when used in regions where the amount of sunlight irradiated to the preheating part is less than in regions above The index becomes 1.0 or more.

  Alternatively, the preheating portion is formed in a cylindrical shape, the reflection member is formed in a hollow and truncated cone shape, and the reflection member is connected to a lower end portion of an outer surface of the preheating portion. And a whole area of the outer surface of the preheating part in the horizontal direction and extending upward along a direction inclined with respect to the vertical direction by an angle obtained by adding 45 degrees to the latitude at which the preheating part is installed from the connection part A preheated portion shape index represented by a value obtained by dividing the length of the preheated portion by the diameter of the preheated portion, within a range of 0.10 or more and 4.90 or less. May be set.

  Even if it does in this way, since the reflected light of the sunlight irradiated to the reflecting member is irradiated to the whole outer surface of the preheating part, the said heat exchange apparatus is used in the area below 10 degrees latitude including on the equator. Even if it is a case, the heating performance parameter | index represented by the value which remove | divided the exchange heat amount increase rate by the air blower power increase rate will be 1.0 or more.

  Moreover, in this invention, it is preferable that the emissivity of the outer surface and inner surface of the said preheating part is set to 0.8-1.0.

  In this way, even if this apparatus is used on the equator where the temperature rising effect of the preheating portion is lower than that of other latitudes, the temperature rising effect of the preheating portion can be obtained.

  As described above, according to the present invention, it is possible to provide a heat exchange device that can reduce the power required to heat the airflow flowing into the heat exchanger and can omit the hot water pipe.

It is a figure which shows the outline of a structure of the low temperature liquefied gas vaporization apparatus of one Embodiment of this invention. It is a figure which shows the modification of a heat exchange apparatus. FIG. 3 is a plan view of FIG. 2. It is a figure which shows the relationship between the emissivity of a preheating part, and the temperature rising effect of a preheating part. It is a figure which shows the relationship between the pre-heating part of a heat exchange apparatus, and sunlight. It is a figure which shows the relationship between the incident angle of sunlight, and a form factor. It is a figure which shows the relationship between the preheating part shape parameter | index L / D and a fan motive power reduction rate. It is a figure which shows the relationship between the preheating part shape parameter | index L / D and the heating performance parameter | index (alpha). It is the elements on larger scale of FIG. It is a figure which shows the relationship between the preheating part shape parameter | index L / D and the heating performance parameter | index (alpha) in the latitude 30 degree | times. It is a figure which shows the relationship between the preheating part shape parameter | index L / D and the heating performance parameter | index (alpha) in the latitude 20 degree | times. It is a figure which shows the relationship between the preheating part shape parameter | index L / D and the heating performance parameter | index (alpha) in the case of having a reflector at 10 degree | times latitude. It is a figure which shows the relationship between the preheating part shape parameter | index L / D and the heating performance parameter | index (alpha) in the case of having a reflecting plate at 10 degrees latitude. It is a figure which shows the relationship between the preheating part shape parameter | index L / D and heating performance parameter | index (alpha) in the case of not having a reflecting plate in an equator. It is a figure which shows the relationship between the preheating part shape parameter | index L / D and the heating performance parameter | index (alpha) in having a reflecting plate in an equator.

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

  FIG. 1 shows a low-temperature liquefied gas vaporizer according to an embodiment of the present invention. This low temperature liquefied gas vaporizer is an apparatus for obtaining natural gas (NG) by vaporizing liquefied natural gas (LNG) which is a low temperature liquefied gas. In addition, this apparatus can vaporize low temperature liquefied gas, such as not only liquefied natural gas but ethylene, liquefied oxygen, liquefied nitrogen.

  As shown in FIG. 1, the low-temperature liquefied gas vaporizer according to the present embodiment performs heat exchange between the low-temperature liquefied gas and the gas flow path 1 through which the gas vaporized thereby flows, and the low-temperature liquefied gas and the intermediate medium 4. Heat that is an evaporator that evaporates at least a part of the intermediate medium 4 by exchanging heat between the vaporizer E1 that vaporizes the low-temperature liquefied gas, the circulation passage 6 through which the intermediate medium 4 circulates, and the intermediate medium 4 and the atmosphere. An exchange device E2 and a heating device E3 for heating the gas vaporized by the vaporizer E1 in the atmosphere are provided. That is, the low-temperature liquefied gas vaporizer of this embodiment is an intermediate medium vaporizer. In the present embodiment, propane is used as the intermediate medium 4. The intermediate medium 4 is not limited to propane. For example, propylene, alternative chlorofluorocarbon, etc., which evaporates at room temperature and does not solidify at ordinary temperature (low temperature) (medium having a boiling point lower than the atmospheric temperature) If so, a medium other than propane may be used.

  The vaporizer E <b> 1 is provided in the gas flow path 1. In the present embodiment, the vaporizer E1 is a so-called shell and tube heat exchanger. Specifically, the vaporizer E1 includes an inlet chamber 12 and an outlet chamber 14 that are partitioned from each other by a partition wall, a large number of heat transfer tubes 16 that communicate with the chambers 12 and 14, and a heat exchange chamber that houses the heat transfer tubes 16. 18.

  The inlet chamber 12 is connected to the gas flow path 1. Each heat transfer tube 16 has a substantially U shape, and one end thereof is connected to the inlet chamber 12, and the other end is connected to the outlet chamber 14. Each heat transfer tube 16 is arranged in a posture protruding sideways from the inlet chamber 12 and the outlet chamber 14. The heat exchange chamber 18 is connected to the sides of the chambers 12 and 14. The heat exchange chamber 18 has a shape that receives the intermediate medium 4 from the upper part and allows the intermediate medium 4 to flow out from the lower part. That is, heat exchange between the low-temperature liquefied gas flowing in the heat transfer tube 16 and the intermediate medium 4 flowing outside the heat transfer tube 16 is performed in the heat exchange chamber 18. Specifically, the low-temperature liquefied gas flowing into the inlet chamber 12 from the gas flow path 1 is vaporized (evaporated) by exchanging heat with the intermediate medium 4 in the process of flowing through the heat transfer tubes 16, and the gas flow from the outlet chamber 14. It flows out to the road 1. On the other hand, the intermediate medium 4 flowing out from the heat exchange chamber 18 flows into the circulation channel 6.

  The heat exchange device E2 is provided in the circulation channel 6. The heat exchange device E2 includes a blower 20, a heat exchanger 30, and a preheating unit 40.

  The blower 20 includes a cylindrical blower chamber 22, a fan 24 disposed in the blower chamber 22, and a motor 26 that drives the fan 24. The fan 24 is disposed in a posture that forms an airflow that flows vertically downward when the motor 26 is driven.

  The heat exchanger 30 evaporates at least a part of the intermediate medium 4 by exchanging heat between the downward airflow (atmosphere) formed by the fan 24 and the intermediate medium 4. That is, in the heat exchanger 30, the airflow is used as a heating medium. Specifically, the heat exchanger 30 includes a heat exchange chamber 32 and a heat transfer tube 34 disposed in the heat exchange chamber 32.

  The heat exchange chamber 32 is formed in a rectangular parallelepiped shape (square tube shape). The upper end of the heat exchange chamber 32 is connected to the lower end of the blower chamber 22 via a hollow connecting portion 35. In the present embodiment, the heat exchange chamber 32 is supported by the legs 36 in a posture in which the central axis is parallel to the vertical direction. For this reason, the blower chamber 24 also has a posture in which the central axis is parallel to the vertical direction.

  The heat transfer tube 34 is connected to the circulation flow path 6, and the intermediate medium 4 flows through the inside thereof. Specifically, after flowing out from the heat exchange chamber 18 into the circulation channel 6, the liquid phase intermediate medium 4 pressurized by the pump 7 provided in the circulation channel 6 flows into the heat transfer pipe 34. At least a part of the intermediate medium 4 flowing in the heat transfer tube 34 is evaporated by being heated by the airflow in the heat exchange chamber 32. The intermediate medium 4 that has flowed out of the heat transfer tube 34 into the circulation flow path 6 flows into the heat exchange chamber 18 of the vaporizer E1 from above.

  The preheating unit 40 is disposed on the upstream side of the airflow (downward airflow formed by the fan 24) with respect to the heat exchanger 30, and heats the airflow flowing toward the heat exchanger 30. The preheating unit 40 has a shape capable of heating the airflow by the radiant heat of sunlight applied to the preheating unit 40. In the present embodiment, the preheating unit 40 is formed in a cylindrical shape. More specifically, the preheating part 40 is comprised by steel cylindrical piping. That is, the preheating part 40 heats the airflow which passes the inside by the radiant heat of sunlight with which the outer surface and inner surface are irradiated. The preheating unit 40 has the same diameter as that of the blower chamber 22, and the lower end of the preheating unit 40 is connected to the upper end of the blower chamber 22. For this reason, the rotation of the fan 24 forms an airflow from the upper side of the preheating unit 40 toward the lower side of the heat exchange chamber 32. This airflow is heated by the radiant heat in the process of passing through the preheating unit 40 before heating the intermediate medium 4 in the heat exchanger 30.

  The heating device E3 is provided in a portion of the gas flow path 1 on the downstream side of the vaporizer E1. The heating device E3 is a device that heats the gas vaporized by the vaporizer E1 with the atmosphere. The heating device E3 includes a blower 50 and a heat exchanger 60.

  The structure of the blower 50 is the same as the structure of the blower 20 of the heat exchange device E2. The structure of the heat exchanger 60 is the same as the structure of the heat exchanger 30 of the heat exchange device E2. That is, the gas flowing in the heat transfer tube of the heat exchanger 60 is heated by the downward airflow formed by the fan of the blower 50.

  2 and 3 show a modification of the heat exchange device E2. In this example, a reflection member that reflects sunlight to the preheating portion 40 is connected to the preheating portion 40. This reflecting member has a flat plate-like first reflecting plate 42 and a flat plate-like second reflecting plate 44. The first reflecting plate 42 is formed in a rectangular shape. The second reflector 44 is formed in the same shape as the first reflector 42. Both reflection plates 42 and 44 are connected to the lower end of the outer surface of the preheating unit 40 at a position where the preheating unit 40 is sandwiched from both sides in the horizontal direction. Each of the reflectors 42 and 44 is connected to the outer surface of the preheating unit 40 in an attitude that is inclined by an angle of 45 degrees to the latitude at which the preheating unit 40 is installed with respect to the vertical direction and whose bottom is parallel to the horizontal. Has been. The reflecting plates 42 and 44 are arranged in the direction in which the reflecting plates 42 and 44 are arranged in a state where the reflecting plates 42 and 44 are connected to the outer surface of the preheating unit 40 (hereinafter referred to as “connected state”) (see FIG. 2 and the left and right direction in FIG. 3) has a shape overlapping with the outer surface of the preheating portion 40. Specifically, the dimension in the direction (vertical direction in FIG. 3) orthogonal to both the alignment direction and the vertical direction in the connected state of the reflecting plates 42 and 44 is set to be the same as the diameter D of the preheating unit 40. Yes. Moreover, the height dimension in the said connection state of each reflector 42,44 is set to the same as the length L of the preheating part 40. FIG. However, the height dimension of the reflecting plates 42 and 44 is not limited to the same as the length L of the preheating unit 40. For example, the height dimension of the reflectors 42 and 44 may be set to about half of the length L.

  Next, the relationship between the emissivity (absorption rate) of the outer surface and the inner surface of the preheating unit 40 and the increase value of the surface temperature of the preheating unit 40 will be described with reference to FIG. The increase value of the surface temperature of the preheating part 40 mainly includes the sunshine duration, the irradiation area ratio φ (the ratio of the area of the preheating part 40 to which the sunlight irradiates) and the form of the preheating part 40 The coefficient (light receiving efficiency of sunlight) is related. The irradiation area ratio φ and the shape factor will be described later. In FIG. 4, values are shown when the sunshine duration is 6 hours, the irradiation area ratio φ is 100%, and the shape factor of the preheating portion 40 is 0.82.

  As shown in FIG. 4, when the latitude is constant, the increase value (temperature increase effect) of the surface temperature of the preheating unit 40 increases as the emissivity of the surface (outer surface and inner surface) of the preheating unit 40 increases. Further, when the emissivity is constant, the temperature rising effect is the lowest at the equator, and the temperature increasing effect gradually increases as the latitude increases from the equator. In the present embodiment, the emissivity of the surface of the preheating unit 40 is set in a range where the increase value of the surface temperature of the preheating unit 40 at the equator is larger than 0, that is, 0.8 or more and 1.0 or less. . Specifically, the surface of the preheating part 40 is set to a color (black or the like) having an emissivity of 0.8 or more and 1.0 or less.

  Here, the irradiation area ratio φ will be described with reference to FIG.

  When sunlight having a predetermined incident angle θ is irradiated to the preheating unit 40, a portion (hereinafter referred to as “non-irradiation unit”) that is shaded without being irradiated with sunlight is generated in the preheating unit 40. When the length L1 of the non-irradiated portion is 0, the irradiated area ratio φ is 100%. That is, when the irradiation area ratio φ is 100%, the heating effect of the preheating portion 40 is maximized. Here, the irradiation area ratio φ is expressed by the following equation.

  φ = 1-L1 / 2L

  Further, the length L1 of the non-irradiated part is expressed by the following equation.

  L1 = LD / tan θ

  Therefore, in an area where the latitude is 30 degrees (θ = 30 °), the value obtained by dividing the length L of the preheating portion 40 by the diameter D of the preheating portion 40 (hereinafter referred to as “preheating portion shape index L / D”) is 1. When the ratio is 0.7 or less, the irradiation area ratio φ is 100%. Similarly, in an area where the latitude is 20 degrees (θ = 20 °), the irradiation area ratio φ is 100% when the preheating portion shape index L / D is 2.7 or less, and the latitude is 10 degrees (θ = 10 °). ), The irradiation area ratio φ is 100% when the preheated portion shape index L / D is 5.7 or less.

  Next, the form factor will be described with reference to FIG.

  As shown in FIG. 6, the view factor changes according to the incident angle θ of sunlight to the preheating unit 40 (see FIG. 5). The incident angle θ is equal to the latitude at which the preheating unit 40 is installed. As shown in FIG. 6, when the incident angle θ is 0 ° (on the equator), the form factor is 0.5, and when the incident angle θ is 90 °, the form factor is 1.0, which is the highest. . The form factor of the non-irradiated part (part of the preheating part 40 where the sunlight is not irradiated) is zero. When the preheating part 40 is cylindrical, since the average value of each value of FIG. 6 becomes a form factor, the form factor of the preheating part 40 of this embodiment is 0.82.

  Next, the relationship between the preheating part shape index L / D of the preheating part 40 and the blower power reduction ratio will be described with reference to FIG. The fan power reduction ratio means that when the preheater 40 is not provided, the heat exchanger 30 has the preheater 40 with respect to the power of the blower 40 necessary for obtaining a predetermined exchange heat amount. The ratio of the reduction amount of the motive power of the air blower 40 required in order to obtain the amount of exchange heat of this. FIG. 7 shows that when the latitude is 30 degrees and the reflectors 42 and 44 are not provided, when the latitude is 20 degrees and the reflectors 42 and 44 are not provided, the latitude is 10 degrees and the reflectors 42 and 44 are provided. When the latitude is 10 degrees and both reflectors 42 and 44 are provided, when the reflectors 42 and 44 are not provided on the equator, and when both reflectors 42 and 44 are provided on the equator, It is shown. Note that these values are values when the Reynolds number Re is 1.6 million.

  As shown in FIG. 7, the blower power reduction rate shows a behavior that gradually increases and increases after the preheating part shape index L / D increases from 0 and then decreases. The reason for this is that the increase in the preheating part shape index L / D includes both a factor for increasing the fan power reduction ratio and a factor for decreasing it.

  Specifically, as the preheating part shape index L / D (the length L of the preheating part 40) increases, the amount of heating of the airflow in the preheating part 40 increases, so the preheating part shape index L / D increases. Accordingly, the flow rate of the air flow necessary for obtaining a predetermined amount of exchange heat in the heat exchanger 30 is reduced. That is, an increase in the amount of heating of the airflow leads to a reduction in power of the blower 20. In other words, the increase in the preheating part shape index L / D has a factor of increasing the blower power reduction rate. On the other hand, as the preheating part 40 becomes longer, the pressure loss generated in the preheating part 40 becomes larger, and the part (non-irradiation part) where the sunlight is not irradiated on the preheating part 40 becomes larger. Will increase. That is, the increase in the preheating part shape index L / D also has a factor of reducing the blower power reduction rate. At least due to the influence of these factors, the fan power reduction ratio shows a behavior that gradually increases and increases after the preheating part shape index L / D increases from 0 and then decreases. For example, in the region where the latitude is 30 degrees, the blower power reduction ratio is the maximum when the preheating part shape index L / D is 1.52, and the value is 36%.

  Further, as shown in FIG. 7, the region until the fan power reduction rate when the latitude is 30 degrees reaches the maximum (the region where the preheating part shape index L / D is 1.52 or less) is on the equator. Except for the case where both reflectors 42 and 44 are provided, the increase in the fan power reduction ratio with respect to the increase in the preheating portion shape index L / D increases as the latitude increases. On the other hand, naturally, the longer the preheating unit 40 is, the higher the manufacturing cost of the preheating unit 40 is. Therefore, the preheating part shape index L / D may be set to be larger than 0 and 1.52 or less. If it does in this way, when the said heat exchanging device E2 is used in the area below 30 degrees of latitude, it can enlarge a fan power reduction ratio, suppressing the remarkable increase in the manufacturing cost of the preheating part 40. FIG.

  Next, the relationship between the preheating part shape index L / D and the heating performance index α represented by the value obtained by dividing the exchange heat amount increase rate by the blower power increase rate will be described with reference to FIGS. 8 and 9. . The rate of increase in the exchange heat amount means the ratio of the increase in the exchange heat amount in the heat exchanger 30 with the preheating unit 40 to the exchange heat amount in the heat exchanger 30 when the preheating unit 40 is not provided. The fan power increase rate is the ratio of the fan 20 necessary for obtaining the predetermined air volume when the preheater 40 is provided to the power of the fan 20 necessary for obtaining the predetermined airflow when the preheater 40 is not provided. It means the rate of increase in power. That is, that the heating performance index α is 1.0 or more means that the amount of heat exchanged in the heat exchanger 30 by providing the preheating unit 40 is larger than the rate of increase in power of the blower 20 by providing the preheating unit 40. It means that the ratio is higher. In addition, FIG. 9 is the figure which expanded the range from 0 to 2.00 in the preheating part shape parameter | index L / D in FIG. 8 and 9, when the latitude is 30 degrees and the reflectors 42 and 44 are not included, when the latitude is 20 degrees and the reflectors 42 and 44 are not included, the latitude is 10 degrees and the reflectors 42 and 44 are not included. When there is no reflector 44, when the latitude is 10 degrees and both reflectors 42 and 44 are present, when both reflectors 42 and 44 are not present on the equator, and when both reflectors 42 and 44 are present on the equator Each value is shown. These values are values when the Reynolds number Re is 1.6 million (during rated operation). In this embodiment, the Reynolds number Re can be operated in the range of 1.1 million to 2.2 million.

  As shown in FIGS. 8 and 9, when the reflectors 42 and 44 are not provided in an area where the latitude is 10 degrees to 30 degrees, the heating performance during rated operation (when the Reynolds number Re is 1.6 million). The index α is 1.0 or more when the preheating portion shape index L / D is in the range of at least 0.24 to 1.95. Therefore, when both the reflectors 42 and 44 are not provided in an area where the latitude is 10 degrees to 30 degrees, it is preferable that the preheating part shape index L / D is set in a range of 0.24 to 1.95. More preferably, preheating part shape parameter | index L / D is set to the range of 0.60-1.09. In this way, the heating performance index α is 1.1 or more.

  In the case of having both reflectors 42 and 44 as in the modification shown in FIGS. 2 and 3, during rated operation (when the Reynolds number Re is 1.6 million), the heating performance index α is the shape of the preheating part. When the index L / D is at least in the range of 0.1 to 4.9, it becomes 1.0 or more. Therefore, when it has both the reflectors 42 and 44 in the area whose latitude is 10 degrees or less, it is preferable that the preheating part shape parameter | index L / D is set to this range.

  The above is appropriate when the Reynolds number Re is 1.6 million. If the Reynolds number Re changes, the range of the preheating part shape index L / D in which the heating performance index α is 1.0 or more also changes. This point will be described below with reference to FIGS.

  10 to 15 show values when the Reynolds number Re is 1.1 million, 1.3 million, 1.6 million, 1.8 million, 2 million and 2.2 million. As shown in these figures, the heating performance index α gradually increases as the Reynolds number Re decreases. That is, as the Reynolds number Re decreases, the range of the preheated portion shape index L / D in which the heating performance index α is 1.0 or more increases.

  FIG. 10 shows the relationship between the preheating part shape index L / D and the heating performance index α in the case where the reflectors 42 and 44 are not provided in an area where the latitude is 30 degrees. As shown in FIG. 10, when the Reynolds number Re is 1.6 million, the heating performance index α is 1.0 or more when the preheating part shape index L / D is in the range of 0.08 to 2.80. Become. However, as described above, when the Reynolds number Re is smaller than 1.6 million, the range of the preheating portion shape index L / D where the heating performance index α is 1.0 or more is larger than the above range. On the other hand, when the Reynolds number Re is larger than 1.6 million, the range of the preheating part shape index L / D where the heating performance index α is 1.0 or more is smaller than the above range. This tendency is the same regardless of the latitude and the presence or absence of both reflectors 42 and 44.

  FIG. 11 shows the relationship between the preheating part shape index L / D and the heating performance index α in a region where the latitude is 20 degrees and the reflectors 42 and 44 are not provided. As shown in FIG. 11, when the Reynolds number Re is 1.6 million, the heating performance index α is 1.0 or more when the preheating part shape index L / D is 0.10 or more. In addition, when the Reynolds number Re is 1.6 million, the upper limit value of the range of the preheating part shape index L / D where the heating performance index α is 1.0 or more is 3.13. When the preheating part shape index L / D is in the range of 0.10 to 3.13, the heating performance index α is 1.0 or more.

  FIG. 12 shows the relationship between the preheating portion shape index L / D and the heating performance index α in the case where the reflectors 42 and 44 are not provided in an area where the latitude is 10 degrees. As shown in FIG. 12, when the Reynolds number Re is 1.6 million, the heating performance index α is 1.0 or more when the preheating part shape index L / D is in the range of 0.24 to 1.95. Become.

  FIG. 13 shows the relationship between the preheating part shape index L / D and the heating performance index α when both the reflectors 42 and 44 are provided in an area where the latitude is 10 degrees. As shown in FIG. 13, when the Reynolds number Re is 1.6 million, the heating performance index α is 1.0 or more when the preheating part shape index L / D is 0.10 or more. When the Reynolds number Re is 1.6 million, the upper limit value of the range of the preheating part shape index L / D where the heating performance index α is 1.0 or more is 5.00.

  FIG. 14 shows the relationship between the preheating part shape index L / D and the heating performance index α when the reflectors 42 and 44 are not provided in the region on the equator. As shown in FIG. 14, when the reflector 42 is not provided in the region on the equator, there is no preheating part shape index L / D where the heating performance index α is 1.0 or more regardless of the Reynolds number Re.

  FIG. 15 shows the relationship between the preheating part shape index L / D and the heating performance index α when both reflectors 42 and 44 are provided in the region on the equator. As shown in FIG. 15, when the Reynolds number Re is 1.6 million, the heating performance index α is 1.0 or more when the preheating part shape index L / D is 0.03 or more. When the Reynolds number Re is 1.6 million, the upper limit value of the range of the preheated portion shape index L / D where the heating performance index α is 1.0 or more is 55.0.

  Next, the operation of the low-temperature liquefied gas vaporizer will be described.

  The low-temperature liquefied gas (LNG in this embodiment) that has flowed into the inlet chamber 12 of the vaporizer E <b> 1 through the gas flow path 1 is vaporized by exchanging heat with the intermediate medium 4 in the heat exchange chamber 18. And the gas which flowed out from the exit chamber 14 of the vaporizer | carburetor E1 is heated by the heating apparatus E3, and reaches outside through the gas flow path 1 after that.

  On the other hand, the intermediate medium 4 flowing out of the heat exchange chamber 18 is heated by the downdraft formed by the blower 20 in the process of flowing through the heat transfer pipe 34 in the heat exchanger 30 of the heat exchange device E2. In this embodiment, since the preheating part 40 is arrange | positioned in the upper end (the upstream of the said airflow rather than the heat exchanger 30) of the air blower chamber 22, it is a heating medium which heats the low-temperature intermediate medium 4 in the heat exchanger 30. A certain airflow is heated by the radiant heat of sunlight irradiated to the preheating unit 40 in the preheating unit 40 before flowing into the heat exchanger 30. Therefore, it becomes possible to heat the airflow without requiring power (such as the driving force of the pump) for heating the airflow flowing into the heat exchanger 30. Furthermore, by providing the preheating part 40, the distance from the downstream end part (lower end part of the heat exchange chamber 32) of the said heat exchange apparatus E2 to an upstream end part (upper end part of the preheating part 40) becomes long. Therefore, the relatively low-temperature air that has flowed out of the heat exchange device E2 is prevented from flowing again from the upstream side of the heat exchange device E2 (so-called short circuit).

  The intermediate medium 4 heated by the heat exchanger 30 flows into the heat exchange chamber 18 through the circulation channel 6.

  Further, by connecting the first reflecting plate 42 and the second reflecting plate 44 to the outside of the preheating unit 40, the airflow passing through the preheating unit 40 can be further reduced without restricting the passage of the airflow in the preheating unit 40. Can be heated. Specifically, since both the reflectors 42 and 44 are disposed outside the preheating unit 40, there is no resistance to the airflow passing through the preheating unit 40, and the sunlight directly irradiated on the preheating unit 40. Not only that, but the reflected light of the sunlight irradiated to both the reflectors 42 and 44 is effectively irradiated to the outer surface of the preheating unit 40, so that the heating amount of the airflow in the preheating unit 40 increases.

  Furthermore, both the reflectors 42 and 44 have a shape that overlaps with the entire area of the outer surface of the preheating part 40 in the direction in which the reflectors 42 and 44 are arranged (the preheating part reflects the reflected light of sunlight irradiated to these reflectors 42 and 44. 40, the area where the heat exchanging device E2 is 10 degrees latitude or less including the equator (light receiving efficiency of sunlight by the preheating unit 40 compared to the area where latitude 10 degrees or more) Even when the preheating part shape index L / D is set within the range of 0.10 or more and 4.90 or less, the heating performance index α is 1. 0 or more.

  Alternatively, when used in an area where the latitude is 10 degrees to 30 degrees, the preheating part shape index L / D is the case where the reflecting member (the first reflecting plate 42 and the second reflecting plate 44) is not provided. By setting it within the range of 0.24 or more and 1.95 or less, the heating performance index α becomes 1.0 or more.

  Further, when the heat exchanging device E2 is used in an area having a latitude of 30 degrees or less, the preheating part 40 is set to a value that is larger than 0 and 1.52 or less in the preheating part shape index L / D. The blower power reduction rate can be increased while suppressing an increase in cost due to the length of 40 being increased.

  Moreover, in this embodiment, since the emissivity of the outer surface and inner surface of the preheating part 40 is 0.8-1.0, the temperature rising effect in the preheating part 40 becomes low compared with other latitudes. Even in the case where the present heat exchanging device E2 is used, the temperature rise effect is obtained in the preheating unit 40.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, the preheating part 40 may be provided in the heating apparatus E3. In this case, the preheating unit 40 is connected to the upper end of the blower 50.

  The low-temperature liquefied gas vaporizer is not limited to the so-called intermediate medium type. That is, the heat transfer tube 34 of the heat exchange device E2 may be connected to the gas flow path 1, and the low-temperature liquefied gas may be directly heated by the atmosphere in the heat exchange device E2.

  Moreover, the shape of the preheating part 40 is not restricted to a cylindrical shape, A polygonal cylinder shape may be sufficient. Moreover, the shape divided | segmented into the circumferential direction may be sufficient.

  Further, the shape of the reflecting member is not limited to the above shape. For example, the reflecting member may be formed in a hollow and truncated cone shape. Specifically, the reflecting member is connected to the lower end portion of the outer surface of the preheating portion 40 and the vertical direction by an angle obtained by adding 45 degrees to the latitude at which the preheating portion 40 is installed from the connection portion. And a reflecting portion that extends upward along the inclined direction and has a shape that overlaps the entire outer surface of the preheating portion 40 in the horizontal direction. Even if it does in this way, since the reflected light of the sunlight irradiated to the reflective member is irradiated to the whole outer surface of the preheating part 40, the said heat exchange apparatus E2 is used in the area below 10 degrees latitude including on the equator. Even if it is a case, the said heating performance parameter | index will be set to 1.0 or more by setting the preheating part shape parameter | index L / D in the range of 0.10 or more and 4.90 or less.

DESCRIPTION OF SYMBOLS 1 Gas flow path 6 Circulation flow path 20 Blower 22 Blower room 24 Fan 26 Motor 30 Heat exchanger 32 Heat exchange chamber 34 Heat exchanger tube 40 Preheating part 50 Blower 60 Heat exchanger E1 Vaporizer E2 Heat exchange apparatus E3 Heating apparatus

Claims (7)

A blower that forms a downwardly flowing airflow;
A heat exchanger that is disposed below the blower and heats the low-temperature medium by exchanging heat between the low-temperature medium lower than the atmosphere and the airflow flowing downward ;
Is disposed above the said heat exchanger and said blower, and a preheating unit for heating the air flow that flows downward toward the heat exchanger,
The said preheating part is a heat exchange apparatus which has a shape which can heat the said airflow with the radiant heat of the sunlight irradiated to the said preheating part. The heat exchange device according to claim 1,
The preheating part is formed in a cylindrical shape,
A heat exchange device, wherein a preheat part shape index represented by a value obtained by dividing the length of the preheat part by the diameter of the preheat part is set in a range larger than 0 and 1.52 or less. The heat exchange device according to claim 1,
The preheating part is formed in a cylindrical shape,
A heat exchange apparatus, wherein a preheat part shape index represented by a value obtained by dividing the length of the preheat part by the diameter of the preheat part is set in a range of 0.24 or more and 1.95 or less. The heat exchange device according to claim 1,
A reflection member that reflects sunlight to the preheating unit;
The said reflection member is arrange | positioned on the outer side of the said preheating part, and has a shape which reflects the sunlight irradiated to the said reflection member with respect to the outer surface of the said preheating part. The heat exchange device according to claim 4,
The preheating part is formed in a cylindrical shape,
The reflection member has a flat plate-like first reflection plate and a flat plate-like second reflection plate,
The first reflecting plate and the second reflecting plate have an angle of 45 degrees to the latitude at which the preheating unit is installed at the lower end of the outer surface of the preheating unit at a position where the preheating unit is sandwiched from both sides in the horizontal direction. It is connected in a posture that is inclined with respect to the vertical direction by the added angle,
In the state where the first reflector and the second reflector are connected to the outer surface of the preheating part, the first reflector and the second reflector are in the horizontal direction and the entire outer surface of the preheating part. Have overlapping shapes,
A heat exchange apparatus, wherein a preheat part shape index represented by a value obtained by dividing the length of the preheat part by the diameter of the preheat part is set in a range of 0.10 or more and 4.90 or less. The heat exchange device according to claim 4,
The preheating part is formed in a cylindrical shape,
The reflecting member is formed in a hollow and truncated cone shape,
The reflecting member is connected to a lower end portion of the outer surface of the preheating portion, and is inclined with respect to the vertical direction by an angle obtained by adding 45 degrees to the latitude at which the preheating portion is installed from the connecting portion. And a reflecting portion that extends upward along the horizontal direction and overlaps with the entire outer surface of the preheating portion in the horizontal direction,
A heat exchange apparatus, wherein a preheat part shape index represented by a value obtained by dividing the length of the preheat part by the diameter of the preheat part is set in a range of 0.10 or more and 4.90 or less. The heat exchange device according to any one of claims 1 to 6,
The emissivity of the outer surface and inner surface of the said preheating part is a heat exchange apparatus set to 0.8-1.0.

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