JP4905939B2 - Operation control method for air conditioning system - Google Patents

Description

  The present invention relates to an operation control method for an air conditioning system, and more particularly to an operation control method for an air conditioning system capable of improving energy saving in an air conditioning zone having a plurality of air conditioners and improving the durability and reliability of each air conditioner.

  A plurality of air conditioners with superior coefficient of performance (COP) or air conditioners with different cooling methods (for example, water cooling type and air cooling type) may be mixed and installed in one room (air conditioning zone). Even when only air conditioners of the same model (model) are installed, the operating efficiency may vary greatly depending on the degree of performance deterioration due to aging or the like, or the difference in outdoor unit installation conditions. In such a case, if the operating rate of the air conditioner with low operating efficiency is high and the operating rate of the air conditioner with high operating efficiency continues to be low, the air conditioning zone as a whole contradicts the demand for energy saving.

  Furthermore, the air conditioners currently on the market have made significant progress in terms of operating efficiency at high output close to the rated output, but the partial load characteristics are not so much considered. Therefore, in a place where a distributed air conditioning system is adopted, operating the air conditioner in a high-efficiency output range, that is, a high output range is the key to improving energy saving.

Regarding a technique for controlling a plurality of air conditioners, a technique for reducing the overall peak power consumption by a plurality of systems obtained by dividing a multi air conditioner into a plurality of groups is disclosed (for example, see Patent Document 1). Moreover, the technique which controls so that the operating time of each compressor becomes equal about the air conditioner provided with the several compressor is disclosed (for example, refer patent document 2). However, none of these technologies relates to an operation control technology for an air conditioning zone in which a plurality of air conditioners having different performance, type, outdoor unit installation conditions, and the like are mixedly installed.
JP 2006-29694 A JP-A-5-10607

  The present invention is for solving such a problem, and in an air conditioning zone having a plurality of air conditioners, an operation control technology of an air conditioning system capable of improving energy saving and improving reliability of each air conditioner. It is to provide.

The gist of the present invention is as follows. That is,
(1) An air conditioning system operation control method in an air conditioning zone having a plurality of air conditioners, which compares the operating efficiency of each air conditioner, sets in advance priority air conditioners to be preferentially operated, and other than priority air conditioners When one air conditioner reaches the operation start temperature condition, it instructs the non-operating priority air conditioner to start operation without instructing the one air conditioner to start operation, or The priority air conditioner is instructed to increase its output (priority operation control), and then the priority operation control is canceled when the one air conditioner reaches the shutdown temperature condition. And

  The present invention gives priority to the air conditioner having the highest operating efficiency (cooling efficiency) at the time when a plurality of air conditioners having different models (models) and years elapsed after installation are installed in the same air conditioning zone. By operating it, it is possible to improve the energy saving performance of the entire air conditioning zone.

(2) In this case, use the operating efficiency of the air conditioner calculated based on the COP characteristic curve considering the degree of deterioration of the outdoor unit heat exchange performance and the temperature condition of the outdoor unit installation location for each air conditioner. Can do.

  In general, a COP characteristic curve (with respect to a change in outdoor unit ambient temperature (suction temperature)) under an indoor rated condition (for example, maintained at a room temperature of 25 ° C.) is expressed as shown in FIG. 7 using an outdoor unit heat exchange capacity coefficient (R) as a parameter. . Here, the heat exchange capacity coefficient R is expressed by the following equation.

R = KA (t) / KA (0) (1)
In the equation (1), KA (0) is a KA value when new, and KA (t) is a KA value after a lapse of time t from the new time. Thus, (1-R) represents the degree of deterioration of the heat exchanger after the elapse of time t from the new article. The KA value can be obtained as follows. That is, with reference to FIG. 8 (Molière diagram), the heat exchange amount (heat radiation amount) Qc in the condenser is
Qc = Gr (h3-h1 ′) (2)
It becomes. Here, the refrigerant circulation amount Gr can be obtained, for example, by measuring the compressor frequency. h1 ′ is the refrigerant enthalpy in a state of being supercooled from the condensation temperature Tc corresponding to the refrigerant high pressure Pc. The supercooling temperature can be obtained from the refrigerant circulation amount and the expansion valve opening, but an average supercooling temperature (3 to 5 ° C.) may be used approximately. From these,
KA = Qc / MTD (3)
It becomes. Here, MTD is a logarithm average temperature difference and is represented by MTD = (Δ1−Δ2) / log (Δ1 / Δ2). Note that Δ1 = T1-Tc and Δ2 = T2-Tc.

  Furthermore, from these relationships, the “operation efficiency” of each air conditioner can be obtained by the following steps with reference to FIG. First, the KA value of the corresponding air conditioner is calculated according to equation (3) (step S401). Further, the capability coefficient R is obtained from the equation (1) (step 402). Next, a COP characteristic curve (R = R (t)) considering the aging of the air conditioner is specified from the obtained R value (step S403) (see FIG. 7). Further, a COP value C (t) at a point corresponding to the outdoor unit ambient temperature (To) on the specific COP characteristic curve is obtained. This value is the operating efficiency of the air conditioner (step S404). The calculation in the above step is performed for each air conditioner, and the one with the highest COP value is selected as the priority air conditioner (step S405). The priority air conditioner thus selected is instructed to increase the operation instruction or output to operate (step S406).

(3) In the above, the setting of the priority air conditioner can be updated every predetermined time or every time an air conditioner other than the priority air conditioner reaches the operation start temperature condition.
Deterioration of outdoor unit heat exchangers progresses day by day, and the temperature conditions of the outdoor unit installation location change momentarily depending on solar radiation conditions, the operating conditions of surrounding outdoor units, etc., so priority air conditioners are set at regular intervals. Thus, the priority air conditioner can be selected based on the latest information, and the energy saving effect can be further improved.

(4) In this case, the priority operation control can be instructed only when the load factor of the air conditioner is not high in each air conditioning zone and there is no large deviation in the load sharing of each air conditioner.

If priority operation control is performed when the air conditioning load of the entire air conditioning zone is excessive, there is a risk that the target air conditioning effect cannot be obtained. In the present invention, in order to avoid such a risk, priority operation control is not performed when the air conditioning load is excessive. This determination is made based on the current operating rate of the air conditioner group. For example, when it is defined as “high load state” at 50% or more of the compressor operating rate, the operating state of each compressor is A1: 0%, A2: 20%, A3: 70%, A4: 100%. In some cases, it can be determined that the load is high.
Furthermore, when the load in the air conditioning zone is unevenly distributed, it is assumed that local high temperatures cannot be suppressed even if the total amount of sensible heat of the air conditioner is sufficient for the air conditioning load of the entire air conditioning zone. Can be done. In order to avoid such a risk, the presence or absence of load imbalance in the air conditioning zone is evaluated by calculating a variance value of the operating rate of the compressor. For example, when the dispersion value of the compressor operation rate (= (actual load / rated output) × 100 (%)) is set to “load uneven distribution state” of 2000 or more, the operation state of each compressor is A1: 0. %, A2: 5%, A3: 10%, A4: 95%, A5: 100%, the average value of the operating rate is 42%. Although not determined, the variance value is 2066, and it can be determined that the load is unevenly distributed.
Judgment of excessive air conditioning load or load sharing bias is not limited to that based on the operating rate of the compressor or the like. For example, it is also possible to make a determination based on measured temperatures inside, around, and the like of each air conditioner.

(5) Further, when the operation start temperature condition of the one air conditioner continues even after a predetermined time has elapsed from the start of the priority operation control, the operation start or operation continuation instruction is also given to the one air conditioner. can do.
When it is determined that the load cannot be handled by the operation of only the priority air conditioner, it is possible to easily cope with the high air conditioning load by setting both air conditioners to the operating state.

(6) Furthermore, when the operation start or operation continuation instruction is continuously generated for a predetermined number of times or continues for a predetermined time or more, the air conditioner is excluded from the priority air conditioner and the priority operation control is canceled. Can do.
Accordingly, when it is determined that the operation of the priority air conditioner cannot cope with the operation, the priority operation control can be canceled.

(7) Further, when the air conditioner that is not the priority air conditioner and the prioritized air conditioner are operating in parallel, and the priority air conditioner is in the condition for canceling the operation, appropriately select the air conditioner that should be instructed to cancel the operation. Therefore, the priority air conditioner can be selected again and a stop instruction can be given to an air conditioner with a lower priority.
As described above, the priority air conditioner is selected based on the COP calculation value using the air conditioner model, the outdoor unit deterioration degree, and the outdoor unit suction temperature as parameters. On the other hand, because the outdoor unit suction temperature dynamically changes depending on the solar radiation conditions and the airflow conditions at the outdoor unit installation location (for example, the temperature environment deteriorates because the nearby outdoor unit started operation), the operation started. Sometimes an air conditioner that satisfies the conditions to be a priority air conditioner does not satisfy the conditions as a priority air conditioner when the operation is canceled. In the present invention, in order to eliminate the continuation of priority operation control by an inappropriate priority air conditioner, the priority air conditioner is re-selected in response to the relaxation of the air conditioning load.

(8) Furthermore, even when one air conditioner does not reach the operation start condition, when the temperature at a specific position in the air conditioning zone exceeds a predetermined value, one or more than the priority air conditioner An operation start instruction can be given to the air conditioner.

In the case of machine room air conditioning or the like, the object can be air-conditioned (cooled) particularly when there are devices or the like having severe temperature conditions.
(9) Furthermore, when the cumulative operation time of any one of the air conditioners or the predetermined components of the air conditioner exceeds a predetermined value, the priority air conditioner is excluded from the priority air conditioner targets, and a new priority air conditioner is added. You can set the machine.

  When only a specific air conditioner is always selected as a priority air conditioner, the deterioration of the air conditioner becomes more significant as compared to other air conditioners. According to the present invention, the service life of each air conditioner can be averaged. Here, examples of the “predetermined component” whose service life should be averaged include a fan of an indoor / outdoor unit in which wear deterioration progresses depending on an operation time, a compressor, and the like.

(10) Furthermore, when the air conditioners to be excluded from the priority air conditioners exceed a predetermined ratio with respect to the total number of air conditioners installed in the air conditioner zone, the priority operation control can be canceled. .
If air conditioners that can be selected as priority air conditioners are limited, not only will it not be possible to sufficiently achieve the energy savings that are the benefits of the original priority air conditioners, but it may be possible to deteriorate energy efficiency on the contrary. This is for limiting the priority operation control under such a situation.

(11) Furthermore, a plurality of priority air conditioners with priorities set are set, and when priority operation control is started, operation instructions are given sequentially from the higher priority air conditioners, and when priority operation control is canceled, priority orders are set. Can be instructed to stop operation sequentially from the subordinate air conditioners.

  By setting a plurality of priority air conditioners, it is possible to avoid the risk of not being able to cope with the air conditioning load and to improve both durability and reliability.

  According to each of the above-described inventions, the air conditioner having a high operating efficiency is actively operated as a load of the entire room, and the air conditioner is loaded in a state close to the rated capacity, or the air conditioner is inefficient. By making the operation command to the machine passive, it is possible to improve the energy saving performance as the air conditioner group.

  Hereinafter, each embodiment of the air-water cooling operation control method of an air conditioner according to the present invention will be described in more detail with reference to FIGS. Needless to say, the scope of the present invention is described in the claims and is not limited to the following embodiments.

(First embodiment)
FIG. 1 is a diagram showing an air conditioning system 1 according to an embodiment of the present invention. FIG. 2 is a diagram showing a flow of selecting a priority air conditioner. FIG. 3 is a diagram showing a transition flow from the normal operation control to the priority operation control of the air conditioner A1. FIG. 4 is a diagram showing a release flow from the priority operation control of the priority air conditioner A4. FIG. 5 is a diagram showing the concept of priority air conditioner selection. FIG. 10 is a block diagram showing details of the air conditioning control unit 3a of the control computer 3. As shown in FIG.

Referring to FIG. 1, an air conditioning system 1 includes four air conditioners A1 to A4 in a room (zone) 2 to be air conditioned. Temperature sensors S1 to S4 are connected to the indoor unit side of each air conditioner, and temperature sensors S5 to S8 are connected to the outdoor unit side, and the respective measured temperatures T1 to T4 and T5 to T8 are measured. It is comprised so that it may transmit to the computer 3 for control which manages operation control.
Further, referring to FIG. 10, the air conditioning control unit 3 a of the control computer 3 includes a CPU, a ROM, a RAM, and the like (not shown) and has each function shown in the figure. In the figure, part A is a database. The operation efficiency table 21, the priority air conditioner table 23, the COP characteristic curve table 25, the load state table 27, the load sharing status table 29, and the operation instruction number table 31 are stored using the database as storage means. The upper limit operation time table 33 is stored. Here, the database is illustrated as an example, but it is sufficient if numerical data is systematically stored and can be read out.
Further, B section is a calculation section that performs calculation processing, and is provided with efficiency deviation calculation means 51, outdoor unit deterioration degree calculation means 53, operation efficiency calculation means 55, load factor calculation means 57, and air conditioning load distribution value calculation means 59. ing.
Further, there is a C section as another function such as operation instruction and measurement data acquisition, and an operation instruction means 81, a measured temperature acquisition means 83, an elapsed time measurement means 85, and an accumulated operation time acquisition means 87 are provided.

Table 1 shows the specifications (model, performance, installation conditions) of each air conditioner. The database of the control computer 3 stores a COP characteristic curve table 25 for the models X and Y using the same capability coefficient R as that of FIG.

  Next, the priority air conditioner selection flow will be described with reference to FIG. First, assuming that i = 1, the capacity coefficient R1 of the air conditioner A1 is obtained by the above-described equations (1) to (3) (steps S101 and S102). Next, the COP characteristic curve of the air conditioner A1 is specified based on the COP characteristic table of the model X and the capacity coefficient R1 of the air conditioner A1 (step S103). Further, the COP value of the point corresponding to the outdoor unit ambient temperature T5 of the specified COP characteristic curve is obtained (step S104). This value is the operating efficiency C1 of the air conditioner A1. This operation is also performed for other air conditioners (steps S105 and S106). The result is shown in FIG. When the operating efficiencies C1 to C4 of all the air conditioners are determined, the priority air conditioner is next selected (step S107). As shown in FIG. 7, here, A4 having the highest COP value is selected as the priority air conditioner.

(Transition flow to priority operation control)
Next, with reference to FIG. 3, the transition flow from the normal operation control to the priority operation control will be described using the air conditioner A1 as an example. It is assumed that the air conditioner A1 is in an operation stopped state in the initial state (step S201), and the temperature of the temperature sensor S1 is equal to or higher than the priority operation control start temperature TH (step S202). Next, it is determined whether or not the air conditioner A is a priority air conditioner (step S203). If applicable, the air conditioner A is selected as the priority air conditioner, and an operation start instruction is issued to the air conditioner A (step S209). If not, it is next determined whether or not a priority air conditioner exists in the same air conditioning zone (step S204). When a priority air conditioner exists, that air conditioner is the target of this control. Here, air conditioner A4 corresponds to this (step S205).

  Next, it is determined whether or not the load status of the zone is normal (step S206). This step is for not performing priority operation when the load of the entire room is large or when the load is concentrated at a specific location, and it is determined based on the current operating rate of the air conditioner group and the load dispersion value. . When it is determined that the zone is in a high load state or the load is largely biased, priority operation control is not performed and normal operation control is performed (step S209). If it is determined not to be in a high load state, it is next determined whether or not the priority air conditioner A4 is operating at a rated capacity or higher (step S207). When it corresponds, it determines with the capacity | capacitance of air conditioner A4 having no margin, and an operation start instruction | indication is given to air conditioner A1 (step S209). If it is less than the rated capacity, an instruction to start operation or an instruction to increase the output is given to the air conditioner A4 (step S208). Thus, the transition flow to priority operation control ends.

(Priority operation control release flow)
Next, with reference to FIG. 4, the cancellation | release flow from the state which priority air conditioner A4 is performing rated operation according to the above-mentioned transition flow is demonstrated. The rated operation air conditioner A1 transfers the operation to the priority air conditioner A4 and is in an operation standby state (step S301). In the initial state, j = 0 is set (step S302). Here, j is a number added when the indoor temperature rise continues only by the operation of the priority air conditioner, and the risk of not being able to maintain the indoor set temperature or the risk of priority operation concentrating on a specific air conditioner is avoided. (Details will be described later). Further, a timer reset (τ = 0) for the control interval is performed (step S303).

  After a predetermined time (τ1) has elapsed due to the priority operation control (step S304), it is determined whether or not the temperature T1 of the temperature sensor S1 has decreased from the operation start temperature TH (step S305). If applicable, it is further determined whether or not the temperature is equal to or lower than the operation cancellation temperature TL (step S306). When T1 ≦ TL, the priority operation control of the air conditioner A4 is canceled (step S314), and the air conditioner A1 returns to the normal temperature control. When TH> T1> TL (NO in step S306), operation is performed in that state until the next control interval.

  When T1> TH, an operation start instruction is issued to the air conditioner A1 (step S307). According to the operation instruction, the air conditioner A1 and the air conditioner A4 are operated in parallel, and this parallel operation state is continued until TH> T1. When TH> T1 is satisfied after the parallel operation, it is determined which operation of the air conditioner A1 or the air conditioner A4 should be canceled. First, the risk avoidance count is added (j = j + 1) (step S308). Next, it is determined whether or not the risk avoidance count j has exceeded a predetermined threshold M (step S309). When the value is equal to or less than the threshold value M, the priority air conditioner is reselected (step S310), and it is further determined whether or not the air conditioner A4 is still the priority air conditioner (step S311). If the air conditioner A4 has not reached the priority air conditioner, the priority operation control is canceled and normal temperature control is performed (step S314). When the air conditioner A4 is selected again as the priority air conditioner in step S311, an operation stop instruction is issued to the air conditioner A4 (step S312), and the above steps are repeated.

  When the threshold value M is exceeded in step S309, the air conditioner A4 is excluded from the priority air conditioners in relation to the air conditioner A1 (step S313). Furthermore, priority operation control is canceled and normal temperature control is performed (step S314).

In the present embodiment, priority operation control related to the air conditioner A1 is exemplified, but the same priority operation control is independently performed for the air conditioners A2 to A4.
Moreover, although the example which controls four air conditioners as an example was shown in this embodiment, the number of units is not limited to this.
Furthermore, although the priority air conditioner is only the air conditioner A4, it may be controlled by setting a plurality of air conditioners as priority air conditioners and assigning priorities to them. In this case, air conditioners having COP values within a certain range may be handled as the same group.

(Second embodiment)
FIG. 1 is a diagram showing an air conditioning system 20 according to another embodiment of the present invention. The difference between the present embodiment and the air conditioning system 1 according to the first embodiment is that in the air conditioning system 1, the temperature sensors S <b> 1 to S <b> 4 are arranged in the vicinity of each air conditioner, whereas in the air conditioning system 20, The temperature sensor S9 representing the air conditioner is disposed in the vicinity of the indoor cooling load (for example, communication equipment) 22. Since other configurations are the same as those in the first embodiment, the description thereof is omitted.

  As for the control, in the first embodiment, the control of FIGS. 2 and 3 is performed based on the temperatures T1 to T4 of the corresponding sensor, whereas in the present embodiment, the control is performed based on the representative temperature T9 in the temperature sensor S9. , 3 is performed. Thereby, the failure risk avoidance capability by the temperature rise of communication apparatuses can be improved more.

  The present invention can be widely applied to an air conditioning system using a compression air conditioner regardless of a heat source type, a refrigerant type, an air conditioning system, or the like.

It is a figure showing air-conditioning system 1 concerning a first embodiment. It is a figure which shows the selection flow of a priority air conditioner. It is a figure which shows the transition flow from normal operation control of air conditioner A1 to priority operation control. It is a figure which shows the cancellation | release flow from priority operation control of priority air conditioner A4. It is a figure which shows the concept of priority air-conditioner selection. It is a figure which shows the air conditioning system 20 which concerns on 2nd embodiment. It is a figure which shows the COP characteristic curve which used the capability coefficient R as a parameter. It is a figure which shows the principle which calculates | requires KA value on a Mollier diagram (ph diagram). It is a figure which shows the step which calculates | requires the operating efficiency of an air conditioner. It is a block block diagram which shows the detail of the air-conditioning control part 3a of the computer 3 for control.

Explanation of symbols

1, 20 ... Air conditioning system ... Same zone (indoor)
3 .... Control computer 22 .... Cooling load (communication equipment)
A1 to A4 ... Air conditioners S1 to S9 ... Temperature sensors

Claims (6)

An air conditioning system operation control method in an air conditioning zone having a plurality of air conditioners,
Comparing the operating efficiency of each air conditioner, pre-setting priority air conditioners to be preferentially operated;
When one air conditioner other than the priority air conditioner reaches the operation start temperature condition, it instructs the non-operating priority air conditioner to start operation without instructing the one air conditioner to start operation, or , A step of instructing the priority air conditioner in operation to operate with increased output (hereinafter referred to as priority operation control),
Thereafter, when the one air conditioner reaches an operation stop temperature condition, a step of canceling the priority operation control ,
The operating efficiency is the operating efficiency of the air conditioner determined based on the COP characteristic curve considering the outdoor unit heat exchange performance deterioration degree (1-R) for each air conditioner and the temperature condition of the outdoor unit installation location. is there,
An operation control method for an air conditioning system.
However, R (heat exchange capacity coefficient) is expressed by the following equation.
R = KA (t) / KA (0) (1)
Here, KA (0): KA value when new, KA (t): KA value after elapse of time t from new.   The setting of the priority air conditioner is updated every predetermined time or whenever an air conditioner other than the priority air conditioner reaches an operation start temperature condition. Operation control method. The priority operation is performed only when the load factor average value of each air conditioner does not exceed a predetermined upper limit value and there is no bias in the load sharing evaluated by the variance value of the compressor operation rate of each air conditioner. The operation control method for an air conditioning system according to claim 1 or 2 , wherein control is performed. Including a step of instructing the one air conditioner to start operation or continue operation when the operation start temperature condition of the one air conditioner continues even after a predetermined time has elapsed since the start of priority operation control. The operation control method for an air conditioning system according to any one of claims 1 to 3 . In claim 4 , when the operation start or operation continuation instruction for the one air conditioner is continuously generated a predetermined number of times or continues for a predetermined time or more, the air conditioner is excluded from the priority air conditioner, or the one An air conditioning system operation control method comprising the steps of excluding the air conditioner from the priority operation control target and releasing the priority operation control. 5. The method according to claim 4 , further comprising a step of selecting a priority air conditioner again and instructing a low priority air conditioner to stop when the one air conditioner is in an operation cancellation condition. Operation control method for air conditioning system.

Images