JP2009275938A - Adsorption type heat pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adsorption type heat pump capable of saving labor for troublesome maintenance while avoiding a fall of an output by collecting gas molecules other than an adsorbate existing in a sealed container. <P>SOLUTION: A gas collecting heat exchanger 22 and adsorption/desorption heat exchangers 23, 24 to which adsorbents are applied are built in the sealed container 21 to form each of adsorption tanks 2a, 2b. After the preparatory operation of evacuating by a vacuum pump 5 while carrying out desorption by circulating and supplying a high temperature heat medium to a total enthalpy heat exchanger, an adsorption process in one adsorption tank and a desorption process in the other adsorption tank are alternately repeated as cold takeout operation. During the cold takeout operation, a gas collecting heat medium of a predetermined temperature is supplied to the gas collecting heat exchanger to adsorb and collect unnecessary gas molecules discharged, intruding and produced in the sealed container. A collecting capacity can be regenerated and recovered by periodically performing the same processing as the preparatory operation as maintenance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is an adsorptive heat pump using an adsorptive refrigeration cycle, and particularly collects gas molecules other than adsorbate that may enter, release, or generate in the adsorption tank. The present invention relates to an adsorption heat pump capable of avoiding a decrease in output.

  Conventionally, as this type of adsorption heat pump, when a plurality of adsorbers, evaporators, condensers, a plurality of switching valves, etc. are housed in one vacuum container, the degree of vacuum of each device is individually managed. A device that avoids complexity and facilitates management of the degree of vacuum of each device is known (see, for example, Patent Document 1).

  In addition, the vacuum vessel is evacuated, and liquid molecules in the vacuum vessel are condensed or adsorbed and held on a cryopanel that has been supplied with liquid helium from a refrigerator and lowered to an extremely low temperature. There is also known a vacuum cryopump that evacuates the interior to make the inside vacuum (see, for example, Patent Document 2).

Japanese Patent No. 3931964 JP-A-6-58257

  By the way, in order to perform an operation for taking out cold heat using an adsorption heat pump using a refrigeration cycle, only the adsorbate in the gas phase state or the liquid phase state exists in the sealed container, and there is no gas molecule other than the adsorbate. Thus, it is necessary to maintain a substantially vacuum state. For this reason, in the adsorption heat pump, in the initial preparation operation before the start of the cold heat extraction operation, the adsorber is maintained at a high temperature to promote gas desorption from the adsorbent, and the inside of the sealed container constituting the adsorption tank is a vacuum pump Evacuate for a long time, and then keep the deaerated adsorbate (for example, water, degassed water after expelling dissolved gas by evacuating) in a vacuum state A preparatory process of sealing in the sealed container (the evaporation chamber constituting the adsorption tank) is performed.

However, in such an adsorption heat pump, when gas molecules other than the adsorbate are present in a sealed container maintained in a vacuum state, the output in the cold extraction operation (work rate or heat transfer amount per unit time) Will be reduced. For example, when water is enclosed as an adsorbate, if there is a gas other than the water or water vapor (for example, N ₂ , O ₂ , CO ₂ , H ₂ ), water is adsorbed when the adsorbate water is evaporated. As a result, the time required to evaporate a predetermined amount of water becomes longer and the operation time of one cycle for taking out the cold takes longer. It will cause a decline.

The gas as described above is, for example, a gas that has entered from a seal portion that is necessary for a connection portion with a vacuum pump, that is, a small amount of air from the outside or remains adsorbed by an adsorbent. Gas molecules that remain adsorbed on metal surfaces of molecules and heat exchangers (outgas)
There is a possibility that it will be released later in the sealed container, or the adsorbate water sealed inside may cause a chemical reaction to generate gas, and so on. Therefore, it is difficult to keep the inside of the above-mentioned sealed container in a vacuum state in which only adsorbate water or water vapor is permanently sealed. Therefore, the vacuum pump is periodically operated to close the inside of the sealed container. Maintenance for re-vacuum is performed to evacuate.

  In addition, in order to collect gas molecules other than the adsorbate as described above (hereinafter collectively referred to as “unnecessary gas molecules”), it is also possible to install or apply a getter capable of selective chemical adsorption in a sealed container. However, it is necessary to replace or regenerate before the adsorbable capacity is exceeded, and in maintenance for the replacement or regeneration, it is necessary to open and close the sealed container each time and reclose it. It will be accompanied by a great deal of effort.

  The present invention has been made in view of such circumstances, and its purpose is to collect gas molecules other than the adsorbate present in the hermetic container while avoiding the occurrence of a decrease in output. An object of the present invention is to provide an adsorption heat pump that can save laborious maintenance.

  In order to achieve the above object, the invention according to claim 1 includes an adsorption refrigeration cycle that includes one or more adsorption tanks, a condensation tank, and an evaporation tank, and repeats adsorption and desorption of adsorbate. The following specific matters were prepared for the adsorption heat pump to be executed. That is, as the adsorption tank, a sealed container, at least one adsorption / desorption heat exchanger built in the sealed container and alternately switched between the adsorption process and the desorption process, and the adsorbate in the sealed container It comprises at least one gas collection heat exchanger that adsorbs other gases, and is set as the gas collection heat exchanger as the gas collection heat exchanger. The heating medium having the above temperature is circulated and supplied.

  In the case of this invention, gas molecules (unnecessary gas molecules) other than the adsorbate in the closed vessel constituting the adsorption tank are adsorbed and collected by the gas repairing heat exchanger and maintained in the collected state. become. As a result, the vacuum state in the sealed container is maintained, and it is possible to avoid the occurrence of a decrease in output due to the presence of unnecessary gas molecules other than the adsorbate. Moreover, in order to regenerate the adsorption capacity of the heat exchanger for collecting gas, it is only necessary to perform a maintenance operation just to switch the supply to the desorption high-temperature heat medium, it is not necessary to disassemble to open the sealed container, This will save a lot of maintenance work.

  The invention according to claim 2 is directed to an adsorption heat pump that includes one or more adsorption tanks, a condensation tank, and an evaporation tank and that performs an adsorption refrigeration cycle that repeats adsorption and desorption of adsorbate. The following specific matters were prepared. That is, the adsorption tank includes a sealed container and at least two adsorption / desorption heat exchangers built in the sealed container, and one of the at least two adsorption / desorption heat exchangers. One adsorption / desorption heat exchanger is configured as a gas collecting heat exchanger that adsorbs a gas other than the adsorbate in the sealed container, and the other adsorption / desorption heat exchangers have an adsorption process and a desorption process. Is configured to be selectively executed.

  In the case of this invention, as in the case of the invention according to claim 1, unnecessary gas molecules in the sealed container constituting the adsorption tank are adsorbed and collected by the gas repairing heat exchanger, and in the collected state. Will be maintained. As a result, the vacuum state in the sealed container is maintained, and it is possible to avoid the occurrence of a decrease in output due to the presence of unnecessary gas molecules other than the adsorbate. Moreover, in order to regenerate the adsorption capacity of the heat exchanger for collecting gas, it is only necessary to perform a maintenance operation just to switch the supply to the desorption high-temperature heat medium, it is not necessary to disassemble to open the sealed container, This will save a lot of maintenance work. In addition, any one of at least two adsorption / desorption heat exchangers may be used as the gas collection heat exchanger, and it is not necessary to provide a special gas collection heat exchanger. .

  As described above, according to the adsorption heat pump of claim 1 or claim 2, the unnecessary gas molecules in the sealed container constituting the adsorption tank can be adsorbed and collected by the gas repairing heat exchanger. Can be maintained in the collected state. As a result, it is possible to reliably maintain the vacuum state in the sealed container, and to avoid the occurrence of a decrease in output due to the presence of unnecessary gas molecules other than the adsorbate. Moreover, in order to regenerate the adsorption capacity of the heat exchanger for collecting gas, it is only necessary to perform a maintenance operation by simply switching the supply to a demountable high-temperature heat medium, omitting the need to disassemble the sealed container, and performing maintenance work. It will be possible to achieve significant labor savings.

  In particular, according to claim 2, any one of at least two adsorption / desorption heat exchangers may be used as the gas collection heat exchanger, and a special gas collection heat exchanger may be used. Therefore, the adsorption heat pump of the present invention can be easily configured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an operation principle of an adsorption heat pump according to an embodiment of the present invention, and this adsorption heat pump includes a pair of adsorption tanks 2a and 2b, a condensation tank 3, and an evaporation tank 4. It is. Each of the tanks 2a, 2b, 3 and 4 is formed by a sealed container having a built-in heat exchanger, and is maintained in a predetermined vacuum state by the vacuum pumps 5 and 5 or the like. Each adsorption tank 2a, 2b can be connected to the condensing tank 3 via the open / close switching valves 61, 62, and can be connected to the evaporation tank 4 via the open / close switching valves 63, 64. In addition, the condensing tank 3 can be connected to the evaporating tank 4 through an open / close switching valve 65. In particular, the evaporation tank 4 is filled with a required amount of adsorbate such as water, alcohol, and ammonia. Hereinafter, the description will be continued assuming that water is enclosed as an adsorbate.

  First, an operation for taking out the cold based on the adsorption refrigeration cycle using the adsorption heat pump will be briefly described. This operation enables continuous cooling and taking out by a batch processing system in which the adsorption process and the desorption process are alternately switched between the pair of adsorption tanks 2a and 2b. That is, as a batch process in a certain cycle, the supply of water vapor evaporated from the evaporation tank 4 through the open / close switching valve 63 is performed, and the adsorption process is performed in one adsorption tank (for example, 2a), while the other The desorbed water vapor is supplied to the condensing tank 3 through the open / close switching valve 62 that has been subjected to the desorption process in the adsorption tank 2b and is converted into an open state, and is condensed. Then, in the batch processing of the next cycle, the steps in the pair of adsorption tanks 2a and 2b are switched to each other, the desorption process is performed in the adsorption tank 2a, and the adsorption process is performed in the adsorption tank 2b. That is, in the adsorption tank 2a, the water vapor adsorbed in the previous cycle is desorbed and supplied to the condensation tank 3 through the open / close switching valve 61, and in the adsorption tank 2b, the adsorbent after desorption in the previous cycle is removed from the evaporation tank 4. The water vapor is supplied through the open / close switching valve 64 to be adsorbed. Such a cycle is repeated alternately.

  In this cycle, for example, in the adsorption tank 2a, the supply medium is supplied and switched alternately in the order of low temperature-high temperature-low temperature-high temperature as a heat medium circulatingly supplied to the built-in adsorption / desorption heat exchanger. The adsorption-desorption-adsorption-desorption process is alternately repeated. On the other hand, in the adsorption tank 2b, the supply of the heat medium circulated in the opposite direction to the adsorption tank 2a is alternately switched between high temperature-low temperature-high temperature-low temperature. The process is switched as follows: desorption-adsorption-desorption-adsorption. By doing in this way, the evaporation in the evaporation tank 4 and the condensation in the condensation tank 3 are continuously performed, and the heat medium circulated and supplied to the evaporation tank 4 is cooled by the evaporation heat and returned. The cold heat can be continuously taken out by the cooled heat medium.

  Next, the adsorption tanks 2a and 2b employed in the present embodiment will be described with reference to FIG. Both adsorption tanks 2a and 2b have the same configuration, and each includes a sealed container 21 and two or more (three in the illustrated example) heat exchangers 22, 23, and 24 built in the sealed container 21. Has been. Of the three, one heat exchanger 22 is a gas collecting heat exchanger, and the remaining heat exchangers 23 and 24 are adsorption / desorption heat exchangers. These three heat exchangers 22, 23, and 24 all have the same configuration, and adsorbents such as zeolite, silica gel, or activated carbon are fixed to the outer surfaces thereof. For example, in the case of the fin and tube type, the adsorbent 203 is fixed in layers on the outer surfaces of the fins 201, 201,...

  Although not shown, each of the adsorption / desorption heat exchangers 23, 24 has either a high temperature (for example, 75 ° C.) heat medium or a medium temperature (for example, 32 ° C.) heat medium. A heat medium supply pipe is connected so as to be circulated and supplied so that supply can be switched. That is, when an intermediate temperature heat medium (a low temperature heat medium of two types of high and low temperatures) is circulated and supplied to the adsorption / desorption heat exchangers 23 and 24, the adsorption tank 2a or 2b becomes an adsorption step. The adsorbent on the outer surface is cooled and acts as an adsorber that adsorbs water vapor, which is a gaseous adsorbate. Conversely, if a high-temperature heat medium is circulated and supplied, The tank 2a or 2b comes to perform a desorption process and serves as a desorber for desorbing (separating) water vapor that has already been adsorbed by the adsorbent.

  On the other hand, the gas collecting heat exchanger 22 is supplied with either a heating medium at a predetermined temperature for adsorption of unnecessary gas molecules or a heating medium at a high temperature (for example, 75 ° C.) for preparatory operation or maintenance. A heat medium supply pipe is connected so as to be circulated and supplied as possible. As the temperature of the heating medium to be circulated and supplied for the adsorption of unnecessary gas molecules, the temperature at which only the unnecessary gas molecules can be adsorbed and retained without adsorbing water vapor (adsorbate) is most desirable. Even if the adsorption of water vapor occurs, a temperature that can suppress the adsorption of water vapor as much as possible and adsorb and hold unnecessary gas molecules may be adopted. Such a temperature value includes an evaporation operation for the evaporation heat exchanger of the evaporation tank 4 from the medium heat medium temperature (for example, 32 ° C.) circulated and supplied to the adsorption / desorption heat exchangers 23, 24. What is necessary is just to employ | adopt the temperature value of the range to the low-temperature heat-medium temperature (for example, 20 degreeC) circulated and supplied for the purpose. Here, the temperature of the heating medium that is circulated and supplied for adsorption of unnecessary gas molecules may be set to a temperature value similar to the intermediate temperature for adsorption. It is preferable to set. Even if a slight amount of water vapor is adsorbed due to the adsorption of unnecessary gas molecules, the degree of decrease in output can be reduced rather than continuing the cold heat extraction operation in a state where unnecessary gas gas molecules are mixed. This is because the maintenance labor can be saved as will be described later. Alternatively, for the same reason, a temperature value having a temperature difference by a predetermined temperature on the lower temperature side than the heat medium temperature supplied to the adsorption / desorption heat exchangers 23 and 24 in the same adsorption tank 2a or 2b is unnecessary. You may make it set as a heat-medium temperature circulatingly supplied for adsorption | suction of a gas molecule. For example, when three types of heat medium supply, high temperature, medium temperature, and low temperature, are possible, a high temperature (for example, 75 ° C.) heat medium is supplied to the adsorption / desorption heat exchangers 23 and 24 for desorption. When it is, a medium temperature (for example, 32 ° C.) heat medium is supplied to the gas collection heat exchanger 22, and a medium temperature (for example, 32 ° C.) heat medium is used for adsorption in the adsorption / desorption heat exchangers 23 and 24. When supplied, a low-temperature (for example, 20 ° C.) heating medium may be supplied to the gas-collecting heat exchanger 22.

  Next, the operation state of the adsorption tanks 2a and 2b during the preparation operation of the adsorption heat pump of the present embodiment, the cold heat extraction operation that repeats the adsorption / desorption cycle, and the maintenance operation will be described. In the preparation operation, the inside of the sealed container 21 is evacuated by operating the vacuum pump 5 while circulatingly supplying a high-temperature heat medium to the total heat exchangers 22, 23, and 24, respectively. As a result, gas molecules and the like that may be adsorbed and collected by the adsorbents of the heat exchangers 22, 23, and 24 are sufficiently desorbed (see FIG. 2) and maintained in a predetermined vacuum state. .

  The cold extraction operation by the batch processing method as described above is started in a state maintained in this vacuum state. When one of the adsorption tanks (for example, 2a) is in the adsorption process, as shown in FIG. 3, the water vapor evaporated from the evaporation tank 4 (see FIG. 1) through the open / close switching valve 63 is sealed container 21. The water vapor is introduced into the inside and adsorbed by the adsorption / desorption heat exchangers 23 and 24, while unnecessary gas molecules in the sealed container 21 are adsorbed by the gas collection heat exchanger 22. In parallel with this, a desorption process is performed in the other adsorption tank (for example, 2b), and as shown in FIG. 4, an open / close switching valve in which the water vapor desorbed from the adsorption / desorption heat exchangers 23 and 24 is opened and converted. On the other hand, the gas collection heat exchanger 22 continues to adsorb unnecessary gas molecules in the sealed container 21 while being led to the condensation tank 3 (see FIG. 1) through 62. Thus, while the cold extraction operation | movement which repeats an adsorption process and a desorption process is performed in adsorption tank 2a, 2b, it is for gas collection heat exchanger 22 in each adsorption tank 2a, 2b for gas collection. The heat medium having a predetermined temperature is continuously supplied in a circulating manner, whereby the gas collection heat exchanger 22 continues to collect and hold unnecessary gas molecules in the sealed container 21.

  Then, the maintenance operation after a predetermined time has elapsed is performed in order to desorb unnecessary gas molecules adsorbed and collected by the gas collection heat exchanger 22 and discharge them outside the sealed container 21. This maintenance operation only needs to perform the same processing as the above-described preparation operation. That is, while the high-temperature heat medium is circulated and supplied to the total heat exchangers 22, 23, and 24, the vacuum pump 5 is operated to evacuate the sealed container 21. Thereby, the unnecessary gas molecules adsorbed and collected by the adsorbent of the gas collection heat exchanger 22 and the water vapor adsorbed by the adsorbents of the adsorption / desorption heat exchangers 23 and 24 are desorbed. The desorbed unnecessary gas molecules and the like are discharged by evacuation by the vacuum pump 5. Then, the sealed container 21 is maintained in a predetermined vacuum state for the next cold heat extraction operation. With the above maintenance operation, the ability to collect unwanted gas molecules by the gas collection heat exchanger 22 can be recovered and regenerated easily and quickly.

  In the case of the adsorption heat pump described above, unnecessary gas molecules in the sealed container 21 constituting the adsorption tanks 2a and 2b are adsorbed and collected by the gas repairing heat exchanger 22 and maintained in the collected state. it can. Thereby, the vacuum state in the sealed container 21 can be maintained, and the occurrence of a decrease in output due to the presence of unnecessary gas molecules other than water and water vapor (adsorbate) can be avoided. In particular, the heat exchangers 22, 23, and 24 are not completely removed from the heat exchangers 22, 23, and 24 even by desorption and evacuation in the initial preparation operation before the start of service, and are gradually released into the sealed container 21 as the cold heat extraction operation proceeds. The unnecessary gas molecules can be reliably collected, the pressure in the adsorption tanks 2a and 2b increases due to the unnecessary gas molecules, and as a result, the occurrence of a situation where the output decreases, It can be reliably prevented. Furthermore, the trapping ability of unnecessary gas molecules can be adjusted by adjusting the adsorbent of the heat exchanger 22 for trapping gas and the temperature of the heat medium for trapping gas, thereby reaching the ability to adsorb unnecessary gas molecules. In other words, it is possible to extend the elapsed time until the output starts to decrease. For this reason, it becomes possible to extend the duration of the cold heat extraction operation until the next maintenance operation. Moreover, in order to regenerate the adsorption capacity of the adsorbent in the heat exchanger 22 for collecting gas, it is only necessary to perform a maintenance operation by switching the supply to a high-temperature heat medium to be removed, and it is necessary to disassemble to open the sealed container. As a result, there is a significant labor saving in maintenance work.

<Other embodiments>
In addition, this invention is not limited to the said embodiment, Other various embodiment is included. That is, in the said embodiment, although the adsorption | suction type heat pump provided with a pair of adsorption tanks was shown, not only this but at least one adsorption tank should just be provided, and three or more adsorption tanks are provided. May be configured.

  In the above embodiment, the adsorption tank includes three identical heat exchangers, ie, two adsorption / desorption heat exchangers 23 and 24 and one gas collection heat exchanger 22. However, the total number may be two or more, and the size and configuration of the gas collection heat exchanger may be larger or smaller than the adsorption / desorption heat exchanger. In short, it is sufficient that the number of adsorption / desorption heat exchangers is at least one, and at least one gas collecting heat exchanger is sufficient. In other words, the adsorption tank may be constituted by at least one adsorption / desorption heat exchanger and at least one gas collection heat exchanger.

  As the adsorption / desorption heat exchangers 23 and 24 and the gas collection heat exchanger 22, the fin-and-tube type is shown, but not limited to this, other types of heat exchangers may be used. .

  Although the vacuum pump 5 is attached to each of the adsorption tanks 2a and 2b, only one vacuum pump may be provided.

It is a block diagram which shows the basic composition of the adsorption heat pump of embodiment of this invention. It is explanatory drawing which shows the adsorption tank of embodiment of this invention. FIG. 3 is a view corresponding to FIG. 2 showing the adsorption tank in a state in the adsorption process. FIG. 3 is a view corresponding to FIG. 2 showing the adsorption tank in a state of being in a desorption process.

Explanation of symbols

2a, 2b Adsorption tank 3 Condensation tank 4 Evaporation tank 21 Sealed container 22 Gas exchanger heat exchanger 23, 24 Adsorption / desorption heat exchanger

Claims (2)

An adsorption heat pump comprising one or more adsorption tanks, a condensation tank, and an evaporation tank, wherein an adsorption refrigeration cycle that repeats adsorption and desorption of adsorbate is executed,
The adsorption tank includes a sealed container, at least one adsorption / desorption heat exchanger built in the sealed container and alternately switched between an adsorption process and a desorption process, and an adsorbate other than the adsorbate in the sealed container. Comprising at least one gas collection heat exchanger to which gas is adsorbed,
The gas collection heat exchanger is configured such that a heat medium having a temperature set for gas adsorption is circulated and supplied to the gas collection heat exchanger. heat pump. An adsorption heat pump comprising one or more adsorption tanks, a condensation tank, and an evaporation tank, wherein an adsorption refrigeration cycle that repeats adsorption and desorption of adsorbate is executed,
The adsorption tank is configured to include a sealed container and at least two adsorption / desorption heat exchangers built in the sealed container,
One adsorption / desorption heat exchanger of the at least two adsorption / desorption heat exchangers is configured as a gas collection heat exchanger that adsorbs a gas other than the adsorbate in the sealed container, An adsorption heat pump, wherein an adsorption process and a desorption process are selectively performed by an adsorption / desorption heat exchanger.

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