JPH0621723B2 - Heat pump device for dehumidifying and drying air - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is for treating substances that must be observed at low temperatures, such as foods, pharmaceuticals, granular agents, sludge and the like. The present invention relates to a heat pump device for dehumidifying and drying air.

(Prior Art) Conventionally, substances that must be dried at a low temperature, for example, dehumidification in drying foods, pharmaceuticals, granular materials, sludge, etc.
Generally, a solution such as lithium chloride or ethylene glycol is sprayed to exchange heat with air to make dehumidified air, but the solution that has absorbed and diluted is heated by a concentrator, concentrated, and then cooled by air cooling. . Further, a refrigerator provided separately is used for the pre-cooling chamber of the dried object.

(Problems to be Solved by the Invention) In the prior art, fan power, pump power, etc. by a cooling tower and an extra concentrating device for heating and concentrating are required. Also, since the solution mixes with the circulating air and scatters, the solution must be constantly replenished, the solution is a consumable item, and the heat required for heating and concentrating is 80% from the boiler efficiency. The thermal efficiency is as follows. Therefore, the maintenance of the device is very troublesome and economically burdensome. In addition, there is a drawback that thulium chloride, ethylene glycol, etc. mixed in the air adheres to the material to be dried, and there is also a bad effect of rotting. In addition, since a boiler must be provided for heating and a refrigerator must be provided for cooling, there is a problem in terms of energy saving, and there are drawbacks such as increased equipment cost. The present invention is intended to solve these drawbacks, and does not use lithium chloride or ethylene glycol for dehumidification, adopts a refrigeration dehumidification method, and creates low temperature dehumidified dry air to blow or circulate. In addition, the present invention aims to achieve energy saving and eliminate the drawbacks of the prior art by simultaneously performing heating using a heat pump.

[Structure of Invention]

(Means for Solving Problems) As means for solving the above problems, the heat pump device of the present invention is a drying chamber with dry air, an air chamber for producing dry air, and heating and cooling means in the air chamber. As a primary and secondary reverse Carnot cycle means, the drying chamber and the air chamber are connected by a circuit for introducing dry air and a circuit for refluxing the absorbed air,
In the air chamber, a heat exchanger for heat absorption and a heat exchanger for heat generation of the secondary reverse Carnot cycle are provided at positions closest to the air inlet side and the air outlet side of the air chamber, respectively. A Carnot cycle heat absorption heat exchanger and a heat generation heat exchanger are provided inside the secondary reverse Carnot cycle heat absorption heat exchanger and heat generation heat exchanger, respectively.

Further, a circuit for forming a third reverse Carnot cycle using heat obtained from the radiator of the reverse Carnot cycle as a heat absorption source and introducing the absorbed heat to the final side of the drying chamber is provided.

(Operation) In the air chamber, the absorbed circulating air or the outside air is first cooled and dehumidified by using two sets of heat pump devices,
Next, this is heated using the heat pump device, adjusted to an appropriate temperature, and introduced into a drying chamber.

By placing the heat exchanger for heat absorption and the heat exchanger for heat generation of the secondary reverse Carnot cycle and the primary reverse Carnot cycle in mutually specific arrangements, the compression ratio of both cycles can be made small and the coefficient of performance of heating and cooling can be reduced. Together with each other.

Further, if necessary, a third-order reverse Carnot cycle using the heat obtained from the reverse Carnot cycle as an endothermic source is operated to efficiently obtain hot air at a higher temperature.

(Embodiment) One embodiment of the present invention will be described with reference to FIG. 1. This embodiment can be used in combination with a so-called "air circulation closed cycle system" and "outside air (fresh air) intake type open cycle system".

Reference numeral 1 denotes a drying chamber in which a material 6 to be dried, such as food, medicine, powdery or granular material, and sludge, is introduced into a precooling chamber 2 of the drying chamber 1 by a conveyor and made into uniform particles by a uniform crusher 3. It is then supplied onto the net conveyor 4, dried while moving in the drying chamber 1, and discharged as a finished product 7 such as food, medicine, powdery or granular material, sludge and the like. Upper and lower partition plates 1 in the drying chamber 1
It is divided into a large number of divisions 16 by 4 and 15, and air flows vertically in each division 16.

The introduction of dry air in the drying chamber 1 is performed as follows. First, the cool air of 5 to 7 ° C. is blown by the blower 9 into the inflow pipes 11a and 11b.
Through the precooling front chamber 2. 30-40 ° C / 6g /
The low-temperature dry air of kg is fractionated by the blower 8 through the inflow pipes 13a and 13b into 23 divisions 16 to be dried, and further the inflow pipes
After dividing from 13c to 3 other divisions 16 and drying,
It flows out from the reflux pipe 13d, is dust-removed by the filter 70, and is a blower 8a.
Circulating air duct 18 again from air chamber 17
Is flowed into.

Next, the air chamber 17 will be explained. In the air chamber 17, in the direction of air flow, a precooler 21, a first cooler 22, a second cooler 23, an eliminator 24, an intermediate heater 54,
A reheater 25 and a hot water heater 26 are provided respectively.
Circulating air duct 18 to air chamber 17 at 35 ° C / 1
The pre-cooler 21 19
It is pre-cooled to ℃, cooled to 15.5 ℃ in the first cooler 22 to condense water, then cooled to 6.5 ℃ in the second cooler 23, further condensed to remove water in the eliminator 24. . 28 is a drain trap. Next, the dehumidified air is heated in the intermediate heater 54 and the reheater 25 and then further heated by the hot water heater 26 to 40-50.
It becomes dry air of ℃ / 6g / kg. This dry air is inflow pipe
It is again introduced into the drying chamber 1 through 13a and 13b.

Next, transfer of heat from or to the air flowing through the air chamber 17 will be described.

The precooler 21 and the reheater 25 are formed in a closed cycle so that a coolant liquid (ethylene glycol, brine, etc.) is circulated by the pump 30, and the coolant in the reheater 25 is cooled to about 11.5 by the cool air of 6.5 ° C. After being cooled to ℃, it flows into the pre-cooler 21 by the pump 30, pre-cools the 35 ℃ absorbed air and becomes a refrigerant liquid of about 30 ℃ and returns to the reheater 25, and the 6.5 ℃ air is passed through the intermediate heater 54 to about Raise the temperature to 25 ° C.

H is a secondary reverse Carnot cycle on the high-stage side, that is, a heat pump cycle, in which the refrigerant is compressed by the compressor 31 and condensed by the hot water heater (condenser) 32, and the liquid refrigerant passes through the liquid pipe 62 and radiates heat as an intercooler. The liquid refrigerant that has flowed into the condenser (condenser) 35 and has passed through the liquid pipe 64 flows into the first cooler 22 through the main expansion valve 33 and evaporates, and the air at 19 ° C. that has flowed out by the pre-cooter 21 is After cooling to 0.5 ° C., it is sucked into the compressor 31 again. R is a low-stage primary reverse Carnot cycle, that is, a refrigeration cycle, and the refrigerant compressed by the compressor 34 is introduced from the gas pipe 60 to the intermediate heater 54 through the three-way valve 47c and the second cooler 23.
From the first cooler 22 through the gas pipe 61, the vapor pressure adjusting valve 37, and the evaporator 35 through the gas pipe 53. At the same time, it is sucked into the compressor 31. The liquid refrigerant flowing from the gas pipe 53 into the radiator 35 merges with the refrigerant in the liquid pipe 62 via the valve 49. The liquid refrigerant branched from the liquid pipe 64 flows into the heat exchanger 30 via the liquid pipe 52 and is cooled, then flows into the second cooler 23 via the expansion valve 36, evaporates, and flows out from the first cooler 22.
The 5.5 ° C air is further cooled to 6.5 ° C. The evaporated refrigerant flows into the heat exchanger 30 via the evaporation pressure adjusting valve 38,
After the cold heat is applied, it is sucked into the compressor 34 again.

The evaporation temperature of the first cooler 22 on the intake side of the absorbed air is around 10 ° C., and the evaporation temperature of the second cooler 23 is from 0 ° C. to slightly higher. This is because frost adheres to the fin coil of the heat exchanger at 0 ° C. or lower, which is an adverse effect.

The heating of the air at the outlet of the air chamber 17 is performed as follows. Heat pump cycle H hot water heater 32
The warm water heated to about 42 ° C. ± 2 ° C. flows into the warm water heater 26 through the warm water pipe 45 and the warm water pipe 45a by the circulation pump 46. 47 is a hot water supply electric three-way valve that adjusts the flow rate of hot water. The hot water radiated by the hot water heater 26 returns to the hot water heater 32 via the return pipes 44, 44a. The hot water branched from the hot water supply electric three-way valve 47 releases excess heat of the heat pump to the outside of the system by the radiator 48, and adjusts the blowing temperature of the dry air at an appropriate temperature.

The above embodiment is a system in which the air circulates in the drying chamber 1 and the air chamber 17 in a closed cycle. However, when the humidity of the outside air is lower than the humidity of the hygroscopic air discharged from the drying chamber 1, the outside air is freshened by the blower 8a. From the air intake 50, the air is sucked directly into the air chamber 17, and the absorbed air is discharged from the absorbed air outlet 51.
It is also possible to adopt an open air intake type open cycle method. However, in general, when taking in outside air and repeating discharge,
It is necessary to be careful because dust is likely to be mixed in and there is a harmful effect of oxidizing the article.

Further, depending on the type of material to be dried or the drying conditions, it becomes necessary to supply hot air having a higher temperature, for example, about 70 ° C. to the drying chamber 1. For such a case, a third-order inverse Carnot cycle M is provided. The refrigerant flowing in the refrigerant evaporator 94 is heated by the heat (2) obtained in the radiator (condenser) 35.
0 ° C to 30 ° C) is absorbed and compressed by the compressor 81, liquefied in the refrigerant condenser 83, and the air flowing through the air heater 82 is heated to obtain hot air at about 70 ° C. This hot air is
The air blower 90 flows into the final side 93 of the drying chamber 1 through the inflow pipe 91 to add and dry the material to be dried, and then flows out to the reflux pipe 92 and returns to the air heater 82 again.

The heating tower 87 for absorbing heat from the air heat source is for replenishing the shortage with respect to the outside air when the heat absorption source has a shortage. Reference numeral 88 is a refrigerant evaporator, and 85 and 89 are expansion valves.

FIG. 2 is a second embodiment in which the embodiment of FIG. 1 is partially modified. In the first embodiment, the high-pressure refrigerant discharged from the compressor 31 of the heat pump cycle H flows back from the hot water heater 26 at the outlet of the air chamber 17 through the reflux pipe 44a (the temperature is lowered). Although it is configured to condense in the warm water heater (condenser) 32 that is cooled by the above, in the second embodiment, the high pressure refrigerant is
In the point that the refrigerant condenser 26a is configured to be directly cooled and condensed through the gas pipes 45 and 45a,
Although it is different from the embodiment described above, the other configurations are the same, and the description thereof will be omitted.

FIG. 3 shows a third embodiment in which the first embodiment (FIG. 1) is partially modified. The same reference numerals as those in FIG. 1 are the portions having the same names and the same structures, and the functions thereof are also the same, so that the description thereof is omitted. This embodiment is different from the first embodiment in that a radiator (condenser) 35 as an intercooler is additionally provided with means for auxiliary cooling by outside air or well water. That is, the radiator 35 is connected to the outside air radiator (cooling tower) 41 via the cooling water pipes 39 and 40 and the pump 42, and the well water 56 is the pump 55 and the well water inflow pipe 57.
The cooling water pipe 40 and the well water outflow pipe 58 are connected to the cooling water pipe 39 via the pipes, respectively, so that either the outside air or the well water can be switched. Therefore,
When the intermediate heater 54 is not used, the three-way valve 47c is switched to allow the refrigerant discharged from the compressor 34 to directly flow into the radiator 35 as an intermediate cooler, and to cool the outside air radiator 41 or the well water 56. Can be driven to cool it.
Further, in this embodiment, by appropriately adjusting the valves of the liquid pipes 62 and 65, a part of the refrigerant liquid condensed in the hot water heater 32 passes through the liquid pipes 65 and 66 without flowing into the radiator 35. First
Also different from the first embodiment in that only the other part of the refrigerant liquid can flow into the second cooler 23 through the liquid pipe 62, the radiator 35, and the liquid pipes 67 and 63. There is.

The third-order reverse Carnot cycle system that operates when hot air of high temperature is required is exactly the same as that of FIG.

FIG. 4 shows a fourth embodiment in which the third embodiment is partially modified. In this embodiment, the heat pump cycle H on the high stage side and the refrigeration cycle R on the low stage side are completely separated from each other in the flow of the refrigerant, and the radiator 35a.
The intermediate heater 54 is different from the third embodiment in that the intermediate heater 54 is incorporated into the system in parallel in the refrigeration cycle R. According to this embodiment, different refrigerants can be used in the heat pump cycle H and the refrigeration cycle R, respectively. The other structure is the same as that of the third embodiment.

The third-order reverse Carnot cycle system, which operates when high-temperature hot air is required, has exactly the same configuration as that of Fig. 1, but in this case, it works as the higher-stage cycle of the primary reverse Carnot cycle, and the heat pump cycle It functions as.

〔The invention's effect〕

The present invention adopts a refrigerating dehumidification method without using thylium chloride, ethylene glycol, etc. for dehumidification, creates low-temperature dry air and blows or circulates it, and improves dehumidification efficiency by a heat pump to measure energy saving efficiency. At the same time, the raw material can be cooled when a refrigerator for cold air drying is used. Then, the humidified circulating air or the outside air is cooled by using a heat pump to dehumidify it, and further the air is heated in the drying chamber up to the outlet condition by heating by the heat pump, and the relative humidity can be lowered to achieve energy-saving drying.

Further, when the condition of the material to be dried is required, the air for drying can be efficiently raised to a higher temperature by using a separate heat pump.

[Brief description of drawings]

1 to 4 are system diagrams of different embodiments of the present invention. 1 ... Drying chamber, 13a, 13b, 13c ... Inflow pipe as a circuit for introducing dry air from the air chamber into the drying chamber, 13
d ...... Recirculation pipe as a circuit for returning the absorbed air from the drying chamber to the air chamber, 17 ...... Air chamber, 18 ......
Circulating air duct as a circuit for returning the absorbed air from the drying chamber to the air chamber, 22 ... the first cooler as an endothermic heat exchanger, 23 ... the second cooler as an endothermic heat exchanger, 26. Water heaters as heat exchangers for water, 31, 34
...... Compressor, 35, 35a …… Radiator, 54 …… Intermediate heater as heat exchanger for heat generation 81 …… Compressor, 91 …… Introduces heat obtained from the radiator to the final side of the drying chamber Inflow pipe as a circuit to do. R: primary reverse Carnot cycle, H: secondary reverse Carnot cycle, M: tertiary reverse Carnot cycle.

Claims (14)

[Claims] 1. A drying chamber with dry air, an air chamber for producing dry air, a circuit for introducing the dry air from the air chamber into the drying chamber, and a circuit for returning hygroscopic air from the drying chamber to the air chamber, a primary And a secondary reverse Carnot cycle, comprising a heat exchanger for heat absorption and heat exchanger for heat generation of the reverse Carnot cycle in the air chamber, the heat exchanger for heat absorption of the secondary reverse Carnot cycle of the air chamber The heat exchanger for heat generation of the secondary reverse Carnot cycle is installed closest to the air inlet side, and the heat exchanger for heat absorption and heat generation for heat generation of the primary reverse Carnot cycle are installed closest to the air outlet side of the air chamber. An exchanger is installed inside each of the heat exchanger for heat absorption and the heat exchanger for heat generation corresponding to the secondary reverse Carnot cycle, and further,
An air characterized by forming a third reverse Carnot cycle using the heat obtained from the radiator of the reverse Carnot cycle as an endothermic source, and introducing the absorbed heat to the final side of the drying chamber. Heat pump device for dehumidifying and drying. 2. The heat pump device for air dehumidifying and drying according to claim 1, wherein the heat exchanger for heat generation of the secondary reverse Carnot cycle is a hot water heater. 3. The heat pump apparatus for dehumidifying and drying air according to claim 1, wherein the heat exchanger for heat generation of the secondary reverse Carnot cycle is a refrigerant condenser. 4. The air according to any one of claims 1 to 3, wherein the heat exchanger for heat absorption of the primary reverse Carnot cycle and the secondary reverse Carnot cycle is a refrigerant evaporator. Heat pump device for dehumidifying and drying. 5. The heat exchanger for heat generation of the primary reverse Carnot cycle is an intermediate heater that utilizes the heat of the refrigerant gas discharged from the compressor, as claimed in any one of claims 1 to 4. A heat pump device for dehumidifying and drying air according to any one of claims. 6. A two-stage or two-stage compressor comprising a secondary reverse Carnot cycle as a high-stage side cycle and a primary reverse Carnot cycle as a low-stage side cycle in a two-stage or dual compressor. A heat pump device for dehumidifying and drying air according to any one of items 5. 7. A radiator as an intercooler is provided between an intermediate heater of a primary reverse Carnot cycle and a suction side of a compressor of a secondary reverse Carnot cycle. A heat pump device for dehumidifying and drying air according to any one of items 1 to 5. 8. A third reverse Carnot cycle refrigerant evaporator is provided in a radiator as an intermediate cooler provided between a primary reverse Carnot cycle intermediate heater and a secondary reverse Carnot cycle compressor suction side. The dehumidifying and drying air according to any one of claims 1 to 7, wherein a circuit for circulating air is provided between the refrigerant condenser of the tertiary reverse Carnot cycle and the final side of the drying chamber. Heat pump equipment. 9. An intermediate heater and a radiator are provided in parallel between the compressor of the primary reverse Carnot cycle and the evaporator, and the first, second, or fourth claim. A heat pump device for dehumidifying and drying air according to any one of items 5. 10. A refrigerant evaporator of a tertiary reverse Carnot cycle is provided in a radiator provided between a compressor and an evaporator of the primary reverse Carnot cycle, and a refrigerant condenser of the tertiary reverse Carnot cycle and a final drying chamber are provided. Claims 1, 2, 4 and 5 in which a circuit for circulating air is provided between the first and second sides.
Item 10. A heat pump device for dehumidifying and drying air according to item 9 or 10. 11. A heat exchanger is provided on each of an air inlet side and an air outlet side of an air chamber to form a closed circulation path through which a heat medium flows, thereby forming a closed circulation path. A heat pump device for dehumidifying and drying air according to any one of 1. 12. A circuit for recirculating the absorbed air from the drying chamber to the air chamber is provided with an outside air introduction port and a absorbed air discharge port, as claimed in any one of claims 1 to 11.
Item 10. A heat pump device for dehumidifying and drying air according to any one of items. 13. The cooling air on the outlet side of the heat exchanger for heat absorption of the primary reverse Carnot cycle in the air chamber is introduced into the front chamber or the precooling chamber of the drying chamber. Item 13. A heat pump device for air dehumidifying and drying according to any one of items 12 to 12. 14. A refrigerant for a primary reverse Carnot cycle is R12.
Or R22 as the refrigerant of the secondary reverse Carnot cycle
14. The heat pump device for dehumidifying and drying air according to claim 9, wherein the heat pump device is 14.