JPH08178461A - Method for controlling adsorption freezer - Google Patents

Abstract

PURPOSE: To provide a method for controlling an adsorption freezer capable of applying a high freezing load from the beginning of its operation in a simple configuration. CONSTITUTION: In an adsorption freezer comprising a refrigerant chamber 5 having refrigerant stored therein, an adsorption chamber 3 for storing adsorption substances adsorbing refrigerant vapor generated from the refrigerant chamber 5, wherein the adsorption chamber 3 is provided with an electrical heater 4 and further there is provided a vapor passage 9 for communicating with the refrigerant chamber 5 and the adsorption chamber 3 from each other, a pre-cooling step for adsorbing refrigerant for the adsorption substance at the adsorption chamber is carried out. Since a temperature of the refrigerant chamber 5 can be reduced sufficiently at the pre-cooling stage, it is possible to get a high freezing load with a simple configuration from the beginning of the operation of the freezing and heat exchanging cycle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adsorption system in which the vapor of a refrigerant such as water is adsorbed by an adsorbent such as zeolite or silica gel, and the heat generated during adsorption of the refrigerant vapor and the latent heat of vaporization during evaporation of the refrigerant are utilized. The present invention relates to a refrigerator control method.

[0002]

2. Description of the Related Art An adsorption type air conditioner (adsorption type refrigerator) as disclosed in JP-A-5-141807 and JP-A-5-272832 is known as a conventional refrigerating apparatus of this type. is there. The adsorption refrigerators disclosed in these publications include a refrigeration cycle for extracting heat from the refrigerant chamber and a heating cycle for extracting heat from the adsorption chamber, and the refrigerant generated from the refrigerant (for example, water) stored in the refrigerant chamber. Steam,
By adsorbing the adsorbent substance (for example, zeolite) stored in the adsorption chamber, the refrigeration operation and the heating operation using the latent heat of vaporization of the refrigerant are performed.

In order to exert the refrigerating effect by operating the adsorption type refrigerator as described above, the following steps are taken from the structure and the principle of the refrigerating action.

First, when the operation is started, the communication passage for communicating the refrigerant chamber and the adsorption chamber to move the refrigerant vapor is opened, the refrigerant is evaporated from the refrigerant chamber, and the adsorption of the refrigerant vapor by the adsorbent is started. The refrigerating capacity gradually increases and generally reaches the maximum refrigerating capacity about 3 to 10 minutes after the start of operation. After that, the refrigerating capacity gradually decreases to about 1-2.
When the adsorption of the refrigerant by the adsorbent reaches a saturated state after a lapse of time, the latent heat effect due to the evaporation of the refrigerant disappears and the refrigerating capacity becomes almost zero.

After that, the water adsorbed on the adsorbent is heated by the heater to be separated, and when this separation is completed, the initial state is restored and freezing can be started again. That is, in this type of adsorption refrigerator, cooling is repeated by desorption and adsorption of water in cycles of about 2 to 5 hours.

[0006]

On the other hand, in a cooling device using Freon gas, which is used in housing equipment and automobiles, the maximum cooling capacity corresponding to the maximum load can be exhibited from the beginning of its operation.

On the other hand, in the adsorption type refrigerator using the refrigerant such as zeolite as described above, since the heat is taken out from the refrigerant chamber, after the temperature of the entire refrigerant in the refrigerant chamber decreases, the temperature of the refrigerant chamber in the refrigerant chamber decreases. Because it is a structure that takes out heat,
As described above, the refrigerating capacity changes with time, and the maximum capacity cannot be exhibited at the start of the operation, and there is a problem that the high refrigerating capacity cannot be obtained especially at the start of the operation requiring the high refrigerating capacity. Further, complicated control is required to obtain high refrigerating capacity at the start of operation.

Further, in the conventional adsorption type refrigerator, a valve for controlling the water adsorption rate of the adsorbent is provided in the vapor passage that connects the refrigerant chamber and the adsorption chamber, and the valve is provided in the vapor passage. Since a control device for controlling the opening and closing of the valve is required, there is a problem that the device becomes complicated.

Therefore, an object of the present invention is to provide a simple structure,
It is an object of the present invention to provide a control method for an adsorption refrigerator that can apply a high refrigeration load from the beginning of operation.

[0010]

According to a first aspect of the present invention, there is provided a refrigerant chamber in which a refrigerant is stored, an adsorbent substance for adsorbing the refrigerant vapor generated from the refrigerant chamber, and the adsorbed refrigerant vapor. An adsorption chamber having an electric heater for separating the adsorbent from the adsorbent, and a vapor passage for guiding the refrigerant vapor to the refrigerant chamber and the adsorption chamber are provided. In an adsorption refrigerator having a refrigeration heat exchange cycle for exchanging, a refrigerant is adsorbed to the adsorptive substance and driving of the refrigeration heat exchange cycle is stopped,
It is characterized by comprising a pre-cooling step of lowering the temperature of the refrigerant chamber in advance before driving the refrigerating heat exchange cycle.

According to the second aspect of the present invention, the refrigerant chamber in which the refrigerant is stored and the adsorbent substance for adsorbing the refrigerant vapor generated from the refrigerant chamber are housed and the adsorbed refrigerant vapor is desorbed from the adsorbent substance. An adsorption chamber having an electric heater and a vapor passage for guiding refrigerant vapor to the refrigerant chamber and the adsorption chamber, and a refrigerating heat exchange cycle for extracting heat from the refrigerant chamber and exchanging heat. In the adsorption refrigerator having, by controlling only the temperature of the refrigerant chamber and the temperature of the adsorption chamber in a state where the vapor passage is opened,
It is characterized in that the amount of refrigerant adsorbed on the adsorbent is controlled.

According to the third aspect of the present invention, the refrigerant chamber in which the refrigerant is stored and the adsorbent substance that adsorbs the refrigerant vapor generated from the refrigerant chamber are housed and the adsorbed refrigerant vapor is desorbed from the adsorbent substance. An adsorption chamber having an electric heater and a vapor passage for guiding refrigerant vapor to the refrigerant chamber and the adsorption chamber, and a refrigerating heat exchange cycle for extracting heat from the refrigerant chamber and exchanging heat. An adsorption type refrigerator mounted on an electric vehicle, wherein a refrigerant is adsorbed to the adsorptive substance and driving of the refrigerating heat exchange cycle is stopped, and a refrigerant chamber is driven before the driving of the refrigerating heat exchange cycle. Is characterized in that it has a pre-cooling step of lowering the temperature in advance, and this pre-cooling step is performed when charging the drive battery of the electric vehicle.

[0013]

In the control method according to the first aspect, the refrigerant is adsorbed to the adsorbent in the adsorption chamber with the refrigeration heat exchange cycle stopped before driving the refrigeration heat exchange cycle.
Perform the pre-cooling process. By this pre-cooling step, the temperature of the refrigerant chamber is sufficiently lowered, and then the refrigerating heat exchange cycle is driven to take out the heat of the sufficiently cooled refrigerant chamber for heat exchange. Therefore, with a simple configuration in which the refrigerant chamber is pre-cooled before driving the refrigeration heat exchange cycle, a high refrigeration load can be obtained from the beginning of operation of the refrigeration heat exchange cycle.

In the control method according to the second aspect, since the steam passage is always open, a valve is not required in the steam passage and the structure can be simplified. Further, the amount of adsorption to the adsorbent is controlled by controlling the temperature of the refrigerant chamber and the temperature of the adsorption chamber. That is, at equilibrium, the adsorbent temperature,
Since there is a fixed relationship between the refrigerant vapor pressure and the adsorption rate of the refrigerant by the adsorbent, this is used to control the adsorption rate of the adsorbent only by controlling the temperature. Therefore, since the valve which is conventionally required is not necessary and the control is performed only on the basis of the temperatures of the refrigerant chamber and the adsorption chamber, simple and responsive control can be performed, and a high refrigeration load from the beginning of the operation. Can be obtained.

According to a third aspect of the control method of the present invention,
In the method for controlling an adsorption refrigerator having a pre-cooling step according to claim 1, the refrigerator is mounted on an electric vehicle, and the refrigeration heat exchange cycle is stopped when the drive battery of the electric vehicle is charged, in the adsorption chamber. Then, the pre-cooling step of adsorbing the refrigerant to the adsorbent is performed. Therefore, since the temperature of the refrigerant chamber is sufficiently lowered from the beginning of driving the refrigeration heat exchange cycle, it is possible to operate with a high refrigerating capacity.

[0016]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a diagram schematically showing the construction of an adsorption refrigerator apparatus according to an embodiment of the present invention, and FIGS. 2 to 6 are operations according to a control method according to an embodiment of the present invention and a conventional control method. It is a graph which shows the relationship between time and temperature, etc. Figure 7
Is a table summarizing the steps of the embodiments of the present invention.

As shown in FIG. 1, the adsorption type refrigerating apparatus 1 is
An adsorption chamber 3 containing an adsorbent substance such as zeolite and activated alumina (hereinafter referred to as “adsorbent”) and a refrigerant chamber (water tank) 5 containing a refrigerant such as water are provided. In this example, zeolite is used as the adsorbent and water is used as the refrigerant.

The surroundings of the chambers 3 and 5 are insulated by a heat insulating material or a plate material having a vacuum inside.

A vapor passage 9 is provided between the adsorption chamber 3 and the refrigerant chamber 5 so that the refrigerant vapor can move between the adsorption chamber 3 and the refrigerant chamber 5. The steam passage 9 is always open and does not have an opening / closing valve as in the conventional case. Therefore, the configuration of the entire apparatus is simple, and the control of the valve, which has been conventionally required, is not required, so that the control is simple.

Further, the adsorption chamber 3 is provided with a heater 4 for regenerating the adsorbent, which is heated when the adsorbent is regenerated. Further, the adsorption chamber 3 is embedded with a heat exchanger 6 that takes out heat generated during adsorption.

This heat exchanger 6 is provided in an external heat exchanger 11 arranged outdoors, and pumps a heat medium such as water into the pump 1
5 constitutes an external heat exchange cycle 13 circulating. By this external heat exchange cycle 13, the heat in the adsorption chamber 3 can be used for heating or the like, if necessary. The external heat exchanger 11 is provided with a fan F1 to control the heat exchange amount.

On the other hand, the refrigerant chamber 5 is provided with a heat exchanger 8 which is cooled by the latent heat of vaporization during the evaporation of the refrigerant, and the refrigerant of the heat exchanger 8 undergoes a refrigeration heat exchange cycle 21 circulated by a pump 19. I am configuring. The freezing heat exchange cycle 21
It is connected to an internal heat exchanger 17 such as a cooler of a cooling device or a refrigerator to contribute to cooling. In this embodiment, it is used as an air conditioner for an electric vehicle. Further, the refrigeration heat exchange cycle 21 is provided with an auxiliary heat exchanger 23 mainly for the purpose of discharging the condensation heat in the water tank at the time of desorption of the refrigerant, and the heat quantity of the refrigerant to be heat-exchanged is controlled. ing.
The internal heat exchanger 17 and the auxiliary heat exchanger 23 are provided with a fan F2 and a fan F3, respectively, and the heat exchange amount in each heat exchanger is controlled.

The coolant chamber 5 is provided with a water temperature sensor Tw for detecting the temperature of water as a coolant, and the adsorption chamber 3 is provided with a zeolite temperature sensor Tz for detecting the temperature of zeolite as an adsorbent. , And each is connected to the control device 7, and sends a detection signal.

The controller 7 controls the above-mentioned temperature sensor Tw,
The heater 4 and the pump 1 which are controlled based on the detection signal of Tz
5, the pump 19, as well as the fan F1, the fan F2, and the fan F3. Further, the drive signal of the mode switch 25 controls the drive of the adsorption refrigeration system 1.

Next, the operation of this embodiment will be described separately for each step. (1) Heating process In FIG. 1, the electric heater 4 heats the zeolite in the adsorption chamber 3 to about 300 ° C. During this time, the water contained in the zeolite is removed. The pump 15 of the external heat exchange cycle 13 that moves the heat of the adsorption chamber 3 is in the OFF state. On the other hand, the temperature of the refrigerant chamber 5 is kept at room temperature by circulating cold water with the pump 19 (A → B in FIGS. 2 and 3). (2) Desorption / holding process Next, the temperature of the adsorption chamber 3 is kept at about 300 ° C by the ON / OFF control of the electric heater 4 to sufficiently desorb the contained water. During this time, the temperature of the refrigerant chamber 5 is kept at room temperature in the same manner as the process of A → B (B → C in FIGS. 2 and 3). The process of A → B → C usually requires about 2 to 3 hours. (3) Pre-cooling process Next, it transfers to a pre-cooling process. As the temperature of the adsorption chamber 3 gradually decreases from about 300 ° C., the amount of adsorbed water increases, and the latent heat of water causes the temperature of the refrigerant chamber 5 to rapidly drop from room temperature. As shown in FIG. 8, the temperature of the adsorption chamber 5 and the adsorbed amount of water can maintain an equilibrium state with a constant adsorbed amount at a constant temperature. Therefore, the adsorption amount can be controlled by controlling the temperature of the zeolite,
The temperature of the refrigerant chamber 5 can be controlled by providing a valve in the vapor passage 9 that connects the adsorption chamber 3 and the refrigerant chamber 5 and keeping the adsorbent in an open communication state and controlling only the temperature of the adsorbent. During this period, the temperature of the adsorption chamber 3 is set to the value of the pump 15.
Controlled by ON-OFF.

In the case of this embodiment, the temperature of the refrigerant chamber 5 is kept at 0 ° C. for a while since it is cooled below atmospheric pressure.
Further lower to -15 ° C. In addition, the pump 19 of the refrigerant chamber 5
Is OFF and the electric heater 4 of the adsorption chamber 5 is also OFF.
(C → D in FIGS. 2 and 3).

In this pre-cooled state, it stands by in preparation for the next cooling. (4) Cooling step If cooling is started in this state, the maximum capacity is exhibited immediately after the start. After that, as the amount of water adsorbed to the adsorption chamber 3 increases, the refrigerating capacity decreases and the temperature of the adsorption chamber 5 also decreases. Changes in the refrigerating capacity during this period are shown in FIG.
On the other hand, in the conventional control method (Fig. 3), the water temperature starts to drop from room temperature, so the refrigerating capacity starts to increase from 0, and when the water temperature approaches 0 ° C, the maximum refrigerating capacity is exerted, The refrigerating capacity decreases with increasing. The change in refrigerating capacity during this period is shown in FIG.

FIG. 6 shows a comparison of the refrigerating capacity in the case of the pre-cooling process of this embodiment and in the case of the conventional non-pre-cooling process. As is clear from FIG. 6, the present invention can exhibit the maximum refrigerating capacity from the beginning, and the total refrigerating capacity (time integrated value, area under the curve in the figure) is larger in the present invention. . This is the water temperature at the start of cooling (ice temperature)
However, it can be sufficiently lowered to -15 ° C.

The above-described control of this embodiment is performed by the control device 7 of FIG. 1, and a specific control method will be described with reference to the flowchart of FIG.

Numerical values such as temperature can be changed arbitrarily. In addition, each mode can be switched with a manual switch.

First, when control is started, the routine proceeds to step S1, where it is judged whether or not it is the cooling mode. If it is the cooling mode, the routine proceeds to step S2 where the heater 4 is turned off. In step S3, it is determined whether the pre-cooling mode is set.

After the heater 4 is turned off in step S2, the fan F2 is driven in step S4 and step S5
Then, the fan F3 is stopped and the pump 19 is driven in step S6 to circulate the cold water in the external heat exchange cycle 13.
Next, in step S7, it is determined whether the room temperature TR is higher than 25 ° C, and if the temperature TR is higher than 25 ° C, step S7 is performed.
After driving the fan F1 in 8 and stopping the pump 15 in step S9, it is determined in step S10 whether or not to continue cooling.

On the other hand, if the temperature TR is 25 ° C. or lower in step S7, the pump 15 is stopped in step S11, and then it is judged in step S12 whether or not the zeolite temperature Tz is lower than 100 ° C. Stops the fan F1 in step S13. Zeolite temperature Tz is 100 ℃
If it is above, it progresses to Step S10 and it is judged whether cooling is continued.

In step S10, if cooling is continued, step S2 follows. If cooling is not continued, step S10 is executed.
Go to 3.

In step S3, it is determined whether the pre-cooling mode is set. If the pre-cooling mode is set, the process proceeds to step S14 and the heater 4 is turned off. If not in the pre-cooling mode, the process proceeds to step S15.

In step S14, the heater 4 is turned off.
After that, the fan F1 is driven in step S16, and step S
At 17, the pump 15 is driven to circulate the external heat exchange cycle, and then at step S18, the fans F2, F3 are simultaneously
Is stopped, and the pump 19 is stopped in step S19 so that the external heat exchange cycle 13 is not driven. Thereby, pre-cooling is performed.

Next, in step S20, the water temperature Tw is -15.
If the water temperature Tw is lower than -15 ° C, the pump 15 is stopped in step S21, and it is determined whether the zeolite temperature Tz is higher than 100 ° C in step S22. If it is higher than 100 ° C., the fan F1 is stopped in step S23, and it is determined in step S24 whether or not to continue precooling.

In step S20, the water temperature is Tw-15.
When the temperature is not lower than 0 ° C. or when the zeolite temperature Tz is not lower than 100 ° C., it is determined whether or not to continue the precooling in step S24 described above.

In step S15, it is determined whether the heat-up mode is set. If it is in the heat-up mode, the process proceeds to step S25. If it is not in the heat-up mode, the process proceeds to step S26 and ends.

In step S25, after driving the fan F1, the pump 15 is stopped in step S27 to stop the circulation of the external heat exchange cycle 13. Then step S2
The fan F2 is stopped at 8, and the process proceeds to step S29 to determine whether to continue the heat-up mode or not. If the heat-up mode is not continued in step S29, control ends in step S26, and if continued, step S29
In step 30, it is determined whether or not the water level in the refrigerant chamber is 80% or less. If it is not 80% or less, the process proceeds to step S31 to turn off the heater 4. If 80% or less, step S3
In step 2, it is determined whether the zeolite temperature Tz is lower than 300 ° C., and if it is low, the fan F3 is driven in step S33.
After driving the pump 19 in step S34, the heater 4 is turned on to energize, and the process returns to step S29. As a result, water is removed from the zeolite and reformed.

FIG. 10 shows an example in which the adsorption refrigerator is mounted on an electric vehicle.

The cold water in the refrigerant chamber 5 cooled by the adsorption of water in the adsorption chamber 3 is sent from the outlet 33 to the internal heat exchanger 17 through the flow path 35 via the valve 34. Here, the cold water is heat-exchanged with the air 38 at room temperature sent by the blower 37, and the cooled air 39 is sent from the air outlets (41, 42, 43, 44) into the vehicle compartment by the duct 40. The water that has undergone heat exchange in the internal heat exchanger 17 by the water supply pump 19 returns to the refrigerant chamber 5 via the flow path 26 and is cooled again. The auxiliary heat exchanger 23 is the external heat exchanger 11
, And the fans F1 and F2 are shared.

On the other hand, the pre-cooling process such as heating of the heater 4 is performed at the same time when the drive battery of the electric vehicle is charged, and the pre-cooling process is performed by the power source 28 for the adsorption refrigerator. In addition, heat radiation of hot water is performed by the external heat exchanger 11A,
Perform at 11B. The external heat exchangers 11A and 11B respectively correspond to the external heat exchanger 11 of FIG. 1, and the inflow of hot water can be switched as needed.

An external heat exchanger 11 is used as a heater during heating.

The present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the present invention.

For example, in an adsorption type refrigerator mounted on an electric vehicle, the pre-cooling step is performed when the battery for driving the electric vehicle is charged, but the starting time of the electric vehicle and the battery charging end time are predetermined. In such a case, the same effect can be obtained even if the timer is used to perform precooling 2 to 3 hours before the start of the engine.

[0048]

According to the control method of the first aspect of the present invention, since there is a pre-cooling step of cooling the refrigerant chamber in advance before driving the refrigeration heat exchange cycle, the freezing heat exchange is performed after the temperature of the refrigerant chamber is sufficiently lowered. By driving the cycle, it is possible to extract heat that is sufficiently cooled from the beginning of the operation. Therefore, a high refrigeration load can be obtained from the beginning of the operation of the refrigeration heat exchange cycle with a simple configuration of the pre-cooling step.

In the control method according to the second aspect, since the steam passage is in the open state, a valve is not required in the steam passage and the structure can be simplified. Further, since the control is performed only on the basis of the temperatures of the refrigerant chamber and the adsorption chamber, simple and responsive control can be performed, so that a high refrigeration load can be obtained from the beginning of the operation.

In the control method according to the third aspect of the present invention, since the adsorption refrigerator is mounted on the electric vehicle and the precooling step is performed when the battery for driving the electric vehicle is charged, the refrigeration heat exchange cycle is driven. At the beginning, since the temperature of the refrigerant chamber is sufficiently low, it is possible to operate with a high refrigerating capacity.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a zeolite adsorption refrigerator apparatus according to an embodiment of the present invention.

FIG. 2 is a graph showing a relationship between operating time and temperature according to the control method of the present embodiment.

FIG. 3 is a graph showing a relationship between operating time and temperature according to a conventional control method.

FIG. 4 is a graph showing the relationship between operating time and refrigerating capacity according to the control method of the present embodiment.

FIG. 5 is a graph showing a relationship between operating time and temperature according to a conventional control method.

FIG. 6 is a graph showing the relationship between operating time and refrigerating capacity according to the present embodiment and a conventional control method.

FIG. 7 is a diagram showing a process of an example of the present invention.

FIG. 8 shows the state when zeolite and water vapor are in an equilibrium state,
It is a graph of the relationship between the temperature of water and the adsorption amount.

FIG. 9 is a flowchart of a control operation according to this embodiment.

FIG. 10 is a schematic view of an adsorption refrigerator according to the present embodiment mounted on an electric vehicle.

[Explanation of symbols]

 3 Adsorption chamber 5 Refrigerant chamber 9 Steam passage

Claims (3)

[Claims] 1. An adsorption having a refrigerant chamber in which a refrigerant is stored, and an electric heater for accommodating an adsorbent substance that adsorbs the refrigerant vapor generated from the refrigerant chamber and for separating the adsorbed refrigerant vapor from the adsorbent substance. In the adsorption type refrigerator having a chamber and a vapor passage for guiding the refrigerant vapor to the refrigerant chamber and the adsorption chamber, and having a refrigerating heat exchange cycle for extracting heat from the refrigerant chamber and exchanging heat, Adsorption type characterized by having a pre-cooling step of adsorbing a refrigerant to the adsorbent and stopping driving of the refrigerating heat exchange cycle to lower the temperature of the refrigerant chamber in advance before driving the refrigerating heat exchange cycle. Refrigerator control method. 2. An adsorption having a refrigerant chamber in which a refrigerant is stored and an electric heater for accommodating an adsorbent substance for adsorbing the refrigerant vapor generated from the refrigerant chamber and for separating the adsorbed refrigerant vapor from the adsorbent substance. In the adsorption type refrigerator having a chamber and a vapor passage for guiding the refrigerant vapor to the refrigerant chamber and the adsorption chamber, and having a refrigerating heat exchange cycle for extracting heat from the refrigerant chamber and exchanging heat, A method for controlling an adsorption refrigerator, wherein the amount of refrigerant adsorbed to an adsorbent is controlled by controlling only the temperature of the refrigerant chamber and the temperature of the adsorption chamber with the vapor passage opened. 3. An adsorption having a refrigerant chamber in which a refrigerant is stored and an electric heater for accommodating an adsorbent substance for adsorbing the refrigerant vapor generated from the refrigerant chamber and for separating the adsorbed refrigerant vapor from the adsorbent substance. Chamber and a vapor passage for mutually guiding the refrigerant vapor to the refrigerant chamber and the adsorption chamber, and the refrigerant chamber has a refrigeration heat exchange cycle for extracting heat and exchanging heat, and mounted on an electric vehicle. A pre-cooling system for adsorbing a refrigerant to the adsorptive substance and stopping driving of the refrigeration heat exchange cycle to lower the temperature of the refrigerant chamber before driving the refrigeration heat exchange cycle. Have a process,
This pre-cooling step is performed when charging a drive battery for an electric vehicle, wherein the adsorption refrigerating machine for an electric vehicle is controlled.