JP2002372332A - Adsorptive heat pump, and adsorption member for the adsorptive heat pump, and air conditioning apparatus for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high efficiency adsorptive heat pump using an adsorption member where an adsorptive substance is adsorbed and desorbed in a low relative vapor pressure region. SOLUTION: In an absorptive heat pump comprising an adsorbate, an adsorption/desorption section including an adsorption member for absorbing and desorbing the adsorbate, and a vaporization/condensation section for vaporizing/condensing the adsorbate coupled with the adsorption/desorption section, the adsorption member is zeolite involving aluminum, phosphorus, and a hetero atom as a skeleton.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adsorption heat pump using a specific adsorbent, an operation method thereof, and a vehicle air conditioner using the adsorption heat pump. Further, the present invention relates to an adsorbent for an adsorption heat pump.

[0002]

2. Description of the Related Art In an adsorption heat pump, an adsorbate,
For example, in order to regenerate an adsorbent that has absorbed water, the adsorbent is heated to desorb the adsorbate, the dried adsorbent is cooled to the temperature used for adsorbate adsorption, and used again for adsorbate adsorption. . Waste heat and heat of relatively high temperature (120 ° C or higher)
Absorption heat pumps that are used as regeneration heat sources for adsorbents have already been put to practical use. However, since the heat obtained by cooling water or solar heat of cogeneration equipment, fuel cells, and automobile engines is relatively low at 100 ° C. or less, it cannot be used as a driving heat source for absorption heat pumps currently in practical use. , 100 ° C or less, and 60
There has been a demand for effective utilization of low-temperature exhaust heat at a temperature of from 80C to 80C.

[0003] Even if the operation principle of the adsorption heat pump is the same, the adsorption characteristics required for the adsorbent greatly differ depending on the available heat source temperature. For example, the exhaust heat temperature of a gas engine cogeneration or a polymer electrolyte fuel cell used as a heat source on the high temperature side is 60 ° C to 80 ° C, and the temperature of cooling water for an automobile engine is 85 ° C to 90 ° C. The temperature of the heat source on the cooling side also differs depending on the installation location of the device. For example, in the case of a car, the temperature is obtained by a radiator, and in a building or a house, the temperature is a temperature of a water cooling tower or river water. That is, the operating temperature range of the adsorption heat pump is 25 ° C. to 35 ° C. on the low temperature side and 6 ° C. on the high temperature side when installed in a building or the like.
0 ° C. to 80 ° C., when installed in an automobile or the like, the low temperature side is about 30 ° C. to 40 ° C., and the high temperature side is about 85 ° C. to 90 ° C.
As described above, in order to effectively use the exhaust heat, a device that can be driven even when the temperature difference between the low-temperature side heat source and the high-temperature side heat source is small is desired.

In order for the apparatus to operate sufficiently even at a relatively high temperature around the adsorbent, it is necessary to adsorb the adsorbate at a low relative vapor pressure, and to reduce the size of the apparatus by using a small amount of adsorbent. To do so, it is necessary that the amount of adsorption and desorption of the adsorbent is large. In order to use a low-temperature heat source for desorption of adsorbate (regeneration of adsorbent), the desorption temperature needs to be low. That is, (1) adsorbate is adsorbed at low relative vapor pressure (adsorbable at high temperature) as adsorbent used for adsorption heat pump,
There is a demand for an adsorbent that (2) has a large amount of adsorption and desorption and (3) desorbs adsorbates at a high relative vapor pressure (can be desorbed at a low temperature).

[0005] In addition, although the use of various adsorbents has been studied as an adsorbent used in an adsorption heat pump, there are various problems, and a solution is desired.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an efficient adsorption heat pump using an adsorbent capable of adsorbing and desorbing adsorbates in a low relative vapor pressure range.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have found an adsorbent suitable for an adsorption heat pump using adsorption and desorption of adsorbate as a driving source of the apparatus. . That is, the gist of the present invention comprises an adsorbate, an adsorption / desorption section provided with an adsorbent for adsorbing and desorbing the adsorbate, and an evaporating / condensing section connected to the adsorption / desorption section for evaporating / condensing the adsorbate. And a method of operating the adsorption heat pump, wherein the adsorbent is a zeolite containing aluminum, phosphorus, and a hetero atom in a skeleton structure.

Another object of the present invention is to provide an adsorbent, an adsorption / desorption section provided with an adsorbent for adsorbing and desorbing the adsorbate, an evaporating section connected to the adsorption / desorption section for evaporating the adsorbate, An adsorbent heat pump having a condensing section for condensing adsorbate connected to the adsorbing / desorbing section, wherein the adsorbent has a relative vapor pressure of 0.05 or more, 0.3 or more on a water vapor adsorption isotherm measured at 25 ° C.
The present invention resides in an adsorption heat pump, which is an adsorbent having a relative vapor pressure range in which a change in the amount of water adsorbed is 0.18 g / g or more when the relative vapor pressure changes by 0.15 in a range of 0 or less.

[0009] Further, another point is that the relative vapor pressure is not less than 0.05 and 0.3 in the water vapor adsorption isotherm measured at 25 ° C.
When the relative vapor pressure changes by 0.15 within the range of 0 or less, the change in the amount of adsorbed water is 0.18 g / g or more.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The operating vapor pressure range of the adsorption heat pump is as follows: the high-temperature heat source temperature Thigh, the low-temperature heat source temperature Tlow1, the low-temperature heat source temperature Tlow2, and the desorption-side relative vapor pressure φ1 and the adsorption-side relative vapor pressure φ2 obtained from the cold heat generation temperature Tcool.
Is determined by

Φ1 and φ2 are represented by the following equation: Desorption-side relative vapor pressure φ1 = Equilibrium vapor pressure (Tlow1) / Equilibrium vapor pressure (High) Adsorption-side relative vapor pressure φ2 = Equilibrium vapor pressure (Tcool) / Equilibrium vapor pressure (Tlow2) , And the operable relative vapor pressure range is between φ1 and φ2. Here, the high-temperature heat source temperature Thigh is the temperature of the heat medium to be heated when the adsorbate is desorbed from the adsorbent to regenerate the adsorbent, the low-temperature heat source temperature Tlow1 is the temperature of the adsorbate in the condensing section, and the low-temperature heat source temperature Tlow2. Represents the temperature of the heat medium that cools the adsorbent after regeneration together with the adsorption, and the cold generation temperature Tcool refers to the temperature of the adsorbate in the evaporator, that is, the temperature of the generated cold. The equilibrium vapor pressure can be determined from the temperature using the equilibrium vapor pressure curve of the adsorbate.

The operating vapor pressure range in the case where the adsorbate is water will be exemplified below. High temperature heat source temperature 80 ℃, low temperature heat source temperature 3
In the case of 0 ° C., the operating vapor pressure range is φ1 to φ2 = 0.09 to
0.29. Similarly, when the high-temperature heat source temperature is 60 ° C,
Operation relative steam pressure range is φ1 ~ φ2 = 0.21 ~ 0.2
9 Japanese Patent Laid-Open No. 2000-2000 discloses a case in which an adsorption heat pump is driven by using exhaust heat of an automobile engine.
No. 140625 describes in detail. Estimating based on this report, the high-temperature heat source temperature is about 90 ° C,
0 ° C. In this case, the operation relative steam pressure range is φ1 to
φ2 = 0.06 to 0.29.

As described above, when the adsorption heat pump is driven by using the exhaust heat of the gas engine cogeneration, the polymer electrolyte fuel cell, or the automobile engine, the operation relative steam pressure range is φ1 to φ2 = 0.05 to 0.2. 30, and more specifically, φ1 to φ2 = 0.06 to 0.29. That is, a material having a large change in the amount of adsorption in this operating humidity range is preferable. Therefore, a material whose adsorption amount greatly changes in a range of a relative vapor pressure of 0.05 to 0.30, preferably in a range of 0.06 to 0.29 is preferable.

[0014] For example, 3.0 k
It is assumed that a cooling capacity of W (= 10,800 kJ / hr) is obtained. Here, 3.0 kW is a cooling capacity of an air conditioner used for a general automobile air conditioner. It is believed that the capacity of the adsorption heat pump should be at least 15 liters or less based on various vehicle engine room surveys.

Next, the weight of the adsorbent that can be filled in a volume of 15 liters or less is determined. Parts to be placed in the engine room include the main body of the adsorption tower, the evaporator, the condenser and the control valves. It is necessary to reduce the volume of the assembly formed from these components to approximately 15 liters or less. In our study, it is considered that the size of the evaporator, condenser and valves can be formed in about 4.5 liters. Therefore, the capacity of the adsorption tower body is about 10.5 liter or less. Since the filling rate of the adsorbent and the bulk density of the adsorbent in the adsorption tower are usually about 30% and about 0.6 kg / liter, respectively, the adsorbent weight (W) that can be filled is 10.5 × 30%.
× 0.6 = about 1.89 kg.

Next, the characteristics required for the adsorbent will be described. The cooling capacity R in the adsorption heat pump is represented by the following equation A. R = (W · ΔQ · η _C · ΔH / τ) · η _h (Equation A) where W is the weight of the adsorbent packed in one adsorption tower (one side), and ΔQ is the condition during adsorption and desorption. Is the difference between the adsorption amounts (Q2-Q1), η _C is the adsorption amplitude efficiency indicating the ratio of the actual adsorption amplitude within the switching time to the equilibrium adsorption amplitude ΔQ, ΔH is the latent heat of vaporization of water, and τ is the adsorption. The switching time between the process and the desorption process, η _h indicates the heat mass efficiency in consideration of the heat mass loss caused by the adsorbent or the heat exchanger changing the temperature between the hot water temperature and the cooling water temperature.

R is 3 kW and W is 1.89 kg / 2 = 0.9 as described above.
5 kg. Also, from our past studies, τ is about 6
0 sec is appropriate, and the values of ΔH, η _C , and η _h are approximately 2500 kJ / kg, 0.6, and 0.85, respectively. Therefore, when ΔQ is obtained from (Equation A), ΔQ = R / W / η _C / ΔH ・ τ / η _h = 3.0 / 0.95 / 0.6 / 2500 ・ 60/0.
85 = 0.149kg / kg. That is, as an adsorbent used for an adsorption heat pump for automobiles, ΔQ is 0.15 g / g or more,
g / g or more is preferable, and 0.20 g / g or more is more preferable.

An adsorption heat pump utilizes the ability of an adsorbent to adsorb and desorb adsorbates as a driving source. In the adsorption heat pump, water, ethanol, acetone, and the like can be used as the adsorbate, but among them, water is most preferable in view of safety, cost, and the magnitude of latent heat of vaporization.
The adsorbate is adsorbed on the adsorbent as vapor,
A material having a large change in the amount of adsorption in a narrow relative vapor pressure range is preferable. If the change in adsorption amount is large in a narrow relative vapor pressure range,
This is because the amount of adsorbent necessary to obtain the same amount of adsorption under the same conditions can be reduced, and the adsorption heat pump can be driven even if the temperature difference between the cooling heat source and the heating heat source is small.

The adsorbent, which is one of the features of the present invention, is a zeolite containing aluminum, phosphorus and a hetero atom in a skeleton structure. The zeolite mentioned here may be a natural zeolite or an artificial zeolite. Examples of the artificial zeolite include aluminosilicates and aluminophosphates specified by International Zeolite Association (IZA).

Here, among the aluminophosphates, aluminophosphate (Al) which does not contain a hetero atom is used.
PO ₄ -5) is not suitable as an adsorbent of the present invention to indicate a hydrophobic adsorption properties. Aluminum for imparting hydrophilicity to be suitably used as the adsorbent of the present invention,
Part of phosphorus is silicon, lithium, magnesium, titanium, zirconium, vanadium, chromium, manganese,
It is necessary to substitute iron, cobalt, nickel, palladium, copper, zinc, gallium, germanium, arsenic, tin, calcium, boron, or the like.

Among them, zeolite substituted with silicon, magnesium, titanium, zirconium, iron, cobalt, zinc, gallium or boron is preferable, and zeolite substituted with silicon is most preferable, which is commonly called SAPO. I have. These hetero atoms may be substituted with two or more kinds of aluminum and phosphorus in the skeleton.

The zeolite used as the adsorbent in the present invention is a zeolite containing aluminum, phosphorus and a hetero atom in a skeleton structure, and the presence of atoms represented by the following formulas (1), (2) and (3): Those having a ratio are preferred. 0.001 ≦ x ≦ 0.3 (1) (where x represents the molar ratio of hetero atoms to the total of aluminum, phosphorus and hetero atoms in the skeletal structure) 0.3 ≦ y ≦ 0.6 (2) (where y represents the molar ratio of aluminum to the sum of aluminum, phosphorus and heteroatoms in the skeletal structure) 0.3 ≦ z ≦ 0.6 (3) z represents the molar ratio of phosphorus to the total of aluminum, phosphorus, and hetero atoms in the skeletal structure), and among the above-mentioned atomic abundances, the hetero atom abundance is represented by the following formula (4): 0.003 ≦ x ≦ 0.25 (4) (where x is as defined above) is preferable, and the following formula (5) 0.005 ≦ x ≦ 0.2 (5) (5) Wherein x is as defined above).

The zeolite used as an adsorbent in the present invention has a framework density of 10.0 T / 1,0.
Is preferably 00Å ³ or more 16.0T / 1,000Å ³ or less, more preferably 10.0T / 1,000Å ³
Than is 15.0 / 1,000 Å ³ or less in the range of zeolites. Here, the framework density means the number of elements constituting the skeleton other than oxygen 1,000Å per ³ zeolites, this value is one determined by the structure of the zeolite.

The structure of such a zeolite is I
AFG, MER, LI
O, LOS, PHI, BOG, ERI, OFF, PA
U, EAB, AFT, LEV, LTN, AEI, AF
R, AFX, GIS, KFI, CHA, GME, TH
O, MEI, VFI, AFS, LTA, FAU, RH
O, DFO, EMT, AFY, * BEA, etc., preferably AEI, GIS, KFI, CHA, GME, VF
I, AFS, LTA, FAU, RHO, EMT, AF
Y, * BEA.

[0025] The framework density correlates with the pore volume, and generally the lower framework density zeolite has the higher pore volume and therefore the higher adsorption capacity. It is also expected that zeolites that have not been synthesized at present can be suitably used as an adsorbent in the present invention if the framework density is within this range when synthesized. For example, in the case of an aluminophosphate having a CHA structure, a desired adsorption performance can be obtained by using a silicoaluminophosphate known as SAPO-34 in which atoms such as silicon are contained in a skeleton. The method for synthesizing SAPO-34 is described in U.S. Pat. No. 4,440,871 and the like.

The diameter of the pores of the adsorbent is preferably about 3 ° to about 10 ° in view of the adsorption characteristics and strength. Further, when the zeolite is aluminosilicate, silicon in the skeleton, part of aluminum (although in the case of aluminum, there may be all), other atoms, for example, magnesium, titanium, zirconium, vanadium, chromium, manganese,
It may be substituted with iron, cobalt, zinc, gallium, tin, boron and the like. In the case of aluminosilicate, if the molar ratio of silicon to aluminum (aluminum + heteroatom) is too small, as in the case of 13X described above, the compound is rapidly adsorbed in a too low humidity range, and if it is too large, It is too hydrophobic and does not adsorb much water. Therefore, the zeolite used in the present invention generally has a silicon / aluminum molar ratio of 4 or more and 20 or less, preferably 4.5 or more and 18 or less, and more preferably 5 or more and 16 or less.

These zeolites include those having exchangeable cation species. In this case, the cation species include protons, alkali elements such as Li and Na, Mg, and the like.
Examples thereof include alkaline earth elements such as Ca, rare earth elements such as La and Ce, and transition metals such as Fe, Co, and Ni. Protons, alkali elements, alkaline earth elements, and rare earth elements are preferable. Further, proton, Li, Na, K, Mg,
Ca is more preferred. These zeolites may be used alone, in combination, or in combination with other silica, alumina, activated carbon, clay, or the like.

An example of a particularly preferred adsorbent used in the present invention is an aluminophosphate having a CHA structure,
S, which contains atoms such as silicon in the framework structure of zeolite,
APO-34 (framework density = 14.6T / 1,
Silico-alumino-phosphate, which is known as 000Å ^3), and the like. Further, the adsorbent used in the present invention is 2
In the water vapor adsorption isotherm measured at 5 ° C., the relative vapor pressure is 0.1 in the range of 0.05 to 0.30.
5 The adsorbent has a relative vapor pressure range of 0.18 g / g or more, preferably 0.2 g / g or more when the amount of water adsorbed changes, preferably water in the range of 0.05 to 0.20. Is an adsorbent having a change in adsorption amount of 0.18 g / g or more, preferably 0.2 g / g or more. Relative vapor pressure 0.05
As described above, zeolite is a promising material having a water adsorption difference of 0.18 g / g or more when the relative vapor pressure changes by 0.15 or less at 0.30 or less. Since zeolite is a crystal, the pore volume that contributes to adsorption depends on the framework density. 13X which is an example of the zeolite having the lowest framework density (framework density of 12.7 T / 1
000 吸着) is about 0.30 g / g. Therefore, when the adsorption amount at the lower limit of 0.05 of the relative vapor pressure specified by the present invention is more than 0.15 g / g, the adsorption amount difference is 0.1.
It is impossible to obtain 18 g / g. Therefore, the adsorption amount at a relative vapor pressure of 0.05 in the water vapor adsorption isotherm is preferably 0.15 g / g or less, and 0.12 g / g or less,
0.05 g / g or less is more preferable. FIG. 1 shows an adsorption isotherm of water vapor at 25 ° C. of SAPO-34 (manufactured by UOP LLC) measured by an adsorption isotherm measuring apparatus (Belsorb 18: Bell Japan Co., Ltd.). The measurement of the adsorption isotherm was performed at an air high temperature tank temperature of 50 ° C., an adsorption temperature of 25 ° C., an initial introduction pressure of 3.0 torr, an introduction pressure set point of 0, a saturated vapor pressure of 23.76 mmHg, and an equilibration time of 500 seconds. FIG.
Water vapor is rapidly adsorbed at a relative vapor pressure of 0.07 to 0.10, and a relative vapor pressure range of 0.05 to 0.20
It can be seen that the change in the amount of adsorption was 0.25 g / g.
SAPO-34 having such properties is one of the most preferable adsorbents used in the present invention. As described above, the adsorbent used in the present invention has a larger amount of adsorption change in the same relative vapor pressure range as compared with conventional silica gel or zeolite, so that more dehumidification is performed using almost the same weight of adsorbent. Can produce effects.

One of the features of the present invention is that the adsorbent having the above characteristics is used as an adsorbent in an adsorption / desorption portion of an adsorbate of an adsorption heat pump. That is, since a large change in the amount of adsorption can be obtained by a change in the relative vapor pressure in a narrow range, it is suitable for an adsorption heat pump having a limited amount of adsorbent, such as a vehicle air conditioner. Hereinafter, the operation of the adsorption heat pump of the present invention using the above-described adsorbent will be specifically described with reference to the adsorption heat pump having the device configuration shown in FIG. 4, but the adsorption heat pump of the present invention is not limited thereto.

FIG. 4 shows a conceptual diagram of an example of the adsorption heat pump of the present invention. The adsorption heat pump shown in FIG. 4 includes an adsorbent capable of adsorbing and desorbing an adsorbate, and adsorption towers 1 and 2 serving as adsorption and desorption units that are filled with the adsorbent and transfer heat generated by adsorption and desorption of the adsorbate to a heat medium. An evaporator 4 for taking out the cold heat obtained by the evaporation of the adsorbate and a condenser 5 for releasing the heat obtained by the condensation of the adsorbate to the outside. When operating the adsorption heat pump, the operating conditions are determined from the adsorption isotherm at the ambient temperature so that the amount of adsorption and desorption required for the operation can be obtained, and usually the maximum amount of adsorption and desorption can be obtained in operating the apparatus. To be determined. As shown in FIG. 4, the adsorption towers 1 and 2 filled with the adsorbent are connected to each other by an adsorbate pipe 30, and the adsorbate pipe 30 is provided with control valves 31 to 34. Here, the adsorbate exists as adsorbate vapor or a mixture of adsorbate liquid and vapor in the adsorbate pipe.

The evaporator 4 and the condenser 5
Is connected. The adsorption towers 1 and 2 are connected in parallel between the evaporator 4 and the condenser 5, and between the condenser 5 and the evaporator 4, the adsorbate condensed in the condenser is returned to the evaporator 4. Is provided. In addition, reference numeral 41 denotes an inlet of the chilled water for cooling output from the evaporator 4, and reference numeral 51 denotes an inlet of the chilled water to the condenser 5. Reference numerals 42 and 52 denote cold water and a cooling water outlet, respectively. Further, an indoor unit 300 for exchanging heat with an indoor space (air-conditioned space) and a pump 301 for circulating cold water are connected to the cold water pipes 41 and 42. A heat medium pipe 11 is connected to the adsorption tower 1, and a heat medium pipe 21 is connected to the adsorption tower 2, respectively.
Switching valves 115 and 1 are provided at 1 and 21, respectively.
16 and 215 and 216 are provided. Further, the heat medium pipes 11 and 21 flow a heat medium serving as a heating source or a cooling source for heating or cooling the adsorbent in the adsorption towers 1 and 2, respectively. The heating medium is not particularly limited as long as the heating medium can effectively heat and cool the adsorbent in the adsorption tower. Hot water is introduced from inlets 113 and / or 213 by opening and closing switching valves 115, 116, 215, and 216, passes through each adsorption tower 1 and / or 2, and exits 114 and / or 21
4 is derived. The same switching valve 11 is used for cooling water.
5, 116, 215, and 216 open and close,
11 and / or 211, and each adsorber 1 and / or
Or 2 and is derived from outlets 112 and / or 212. Further, an unillustrated outdoor unit, a heat source for generating hot water, and a pump for circulating the heat medium are connected to the heat medium pipes 11 and / or 21 so as to be able to exchange heat with the outside air. The heat source is not particularly limited, and includes, for example, an automobile engine, a cogeneration device such as a gas engine or a gas turbine, and a fuel cell. When used for an automobile, an automobile engine and an automobile fuel cell are preferable examples of the heat source. It is listed as. An operation method of the adsorption heat pump will be described with reference to FIG. In the first step, the control valves 31 and 34 are closed, the control valves 32 and 33 are released, and the regeneration step in the adsorption tower 1 is performed.
The adsorption step is performed in the adsorption tower 2. In addition, the switching valves 115, 116, 215, and 216 are operated so that hot water flows through the heat medium pipe 11 and cooling water flows through the heat medium pipe 21. When the adsorption tower 2 is cooled, cooling water that has been cooled by exchanging heat with outside air, river water, or the like by a heat exchanger such as a cooling tower is introduced through the heat medium pipe 21, and is usually 30 to 40 ° C.
Cool to a degree. In addition, the water in the evaporator 4 evaporates by opening the control valve 32, flows into the adsorption tower 2 as steam, and is adsorbed by the adsorbent. Water vapor transfer is performed by the difference between the saturated vapor pressure at the evaporation temperature and the adsorption equilibrium pressure corresponding to the adsorbent temperature (generally 20 to 50 ° C, preferably 20 to 45 ° C, more preferably 30 to 40 ° C). In the evaporator 4, cold heat corresponding to the heat of vaporization of evaporation, that is, a cooling output is obtained. From the relationship between the temperature of the cooling water in the adsorption tower and the temperature of the cold water generated in the evaporator, the relative vapor pressure on the adsorption side φ2 (where φ2 is the equilibrium vapor pressure of the adsorbate at the temperature of the cold water generated in the evaporator, Divided by the equilibrium vapor pressure of the adsorbate at the temperature of the water).
Is preferably operated so that the adsorbent specified in the present invention is higher than the relative vapor pressure at which water vapor is adsorbed to the maximum.
If φ2 is smaller than the relative vapor pressure at which the adsorbent specified in the present invention adsorbs water vapor at the maximum, the adsorbing ability of the adsorbent cannot be used effectively, and the operation efficiency deteriorates. φ2
Can be appropriately set depending on the environmental temperature and the like.
Is usually 0.20 or more, preferably 0.2
The adsorption heat pump is operated under a temperature condition of 9 or more, more preferably 0.30 or more. Adsorption tower 1 in the regeneration process
Is heated with warm water of usually 40 to 100 ° C., preferably 50 to 98 ° C., more preferably 60 to 95 ° C., and reaches an equilibrium vapor pressure corresponding to the above temperature range, and the condensation temperature of the condenser 5 is 30 to 40 ° C. (Equal to the temperature of the cooling water cooling the condenser). Adsorption tower 1
The water vapor moves to the condenser 5 and is condensed into water.
The water is returned to the evaporator 4 by the return pipe 3. From the relationship between the temperature of the cooling water of the condenser and the temperature of the hot water, the relative vapor pressure on the desorption side φ1 (where φ1 is the equilibrium vapor pressure of the adsorbate at the temperature of the cooling water of the condenser and the equilibrium of the adsorbate at the temperature of the hot water) Determined by dividing by the vapor pressure), it is preferable to operate φ1 so as to be smaller than the relative vapor pressure at which the adsorbent rapidly adsorbs water vapor. If φ1 is larger than the relative vapor pressure at which the adsorbent rapidly adsorbs water vapor,
This is because the excellent adsorption amount of the adsorbent cannot be used effectively. φ1 can be appropriately set depending on the environmental temperature and the like, but the adsorption heat pump is operated under a temperature condition in which the adsorption amount at φ1 is usually 0.06 or less, preferably 0.05 or less. The difference between the amount of adsorbate adsorbed at φ1 and the amount of adsorbate adsorbed at φ2 is usually 0.18 g / g or more, preferably 0.20 g / g or more, and more preferably 0.25 g / g or more. Drive like so. The above is the first
It is a process. In the next second step, the adsorption tower 1 performs the adsorption step,
Control valves 31 to 3 so that the adsorption tower 2 is in the regeneration step.
4 and switching valves 115, 116, 215, and 2
By switching 16, cool heat, that is, cooling output can be obtained from the evaporator 4. The continuous operation of the adsorption heat pump is performed by sequentially switching the above first and second steps. Here, the operation method in the case where two adsorption towers are installed has been described. However, by appropriately desorbing the adsorbate adsorbed by the adsorbent, a state in which one of the adsorption towers can adsorb the adsorbate is maintained. If possible, any number of adsorption towers may be installed.

[0032]

As the adsorbent for the adsorption heat pump,
Generally, zeolite with a silica gel to low silica alumina ratio has been used. However, the adsorbents conventionally used in adsorption heat pumps have insufficient adsorption / desorption capacity to use a relatively low-temperature heat source as a drive source for the adsorption heat pump. For example, considering a 13X water vapor adsorption isotherm as a typical example of a zeolite for an adsorption heat pump, the water vapor is rapidly adsorbed at a relative vapor pressure of 0.05 or less, and in a relative vapor pressure region higher than 0.05, the water vapor adsorption amount of the zeolite is It does not change. When regenerating the adsorbent, the relative humidity of the surrounding gas is reduced to desorb and remove the water once adsorbed, but it is necessary to lower the relative vapor pressure to desorb the water adsorbed on the zeolite 13X. Therefore, it is said that a heat source of 150 ° C. to 200 ° C. is required. In general, zeolite is excellent in water adsorption ability, but has a drawback that once adsorbed, the adsorbate is difficult to desorb and a high-temperature heat source is required for regeneration. Recently, mesoporous molecular sieves synthesized using the micelle structure of a surfactant as a template (such as FSM-10)
Zeolites such porous aluminum phosphate molecular sieves called (JP 9-178292) and known as AlPO ₄ (Japanese Patent Laid-Open No. 11-197439) has been studied. Mesoporous molecular sieve (FS
M-10) is a promising material with a large difference in adsorption amount of 0.25 g / g in the range of relative vapor pressures of 0.20 and 0.35 (JP-A-9-178292: graph 4 in FIG. 14; FS).
M-10). However, the amount of adsorption is small in the range of the relative vapor pressure of 0.05 to 0.30, which is an example of the operation of the adsorption heat pump of the present invention. Among them, the change in the amount of adsorption is large in the range of the relative vapor pressure of 0.15 to 0.30, but the difference in the amount of adsorption at this time is 0.08 g / g, and the performance of the adsorption heat pump must be inferior. . In addition, it has been pointed out that repeated use causes the structure to collapse and the function as an adsorbent to be deteriorated, and durability is an issue. For example, an AFI type porous aluminum phosphate molecular sieve shown in FIG. 3 (framework density = 17.5 T / 1,
000Å ³⁾ adsorption isotherm of ALPO-5 zeolite (Colloid Polym Sci 277, p
83-88 (1999), FIG. 1 (adsorption temperature 30
C)), the adsorption amount of ALPO-5 sharply increases in the range of relative vapor pressure of 0.25 to 0.40 and increases in the range of relative vapor pressure of 0.05 to 0.3. It is possible to adsorb and desorb, but the relative vapor pressure is 0.15 to 0.3
The change in the amount of adsorption in the range of 0 was 0.14 g / g. Silica gel type A (Fuji Silysia Chemical Ltd.), which is known as an adsorbent suitable for an adsorption heat pump, was measured with an adsorption isotherm measuring device (Belsorb 18: Bell Japan Co., Ltd.). The adsorption isotherm is shown in FIG. In addition, this measurement was performed on the same conditions as SAPO-34 of FIG. According to the adsorption isotherm of the silica gel type A in FIG. 2, the silica gel type A can obtain an adsorption amount almost proportional to the relative water vapor pressure in the range of the relative water vapor pressure of 0 to 0.7. However, the same relative vapor pressure as that of a mesoporous molecular sieve or a porous aluminum phosphate molecular sieve is used.
0.08 g of A-type silica gel in the range of 15 to 0.30
/ G only changes the adsorption amount. Adsorption heat pumps using silica gel as an adsorbent have been commercialized, but the small difference in the amount of adsorption has forced the equipment to be large. According to the present invention, the relative vapor pressure is 0.05 or more, 0.3
An adsorption heat pump using an adsorbent that shows a large change in the amount of adsorption and desorption in the range of 0 or less has a large difference in the amount of water adsorbed due to the adsorption and desorption of the adsorbent, and the adsorbent can be regenerated (desorbed) at a low temperature. In addition, the adsorption heat pump can be efficiently driven by using a heat source having a lower temperature than in the related art. That is, according to the adsorbent of the present invention, an adsorption heat pump driven by a relatively low-temperature heat source of 100 ° C. or lower can be provided.

[Brief description of the drawings]

FIG. 1 is a water vapor adsorption isotherm of SAPO-34.

FIG. 2 is a water vapor adsorption isotherm of silica gel type A.

FIG. 3 is a water vapor adsorption isotherm of ALPO-5.

FIG. 4 is a conceptual diagram of an adsorption heat pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Adsorption tower 2 Adsorption tower 3 Adsorbate piping 4 Evaporator 5 Condenser 11 Heat medium piping 111 Cooling water inlet 112 Cooling water outlet 113 Hot water inlet 114 Hot water outlet 115 Switching valve 116 Switching valve 21 Heat medium piping 211 Cooling water inlet 212 Cooling Water outlet 213 hot water inlet 214 hot water outlet 215 switching valve 216 switching valve 30 adsorbate pipe 31 control valve 32 control valve 33 control valve 34 control valve 300 indoor unit 301 pump 41 cold water pipe (inlet) 42 cold water pipe (outlet) 51 cooling water Piping (inlet) 52 Cooling water piping (outlet)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takahiko Takewaki 1000, Kamoshidacho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Inside Mitsubishi Chemical Corporation (72) Inventor Katsushi Fujii 1000, Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Mitsubishi Chemical Corporation In-company (72) Inventor Masanori Yamazaki 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation F-term (reference) 3L093 NN04 4G066 AA61B BA36 BA38 CA43 EA20 FA37

Claims (17)

[Claims] 1. An adsorption / desorption unit including an adsorbate, an adsorbent for adsorbing and desorbing the adsorbate, an evaporating unit connected to the adsorption / desorption unit for evaporating the adsorbate, and connected to the adsorption / desorption unit. Heat pump comprising a condenser for condensing the adsorbate,
An adsorption heat pump, wherein the adsorbent is a zeolite having a skeleton structure containing aluminum, phosphorus, and a hetero atom. 2. A zeolite containing aluminum, phosphorus and a hetero atom in a skeletal structure is represented by the following formulas (1), (2) and (3): 0.001 ≦ x ≦ 0.3 (1) In the formula, x represents the molar ratio of hetero atoms to the total of aluminum, phosphorus, and hetero atoms in the skeletal structure. 0.3 ≦ y ≦ 0.6 (2) (in the formula, y is aluminum in the skeletal structure) 0.3 ≦ z ≦ 0.6 (3) (wherein z represents the total amount of aluminum, phosphorus and hetero atoms in the skeletal structure) The adsorption heat pump according to claim 1, wherein the adsorption heat pump has a proportion of atoms represented by the following formula: 3. The adsorption heat pump according to claim 1, wherein the heteroatom is silicon. 4. An adsorbate, an adsorption / desorption section having an adsorbent for adsorbing and desorbing the adsorbate, an evaporator connected to the adsorption / desorption section for evaporating the adsorbate, and connected to the adsorption / desorption section. Heat pump comprising a condenser for condensing the adsorbate,
When the relative vapor pressure of the adsorbent changes by 0.15 in the range of 0.05 to 0.30 in the water vapor adsorption isotherm measured at 25 ° C., the change in the amount of water adsorbed is 0.
An adsorbent having a relative vapor pressure range of 18 g / g or more,
Adsorption heat pump. 5. The adsorption amount of the adsorbent at a relative vapor pressure of 0.05 in a water vapor adsorption isotherm measured at 25 ° C. is 0.
The adsorption heat pump according to claim 4, which has a weight of 15 g / g or less. 6. The adsorption material is a zeolite, the framework density of 10.0T / 1,000Å ³ or more,
16.0T / claim 4 1,000 Å ³ or less of the range
Or the adsorption heat pump according to 5. 7. The adsorption heat pump according to claim 4, wherein the adsorbent is a zeolite having a skeleton structure containing aluminum, phosphorus and a hetero atom. 8. The zeolite according to the following formula (1) or (2)
And (3) 0.001 ≦ x ≦ 0.3 (1) (in the formula, x represents a molar ratio of a hetero atom to the total of aluminum, phosphorus and hetero atoms in the skeletal structure) 0.3 ≦ y ≦ 0.6 (2) (in the formula, y represents a molar ratio of aluminum to the total of aluminum, phosphorus, and a hetero atom in the skeletal structure) 0.3 ≦ z ≦ 0.6 ( 3) The adsorption according to claim 6 or 7, wherein the compound has an abundance of atoms represented by (wherein z represents a molar ratio of phosphorus to the total of aluminum, phosphorus and heteroatoms in the skeleton structure). heat pump 9. The adsorption heat pump according to claim 7, wherein the heteroatom is silicon. 10. An air conditioner for a vehicle, wherein the adsorption heat pump according to any one of claims 1 to 9 is used for air conditioning in a vehicle cabin. 11. An adsorption / desorption section including an adsorbate, an adsorbent for adsorbing and desorbing the adsorbate, an evaporator connected to the adsorption / desorption section for evaporating the adsorbate, and connected to the adsorption / desorption section. Heat pump provided with a condensing part for condensing adsorbate, wherein the difference between the amount of adsorption at the desorption-side relative vapor pressure φ1 and the amount of adsorption at the adsorption-side relative vapor pressure φ2 is 0.18 g / g or more. Operating method of adsorption heat pump characterized in that it operates with 12. In the water vapor adsorption isotherm measured at 25 ° C., when the relative vapor pressure changes by 0.15 in the range of 0.05 to 0.30, the change in the amount of water adsorbed is 0.1%. An adsorbent for an adsorption heat pump comprising an adsorbent having a relative vapor pressure range of 18 g / g or more. 13. The water vapor adsorption isotherm measured at 25 ° C. has an adsorption amount of 0.15 g / g at a relative vapor pressure of 0.05.
The adsorbent for an adsorption heat pump according to claim 12, which is: 14. adsorbing material is a zeolite, the framework density of 10.0T / 1,000Å ³ or more, according to claim 12 or 13 in the range of 16.0T / 1,000Å ³ or less Adsorbent for adsorption heat pump. 15. The adsorbent for an adsorption heat pump according to claim 12, wherein the adsorbent is a zeolite containing aluminum, phosphorus, and a hetero atom in a skeleton structure. 16. The zeolite according to the following formula (1) or (2)
And (3) 0.001 ≦ x ≦ 0.3 (1) (in the formula, x represents a molar ratio of a hetero atom to the total of aluminum, phosphorus and hetero atoms in the skeletal structure) 0.3 ≦ y ≦ 0.6 (2) (in the formula, y represents a molar ratio of aluminum to the total of aluminum, phosphorus, and a hetero atom in the skeletal structure) 0.3 ≦ z ≦ 0.6 ( 3) The adsorption according to claim 14 or 15, wherein the compound has an abundance of atoms represented by the formula (wherein, z represents a molar ratio of phosphorus to the total of aluminum, phosphorus and heteroatoms in the skeletal structure). Adsorbent for heat pump. 17. The adsorbent for an adsorption heat pump according to claim 15, wherein the hetero atom is silicon.