JP5506460B2 - Cooling system - Google Patents

Description

  The present invention relates to a cooling system that cools a heat medium using solar heat, and more particularly, to a cooling system capable of optimal control in consideration of energy saving and low operation cost.

  As a heat collection system using solar heat, there are technologies shown in Patent Document 1 and Patent Document 2. In the technique of Patent Document 1, a solar heat collector that collects solar heat energy and applies the collected solar energy to a heat medium, a heat medium that has become a high temperature due to heat collection by the solar heat collector, and a water supply tank Heat exchange is performed between the first heat exchanger that performs heat exchange with the feed water to be transferred, and the feed water that has become hot due to heat exchange in the heat exchanger and the hot working medium. And a second heat exchanger for generating steam for the process.

  Moreover, in the technique of patent document 2, while using solar heat directly for the heating and concentration of absorption liquid, it can drive | operate without requiring the heat source which heats regenerators, such as a burner, and according to the weather condition etc. A solar heat collector tube that directly introduces and heats diluted absorption liquid for stable air-conditioning effect and miniaturization by detecting the heating situation of the absorption liquid due to changing solar heat and automatically operating the auxiliary regenerator An absorption-type air conditioner having a flushing regenerator that concentrates by flushing an absorption liquid heated by the solar heat collecting tube is shown.

JP-A 63-183346 JP 2001-82823 A

  However, in Patent Document 1, solar heat is used in the daytime to generate process steam, and hot water is made by a hot water boiler during bad weather or at night. Fuel (gas) of the hot water boiler Although the cost is reduced, it does not depend on the optimal control for reducing the operating cost of the entire system, which is the sum of the fuel (gas) cost and the power cost of the pump and the like.

  Moreover, in patent document 2, since it absorbs liquids, such as a lithium bromide, as a heat carrier, it heats by flowing in piping, a large amount of absorption liquid is required, handling and management are troublesome, and cost becomes high. Also, if boiling occurs in the absorbing solution during heating, the pressure may increase abnormally and cause a back flow, making temperature management difficult. And when the temperature of the absorption liquid heated with the solar heat collecting tube is low like patent document 1, it heats with heat sources, such as a burner, but the system which totaled fuel costs, such as a burner, and electric power expenses, such as a pump It does not depend on optimal control to reduce overall operating costs.

  In view of the above-described conventional problems, the present invention provides a cooling system that minimizes operating costs when cooling a heat medium using solar heat as an energy source.

In order to solve the above problems, the present invention provides a cooling system for cooling a heat medium load.
A solar collector that collects solar thermal energy;
An absorption refrigerator that uses the heat collected by the solar heat collector as drive energy;
A cooling tower for cooling the cooling water to the absorption refrigerator,
An outside air condition detecting means for detecting an outside air condition such as a specific enthalpy of outside air or a wet bulb temperature of outside air;
A heat collection amount detecting means for detecting a heat collection amount of the solar heat collector;
A load detecting means for detecting the cooling load of the heat medium;
A cooling water pump driven by an inverter or a cooling tower fan driven by an inverter;
A control device for controlling each of the above-mentioned parts ;
Extracting at least one set value of the inverter frequency of the cooling water pump or the cooling tower or the number of the absorption chillers from the outside air conditions, the amount of collected heat of the solar collector, and the parameter value of the cooling load It has a database that stores control tables,
The detected ambient conditions above, collecting heat of solar heat collector, in accordance with the cooling load, extracts the set value of each inverter frequency or the number of operating units of the absorption chiller from the database, this setting value A cooling system for controlling the operation of each of the inverters or the operation / stop of the absorption refrigerator.

  Further, in the cooling system described above, the database is a control table, and the control table is repeatedly calculated by changing a control target value of an outside air condition, a solar heat collection amount, and a cooling load using a simulation. The frequency of each of the inverters or the operating number of the absorption chillers with the smallest overall energy consumption is provided as a set value.

Further, in the cooling system described above, the simulation may be performed by calculating the steam consumption of the absorption chiller based on the relational expression of the steam consumption obtained by the cycle simulation or the relational expression of the steam consumption of the absorption chiller. It is a simulation provided with the step to calculate.

In the cooling system described above, the simulation is a simulation including a step of calculating a cooling water flow rate and a power consumption of the cooling water pump from at least a frequency of electric power input to the cooling water pump. To do.

In the cooling system described above, the simulation calculates the air volume and power consumption from the frequency of the electric power input to the fan of the cooling tower, and cools from the outside air condition, the air volume, the flow rate of the cooling water, and the cold water return temperature. The simulation includes a step of calculating the water temperature.

  Further, in the cooling system described above, the heat medium derived from the solar heat collector is further separated into a liquid and a gas, the gas is supplied to the absorption chiller as drive energy, and the liquid is supplied to the solar heat collector. A gas-liquid separator that returns to the refrigerator, and the controller calculates the amount of solar heat collected based on the temperature and pressure of the gas separated by the gas-liquid separator and the temperature of the liquid returned from the absorption refrigerator. It is characterized by.

  Further, the cooling system described above further includes a pyranometer for measuring the amount of solar radiation, and the control device calculates the amount of solar heat collected based on the measured amount of solar radiation and time. .

  ADVANTAGE OF THE INVENTION According to this invention, the energy consumption cost at the time of operation | movement of the cooling system which cools a thermal medium using solar heat as an energy source can be reduced.

It is a system configuration figure of a 1st embodiment of the present invention. It is an image figure which calculates | requires an optimal setting value. It is a specific block diagram of a control table. It is a creation method flowchart of a control table. It is a flowchart of the simulation calculation of FIG. It is the operation | movement flowchart which showed the optimization control method. It is a system configuration figure of a 2nd embodiment of the present invention. It is a system configuration figure of a 3rd embodiment of the present invention. It is a flowchart which calculates the amount of solar heat collection from the amount of direct solar radiation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a diagram showing a system configuration of a cooling system according to the first embodiment of the present invention. Reference numeral 1 denotes a solar heat collector, in which water flows as a heat medium, water introduced from the lower inlet is heated by solar heat, and a liquid mixture of liquid (hot water) and gas (steam) from the upper outlet. Is derived. The mixed fluid of liquid and gas flows into the gas-liquid separator 2 and is separated into liquid and gas. Reference numeral 80 denotes a control device that executes the control described below for the entire system. Reference numeral 201 denotes a temperature sensor of the separated gas, reference numeral 231 denotes a pressure sensor thereof, and reference numeral 201 denotes a temperature sensor of the return liquid of the absorption refrigerator (described later). In the control device 80, the amount of solar heat collected by the solar heat collector 1 is calculated based on the measured values of the temperature sensors 201 and 202 and the pressure sensor 231.

  3 is a pump that sends liquid water (heat medium) separated by the gas-liquid separator 2 to the solar heat collector 1 and is driven by an inverter 103. The flow rate of the heat medium flowing through the solar heat collector 1 is controlled by changing the frequency of the inverter 103. The heat medium flowing through the solar heat collector 1 is controlled so as to efficiently take in the heat amount so that the flow rate is increased when the heat collection amount is large and the flow rate is decreased when the heat collection amount is small.

  31, 32, and 33 are absorption refrigerators, and steam separated by the gas-liquid separator 2 is used as driving energy. 4 is a boiler 4 in which steam is produced with gas, which operates when the amount of steam produced by solar heat is less than the amount of steam required by the absorption chillers 31, 32, 33, and produces insufficient steam. In the control device 80, the gas amount of the boiler is controlled according to the heat collection of the solar heat collector 1.

  10 is a cooling tower that is installed side by side and cools the cooling water of the absorption chillers 31, 32, 33. The number of revolutions of the fan 10a of each cooling tower is changed by the inverter 110, and the amount of air is changed. The temperature is controlled. 21, 22, and 23 are cooling water pumps that send cooling water to the absorption chillers 31, 32, and 33, respectively, and are driven by inverters 121, 122, and 123 that change the flow rates of the cooling water.

  Reference numerals 41, 42, and 43 denote chilled water pumps that send chilled water from a chilled water tank (described later) to the absorption refrigerators 31, 32, and 33, respectively. .

  Reference numeral 50 denotes a cold water tank in which cold water cooled by the absorption refrigerators 31, 32, 33 is stored. The cold water in the cold water tank 50 is sent to the load 70 which is a heat medium by the cold water secondary pump 60, heated by the consumption of the cold heat in the load 70, and returned to the cold water tank 50. Reference numerals 203 and 204 denote temperature sensors at the inlet and outlet of the load 70, and 221 denotes a flow rate sensor. Based on the measurement values of the temperature sensors 203 and 204 and the flow rate sensor 221, the cooling load of the load 70 is calculated. Connected to the cold water secondary pump 60 is an inverter 160 that changes the flow rate of the cold water sent to the load.

  The frequency of the inverter 160 controls the rotation of the chilled water secondary pump 60 so that the temperature difference between the temperature sensor 203 and the temperature sensor 204 is constant. Further, the inverters 141, 142, and 143 control so that the total flow rate of cold water sent to the absorption chillers 31, 32, and 33 is the same as the flow rate of cold water sent to the load 70 by the cold water secondary pump 60. Since the frequency of the inverters 141, 142, 143 and the flow rate of the cold water sent to the absorption chillers 31, 32, 33 have a certain relationship (substantially proportional relationship), the relationship is controlled during the trial operation by the control device 80. The frequency is controlled according to the relationship. At that time, the relationship between the frequency of the inverters 141, 142, 143 and the power consumption of the chilled water pumps 41, 42, 43 is also obtained in the control device 80.

  205 is a temperature sensor that measures the temperature of the outside air, and 211 is a humidity sensor that measures the humidity of the outside air. Based on the measured values of the temperature sensor 205 and the humidity sensor 211, the wet bulb temperature (outside air condition) of the outside air is calculated. Although the wet bulb temperature will be described here, since the wet bulb temperature and the specific enthalpy have a fixed relationship, the specific enthalpy may be used for the outside air condition instead of the wet bulb temperature.

  In the above-described configuration, this embodiment is configured to extract a set value 80b of a database (control table, approximate curve, or the like) 80a created in advance in the control device 80, and supply it to each part of the system for operation. is there. The set value is configured with a value that minimizes the energy consumption of the entire system. FIG. 2 is a diagram showing an image for obtaining a set value. When the outside wet bulb temperature (Y-axis), cooling load (X-axis), and the amount of solar heat collected (Z-axis) are determined, the set values indicated by the black circles at the intersections of the broken lines are determined, and the values are controlled.

  The set value 80b of the control table 80a as a database includes three types, that is, the number of absorption chillers to be operated, the inverter frequency of the cooling tower fan 10a, and the inverter frequencies of the cooling water pumps 21 to 23. This is not a typical setting value, but a final setting value that allows direct control of the system. Therefore, the inverter can be directly controlled without converting the extracted set value. FIG. 3 is a diagram showing a specific configuration of the control table 80a. The control table 80a has, as input conditions, the outside wet bulb temperature and cooling load on the horizontal axis and the amount of solar heat collected on the vertical axis, and the above-mentioned three kinds of set values are provided at the intersections.

  The set value 80b is calculated in advance by calculating the power consumption and gas consumption of the entire system when the amount of solar heat collection, the outside wet bulb temperature (outside air conditions), and the cooling load are changed by simulation calculation described later. A value that minimizes running cost is required from consumption and unit price.

  FIG. 6 is an operation flowchart showing an optimization control method for the entire system based on the set value 80b of the control table 80a.

  First, the measured values of the temperature sensors 201, 202, 203, 204, 205, the flow sensors 221, 222, the humidity sensor 211, and the pressure sensor 231 are acquired by the control device 80 for the operating system (step 730). Next, the controller 80 calculates the amount of heat collected by the solar heat collector 1 based on the measured values of the temperature sensor 201, the temperature sensor 202, the pressure sensor 231, and the flow rate sensor 222. The cooling load is calculated from the measured values of the temperature sensor 203, the temperature sensor 204, and the flow sensor 221, and the wet bulb temperature of the outside air is calculated from the measured values of the temperature sensor 205 and the humidity sensor 211 (step 731).

  Next, referring to the control table 80a of FIG. 3, the number of operating the absorption refrigerators 31, 32, 33 corresponding to the amount of collected solar heat, the wet bulb temperature of the outside air, and the cooling load, the cooling tower 10 The set value 80b of the frequency of the inverter 110 of the fan 10a and the frequency of the inverters 121, 122, 123 of the cooling water pumps 21, 22, 23 is extracted (step 732). Then, the number of operating the absorption chillers 31, 32, 33 of the extracted set value 80b, the frequency of the inverter 110 of the fan 10a of the cooling tower 10, the inverters 121, 122, 122 of the cooling water pumps 21, 22, 23, The system controls the system by sending 123 frequencies to each device (step 733).

  By this control, the entire system is operated with the minimum running cost.

  In addition, about the amount of solar heat collection, the wet-bulb temperature of external air, and a cooling load, you may create and use a predicted value from the time series data until now.

  Next, a method for generating the control table 80a will be described with reference to the flowchart of FIG. The control table 80a is generated in advance by a device (not shown) different from the system shown in FIG. 1 based on the specifications of the input and its output, such as a design drawing of the system.

  The flowchart of FIG. 4 is a flowchart for determining a set value of one point indicated by a black circle in FIG. 2 or an intersection point in FIG. 3, and the set values of all the intersection points are determined by repeated calculation. In this embodiment, the running cost is described as the evaluation function, but other evaluation functions may be used. By executing the flowchart of FIG. 4 once, one intersection of the control table of FIG. 3 is determined, and by repeating this, all the intersections of the control table of FIG. 3 are determined.

  In step 401, the amount of solar heat collection, the wet bulb temperature of the outside air, and the cooling load corresponding to one intersection point to be determined in the control table of FIG. 3 are input. By repeating Step 402 to Step 406, the number of operating absorption refrigerators that can be operated, the frequency of the inverter 110 of the cooling tower 10, and the frequency of the inverters 121, 122, and 123 of the cooling water pumps 21, 22, and 23 can be obtained. All the combinations are sequentially set, and when calculation of all the combinations is completed, the process proceeds from step 405 to step 407. Note that the frequencies of the inverters 110, 121, 122, and 123 are set to values at certain constant intervals.

  In step 403, the amount of solar heat collected, the temperature of the wet bulb of the outside air, the cooling load, the number of operating refrigerators, the frequency of the inverter 110 of the cooling tower 10, the frequency of the inverters 121, 122, 123 of the cooling water pumps 21, 22, 23 The frequency is input, and the power consumption and gas consumption of the entire system are calculated by simulation calculation. This simulation calculation will be described later.

  In step 404, the evaluation function is calculated and compared. First, the running cost, which is an evaluation function, is calculated using the power unit price and the gas unit price. Next, the evaluation functions are compared. When the value of the previous evaluation function is not stored (first calculation, etc.), the combination of the number of operating refrigerators at that time, the frequency of the inverters 110, 121, 122, 123, and the value of the evaluation function are stored. If the value of the previous evaluation function is stored (from the second time on), if the value of the evaluation function calculated this time is smaller than the stored previous evaluation function, The combination of the number of operating machines and the frequency of the inverters 110, 121, 122, 123 and the value of the evaluation function are updated and stored. If the value is larger, the previous evaluation function is left as it is. In the above process, the storage process is not performed when the constraint conditions of the device such as the operation range of the device are satisfied.

  When calculation of all the settings is completed, the combination of the number of operating refrigerators stored in step 404 (minimizing the evaluation function) and the frequency of inverters 110, 121, 122, 123 (absorption refrigerator) in step 407 3 types, the inverter frequency of the cooling tower fan 10a, and the inverter frequency of each cooling water pump) are stored as set values at the intersection of the control table 80a of FIG. In this way, the set value 80b that minimizes the energy consumption of the system is stored.

  In the above, the value of the evaluation function was calculated for every case of a certain value, and the optimal combination of setting values that minimizes the evaluation function was obtained. However, the steepest descent method, quasi-Newton method, sequential quadratic programming An optimization algorithm such as a method may be used.

  FIG. 5 is a flowchart illustrating in detail the simulation calculation in step 403 of FIG. In the simulation calculation of FIG. 5, the power consumption and gas consumption are obtained, and the running cost is calculated using the unit price of power and gas. Next, the detailed flowchart of FIG. 5 will be described.

  In step 501, the amount of solar heat collected, the wet bulb temperature of the outside air, the cooling load, the number of operating refrigerators, the frequency of the inverter 110 of the cooling tower 10, the frequencies of the inverters 121, 122, 123 of the cooling water pumps 21, 22, 23 Enter.

  In step 502, the power consumption of the cold water pump is calculated based on the input. That is, the flow rates of the chilled water pumps 41, 42, and 43 are obtained from the cooling load and the number of operating refrigerators. The frequencies of the inverters 141, 142, and 143 are obtained from the flow rates of the cold water pumps 41, 42, and 43. The power consumption of the chilled water pumps 41, 42, and 43 is obtained from the frequencies of the inverters 141, 142, and 143. Since there is a fixed relationship between the inverter frequency, flow rate, and power consumption, it is obtained during trial operation. Or, (Formula 1), (Formula 2), (Formula 3), pump discharge pressure characteristics and flow path, where the flow rate, pressure and power of the pump are proportional to the 1st, 2nd and 3rd powers of the inverter frequency, respectively. It may be obtained by using the balance of resistance characteristics (Equation 4) and the power consumption characteristic of the pump (Equation 5).

  Hereinafter, the calculation of the inverter frequency, flow rate, power consumption, etc. of the pump is performed in the same manner, and the description is omitted. Also, since the fan is calculated in the same way, the description is omitted.

  In step 503, the power consumption and cooling water flow rate of the cooling water pump are calculated. That is, the flow rate of cold water flowing through the refrigerators 31, 32, 33 and the power consumption of the cooling water pump are calculated from the number of operating refrigerators and the frequencies of the inverters 121, 122, 123.

  In step 504, the forward temperature of the cooling water is set. Here, the forward temperature of the cooling water is the lower temperature of the cooling water (the temperature of the cooling water flowing from the cooling tower to the refrigerator), and the higher temperature is the return temperature of the cooling water (returning from the refrigerator to the cooling tower) The temperature of the cooling water).

  In step 505, the steam consumption, power consumption, and cooling water return temperature of the absorption chillers 31, 32, and 33 are obtained. The steam consumption of the absorption chillers 31, 32, and 33 is determined by the coolant temperature, the coolant flow rate, the cooling load, the coolant temperature, and the coolant flow rate. This relational expression is obtained in advance by cycle simulation and is calculated using this relational expression. Or, if the manufacturer of the absorption chiller has released the relational expression, the relational expression is used. Alternatively, the relational expression may be actually obtained by measurement. Since power consumption is almost constant, it is measured during the trial run and used. Then, the return temperature of the cooling water is obtained from the heat balance.

  In step 506, the power consumption of the cooling tower and the forward temperature of the cooling water are calculated. First, the air volume and power consumption of the cooling tower fan 10a are calculated from the frequency of the inverter 110. Since these have a certain relationship, they are obtained during trial operation. Next, the forward temperature of the cooling water is calculated from the return temperature of the cooling water calculated in step 505, the flow rate of the cooling water calculated in step 504, the wet bulb temperature of the outside air, and the air volume of the cooling tower fan 10a. The calculation is performed using (Equation 6) for calculating the exchange heat quantity in the cooling tower using the enthalpy standard overall volumetric heat transfer coefficient and (Equation 7) for the law of conservation of heat.

  If the steps 505 and 506 are repeatedly calculated several times, the flow temperature and return temperature of the cooling water converge and remain unchanged. If the flow converges at step 507, the flow proceeds to step 508. In step 508, the gas consumption amount in the boiler 4 is calculated in a converged state. The difference between the amount of steam necessary for the absorption refrigerator calculated in step 505 and the amount of steam that can be generated from the amount of solar heat collected is calculated, and the amount of steam generated by the boiler is calculated. Then, the gas consumption necessary to generate the steam amount is calculated.

  In step 509, the power consumption of the pumps 3, 5 and the cold water secondary pump 60 is calculated. Since the flow rate of water sent to the boiler by the pump 5 can be calculated from the amount of steam, the inverter frequency and power consumption of the pump 5 at that time are calculated. Moreover, since the flow volume of the water sent to the solar heat collector 1 is obtained from the amount of collected solar heat, the flow volume, inverter frequency, and power of the pump 3 at that time are calculated. Further, since the flow rate of the chilled water secondary pump 60 is obtained from the cooling load, the inverter frequency and power consumption at that time are calculated. In step 510, the power consumption and gas consumption calculated in steps 502 to 509 are totaled.

  With the above generation method of the control table 80a, the power consumption and gas consumption of the entire system can be calculated.

As described above, the number of operating refrigerators and the inverter frequency are minimized in the control table 80a in accordance with the outside air condition, the amount of solar heat collected and the state of the cooling load, so that the running cost (energy consumption) of the entire system is minimized. Is set.
(Second Embodiment)
FIG. 7 is a configuration diagram of a system according to the second embodiment of this invention. Here, a different part from 1st Embodiment is described. A liquid heat medium flows through the solar heat collector 1. High-pressure water or oil can be used as the liquid heat medium. In the solar heat collector 1, the heat medium is heated by solar heat. The heat medium is about 190 ° C. at the inlet of the solar heat collector 1 and about 200 ° C. at the outlet.

  The heated heat medium exchanges heat with water in the heat exchanger 7. The water heat-exchanged by the heat exchanger 7 becomes steam at about 180 ° C. and is sent to the absorption chillers 31, 32, 33. The amount of solar heat collected by the solar heat collector 1 is calculated based on the measured values of the temperature sensor 206, the temperature sensor 207, and the flow rate sensor 222.

  The pump 6 is a pump that circulates a heat medium in the solar heat collector 1 and is connected to an inverter 106. The flow rate of the heat medium flowing through the solar heat collector 1 is changed by changing the frequency of the inverter 106. The heat medium flowing through the solar heat collector 1 increases the flow rate when the amount of heat collection is large, and decreases the flow rate when the amount of heat collection is small.

  The portion of the load 70 does not have the cold water tank and the secondary pump of the first embodiment, and the cold water flows to the load through the forward header 81 and returns to the absorption chillers 31, 32, 33 through the return header 82. . The amount of heat of the load is calculated based on the measured values of the temperature sensors 208 and 209 and the flow rate sensor 223. The method for detecting and controlling the wet bulb temperature of the outside air is the same as that in the first embodiment.

According to this embodiment, since there is no cold water tank and secondary pump, the structure can be greatly simplified. Further, since the heat exchanger 7 separates the piping system of the solar collector 1 from the other piping systems and can independently manage the piping system, maintenance at the time of failure is facilitated. Moreover, since only the solar heat collector 1 and the heat exchanger 7 are circulated in the present embodiment, the amount of heat medium is small. Further, the amount of solar heat collected by the solar heat collector 1 is calculated based on the measured values of the temperature sensor 206, the temperature sensor 207, and the flow rate sensor 222, which are sensors arranged in the piping system of the solar heat collector 1. The amount of solar heat collected can be detected immediately after the start of system operation, and the rise of system control can be accelerated.
(Third embodiment)
FIG. 8 is a configuration diagram of a system according to the third embodiment of this invention. Here, a different part from 1st Embodiment is described.

  Direct solar radiation meter 250 measures the amount of direct solar radiation of the sun (measured from the amount of solar radiation and direct sunlight only from the range of the sun's photosphere). Here, the direct solar radiation meter will be described, but the direct solar radiation amount may be estimated from the total solar radiation amount measured by the global solar radiation meter. FIG. 9 is a flowchart for calculating the amount of solar heat collected from the amount of direct solar radiation.

  First, in step 531, the direct solar radiation amount and time, latitude, and longitude of the sun measured by the direct solar radiation meter 250 are input to the control device 80. For the time, enter the number of units in operation and the time of the control cycle to change the inverter frequency. Next, in step 532, the position of the sun is calculated from the time, latitude, and longitude. In the control device 80, the solar heat collection amount is calculated from the position of the sun, the direct solar radiation amount of the sun, and the characteristics of the solar heat collector 1. The detection of the outside air wet bulb temperature, the detection of the cooling load, and the operation control of the system are performed in the same manner as in the first embodiment.

  According to the present embodiment, the amount of solar heat collected is calculated from the amount of solar radiation, so even if the amount of solar radiation changes, the amount of solar heat collected can be quickly and accurately grasped, and the change in the amount of solar radiation can be promptly and accurately handled. Thus, the control of the entire system by the control device 80 can be promptly handled.

  DESCRIPTION OF SYMBOLS 1 ... Solar collector, 2 ... Gas-liquid separator, 4 ... Boiler, 10 ... Cooling tower, 10a ... Cooling tower fan, 21-23 ... Cooling water pump, 31-33 ... Absorption type refrigerator, 70 ... Cooling Load, 80 ... control device, 80a ... control table, 80b ... set value, 110 ... fan inverter, 121-123 ... cooling water pump inverter, 201 ... isolated gas temperature sensor, 202 ... absorption refrigerator Returning liquid temperature sensor, 231... Separated gas pressure sensor, 201, 202, 222, 231... Heat collection amount detection means, 205, 211 ... Outside air condition detection means, 203, 204, 221 ... Load detection means, 250. Pyranometer.

Claims (7)

In the cooling system for cooling the heat medium load,
A solar collector that collects solar thermal energy;
An absorption refrigerator that uses the heat collected by the solar heat collector as drive energy;
A cooling tower for cooling the cooling water to the absorption refrigerator,
An outside air condition detecting means for detecting an outside air condition such as a specific enthalpy of outside air or a wet bulb temperature of outside air;
A heat collection amount detecting means for detecting a heat collection amount of the solar heat collector;
A load detecting means for detecting the cooling load of the heat medium;
A cooling water pump driven by an inverter or a cooling tower fan driven by an inverter;
A control device for controlling each of the above-mentioned parts ;
Extracting at least one set value of the inverter frequency of the cooling water pump or the cooling tower or the number of the absorption chillers from the outside air conditions, the amount of collected heat of the solar collector, and the parameter value of the cooling load It has a database that stores control tables,
The detected ambient conditions above, collecting heat of solar heat collector, in accordance with the cooling load, extracts the set value of each inverter frequency or the number of operating units of the absorption chiller from the database, this setting value A cooling system for controlling the operation of each of the inverters or the operation / stop of the absorption refrigerator. The cooling system according to claim 1,
The database is a control table, and the control table is repeatedly calculated by changing the control target value of the outside air condition, the solar heat collection amount, and the cooling load by using a simulation, and each of the above-mentioned respective systems has the smallest energy consumption. cooling system, wherein a number of operating inverters of the frequency or the absorption refrigerator is provided as a setting value. The cooling system according to claim 2, wherein
The simulation is a simulation including a step of calculating the steam consumption of the absorption refrigeration machine based on the relational expression of the steam consumption obtained by the cycle simulation or the relational expression of the steam consumption of the absorption chiller. A cooling system featuring. The cooling system according to claim 2 or 3,
The said simulation is a simulation provided with the step which calculates the cooling water flow volume and the power consumption of a cooling water pump from the frequency of the electric power input into a cooling water pump at least. In the cooling system in any one of Claims 2-4,
The simulation includes a step of calculating an air volume and power consumption from a frequency of electric power input to a fan of the cooling tower, and calculating a cooling water feed temperature from an outside air condition, the air volume, a cooling water flow rate, and a cooling water return temperature. Cooling system characterized by a simulation. In the cooling system in any one of Claims 1-5,
Furthermore, a gas-liquid separator that separates the heat medium derived from the solar heat collector into liquid and gas, supplies the gas as driving energy to the absorption chiller, and returns the liquid to the solar heat collector, The said control apparatus calculates the amount of solar heat collection based on the temperature and pressure of the gas isolate | separated by the said gas-liquid separator, and the temperature of the liquid which returns from the said absorption refrigeration machine, The cooling system characterized by the above-mentioned. In the cooling system in any one of Claims 1-5,
The cooling system further comprises a pyranometer for measuring the amount of solar radiation, and the control device calculates a solar heat collection amount based on the measured amount of solar radiation and time.

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