JPH07309121A - Latent heat accumulating device - Google Patents

Abstract

PURPOSE:To provide a latent heat accumulating device capable of predicting the length of hot air or of the warming-up operation by measuring the heat accumulation of the inside with a compact and simple structure to inform users of thc heat accumulation. CONSTITUTION:An accumulator body 9a of a latent heat accumulating device mainly consists of a case 16 of heat insulating structure, a plurality of heat accumulating part 17, and a capacitor 18 for measuring the heat accumulation, and the heat accumulating part 17 is formed of highly heat-conductive shield fins made of copper plates, and the hydrate of barium hydrate 8 whose melting point is about 78 deg.C is filled inside as the heat accumulating medium. The capacitor 18 for measuring the heat accumulation is a capacitor where the outer shell part of the copper plate and the copper rod which is located approximately at the center are the respective electrodes, and the hydrate of barium hydrate 8 is filled as the dielectric substance, and thc respective electrodes are connected to a heat accumulation monitoring part outside the accumulator body 9a. The heat accumulation monitoring part consists of a heat accumulation calculation control part consisting of a heat accumulation monitoring control circuit, a capacitance measuring circuit and a capacitance-heat accumulation conversion memory, and a heat accumulation display part to make the LED display of the heat accumulation based on the signal of the heat accumulation calculation control cart.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a latent heat storage device arranged in a cooling water circuit of an engine.

[0002]

2. Description of the Related Art Generally, at the time of cold start of an engine, the temperature of engine cooling water is low.
There is a problem that sufficient warm air cannot be obtained from the air conditioning heater until the cooling water temperature rises, and the exhaust gas concentration becomes high because the engine body is cold.

Therefore, in Japanese Patent Laid-Open No. 63-68418, the heat generated by the engine during steady running is stored in a latent heat storage device, and the latent heat is utilized at the time of cold start and the like. Techniques for heating the room are shown.

Further, in recent years, a latent heat storage device having a heat exchanger structure is provided in series with a cooling water circuit of an engine, and while running,
There is a technique to store heat from high-temperature cooling water and to radiate heat to low-temperature cooling water to increase the temperature of the cooling water at the time of starting, thereby improving the above-mentioned problems at the time of starting the engine. Proposed.

[0005]

By the way, in the latent heat storage device as described above, when the latent heat storage device is left in a low temperature place for a long time, the amount of stored heat in the latent heat storage device is gradually released,
The heat storage amount decreases with time.

However, since the amount of heat stored in the latent heat storage device cannot be known to the user, it is necessary to predict how much temperature rise capacity the latent heat storage device can obtain when the engine is started. I can't. Therefore, depending on the amount of heat stored in the heat storage device such as when the engine is started, a large difference occurs between the actual temperature rising capacity and the expected temperature rising capacity, and the warm-up operation time becomes longer than expected, There is a problem that users will betray their expectations, such as not getting the expected warm air.

The present invention has been made in view of the above circumstances, and measures the amount of heat stored in the latent heat storage device with a small and simple structure to inform the user of the amount of stored heat of the latent heat storage device, and obtain hot air or An object of the present invention is to provide a latent heat storage device capable of predicting the length of warm-up operation time.

[0008]

In order to achieve the above object, a latent heat storage device according to the present invention has a heat storage portion in a heat storage body, and latent heat when a medium in the heat storage portion undergoes a phase change from solid to liquid. In a latent heat storage device for storing heat, a capacitor having the medium as a dielectric is formed and disposed in the heat accumulator body, and a heat storage amount monitor unit for obtaining a heat storage amount from a change in capacitance of the capacitor is provided. It is a thing.

[0009]

In the above structure, first, when heat is stored in the heat accumulator body, the heat accumulating portion in the heat accumulator body is warmed and the heat inside the heat accumulating portion undergoes latent heat when the medium undergoes a phase change from solid to liquid. It absorbs and stores heat. Similarly, the capacitor disposed inside the heat accumulator body is also warmed and the dielectric changes its phase from solid to liquid, and the ratio of both solid and liquid phases of this dielectric changes according to latent heat. Further, when the latent heat is radiated from the inside of the heat storage body, the latent heat is radiated when the medium inside the heat storage section changes from liquid to solid. Similarly, the capacitor inside the heat accumulator body also radiates latent heat to change the phase of the dielectric from liquid to solid, and the ratio between the solid and liquid phases of the dielectric changes according to the latent heat. On the other hand, since the capacitance of the capacitor also changes in accordance with the change in the ratio of the solid and liquid phases of the dielectric, the heat storage amount monitor unit changes the ratio of the solid and liquid phases from the change in the capacitance. Is calculated and the amount of heat storage is monitored.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 show an embodiment of the present invention, FIG. 1 is a schematic explanatory view showing the internal structure of a latent heat storage device, FIG. 2 is a schematic configuration of an engine cooling water circuit and an explanatory view of operation during heat storage, FIG. 3 is an operation explanatory diagram when heating is prioritized by the latent heat storage device of the engine cooling water circuit, FIG. 4 is an operation explanatory diagram when warming up is prioritized by the latent heat storage device of the engine cooling water circuit, and FIG. 5 is a heat storage amount measurement system FIG. 6 is a cross-sectional explanatory view of the heat storage amount measuring capacitor, and FIG. 7 is a flowchart of the heat storage amount measuring procedure.

In these drawings, reference numeral 1 indicates an engine body, and a cylinder block 1a of the engine body 1
A water jacket 2 that surrounds the combustion chamber of each cylinder is formed on the cylinder head 1b.

Further, one outflow port 2a of the water jacket 2 and an inflow port 2 to the water jacket 2 are provided.
A radiator 4 is interposed in the cooling water passage 3 communicating with c.

Further, the cooling water passage 3 has an outlet side of the radiator 4 and an inlet 2c of the water jacket 2.
A first water pump 5 is provided between the radiator 4 and the suction side of the first water pump 5.
A thermostat 6 that opens in a preset temperature range (for example, opening temperature 78 ° C. and opening end temperature 91 ° C.) is interposed between the thermostat 6 and the outflow side.

The other outlet 2b of the water jacket 2 and the inlet 2c of the water jacket 2 are communicated with each other by a cooling water passage 7. The cooling water passage 7 is arranged in this order from the engine side. A second water pump 8, a latent heat storage device (indicated by H / B in the figure) 9, and a heater core 10 are provided in series, and the first water pump 5 is used.
The water circulation circuit connected to the suction side of is formed.

Furthermore, the outflow side of the heater core 10 of the cooling water passage 7 and the suction side of the second water pump 8 are connected by a bypass passage 11, and the bypass passage 11 and the second water are connected. A three-way solenoid valve 12 as a switching valve is provided at the connection portion of the pump 8 with the suction side.

Here, the three-way solenoid valve 12, as will be described later, has a cooling water circuit of the engine, which stores heat of the second water pump 8 → H / B 9 → heater core 10 → second water pump 8. The water circulation circuit shown in FIG. 3 independent of the apparatus side water circulation circuit and the engine side water circulation circuit circulating in the water jacket 2, the second water pump 8 → the H / B 9 → the heater core 10 → the first water circulation circuit Water pump 5 → Water jacket 2 →
The second water pump 8, the water jacket 2, the H / B 9, and the heater core 1 shown in FIGS.
0 and 0 are selectively controlled to either one of the water circulation circuits connected in series.

The water circulation circuit on the engine side includes the outlet 2b of the water jacket 2 and the cooling water passage 7.
The intake side of the first water pump 5 is bypassed by a cooling water passage 15 formed in a throttle body 13 and an idle speed control valve (hereinafter abbreviated as ISCV) body 14. The cooling water circulating in the cooling water passage 15 causes the throttle body 13 and the I.D. S. C. The temperature of the V body 14 is appropriate (for example, preheating at cold start)
Is configured to be kept at.

On the outlet 2b side of the water jacket 2 in the cooling water passage 15, the engine side water temperature Te is provided.
The engine side water temperature sensor 21 for detecting the temperature difference between the H / B 9 of the cooling water passage 7 and the heater core 10 is
Heat storage device side water temperature sensor 2 for detecting heat storage device side water temperature Th
Two are provided. The engine side water temperature sensor 21 and the heat storage device side water temperature sensor 22 are connected to a switching control circuit (not shown) of the three-way solenoid valve 12.

In this switching control circuit, the engine side water temperature Te and the heat storage device side water temperature Th are detected, and a value obtained by adding a predetermined temperature α (about 2 to 3 ° C.) to the engine side water temperature Te is the above value. When the temperature of the water on the heat storage device side is lower than Th, the three-way solenoid valve 12 connects the bypass passage 11 and the suction side of the second water pump 8, and the cooling water circuit of the engine is connected to the water circulation circuit on the heat storage device side and the engine. When the value obtained by adding a predetermined temperature α to the engine side water temperature Te is equal to or higher than the heat storage device side water temperature Th, the water jacket 2 is formed independently of the side water circulation circuit.
Of the engine 2 is connected to the water circulating circuit in which the water jacket 2, the H / B 9 and the heater core 10 are connected in series. It is something to switch.

Further, in the switching control circuit, an engine cooling water circuit, the water circulation circuit independent of the heat storage device side water circulation circuit and the engine side water circulation circuit, the water jacket 2 and the H / B 9 are provided. The heater core 1
A water circulation circuit changeover switch (not shown) for forcibly switching and selecting the water circulation circuit in which 0 and 0 are connected in series is connected. In the figure, reference numeral 19 is a reserve tank.

On the other hand, the H / B 9 heat accumulator body 9a is
As shown in FIG. 1, it is mainly configured by a case 16, a plurality of heat storage units 17 housed in the case 16, and a heat storage amount measuring capacitor 18 arranged substantially in the same manner as the heat storage units 17. The case 16 is the outer case 16
a and an inner case 16b, the outer case 16
between the a and the inner case 16b is a high vacuum heat insulating portion 16
It is formed in a heat insulating structure provided with c.

Each of the heat storage parts 17 is formed of, for example, a shield fin made of a copper plate having high heat conductivity, and inside the shield fin, a melting point as a heat storage medium changes from liquid to solid at 78 ° C. during, barium hydroxide octahydrate _{(Ba (OH) 2 · 8H} 2 O; latent heat of fusion 88.5Wh / kg) without the temperature change is filled. Here, barium hydroxide octahydrate was selected as the heat storage medium because there is a melting point between the water temperature during normal running and the water temperature during cold state.
This is because a large amount of heat storage can be secured.

Further, as shown in FIGS. 5 and 6, the heat storage amount measuring capacitor 18 has an outer shell portion 18a formed of a copper plate which is the same member as the shield fin of the heat storage portion 17.
And a copper rod 18b electrically insulated from the center of the outer shell portion 18a and having copper electrodes as both electrodes. The outer shell portion 18a contains the heat storage as a dielectric. It is filled with the same barium hydroxide octahydrate as the medium.
In the figure, reference numeral 18c is a dielectric portion in a liquid state, and 18d.
Indicates a solid-state dielectric portion.

Further, both electrodes of the heat storage amount measuring capacitor 18 are connected to a heat storage amount monitor section 30 provided outside the heat storage body 9a, as shown in FIG. The heat storage amount monitor unit 30 calculates the heat storage amount according to a heat storage amount measurement procedure described later and controls the external display, and stores the heat storage amount based on a signal from the heat storage amount calculation control unit 31. Heat storage amount display section 3 displayed by LED
The heat storage amount calculation control unit 31 includes a heat storage monitor control circuit 31a, an electrostatic capacitance measuring circuit 31b, and an electrostatic capacitance-heat storage amount conversion memory 31c.

The capacitance measuring circuit 31b is formed in a well-known AC bridge circuit to which both electrodes of the heat storage amount measuring capacitor 18 are connected in order to obtain the capacitance C of the heat storage amount measuring capacitor 18. ing.

The electrostatic capacity-heat storage amount conversion memory 3 is also provided.
In 1c, the correlation between the ratio of both solid and liquid phases of the heat storage amount measuring capacitor 18 and the total heat storage amount of the entire H / B 9 is obtained in advance by experiments or the like and stored.

Then, the heat storage monitor control circuit 31a calculates the ratio of both solid and liquid phases from the value of the capacitance C of the heat storage amount measuring capacitor 18 obtained by the capacitance measuring circuit 31b, The electrostatic capacity-heat storage amount conversion memory 3
It is configured to convert the heat storage amount of the entire H / B 9 from the map stored in 1c and send a signal to the heat storage amount display unit 32.

Here, as shown in FIG. 6, the radius of the copper rod 18b which is one electrode of the heat storage amount measuring capacitor 18 is α, the inner radius of the outer shell portion 18a which is the other electrode is β, and the dielectric The average radius up to the boundary between the solid and liquid phases of the body is γ,
Assuming that the length (effective length as a capacitor) is L, the dielectric constant of barium hydroxide octahydrate in the liquid state is ε1, and the dielectric constant in the solid state is ε2, the heat storage amount measuring capacitor 18 is a cylindrical capacitor. Therefore, the capacitance C is calculated by the following formula. C = 2πL {Log (β / α) / ε2 + Log (γ / β) / ε1} ^(-1) (1) The unknown value in the above formula (1) is the capacitance C and the solid / liquid state. Since the average radius γ to the boundary of both phases is obtained, the average radius γ to the boundary can be obtained by calculating the capacitance C. From this result, the ratio of both solid and liquid phases can be calculated by the following equation. Can be expressed as (Γ-α) ² / (β-α) ² (2) Next, in the flowchart of FIG. 7, the heat storage amount measurement procedure executed by the heat storage amount monitor unit 30 will be described. . The program of the heat storage amount measurement procedure is executed at the time of engine start, etc., and first, in S101, the capacitance C of the heat storage amount measurement capacitor 18 is measured from the AC bridge circuit of the capacitance measurement circuit 31b, and the process proceeds to S102. Then, the heat storage monitor control circuit 31a back-calculates the average radius γ up to the boundary between the solid and liquid phases of the dielectric based on the above equation (1).

Next, in S103, the heat storage monitor control circuit 31a calculates the ratio between the solid and liquid phases of the heat storage amount measuring capacitor 18 based on the equation (2), and S
Proceeding to 104, the total heat storage amount of the entire latent heat storage device (H / B) 9 is converted from the map stored in the capacitance-heat storage amount conversion memory 31c.

Then, proceeding to S105, the heat storage monitor control circuit 31a outputs the result obtained in S104 to the heat storage amount display section 32 to display the total heat storage amount by LED,
This heat storage amount measurement procedure is ended.

Next, the operation of the above configuration will be described separately for each operating state. First, in the case of normal driving,
As shown in FIG. 2, the cooling water flowing out from the water jacket 2 of the engine body 1 is
Flows from one of the outlets 2a to the cooling water passage 3, passes through a thermostat 6 that is cooled by a radiator 4 and is in an opened state, is sucked into a first water pump 5, and again inside the water jacket 2 Circulate while cooling the main body 1.

The cooling water flowing out from the water jacket 2 is discharged from the water jacket 2 at the outlet 2b.
From the throttle body 13 and the I.V. S. C. While maintaining the temperature of the V-body 14 at an appropriate level, the V-body 14 joins the cooling water passage 7, is sucked into the first water pump 5, and is circulated again in the water jacket 2.

Further, during normal traveling, the temperature of the cooling water circulating in the cooling water circuit of the engine is as high as about 90 ° C., and the switching control circuit (not shown) operates the three-way solenoid valve 12. The outlet 2b of the water jacket 2 and the suction side of the second water pump 8 are communicated with each other.

Therefore, the cooling water flowing out from the outlet 2b of the water jacket 2 passes through the three-way solenoid valve 12 and is sucked into the second water pump 8 to generate H
/ B9 is circulated into the heater core 10 while exchanging heat (stores heat in H / B9), and the first water pump 5
And is circulated in the water jacket 2 again. That is, the cooling water circuit of the engine is a water circulation circuit in which the water jacket 2, the H / B 9 and the heater core 10 are connected in series.

Here, as shown in FIG. 1, the above H / B9
The cooling water from the water jacket 2 that has flowed in is disposed in the same manner as the plurality of heat storage parts 17 accommodated in the case 16 of the H / B 9 heat storage device main body 9a. The heat is circulated between the heat storage amount measuring capacitors 18.

Since the temperature of the circulating cooling water is about 90 ° C., the heat storage section 17 and the heat storage amount measuring capacitor 18 also have a temperature of about 90 ° C., which serves as a heat storage medium filled inside. Barium hydroxide octahydrate is in a liquid state (has accumulated heat).

Therefore, the value of the capacitance of the heat storage amount measuring capacitor 18 obtained by the heat storage monitor control circuit 31a is obtained as the value of almost all liquid state of barium hydroxide octahydrate as a dielectric. The result is displayed on the heat storage amount display section 32, and the driver is allowed to measure the above H /
It can be confirmed that the heat storage amount of B9 is sufficient.

Next, when the running is stopped from the normal running state and the engine is stopped, the circulation of the cooling water is also stopped, and the temperature of the cooling water gradually decreases to approach the outside air temperature. However, since the H / B 9 is insulated in a high vacuum by the case 16 of the heat accumulator body 9a, this H / B 9
The amount of heat stored in the outside is radiated to the outside very little.

Then, the heat is further dissipated and the above H / B9
When the internal temperature reaches about 78 ° C, the barium hydroxide octahydrate in H / B9 becomes heat of solidification (88.5 Wh / k) as latent heat.
It changes from a liquid state to a solid state while radiating heat.
At the time of this phase change, the boundary portion between the solid and liquid phases in the heat storage amount measuring capacitor 18 gradually moves from the outside toward the center of the cylinder, but the boundary portion between the solid and liquid phases moves. Accordingly, the capacitance of the heat storage amount measuring capacitor 18 also changes. Based on this change amount, the heat storage monitor control circuit 31a
Then, the map stored in the capacitance-heat storage amount conversion memory 31c is converted into the ratio of the heat storage amount of the H / B9 as a whole,
A key switch (not shown) etc. is turned on when starting the engine.
When the heat is stored, the heat storage amount display unit 32 displays the heat storage amount. Therefore, the driver can predict the warm air obtained from the H / B 9 and the required length of the warm-up operation time when starting the engine.

Next, when the driver operates the water circulation circuit changeover switch (not shown) to select the passenger compartment heating at the time of cold start, and the heat storage amount of H / B9 is sufficient. When the value obtained by adding the predetermined temperature α to the engine side water temperature Te is less than the heat storage device side water temperature Th, the switching control circuit causes the engine cooling water circuit to move to the second water pump 8 → H / B9. → The heater core 10 → The heat storage device side water circulation circuit of the second water pump 8 and the engine side water circulation circuit circulating in the water jacket 2 form an independent water circulation circuit. Therefore, the driver can obtain comfortable warm air with the heat stored in the H / B 9. On the other hand, the circulating water in the engine side water circulation circuit gradually rises due to engine heat generation. Here, the driver can confirm from the heat storage amount display section 32 that the heat storage amount of the H / B 9 is sufficient.

When the driver operates the water circulation circuit changeover switch 26 to select the heating of the passenger compartment and the value obtained by adding a predetermined temperature α to the engine side water temperature Te is equal to or higher than the heat storage device side water temperature Th. The switching control circuit includes a second water pump 8 →
The H / B 9 → the heater core 10 → the first water pump 5 → the water jacket 2 → the second water pump 8 and the water jacket 2 and the H
/ B9 and the heater core 10 form a water circulation circuit connected in series. Therefore, the driver can obtain comfortable warm air due to the heat generated by the engine. here,
Since the driver can confirm from the heat storage amount display section 32 that the heat storage amount of the H / B 9 is insufficient, as described above, the warm air obtained from the H / B 9 and the required length of warm-up operation time are required. It is possible to predict

Further, when the driver operates the water circulation circuit changeover switch to select engine warm-up, the changeover control circuit causes the engine cooling water circuit to display the second water pump 8 → H / B9. → The above heater core 10
→ The first water pump 5 → The water jacket 2 → The second water pump 8 forms a water circulation circuit in which the water jacket 2, the H / B 9 and the heater core 10 are connected in series. Therefore, the engine body 1 is effectively warmed up by the heat stored in the H / B 9.

As described above, according to the present embodiment, the engine side water temperature Te and the heat storage device side water temperature Th are relatively compared to automatically control the switching of the engine cooling water circuit. Therefore, even if the conditions such as the outside temperature change as shown in FIG. 6, it becomes possible to select the most appropriate engine cooling water circuit under the conditions, and the heat stored in the heat storage device can be selected. The energy and the heat energy generated by the engine can be effectively utilized.

Further, if the heat storage amount display section showing the heat storage amount of the latent heat storage device is constantly displayed using a gauge or the like, the driver can know the increase or decrease of the heat storage amount in real time, and the latent heat storage device It is possible to effectively use the heat according to the amount of stored heat.

The latent heat storage device of this embodiment can be applied not only to the circulation circuit of this embodiment but also to other circulation circuits having a latent heat storage device.

[0046]

As described above, according to the present invention, the amount of heat stored in the latent heat storage device is measured with a small and simple structure to inform the user of the amount of heat stored in the latent heat storage device, and the obtained warm air or It is possible to predict the length of warm-up operation time.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an internal structure of a latent heat storage device.

FIG. 2 is an explanatory diagram of a schematic configuration of an engine cooling water circuit and an operation during heat storage.

FIG. 3 is an operation explanatory diagram in the case where heating is prioritized by the latent heat storage device of the engine cooling water circuit.

FIG. 4 is an operation explanatory diagram in the case of prioritizing warm-up operation by the latent heat storage device of the engine cooling water circuit.

FIG. 5 is a schematic explanatory diagram of a heat storage amount measurement system.

FIG. 6 is an explanatory cross-sectional view of a heat storage amount measuring capacitor.

FIG. 7: Flow chart of heat storage amount measurement procedure

[Explanation of symbols]

 9 latent heat storage device 9a heat storage device body 17 heat storage unit 18 condenser 30 heat storage amount monitor unit C capacitance

Claims (1)

[Claims] 1. A heat storage part (17) in the heat storage body (9a).
In the latent heat storage device (9) for storing latent heat when the medium in the heat storage section (17) undergoes a phase change from solid to liquid, a capacitor (18) using the medium as a dielectric is formed. It is arranged in the heat storage body (9a),
A latent heat storage device comprising a heat storage amount monitor section (30) for obtaining a heat storage amount from a change in electrostatic capacity (C) of the condenser (18).