JP6898762B2 - Heat storage system and heat storage system operation method - Google Patents

Description

The present application relates to a heat storage system and a method of operating the heat storage system.

Patent Document 1 describes a catalyst warm-up device in which a chemical reaction heat storage device is provided around a catalyst ceramic portion that purifies exhaust gas and water is supplied to generate heat of a heat storage substance when it is cold. In this catalyst warm-up device, a reversible reaction is caused after warming up, and the water after the reaction is discharged to the outside as water vapor.

JP-A-59-208118

In a heat storage system in which a reaction medium vaporized by an evaporator is adsorbed by a heat storage device to store heat, if the pressure difference between the evaporator and the heat storage device is large, the liquid phase reaction medium moves from the evaporator to the heat storage device. A phenomenon, so-called liquid splattering, may occur. When the liquid phase reaction medium is supplied to the heat storage device, the amount of heat stored in the heat storage device may decrease.

In consideration of the above facts, it is an object of the present invention to suppress a decrease in the amount of heat stored in the heat storage due to liquid splashing from the evaporator to the heat storage.

In the first aspect, an evaporator in which the reaction medium is vaporized, a heat storage device that stores heat by adsorption or chemical reaction of the reaction medium vaporized by the evaporator, and a reaction medium that connects the evaporator and the heat storage device. It has a pipe, an on-off valve for opening and closing the reaction medium pipe, and a relaxation member for alleviating a time change of a pressure difference between the evaporator and the heat storage device in the opened state of the on-off valve.

In this heat storage system, when the on-off valve is opened, the reaction medium evaporated by the evaporator moves to the heat storage through the reaction medium piping. In the heat storage device, heat is stored by adsorption of the reaction medium or a chemical reaction.

Since the evaporator has a higher pressure than the heat storage device, a pressure difference occurs between the evaporator and the heat storage device when the on-off valve is open. Since the relaxation member relaxes the time change of the pressure difference, it is possible to suppress the phenomenon that the reaction medium of the liquid phase moves from the evaporator to the heat storage device, that is, so-called liquid skipping. By suppressing the liquid from spilling onto the heat storage device, it is possible to suppress a decrease in the amount of heat stored in the heat storage device.

In the second aspect, in the first aspect, the relaxation member bypasses the on-off valve and has a bypass pipe having a larger pressure loss than the reaction medium pipe, a bypass on-off valve that opens and closes the bypass pipe, and the opening / closing. A control device for controlling the opening and closing of the valve and the bypass on-off valve is included.

When the control device closes the on-off valve and opens the bypass on-off valve, the pressure loss of the bypass on-off valve is larger than the pressure loss of the reaction medium piping, so that the reaction medium moves rapidly from the evaporator to the regenerator. Is suppressed. As a result, the time change of the pressure difference between the evaporator and the regenerator is alleviated, and the reaction medium gradually moves from the evaporator to the regenerator.

In the third aspect, in the first aspect, the relaxation member includes a control device that controls the opening and closing of the on-off valve to be repeated at a predetermined time.

The on-off valve is repeatedly opened and closed at a predetermined time by the control device. Even if the pressure difference between the evaporator and the heat storage device is large, the reaction medium moves from the evaporator to the heat storage device in a plurality of times within a predetermined time. That is, within a predetermined time, the rapid movement of the reaction medium from the evaporator to the heat storage device is suppressed. As a result, the time change of the pressure difference between the evaporator and the regenerator is alleviated, and the reaction medium gradually moves from the evaporator to the regenerator.

In the fourth aspect, in the first aspect, the on-off valve is provided on the first on-off valve provided in the reaction medium pipe and on the heat storage side of the reaction medium pipe with respect to the first on-off valve. The relaxation member includes the first on-off valve and the second on-off valve, including an evaporator and a second on-off valve that forms a buffer portion having a volume smaller than that of the heat storage device between the first on-off valve and the first on-off valve. It includes a control device that alternately repeats opening one valve and closing the other valve.

The control device alternately repeats opening one of the first on-off valve and the second on-off valve and closing the other. The reaction medium of the evaporator is temporarily stored in the buffer section and then moved to the regenerator. Even if the pressure difference between the evaporator and the heat storage device is large, the reaction medium moves from the evaporator to the heat storage device in a plurality of times within a predetermined time. That is, the rapid movement of the reaction medium from the evaporator to the heat storage device is suppressed. As a result, the time change of the pressure difference between the evaporator and the regenerator is alleviated, and the reaction medium gradually moves from the evaporator to the regenerator.

In the fifth aspect, in any one of the second to fourth aspects, a first pressure sensor for detecting the pressure of the evaporator and a second pressure sensor for detecting the pressure of the heat storage device are provided. The control device controls the relaxation member based on the pressure of the evaporator detected by the first pressure sensor and the pressure of the regenerator detected by the second pressure sensor.

Since the control of the relaxation member by the control device is based on the pressure of the evaporator detected by the first pressure sensor and the pressure of the heat storage device detected by the second pressure sensor, it is compared with the configuration in which the control is not based on these pressures. Therefore, more accurate control is possible.

In the sixth aspect, in the fifth aspect, the control device stops the operation of the relaxation member when the ratio of the pressure of the evaporator to the pressure of the heat storage device is equal to or less than a predetermined threshold value.

When the pressure ratio is below the threshold value, the relaxation member is stopped by the control device. When the relaxation member is stopped, the pressure loss from the evaporator to the regenerator is smaller than when it is operating, so the reaction medium can be moved from the evaporator to the regenerator in a short time. it can.

In the seventh aspect, in any one of the first to sixth aspects, the reaction medium is an antifreeze refrigerant.

The "antifreeze refrigerant" referred to here is, for example, a solution in which a solute for lowering the freezing point is dissolved in a solvent such as water. Since the antifreeze solution has a lower freezing point than the solvent-only reaction medium, the heat storage system can be operated even at a lower temperature.

If the solute of the antifreeze refrigerant is adsorbed on the heat storage device, the heat storage capacity of the heat storage device may decrease. The relaxation member alleviates the time change of the pressure difference between the evaporator and the heat storage device, and suppresses the liquid jump, so that the solute of the antifreeze refrigerant is not adsorbed by the heat storage device, and the heat storage capacity of the heat storage device is reduced. Can be suppressed.

In the eighth aspect, in any one of the first to seventh aspects, the heat storage device is thermally connected to an external heat source, and the reaction medium is adsorbed or desorbed by an adsorbent or the reaction medium is a chemical heat storage agent. Heat storage and heat dissipation are possible by the chemical reaction of.

Therefore, it is possible to dissipate the heat generated by the adsorption of the reaction medium by the adsorbent or the chemical reaction of the reaction medium by the chemical heat storage agent to an external heat source. Further, it is possible to desorb the reaction medium from the adsorbent by receiving heat from an external heat source, or to cause a reverse reaction of a chemical reaction in a chemical heat storage agent.

In the ninth aspect, the reaction medium vaporized by the evaporator is moved to the heat storage device in the open state of the on-off valve of the reaction medium pipe to store heat by adsorption or chemical reaction, and the evaporation is carried out in the open state of the on-off valve. The reaction medium is moved to the heat storage device by relaxing the time change of the pressure change between the device and the heat storage device.

Since the evaporator has a higher pressure than the heat storage device, a pressure difference occurs between the evaporator and the heat storage device when the on-off valve is open. By relaxing the time change of this pressure difference, it is possible to suppress the phenomenon that the reaction medium of the liquid phase moves from the evaporator to the heat storage device, that is, so-called liquid skipping. By suppressing the liquid spill to the heat storage device, the energy can be reduced to vaporize the reaction medium in the heat storage device, and the decrease in the heat storage amount of the heat storage device can be suppressed.

In the tenth aspect, in the ninth aspect, when the pressure difference between the pressure of the evaporator and the pressure of the heat storage device is equal to or less than a predetermined pressure threshold value, the time change of the pressure change is not relaxed.

When the differential pressure is equal to or lower than the pressure threshold value, the time change of the pressure difference between the evaporator and the regenerator is not relaxed, so that the reaction medium can be moved from the evaporator to the regenerator in a short time.

Since the present invention has the above configuration, it is possible to suppress a decrease in the amount of heat stored in the heat storage due to liquid splattering from the evaporator to the heat storage.

FIG. 1 is a diagram showing a configuration of a heat storage system according to the first embodiment. FIG. 2 is a flowchart showing an example of an operation method in the heat storage system of the first embodiment. FIG. 3 is a graph showing the time change of the pressure of the evaporator and the heat storage device in the heat storage system of the first embodiment. FIG. 4 is a diagram showing a configuration of a heat storage system of a comparative example. FIG. 5 is a graph showing the time change of the pressure of the evaporator and the heat storage device in the heat storage system of the comparative example. FIG. 6 is a graph showing the relationship between the liquid skip ratio and the effective heat storage amount ratio. FIG. 7 is a diagram showing the configuration of the heat storage system of the second embodiment. FIG. 8 is a flowchart showing an example of an operation method in the heat storage system of the second embodiment. FIG. 9 is a graph showing the time change of the pressure of the evaporator and the heat storage device in the heat storage system of the second embodiment. FIG. 10 is a diagram showing the configuration of the heat storage system of the third embodiment. FIG. 11 is a flowchart showing an example of an operation method in the heat storage system of the third embodiment. FIG. 12 is a graph showing the time change of the pressure of the evaporator and the heat storage device in the heat storage system of the third embodiment. FIG. 13 is a graph showing the relationship between the number of cycles of the heat storage system and the effective heat storage amount ratio.

As shown in FIG. 1, the heat storage system 112 of the first embodiment includes an evaporator 114 and a heat storage device 116. The evaporator 114 and the heat storage device 116 are connected by a reaction medium pipe 118.

In the evaporator 114, cold heat is generated by evaporating the reaction medium inside the evaporator 114. It is possible to cool a cooling target (not shown) by this cooling heat.

In the present embodiment, the heat storage device 116 contains an adsorbent inside, and the adsorbent adsorbs the reaction medium of the gas phase. Then, the heat generated during adsorption is stored. As the adsorbent, an appropriate material can be selected depending on the combination with the reaction medium. For example, when water or an aqueous ethylene glycol solution described later is used as the reaction medium, 13X zeolite can be mentioned as an example of the adsorbent, but the reaction medium is not limited to this.

An external heat source 120 is thermally connected to the heat storage device 116, and it substantially acts as a heat exchanger. The heat stored in the heat storage device 116 can be dissipated to the external heat source 120. Further, the heat storage device 116 can be regenerated by desorbing the reaction medium from the adsorbent by the heat received from the external heat source 120. As the external heat source 120, the member or portion that receives heat from the heat storage device 116 and the member or portion that dissipates heat to the heat storage device 116 may be separate bodies.

In the present embodiment, the evaporator 114 also serves as a condenser. The vapor phase reaction medium desorbed from the heat storage device 116 is returned to the evaporator 114, and is liquefied by the evaporator 114 functioning as a condenser. Of course, a configuration having a condenser separate from the evaporator 114 may be used.

An example of the reaction medium of the present embodiment is an ethylene glycol aqueous solution in which ethylene glycol is dissolved in water as a solvent in an amount of about 30% by weight as a solute. Ethylene glycol is an example of a solute that lowers the freezing point of a solvent. As a result, the reaction medium of the present embodiment acts as an antifreeze refrigerant having a lower freezing point than pure water.

The reaction medium pipe 118 is provided with an on-off valve 122. The opening and closing of the on-off valve 122 is controlled by the control device 128. In the valve open state of the on-off valve 122, the reaction medium can be moved from the evaporator 114 to the heat storage device 116, but in the valve closed state, the reaction medium cannot be moved.

In the first embodiment, the reaction medium pipe 118 is provided with a bypass pipe 124 that bypasses the on-off valve 122. Hereinafter, the path through which the reaction medium moves from the evaporator 114 to the heat storage device 116 without passing through the bypass pipe 124 is referred to as a direct path RD, and the path through the bypass pipe 124 is referred to as a bypass path RB. The pressure loss of the bypass pipe 124 is set to be higher than that when the reaction medium does not pass through the bypass pipe 124. Therefore, the pressure loss ΔPB of the bypass path RB is larger than the pressure loss ΔPD of the direct path RD.

The bypass pipe 124 is provided with a bypass on-off valve 126. The opening and closing of the bypass on-off valve 126 is controlled by the control device 128. In the first embodiment, as an example of the relaxation member 134, the bypass pipe 124 and the bypass on-off valve 126 are included.

The heat storage system 112 includes a first pressure sensor 130 that detects the pressure of the evaporator 114 and a second pressure sensor 132 that detects the pressure of the heat storage device 116. The pressure value detected by these pressure sensors is sent to the control device 128. The control device 128 controls the opening and closing of the on-off valve 122 and the bypass on-off valve 126 based on the value of the pressure sent from the pressure sensor.

Next, the operation and operation method of the heat storage system 112 of the present embodiment will be described while comparing with the heat storage system 12 of the comparative example shown in FIG.

The heat storage system 12 of the comparative example has an evaporator 114, a heat storage device 116, and a reaction medium pipe 118 similar to the heat storage system 112 of the first embodiment. However, the relaxation member, that is, the bypass pipe for bypassing the on-off valve 122 of the reaction medium pipe 118 is not provided, and the bypass on-off valve is not provided either. Then, in the heat storage system 12 of the comparative example, as the opening / closing control of the on-off valve 122 by the control device 128, for example, the control that repeatedly opens and closes the on-off valve 122 in a short time is not performed, and the valve is opened or opened for a certain period of time. Control to maintain the valve closed state.

In the heat storage system 12 of the comparative example, when the reaction medium is evaporated by the evaporator 114 in a state where the control device 128 closes the on-off valve 122, the pressure P1 of the evaporator 114 becomes high.

FIG. 5 shows the time change of the pressure P1 of the evaporator 114 and the pressure P2 of the heat storage device 116 in the heat storage system 12 of the comparative example. The pressure P2 of the heat storage device 116 is relatively low with respect to the pressure P1 of the evaporator 114. That is, in the heat storage system 12, the value of the differential pressure between the pressure P1 of the evaporator 114 and the pressure P2 of the heat storage device 116 becomes large before the latent heat of the reaction medium is radiated from the evaporator 114 to the heat storage device 116. (P1-P2 = PA-PB).

It is assumed that the control device 128 opens the on-off valve 122 in this state. In FIG. 5, the time T1 is the time when the on-off valve 122 is opened. By opening the on-off valve 122, the evaporator 114 and the heat storage device 116 are communicated with each other. Then, the pressure P1 of the evaporator 114 drops sharply in a short time, and the pressure P2 of the heat storage device 116 rises sharply in a short time. As a result, a "liquid jump" may occur in which a part of the reaction medium in the evaporator 114 moves to the heat storage device 116 in a liquid phase state.

Generally, when the liquid is supplied to the heat storage device and adheres to the adsorbent, the volume at which the adsorbent can adsorb the reaction medium of the gas phase becomes small. Then, a large amount of energy is required to vaporize the adhered liquid and adsorb it with the adsorbent. That is, the substantial amount of heat stored in the heat storage device 116 becomes small.

FIG. 6 shows an example of the relationship between the liquid skip ratio and the effective heat storage amount ratio of the heat storage device 116. The “liquid skip ratio” on the horizontal axis of this graph is the ratio (percentage) of the liquid splashed reaction medium to the total amount of the reaction medium in the evaporator 114. Further, the "effective heat storage amount ratio" on the vertical axis of this graph is the ratio of the actual heat storage amount after liquid splashing to the total heat storage amount of the heat storage device 116. The total heat storage amount is the amount of heat storage when the adsorbent of the heat storage device 116 does not adsorb the reaction medium at all and adsorbs it to the limit.

As can be seen from the graph of FIG. 6, the higher the liquid jump ratio, the lower the effective heat storage rate. In the heat storage system 12 of the comparative example, liquid skipping may actually occur, which may reduce the effective heat storage amount rate.

On the other hand, in the heat storage system 112 of the first embodiment, the relaxation member 134 is operated by controlling the flow shown in FIG. 2, and the liquid splash is suppressed. In the control of the first embodiment, both the on-off valve 122 and the bypass on-off valve 126 are closed as an initial state.

In this control flow, first, in step S102, the control device 128 acquires the pressure P1 of the evaporator 114 from the first pressure sensor 130, and further acquires the pressure P2 of the heat storage device 116 from the second pressure sensor 132.

In step S104, it is determined whether or not the ratio of these pressures P1 and P2 (pressure ratio P1 / P2) is larger than the predetermined threshold value C1. The threshold value C1 is a value at which liquid splash may occur when the on-off valve 122 is opened while the pressure ratio P1 / P2 exceeds the threshold value C1, and for example, the threshold value C1 = 5. Instead of the pressure ratio P1 / P2, the pressure difference P1-P2 may be used, and the determination in step S104 may be performed based on whether or not this pressure difference is larger than a predetermined pressure threshold value. When the pressure ratio P1 / P2 is used, the absolute pressure is used for the pressures P1 and P2. On the other hand, when the pressure difference P1-P2 is used, the pressures P1 and P2 may be absolute pressure or gauge pressure (relative pressure).

If it is determined in step S104 that the pressure ratio P1 / P2 is equal to or less than the threshold value C1, the process proceeds to step S106. In step S106, the control device 128 opens the on-off valve 122 (always in a valve-opened state), but since the pressure ratio P1 / P2 is equal to or less than the threshold value C1, liquid splash does not occur.

If it is determined in step S106 that the pressure ratio P1 / P2 exceeds the threshold value C1, the process proceeds to step S108. In step S108, the bypass on-off valve 126 is opened. Then, the process returns to step S102. After that, the on-off valve 122 is closed and the bypass on-off valve 126 is maintained in the opened state until the pressure ratio P1 / P2 becomes equal to or less than the threshold value C1.

FIG. 3 shows the time change of the pressure P1 (the pressure in the initial state is PA) of the evaporator 114 and the pressure P2 (the pressure in the initial state is PB) of the heat storage device 116 in the heat storage system 112 of the first embodiment. There is.

The pressure loss of the bypass path RB is larger than the pressure loss of the direct path RD. Therefore, as can be seen from FIG. 3, the drop in pressure P1 from the time T1 when the bypass on-off valve 126 is opened to the time T2 when the on-off valve 122 is always opened in the first embodiment is larger than that in the comparative example. It is gradual. Similarly, in the first embodiment, the increase in pressure P2 from time T1 to time T2 is also slower than in the comparative example. Then, in the first embodiment, the time change of the differential pressure P1-P2 at this time is also gentler than that of the comparative example.

As described above, in the first embodiment, in the initial stage when the reaction medium moves from the evaporator 114 to the heat storage device 116 (the initial stage of heat dissipation start), the time change of the differential pressure between the evaporator 114 and the heat storage device 116 is made gentle. Therefore, liquid splash can be suppressed. Since the liquid skipping is suppressed, the liquid skipping ratio is 0%, and from the graph of FIG. 6, it can be seen that the effective heat storage amount rate is 100% in the heat storage system 112 of the first embodiment.

In particular, in the heat storage system 112 of the first embodiment, since the on-off valve 122 and the bypass on-off valve 126 are not repeatedly opened and closed in a short time, the control is easy and the mitigation member 134 is inexpensive. Can be activated.

Next, the second embodiment will be described. In the second embodiment, the same elements, members, and the like as in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 7, in the heat storage system 212 of the second embodiment, the bypass pipe 124 and the bypass on-off valve 126 (see FIG. 1) of the first embodiment are not provided. Then, the on-off valve 122 is controlled by the control device 128 so as to repeat opening and closing in a short time within a predetermined time. That is, the relaxation member 134 of the second embodiment has a configuration including control for repeatedly opening and closing the on-off valve 122 within a predetermined time by the control device 128.

In the heat storage system 212 of the second embodiment, liquid splattering is suppressed by the control shown in FIG.

In this control flow, in step S202, the control device 128 acquires the pressure P1 and the pressure P2, and in step S204, it is determined whether or not the pressure ratio P1 / P2 is larger than the predetermined threshold value C1. Then, when it is determined in step S204 that the pressure ratio P1 / P2 is equal to or less than the threshold value C1, the process proceeds to step S206. In step S206, the control device 128 is always in the valve open state without repeating the opening and closing of the on-off valve 122 in a short time. Up to this point, the same as steps S102 to S106 of the control flow in the heat storage system 112 of the first embodiment.

In the second embodiment, when it is determined in step S204 that the pressure ratio P1 / P2 exceeds the threshold value C1, the process proceeds to step S208. In step S208, the control device 128 repeatedly opens and closes the on-off valve 122 in a short time. Such control is sometimes referred to as duty ratio control.

Specifically, as shown in FIG. 9, from time T1 to time T2, the on-off valve 122 is opened between the time ΔTH2 and the on-off valve 122 is closed between the time ΔTT2. Alternate with the state of being. With the on-off valve 122 opened, the pressure P1 drops in a short time, but since the valve opening time ΔTH2 is short, the amount of pressure drop is small. Similarly, the pressure P2 rises in a short time when the on-off valve 122 is opened, but the pressure rise amount is small because the valve opening time ΔTH2 is short. When the on-off valve 122 is closed, the pressure P1 hardly changes, and the pressure P2 hardly changes either.

In step S208, the on-off valve 122 is opened and closed a predetermined number of times, and then the process returns to step S202. Alternatively, the process may return to step S202 while opening and closing the on-off valve 122.

As described above, in the second embodiment, since the on-off valve 122 is repeatedly opened and closed, evaporation is performed in a plurality of times from the time T1 when the bypass on-off valve 122 is opened to the time T2 when the on-off valve 122 is always opened. The reaction medium moves from the vessel 114 to the regenerator 116. As can be seen from FIG. 9, the time change of the drop of the pressure P1 from the time T1 to the time T2 is gradual as compared with the comparative example. Similarly, the time change of the rise of the pressure P2 from the time T1 to the time T2 is also gradual as compared with the comparative example. The time average change of the differential pressures P1-P2 is also gradual. That is, also in the second embodiment, in the initial stage when the reaction medium moves from the evaporator 114 to the heat storage device 116 (the initial stage of heat dissipation start), the time change of the differential pressure between the evaporator 114 and the heat storage device 116 is made gentle. , Liquid splash can be suppressed.

In particular, in the heat storage system 212 of the second embodiment, since it is not necessary to provide a bypass path for the on-off valve 122 or a bypass on-off valve for opening and closing the bypass path, the number of parts is small.

Next, the third embodiment will be described. In the third embodiment, the same elements, members, and the like as those in the first embodiment or the second embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 10, in the heat storage system 312 of the third embodiment, the bypass pipe 124 and the bypass on-off valve 126 (see FIG. 1) of the first embodiment are not provided. The reaction medium pipe 118 is provided with a first on-off valve 122A located close to the evaporator 114 and a second on-off valve 122B located close to the heat storage device 116 as on-off valves 122.

The opening and closing of the first on-off valve 122A and the opening and closing of the second on-off valve 122B are controlled by the control device 128.

In the reaction medium pipe 118, the portion between the first on-off valve 122A and the second on-off valve 122B is a buffer portion 314 having a predetermined volume. The volume of the buffer unit 314 is smaller than the volume of the evaporator 114 and the volume of the heat storage device 116.

In the heat storage system 312 of the third embodiment, liquid splashing is suppressed by the control shown in FIG. That is, the relaxation member 134 of the third embodiment has a configuration including a control in which the control device 128 repeatedly opens and closes the first on-off valve 122A and the second on-off valve 122B within a predetermined time.

In this control flow, in step S302, the control device 128 acquires the pressure P1 and the pressure P2, and in step S304, it is determined whether or not the pressure ratio P1 / P2 is larger than the predetermined threshold value C1. Then, when it is determined in step S304 that the pressure ratio P1 / P2 is equal to or less than the threshold value C1, the process proceeds to step S306. Up to this point, the same as steps S102 to S106 of the control flow in the heat storage system 112 of the first embodiment. However, in step S306, both the first on-off valve 122A and the second on-off valve 122B are always opened.

In the third embodiment, when it is determined in step S304 that the pressure ratio P1 / P2 exceeds the threshold value C1, the process proceeds to step S308. In step S308, in the control device 128, the first on-off valve 122A is closed and the second on-off valve 122B is opened (hereinafter referred to as "first on-off state"), and the first on-off valve 122A is opened. The state in which the second on-off valve 122B is closed (hereinafter referred to as "second on-off state") is repeated in a short time.

Specifically, as shown in FIG. 12, from time T1 to time T2, the first open / closed state during the time ΔTH3 and the second open / closed state during the time ΔTT3 are alternately performed. In the first open / closed state, the heat storage device 116 and the buffer unit 314 are communicated with each other, and the volume of the buffer unit 314 is smaller than the volume of the heat storage device 116. The pressure P3 of the part 314 is greatly reduced. Further, in the first open / closed state, the pressure P1 of the evaporator 114 is constant.

On the other hand, in the second open / closed state, the evaporator 114 and the buffer portion 314 are communicated with each other, and the volume of the buffer portion 314 is smaller than the volume of the evaporator 114, so that the pressure P1 of the evaporator 114 is slightly lowered. At the same time, the pressure P3 of the buffer unit 314 rises significantly. However, the pressure P3 of the buffer unit 314 at this time is a value lower than the pressure PA in the initial state of the evaporator 114.

After realizing the first open / closed state and the second open / closed state a predetermined number of times in step S308, the process returns to step S302. Alternatively, the process may return to step S302 while repeating the first opening / closing state and the second opening / closing state.

In this way, in the third embodiment, the reaction medium is temporarily stored in the buffer unit 314 by repeating the first open / closed state and the second open / closed state, and then the stored reaction medium is stored in the heat storage device. The operation of moving to 116 is repeated a plurality of times. As can be seen from FIG. 12, the time change of the drop of the pressure P1 from the time T1 to the time T2 is gradual as compared with the comparative example. Similarly, the time change of the rise of the pressure P2 from the time T1 to the time T2 is also gradual as compared with the comparative example. The time average change of the differential pressures P1-P2 is also gradual. That is, also in the third embodiment, in the initial stage when the reaction medium moves from the evaporator 114 to the heat storage device 116 (the initial stage of heat dissipation start), the time change of the differential pressure between the evaporator 114 and the heat storage device 116 is made gentle. , Liquid splash can be suppressed.

In particular, in the third embodiment, a plurality of (two in the example of FIG. 10) on-off valves 122 are provided in series with the reaction medium pipe 118, and when one of the on-off valves 122 is opened, the other is opened and closed. The valve 122 is closed. As a result, a direct movement path of the reaction medium from the evaporator 114 to the heat storage device 116 does not occur, so that liquid splattering can be suppressed more reliably.

In the heat storage system of each of the above embodiments, the liquid splash from the evaporator 114 to the heat storage device 116 is suppressed by the relaxation member 134, so that even if the pressure loss of the reaction medium pipe 118 is reduced, the heat storage device from the evaporator 114 No liquid splashing to 116 occurs. By reducing the pressure loss of the reaction medium pipe 118, it is possible to increase the amount of movement per unit time when the reaction medium moves from the evaporator 114 to the heat storage device 116.

In each of the above embodiments, an external heat source 120 is connected to the heat storage device 116. The heat of the heat storage device 116 can be dissipated to the external heat source 120. Further, the reaction medium can be desorbed from the adsorbent of the heat storage device 116 by receiving the heat of the external heat source 120, and the heat storage device 116 can be regenerated.

In each of the above embodiments, in the initial stage when the reaction medium moves from the evaporator 114 to the heat storage device 116 (initial stage of heat dissipation start), the liquid splash is suppressed without being based on the pressure ratio P1 / P2 or the pressure difference P1-P2. Control may be performed. In this case, this control is terminated based on the pressure ratio P1 / P2 or the pressure difference P1-P2.

The heat storage device 116 may be a heat storage device that stores heat by a chemical reaction of the reaction medium, in addition to the structure that adsorbs the reaction medium.

The reaction medium may be water, for example, as long as it is vaporized by the evaporator 114 and moved to the heat storage device 116, and the heat storage device 116 has an action of storing heat by the above-mentioned adsorption or chemical reaction.

Further, the solution in which the solute for lowering the freezing point is dissolved in water is an antifreeze solution that does not solidify even below the freezing point. By using such an antifreeze solution as a reaction medium, the reaction medium does not solidify even below the freezing point, so that the heat storage system can be operated below the freezing point. For example, an aqueous solution containing water as a solvent and ethylene glycol as a solute can be used as a reaction medium. In this case, the above-mentioned zeolite can be used as the adsorbent for the heat storage device 116. Examples of the freezing point depression agent include organic solvents (ethylene glycol is an example), inorganic salts, organic salts and the like.

In a solution using a freezing point depression agent as a solute, if the solution is supplied to the heat storage device 116 in a liquid phase state, the freezing point depression agent may be adsorbed by the adsorbent. Since the reaction medium of the gas phase cannot be adsorbed at the portion where the freezing point depression agent is adsorbed in the adsorbent, the adsorption characteristics of the adsorbent deteriorate. In particular, some freezing point depression agents such as the above-mentioned ethylene glycol are difficult to be desorbed from the adsorbent by heat from an external heat source used in a general heat storage system 112. Therefore, every time the operation of the heat storage system 112 is repeated, the freezing point depression agent is accumulated and adsorbed on the adsorbent.

FIG. 13 shows the relationship between the number of operations of the heat storage system 112 and the effective heat storage rate when the ethylene glycol aqueous solution is repeatedly skipped in the heat storage system. When liquid splashes occur, the effective heat storage rate decreases with each operation even if the ratio is low. On the other hand, in the heat storage systems 112, 212, and 312 of each of the above-described embodiments, the liquid splash does not occur in the first place, so that the effective heat storage amount rate does not decrease even if the operation is repeated.

112 Heat storage system 114 Evaporator 116 Heat storage 118 Reaction medium piping 120 External heat source 122 On-off valve 122A First on-off valve 122B Second on-off valve 124 Bypass piping 126 Bypass on-off valve 128 Control device 130 First pressure sensor 132 Second pressure sensor 134 Mitigation member 212 Heat storage system 312 Heat storage system

Claims (10)

An evaporator in which the reaction medium is vaporized, and
A heat storage device that stores heat by adsorption or chemical reaction of the reaction medium vaporized by the evaporator.
A reaction medium pipe connecting the evaporator and the heat storage device, and
An on-off valve that opens and closes the reaction medium piping,
The first pressure sensor that detects the pressure of the evaporator and
A second pressure sensor that detects the pressure of the heat storage device and
A relaxation member that alleviates the time change of the pressure difference between the evaporator and the heat storage device in the opened state of the on-off valve, and
Have,
The relaxation member
A heat storage system including a control device that controls the relaxation member based on the pressure of the evaporator detected by the first pressure sensor and the pressure of the heat storage device detected by the second pressure sensor. An evaporator in which the reaction medium is vaporized, and
A heat storage device that stores heat by adsorption or chemical reaction of the reaction medium vaporized by the evaporator.
A reaction medium pipe connecting the evaporator and the heat storage device, and
An on-off valve that opens and closes the reaction medium piping,
A relaxation member that alleviates the time change of the pressure difference between the evaporator and the heat storage device in the opened state of the on-off valve, and
Have,
The relaxation member
A bypass pipe that bypasses the on-off valve and has a larger pressure loss than the reaction medium pipe,
A bypass on-off valve that opens and closes the bypass pipe,
A control device that controls the opening and closing of the on-off valve and the bypass on-off valve, and
Including heat storage system. An evaporator in which the reaction medium is vaporized, and
A heat storage device that stores heat by adsorption or chemical reaction of the reaction medium vaporized by the evaporator.
A reaction medium pipe connecting the evaporator and the heat storage device, and
An on-off valve that opens and closes the reaction medium piping,
A relaxation member that alleviates the time change of the pressure difference between the evaporator and the heat storage device in the opened state of the on-off valve, and
Have,
The on-off valve
The first on-off valve provided in the reaction medium pipe and
In the reaction medium piping, a second on-off valve provided on the heat storage side of the first on-off valve and a buffer portion having a volume smaller than that of the evaporator and the heat storage valve is formed between the first on-off valve and the first on-off valve. ,
Including
The relaxation member
A heat storage system including a control device that alternately repeats opening one of the first on-off valve and the second on-off valve and closing the other valve. The first pressure sensor that detects the pressure of the evaporator and
A second pressure sensor that detects the pressure of the heat storage device and
With
The second or third aspect, wherein the control device controls the relaxation member based on the pressure of the evaporator detected by the first pressure sensor and the pressure of the regenerator detected by the second pressure sensor. Heat storage system. The heat storage system according to claim 1, wherein the control device controls to repeatedly open and close the on-off valve at a predetermined time. The heat storage system according to claim 1, 4, or 5 , wherein the control device stops the operation of the relaxation member when the ratio of the pressure of the evaporator to the pressure of the heat storage device is equal to or less than a predetermined threshold value. The heat storage system according to any one of claims 1 to 6, wherein the reaction medium is an antifreeze refrigerant. The heat storage device is thermally connected to an external heat source, and heat can be stored and dissipated by the adsorption / desorption of the reaction medium by an adsorbent or the chemical reaction of the reaction medium by a chemical heat storage agent. The heat storage system according to any one item. The reaction medium vaporized by the evaporator is moved to the heat storage device with the on-off valve of the reaction medium piping open, and heat is stored by adsorption or chemical reaction.
Based on the pressure of the evaporator and the pressure of the heat storage device, the reaction medium is moved to the heat storage device by relaxing the time change of the pressure difference between the evaporator and the heat storage device in the opened state of the on-off valve. How to operate the heat storage system. The reaction medium vaporized by the evaporator is moved to the heat storage device with the on-off valve of the reaction medium piping open, and heat is stored by adsorption or chemical reaction.
With the on-off valve open, the reaction medium is moved to the heat storage by relaxing the time change of the pressure difference between the evaporator and the heat storage.
A heat storage system operating method in which the time change of the pressure difference is not relaxed when the pressure difference between the pressure of the evaporator and the pressure of the heat storage device is equal to or less than a predetermined pressure threshold value.

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