JP3693582B2 - Dry storage device and method for drying stored product - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dry storage device and a method for drying a stored product, and more particularly to a cooling and dehumidifying dry storage device and a drying method for drying a stored product such as grain.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a dry storage device (dry air generator: DAG) is known in which grains, such as soybeans, onions, garlic, and the like are put in a storage bin, and the storage in the storage bin is dried by cooling and dehumidification. The structure of such a conventional dry storage apparatus is shown in FIG. As shown in FIG. 10, the dry storage device includes a storage bin 401 that stores a stored product 400 such as grain, and a dryer 402 that sends dry air into the storage bin 401. The dryer 402 includes a booster 411 that compresses the refrigerant, a condenser 412 that condenses the compressed refrigerant and heats the outside air OA, and depressurizes the condensed refrigerant using the throttle 413, and evaporates the condensed refrigerant to reduce the outside air OA. An evaporator 414 that cools below the dew point temperature and a blower 415 that sends outside air OA to the evaporator 414 are provided. The evaporator 414 cools the outside air OA below the dew point and removes moisture in the outside air OA. The outside air OA cooled below the dew point is heated by the condenser 412 and supplied to the storage bottle 401. The booster 411, the condenser 412, the throttle 413, and the evaporator 414 constitute a heat pump HP that pumps heat from the outside air OA flowing through the evaporator 414 to the outside air OA flowing through the condenser 412.
[0003]
FIG. 11 is a moist air diagram showing an air conditioning cycle in a conventional dry storage apparatus. In FIG. 11, symbols K to M, OA, and EX correspond to the path states with the respective symbols in FIG. 10. As shown in FIG. 11, in the conventional dry storage device, the outside air OA is sent to the evaporator 414 by the blower 415 (state K). In the evaporator 414, the outside air OA is cooled below the dew point temperature, and the dry bulb temperature is lowered and the absolute humidity is lowered to reach the state L. This state L is on the saturation line in the wet air diagram. The air in the state L is heated by the condenser 412, the dry bulb temperature rises with the absolute humidity being constant, reaches the state M, and is supplied to the storage bin 401. The dry air supplied to the inside of the storage bin 401 increases the absolute humidity by adsorbing moisture in the stored product 400 and lowers the dry bulb temperature by heat of adsorption, and is exhausted from the upper portion of the storage bin 401 (EX). .
[0004]
By using such a dry storage device, it is possible to dry the storage in the storage bottle without overdoing it slowly, and there is no concern about dew condensation during storage drying or a sudden decrease in drying capacity in a thick grain layer. Moreover, since the grain can be dried at a temperature that does not alter the starch quality, it can be stored without impairing the quality of the grain.
[0005]
[Problems to be solved by the invention]
However, in a conventional dry storage device, since the amount of cooling to the dew point is large, about half of the refrigeration effect in the evaporator of the heat pump is consumed to take away the sensible heat load, and the dehumidification capacity per unit of the compressor (dehumidification) Performance) was low.
[0006]
In addition, the amount of heat that reheats the air that has exited the evaporator 414 is the amount of heat released by the condenser 412, and since the amount of heat is not sufficient, the temperature of the air supplied to the storage bin 401 is not very high, and its relative humidity The drying ability was low because of Furthermore, the process of drying the stored matter 400 such as grain in the storage bin 401 is an isenthalpy change, but if the temperature of the supplied air is low, the relative humidity immediately increases, and the unit flow rate of air Therefore, it was necessary to increase the amount of air supplied to the storage bin 401.
[0007]
The present invention has been made in view of such problems of the prior art, and has a high coefficient of operation (COP), a drying storage device with high dehumidifying capacity (dehumidifying performance) per compressor input, and drying of stored items. It aims to provide a method.
[0008]
[Means for Solving the Problems]
In order to solve such problems in the prior art, one aspect of the present invention includes a storage bin in which stored items are stored, a heat transfer tube installed in the storage bin and through which a fluid flows, and a refrigerant. A condenser that condenses the refrigerant and heats the fluid inside the heat transfer tube, an evaporator that evaporates the refrigerant and cools external air to a temperature below the dew point, and the condenser A first heat exchanging means that cools the external air by evaporating the refrigerant at a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator. And a refrigerant path that connects the condenser and the evaporator, and heats the external air by condensing the refrigerant with a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator. 2 heat exchanging means and the first heat exchanging means The evaporator and the second heat exchange means and the said storage bin is a dry storage apparatus characterized by comprising an air path connecting in this order.
[0009]
In another aspect of the present invention, a storage bin in which stored items are stored, a booster that pressurizes the refrigerant, a condenser that condenses the refrigerant and heats external air, and evaporates the refrigerant to the outside. An evaporator that cools the air to a temperature below the dew point; and a refrigerant path that connects the condenser and the evaporator, and has an intermediate pressure between the condensation pressure of the condenser and the evaporation pressure of the evaporator. Provided in a refrigerant path connecting the first heat exchanging means for evaporating the refrigerant to cool the external air and the condenser and the evaporator, and the condensation pressure of the condenser and the evaporation pressure of the evaporator A second heat exchange means for condensing the refrigerant at an intermediate pressure to heat the external air, the first heat exchange means, the evaporator, the second heat exchange means, the condenser, and the storage bin. And an air path that connects them in this order. It is a 燥貯 built apparatus.
[0010]
Furthermore, in another aspect of the present invention, the stored product is stored in the storage bin, the fluid is circulated through the heat transfer pipe installed in the storage bin, the pressure of the refrigerant is increased, and the refrigerant To heat the fluid inside the heat transfer tube, evaporate the refrigerant in the evaporator to cool the external air to a temperature below the dew point, and in the first heat exchange means, the condensation pressure of the condenser And the external air is cooled by evaporating the refrigerant at a pressure intermediate between the evaporation pressure of the evaporator and the evaporation pressure of the evaporator, and in the second heat exchange means, a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator The refrigerant is condensed in order to heat the external air, and the first heat exchange means, the evaporator, the second heat exchange means, and the storage bin are connected in this order by an air path, The external air heated in the heat exchange means of 2 Supplies to the serial storage bin, the internal fluid of the heat transfer tube heated in the condenser is supplied to the storage bin, a drying method of storage items, characterized in that drying the reservoir.
[0011]
In another aspect of the present invention, the stored item is stored in a storage bin, the pressure of the refrigerant is increased, the refrigerant is condensed in the condenser to heat the external air, and the refrigerant is evaporated in the evaporator. The external air is then cooled to a temperature below the dew point, and the first heat exchange means evaporates the refrigerant at a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator to cool the external air. In the second heat exchange means, the refrigerant is condensed at a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator to heat external air, and the first heat exchange means and the evaporator And the second heat exchanging means and the condenser are connected in this order by an air path, the external air heated in the condenser is supplied to the storage bottle, and the stored product is dried. It is a method for drying a stored product.
[0012]
According to the present invention, among the amount of heat for cooling the air, in the cooling step up to the dew point, heat is exchanged with the air after dehumidification, so that most of the amount of heat cooled by the evaporator can be used for the dehumidifying step. Therefore, the dehumidifying capacity per input of the compressor is increased.
[0013]
Moreover, since the high heat source of the heat pump is also used as a heating source in the middle of the drying process, the drying process does not become an isoenthalpy process and is close to an isothermal process. Therefore, since the increase in the relative humidity of the air during the drying process is small, the drying action is continued, so that the amount of air blow can be saved. Moreover, since the maximum temperature of air can be lowered with respect to the heating amount of the same amount of heat, the condensation temperature of the heat pump can be lowered. Accordingly, the compression ratio of the heat pump is lowered and the coefficient of operation (COP) is improved, so that the power cost can be saved.
[0014]
Furthermore, when the heat exchanging means is used as a precooling / preheating heat exchanger, the working medium of the heat exchanging means and the working medium of the heat pump are the same, and the refrigerant charging process can be shared, so the manufacturing cost of the heat exchanger, Maintenance is cheap. In addition, the precooling / preheating heat exchanger can be manufactured as one piece, and it does not require the internal wick of the heat pipe, and can be manufactured with a normal air / refrigerant heat exchanger coil production facility without an internal wick. The manufacturing cost is cheap.
[0015]
Further, due to the multi-economizer effect of the heat pump, the refrigerant enthalpy at the evaporator inlet is reduced and the refrigerant refrigeration effect per unit flow rate is high, so that the dehumidification effect and energy efficiency are increased.
[0016]
In a preferred aspect of the present invention, the first heat exchange means and the second heat exchange means are configured such that air flowing through the heat exchange means flows opposite to each other, and In the first heat exchange means and the second heat exchange means, the refrigerant path includes at least a pair of first and second penetration portions in a first plane substantially orthogonal to the air flow. And having at least a pair of a first penetrating portion and a second penetrating portion in a second plane substantially orthogonal to the air flow different from the first plane, and the first plane An intermediate stop is provided at a position that moves from the inside to the second plane.
[0017]
If comprised in this way, from the viewpoint of heat exchange between air, since it is counter flow heat exchange, high heat exchange efficiency can be achieved. The second surface has at least a pair of first and second penetrating portions in the first surface, forms a pair of refrigerant paths, and is substantially orthogonal to the flow of regeneration air different from the first surface. Since it has at least a pair of 1st penetration parts and a 2nd penetration part in a field and serves as a pair of refrigerant paths, a heat exchanger can be formed small and compact as a whole. In addition, since the intermediate diaphragm is provided at a position that moves from the first plane to the second plane, the evaporation or condensation pressure of the first and second through portions in the second plane is set to the first plane. Since it can be a value lower than the pressure of evaporation or condensation of the first and second penetrations in the inside, the heat exchange between the air flowing through each penetration can be close to the countercurrent heat exchange, Heat exchange efficiency can be increased. Note that the shapes of the first surface and the second surface are typically rectangular planes.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a first embodiment of a dry storage apparatus according to the present invention will be described in detail with reference to FIGS. 1 to 5. FIG. 1 is a diagram schematically illustrating a flow in a drying storage device according to the first embodiment of the present invention, and FIG. 2 is a diagram illustrating a configuration example of a dryer of the drying storage device in FIG. The dry storage device in the present embodiment cools the outside air below its dew point temperature and dehumidifies it, and heats the circulating water using a condenser, and includes a heat pump HP1 inside. The storage air is stored in a dry state by supplying outside air whose humidity has been lowered by the dry storage device and heated circulating water to the storage bottles, respectively.
[0019]
As shown in FIG. 1, the dry storage device includes a storage bin 101 for storing the stored item 100, and a dryer 102 that supplies dry air and hot water to the storage bin 101. As shown in FIGS. 1 and 2, the dryer 102 includes a blower 1 for introducing air OA from the outside, a refrigerant evaporator 2 that heats and evaporates the refrigerant, and an evaporator 2 that evaporates the gas. The booster 3 compresses the refrigerant, the refrigerant condenser 4 that cools and condenses the refrigerant, and the heat exchanger 5 that acts as an economizer. The heat exchanger 5 exchanges heat indirectly between the air before and after flowing into the evaporator 2 via a refrigerant, and cools the air by evaporating the refrigerant. 51 and a second heat exchange unit 52 that condenses the refrigerant and heats the air. These devices are accommodated in a cabinet 10, and the cabinet 10 is formed as a rectangular parallelepiped casing made of, for example, a thin steel plate.
[0020]
An air inlet 11 is opened at the uppermost front portion of the cabinet 10, and air OA from the outside is introduced into the dryer 102 through the air inlet 11. A filter 12 is provided in the vicinity of the air inlet 11 so that dust does not enter the apparatus from the outside. An air path through which air flows is formed in the cabinet 10 by a partition plate extending in the horizontal or vertical direction, and the air OA introduced from the intake port 11 passes through the uppermost air path 13a and is a middle air path. 13b, and flows from the middle air path 13b to the lowermost air path 13c. The air that has flowed into the lowermost air path 13 c is supplied to the storage bin 101 from a supply port 16 formed at the lowermost rear surface of the cabinet 10.
[0021]
In the middle air path 13b described above, the first heat exchanging part 51, the blower 1, and the evaporator 2 of the heat exchanger 5 are arranged in this order along the air flow direction. Here, the evaporator 2 cools the air introduced from the outside below its dew point temperature and recovers the moisture in the air as condensed water, and a drain pan 14 is installed below it. A drain tank 15 is disposed in the lowermost air path 13 c located below the drain pan 14, and moisture in the outside air OA condensed by the evaporator 2 is collected by the drain pan 14 into the drain tank 15. Accumulated. The drain pan 14 is preferably provided so as to cover not only the evaporator 2 but also the lower part of the heat exchanger 5. In the first heat exchanging part 51 of the heat exchanger 5, air is mainly precooled. However, since some moisture may condense here, it is particularly preferable to be provided below the first heat exchanging part 51. .
[0022]
In the lowermost air path 13c, the drain tank 15 and the second heat exchange part 52 of the heat exchanger 5 are arranged in this order along the air flow direction. Further, in the upper rear part of the cabinet 10, a room 13 d that houses a booster 3, a condenser 4, a water tank 17 that stores circulating water, and a pump 18 that pumps the circulating water from the water tank 17 to the condenser 4. Is formed. A flange 19 for connecting a pipe is provided on the rear surface of the room 13d.
[0023]
The storage bin 101 is provided with a floor mesh 103 in which a plurality of ventilation holes are formed. A stored material 100 is stored above the floor mesh 103, and a preheating chamber 104 is formed below the floor mesh 103. Further, a detoured heat transfer tube 105 is provided inside the storage bin 101. The heat transfer tube 105 is connected to the flange 19 of the dryer 102 described above, and hot water heated by the condenser 4 of the dryer 102 circulates inside the heat transfer tube 105. The heated hot water is supplied to the storage bin 101 via the heat transfer tube 105. In addition, although it is supposed that water will distribute | circulate inside the heat exchanger tube 105 of this embodiment, it is good also as distribute | circulating not only this but another fluid.
[0024]
As shown in FIG. 1, the refrigerant path through which the refrigerant flows in the dryer 102 includes a path 40 that connects the evaporator 2 and the booster 3, a path 41 that connects the booster 3 and the condenser 4, and condensation. It comprises a path 42 connecting the heat exchanger 4 and the heat exchanger 5 and a path 43 connecting the heat exchanger 5 and the evaporator 2. In the heat exchanger 5, the refrigerant path passes through the first heat exchange unit 51 and the second heat exchange unit 52, and the refrigerant is evaporated in the first heat exchange unit 51. The evaporation section 61 for cooling the air OA flowing through the first heat exchanging part 51 is formed by the air R, and the air R flowing through the second heat exchanging part 52 by condensing the refrigerant in the second heat exchanging part 52. Is formed. In addition, a throttle 48 is disposed in the refrigerant path 42 upstream of the first heat exchange unit 51 of the heat exchanger 5, and a throttle 49 is disposed in the refrigerant path 43 downstream of the second heat exchange unit 52. ing. As these restrictors 48 and 49, for example, an orifice, a capillary tube, an expansion valve, or the like can be used.
[0025]
FIG. 3 is an enlarged view showing a refrigerant path in the heat exchanger 5 of the dryer of FIG. The refrigerant path including the evaporation section 61 and the condensation section 62 passes through the first heat exchange unit 51 and the second heat exchange unit 52 alternately and repeatedly. That is, as shown in FIG. 3, the refrigerant path in the heat exchanger 5 is in order from the condenser 4 side in the order of the evaporation section 61a, the condensation section 62a, the condensation section 62b, the evaporation section 61b, the evaporation section 61c, and the condensation section 62c. , A condensing section 62d, an evaporating section 61d, an evaporating section 61e, and a condensing section 62e.
[0026]
Here, the first heat exchanging part 51 that flows the air OA before passing through the evaporator 2 and the second heat exchanging part 52 that flows the air R after passing through the evaporator 2 are separate rectangular parallelepiped spaces. Is housed in. In these rectangular parallelepiped spaces, a plurality of heat exchange tubes are arranged in parallel as refrigerant paths on a plane orthogonal to the air flow. In the first heat exchange unit 51 and the second heat exchange unit 52, a partition wall 510 and a partition wall 520 are provided adjacent to each other, and a heat exchange tube is provided through the two partition walls 510 and 520. It has been. As another form, the heat exchanger 5 divides one rectangular parallelepiped space into one partition, and a heat exchange tube passes through the partition to connect the first heat exchange unit and the second heat exchange unit. You may comprise so that it may penetrate alternately.
[0027]
The ends of the evaporation section 61b and the evaporation section 61c, and the ends of the evaporation section 61d and the evaporation section 61e are connected by a U tube 63, respectively. Similarly, the end portions of the condensing section 62a and the condensing section 62b and the end portions of the condensing section 62c and the condensing section 62d are also connected by the U tube 64, respectively. With such a configuration, the refrigerant that has flowed from the evaporation section 61 a toward the condensation section 62 a in the refrigerant path 42 is guided to the condensation section 62 b by the U tube 64. The refrigerant guided to the condensing section 62b further flows into the evaporating section 61b, is introduced into the evaporating section 61c by the U tube 63, and further flows into the condensing section 62c. Thus, the refrigerant path in the heat exchanger 5 is constituted by a meandering narrow tube group, and the narrow tube group passes through the first heat exchanging part 51 and the second heat exchanging part 52 while meandering, and has a high temperature. It comes into contact with air and air of low temperature alternately.
[0028]
Next, the flow of the refrigerant between the devices in the dryer 102 will be described with reference to FIGS. 1 and 2.
The refrigerant gas compressed by the booster 3 is guided to the condenser 4 via the refrigerant gas pipe 41 connected to the discharge port of the booster 3. In the condenser 4, the refrigerant gas compressed by the booster 3 is cooled and condensed by the circulating water supplied from the water tank 17 to the condenser 4 by the pump 18, and this circulating water is heated by this refrigerant.
[0029]
The refrigerant liquid exiting the condenser 4 is decompressed and expanded by the throttle 48, and a part of the refrigerant liquid is evaporated (flashed). The refrigerant in which the liquid and gas are mixed reaches the evaporation section 61a of the first heat exchange section 51, where the refrigerant liquid flows so as to wet the inner wall of the tube of the evaporation section 61a. The refrigerant liquid is heated and evaporated by the air OA introduced from the outside while flowing through the evaporation section 61a, and the air OA before flowing into the evaporator 2 is cooled (precooled). At this time, the refrigerant itself is heated to increase the gas phase.
[0030]
As described above, since the evaporating section 61a and the condensing section 62a are constituted by a series of tubes, the refrigerant gas evaporated in the evaporating section 61a (and the refrigerant liquid that has not evaporated) flows into the condensing section 62a. In the condensing section 62a, the air R cooled and dehumidified by the evaporator 2 is heated (reheated) at a temperature lower than the air in the evaporating section 61a. It flows into the next condensing section 62b. While the refrigerant flows through the condensing section 62b, the refrigerant is further deprived of heat by the low-temperature air R to condense the gas-phase refrigerant.
[0031]
The condensed refrigerant liquid flows into the next evaporation section 61b and the subsequent evaporation section 61c, and the air OA before flowing into the evaporator 2 is cooled (precooled) in the same manner as described above. Further, the refrigerant gas flows into the condensing section 62c and the condensing section 62d, and the air R is heated. Thus, the refrigerant flows through the refrigerant path in the heat exchanger while repeating the phase change between the gas phase and the liquid phase, and the air OA before being cooled by the evaporator 2 and the absolute humidity by being cooled by the evaporator 2. Heat exchange is indirectly performed with the lowered air R.
[0032]
The refrigerant liquid condensed in the final condensing section 62e is depressurized and expanded by the throttle 49 disposed on the downstream side of the second heat exchanging section 52, and the temperature decreases. Then, the refrigerant reaches the evaporator 2 and evaporates in the evaporator 2. The air Q that has passed through the first heat exchanging portion 51 is cooled by the heat of evaporation of the refrigerant. The refrigerant evaporated and gasified in the evaporator 2 is guided to the suction side of the booster 3. Then, the above cycle is repeated.
[0033]
Next, the effect | action of heat pump HP1 contained in the dry storage apparatus in this embodiment is demonstrated. 4 is a refrigerant Mollier diagram of the heat pump HP1 included in the dry storage device of FIG. In the diagram shown in FIG. 4, HFC134a is used as the refrigerant, and the horizontal axis represents enthalpy and the vertical axis represents pressure. Not only HFC134a but also HFC407C and HFC410A can be used as refrigerants, and when these refrigerants are used, the operating pressure region shifts to a higher pressure side than in the case of HFC134a.
[0034]
In FIG. 4, a point a indicates the state of the refrigerant evaporated in the evaporator 2 of FIG. 1, and the refrigerant at this time is in a saturated gas state. The pressure of the refrigerant is 0.30 MPa, the temperature is 1 ° C., and the enthalpy is 399.2 kJ / kg. Point b shows the state in which this gas is sucked and compressed by the booster 3, that is, the state at the discharge port of the booster 3, and the refrigerant at this time has a pressure of 1.89 MPa and is in a superheated gas state. .
[0035]
The refrigerant gas in the state of point b is cooled in the condenser 4 and reaches the state indicated by point c. The refrigerant at this time is in a saturated gas state, the pressure is 1.89 MPa, and the temperature is 65 ° C. The refrigerant is further cooled and condensed under this pressure to reach the state indicated by point d. The refrigerant at this time is in a saturated liquid state, and its pressure and temperature are the same as the pressure and temperature at point c. The enthalpy at this time is 295.8 kJ / kg.
[0036]
The refrigerant liquid is depressurized by the throttle 48 and flows into the evaporation section 61 a of the first heat exchange unit 51. The state at this time is indicated by a point e, in which a part of the liquid is evaporated and the liquid and the gas are mixed. The pressure at this time is an intermediate pressure between the condensing pressure of the condenser 4 and the evaporating pressure of the evaporator 2, and is a value between 0.30 MPa and 1.89 MPa in this embodiment.
[0037]
In the evaporating section 61a, the cooling liquid evaporates under the above intermediate pressure, and a state of a point f1 located between the saturated liquid line and the saturated gas line is obtained at the same pressure. In this state, a part of the liquid is evaporated, but a considerable amount of the refrigerant liquid remains. And the refrigerant | coolant of the state shown by the point f1 flows in into the condensation sections 62a and 62b. In the condensing sections 62a and 62b, the refrigerant is deprived of heat by the low-temperature air R flowing through the second heat exchanging section 52 and reaches the state of the point g1.
[0038]
The refrigerant in the state of point g1 flows into the evaporation sections 61b and 61c, where heat is taken away and the liquid phase is increased to reach the state of point f2, and further flows into the condensation sections 62c and 62d. In the condensing sections 62c and 62d, the refrigerant increases the liquid phase and reaches the state of the point g2. The point g2 is located on the saturated liquid line in the Mollier diagram. At this time, the temperature of the refrigerant is 15 ° C., and the enthalpy is 220.5 kJ / kg. Similarly, evaporation and condensation in the evaporation sections 61d and 61e and the condensation section 62e are repeated, but in the Mollier diagram of FIG. 4, the evaporation sections 61d and 61e and the condensation section 62e are omitted, and the condensation section 62d is throttled 49. Is shown as being connected.
[0039]
The refrigerant liquid in the state of the point g2 is depressurized to 0.30 MPa, which is a saturation pressure at a temperature of 15 ° C., by the throttle 49, and reaches the state indicated by the point h. The refrigerant in the state of the point h reaches the evaporator 2 as a mixture of refrigerant liquid and gas at 1 ° C., where heat is taken from the air Q and is evaporated to become a saturated gas shown in the point a. This saturated gas is again sucked into the booster 3, and the above-described cycle is repeated.
[0040]
Thus, in the heat exchanger 5, the refrigerant changes in the evaporation state such as from the point e to the point f1 or from the point g1 to the point f2 in the evaporation section 61, and from the point f1 to the point g1, in the condensation section 62. Or since the state of condensation is changed from point f2 to point g2 and evaporative heat transfer and condensation heat transfer are performed, the heat transfer rate is very high and the heat exchange efficiency is high.
[0041]
Here, when considering as the compression heat pump HP1 including the booster 3, the condenser 4, the throttles 48 and 49, and the evaporator 2, when the heat exchanger 5 according to the present invention is not provided, the point d in the condenser 4 is Since the refrigerant in the state is returned to the evaporator 2 through the throttle, the enthalpy difference usable in the evaporator 2 is only 399.2−295.8 = 103.4 kJ / kg. However, when the heat exchanger 5 according to the present invention is provided, 399.2-2205 = 178.7 kJ / kg, and the amount of gas circulating to the booster with respect to the same cooling load, and hence the required power, is 42. % (= 1-103.4 / 178.7) can also be reduced. That is, it is possible to have the same action as the subcool cycle. As described above, the dry storage device of the present invention has a dehumidifying effect and energy efficiency because the refrigerant enthalpy at the inlet of the evaporator 2 is reduced due to the economizer effect of the heat pump HP1 and the refrigerant refrigeration effect per unit flow rate is high. Get higher.
[0042]
FIG. 5 is a moist air diagram showing an air conditioning cycle in the dry storage apparatus of FIG. In FIG. 5, symbols P to T, OA, and EX correspond to the air states denoted by the respective symbols in FIG.
The air OA introduced from the outside passes through the uppermost air path 13a of FIG. 2 and is sent to the first heat exchanging portion 51 of the heat exchanger 5 (air P), and is generated by the refrigerant that evaporates in the evaporation section 61. It is cooled to a certain level and the dry bulb temperature is lowered while keeping the absolute humidity constant (air Q). Since this is preliminary cooling before the evaporator 2 cools to the dew point temperature or lower, it can be called precooling.
[0043]
In the evaporator 2, the air Q is cooled below its dew point temperature by the refrigerant evaporating at a low temperature, and the dry bulb temperature is lowered to 5 ° C. while reducing the absolute humidity to 5 g / kg DA while depriving moisture (air R ). Note that DA in the unit of absolute humidity indicates dry air.
[0044]
The air R (absolute humidity 5 g / kgDA, dry bulb temperature 5 ° C.) flows into the second heat exchange section 52 of the heat exchanger 5 and is heated to some extent by the refrigerant condensed in the condensing section 62. Raise the dry bulb temperature (to an intermediate temperature between 5 ° C. and 60 ° C.) while keeping constant (air S). This is preheating before being heated in the preheating chamber 104 in the storage bin 101 and can be called preheating.
[0045]
The hot water heated in the condenser 4 is sent to the preheating chamber 104 of the storage bottle 101 by the pump 18, but the air S exiting the second heat exchanging section 52 is heated in the preheating chamber 104 and has a constant absolute humidity. The dry bulb temperature is further raised to 60 ° C. (air T). The air T blows upward through the ventilation holes of the floor mesh 103, deprives the moisture contained in the stored item 100 in the storage bin 101, raises the absolute humidity, and is exhausted from the upper portion of the storage bin 101. (EX).
[0046]
Here, in the air-side cycle shown in the wet air diagram of FIG. 5, the amount of heat ΔQ that heats the air S in the preheating chamber 104 is heating by using exhaust heat, and the amount of heat that cools the air Q in the evaporator 2. Δi is a dehumidifying cooling effect, and heat recovery by a heat exchanger as an economizer is ΔH.
[0047]
As described above, in the heat exchanger 5, the air OA introduced from the outside by the evaporation of the refrigerant in the evaporation section 61 is pre-cooled, and the air R is heated by the condensation of the refrigerant in the condensing section 62. The refrigerant evaporated in the evaporation section 61 is condensed in the condensation section 62. Thus, heat exchange between the air before and after being cooled by the evaporator 2 is indirectly performed by the evaporation and condensation action of the same refrigerant.
[0048]
As described above, in the dry storage device according to the present invention, the heat exchanger 5 is used as a precooling / preheating heat exchanger, the working fluid of the heat exchanger 5 and the working fluid of the heat pump HP1 are the same, and the refrigerant charge Manufacturing process and maintenance cost are low. In addition, the precooling / preheating heat exchanger can be manufactured as one body, and the internal wick of the heat pipe is not required, and it can be manufactured with the normal air / refrigerant heat exchanger coil production facility without the wick inside. Therefore, the manufacturing cost is low.
[0049]
Furthermore, since the pre-cooling of the air and the heating of the air after dehumidification are performed using the internal working medium using the heat pump HP1, the apparatus is simple, and most of the cooling capacity of the heat pump is reduced to the moisture in the air. Since it can be used for condensation, it has a high dehumidifying capacity.
[0050]
When the air is cooled and dehumidified, if the air is cooled to the dew point as it is, the amount of cooling is large. Therefore, a considerable portion of the cooling effect of the heat pump is consumed, and the dehumidifying capacity (dehumidifying performance) per compressor input is low. Therefore, an air / air heat exchanger 5 is provided before and after the evaporator 2 to perform precooling and reheating (preheating) of the air to reduce the sensible heat ratio and reduce the cooling amount to the dew point.
[0051]
Next, a second embodiment of the dry storage apparatus according to the present invention will be described in detail with reference to FIGS. FIG. 6 is a diagram schematically showing a flow in the dry storage device according to the second embodiment, and FIG. 7 is a refrigerant Mollier diagram of the heat pump HP2 included in the dry storage device of FIG. In addition, the same code | symbol is attached | subjected to the member or element which has the same effect | action or function as the member or element in the above-mentioned 1st Embodiment, and the part which is not demonstrated in particular is the same as that of 1st Embodiment.
[0052]
In the heat exchanger 150 in the dryer 202 according to the present embodiment, intermediate throttles 163 and 164 are provided between the condensation sections 162a and 162b and between the condensation sections 162c and 162d of the second heat exchange unit 152, respectively. This is different from the first embodiment described above. Other configurations are the same as those in the first embodiment. Such an intermediate throttle can also be provided on the evaporation section side of the first heat exchanger 151.
[0053]
In FIG. 7, points a to e are the same as those in the first embodiment shown in FIG. Note that the refrigerant in the state of the point e flowing into the evaporation section 161a of the heat exchanger 150 is in a state where a part of the liquid is evaporated and the liquid and the gas are mixed as described with reference to FIG.
[0054]
The refrigerant evaporates in the evaporating section 161a and reaches a state indicated by a point f1 that approaches the saturated gas line in the wet region on the Mollier diagram of FIG. The refrigerant in this state enters the condensing section 162a, where it is condensed and reaches the state indicated by the point g1a. The refrigerant in the state at the point g1a is depressurized through the intermediate throttle 163 and reaches the state indicated by the point g1b. That is, the refrigerant flows from the condensing section 162a through the restrictor 163 into the condensing section 162b.
[0055]
The refrigerant flowing into the condensing section 162b is condensed here, and reaches a state indicated by a point h1 that is in the wet region but close to the saturated liquid line. Thereafter, it enters the evaporation section 161b and is condensed here, and is inverted by the U tube and enters the evaporation section 161c where it is further condensed and reaches a state indicated by a point f2.
[0056]
Thereafter, the refrigerant passes through the condensing section 162c, the intermediate throttle 164, and the condensing section 162d, and reaches the state indicated by the points g2a, g2b, and h2, and further passes through the evaporation sections 161d and 161e and the condensing section 162e. Thus, the state indicated by the points f3 and h3 is reached. This point h3 is on the saturated liquid line in the Mollier diagram, the temperature is 11 ° C., and the enthalpy is 215.0 kJ / kg.
[0057]
Similarly to the case of the first embodiment, the refrigerant liquid at the point h3 is depressurized to 0.30 MPa, which is a saturation pressure at a temperature of 1 ° C., by the restrictor 49, becomes a point i state, and the refrigerant liquid and gas at 1 ° C. To the evaporator 2 where heat is taken from the air Q and evaporated to become a saturated gas in a state indicated by a point a on the Mollier diagram. This saturated gas is again sucked into the booster 3, and the above-described cycle is repeated.
[0058]
Here, when considering as the compression heat pump HP2 including the booster 3, the condenser 4, the throttles 48, 49, 163, 164 and the evaporator 2, the condenser 4 is provided when the heat exchanger 150 according to the present invention is not provided. Since the refrigerant in the state of the point d is returned to the evaporator 2 through the throttle, the enthalpy difference usable in the evaporator 2 is only 399.2−295.8 = 103.4 kJ / kg. However, when the heat exchanger 150 according to the present invention is provided, 399.2-215.0 = 184.2 kJ / kg, and the amount of gas circulated to the booster for the same cooling load, and thus the required power Can be reduced by 44% (= 1-103.4 / 184.2). That is, it is possible to have the same action as the subcool cycle.
[0059]
FIG. 8 shows an example of the structure of the heat exchanger 150 in the present embodiment. 8A is a front view seen in the air flow direction, FIG. 8B is a side view seen from a direction perpendicular to the air flow, and FIG. 8A is A in FIG. 8B. FIG. In FIG. 8A, the air OA flows forward from the front side of the page, and the air R flows from the front side to the front side. The tubes in the heat exchanger 150 are each arranged in 8 rows in four planes orthogonal to the air flow. That is, they are arranged in 4 rows and 8 columns along the air flow. In FIG. 1 and FIG. 6, for convenience, the heat exchange tubes have been described as having one row and one column, but typically, each row includes a plurality of tube columns. Moreover, such a heat exchanger may be arranged in parallel with respect to those flows according to the flow rate of air, or may be arranged in series.
[0060]
Such a heat exchanger is inexpensive and economical when used in place of an expensive heat pipe. Also, unlike the heat pipe, the working fluid can be the same as that of the heat pump, so that maintenance is not required.
[0061]
Although one embodiment of the present invention has been described so far, the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea. For example, the number of evaporation sections in the first heat exchange section and the number of condensation sections in the second heat exchange section of each refrigerant path are not limited to those shown in the figure.
[0062]
In the above embodiment, the circulating water is heated by the condenser 4 and supplied to the storage bottle 101. However, the air heated in the second heat exchange unit is directly heated by the condenser, This may be supplied to the storage bin 101 to dry the stored item 100 in the storage bin 101. FIG. 9 shows a configuration in the case where the air heated by the second heat exchange unit 52 is heated by the condenser 4 and supplied to the storage bottle 101 in the dry storage device of the first embodiment described above. An example is shown. In the case of the dryer 302, the above-described dryer flange (indicated by reference numeral 19 in FIGS. 1 and 6), pump (indicated by reference numeral 18 in FIGS. 1 and 6), heat transfer tube (in FIGS. 1 and 6). Is indicated by 104).
[0063]
【The invention's effect】
As described above, according to the present invention, air can be pre-cooled by the first heat exchanging means before cooling in the evaporator, and the pre-cooling heat can be recovered from the air once cooled in the evaporator. It is possible to provide a dry storage device equipped with a heat pump with a high operating coefficient. Moreover, it can be set as the dry storage apparatus with high dehumidification capability per energy consumption.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing a flow in a dry storage apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration example of a dryer of the drying storage device of FIG. 1;
3 is an enlarged view showing a refrigerant path in the heat exchanger of the dry storage device of FIG. 1. FIG.
FIG. 4 is a refrigerant Mollier diagram of a heat pump included in the dry storage device of FIG.
FIG. 5 is a wet air diagram in the dry storage device of FIG. 1;
FIG. 6 is a diagram schematically showing a flow in a dry storage apparatus according to a second embodiment of the present invention.
7 is a refrigerant Mollier diagram of a heat pump included in the dry storage device of FIG. 6. FIG.
8 is a diagram showing an example of the structure of a heat exchanger of the dry storage device of FIG. 6. FIG.
FIG. 9 is a diagram schematically showing a flow in a dry storage apparatus according to another embodiment of the present invention.
FIG. 10 is a diagram schematically showing a flow in a conventional dry storage apparatus.
FIG. 11 is a diagram of moist air in a conventional dry storage device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Blower 2 Evaporator 3 Booster 4 Condenser 5, 150 Heat exchanger 10 Cabinet 11 Inlet 12 Filter 13a, 13b, 13c Air path 14 Drain pan 15 Drain tank 16 Supply port 17 Water tank 18 Pump 19 Flange 51 First Heat exchanger 52 Second heat exchanger 61 Evaporating section 62 Condensing section 63, 64 U tubes 40-43 Paths 48, 49, 163, 164 Restriction 100 Storage 101 Storage bins 102, 202 Dryer 103 Floor mesh 104 Preheating chamber 105 Heat transfer tube

Claims (5)

A storage bin in which stored items are stored;
A heat transfer tube installed in the storage bin and through which a fluid flows;
A booster for boosting the refrigerant;
A condenser for condensing the refrigerant and heating the fluid inside the heat transfer tube;
An evaporator that evaporates the refrigerant and cools external air to a temperature below the dew point;
Provided in a refrigerant path connecting the condenser and the evaporator, and evaporates the refrigerant at a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator to cool external air. Heat exchange means;
Provided in a refrigerant path connecting the condenser and the evaporator, and heats the external air by condensing the refrigerant with a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator. Heat exchange means;
A drying storage device comprising: an air path connecting the first heat exchange means, the evaporator, the second heat exchange means, and the storage bin in this order. A storage bin in which stored items are stored;
A booster for boosting the refrigerant;
A condenser that condenses the refrigerant and heats external air;
An evaporator that evaporates the refrigerant and cools external air to a temperature below the dew point;
Provided in a refrigerant path connecting the condenser and the evaporator, and evaporates the refrigerant at a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator to cool external air. Heat exchange means;
Provided in a refrigerant path connecting the condenser and the evaporator, and heats the external air by condensing the refrigerant with a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator. Heat exchange means;
A dry storage apparatus comprising: an air path connecting the first heat exchange means, the evaporator, the second heat exchange means, the condenser, and the storage bin in this order. The first heat exchanging means and the second heat exchanging means are configured such that air flowing through the heat exchanging means flows opposite to each other.
In the first heat exchange means and the second heat exchange means, the refrigerant path has at least a pair of first and second through portions in a first plane substantially orthogonal to the air flow. And having at least a pair of a first penetrating portion and a second penetrating portion in a second surface substantially orthogonal to the air flow different from the first surface,
The dry storage apparatus according to claim 1 or 2, further comprising an intermediate diaphragm at a position that moves from the first plane to the second plane. While storing a store thing in the inside of a storage bottle, circulating a fluid through the inside of a heat exchanger tube installed in the storage bottle,
Pressurize the refrigerant,
In the condenser, the refrigerant is condensed to heat the fluid inside the heat transfer tube,
In the evaporator, the refrigerant is evaporated to cool the external air to a temperature below the dew point,
In the first heat exchange means, the refrigerant is evaporated at a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator to cool the external air,
In the second heat exchange means, the refrigerant is condensed at a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator to heat the external air,
The first heat exchange means, the evaporator, the second heat exchange means and the storage bin are connected in this order by an air path,
The external air heated in the second heat exchanging means is supplied to the storage bin, and the fluid inside the heat transfer tube heated in the condenser is supplied to the storage bin to dry the stored product. A method for drying a stored product. Store the store in the storage bin,
Pressurize the refrigerant,
In the condenser, the refrigerant is condensed to heat external air,
In the evaporator, the refrigerant is evaporated to cool the external air to a temperature below the dew point,
In the first heat exchange means, the refrigerant is evaporated at a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator to cool the external air,
In the second heat exchange means, the refrigerant is condensed at a pressure intermediate between the condensation pressure of the condenser and the evaporation pressure of the evaporator to heat the external air,
The first heat exchange means, the evaporator, the second heat exchange means and the condenser are connected in this order by an air path,
A method for drying a stored product, comprising supplying external air heated in the condenser to the storage bottle and drying the stored product.

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