JP2644113B2 - Operation method of heat storage system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a heat storage system in which a heat medium is circulated between a heat source device and a heat storage tank to store the generated heat or cold heat of the heat source device in the heat storage tank.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned heat storage system,
As an output of the heat source device, an output capable of storing a predetermined amount of heat in the heat storage tank by circulating the heat medium for a predetermined time is set as the output of the heat source device, and the heat source device is continuously operated at the set output during the heat storage operation period over the predetermined time. Thus, a predetermined amount of heat is stored in the heat storage tank.

[0003]

However, the heat storage capacity qs per unit time in the heat storage tank gradually decreases as the heat storage progresses and the heat storage state of the heat storage tank approaches a saturated state, as shown in FIG. Therefore, in the conventional operating method of operating the heat source device at a constant output, for example, in calculation, the output of the heat source device capable of storing a predetermined amount of heat in the heat storage tank by the circulation of the heat medium for a predetermined time T (in other words, the output of the heat source device) As the generated heat amount per unit time qh), the integrated value of the heat source device generated heat amount qh over the predetermined time T (corresponding to the area abcd in FIG. 4) and the target heat storage amount Qs as the integrated value of the heat storage capacity qs over the predetermined time T (Equivalent to the area aed in FIG. 4), the output qh1 is set to be exactly equal to the heat quantity qh generated by the heat source device in the first half of the heat storage operation.
1 is smaller than the heat storage capacity qs, the area b
The heat storage operation proceeds while the heat storage of the heat amount corresponding to ef is not completed. On the other hand, in the latter half of the heat storage operation, the heat storage amount qs is actually reduced, and the generated heat amount qh1 of the heat source device becomes the heat storage amount q
s, the temperature of the circulating heat medium becomes abnormally high in the case of heat storage, and the temperature of the circulating heat medium becomes abnormally low in the case of cold heat storage. You need to stop driving, and as a result,
The heat storage of the target heat storage amount Qs corresponding to the area aed cannot be actually completed after the elapse of the predetermined time T, and thus the heat storage heat consumption operation after the heat storage operation (for example, the heating operation using the storage heat and the cooling operation using the storage cold) There was a problem that hindered the implementation of the operation plan as a whole, including

[0004] Even if the output qh of the heat source device is set to a value larger than qh1 (for example, qh2), the frequency of interrupting the operation of the heat source device increases only, and the above problem still remains. If the output qh of the heat source device is set to a value smaller than the above qh1 (for example, qh3), the integrated value of the heat source device generated heat amount qh3 over the predetermined time T becomes the target as the integrated value of the heat storage capacity qs over the predetermined time T. Since the heat storage amount is lower than the heat storage amount Qs, it is impossible to complete the heat storage of the target heat storage amount Qs in the predetermined time T from the viewpoint of calculation.

An object of the present invention is to solve the above problem by employing a rational operation mode.

[0006]

A feature of the method of operating a heat storage system according to the present invention is that a heat medium is circulated between a heat source device and a heat storage tank so that generated heat or cold generated by the heat source device is transferred to the heat storage tank. When storing heat, the target heat supply medium is supplied to the heat storage tank as the target temperature while operating the heat source device.
A predetermined heat medium circulating between the heat source device and the heat storage tank;
By the heat storage operation for a time, a temperature at which a predetermined amount of heat can be stored in the heat storage tank is set, and in the operation process of the heat storage operation , the heat storage capacity per unit time in the heat storage tank changes. In order to maintain the heating medium delivery temperature at the target supply temperature, the detected temperature of the circulating heating medium is
Adjusting the output of the heat source device on the basis of the heat storage tank so that the heat storage capacity per unit time in the heat storage tank and the amount of heat generated per unit time of the heat source device are kept in an equilibrium state. It is as follows.

[0007]

[Function] In other words, when the heat source device is operated at a certain output, the heat storage capacity of the heat source device is equal to the heat storage capacity per unit time in the heat storage tank. When the amount changes, the amount of heat generated per unit time of the heat source device becomes more or less than the heat storage capacity per unit time in the heat storage tank, so that the temperature of the heat medium returning from the heat storage tank to the heat source device changes, Along with this, the temperature of the heat medium delivered from the heat source device operating at a constant output changes.

Therefore, in the operation process of the heat storage operation,
Therefore, if the heat storage capacity per unit time in the heat storage tank changes, by adjusting the output of the heat source device so that the heat medium delivery temperature from the heat source device is maintained at a constant temperature, heat storage per unit time can be achieved. the amount regardless to changes sequentially through its thermal storage operation period, it is possible to maintain a state in which the heat generation amount per unit time of the heat source unit and the heat storage can amount per unit time in the heat storage tank is balanced, also, the circulation It is also possible to avoid abnormally high and abnormally low temperatures of the heat medium, and also to avoid interrupting the operation of the heat source device due to abnormally high and abnormally low temperatures of the circulating heat medium.

[0009] Therefore, as the target supply temperature of the heat medium for the heat storage tank, the temperature was set to be heat accumulating a predetermined amount of heat to the heat storage tank by thermal storage operation for a predetermined time, and, the thermal storage operation
During the operation process, the detected temperature of the circulating heat medium is adjusted so that the temperature of the heat medium delivered from the heat source device is maintained at its target supply temperature.
Based by adjusting the output of the heat source device, the thermal storage operation process
In which the amount of heat generated per unit time of the heat source device follows the change in the amount of heat that can be stored per unit time
In this state, the heat storage is advanced while balancing the amount of heat generated per unit time of the heat source device with the heat storage capacity per unit time in the heat storage tank. That is, in the example of FIG. While the heat storage capacity per unit qs changes with time along the ed line, the heat storage unit also advances the heat storage while changing the generated heat amount per unit time qh similarly along the ed line, and the predetermined time T elapses. At this point, the heat storage of the target predetermined amount of heat Qs can be accurately completed.

[0010]

According to the present invention, with the above-described actions,
By Ru accurately can heat accumulation predetermined heat target <br/> in thermal storage operation for a predetermined time, the heat storage operation and the operation plan of the entire system, including the subsequent thermal storage heat consumption operation more accurate than previously, and smoothly Will be able to accomplish it. By the way,
Regarding the output adjustment of the heat source device in this type of heat storage system
As another method, Japanese Patent Application Laid-Open No. 2-64334 discloses
As can be seen, the output of the heat pump as a heat source device
There is a method of adjusting (capacity) according to the outside air temperature. Toes
This alternative method uses a heat pump to store heat.
As a characteristic, the higher the outside air temperature, the heavier the heat source device.
Increase in the real output (real capacity) of the pump
As a result, the actual output of the heat pump
As a result, it becomes too large,
In the heat storage tank against the temperature rise per unit time of the ring heat medium
Temperature rise of heat storage material per unit time cannot follow
In the state, the temperature of the circulating heat medium can be operated by the heat pump.
The upper temperature limit (ie, the operation of the heat pump in terms of equipment protection)
(The temperature at which the rotation stops automatically), and the heat storage is still insufficient.
Heat pump shuts down in spite of minutes
Heat depending on the outside air temperature
Adjust the pump output (i.e., the higher the outside air temperature,
The heat pump output to the lower side)
Heat pump operation by circulating heat transfer medium temperature
Delay reaching the maximum possible temperature, which
They try to deter inconvenience. But this another
In the method, the actual output of the heat pump changes according to the outside air temperature.
Between heat pump output and heat storage capacity due to
Deformation can be suppressed, but heat source equipment according to the outside air temperature
Because the output of the storage is adjusted, the heat storage progresses and the heat storage in the heat storage tank
Unit time in the heat storage tank as the state approaches saturation
Heat storage tanks, such that the heat storage capacity per unit gradually decreases
Due to the heat storage characteristics of
Heat generation and heat storage per unit time in the heat storage tank
It is not possible to cope with the imbalance between the quantity and
For example, in the storage of warm heat, the heat storage
Even if the heat storage capacity per unit time in the tank is large
Nevertheless, because the outside air temperature at that time was high,
By adjusting the output to the lower side, the heat source device
Heat generated per unit time per unit time
An unbalanced condition such as smaller than the heat storage capacity is caused.
Or conversely, the unit in the heat storage tank at the end of the heat storage operation
Despite the small amount of heat storage per hour,
The output of the heat source device increases due to the low outside air temperature
By adjusting the return, the unit time of the heat source device
The amount of heat generated per unit is the amount of heat that can be stored in the heat storage tank per unit time.
May cause an unbalanced condition such as larger than
There is. In this regard, according to the present invention, as described above, the heat source device
Maintain the heating medium delivery temperature from the unit at the target supply temperature described above.
In this way, the output of the heat source device is
By adjusting, heat storage per unit time in the heat storage tank
Equilibrium between possible amount and heat generated per unit time of heat source device
Therefore, the heat storage characteristics of the heat storage tank
Changes in the amount of heat that can be stored per unit time
If a heat pump is used as the heat source device,
It is also possible to match changes in the actual heat pump output due to air temperature.
In the heat storage operation process, the unit of the heat source device
Heat generation per hour and heat storage per unit time of heat storage tank
It is possible to reliably maintain the state of equilibrium with the possible amount,
This makes it possible to achieve more accurate
To complete the storage of the specified amount of heat at the point in time
Can be.

[0011]

Next, an embodiment will be described. FIG. 1 shows a system configuration of a heat storage system, in which a latent heat storage type heat storage tank 3 and an air-cooled heat pump 4 are interposed in series in a main refrigerant path 2 in which a refrigerant pump 1 is interposed. The load-side refrigerant path 6 with the exchanger 5 interposed is connected to the main refrigerant path 2 so as to form a refrigerant circulation path that goes around the heat pump 4, the load-side heat exchanger 5, and the heat storage tank 3 in this order. .

A bypass refrigerant path 7 for the load-side refrigerant path 6, that is, a refrigerant path connected in parallel with the load-side refrigerant path 6 to the main refrigerant path 2 is provided. A bypass 8 is provided.

The load-side refrigerant path 6 and the bypass refrigerant path 7 include:
A refrigerant circulation path in a heat storage operation in which the cold heat generated by the heat pump 4 is stored in the heat storage tank 3 and a cold heat consumption operation in which the heat storage cold heat is taken out of the heat storage tank 3 and applied to the cold heat consuming device via the load side heat exchanger 5. As a means for switching, a load-side solenoid valve 9 for opening and closing the load-side refrigerant passage 6 and a bypass solenoid valve 10 for opening and closing the bypass refrigerant passage 7 are provided.
Also, at the junction of the bypass passage 8 with the main refrigerant passage 2,
A merging three-way valve 11 is provided for adjusting the ratio of the amount of refrigerant passing through the heat storage tank 3 to the amount of refrigerant passing through the bypass passage 8 to adjust the amount of cold heat taken out of the heat storage tank 3.

Reference numeral 12 denotes a controller for controlling the operation, and 13
Are check valves, respectively.

The configuration of the cooling and heat consuming device includes an air conditioner 1
A cold water circulation path 15 is provided between the load side heat exchanger 5 and the load side heat exchanger 5. The cold water circulation is performed by the cold water pump 16 in the cold water circulation path 15 during the cold heat consumption operation. The refrigeration provided to the circulating chilled water from the circulating refrigerant of No. 6 is converted into an air conditioner
To be transported and supplied.

The heat storage operation is performed by a timer control in a predetermined time zone T of the day (for example, the cold heat operation is performed from 8:00 am to 6:00 pm, whereas the heat storage operation is performed from 10 pm to During the heat storage operation, the controller 12 closes the load-side solenoid valve 9 and opens the bypass solenoid valve 10, and passes the refrigerant through the bypass passage 8. The three-way valve 11 is adjusted so as to shut off the refrigerant.
As shown in FIG. 1, by operating the heat pump, the refrigerant is circulated through the bypass refrigerant path 7 in a state where the circulation of the refrigerant to the load side refrigerant path 6 is cut off, and in a state where the entire amount of the refrigerant passes through the heat storage tank 3. The refrigerant is circulated between the heat storage tank 4 and the heat storage tank 3.

The target supply temperature tss of the refrigerant to the heat storage tank 3 is a temperature at which the predetermined amount of cold energy Qs can be stored in the heat storage tank 3 during the above-mentioned predetermined time period T (for example, a temperature such as -4 to -5 ° C.). Is set in advance, and based on the detection information of the temperature sensor 17 that detects the refrigerant delivery temperature ts from the heat pump 4, as shown by a solid line in FIG.
The refrigerant delivery temperature ts from the heat pump 4 is maintained at the set target supply temperature tss, specifically, within a set allowable fluctuation range around the set target supply temperature tss (tss-Δt <ts <tss + Δt). , For example, Δt =
The output of the heat pump 4 is adjusted and controlled so as to be 0.3 ° C.).

That is, as a general characteristic of the heat storage tank 3, the heat storage capacity qs per unit time in the heat storage tank 3 is shown in FIG.
As shown in FIG. 4, the heat storage progresses and decreases as the heat storage state approaches the saturated state. On the other hand, the amount of generated cold heat qh per unit time of the heat pump 4 is qh1 as shown by the broken line in FIG. When the heat pump 4 is operated at a constant output to perform the heat storage operation, the amount of generated cold heat per unit time qh
3 is smaller than the heat storage capacity qs per unit time, and the refrigerant temperature tr returned to the heat pump 4 becomes high as shown by a broken line A in FIG. The temperature ts also becomes high and the cold heat storage efficiency decreases, and conversely, a state occurs in which the amount of generated cold heat qh1 per unit time is larger than the storable amount qs per unit time, and FIG. As shown by the symbol, the refrigerant temperature tr returning to the heat pump 4 gradually decreases, and accordingly, the refrigerant delivery temperature t from the heat pump 4
s has dropped to the device lower limit temperature td at which the automatic operation stop function on the heat pump protection is activated, and the heat pump 4
4 is interrupted, and for these reasons, a situation occurs in which the storage of the target predetermined amount of cold energy Qs corresponding to the area aed in FIG. 4 cannot be completed during the predetermined time period T.

Therefore, as described above, the temperature at which the predetermined amount of cold heat Qs can be stored in the heat storage tank 3 during the predetermined time period T is set in advance as the target supply temperature tss of the refrigerant to the heat storage tank 3, By adopting a mode in which the output of the heat pump 4 is adjusted and controlled so as to maintain the delivery temperature ts at the set target supply temperature tss, regardless of a change in the heat storage capacity qs per unit time in the heat storage tank 3, The heat storage is advanced while balancing the generated amount of cold heat qh per unit time of the heat pump 4 and the heat storage capacity qs per unit time in the heat storage tank 3, that is, the heat storage capacity qs per unit time in the heat storage tank 3.
Changes over time along the ed line in FIG.
Similarly, the amount of cold heat generated per unit time of the heat pump 4 is also changed along the ed line to advance the heat storage, whereby the heat storage of the predetermined cold heat amount Qs at the end of the predetermined time zone T can be surely ended. It is.

On the other hand, in performing the cold heat consuming operation after the heat storage operation, the controller 12 opens the load side solenoid valve 9 and
By closing the bypass solenoid valve 10 and operating the refrigerant pump 1 in this state, as shown in FIG. 2, in a state in which the circulation of the refrigerant to the bypass refrigerant path 7 is cut off, the heat pump 4 and the load side heat exchanger 5 And the heat storage tank 3 to circulate the refrigerant.

The heat storage tank 3 and the heat pump 4 for reducing the remaining heat storage in accordance with a predetermined consumption plan based on the calculation of the remaining heat storage in the heat storage tank 3 and the cooling load in the load side heat exchanger 5. , And sequentially adjusts the three-way valve 11 so that each of the amount of cold heat taken out of the heat storage tank 3 and the amount of auxiliary generated cold heat of the heat pump 4 becomes an amount corresponding to the determined load share. In addition, the output of the heat pump 4 is adjusted, so that the remaining heat stored in the heat storage tank 3 is reduced to a predetermined consumption schedule by taking out cold heat from the heat storage tank 3 (that is, cooling the refrigerant by passing through the heat storage tank 3) and performing auxiliary operation of the heat pump 4. Along with the temperature tsx corresponding to the required chilled water temperature of the air conditioner 14 (for example, the required chilled water temperature of the air conditioner 14
(Temperature of about 5 ° C. as opposed to about 5 ° C.).

Incidentally, the remaining amount of heat stored in the heat storage tank 3 is obtained by integrating the heat storage amount calculated based on the difference between the inlet and outlet refrigerant temperatures of the heat storage tank 3 and the amount of refrigerant passing through the heat storage tank 3 during the heat storage operation.
In addition to calculating the total amount of cold heat storage at the time of the completion of the heat storage operation, the integrated value of the amount of cold heat taken out calculated based on the difference between the inlet and outlet refrigerant temperatures of the heat storage tank 3 and the amount of the refrigerant passing through the heat storage tank 3 during the cold heat consumption operation is also calculated. The cooling load in the load-side heat exchanger 5 is calculated by subtracting it from the total amount of cold heat storage. It is calculated based on the passing amount.

In addition, as the consumption plan of the remaining heat storage, for example, the remaining heat storage is reduced at a predetermined reduction rate in the cold heat consumption operation time zone, and the heat storage remaining amount is set to 0 at the end of the cold heat consumption operation time zone. Is set.

[Another embodiment] Next, another embodiment will be described.

In the above embodiment, an example of cold heat storage has been described, but the present invention can be applied to warm heat storage.

The target supply temperature tss of the heat medium to the heat storage tank 3, which is a temperature at which the predetermined amount of heat Qs can be stored in the heat storage tank 3 by the circulation of the heat medium for a predetermined time T, depends on the characteristics of the heat storage tank 3 and the characteristics of the heat source device 4. An appropriate value may be determined accordingly.

The purpose of consuming the cold or warm heat stored in the heat storage tank 3 is not limited to cooling or heating.

The heat source device 4 is not limited to a heat pump, and the heat storage tank 3 is not limited to a latent heat storage type.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing a refrigerant circulation mode during a heat storage operation.

FIG. 2 is a diagram showing a refrigerant circulation mode during a cold heat consuming operation;

FIG. 3 is a graph showing a mode of adjusting a refrigerant delivery temperature.

FIG. 4 is a graph showing a change form of the heat storage capacity and a heat pump output adjustment form.

[Explanation of symbols]

 3 heat storage tank 4 heat source device tss target supply temperature T predetermined time qs heat storage capacity ts heat medium delivery temperature qh generated heat

Claims (1)

(57) [Claims] 1. A heat storage system for circulating a heat medium between a heat source device (4) and a heat storage tank (3) to store generated heat or cold generated by the heat source device (4) in the heat storage tank (3). An operation method, wherein a target supply temperature (ts) of the heat medium to the heat storage tank (3) is provided.
s), while operating the heat source device (4),
Heat medium is circulated between the heat source device (4) and the heat storage tank (3).
The heat storage tank (3) is operated by the heat storage operation for a predetermined time (T ).
A temperature at which a predetermined amount of heat (Qs) can be stored is set, and in the operation process of the heat storage operation , the heat storage device (4) responds to a change in the heat storage capacity (qs) per unit time in the heat storage tank (3). )) (T)
adjusting the output of the heat source device (4) based on the detected temperature of the circulating heat medium so as to maintain the target supply temperature (tss) at the target supply temperature (tss), and storing the heat per unit time in the heat storage tank (3). A method for operating a heat storage system, in which a possible amount (qs) and a generated heat amount (qh) per unit time of the heat source device (4) are kept in equilibrium .