JP2016035351A - Method and device for controlling heat source system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify control operation, and to achieve large energy reduction effect.SOLUTION: A heat source system control method for optimally controlling a heat source system 10 including an absorption refrigerating machine 11 for cooling a cold heat medium supplied to an air-conditioning facility of a building, and a cooling tower 12 for cooling cooling water supplied to the absorption refrigerating machine 11, includes a cooling water temperature control step of calculating an optimum set value of a cooling water inlet temperature from an outdoor air wet-bulb temperature measured at an installation place of the building with the usage of an approximation equation in which a correlation between the optimum set value of the cooling water inlet temperature of the cooling tower 12 minimizing an energy consumption amount of the building and the outdoor air wet-bulb temperature is simplified, and controlling the cooling water inlet temperature based on the optimum set value.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a heat source system control method and apparatus for optimally controlling a heat source system installed in a building.

  In buildings such as office buildings, the proportion of energy consumption by heat source systems related to air conditioning equipment is increasing, and energy conservation measures are becoming increasingly important. Therefore, conventionally, in this type of building, a technique for optimally controlling the heat source system has been widely adopted.

  As a conventional technique of this type, for example, in Patent Document 1, optimization calculation is performed to minimize and maximize the objective function in real time for all the many parameters, and the setting values of each parameter are optimized. The control method of the air-conditioning equipment to perform is described.

  In Patent Document 2, a highly efficient operation control function is created by multivariate analysis, the parameters to be calculated in real time are limited, the optimum value of the parameter is obtained, and the heat source system that performs control based on the optimum value is optimized. An operation control method and the like are described.

  Further, in Patent Document 3, table data for controlling the cooling water temperature and the cooling water flow rate from the outside air wet bulb temperature and the cooling load is created, and the corresponding cooling water temperature according to the outside air wet bulb temperature and the cooling load is set. A control method for a cooling water production apparatus that controls the cooling water flow rate as a set value is described.

JP 2004-053127 A JP 2006-275323 A JP 2011-226684 A

  However, the technique disclosed in Patent Document 1 has a problem that the calculation speed is slow because the calculation load is large. In addition, there is a problem that the reliability of the control is lacking in the calculation of the optimum value by the optimization calculation that minimizes and maximizes the objective function because it may be a local optimum solution.

  In the technique of Patent Document 2 described above, when performing multivariate analysis in order to create a high-efficiency operation control function, the number of parameters is insufficient, or the formulas of each variable deviate from the actual heat source system. In such a case, there is a problem that the accuracy of the high-efficiency operation control function is lowered and the possibility that the calculated result is not optimal is increased.

  Furthermore, problems common to the techniques of Patent Documents 1 to 3 described above are that there are many parameters and measurement points necessary for control, the control system is complicated, and the control method and control function are complicated. When introducing a heat source system, whether it is costly or time-consuming to modify a control panel, regardless of whether it is a new or existing system, or when the equipment is being refurbished or if the optimum control is not performed And the control function needs to be corrected. However, the correction also requires cost and time.

  The present invention has been made to solve the various problems described above, and aims to provide a heat source system control method and apparatus capable of simplifying control and obtaining a large energy reduction effect. It is.

  In order to achieve the above-described object, the present invention provides an absorption refrigerator that cools a cooling medium supplied to an air conditioning facility of a building, a cooling tower that cools cooling water supplied to the absorption refrigerator, In the heat source system control method for optimally controlling the heat source system comprising: a correlation between the optimum set value of the cooling water inlet temperature of the cooling tower and the outside air wet bulb temperature that minimizes the energy consumption of the building Using the simplified approximate expression, the optimum setting value of the cooling water inlet temperature is calculated from the outside wet bulb temperature measured at the installation location of the building, and the cooling water inlet temperature is controlled based on the optimum setting value. And a cooling water temperature control step.

  According to this configuration, the cooling water inlet temperature is controlled using an approximate expression of the optimum setting value of the cooling water inlet temperature of the cooling tower and the outside air wet bulb temperature that minimizes the energy consumption of the target building. Therefore, a large energy reduction effect can be obtained with certainty.

  The heat source system control method according to the present invention may further include a cooling water flow rate control step of controlling a cooling water flow rate of the cooling tower according to the load of the absorption chiller.

  According to this configuration, an even greater energy reduction effect can be obtained.

Further, in the heat source system control method according to the present invention, the approximate expression is as follows: T _CT = a × T _OWB when the cooling water inlet temperature is T _CT , the outdoor wet bulb temperature is T _OWB , and a and b are constants. A linear expression represented by + b is preferable.

  According to this configuration, the calculation load is small, the calculation speed can be increased, and the parameter (outside air wet bulb temperature) that needs to be measured can be reduced to one, thereby simplifying the control system. be able to.

  Further, the present invention provides an optimal heat source system comprising an absorption chiller that cools a cooling medium supplied to a building air conditioner, and a cooling tower that cools cooling water supplied to the absorption chiller. In the heat source system control device for controlling the temperature, an approximate expression that simplifies the correlation between the optimum setting value of the cooling water inlet temperature of the cooling tower and the outside air wet bulb temperature that minimizes the energy consumption of the building A control unit that calculates an optimum set value of the cooling water inlet temperature from the outside wet bulb temperature measured at the installation location of the building and controls the cooling water inlet temperature based on the optimum set value; It is characterized by being.

  According to this configuration, the cooling water inlet temperature is calculated using an approximate expression of the optimum setting value of the cooling water inlet temperature of the cooling tower and the outside air wet bulb temperature that minimizes the energy consumption of the target building. Since it is controlled, a large energy reduction effect can be obtained with certainty.

  The heat source system control device according to the present invention may be configured to control the cooling water flow rate of the cooling tower in accordance with the load of the absorption chiller.

  According to this configuration, an even greater energy reduction effect can be obtained.

Moreover, in the heat source system control apparatus according to the present invention, the approximate expression is as follows: T _CT = a × T _OWB when the cooling water inlet temperature is T _CT , the outdoor wet bulb temperature is T _OWB , and a and b are constants. A linear expression represented by + b is preferable.

  According to this configuration, the calculation load is small, the calculation speed can be increased, and the parameter (outside air wet bulb temperature) that needs to be measured can be reduced to one, thereby simplifying the control system. be able to.

  According to the present invention, the cooling water inlet temperature is controlled using an approximate expression of the optimum setting value of the cooling water inlet temperature of the cooling tower and the outside air wet bulb temperature that minimizes the energy consumption of the target building. Therefore, various excellent effects can be obtained, for example, a large energy reduction effect can be obtained with certainty.

It is the schematic which shows the heat source system in embodiment of this invention. In a heat source system in an embodiment of the invention, it is a figure showing a performance curve for every cooling water inlet temperature of a direct absorption absorption type cold / hot water machine (double effect). In the heat source system according to the embodiment of the present invention, (a) shows the relationship between the energy consumption and the cooling water inlet temperature when the load factor of the direct water absorption type chiller / heater (double effect) is 60% or more. It is a figure, (b) is a figure which shows the relationship between the energy consumption and cooling water inlet temperature in case the load factor of a direct absorption type | mold absorption / cooling water heater (double effect) is 50% or less. It is a figure which shows the correlation with the optimal setting value of a cooling water inlet temperature, and external air wet bulb temperature at the time of performing only cooling water temperature control in the heat source system in embodiment of this invention. It is a figure which shows the correlation with the optimal setting value of a cooling water inlet temperature, and external air wet bulb temperature at the time of performing cooling water temperature control and cooling water flow control simultaneously in the heat source system in embodiment of this invention. It is a flowchart which shows the method of controlling the cooling water inlet temperature of a cooling tower based on the optimal setting value of a cooling water inlet temperature in the heat source system in embodiment of this invention. In the heat source system in the embodiment of the present invention, (a) is a diagram showing a performance curve for each cooling water inlet temperature of the vapor absorption refrigeration machine, (b) is a cooling water inlet of the direct water absorption type cold / hot water generator 1. The figure which shows the performance curve for every temperature, (c) is a figure which shows the performance curve for every cooling water inlet_port | entrance temperature of the direct water absorption type cold / hot water generator 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, a heat source system 10 according to an embodiment of the present invention will be described with reference to FIG.

  The heat source system 10 includes an absorption chiller 11 that cools cold water supplied to a building air conditioner (not shown), and a cooling tower 12 that cools cooling water supplied to the absorption chiller 11. I have.

  A cold water pipe 13 is disposed between the absorption refrigerator 11 and the air conditioning equipment. The chilled water pipe 13 is provided with a chilled water pump 14 in the vicinity of the upstream side of the absorption chiller 11 in the direction of circulating chilled water (see the arrow in FIG. 1).

  A cooling water pipe 15 is disposed between the absorption refrigerator 11 and the cooling tower 12. The cooling water pipe 15 is provided with a cooling water pump 16 in the vicinity of the upstream side in the cooling water circulation direction (see the arrow in FIG. 1) of the absorption refrigerator 11. Further, a bypass pipe 17 is branched and provided in the cooling water pipe 15 so as to bypass the cooling tower 12, and a three-way electromagnetic valve 18 is provided at a junction of the bypass pipe 17 and the cooling water pipe 15.

  A cooling water flow rate sensor F1, a first cooling water temperature sensor T1, and a second cooling water temperature sensor T2 are arranged in the middle of the cooling water pipe 15. The cooling water flow rate sensor F <b> 1 is disposed upstream of the cooling water pump 16 in the cooling water circulation direction, and measures the flow rate of the cooling water flowing through the cooling water pipe 15. The first cooling water temperature sensor T <b> 1 is disposed downstream of the cooling tower 12 in the cooling water circulation direction, and measures the temperature of the cooling water flowing through the cooling water pipe 15. Based on the measurement result of the first cooling water temperature sensor T1, the fan of the cooling tower 12 is controlled. The second coolant temperature sensor T <b> 2 is disposed downstream of the three-way solenoid valve 18 in the coolant circulation direction, and measures the temperature of coolant flowing through the coolant pipe 15. Based on the measurement result of the second coolant temperature sensor T2, the three-way solenoid valve 18 is controlled to be switched.

Outside the building, an outside air sensor P for measuring outside air conditions such as outside air temperature and relative humidity is arranged, and a measurement result by the outside air sensor P is transmitted to the control unit 19. Control unit 19, based on the measurement result of the outside air sensor P, and controls the set value T _SP of the cooling water inlet temperature of the cooling tower 12.

  Next, referring to FIGS. 2 to 6 in addition to FIG. 1, a method for controlling the heat source system 10 according to the embodiment of the present invention will be described.

  First, only the cooling operation is performed for the energy consumption of the heat source system 10 for each precondition input by combining a plurality of outdoor air conditions at the installation location of the building and a plurality of load conditions of the absorption refrigerator 11 respectively. Perform a simulation.

  In this example, as shown in Table 1, as the outside air conditions, six outside air temperatures of 10 ° C., 15 ° C., 20 ° C., 25 ° C., 30 ° C., 35 ° C., and 30%, 45%, 60 %, 75%, and 90% relative humidity are used, respectively, and the load conditions are 10% to 10% and 10% load factor, respectively. For each of the 300 preconditions that are input in combination with these conditions, the LCEM (Life Cycle Energy Management) tool provided by the Ministry of Land, Infrastructure, Transport and Tourism is performed while controlling the cooling water temperature control and cooling water flow rate control. Use to simulate energy consumption.

At this time, in the object in the LCEM, the direct absorption absorption chiller / heater (double effect) is selected as the absorption refrigeration unit 11, and the cooling tower 12 and the chilled water pump 14 are matched to the specification of the absorption refrigeration unit 11. And each specification of the cooling water pump 16 is selected, and those data are respectively input to the object in LCEM. The detailed specifications of the absorption chiller 11, the cooling tower 12, the chilled water pump 14, and the cooling water pump 16 input in this embodiment are shown in Table 2, and the selected direct absorption chiller / heater ( FIG. 2 shows performance curves for each cooling water inlet temperature (12 ° C., 16 ° C., 20 ° C., 24 ° C., 28 ° C., 32 ° C.). Here, the primary energy conversion coefficient is 9.76 MJ / kWh (electric power) and 45 MJ / m ³ (gas). In addition, in this specification, primary energy conversion value is used for energy consumption.

  Next, eleven values (see the top row in Table 3) obtained by changing the set value of the cooling water inlet temperature every 12 ° C. between 12 ° C. and 32 ° C. are input to the objects in the LCEM, respectively. The fan of the cooling tower 12 is controlled by the measurement result of the first cooling water temperature sensor T1 and the three-way solenoid valve 17 is switched by the measurement result of the second cooling water temperature sensor T1 so that the cooling water inlet temperature becomes the set value. Control (cooling water temperature control). And while performing cooling water temperature control in this way, the energy consumption of the whole heat source system 10 is simulated, compared, and evaluated. At this time, as shown in Table 3, each of the cooling water pump 16 and the cooling water pump 14 is set to constant flow control, and the lower limit setting value of the cooling water flow rate is set to the rating (100%) and absorbed. The cold water outlet temperature of the type refrigerator 11 is set to 7 ° C.

As a result of this simulation, when the load factor of the absorption chiller 11 is 60% or more, as shown in FIG. 3A, the total energy consumption is minimized at the lowest cooling water inlet temperature, In addition, when the load factor of the absorption chiller 11 is 50% or less, as shown in FIG. 3B, the total energy consumption amount when the cooling water inlet temperature is not a lowest value but a certain value. Minimal. As a result, the outdoor wet bulb temperature T _OWB is extracted as a parameter having the strongest correlation with the optimum set value T _CT of the cooling water inlet temperature of the cooling tower 12 that minimizes the energy consumption of the heat source system 10. And, there is a correlation as shown in FIG. 4 between the outside wet bulb temperature T _OWB and the optimum set value T _CT of the cooling water inlet temperature, and the optimum set value T _CT of the cooling water inlet temperature is It is obtained by an approximate expression expressed by the following expression.

T _CT = 0.747 × T _OWB +10.874

  Further, in addition to the cooling water temperature control, as shown in Table 4, the cooling water pump 16 is subjected to variable flow control (INV control), and the lower limit setting value of the cooling water flow is set to 50%, 60%, 70% of the rating, While changing the flow rate to 80% and 100% and controlling the cooling water flow rate, the energy consumption of the entire heat source system 10 is simulated, compared, and evaluated.

As a result of this simulation, as in the case where only the cooling water temperature control is performed, there is a correlation as shown in FIG. 5 between the optimum set value T _CT of the cooling water inlet temperature and the outside wet bulb temperature T _OWB . The optimum set value T _CT of the cooling water inlet temperature is obtained by an approximate expression expressed by the following linear expression.

T _CT = 0.742 × T _OWB +1.766

As described above, the optimum set value T _CT of the cooling water inlet temperature and the outside air are controlled both in the case where only the cooling water temperature control is performed and in the case where both the cooling water temperature control and the cooling water flow rate control are performed simultaneously. A correlation that is simplified by an approximate expression of a linear expression such as the following expression is established between the wet bulb temperature T _OWB .

T _CT = a × T _OWB + b
Here, a and b are constants.

Therefore, the optimum set value _TCT of the cooling water inlet temperature of the cooling tower 12 is determined by the approximate expression, and the cooling water inlet temperature is controlled based on the optimum set value _TCT .

Specifically, as shown in FIGS. 1 and 6, first, the control unit 19 receives the measurement result of the outside air wet bulb temperature by the outside air sensor P (see S1 in FIG. 6), and uses the approximate expression. Then, the optimum set value _TCT of the cooling water inlet temperature is calculated (see S2 in FIG. 6).

Thereafter, in the next step S3, the control unit 19 determines whether the calculated optimum setting value T _CT of the cooling water inlet temperature is equal to or lower than the lower limit value _TL of the cooling water inlet temperature at which the absorption chiller 11 can be operated. Judge whether.

As a result, when it is determined that the optimum set value T _CT of the cooling water inlet temperature is equal to or lower than the lower limit value _TL of the cooling water inlet temperature at which the absorption chiller 11 can be operated, the process proceeds to step S4 and the control unit 19 to set the lower limit T _L of the cooling water inlet temperature to the cooling water inlet temperature T _SP.

On the other hand, if it is determined in step S3 that the optimum set value T _CT of the cooling water inlet temperature is not less than or equal to the lower limit value _TL of the cooling water inlet temperature at which the absorption chiller 11 can be operated, go to step S5. Then, the control unit 19 sets the optimum set value T _CT of the cooling water inlet temperature calculated by the approximate expression as the cooling water inlet temperature T _SP .

Then, based on the setting value T _SP of the cooling water inlet temperature set in step S4 or step S5, it controls the cooling water inlet temperature of the cooling tower 12.

  According to the embodiment of the present invention described above, since the cooling water inlet temperature is controlled by the approximate expression of the optimum setting value of the cooling water inlet temperature and the outside air wet bulb temperature that minimizes the energy consumption amount, A reduction effect can be obtained with certainty.

  Further, since the approximate expression is a simple linear expression, the calculation load is small and the calculation speed can be increased. Furthermore, since the cooling water inlet temperature is controlled by one parameter (outside air wet bulb temperature) and the parameter that needs to be measured can be minimized, the control system can be simplified. Further, when this control system is introduced into an existing system, the control panel and the like can be easily modified, and the system introduction work can be simplified. Furthermore, since it is a linear expression for one parameter, there is no sudden change in the lower limit set value of the cooling water inlet temperature, and control stability can be achieved.

  In addition, when calculating the approximate expression, since the energy simulation is performed by covering various possible outside air conditions and load conditions and changing the set value of the cooling water inlet temperature in various ways, the reliability of the approximate expression is high. In addition, operation near the global optimum solution can be realized.

  In addition, by arbitrarily changing the constants a and b of the approximate expression, the deviation between the previous simulation result and the optimum value of the actual system is eliminated, and the operation close to the optimum value of the actual system is performed. Can be realized. Furthermore, it is possible to easily cope with changes in the characteristics of equipment due to introduction into similar systems, equipment updates, and equipment deterioration.

In the above-described embodiment of the present invention, the approximate expression is obtained based on the simulation result under a specific condition in one example. However, as shown in Table 5, (1) to (10) Even if an approximate expression between the optimum setting value T _CT of the cooling water inlet temperature and the outside air wet bulb temperature T _OWB is obtained based on the simulation result under other conditions, it is expressed by an approximate expression of a linear expression as follows: be able to. Here, in the column of the cooling tower capacity in Table 5, “without margin” means that a cooling tower equal to the rated specification of the absorption chiller is selected, and “with margin” means that the absorption chiller This indicates that a cooling tower with a capacity of about 20 to 40% larger than the rated specification was selected. Moreover, Fig.7 (a) is every cooling water inlet temperature (12 degreeC, 16 degreeC, 20 degreeC, 24 degreeC, 28 degreeC, 32 degreeC) of a vapor | steam absorption refrigerator (refer condition (1) in Table 5). FIG. 7 (b) shows the performance curve, and FIG. 7 (b) shows the cooling water inlet temperature (12 ° C., 16 ° C., 20 ° C., 24 ° C., 28) of the direct absorption type cold / hot water generator 1 (see condition (2) in Table 5). FIG. 7 (c) shows the cooling water inlet temperature (12 ° C.) of the direct absorption type cold / hot water generator 2 (see conditions (3) to (10) in Table 5). , 16 ° C, 20 ° C, 24 ° C, 28 ° C, 32 ° C).

Approximation formula in the case of condition (1): T _CT = 0.7459 × T _OWB +10.516
Approximation formula in the case of condition (2): T _CT = 0.7522 × T _OWB +10.783
Approximation formula in the case of condition (3): T _CT = 0.7463 × T _OWB +10.608
Approximation formula in the case of condition (4): T _CT = 0.7455 × T _OWB +10.666
Approximation formula in the case of condition (5): T _CT = 0.734 × T _OWB +11.084
Approximation formula for condition (6): T _CT = 0.7315 × T _OWB +11.249
Approximation formula in the case of condition (7): T _CT = 0.7392 × T _OWB +10.825
Approximation formula in the case of condition (8): T _CT = 0.7428 × T _OWB +10.645
Approximation formula in the case of condition (9): T _CT = 0.7367 × T _OWB +10.915
Approximation formula in the case of condition (10): T _CT = 0.7402 × T _OWB +10.632

In each of the above-described embodiments, all of the approximate expressions are expressed by linear expressions. This is between the optimum set value T _CT of the cooling water inlet temperature and the outdoor wet bulb temperature T _OWB in the present invention. It is not intended to limit the approximate expression to a linear expression. That is, the approximate expression between the optimum set value T _CT of the cooling water inlet temperature and the outside air wet bulb temperature T _OWB can be expressed by a single expression such as a quadratic expression, a cubic expression, a polynomial, etc. It may be a formula.

  Moreover, since the above-mentioned description of embodiment of this invention has demonstrated the preferred embodiment in the heat-source system control method which concerns on this invention, and its apparatus, various technically preferable restrictions are attached | subjected. In some cases, the technical scope of the present invention is not limited to these embodiments unless specifically described to limit the present invention. That is, the above-described components in the embodiment of the present invention can be appropriately replaced with existing components and the like, and various variations including combinations with other existing components are possible. The description of the embodiment of the present invention described above does not limit the contents of the invention described in the claims.

DESCRIPTION OF SYMBOLS 10 Heat source system 11 Absorption-type refrigerator 12 Cooling tower 19 Control part

Claims (6)

A heat source for optimally controlling a heat source system comprising: an absorption refrigerator that cools a cooling medium supplied to an air conditioning facility of a building; and a cooling tower that cools cooling water supplied to the absorption refrigerator In the system control method,
Measured at the installation location of the building using an approximate expression that simplifies the correlation between the optimum setting value of the cooling water inlet temperature of the cooling tower and the outside air wet bulb temperature to minimize the energy consumption of the building. A heat source system control method comprising: a cooling water temperature control step of calculating an optimum set value of the cooling water inlet temperature from the outside air wet bulb temperature, and controlling the cooling water inlet temperature based on the optimum set value .   The heat source system control method according to claim 1, further comprising a cooling water flow rate control step of controlling a cooling water flow rate of the cooling tower in accordance with a load of the absorption refrigerator. The approximate expression is a linear expression represented by T _CT = a × T _OWB + b, where T _CT is the cooling water inlet temperature, T _{OWB is} the outdoor wet bulb temperature, and a and b are constants. The heat source system control method according to claim 1 or 2. A heat source for optimally controlling a heat source system comprising: an absorption refrigerator that cools a cooling medium supplied to an air conditioning facility of a building; and a cooling tower that cools cooling water supplied to the absorption refrigerator In the system controller,
Measured at the installation location of the building using an approximate expression that simplifies the correlation between the optimum setting value of the cooling water inlet temperature of the cooling tower and the outside air wet bulb temperature to minimize the energy consumption of the building. A heat source system control device comprising: a control unit that calculates an optimum set value of the cooling water inlet temperature from the outside air wet bulb temperature that has been set, and controls the cooling water inlet temperature based on the optimum set value.   The heat source system control device according to claim 4, wherein the heat source system control device is configured to control a cooling water flow rate of the cooling tower in accordance with a load of the absorption refrigerator. The approximate expression is a linear expression represented by T _CT = a × T _OWB + b, where T _CT is the cooling water inlet temperature, T _{OWB is} the outdoor wet bulb temperature, and a and b are constants. The heat source system control apparatus according to claim 4 or 5.

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