JP2008215678A - Operation control method of air-conditioning system and air conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method of an air conditioning system and the like capable of improving energy consumption efficiency, in particular, in partial load. <P>SOLUTION: In this operation control method of the air conditioning system where a load-side unit 200 and a heat source-side unit 100 having a compressor 101 operated with compressor operational frequency, a heat source-side heat exchanger 104 performing heat exchange, and a heat source-side fan 108 operated with fan motor operational frequency, are connected by piping, a process for changing the fan motor operational frequency of the heat source-side fan 108, a process for judging the total power consumption of power consumption of the compressor 101 in accompany with the change, and power consumption of the heat source-side fan 108, and a process for deciding whether the change of fan motor operational frequency is further performed or not on the basis of the total power consumption, are performed until it is judged that predetermined conditions are satisfied. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an air conditioning system that performs cooling and heating by circulating a refrigerant. In particular, it is intended to improve energy consumption efficiency by controlling the heat source side fan.

  Conventionally, COP (Coefficient of Performance) has been used to represent the performance related to energy consumption of an air-conditioning system capable of performing an air conditioning operation. This COP expresses the amount of power consumption with respect to the heating capacity or cooling capacity (the amount of heat per hour supplied to the load unit side, hereinafter referred to as the capacity) as a numerical value. Capacity and power consumption when the air conditioning load in the side unit (indoor unit) (the amount of heat required by the load side unit, hereinafter referred to as load) is 100% (hereinafter referred to as 100% load) By quantity.

  For example, in a general office, a load of about 50% of a 100% load (hereinafter referred to as a partial load, including a load of about 50%) occurs when viewed throughout the year. In recent years it has been found that the rate of doing this is high. Therefore, rather than evaluating the performance with 100% load COP, it is better to evaluate by COP throughout the year including about 50% load (this is called APF (Annual Performance Factor)). Since the evaluation can be made more in line with actual use, the trend of using APF has become prominent and is used as a standard for energy saving (see, for example, Patent Document 1).

In order to improve this APF, for example, energy consumption efficiency (performance) in heating and cooling (intermediate heating, intermediate cooling) operation corresponding to the case of partial load, such as a time when the climate is relatively mild such as spring and autumn. ) To reduce power consumption, and if this can be accommodated, it is possible to truly increase efficiency and save energy throughout the year.
Japanese Patent Laid-Open No. 9-79650 (FIG. 1)

  Here, for example, consider the breakdown of power consumption in each device. The compressor is dominant (about 90%) in power consumption at 100% load. On the other hand, in the partial load, the ratio of the compressor is large (about 80%), but heat exchange between the air and the refrigerant is efficiently performed in the heat exchanger (heat source side heat exchanger) of the heat source side unit (outdoor unit). The percentage of fans (heat source side fans) to perform is high (about 20%).

  This fan on the heat source side operates the fan (fan motor) to set the condensation temperature and evaporation temperature in the heat source side heat exchanger to the target condensation temperature and evaporation temperature (hereinafter referred to as the target condensation temperature and target evaporation temperature). (Rotate) and send air to exchange heat. Here, the target condensing temperature and the target evaporating temperature, which are references for heat source side fan control, may be changed based on, for example, the outdoor air temperature (the temperature of the air that exchanges heat with the refrigerant), but basically, Regardless of the magnitude of the load, the target condensation temperature and target evaporation temperature that optimize the COP at 100% load are set.

  Therefore, in an operation at a partial load (hereinafter referred to as an intermediate operation), it cannot always be said that the optimum target condensation temperature and target evaporation temperature are reached, and the heat source side fan, for example, rotates at full speed corresponding to 100% load ( Control at the maximum operating frequency).

  Thus, in the intermediate operation, since the heat source side fan is not controlled to perform efficient operation, there is room to improve the control of the heat source side fan in order to improve the energy consumption efficiency in the intermediate operation. Conceivable. On the other hand, improvements by hardware such as using an inverter circuit for controlling the number of revolutions, such as DC brushless of the fan motor that constitutes the heat source side fan, has reached a limit, and a dramatic improvement cannot be expected.

  Accordingly, the present invention provides a control method for an air conditioning system that can improve the energy consumption efficiency particularly in a partial load by controlling the system and the like in consideration of power consumption not only in the compressor but also in the heat source side fan. The purpose is to obtain.

  An operation control method for an air conditioning system according to the present invention includes a load-side unit having a load-side heat exchanger and an expansion valve, a compressor that performs a refrigerant compression operation, and a heat source that performs heat exchange between air and the refrigerant. Operation of a side heat exchanger and an air conditioning system that operates at a fan motor operating frequency and has a heat source side unit having a heat source side fan that sends air to the heat source side heat exchanger, and performs cooling and heating by circulating a refrigerant In the control method, the step of changing the fan motor operating frequency of the heat source side fan, the step of determining the power consumption of the compressor and the heat source side fan accompanying the change, and further calculating the total power consumption, and the total consumption The process of determining whether to further change the fan motor operating frequency based on the power is performed until it is determined that the predetermined condition is satisfied.

  According to the present invention, the fan motor operating frequency for the heat source side fan is changed, and the power consumption of each of the compressor and the heat source side fan is determined. For example, the total power consumption is the minimum, a predetermined value or less. This is done until it is determined that the specified condition is satisfied, so that the fan motor operating frequency can be reduced and the power consumption can be reduced while maintaining the capacity based on the load size. Can be improved.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating an air conditioning system according to Embodiment 1 of the present invention. The air conditioning system of FIG. 1 includes a heat source side unit (outdoor unit) 100 and a load side unit (indoor unit) 200, which are connected by a refrigerant pipe to constitute a main refrigerant circuit to circulate the refrigerant. ing. Among the refrigerant pipes, a pipe through which a gaseous refrigerant (gas refrigerant) flows is referred to as a gas pipe 300, and a pipe through which a liquid refrigerant (liquid refrigerant, which may be a gas-liquid two-phase refrigerant) flows is referred to as a liquid pipe 400. Further, although not particularly limited refrigerant circulated, for example, an HFC-based refrigerant, R410A, R404A also, CO _2, may be used and ammonia.

  In the present embodiment, the heat source side unit 100 includes a compressor 101, an oil separator 102, a four-way valve 103, a heat source side heat exchanger 104, a capillary 105, an accumulator (gas-liquid separator) 106, a heat source side fan 108, and a heat source. A side expansion device (expansion valve) 109, an inter-refrigerant heat exchanger 110, and a bypass expansion device 111 are included.

  The compressor 101 compresses the sucked refrigerant, and sends out (discharges) an arbitrary pressure based on the operating frequency. The compressor 101 of the present embodiment has a variable capacity inverter compressor having an inverter circuit that can finely change the capacity (the amount of refrigerant sent out per unit time) by arbitrarily changing the operating frequency, for example. And The operation of the compressor 101 is performed based on the compressor operating frequency Fcomp determined by the compressor operating frequency control unit 132A described later so that the capacity supply for the load magnitude in the load side unit 200 can be maintained. The oil separator 102 separates the lubricating oil discharged from the compressor 101 together with the refrigerant. The separated lubricating oil is returned to the compressor 101 with the flow rate controlled by the capillary 105.

  The four-way valve 103 switches the refrigerant flow between the cooling operation and the heating operation based on an instruction from the heat source side control device 131. The heat source side heat exchanger 104 performs heat exchange between the refrigerant and air (outdoor air). For example, during the heating operation, it functions as an evaporator, and performs heat exchange between the low-pressure refrigerant that has flowed in through the heat source side expansion device 109 and the air to evaporate and evaporate the refrigerant. Further, during the cooling operation, it functions as a condenser and performs heat exchange between the refrigerant compressed in the compressor 101 flowing in from the four-way valve 103 side and air, thereby condensing and liquefying the refrigerant. The heat source side heat exchanger 104 is provided with a heat source side fan 108 in order to efficiently exchange heat between the refrigerant and the air. The heat source side fan 108 has an inverter circuit, and can control the fan motor operating frequency arbitrarily to change the fan rotational speed finely. Thereby, for example, in the heat source side heat exchanger 104, the amount of heat taken from the refrigerant during the cooling operation or the amount of heat taken by the refrigerant during the heating operation can be changed. The operation of the heat source side fan 108 is performed based on a fan motor operation frequency Ffan determined by a fan motor operation frequency control unit 132C described later.

  The inter-refrigerant heat exchanger 110 exchanges heat between the refrigerant flowing through the main flow path of the refrigerant circuit and the refrigerant branched from the flow path and adjusted in flow rate by the bypass expansion device 111 (expansion valve). . In particular, when it is necessary to supercool the refrigerant during the cooling operation, the refrigerant is supercooled and supplied to the load side unit 200. The liquid flowing through the bypass throttle device 111 is returned to the accumulator 106 via the bypass pipe 107. The accumulator 106 is means for storing, for example, liquid excess refrigerant.

  Further, in the heat source side unit 100, a discharge pressure sensor 121 is provided in a discharge side pipe of the compressor 101 and detects a high pressure (hereinafter referred to as discharge pressure) Pd due to refrigerant discharge of the compressor 101. It is provided as a detecting means for detecting. In addition, a suction pressure sensor 123 that is provided in a pipe on the suction side of the compressor 101 and detects a low pressure (hereinafter referred to as suction pressure) Ps due to refrigerant suction is also provided as a detection unit. The discharge pressure Pd approximates the condensing pressure during the cooling operation, the suction pressure Ps approximates the evaporation pressure during the heating operation, and further the saturation temperature Tc, Te that can be derived from the discharge pressure Pd, the suction pressure Ps, the condensing temperature, The evaporation temperature can be determined. Further, in the present embodiment, the heat source side air temperature sensor 122 is provided as a detection means for detecting the temperature, and the outside air sucked into the heat source side unit 100 by the operation (rotation) of the heat source side fan 108 is detected. The temperature of the air (the temperature of the air that exchanges heat with the refrigerant, hereinafter referred to as the outside air temperature) is detected. Based on the signals transmitted from these detection means, the heat source side control device 131 determines physical quantities such as temperature and pressure, performs arithmetic processing, etc., and performs heat processing on the heat source side including the compressor 101 and the heat source side fan 108. The device (means) of the unit 100 is controlled.

  In the present embodiment, the heat source side control device 131 includes a heat source side processing unit 132 made of, for example, a microcomputer, and a heat source side storage unit 133. The heat source side processing means 132 is connected to, for example, a load side control device (not shown) provided in the load side unit 200 via a communication line (not shown) or the like, and performs various detections in the system. Control of the entire system is performed based on a signal related to the detection of the means (sensor). In the present embodiment, in particular, each device (means) of the heat source side unit 100 is controlled to perform processing for reducing power consumption in the heat source side unit 100. Therefore, it is assumed that each unit includes a compressor operation frequency control unit 132A, a compressor power consumption determination unit 132B, a fan motor operation frequency control unit 132C, a fan motor power consumption determination unit 132D, and a target temperature setting unit 132E.

  The compressor operating frequency control unit 132A determines the compressor operating frequency Fcomp so that the capacity corresponding to the magnitude of the load in the load side unit 200 can be supplied, and supplies the compressor 101 with the compressor operating frequency Fcomp. The process which transmits the signal which instruct | indicates driving | operation is performed. Further, the compressor power consumption determination unit 132B determines the power consumption of the compressor 101 (compressor power consumption Wcomp) based on the compressor power consumption data stored in the heat source side storage unit 133.

  The fan motor operation frequency control unit 132C performs a process of transmitting a signal instructing operation at the fan motor operation frequency Ffan to the heat source side fan 108. In particular, in the present embodiment, based on the instruction from the target temperature setting unit 132E, the fan motor operating frequency Ffan increased or decreased by the frequency change width ΔFfan is transmitted as a new fan motor operating frequency Ffan, and the heat source side The fan 108 is operated. The fan motor power consumption determining unit 132D determines the power consumption (fan power consumption Wfan) of the heat source side fan 108 based on the fan motor power consumption data stored in the heat source side storage unit 133.

  The target temperature setting unit 132E sets a target condensation temperature (during cooling operation) and a target evaporation temperature (during heating operation) in the heat source side heat exchanger 104. Therefore, based on the total power consumption Wtotal of the power consumption determined by the compressor power consumption determination unit 132B and the fan motor power consumption determination unit 132D, it is determined whether or not to perform processing for further finding a condition that can reduce power consumption. Then, the target condensing temperature or the target evaporating temperature is set based on the determination, and an instruction to change the fan motor operating frequency Ffan is given to the fan motor operating frequency control unit 132C.

  The heat source side storage unit 133 temporarily or long-term stores data that is referred to when each unit of the heat source side processing unit 132 performs processing, data obtained by arithmetic processing of each unit, and the like. In particular, in the case of the present embodiment, as will be described later, the compressor power consumption data representing the relationship between the parameters of the compressor 101 and the power consumption, and the fan representing the relationship between the parameters of the heat source side fan 108 and the power consumption. Motor power consumption data is stored as data configured in a table (matrix) format. Further, the initial value of the target condensation temperature (initial target condensation temperature) using the outside air temperature as a parameter, the initial value of the target evaporation temperature (initial target evaporation temperature), and the total consumption of the compressor 101 and the heat source side fan 108 at each temperature. The power Wtotal0 is stored as data (hereinafter referred to as target data) configured in a table format. Moreover, the program in which the process sequence which each part of the heat-source side process means 132 performs was shown is memorize | stored.

  Here, by storing compressor power consumption data, fan motor power consumption data, and the like in the heat source side storage means 133, the data content can be easily changed, and the form of the air conditioning system (of the compressor 101) The power consumption can be determined in accordance with the type, the number of load side units 200, the installation environment of the heat source side unit 100, and the like. These may be expressed as mathematical formulas, and the power consumption may be determined by the compressor power consumption determination unit 132B and the fan motor power consumption determination unit 132D calculating.

  On the other hand, the load side unit 200 includes a load side heat exchanger 201, a load side expansion device (expansion valve) 202, and a load side fan 203. The load side heat exchanger 201 performs heat exchange between the refrigerant and air. For example, it functions as a condenser during heating operation, performs heat exchange between the refrigerant flowing in from the gas pipe 300 and air, condenses and liquefies the refrigerant (or gas-liquid two-phase), and moves to the liquid pipe 400 side. Spill. On the other hand, during the cooling operation, it functions as an evaporator, performs heat exchange between the refrigerant and the air whose pressure is reduced by the load-side throttle device 202, causes the refrigerant to take heat of the air, evaporates it, and vaporizes it. It flows out to the piping 300 side. In addition, the load side unit 200 is provided with a load side fan 203 for adjusting the flow of air for heat exchange. The operating speed of the load-side fan 203 is determined by, for example, user settings. The load side expansion device 202 is provided to adjust the pressure of the refrigerant in the load side heat exchanger 201 by changing the opening degree.

  FIG. 2 is a diagram showing power consumption in the heat source side unit 100 in the case of a partial load. For example, in the case of a cooling / heating operation at a 100% load, the target condensation temperature during the cooling operation in the heat source side heat exchanger 104 is set to be low in order to supercool the refrigerant. On the other hand, the target evaporation temperature during the heating operation is set to be high in order to overheat the refrigerant. In order to achieve the temperature set in this way, the heat source side fan 108 is operated.

  On the other hand, in the case of an intermediate operation corresponding to a partial load, even if the target condensing temperature corresponding to 100% load and the target evaporating temperature are not set as severe as the target temperature, the capacity required by the load side unit 200 can be supplied. it can. Therefore, for example, even if the condensation temperature has increased (evaporation temperature has decreased), as shown in FIG. 2, the fan operating capacity of the heat source side fan 108 (which depends on the fan motor operating frequency Ffan) is kept low to some extent. However, it is possible to improve the energy consumption efficiency by suppressing the power consumption to a low level, leading to an improvement in the APF (where the power consumption of the discharger 101 is increased if the fan operating capacity is excessively reduced, Become).

  Therefore, the system of the present embodiment changes the fan motor operating frequency Ffan for the heat source side fan 108 while maintaining the capacity supply to the load so as to reduce the total power consumption Wtotal of the compressor 101 and the heat source side fan 108. Each device (means) of the heat source side unit 100 is controlled.

  Therefore, the compressor 101 and the heat source are set so that the condensation temperature and evaporation temperature of the heat source side heat exchanger 104 become, for example, the initial target condensation temperature and the initial target evaporation temperature at 100% load, which are determined corresponding to the outside air temperature, for example After controlling the side fan 108 and the like, the fan motor operating frequency Ffan for the heat source side fan 108 is decreased. Along with the change, the compressor operating frequency Fcomp and the discharge pressure Pd of the compressor 101 also change and the compressor power consumption Wcomp also changes in order to supply the capacity corresponding to the load. In this way, the total power consumption Wtotal of the compressor 101 and the heat source side fan 108 when the conditions in the heat source side fan 108 are changed is within the minimum (more precisely, the fan motor operating frequency Ffan is changed). The range between the widths may be the lowest, but here, it is assumed that it is the lowest in the judgment of the target temperature setting unit 131E) until the condition is found, the fan motor operating frequency Ffan of the heat source side fan 108 is changed. To go. Thereby, power consumption can be reduced and energy consumption efficiency can be improved.

  Here, the above processing is performed by changing the magnitude of the load, the outside air temperature, etc. At this time, instead of increasing or decreasing the fan motor operating frequency Ffan at that time, the initial target condensing temperature, The fan motor operating frequency Ffan is decreased after controlling to the initial target evaporation temperature. Thereby, it is only necessary to perform control to decrease without increasing the operating frequency, and since it can be stabilized immediately, it can be quickly found by simple processing.

  FIG. 3 is a diagram illustrating the relationship between the parameters representing the characteristics of the compressor 101 and the heat source side fan 108 and the respective power consumption. In the compressor 101, parameters that affect the compressor power consumption Wcomp are related to the compressor operating frequency Fcomp, the discharge pressure Pd (the refrigerant saturation temperature Tc based on the discharge pressure), the suction pressure Ps, and the suction temperature Ts. It can be said. These parameters vary depending on the load size in the load side unit 200. Therefore, the compressor power consumption data represents the relationship between the load size in the load side unit 200 and the compressor power consumption Wcomp.

  FIG. 3A shows the relationship between the discharge pressure and the suction pressure when the compressor operating frequency Fcomp is constant. The compressor power consumption Wcomp varies with the discharge pressure rather than the suction pressure. I understand that FIG. 3B shows the relationship between the operating capacity of the compressor 101 and the suction temperature when the discharge pressure and the suction pressure are constant. The compressor power consumption Wcomp is calculated from the suction temperature. As can be seen from FIG. Here, since the operating capacity depends on the compressor operating frequency, the compressor power consumption Wcomp changes to the compressor operating frequency rather than the intake temperature. From the above, in this embodiment, the compressor power consumption determination unit 132B determines the compressor power consumption Wcomp based on the compressor power consumption data based on the compressor operating frequency Fcomp and the discharge pressure Pd. . However, a pressure sensor and a temperature sensor may be provided on the suction (low pressure) side of the compressor 101, and the suction pressure Ps and the suction temperature Ts may be detected to determine the compressor power consumption Wcomp.

  On the other hand, as shown in FIG. 3C, it can be seen that the power consumption Wfan of the heat source side fan 108 changes depending on the fan motor operating frequency Ffan. Therefore, in the present embodiment, fan motor power consumption determination unit 132D determines fan power consumption Wfan based on fan motor power consumption data based on fan motor operating frequency Ffan.

  Next, the operation of the air conditioning system will be described. First, basic refrigerant circulation in the main refrigerant circuit during cooling operation will be described. The high-temperature, high-pressure gas (gas) refrigerant pressurized and discharged by the compressor 101 is condensed by passing through the heat source side heat exchanger 104 from the four-way valve 103 and becomes a liquid refrigerant. leak. The refrigerant flowing into the load-side unit 200 through the liquid pipe 400 is converted into a low-temperature and low-pressure liquid refrigerant whose pressure is adjusted by adjusting the opening degree of the load-side expansion device 202 in each load-side unit 200. Evaporates and flows out. Then, the gas flows into the heat source side unit 100 through the gas pipe 300, is sucked into the compressor 101 through the four-way valve 103 and the accumulator 106, and is circulated by being pressurized and discharged.

  Further, basic refrigerant circulation in the main refrigerant circuit during heating operation will be described. The high-temperature, high-pressure gas (gas) refrigerant pressurized and discharged by the compressor 101 flows from the four-way valve 103 through the gas pipe 300 into each load-side unit 200. In each load-side unit 200, the pressure is adjusted by adjusting the opening degree of the load-side expansion device 202, condensing by passing through the load-side heat exchanger 201, and in an intermediate-pressure liquid or gas-liquid two-phase state It becomes a refrigerant and flows out of the load side unit 200. The refrigerant flowing into the heat source side unit 100 through the liquid pipe 400 is pressure-adjusted by adjusting the opening degree of the heat source side expansion device 109, evaporates by passing through the heat source side heat exchanger 104, and becomes a gas refrigerant. Then, the refrigerant is sucked into the compressor 101 through the four-way valve 103 and the accumulator 106, and circulated by being pressurized and discharged as described above.

  FIG. 4 is a diagram illustrating a flowchart of processing in the heat source side control unit 132 included in the heat source side control device 131. Based on FIG. 4, the control of the apparatus (means) in the present embodiment performed by the heat source side control means 132 when the above-described refrigerant circulation is performed will be described. Here, processing during cooling operation will be described. Therefore, the heat source side heat exchanger 104 operates as a condenser.

  In the heat source side control means 132, the target temperature setting unit 132E determines whether or not the target temperature changing condition is satisfied (ST1). Here, the target temperature changing condition is, for example, based on a signal from the heat source side air temperature sensor 122 in which the set temperature is changed in the load side unit 200 and the magnitude of the load changes beyond a predetermined reference. The outside air temperature judged in the above has changed beyond a predetermined standard.

  When it is determined that the target temperature changing condition is satisfied, the target temperature setting unit 132E searches the target data stored in the heat source side storage unit 133, and sets the initial target condensing temperature Tcm0 corresponding to the determined outside air temperature ( ST2).

  The fan motor operation frequency control unit 132C performs control so that the heat source side fan 108 is operated at full speed, for example, so that the initial target condensation temperature Tcm0 is obtained. On the other hand, the compressor operating frequency control unit 132 </ b> A also determines the compressor operating frequency Fcomp so as to supply the capacity corresponding to the magnitude of the load of the load side unit 200, and operates the compressor 101.

  Based on the signal from the discharge pressure sensor 121, the discharge pressure Pd is determined. Then, the saturation temperature (condensation temperature) Tc on the discharge side of the compressor 101 is determined based on the discharge pressure Pd, reaches the initial target condensing temperature Tcm0, and determines that the cooling operation is stable (ST3). The unit 132E gives an instruction. Receiving the instruction, the fan motor operating frequency control unit 132C operates at a fan motor operating frequency Ffan that is reduced by a predetermined frequency change width ΔFfan from the current fan motor operating frequency Ffan (Ffan = current Ffan−ΔFfan). ), A signal is transmitted to the heat source side fan 108 (ST4).

  FIG. 5 is a diagram conceptually illustrating examples of compressor power consumption data and fan motor power consumption data. FIG. 5A shows compressor power consumption data. Since the compressor power consumption Wcomp depends on the saturation temperature Tc that can be derived from the discharge pressure Pd and the compressor operating frequency Fcomp, it is configured in a table format based on these parameters. FIG. 5B shows fan motor power consumption data. Fan motor power consumption data is also configured in a table format. Since the fan motor power consumption Wfan depends on the fan motor operating frequency Ffan, the fan motor operating frequency Ffan and the fan motor power consumption Wfan are stored in association with each other.

  The compressor power consumption determination unit 132B searches the compressor power consumption data (FIG. 5A) stored in the heat source side storage unit 133, and discharge pressure Pd of the compressor 101 at the fan motor operating frequency Ffan. The compressor power consumption Wcomp corresponding to the saturation temperature (condensation temperature) Tc and the compressor operating frequency Fcomp is determined. The fan motor power consumption determining unit 132D also searches the fan motor power consumption data (FIG. 5B) stored in the heat source side storage unit 133, and determines the fan motor power consumption Wfan corresponding to the operating frequency Ffan (ST5). ).

  The target temperature setting unit 132E calculates the total Wtotal of the fan motor power consumption Wfan and the compressor power consumption Wcomp. Then, it is compared with the previous total Wtotal * to determine whether or not Wtotal is smaller than Wtotal * (ST6). Here, since the previous total Wtotal * does not exist at the beginning, the determination is made based on the data of the total power consumption Wtotal0 with respect to the initial target condensing temperature Tcm0 stored as target data in the heat source side storage unit 133.

  If Wtotal is smaller than Wtotal *, the saturation temperature Tc corresponding to the current discharge pressure Pd is replaced with the target condensation temperature Tcm (ST7). On the other hand, if Wtotal is not smaller than Wtotal * (if Wtotal is equal to or greater than Wtotal *), target condensation temperature Tcm is maintained as it is (set to saturation temperature Tc corresponding to previous discharge pressure Pd) (ST8). Then, the target temperature setting unit 132E instructs the fan motor operation frequency control unit 132C to operate at the fan motor operation frequency Ffan that is increased by the frequency change width ΔFfan from the current fan motor operation frequency Ffan (Ffan = current Ffan + ΔFfan). ), A signal is transmitted to the heat source side fan 108 (ST9). Although not described in detail, the same processing is performed for setting the target evaporation temperature during heating operation and determining the fan motor operating frequency Ffan at that time.

  As described above, according to the system of the first embodiment, the heat source side control unit 132 of the heat source side control device 131 reduces the fan motor operating frequency Ffan for the heat source side fan 108 within a range where the capacity supply to the load can be maintained. Since the control is performed by finding the lowest point of the total power consumption Wtotal of the compressor 101 and the heat source side fan 108, the fan motor operating frequency Ffan is reduced based on the load size to reduce the power consumption. The energy consumption efficiency can be improved. Also, in order to find a low power consumption, the fan motor operating frequency Ffan is decreased after controlling the initial target condensing temperature and the initial target evaporating temperature once, so it is determined quickly by simple processing. be able to. Further, the compressor power consumption Wcomp is determined based on the compressor operating frequency Fcomp and the saturation temperature Tc based on the discharge pressure Pd, and the fan motor power consumption Wfan is determined based on the fan motor operating frequency Ffan. In the determination of the compressor power consumption Wcomp, it is possible to make a highly accurate determination even with a small number of parameters by making a determination based on the parameter that most affects the power consumption. Then, by storing these in advance in the heat source side storage means 133 as compressor power consumption data and fan motor power consumption data, it is possible to easily change the data.

Embodiment 2. FIG.
In the above-described embodiment, the saturation temperatures (condensation temperature and evaporation temperature of the heat source side heat exchanger 104) Tc and Te are derived based on the discharge pressure Pd and the suction pressure Ps. Sensors provided elsewhere, such as data relating to the magnitude of the load set in the load-side unit 200, which obtains condensation temperature data, etc., by providing a temperature sensor in the middle part of the pipe through which the refrigerant passes in the exchanger 104 If the power consumption of the compressor 101 can be estimated and determined based on the data based on the detection, setting, etc., the power consumption may be determined based on such data. As a result, the range of judgment can be expanded, and it can be expected that detailed power consumption judgment is performed at a lower cost.

Embodiment 3 FIG.
In the above-described embodiment, the heat source side control means 132 performs processing until it is found on the condition that the total power consumption Wtotal is found to be the lowest. However, the present invention is not particularly limited to this condition. For example, when the frequency change width ΔFfan is short and it takes time to find it, a predetermined value is set, and when the total power consumption Wtotal is equal to or lower than the predetermined value, the process is terminated. However, the fan motor operating frequency, target condensing temperature, and target evaporating temperature with low total power consumption can be obtained in a short time.

  Further, for example, a predetermined time may be set. For example, on the condition that the heat source side control means 132 cannot find a place where the total power consumption Wtotal is minimum in a predetermined time, if it is determined that the condition is satisfied, the total consumption is not the minimum. The fan motor operating frequency, the target condensing temperature, the target evaporating temperature, etc. are determined in advance by determining the fan motor operating frequency, etc., at which the electric power Wtotal is low, or by finding out in the above-described process of changing the fan motor operating frequency You may make it obtain.

  In the above-described embodiment, the present invention is applied to the air conditioning system, but the present invention can also be applied to other systems that constitute a refrigerant circuit using a refrigeration cycle such as a refrigeration system.

It is a figure showing the air conditioning system which concerns on Embodiment 1 of this invention. It is a figure showing the power consumption in the heat-source side unit 100 in the case of partial load. It is a figure showing the relationship between the compressor 101, the heat-source side fan 108, and power consumption. It is a figure showing the flowchart of the process in the heat-source side control means. It is a figure showing compressor power consumption data and fan motor power consumption data.

Explanation of symbols

  100 heat source side unit, 101 compressor, 102 oil separator, 103 four-way valve, 104 heat source side heat exchanger, 105 capillary tube, 106 accumulator, 107 bypass pipe, 108 heat source side fan, 109 heat source side expansion device, 110 heat between refrigerants Exchanger, 111 Bypass throttle device, 121 Discharge pressure sensor, 122 Heat source side air temperature sensor, 131 Heat source side control device, 132 Heat source side processing means, 132A Compressor operating frequency control unit, 132B Compressor power consumption judgment unit, 132C Fan Motor operation frequency control unit, 132D fan motor power consumption determination unit, 132E target temperature setting unit, 133 heat source side storage means, 200 load side unit, 201 load side heat exchanger, 202 load side expansion device, 300 gas piping, 400 liquid Piping.

Claims (10)

A load-side unit having a load-side heat exchanger and an expansion valve;
Compressor that performs refrigerant compression operation, heat source side heat exchanger that performs heat exchange between air and the refrigerant, and heat source side fan that operates at a fan motor operating frequency and sends the air to the heat source side heat exchanger In an operation control method of an air conditioning system in which a heat source side unit having a pipe is connected, and the refrigerant is circulated to perform air conditioning.
Changing the fan motor operating frequency of the heat source side fan;
Determining the power consumption of the compressor and the power consumption of the heat source side fan accompanying the change, and further calculating the total power consumption;
And a step of determining whether to further change the fan motor operating frequency based on the total power consumption, until it is determined that a predetermined condition is satisfied, and an operation control method for an air conditioning system, .   The fan motor operating frequency of the heat source side fan and the compression operating frequency of the compressor are set with the condensation temperature or evaporation temperature of the refrigerant in the heat source side heat exchanger when it is determined that the predetermined condition is satisfied as a target temperature. The method for controlling the operation of the air conditioning system according to claim 1, wherein: A load-side unit having a load-side heat exchanger and an expansion valve, a compressor that operates at a predetermined compressor operating frequency, a heat-source-side heat exchanger that performs heat exchange between air and refrigerant, and a fan motor operating frequency An air conditioning system for connecting a pipe with a heat source side unit having a heat source side fan that sends the air to the heat source side heat exchanger and circulating the refrigerant,
The heat source side unit is:
A fan motor operating frequency control unit that changes a fan motor operating frequency of the heat source side fan, and a change in the fan motor operating frequency by the fan motor operating frequency control unit according to the power consumption after the fan motor operating frequency is changed An air conditioning system comprising: a heat source side control unit having a determination unit that determines whether or not to perform further. The heat source side control means includes
Determining a compressor operating frequency for supplying a capacity based on a load size in the load side unit, and comprising a compressor operating frequency controller for operating the compressor;
The determination part of the heat source side control means is
A compressor power consumption determination unit that determines power consumption of the compressor when the fan motor operating frequency is changed;
A fan motor power consumption determining unit that determines power consumption of the heat source side fan when the fan motor operating frequency is changed,
The total power consumption determined by the compressor power consumption determination unit and the fan motor power consumption determination unit is calculated, and the fan motor operation frequency control unit changes the fan motor operation frequency based on the total power consumption. The air conditioning system according to claim 3, wherein the determination as to whether or not to perform further is performed until it is determined that the predetermined condition is satisfied.   The fan motor operating frequency control unit uses the fan motor operating frequency control unit as the target temperature, which is the condensation temperature or evaporation temperature of the refrigerant in the heat source side heat exchanger when the determining unit determines that the predetermined condition is satisfied. The air conditioning system according to claim 4, wherein the compressor operating frequency control unit determines the compressor operating frequency.   6. The determination unit according to claim 4, wherein the determination unit determines whether to further change the fan motor operation frequency, based on the predetermined condition that the total power consumption is minimum. Air conditioning system.   5. The determination unit determines whether to further change the fan motor operation frequency, based on the predetermined condition that the total power consumption is equal to or less than a predetermined value. Or the air conditioning system of 5.   The fan motor operating frequency control unit changes the fan motor operating frequency so that the fan motor operating frequency is maximized in an initial state, the heat source side fan is operated, and the fan motor operating frequency is decreased. The air conditioning system according to any one of claims 3 to 7. A heat source that stores compressor power consumption data that uses data of power consumption in predetermined parameters of the compressor and fan motor power consumption data that uses data of power consumption in predetermined parameters of the heat source side fan Side storage means,
9. The compressor power consumption determination unit and / or the fan motor power consumption determination unit determine power consumption based on compressor power consumption data and fan motor power consumption data, respectively. The air conditioning system according to any one of the above.   The refrigerant saturation temperature based on the compressor operating frequency and the discharge pressure of the compressor is set as a predetermined parameter of the compressor, and the fan motor operating frequency is set as a predetermined parameter of the heat source side fan. Item 10. The air conditioning system according to Item 9.

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