JP2016090171A - Chemical heat storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely detect leakage of NHfrom an adsorber.SOLUTION: A chemical heat storage device 10 includes a reactor 11, an adsorber 12, a supply pipe 15 connecting the reactor 11 and the adsorber 12, a solenoid valve 16 disposed in the supply pipe 15 and opening and closing a flow channel of NH, a first storage amount calculating portion 22 for calculating an NHstorage amount A existing in the adsorber 12 when the solenoid valve 16 is closed after recovering NHfrom the reactor 11 into the adsorber 12, a second storage amount calculating portion 23 for calculating an NHstorage amount B existing in the adsorber 12 after the lapse of a prescribed time from the closing of the solenoid valve 16, and a leakage determination portion 24 for determining whether NHleaks from the adsorber 12 or not on the basis of the NHstorage amounts A, B. The leakage determination portion 24 calculates the difference between the NHstorage amount A and the NHstorage amount B, and determines the leakage of NHfrom the adsorber 12 in a case when a value of the difference becomes more than a prescribed value.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a chemical heat storage device.

As a conventional chemical heat storage device, for example, a device described in Patent Document 1 is known. The chemical heat storage device described in Patent Document 1 uses the heat generated by the chemical reaction between the reaction material and the reaction medium (NH ₃ ) when the temperature of the exhaust gas discharged from the internal combustion engine is low, and the exhaust system of the internal combustion engine of the vehicle The heat exchanger provided in the heat exchanger is heated, and the exhaust gas passing through the heat exchanger is raised to a temperature (activation temperature) at which the downstream exhaust gas purification catalyst exhibits the purification capability, and the temperature of the internal combustion engine sufficiently rises Is applied to an exhaust gas purification system in which the reaction medium is desorbed from the reaction material by applying heat of the exhaust gas to the reaction material via a heat exchanger, and the desorbed reaction medium is recovered again. .

In such a chemical heat storage device, when the temperature of the exhaust gas discharged from the internal combustion engine is lower than a predetermined temperature, NH ₃ stored in the storage is supplied to the reactor through the supply pipe, and the supplied NH ₃ and the reactor are supplied. This reacts with the reaction material to generate heat. The heat exchanger is heated by this heat, and the exhaust gas in the exhaust pipe is warmed through the heat exchanger. Further, when the temperature of the exhaust gas discharged from the internal combustion engine becomes higher than a predetermined temperature, the reaction material in the reactor is heated by the heat of the exhaust gas through the heat exchanger, and NH ₃ is desorbed from the reaction material in the reactor. To do. Then, the desorbed NH ₃ is collected in the reservoir through the supply pipe.

JP 2014-85093 A

  In the above prior art, the reservoir and the supply pipe are connected by welding, but the reaction medium may leak from the welded connection due to, for example, the vibration of the vehicle or the vehicle coming into contact with an obstacle. There is. Moreover, there is a possibility that the reaction medium leaks from the reservoir due to a hole in the reservoir itself. If the reaction medium leaks from the reservoir, the amount of the reaction medium for chemically reacting with the reaction material in the reactor to generate heat decreases, so that the exhaust gas in the exhaust pipe cannot be sufficiently warmed, and the catalyst warms up. There is a risk that the machine performance will deteriorate. For this reason, it is necessary to detect leakage of the reaction medium from the reservoir. However, since the outside of the reservoir is an open system, it is difficult to detect the reaction medium itself leaking outside the reservoir.

  An object of this invention is to provide the chemical heat storage apparatus which can detect reliably the leak of the reaction medium from a storage device.

  A chemical heat storage device according to the present invention includes a reactor having a reaction material that generates heat by a chemical reaction with a reaction medium and desorbs the reaction medium by heat storage, a reservoir that stores the reaction medium, and a reactor and a reservoir. A supply pipe connected to the supply pipe, a valve disposed in the supply pipe for opening and closing a flow path of the reaction medium, and when the valve is closed after the reaction medium is recovered from the reactor into the storage tank, A first storage amount calculation unit for calculating a storage amount of the reaction medium present, a second storage amount calculation unit for calculating a storage amount of the reaction medium present in the reservoir after a predetermined time has elapsed since the valve was closed, A leakage determination unit for determining whether or not the reaction medium is leaking from the reservoir based on the storage amount of the reaction medium calculated by the first storage amount calculation unit and the second storage amount calculation unit, respectively, The determination unit is calculated by the first storage amount calculation unit. The difference between the storage amount of the reaction medium and the storage amount of the reaction medium calculated by the second storage amount calculation unit is calculated, and when the difference value becomes larger than a predetermined value, the reaction medium leaks from the reservoir. It is determined that

  In the chemical heat storage device according to the present invention, the storage amount of the reaction medium calculated when the valve is closed after the reaction medium is recovered from the reactor through the supply pipe and into the reservoir is a predetermined time after the valve is closed. When the storage amount of the reaction medium calculated after elapses is less than a predetermined value, it is determined that the reaction medium is leaking from the reservoir. As described above, by using the index of the difference in the storage amount of the reaction medium existing in the reservoir, it is possible to reliably detect the leakage of the reaction medium from the reservoir.

  A temperature sensor that detects a temperature in the reservoir, and a pressure sensor that detects a pressure in the reservoir, wherein the first storage amount calculator and the second storage amount calculator are detected by the temperature sensor. The storage amount of the reaction medium may be calculated based on the internal temperature and the pressure in the reservoir detected by the pressure sensor. In this case, since the storage amount of the reaction medium is calculated in consideration of both the temperature and pressure fluctuations in the reservoir, the storage amount of the reaction medium can be accurately calculated. As a result, leakage of the reaction medium from the reservoir can be detected more reliably.

  The first storage amount calculation unit and the second storage amount calculation unit calculate the saturated vapor pressure of the reaction medium based on the temperature in the reservoir detected by the temperature sensor, and the reservoir detected by the saturated vapor pressure and the pressure sensor. The storage amount of the reaction medium may be calculated based on the relative pressure to the internal pressure. By comprising in this way, the storage amount of the reaction medium can be easily calculated based on the temperature and pressure in the reservoir.

  ADVANTAGE OF THE INVENTION According to this invention, the chemical heat storage apparatus which can detect reliably the leak of the reaction medium from a storage device is provided.

It is a schematic block diagram which shows the exhaust gas purification system provided with the chemical heat storage apparatus which concerns on one Embodiment of this invention. Is a flow diagram illustrating the processing procedure of the control unit for detecting the leakage of NH ₃ from the adsorber. It is a conceptual diagram illustrating the operation of detecting the leakage of NH ₃ from the adsorber. It is a diagram illustrating a method of calculating the NH ₃ storage amount of the first storage amount calculating unit and the second storage amount calculation unit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  FIG. 1 is a schematic configuration diagram showing an exhaust gas purification system apparatus according to an embodiment of the present invention. In FIG. 1, an exhaust gas purification system 1 is disposed in an exhaust system of a diesel engine 2 (hereinafter simply referred to as an engine 2) that is an internal combustion engine of a vehicle, and contains harmful substances (environment) contained in exhaust gas discharged from the engine 2. Purify (pollutants).

  An exhaust gas purification system 1 includes a heat exchanger 4, an oxidation catalyst (DOC: Diesel Oxidation Catalyst) 5, which are arranged in order from an upstream side to a downstream side in an exhaust pipe 3 that is an exhaust passage connected to an engine 2. A diesel exhaust particulate filter (DPF) 6, a selective catalytic reduction (SCR) 7, and an oxidation catalyst (ASC: Ammonia Slip Catalyst) 8 are provided.

The heat exchanger 4 transfers heat between the exhaust gas from the engine 2 and a reaction material 13 described later. The heat exchanger 4 has a honeycomb structure, for example. The DOC 5 oxidizes and purifies HC and CO contained in the exhaust gas. The DPF 6 collects and removes particulate matter (PM) contained in the exhaust gas. The SCR 7 reduces and purifies NOx contained in the exhaust gas with urea or ammonia (NH ₃ ). The ASC 8 oxidizes and purifies NH ₃ that has passed through the SCR 7 and has flowed downstream of the SCR 7.

  An exhaust gas temperature sensor 18 is disposed on the upstream side and the downstream side of the heat exchanger 4 in the exhaust pipe 3. The exhaust gas temperature sensor 18 detects the temperature of exhaust gas from the engine 2 flowing in the exhaust pipe 3. The temperature information of the exhaust gas detected by the exhaust gas temperature sensor 18 is output to the control unit 20 described later. The upstream side and the downstream side in the present embodiment are the upstream side and the downstream side in the direction in which the exhaust gas flows through the exhaust pipe 3.

Further, the exhaust gas purification system 1 includes a chemical heat storage device 10 that heats (warms up) the heat exchanger 4 that is a heating target without using external energy by utilizing a reversible chemical reaction. Specifically, the chemical heat storage device 10 stores heat (exhaust heat) of the exhaust gas inside by separating a reaction material 13 and a reaction medium described later from each other. The chemical heat storage device 10 supplies the reaction medium to the reaction material 13 when necessary, causes the reaction medium and the reaction material 13 to chemically react (chemical adsorption), and uses the reaction heat at the time of the chemical reaction to generate heat. The exchanger 4 is heated. In this embodiment, ammonia (NH ₃ ) is used as a reaction medium.

  The chemical heat storage device 10 includes a reactor 11, an adsorber (storage device) 12, a supply pipe 15 that connects the reactor 11 and the adsorber 12, and an electromagnetic valve (valve) 16 disposed in the supply pipe 15. And a control unit 20, a temperature sensor 41, and a pressure sensor 43.

The reactor 11 is disposed around the exhaust pipe 3 so as to correspond to the portion of the exhaust pipe 3 where the heat exchanger 4 is provided. The reactor 11 includes a reaction material 13 that generates heat by chemically reacting with NH ₃ that is a gaseous reaction medium, and desorbs NH ₃ by receiving exhaust heat. The reaction material 13 disposed inside the reactor 11 has a heat conductivity higher than that of the reaction material 13, and is a heat conduction material that serves as a heat conduction path for transferring heat generated in the reaction material 13 to the heat exchanger 4. (Not shown) may be mixed to form a molded pellet.

  As the reaction material 13, a halide represented by the composition formula MXa is used. Here, M is an alkaline earth metal such as Mg, Ca, or Sr, or a transition metal such as Cr, Mn, Fe, Co, Ni, Cu, or Zn. X is Cl, Br, I or the like. a is a number specified by the valence of M, and is 2-3. In addition, as the heat conducting material, a material such as carbon fiber, carbon black, or graphite sheet is used. The molded pellets are produced by simultaneously pressing and solidifying the reaction material 13 and the heat conductive material in a mold and mixing them. Note that the molded pellets may be press-molded in a state where a plurality of types of heat conductive materials are mixed in the reaction material 13.

Adsorber 12, elimination of the holding and NH ₃ by physical adsorption of NH ₃ contains an adsorbent 14 capable. As the adsorbent 14, activated carbon, carbon black, mesoporous carbon, nanocarbon, zeolite, or the like is used. Adsorber 12, by physically adsorbed NH ₃ to the adsorbent 14, storing NH _3.

The supply pipe 15 constitutes a supply flow path in which NH ₃ can flow between the reactor 11 and the adsorber 12. The electromagnetic valve 16 is an open / close valve that opens and closes the NH ₃ flow path between the reactor 11 and the adsorber 12. The electromagnetic valve 16 is controlled by the control unit 20.

  The temperature sensor 41 and the pressure sensor 43 are disposed in the adsorber 12, for example. The temperature sensor 41 detects the temperature in the adsorber 12. The pressure sensor 43 detects the pressure in the adsorber 12. The temperature information in the adsorber 12 detected by the temperature sensor 41 and the pressure information in the adsorber 12 detected by the pressure sensor 43 are output to the control unit 20.

  The control unit 20 includes a valve opening / closing unit 21, a first storage amount calculation unit 22, a second storage amount calculation unit 23, a leak determination unit 24, and a display output unit 25. The valve opening / closing unit 21 controls the open / close state of the electromagnetic valve 16 based on the temperature of the exhaust gas indicated by the temperature information output from the exhaust gas temperature sensor 18 described above.

The first storage amount calculation unit 22 and the second storage amount calculation unit 23 are the adsorber 12 indicated by the temperature in the adsorber 12 indicated by the temperature information output from the temperature sensor 41 and the pressure information output from the pressure sensor 43. The amount of NH ₃ adsorbed on the adsorbent 14 in the adsorber 12 (NH ₃ storage amount) is calculated based on the internal pressure. The first storage amount calculation unit 22 calculates the NH ₃ storage amount in the adsorber 12 when the solenoid valve 16 is closed after NH ₃ is recovered from the reactor 11 into the adsorber 12. The second storage amount calculation unit 23 calculates the NH ₃ storage amount in the adsorber 12 after a predetermined time has elapsed since the electromagnetic valve 16 was closed.

The leakage determination unit 24 determines whether NH ₃ is leaking from the adsorber 12 based on the NH ₃ storage amount calculated by the first storage amount calculation unit 22 and the second storage amount calculation unit 23, respectively. Thereby, the leakage of NH ₃ from the adsorber 12 is detected. When the leakage determination unit 24 determines that NH ₃ is leaking from the adsorber 12, the display output unit 25 outputs the determination result to, for example, the display unit 30 mounted on the vehicle. By displaying information indicating the determination result output from the display output unit 25 on the display unit 30, the driver of the vehicle can recognize that NH ₃ is leaking from the adsorber 12. The details of the operation of the control unit 20 for detecting the leakage of NH ₃ from the adsorber 12 will be described later.

In such a chemical heat storage device 10, when the temperature of the exhaust gas from the engine 2 is lower than a predetermined temperature, NH ₃ is supplied from the adsorber 12 to the reactor 11 through the supply pipe 15, and the reactant 13 ( For example, MgCl ₂ ) and NH ₃ chemically react and chemisorb (coordinate bond), and heat is generated from the reaction material 13. That is, a reaction from the left side to the right side (exothermic reaction) in the following reaction formula (A) occurs. The heat exchanger 4 is heated by the heat generated in the reactor 11, and the exhaust gas is warmed through the heat exchanger 4. Then, the DOC 5 is heated by the warmed exhaust gas.
MgCl ₂ + xNH ₃ ＭｇMg (NH ₃ ) xCl ₂ + heat (A)

On the other hand, when the temperature of the exhaust gas from the engine 2 becomes higher than a predetermined temperature, the exhaust heat is given to the reaction material 13 in the reactor 11 through the heat exchanger 4 so that NH ₃ is desorbed from the reaction material 13. . That is, a reaction (regeneration reaction) from the right side to the left side in the above reaction formula (A) occurs. Then, NH ₃ desorbed from the reaction material 13 returns from the reactor 11 to the adsorber 12 through the supply pipe 15 and is physically adsorbed (recovered) by the adsorbent 14 of the adsorber 12.

Next, referring to FIG. 2 and FIG. 3, the operation of the controller 20 for detecting NH ₃ leakage from the adsorber 12 when NH ₃ is recovered from the reactor 11 to the adsorber 12. This will be described in detail. FIG. 2 is a flowchart showing a processing procedure of the control unit 20 for detecting leakage of NH ₃ from the adsorber 12. FIG. 3 is a conceptual diagram showing an operation for detecting leakage of NH ₃ from the adsorber 12.

As shown in FIG. 2, the valve opening / closing unit 21 first determines whether or not the temperature of the exhaust gas indicated by the temperature information output from the exhaust gas temperature sensor 18 is equal to or higher than a predetermined temperature (for example, 260 ° C. to 300 ° C.). (S1). When the temperature of the exhaust gas is equal to or higher than a predetermined temperature (S1; YES), the valve opening / closing unit 21 transmits a signal for opening the electromagnetic valve 16 to the electromagnetic valve 16 to open the electromagnetic valve 16 (S2, FIG. 3). (See (a)). Thereby, NH ₃ moves from the reactor 11 to the adsorber 12 through the supply pipe 15, and the pressure in the adsorber 12 increases. On the other hand, when the temperature of the exhaust gas is lower than the predetermined temperature (S1; NO), the valve opening / closing unit 21 returns to the processing of S1, and repeats the determination of S1 until the temperature of the exhaust gas becomes equal to or higher than the predetermined temperature.

Subsequent to the process of S2, the first storage amount calculation unit 22 calculates the NH ₃ storage amount A in the adsorber 12 by recovering NH ₃ from the reactor 11 through the supply pipe 15 into the adsorber 12. (S3). The NH ₃ storage amount A is calculated based on the temperature and pressure in the adsorber 12 and the adsorption characteristics of the adsorbent 14. Details of the calculation method of the NH ₃ storage amount A will be described later with reference to FIG.

Following the process of S3, the valve opening / closing unit 21 determines whether the NH ₃ storage amount A is equal to or greater than a predetermined amount (S4). Here, the predetermined amount is, for example, a value that is about 10% to 20% lower than the ideal value set in advance as the amount of NH ₃ required for 100% reaction with the reactant 13 in the reactor 11.

When the NH ₃ storage amount A is equal to or larger than the predetermined amount (S4; YES), the valve opening / closing unit 21 transmits a signal for closing the electromagnetic valve 16 to the electromagnetic valve 16 to close the electromagnetic valve 16 (S5, (See (b) of FIG. 3). The NH ₃ storage amount A at this time is equal to the predetermined amount. The NH ₃ storage amount A at this time is a reference for determining by the leakage determination unit 24 whether or not NH ₃ is leaking from the adsorber 12 described below. On the other hand, when the NH ₃ storage amount A is less than the predetermined amount (S4; NO), the valve opening / closing unit 21 returns to the processing of S3, and repeats the processing of S3 to S4 until the NH ₃ storage amount becomes equal to or larger than the predetermined amount. .

Subsequent to the processing of S5, the second storage amount calculation unit 23 determines whether or not a predetermined time (for example, about 60 seconds) has elapsed since the solenoid valve 16 was closed after NH ₃ was collected (S6). . When a predetermined time has elapsed after the solenoid valve 16 is closed (S6; YES), the second storage amount calculation unit 23 calculates the NH ₃ storage amount B present in the adsorber 12 (S7). Similarly to the NH ₃ storage amount A, the NH ₃ storage amount B is calculated based on the temperature and pressure in the adsorber 12 and the adsorption characteristics of the adsorbent 14. On the other hand, when the predetermined time has not elapsed since the solenoid valve 16 was closed (S6; NO), the second storage amount calculation unit 23 returns to the process of S6 and repeats the determination of S6 until the predetermined time elapses.

Following the processing of S7, the leakage determination unit 24 calculates the NH ₃ calculated by the first storage amount calculation unit 22 when the solenoid valve 16 is closed after NH ₃ is recovered from the reactor 11 into the adsorber 12. The difference between the storage amount A and the NH ₃ storage amount B calculated by the second storage amount calculation unit 23 after a lapse of a predetermined time after the electromagnetic valve 16 is closed is calculated, and whether or not the difference is larger than a predetermined value. Is determined (S8). The predetermined value here is, for example, a value of 10% of the NH ₃ storage amount A. For example, when the NH ₃ storage amount A is 100 g, 10 g which is a value of 10% of the NH ₃ storage amount A is set as the predetermined value. In this case, when the NH ₃ storage amount B is less than 90% of the NH ₃ storage amount A, that is, less than 90 g, it is determined that the difference between the NH ₃ storage amount A and the NH ₃ storage amount B is greater than the predetermined value. The

When the difference between the NH ₃ storage amount A and the NH ₃ storage amount B is larger than the predetermined value (S8; YES), the leakage determination unit 24 determines that NH ₃ is leaking from the adsorber 12 (S9, FIG. 3). (See (c)). Subsequently, the display output unit 25 outputs the determination result to the display unit 30 (S10), and ends the process. On the other hand, when the difference between the NH ₃ storage amount A and the NH ₃ storage amount B is equal to or smaller than a predetermined value (S8; NO), the leakage determination unit 24 determines that NH ₃ is not leaking from the adsorber 12 (S11). , (D) of FIG. 3), the process is terminated. Through the operation of the control unit 20 described above, leakage of NH ₃ from the adsorber 12 is detected.

Next, a method for calculating the NH ₃ storage amounts A and B by the first storage amount calculation unit 22 and the second storage amount calculation unit 23 will be described with reference to FIG. FIG. 4 is a diagram illustrating a method of calculating the NH ₃ storage amount by the first storage amount calculation unit 22 and the second storage amount calculation unit 23. FIG. 4A is a graph showing the relationship between the temperature in the adsorber 12 and the saturated vapor pressure of NH ₃ , the horizontal axis shows the temperature [° C.] in the adsorber 12, and the vertical axis shows NH _3. The saturated vapor pressure [kPa] is shown. FIG. 4B is a graph showing the relationship between the relative pressure of the adsorbent 14 arranged in the adsorber 12 and the amount of NH ₃ stored, the horizontal axis indicates the relative pressure, and the vertical axis indicates the NH ₃ storage. The amount [g] is indicated. Here, the relative pressure is the pressure in the adsorber 12 with respect to the saturated vapor pressure of NH ₃ . Note that the NH ₃ storage amount relative to the relative pressure of the adsorbent 14 is obtained in advance by experiments.

In the control unit 20, the relationships shown in the graphs of FIGS. 4A and 4B are set in advance. The first storage amount calculator 22 and the second storage amount calculator 23 calculate the NH ₃ storage amount using the relationship. Specifically, first, the first storage amount calculation unit 22 and the second storage amount calculation unit 23 are based on the temperature T in the adsorber 12 indicated by the temperature information output from the temperature sensor 41, as shown in FIG. The saturated vapor pressure Psat of NH ₃ is calculated using the relationship shown in the graph. Subsequently, the first storage amount calculation unit 22 and the second storage amount calculation unit 23 calculate the saturated vapor pressure Psat of NH ₃ and the pressure P in the adsorber 12 indicated by the pressure information output from the pressure sensor 43. Based on the above, a relative pressure Prela (= P / Psat) which is a ratio of the pressure P to the saturated vapor pressure Psat is calculated. Then, the first storage amount calculation unit 22 and the second storage amount calculation unit 23 calculate the NH ₃ storage amount using the relationship shown in the graph of FIG. 4B based on the calculated relative pressure Prela. As described above, the first storage amount calculation unit 22 and the second storage amount calculation unit 23 calculate the NH ₃ storage amount.

As described above, according to the chemical heat storage device 10 according to the present embodiment, the NH ₃ storage amount calculated when the solenoid valve 16 is closed after the NH ₃ is recovered from the reactor 11 through the supply pipe 15 into the adsorber 12. In contrast, when the NH ₃ storage amount B calculated after a lapse of a predetermined time after the electromagnetic valve 16 is closed becomes smaller than a predetermined value, it is determined that NH ₃ is leaking from the adsorber 12. As described above, by using an index called the difference in the amount of NH ₃ stored in the adsorber 12, leakage of NH ₃ from the adsorber 12 can be reliably detected.

In particular, in the prior art, since the outside of the adsorber 12 is an open system, it has been difficult to detect NH ₃ itself leaking to the outside of the adsorber 12. For example, when the chemical heat storage device 10 is mounted on a vehicle, NH ₃ leaking from the adsorber 12 is diffused by an air flow generated while the vehicle is running. In this case, there is a problem that it is difficult to detect the NH ₃ itself leaking outside the adsorber 12. On the other hand, according to the present embodiment, as described above, it is possible to reliably detect the leakage of NH ₃ from the adsorber 12 without detecting the NH ₃ itself leaking to the outside.

Further, according to the present embodiment, the NH ₃ storage amount is calculated in consideration of both the temperature T and the pressure P in the adsorber 12, so that the NH ₃ storage amount can be accurately calculated. . As a result, NH ₃ leakage from the adsorber 12 can be detected more reliably.

The first storage amount calculation unit 22 and the second storage amount calculation unit 23 calculate the saturated vapor pressure Psat of NH ₃ based on the temperature T in the adsorber 12 detected by the temperature sensor 41, and the calculated saturated vapor pressure The NH ₃ storage amount is calculated based on the relative pressure Prela between Psat and the pressure P in the adsorber 12 detected by the pressure sensor 43. Therefore, the NH ₃ storage amount can be easily calculated based on the temperature T and the pressure P in the adsorber 12.

  As mentioned above, although various embodiment of this invention was described, this invention is not limited to the said embodiment, It deform | transformed in the range which does not change the summary described in each claim, or applied to others It may be a thing.

The first storage amount calculation unit 22 and the second storage amount calculation unit 23 may calculate, for example, an NH ₃ recovery rate instead of the NH ₃ storage amount, and the leak determination unit 24 calculates the calculated NH ₃ recovery rate. Whether NH ₃ is leaking from the adsorber 12 may be determined based on the above. Here, the NH ₃ recovery rate is, for example, the amount of NH ₃ required for complete reaction with the reaction material 13 in the reactor 11 as a reference value (100%) and recovered in the adsorber 12 with respect to the reference value. The ratio of the amount of NH ₃ is shown.

  The position of the exhaust gas temperature sensor 18 is not limited to the upstream side and the downstream side of the heat exchanger 4 in the exhaust pipe 3, and may be arranged at any position in the exhaust pipe 3. Further, instead of the exhaust gas temperature sensor 18 or in addition to the exhaust gas temperature sensor 18, a heater temperature sensor is provided in the reactor 11, and the valve opening / closing part 21 is provided based on the temperature of the reactor 11 detected by the heater temperature sensor. The open / close state of the electromagnetic valve 16 may be controlled.

In the above embodiment, by the information indicating the determination result output from the display output unit 25 is displayed on the display unit 30, the driver of the vehicle was able to recognize that the leak NH ₃ from adsorber 12 However, the method of notifying the driver of NH ₃ leakage from the adsorber 12 is not limited to this. For example, the driver may be notified of NH ₃ leakage from the adsorber 12 by voice or buzzer.

The reaction medium introduced into the reactor 11 is not limited to NH ₃ and may be, for example, H ₂ O, alcohol, CO ₂ or the like. Note that CaO, MnO, CuO, Al ₂ O ₃ or the like is used as a reaction material that is chemically reacted with H ₂ O.

  In the above embodiment, the exhaust gas is heated via the heat exchanger 4 provided in the exhaust system of the diesel engine 2, but the present invention is not particularly limited thereto, and is provided in the exhaust system of the gasoline engine. A device that heats exhaust gas via a heat exchanger, or a device that heats a heat medium via a heat exchanger other than the exhaust system of the engine may be used. Further, a catalyst coat layer may be formed on a part or all of the surface of the heat exchanger provided in the exhaust system of the engine. That is, the catalyst may be directly warmed up by a chemical heat storage device instead of warming up the catalyst via a heat exchanger.

  DESCRIPTION OF SYMBOLS 10 ... Chemical heat storage apparatus, 11 ... Reactor, 12 ... Adsorber (reservoir), 13 ... Reactant, 15 ... Supply pipe, 16 ... Solenoid valve (valve), 22 ... 1st storage amount calculation part, 23 ... 1st 2 storage amount calculation part, 24 ... leak determination part, 41 ... temperature sensor, 43 ... pressure sensor.

Claims (3)

A reactor having a reaction material which generates heat by chemical reaction with the reaction medium and desorbs the reaction medium by storing heat;
A reservoir for storing the reaction medium;
A supply pipe connecting the reactor and the reservoir;
A valve disposed in the supply pipe to open and close the flow path of the reaction medium;
A first storage amount calculator that calculates a storage amount of the reaction medium present in the reservoir when the valve is closed after the reaction medium is recovered from the reactor into the reservoir;
A second storage amount calculation unit for calculating a storage amount of the reaction medium present in the reservoir after a predetermined time has elapsed since the valve was closed;
A leakage determination unit that determines whether or not the reaction medium is leaking from the reservoir based on the storage amount of the reaction medium calculated by the first storage amount calculation unit and the second storage amount calculation unit, respectively; ,
With
The leakage determination unit calculates a difference between the storage amount of the reaction medium calculated by the first storage amount calculation unit and the storage amount of the reaction medium calculated by the second storage amount calculation unit, A chemical heat storage device that determines that the reaction medium is leaking from the reservoir when the difference value is greater than a predetermined value. A temperature sensor for detecting the temperature in the reservoir;
A pressure sensor for detecting the pressure in the reservoir,
The first storage amount calculation unit and the second storage amount calculation unit are based on the temperature in the reservoir detected by the temperature sensor and the pressure in the reservoir detected by the pressure sensor. Calculate the storage amount of the reaction medium,
The chemical heat storage device according to claim 1. The first storage amount calculation unit and the second storage amount calculation unit calculate a saturated vapor pressure of the reaction medium based on the temperature in the reservoir detected by the temperature sensor, and the saturated vapor pressure and the pressure Calculating a storage amount of the reaction medium based on a relative pressure detected by a sensor and a pressure in the reservoir;
The chemical heat storage device according to claim 2.

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