JP2628061B2 - Method and apparatus for estimating profile of heat medium temperature distribution - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for estimating a profile of a temperature distribution of a heat medium in a heat storage tank.

[Prior Art] As shown in FIG. 3, a conventional heat storage tank first cools cold water pumped by a primary cold water pump 4 from a high-temperature side terminal tank (right side in the drawing) of a cold water tank 1 as a heat storage tank. Next chilled water flow meter 6,
The primary chilled water flow rate WR is measured and cooled by the refrigerator 2 and returned to the low-temperature terminal tank of the chilled water tank 1 (left side in the drawing). The cold water pumped up by 5 is used to measure the load flow rate WL by the secondary chilled water flow meter 7 and then absorbed by the load device 3 to return to the high temperature side terminal tank. That is, the primary chilled water flow rate WR is determined by the operation state of the refrigerator 2 and the load flow rate WL
Is determined by the operation state of the load device 3 and the load amount. Therefore, the difference between the two causes the flow rate WT in the cold water tank. Moreover, since the chilled water tank 1 is generally configured by a plurality of water tank groups partitioned by a plurality of partition walls (not shown) communicating with each other, the temperature of the chilled water changes discontinuously.

Therefore, when measuring the temperature of the cooling water in the cold water tank 1, it is not possible to accurately grasp the temperature of the heat medium simply by measuring the temperature of the cold water at one location in the tank of the cold water tank 1. Therefore, a plurality of heat medium temperature detectors were required.

[Problems to be Solved by the Invention] However, in order to accurately measure the temperature of the heat medium stored in the heat storage tank, it is preferable to measure the temperature of the heat medium over the entire tank. In reality, it is difficult to realize due to location restrictions and costs, but on the other hand, if the number of heat medium temperature detectors is reduced, it is impossible to accurately grasp the heat medium temperature. .

Moreover, in recent years, the heat source device and its load device are often operated with a time lag from each other. For example, a refrigerator that produces a heat medium such as cold water is operated at midnight, and the energy is stored in a heat storage tank. Attempts have been made to effectively use late-night electricity at low cost by absorbing heat during the daytime operation of the air conditioner and utilizing it as a heat source. Therefore, in the heat storage operation, the heat radiation operation, and the simultaneous operation of the heat storage and the heat radiation, in order to perform the optimal operation control of the heat source device, the profile of the temperature distribution of the heat medium stored in the heat storage tank must be accurately determined in advance. There is a strong demand that we have to grasp.

In view of the above drawbacks, the technical problem of the present invention is to accurately grasp the profile of the heat medium exhibiting a discontinuous distribution in the heat storage tank, and to further reduce the number of heat medium temperature detectors installed compared to the related art. It is an object of the present invention to provide a method for estimating a temperature of a heat storage tank which is significantly reduced and an apparatus for estimating the temperature.

[Means for Solving the Problems] According to the present invention, in a method for estimating a temperature profile of a heat medium temperature distribution for estimating a temperature profile of a heat medium flowing from a first position to a second position in a heat storage tank, adjacent to each other. The current temperature of the heat medium located closer to the second position than the heat medium is regarded as the past temperature of the heat medium located closer to the first position than the adjacent heat medium. The current temperature of the heat medium located closer to the second position out of the heat medium adjacent to each other,
When given as the actual measured value of the heat medium temperature, a method for estimating a profile of the temperature distribution of the heat medium characterized by using the actual measured value as the current temperature is obtained.

Furthermore, according to the present invention, a heat storage tank for storing a heat medium, and first and second terminal tank heat medium temperature detections for actually measuring the temperatures of the heat medium located at the first and second positions of the heat storage tank, respectively. A heating medium, one or more intermediate heating medium temperature detectors for measuring the temperature of the heating medium located between the first and second positions, and a load applied to the heating medium located at the first position. A load section flowing into the second position side, a heat source section cooling or heating the heat medium positioned in the second position side to flow into the first position side, and measuring a heat source flow rate flowing from the heat source section. A heat source flow measuring unit, a load flow measuring unit that measures a load flow flowing from the load unit, a flow difference calculating unit that calculates a flow difference per unit time between the heat source flow and the load flow, and a post-flow. An accumulative flow difference calculating unit for accumulating the difference to calculate an accumulative flow difference; There the first and second said storage tank based on the cumulative flow rate difference when exceeding the predetermined capacity
A flow direction determining unit that determines the flow direction of the heat medium between the positions, and when the flow direction is from the first position side to the second position side, the flow direction of the heat medium adjacent to each other The current temperature of the heat medium located on the second position side is estimated as the past temperature of the heat medium located on the first position side among the heat media adjacent to each other, and the flow direction is When moving from the second position side to the first position side, the current temperature of the heat medium located closer to the first position among the heat mediums adjacent to each other is changed to the temperature of the heat medium adjacent to the adjacent heat medium. A heat medium temperature estimating unit for estimating a past temperature of the heat medium located on the second position side from among the medium, and the heat medium temperature estimating unit estimated by the heat medium temperature estimating unit; First and second heat medium temperature detectors and the intermediate The temperature of the current local points to be actually measured by the medium temperature detector, profile estimator of the heat medium temperature distribution is obtained which is characterized by having the estimated temperature changing unit that changes with each measured value of current.

[Operation] The present invention focuses on the fact that the temperature of the heat medium at each point varies according to the flow direction of the heat medium itself.
That is, with respect to the flow direction of the heat medium, the heat medium temperature at one point in the past one point before is estimated as the current heat medium temperature at the present time, and the measured values of the heat medium temperatures at several points are: By always repeating the current temperature at that point in sequence, without actually measuring the temperature of the heat medium at all points one by one, correcting the estimated temperature at other points in sequence with the minimum measured point temperature. Become.

This makes it possible to perform estimation suitable for the temperature distribution of the heat medium having a discontinuous profile in the heat storage tank.

Example Next, an example of the present invention will be described with reference to the drawings.

In this embodiment, the conventional cold water tank 1 shown in FIG.
This will be described with reference to FIG.

First, as shown in FIG. 2, the chilled water tank 1 is composed of a plurality of water tank groups partitioned by a plurality of partition walls 11, 11,... Communicating with each other, and the capacity of each water tank group is not the same. Therefore, the cold water tank 1 composed of the plurality of water tank groups is regarded as one large vessel, and this is equally divided into 50 regardless of the plurality of water tank groups. The capacity per divided tank is WO, and 50 virtual water tanks numbered # 1 to # 50 are set in order from the low-temperature terminal tank (left side in the drawing) to the high-temperature terminal tank (right side in the drawing). Then, the low-temperature terminal tank heat medium temperature detector 8 and the high-temperature terminal tank heat medium temperature detector 9 are connected to the low-temperature terminal tank #.
1 and the high-temperature side terminal tank # 50, respectively, and furthermore, a plurality of intermediate heat medium temperature detectors 10 were installed every several to ten tanks according to the scale of the cold water tank 1.

Next, the procedure for estimating the temperature of the heat medium in the cold water tank 1 will be described with reference to the flowchart of FIG.

First, the primary chilled water flow rate WR and the load flow rate WL are measured by the primary and secondary chilled water flow meters 6, 7 (S1), and the tank flow rate WT is calculated from the difference (S2). Next, the cumulative value WS of the tank flow rate WT is calculated (S3), and the absolute value of the cumulative value WS is calculated as the capacity per tank.
The time point at which WO is reached is monitored (S4). Then, whether the accumulated value WS at this time is positive or negative is identified (S5). Positive (WS>
0) is that the primary chilled water flow rate WR is larger than the load flow rate WL, so that the water flow in the tank flows from the low-temperature side to the high-temperature side, so the current water temperature (Tk, O ),
The temperature (Tk−1, −1) of the immediately preceding water tank, that is, the water tank immediately before the temporary limit having the smaller number #, is regarded as the temperature (S6). Conversely, in the negative case (WS <0), since the load flow rate WL is larger than the primary chilled water flow rate WR, the water flow in the tank flows from the high-temperature side to the low-temperature side. The water flow temperature (Tk + 1,1) of the water tank before the temporary limit is regarded as the current water flow temperature (Tk, O) of each virtual water tank (S7). However, in the water tanks # 1,... 50 in which the low-temperature terminal tank heat medium temperature detector 8, the high-temperature terminal tank heat medium temperature detector 9 and the intermediate heat medium temperature detector 10 are installed, the temperature measured at the present time is , Water flow temperature (T1,0),... (T50,0) (S8).

In the present embodiment, 50 virtual water tanks are set. However, it is obvious that increasing or decreasing the number of virtual water tanks in accordance with the requirement of the profile accuracy of the temperature distribution is included in the gist of the present invention.

[Effects of the Invention] As described above, according to the present invention, even if the number of heat medium temperature detectors for detecting the temperature of the heat medium in the heat storage tank is reduced, the accurate heat storage state of the heat storage tank can be reduced. Because I can understand
The construction cost for installing the heat medium temperature detector can be reduced, the flexibility of the instrumentation construction can be improved, and the effective function of the heat storage tank can be positively exhibited.

[Brief description of the drawings]

1 is a flowchart showing a control procedure according to one embodiment of the present invention, FIG. 2 is a conceptual diagram of a virtual water tank according to the embodiment of FIG. 1, and FIG. 3 is a block showing a state of circulation of cold water in a cold water tank. FIG. 1 ... Chilled water tank, 2 ... Refrigerator, 3 ... Load device, 4 ...
Primary chilled water pump, 5… Secondary chilled water pump, 6… Primary chilled water flow meter, 7… Secondary chilled water flow meter, 8… Low temperature terminal bath heating medium temperature detector, 9… High temperature side terminal Tank heat medium temperature detector, 10 ... Medium heat medium temperature detector, 11 ... Partition wall.

Claims (2)

(57) [Claims] 1. A method for estimating a profile of a temperature distribution of a heat medium for estimating a temperature profile of a heat medium flowing from a first position to a second position in a heat storage tank, comprising the steps of: Considering the current temperature of the heat medium located on the second position side as the past temperature of the heat medium located on the first position side of the heat medium adjacent to each other, the heat medium adjacent to each other Wherein, when the current temperature of the heat medium located on the second position side is given as an actual measured value of the heat medium temperature, the actual measured value is used as the current temperature. Method for estimating the profile of the medium temperature distribution. 2. A heat storage tank for storing a heat medium, first and second terminal tank heat medium temperature detectors for actually measuring the temperatures of the heat medium located at first and second positions of the heat storage tank, respectively. One or more intermediate heat medium temperature detectors for actually measuring the temperature of the heat medium located between the first and second positions; and applying a load to the heat medium located at the first position side to produce the second heat medium temperature detector. A load section that flows into the position side; a heat source section that cools or heats the heat medium that is positioned in the second position side to flow into the first position side; and a heat source that measures the flow rate of the heat source that flows in from the heat source section. A flow rate measurement unit, a load flow rate measurement unit that measures a load flow rate flowing from the load unit, a flow rate difference calculation unit that calculates a flow rate difference per unit time between the heat source flow rate and the load flow rate, and the flow rate difference. An accumulative flow difference calculator for accumulating and calculating an accumulative flow difference; A flow direction determining unit that determines a flow direction of the heat medium between the first and second positions in the heat storage tank based on the accumulated flow rate difference when a predetermined capacity is exceeded; When moving from the position side to the second position side, the current temperature of the heat medium located at the second position side among the heat medium adjacent to each other is changed to the current temperature of the heat medium adjacent to the second position side. It is estimated from the past temperature of the heat medium located on the first position side, and when the flow direction is from the second position side to the first position side, the heat medium among the heat medium adjacent to each other The current temperature of the heat medium located on the first position side from
A heat medium temperature estimating unit for estimating a past temperature of the heat medium located closer to the second position than the heat medium adjacent to each other, and a current time of the heat medium estimated by the heat medium temperature estimator. An estimated temperature change unit that changes the current temperature of each point actually measured by the first and second heat medium temperature detectors and the intermediate heat medium temperature detector among the temperatures to actual measured values at the current time; An apparatus for estimating a profile of a temperature distribution of a heat medium, comprising: