JP5394047B2 - Method and apparatus for measuring cooling capacity of air conditioning system by package type air conditioner - Google Patents

Description

The present invention relates to a cooling capacity during operation in an individual air conditioning system (hereinafter also referred to as “PAC system”) using a package type air conditioner (hereinafter also referred to as “PAC”) such as a building multi. The present invention relates to a simple measurement method. More specifically, the current performance (capacity and efficiency) of individual air conditioning systems and PACs can be easily grasped, especially for capacity controllers such as inverters, among PACs. The present invention relates to a method and an apparatus for estimating cooling capacity.

  A package type air conditioner composed of an indoor unit and an outdoor unit is installed in an air conditioning load such as a building and connected by a refrigerant pipe. In addition, it is necessary to check the maintenance of performance for maintenance management after delivery. There is JIS B 8615-1 as a method for measuring the capability of such a PAC. However, the measurement method according to JIS is a measurement method that should be performed by installing a PAC in an environmental test room. The PAC installed in a general building with disturbance cannot be measured accurately. Is not applicable.

The capability of the PAC is selected by selecting the result of the measurement according to JIS described in the catalog as the rated capability. However, the confirmation of the performance maintenance after the delivery is necessary in the following cases, for example.
(1) When there is a change in the load compared to the estimated amount after completion of the building, such as a sudden change in weather conditions such as an increase in midsummer days, the number of visitors if the building is a store, or a deviation in production performance from the plan if the building is a factory .
(2) When the usage of the building changes, such as partition changes, room allocation, or redesign. Also, the concept of commissioning has been attracting attention recently, but if the owner or the facility operator can confirm that the expected performance has been achieved for the load at the time of delivery, the burden of responsibility will be clarified.
If it is possible to verify and evaluate whether or not a PAC having an appropriate capacity with respect to the load is installed, it is possible to appropriately take improvement measures such as adding a PAC, changing a model, or changing an operation method. In order to relatively confirm the performance after the PAC system is operated after the PAC is installed, it is conceivable to grasp the load state of the air-conditioned room by the measured value of the thermometer or hygrometer. It is necessary to measure and labor is required.

In general, to measure the capacity of an air conditioner or cooler (the amount of heat of cooling / heating),
(A) A method of obtaining from the temperature, enthalpy and flow rate of the refrigerant,
(B) Method of obtaining from air temperature, enthalpy and flow rate,
(C) There is a method in which the above (A) and (B) are combined.
Among these, the method of obtaining from the refrigerant side of (A) is highly accurate, but it is very difficult to measure the flow rate of the refrigerant especially during operation in the field where the PAC system is installed. This is because in order to measure the state of the refrigerant, it is necessary to stop the PAC system once and insert a meter into the pipe.
On the other hand, in the method of obtaining from the air side of (B), it is difficult to obtain the amount of heat with high accuracy due to the formation of the temperature distribution. For unit coolers for refrigerated warehouses, attempts have been made to accurately measure the capacity from the air side blown out from the PAC (Patent Document 1), but work such as attachment / detachment of measurement ducts with sensors is required. Therefore, it is difficult to apply to an individual air conditioning system using a large number of PACs.

Japanese Patent No. 3608655

As described above, there is currently no simple and effective method for measuring the capacity during the operation in the field where the individual air conditioning system by PAC is installed.
The present invention has been made in view of the above points, and measures the capacity of the PAC system, particularly the cooling capacity, during operation with high accuracy without stopping the operation of the PAC system and without requiring large-scale equipment. The purpose is to do.

The present invention which intends to solve such problems is a package type in which an outdoor unit having a capacity-controlled compressor and an outdoor heat exchanger and an indoor unit having an indoor heat exchanger are connected by a refrigerant pipe. A method for measuring the cooling capacity of an air conditioning system using an air conditioner,
First, in the present invention, the liquid supply pipe through which the refrigerant is sent from the outdoor unit to the indoor unit is heated or cooled, and the cooling capacity is set based on the data on the change in the power consumption, the condensing pressure and the evaporation pressure of the compressor accordingly. Estimated .

  A capacity-controlled compressor, for example, a compressor with an inverter, changes its rotational speed in accordance with the air conditioning load. The present invention forcibly applies a load to the PAC system, grasps the tendency of changes in the operation of the compressor, and estimates the capacity corresponding to the load at that time. For example, the compression pressure can be obtained by measuring the condensation pressure and the evaporation pressure, and the efficiency of the compressor can be calculated from this and used. As a forced load, it is practical to “heat” because it is applied as a simulated load to the liquid refrigerant during cooling, but even if the liquid refrigerant is “cooled”, it is possible to grasp changes in the operating state of the compressor. Therefore, the present invention can be applied. In the present invention, the cooling capacity is estimated by grasping the tendency of such a change and based on it.

In obtaining the change data, the heating amount after heating or cooling the liquid feeding tube or the enthalpy difference for the cooling amount is used, and at least after the liquid feeding tube is heated or cooled from the enthalpy difference in the evaporator. The multiplication coefficient α _(i) is defined from the enthalpy difference excluding the enthalpy difference for the heating amount or the cooling amount, and its function form is determined . According to this, it is possible to estimate the performance of the PAC arithmetically without requiring a large facility. The estimation result is easy to explain because it is an application of the Mollier diagram.
From this point of view, the present invention provides a packaged air conditioner in which an outdoor unit having a capacity-controlled compressor and an outdoor heat exchanger and an indoor unit having an indoor heat exchanger are connected by a refrigerant pipe. A method for measuring the cooling capacity of the air conditioning system used,
Heating or cooling the liquid supply pipe through which refrigerant is sent from the outdoor unit to the indoor unit, and estimating the cooling capacity from the following formula based on the data of changes in power consumption, condensation pressure and evaporation pressure of the compressor accordingly Like
From the enthalpy difference Δh _(i) excluding the enthalpy difference for the heating amount or the cooling amount after heating or cooling the liquid feeding pipe from the enthalpy difference in the evaporator , the multiplication factor α _(i) is expressed as Δh _(i) = is defined as _{α (i) · Δh (0} ),
The cooling capacity Q ₍₀₎ is estimated by the following equation, and is a method for measuring the cooling capacity of an air conditioning system using a packaged air conditioner.
Cooling capacity Q ₍₀₎ = Qin _(i) / {1- [alpha] _(i). (W _(i) / W ₍₀₎ ). ([Eta] _(i) / [eta] ₍₀₎ ). ([Delta] hc ₍₀₎ / Δhc _(i) )}
Qin _(i) is the amount of heat added to the liquid feeding tube, (W _(i) / W ₍₀₎ ) is the rate of change in power consumption when the amount of heat Qin _(i) is added to the liquid feeding tube , (η _(I) / η ₍₀₎ ) is the rate of change in the efficiency of the compressor when heat quantity Qin _(i) is added to the liquid feed pipe, and (Δhc ₍₀₎ / Δhc _(i) ) is the liquid feed pipe It is the ratio of the compressor theoretical enthalpy difference when the amount of heat Qin _(i) is added.

In the present invention according to another aspect, the following calculation is performed in the order of one of procedure 1A and procedure 1B → the other procedure 1A and the remaining procedure 1B → procedure 3 → procedure 4 . In such a case, a normal personal computer can be applied.
Procedure 1A: Enthalpy difference Δh _(i) obtained by subtracting the enthalpy difference for the heating amount or the cooling amount after heating or cooling the liquid feeding pipe from the enthalpy difference in the evaporator, using the multiplication factor α _(i) It is defined as
Δh _(i) = α _(i) · Δh ₍₀₎
Δh ₍₀₎ is the enthalpy difference in the evaporator of the indoor unit during normal operation. Procedure 1B: From the general characteristics of the refrigeration cycle, the multiplication factor α _(i) is the change rate PH ₍₀₎ of the pressure of the high-pressure gas. / PH _(i) and the index β are defined as follows:
α _(i) = (PH ₍₀₎ / PH _(i) ) ^β
Where PH is the condensation pressure.
Step 3: Cooling capacity Q ₍₀₎ , power W _(0), and compressor efficiency η ₍₀₎ representing the operating state of the air conditioning system when the amount of cooling heat is not added to the liquid feeding pipe using the formula of step 1A And compressor theory enthalpy difference Δhc ₍₀₎ ,
Cooling capacity Q _(i) , power W _(i) , compressor efficiency η _(i) and compressor theory representing the operating state of the air conditioning system when heating amount or cooling amount Qin _(i) is added to the liquid feed pipe Enthalpy difference Δhc _(i)
And the following formula is obtained under the condition of Q ₍₀₎ = Q _(i) .
Q ₍₀₎ = Qin _(i) / {1- [alpha] _(i). (W _(i) / W ₍₀₎ ). ([Eta] _(i) / [eta] ₍₀₎ ). ([Delta] hc ₍₀₎ / [Delta] hc _{( i)} )}
Procedure 4: The following equation is obtained from the equation of procedure 1B and the general function form (= a · (PH / PL) ^b ) of the compressor efficiency η _(i) .
Q ₍₀₎ = Qin _(i) / {1- (PH ₍₀₎ / PH _(i) ). ^Beta. (W _(i) / W ₍₀₎ ). (Χ _(i) / χ ₍₀₎ ) ^b (Δhc ₍₀₎ / Δhc _(i) )}
a and b are specific coefficients determined by the compressor, PH is a condensation pressure, PL is an evaporation pressure, and χ is a compression ratio (PH / PL). It is.

Either procedure 1A or procedure 1B may be performed first. According to the present invention, since it is only necessary to perform a certain calculation on the measurement value, it can be used universally regardless of the scale and application of the PAC system.
The above-described procedures 1 to 4 are estimation formulas for the cooling capacity Q ₍₀₎ .
Q ₍₀₎ = Qin _(i ) / {1- (PH ₍₀₎ / PH _(i) ). ^Beta. (W ₍₀₎ / W _(i) ). (Χ ₍₀₎ / χ _(i) ) ^b (Δhc ₍₀₎ / Δhc _(i) )}
Here, i = 1 to n (n is 3 or more)
It is a procedure for obtaining.
In the present invention according to another aspect, the measured values of power W ₍₀₎ and W _(i) , condensation pressure PH ₍₀₎ and PH _(i) , evaporation pressure PL ₍₀₎ and PL _(i) , ₍₀₎ , W _(i) , PH ₍₀₎ , PH _(i) , PL ₍₀₎ , PL _(i) obtained from χ ₍₀₎ , χ _(i) , Δhc ₍₀₎ , Δhc _(i) Is substituted into the above estimation equation to solve the simultaneous equations to estimate the cooling capacity Q (0).
Therefore, for example, when being programmed and used on a personal computer or the like, the following are programmed and recorded on a hard disk or an appropriate storage medium of the personal computer.
(1) Input method of measured power W ₍₀₎ and W _(i) , condensation pressure PH ₍₀₎ and PH _(i) , evaporation pressure PL ₍₀₎ and PL _(i) ,
(2) W ₍₀₎ , W _(i) , PH ₍₀₎ , PH _(i) , PL ₍₀₎ , PL _(i) input in (1) to χ ₍₀₎ , χ _(i) , Δhc ₍₀₎ , Δhc _(i) refrigerant physical property data and calculation formula for calculating,
(3) W ₍₀₎ , W _(i) , PH ₍₀₎ , PH _(i) input in (1) and χ ₍₀₎ , χ _(i) , Δhc ₍₀₎ calculated in (2 ₎ , Δhc _(i) is substituted into the above estimation equation,
(4) Solution for obtaining the most probable values of β and b satisfying the simultaneous equations of i = 1 to n in the above estimation formula (for example, least square method)

Furthermore, power consumption of the compressor, condensation pressure measured with a power meter provided on the power line that supplies power to the compressor, a pressure gauge provided on the refrigerant discharge pipe of the compressor, and a pressure gauge provided on the refrigerant suction pipe of the compressor The relationship between at least the amount of heating or cooling Qin _(i) with respect to the liquid feeding pipe and β and b may be obtained using each value of the evaporation pressure.

According to the present invention, since a measurement value can be obtained from a sensor included in a normal PAC system, it is not necessary to change the setting value of the PAC in estimating the cooling capacity. In other words, it does not affect equipment owners / operators. Q ₍₀₎ , β and b are three or more heating or cooling amounts added to the liquid supply pipe Qin _(i) , ie compression with {Qin ₍₁₎ , Qin ₍₂₎ , Qin ₍₃₎ } Using the measured values of the machine power consumption W _(i) , condensing pressure PH _(i) , evaporation pressure PL _(i) , and calculated values of χ _(i) , Δhc _(i) Find to satisfy the equation. For example, there is an iterative calculation using a least square method.
Further, the present invention uses an outdoor unit having a capacity-controlled compressor and an outdoor heat exchanger, and a packaged air conditioner in which an indoor unit having an indoor heat exchanger is connected by a refrigerant pipe. A package type air conditioner that heats or cools a liquid supply pipe through which a refrigerant is sent from an air conditioner to an indoor unit, and estimates cooling capacity based on data of changes in power consumption, condensation pressure, and evaporation pressure of the compressor accordingly The measuring device for carrying out the cooling capacity measuring method of the air conditioning system by the machine can be mounted on the pipe wall of the liquid feeding pipe and is covered with a heat insulating material for applying cold heat or heat to the liquid feeding pipe And a heat source device separate from the tube, the heat source device comprising: a thermostatic bath filled with liquid; a pump for supplying the liquid liquid from the thermostatic bath to the tube; and the thermostatic bath To heat or cool the liquid It is characterized by having a exchanger.

  According to the present invention, it is possible to measure the cooling capacity of the PAC system with high accuracy without stopping the operation of the PAC system and without requiring a large facility.

  FIG. 1 shows an example in which the present invention is applied to a building multi-use in which a plurality of indoor units are connected to one outdoor unit. In this figure, air conditioning rooms R1 and R2 in which two indoor units 1b are installed in one room are shown, and the refrigerant pipe to another air conditioning room is extended thereafter. The PAC system 1 mainly includes an outdoor unit 1a, a plurality of indoor units 1b, a refrigerant pipe outgoing pipe 1c connecting them, and a refrigerant pipe return pipe 1d. The outdoor unit 1a includes a compressor, an outdoor heat exchanger, and other accumulators (all not shown). The exhaust heat of the outdoor heat exchanger varies depending on the system, and in the case of an air cooling system, a blower 1e is provided in the apparatus, and in the case of a water cooling system such as a so-called water mulch, a cooling tower (not shown). Is connected to the outdoor unit 1a through the cooling water pipe. The indoor unit 1b has a built-in indoor heat exchanger 1f, and the blower 1g supplies conditioned air to an air conditioning load such as a room. A decompression device such as an expansion valve 1h is provided on the refrigerant pipe outgoing pipe (hereinafter referred to as “liquid feeding pipe”) 1c on the indoor unit 1b side. The liquid refrigerant is vaporized by the heat exchanger 1f in the indoor unit 1b by the decompression device, thereby cooling the air-conditioned rooms R1 and R2.

  In the present embodiment, a heat source device that heats or cools the liquid feeding pipe 1c with a predetermined amount of heat is used. 1 shown in FIG. 1 is an example of a heat source device, and a thermostat 2a filled with a test liquid such as water, a pump 2b, a flow meter 2c for measuring the amount of liquid supplied to the liquid feeding pipe 1c, It is mainly composed of a thermometer 2d that measures the temperature at which the liquid is sent to the liquid pipe 1c and the return temperature, and a heat pump 2e that applies hot or cold heat to the thermostat 2a. The thermostat 2a is filled with a liquid fluid 2f such as water or brine, and can be sent out by a pump 2b. The heat pump 2e includes a heat exchanger 2g that heats or cools the test solution in the thermostat 2a and a heat exchanger 2h that releases or collects heat into the atmosphere, and the former is immersed in the thermostat 2a. The liquid fluid in the tank 2a is heated or cooled.

  Furthermore, in this embodiment, the tube 3 covered with the heat insulating material 3a is used so as to apply cold heat or heat to the tube wall of the liquid feeding tube 1c by the liquid fluid in the thermostatic chamber 2a. The tube 3 is a hollow tube through which the liquid fluid can circulate, and has a flexible structure that can be wound around the liquid supply tube 1c as shown in the drawing, leaving a portion in contact with the liquid supply tube 1c, and a sheet-like heat insulation It is covered with a material 3a. Although the tube 3 may be integrated with the heat source device 2, it may be separated and connected via a one-touch joint or the like at a site where the air conditioning system is operated.

  The heat source device 2 measures data for calculating the amount of heat heated and cooled as described above. That is, the amount of heat is calculated by multiplying the difference between the liquid feeding temperature and the return liquid temperature obtained by the thermometer 2d by the measurement value of the flow meter 2c. The tube 3 gives warm heat or cold heat from the outside to the liquid refrigerant flowing through the liquid feeding pipe 1c. Here, although an example of heating will be given, the amount of heating is sufficiently small with respect to the cooling capacity, so the liquid refrigerant will not be gasified. If these functions are limited to heating, an electric heater can be substituted more easily, and the applied heat can be measured with an ammeter. Depending on the form of the heat source device, the heat generating means may directly cool or heat the liquid feeding pipe 1c, and in that case, separate from the heat quantity measuring means.

  In addition, the outdoor unit 1a is provided with pressure gauges PH and PL for measuring the pressures of the high-pressure side refrigerant and the low-pressure side refrigerant of the compressor, respectively, similarly to a normal outdoor unit. An indoor thermometer TR is provided on the indoor unit side of the PAC system, that is, the air conditioning rooms R1 and R2, and the room temperature is measured. In addition, a temperature sensor Tout for measuring the outside air temperature is provided at a suitable outdoor location. Note that the indoor thermometer TR and the temperature sensor Tout are provided in a normal PAC system, and are used to measure the timing at which the estimation method according to the present invention is performed, and are not used for the calculation of estimation.

A method for measuring the cooling capacity of the PAC system having the above configuration will be described below. The packaged air conditioner having a capacity control mechanism such as an inverter is operated with a cooling capacity Q ₍₀₎ corresponding to the air conditioning load. This Q ₍₀₎ is unchanged unless the air conditioning load changes.

(1) Procedure for Estimating Cooling Capacity First, the tube 3 connected to the heat source device 2 is assembled at an appropriate position of the liquid feed pipe 1c, in this case, the place before the liquid feed pipe 1c branches, that is, the main pipe portion M. The estimation of the capacity of the PAC during operation avoids the time when the fluctuation of the outside air load is large such as in the morning or evening, and selects the implementation time in the time zone where the fluctuation of the outside air temperature _Tout is small, for example, from 10:00 to 14 hours. During the performance estimation, we measured two systems with different outdoor units, such as two floors on the intermediate floor and the east and west sides of one floor, and one of them was operated by adding cold heat to the liquid supply pipe. Then, the cooling capacity is estimated, and the other performs normal operation. That is, the power consumption amount, the condensing pressure, and the evaporating pressure of the compressor are measured for the liquid feeding pipe of another outdoor unit as described above. Since outdoor units are generally located close to living rooms for the same purpose and outdoor or air-conditioned floors, it is easy to compare the measured values with the system on the side where the load is applied. is there.
When the outside air temperature _Tout does not change and the power of the PAC on the normal operation side does not change, it is determined that the air conditioning load has not changed. Then, the pressure gauges of the compressor discharge pipe and the compressor suction pipe around the pressure gauge in the outdoor unit are opened, and the display device is connected. The power consumption can also be visually observed from existing boards. If the PAC on the normal driving side changes suddenly or gradually but greatly, the measurement of the PAC on the loaded side is stopped.

FIG. 2 shows a procedure of a system for performing capacity estimation. The following procedure can be performed using a computer, and the calculation results can be obtained by displaying or printing on a personal computer screen. However, the cooling capacity can be estimated from the calculation results described later by using a comparison table in the personal computer. You may memorize | store and contrast, and a maintenance worker may judge by visual observation. As an example, the signals of the pressure gauges PH and PL and the wattmeter W provided on the high-pressure side and the low-pressure side of the compressor can be transmitted to a portable personal computer for comparison and calculation described later. At this time, if the measured values of the outside air temperature and the room temperature can also be captured and displayed on the personal computer, the work can be interrupted as the air temperature fluctuates.
First, it is confirmed that the load fluctuations of the system that performs the cooling capacity estimation and the other system other than the system do not affect the accuracy of the capacity estimation. That is, to measure the outside air temperature _{T out} and room temperature _{T R} (step S1), the time rate of change of the outside air temperature _{T out (δT out} / _δt) with time rate of change of the room temperature _{T R (δT R} / _δt) is predetermined After confirming that it is below the threshold (step S2), measure the condensation pressure (high pressure) PH ₍₀₎ , evaporation pressure (low pressure) PL ₍₀₎ , and power (power consumption) W ₍₀₎ of the operating PAC. (Step S3).
Next, using the heat source device 2, as shown in FIG. 3, three kinds (i = 1 to 3) of heat quantity Qin _(i) are heated or cooled in the liquid feeding pipe 1c step by step (step S4). For example, with respect to the liquid refrigerant at 50 ° C. that has exited the compressor (not shown) of the outdoor unit 1a, cold heat of 20 ° C. (i = 1), 17 ° C. (i = 2), 14 ° C. (i = 3) Is granted. The three ways of applying heat are to solve three unknown numerical values of the ability estimation formula described later using simultaneous equations.

After the cycle state of the PAC was changed by heating or cooling the heat _{Qin (i)} is stabilized, condensation pressure _PH of each heat _{Qin (i) (i),} for measuring the evaporation pressure _{PL (i),} the power _{W (i)} (Step S5). Finally, to confirm that time rate of change of the outside air temperature T _out (δT / δt) with time rate of change of the room temperature T _R (δT / δt) is below a threshold (step S6), and later on the basis of the measured data A capability estimation formula is derived (step S7). The derivation of the capacity estimation formula (step S7) is first performed as shown in FIG. 3 in which the condensation pressure PH _(i) and the evaporation pressure PL for each of the heat quantity Qin _(i) in three ways (i = 1 to 3) in the capacity estimation formula. _(I) Substituting power W _(i) and making it simultaneous.
Next, a convergence calculation is performed by using three unknown numerical values of the ability estimation formula described later as parameters to obtain simultaneous solutions. As a result, the cooling capacity Q ₍₀₎ of the PAC, which is one of the three numerical values that are the obtained solutions, can be estimated. The above threshold depends on the required estimation accuracy.
That is, in the present invention, the “threshold value” needs to be set smaller as the higher estimation accuracy is required. The cooling load (cooling capacity Q ₍₀₎ ) is unchanged during the time when power, condensation pressure, and evaporation pressure are measured by adding Qin _(i) of i = 1 to 3 (or more) This is a precondition, and fluctuations in Q ₍₀₎ during the measurement time lead to a decrease in estimation accuracy. Here, it is determined that Q ₍₀₎ does not change during the measurement time based on the rate of change over time (δT _out / δt, δT _R / δt) between the outside temperature and room temperature (δTout / δt, δT _R / δt). A large value means that the cooling load fluctuation is large). ΔT _out / δt = 0 (zero) and δT _R / δt = 0 (zero) during the measurement time are ideal, but since it is difficult in practice, the threshold value is determined. By reducing the “threshold value”, measurement data can be obtained when the cooling load fluctuation is small, so that the estimation accuracy is improved. While performing this series of estimation procedures, measure the operating status of another system in a room of the same use that is performing normal operation, and confirm that the air conditioning load has not changed. Do.

(2) Change in refrigerant state due to cooling and heating of liquid feeding pipe Here, as a premise of the step of calculating the estimation formula of the cooling capacity in FIGS. 2 and 3, condensation of the compressor (not shown) of the outdoor unit 1a The relationship between pressure, evaporation pressure, and enthalpy difference will be explained.
As shown in FIG. 4, when the heat quantity Qin _(i) is added to the liquid feeding pipe 1c ₍ plus in the case of cooling, minus in the case of heating), the power (power consumption ₎ changes from W _{( 0)} to W _(i) . To do.
FIG. 5 shows the refrigerant state at this time on the Mollier diagram. In the same figure, compared with the case of a normal driving | operation (FIG. 5 (a)), when the liquid feeding pipe is cooled (Qin _(i) is a plus: FIG. 5 (b)), the refrigerant | coolant state is illustrated.
As shown in FIG. 5B, when the liquid feed pipe 1c is cooled, the enthalpy of the liquid feed (expansion valve inlet) changes from h3 ₍₀₎ to h4 _(i) . Further, the condensation pressure (high pressure) changes from PH ₍₀₎ to PH _(i) , and the evaporation pressure (low pressure) changes from PL _{( 0)} to PL _(i) . The enthalpy of discharge from the compressor (not shown) of the outdoor unit 1a changes from h1 _{( 0)} ′ to h1 _(i) ′ in accordance with the change in high pressure or low pressure. At the same time, the refrigerant flow rate changes from G ₍₀₎ to G _(i), and the efficiency (total efficiency) of the compressor changes from η ₍₀₎ to η _(i) . As shown in FIG. 5A, in normal operation, the enthalpy difference Δh ₍₀₎ in the evaporator and the enthalpy difference Δhc ₍₀₎ ′ in the compressor are expressed by the following equation (1-1) and ( 1-2).
Δh ₍₀₎ = h2 ₍₀₎ −h3 ₍₀₎ ... (1-1) Δhc ₍₀₎ ′ = h1 ₍₀₎ ′ − h2 ₍₀₎ ... (1-2) Further, as shown in FIG. 5 (b), when added to cold calorie _{Qin (i)} the liquid feed pipe 1c, Qin from _{Qin (i)} content of the enthalpy difference Δhin _(i), cooling power capacity _{Q (0) (i)} by subtracting the cold amount of enthalpy difference Delta] h _(i), and the enthalpy difference Δhc in the compressor _(i) 'is the following equation (2-1), (2-2) equation, (2- 3) Formula.
Δh _(i) = h2 _(i) -h3 _(i) (2-1) equation Δhc _(i) '= h1 _(i) ' -h2 _(i) ··· (2-2) equation Δhin _(i) ′ = h3 _(i) −h4 _(i) (2-3)

Here, Δh _(i) is written as the following expression (3) using the multiplication coefficient α _(i) .
Δh _(i) = α _(i) · Δh ₍₀₎ ... (3) Compressor theoretical enthalpy difference (enthalpy difference under constant entropy s) is the high pressure, low pressure, and evaporator outlet. From the superheat control (superheat = constant), it can be obtained using the physical properties of the refrigerant.
When the compressor theoretical enthalpy difference in the normal operation is expressed as Δhc ₍₀₎ and the compressor theoretical enthalpy difference when the heat quantity Qin _(i) is added is expressed as Δhc _(i) , equations (1-2) and (2 −h _{) (0)} ′ and Δhc _(i) ′ in the expression −2) can be written as the following expressions (4-1) and (4-2).
Δhc ₍₀₎ ′ = Δhc ₍₀₎ / η ₍₀₎ ... (4-1) Δhc _(i) ′ = Δhc _(i) / η _(i) ... (4-2) Here, η ₍₀₎ is the compressor efficiency in the normal operation, and η _(i) is the compressor efficiency when the cold energy Qin _(i) is added.

(3) Cooling capacity and power When cooling quantity is not added to the liquid feeding pipe 1c, the cooling capacity Q ₍₀₎ and power W ₍₀₎ are expressed by the following formulas (5-1) and (5-2). .
Q ₍₀₎ = G ₍₀₎ · Δh ₍₀₎ ··· (5-1) Equation W ₍₀₎ = G ₍₀₎ · Δhc ₍₀₎ '= G ₍₀₎ · Δhc ₍₀₎ / .eta. ₍₀₎ ... (5-2) When cooling quantity Qin _(i) is added to liquid feeding pipe 1c, cooling capacity Q ₍₀₎ and power W _(i) are expressed by the following (6- 1) and (6-2).
Q ₍₀₎ = Qin _(i) + G _(i) · Δh _(i) = Qin _(i) + G _(i) · α _(i) · Δh ₍₀₎ ··· (6-1) Formula W _{(i )} = G _(i) · Δhc _(i) ′ = G _(i) · Δhc _(i) / η _(i) ... (6-2) Equations (5-1), (5-2) ), (6-1), and (6-2) are rearranged to obtain the following (7).
Q ₍₀₎ = Qin _(i) / {1- [alpha] _(i). (W _(i) / W ₍₀₎ ). ([Eta] _(i) / [eta] ₍₀₎ ). ([Delta] hc ₍₀₎ / [Delta] hc _{( i)} )} Equation (7)

(4) Function efficiency of compressor efficiency and enthalpy difference multiplication coefficient The compressor efficiency η is a general function form of a · (PH / PL) ^b . Further, when PH / PL is set to the compression ratio χ, the following equation (8) is obtained.
η _(i) / η ₍₀₎ = (χ _(i) / η ₍₀₎ ) ^b (8) where a and b are inherent coefficients determined by the compressor.
Here, the multiplication factor α _(i) of the enthalpy difference Δh _(i) is assumed to be α _(i) is a measured value when the amount of heat Qin _(i) is sufficiently smaller than the cooling capacity Q _(0). It is assumed that it is determined from the theoretical value. The problem here is to determine the function form of the multiplication coefficient of the enthalpy difference, such as the efficiency of the compressor.
In order to simplify the following description, it is determined by using the high pressure change rate PH ₍₀₎ / PH _(i) as in the following equation (9).
α _(i) = f (PH ₍₀₎ / PH _(i) ) (9) where f (PH ₍₀₎ / PH _(i) ) is expressed as the following (9− 1) It shall be determined as shown in the equation.
f (PH ₍₀₎ / PH _(i) ) = (PH ₍₀₎ / PH _(i) ) ^β (Equation (9-1)) Note that the superheat degree control (superheat degree at the low pressure and the evaporator outlet) = Constant), one enthalpy for determining Δh _(i) (compressor suction enthalpy h2 _(i) ) and one enthalpy for determining Δh ₍₀₎ (compressor enthalpy h2 ₍₀₎ ) Can be determined using the physical property values of the refrigerant. Therefore, as described so far, not the multiplication factor α _(i) for determining Δh _(i) based on the equation (3 ₎ , but the multiplication factor for determining the enthalpy h3 _(i) before heating / cooling. May be adopted.

(5) Cooling capacity calculation formula and test type When the above formulas (8) and (9) are substituted into formula (7), the following formula (10) is obtained.
Q ₍₀₎ = Qin _(i) / {1- (PH ₍₀₎ / PH _(i) ). ^Beta. (W _(i) / W ₍₀₎ ). (Χ _(i) / χ ₍₀₎ ) ^b (Δhc ₍₀₎ / Δhc _(i) )} (10) In the above equation (10), the cooling capacity Q ₍₀₎ to be obtained here and the exponents b and β are unknown. Therefore, in addition to the operation without adding the amount of cold heat to the liquid feeding pipe 1c, three kinds of cold heat quantities of the cold heat quantity Qin ₍₁₎ , the cold heat quantity Qin ₍₂₎ and the cold heat quantity Qin ₍₃₎ were added to the liquid feeding pipe 1c. When the operation is performed, the cooling capacity Q ₍₀₎ can be estimated by solving the following three simultaneous equations.
Q ₍₀₎ = Qin ₍₁₎ / {1- (PH ₍₀₎ / PH ₍₁₎ ) ^β · (W ₍₁₎ / W ₍₀₎ ) · (χ ₍₁₎ / χ ₍₀₎ ) ^b (Δhc ₍₀₎ / Δhc ₍₁₎ )}
Q ₍₀₎ = Qin ₍₂₎ / {1- (PH ₍₀₎ / PH ₍₂₎ ) ^β · (W ₍₂₎ / W ₍₀₎ ) · (χ ₍₂₎ / χ ₍₀₎ ) ^b (Δhc ₍₀₎ / Δhc ₍₂₎ )}
Q ₍₀₎ = Qin ₍₃₎ / {1- (PH ₍₀₎ / PH ₍₃₎ ) ^β. (W ₍₃₎ / W ₍₀₎ ). (Χ ₍₃₎ / χ ₍₀₎ ) ^b (Δhc ₍₀₎ / Δhc ₍₃₎ )}
By solving this, the cooling capacity Q ₍₀₎ , b, β can be obtained. The flow in the case of solving with an arithmetic unit is shown in FIG. These can be programmed in advance and installed in a personal computer or recorded in an appropriate storage medium.
If the above results are calculated to be lower than the rated capacity, consider measures to increase the number of PACs and heat generated by OA equipment, etc. If the values are calculated to be higher, load and air conditioning such as relocation of the PAC to another load range. Measures can be considered so that is appropriate.

Table 1 is an example of a cooling capacity calculation tool, and each column of this table (data table in the case of computer use) includes measured values (heat addition, power consumption, pressures on the high and low pressure sides of the compressor) and Enter or enter the calculated values (compression ratio and enthalpy difference) for each of the four operating modes during normal operation and three operations. Here, compression ratio = condensation pressure / evaporation pressure, and measurement of measured evaporation pressure (pressure gauge PL that measures the pressure of the low-pressure refrigerant) and condensation pressure (pressure gauge PH that measures the pressure of the high-pressure refrigerant) Use the value. In Table 1, the remarks column confirms the source of data to be entered or entered.
The actual operation in Table 1 can be considered as follows. If the measured values in Table 1 are filled, the subsequent calculations can be completed in a short time. Therefore, the measurement may be performed at a PAC system trial operation or a site (onsite) in operation, and the equation may be solved at an office or the like. Alternatively, a measurement value may be manually input to a mobile terminal such as a mobile phone, and a remote server may be used to calculate and return the result to the mobile terminal. The processing of the "calculation ability estimation equation" in FIG. 2 may be performed before determiner of (compared to the threshold of the outside air temperature T _out and room T _R).

(6) Prediction accuracy of cooling capacity In order to check the estimation accuracy of the cooling capacity obtained by the above method, in particular the validity of the function form of the multiplication factor of the enthalpy difference, the water heat source instead of the outdoor unit 1a. The result implemented with the test apparatus using a heat pump (water cooling chiller) is demonstrated.
FIG. 6 shows a system of a test apparatus 40 using a general-purpose water-cooled chiller. Table 2 shows the specifications of the components.
FIG. 6 schematically shows a system of each device and refrigerant piping in the test apparatus 40, and in order to cool and heat the liquid feeding pipe 41, a heat source apparatus (heat pump apparatus) as shown in FIG. ) 42 is used. Moreover, it replaces with the tube 3 of FIG. 1, and uses the heat exchanger 42a. The refrigerant that has passed through the heat exchanger 42 a passes through the expansion valve 43, goes from the evaporator 44 to the accumulator 45, the compressor 46, and the condenser 47. The flow rate of the refrigerant flowing through the liquid feeding pipe 41 is measured by the mass flow meter 48. The cold water cooled by the evaporator 44 is heated by the heat exchanger 50 by the electric heater 49 serving as a simulated load in the cooling mode and returned to the evaporator 44. The condensing pressure of the general-purpose water-cooled chiller flowing through the liquid feeding pipe 41 is measured by a pressure gauge 51, the evaporation pressure is measured by a pressure gauge 52, the evaporator inlet temperature is measured by a thermometer 53, and the evaporator outlet temperature is Measured by the thermometer 54, and the electric power of the compressor 46 is measured by the wattmeter 55.
The amount of cold Qin added to the general-purpose water-cooled chiller via the heat exchanger 42a was determined by a heat source water flow meter (not shown) and a thermometer (not shown). The refrigerating capacity Q (true value) to be estimated here can be obtained from the inlet / outlet temperature difference and flow rate of the cold water of the evaporator 44.

Tables 3 and 4 show the results of the estimated refrigeration capacity Q ₍₀₎ and the estimated accuracy (Q ₍₀₎ / Q). Table 3 shows a case where the liquid feeding pipe 41 is cooled, and Table 4 shows a case where the liquid feeding pipe 41 is heated. FIG. 7 shows the change over time in the operating state of the test apparatus 40 when the liquid feeding tube 41 is cooled. After the amount of cold heat Qin _(i) added to the liquid feeding pipe 41 is changed in three stages, the temperature and flow rate of the cooling water at the inlet of the condenser 47 and the temperature and flow rate of the cold water at the inlet of the evaporator 44 become constant in each stage. The operating state of was measured. As can be seen from the estimated refrigeration capacity column of Table 3, the prediction accuracy of the refrigeration capacity is ± 6%, and Table 4 is ± 5%, and can be predicted with sufficient accuracy when the liquid feeding pipe 41 is cooled and heated. . In addition, it was confirmed that the function form of the multiplication coefficient of the enthalpy difference as in the above equation (9-1) was appropriate. The difference between the capacity Q ₍₀₎ estimated by the simultaneous equations and the rated capacity is expressed as estimated accuracy Q ₍₀₎ / Q in the table. Q ₍₀₎ shows the case of normal operation, Q ₍₀₎ = 2.8 kW when measured by cooling, and Q ₍₀₎ = 2.4 kW when measured by heating.

  The present invention is not limited to the embodiment described above, and can be implemented. For example, the present invention can be applied to a PAC having one indoor / outdoor unit. As the heat source device, a Peltier element or the like can be used as long as it can accurately measure heating and cooling.

1 is a schematic configuration diagram according to an embodiment of the present invention. The flowchart of the cooling capacity estimation procedure which concerns on embodiment of this invention. The flowchart of the calculation for derivation | leading-out of the cooling capacity estimation formula which concerns on embodiment of this invention. The figure which shows the cycle change during a measurement in implementing embodiment of this invention. The schematic diagram of the change of a refrigerant | coolant state when the amount of cold heat Qin _(i) is added to the liquid feeding pipe in implementing embodiment of this invention. FIG. 2 is a test apparatus diagram for verifying the accuracy of the embodiment of the present invention. The figure which shows the time-dependent change of the driving | running state of a test apparatus at the time of verifying the precision of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 PAC system 1a Outdoor unit 1b Indoor unit 1c Liquid supply pipe 2 Heat source apparatus 3 Tube

Claims (4)

Cooling capacity of an air-conditioning system using a packaged air conditioner in which an outdoor unit equipped with a capacity-controlled compressor and an outdoor heat exchanger and an indoor unit equipped with an indoor heat exchanger are connected by refrigerant piping. A method of measuring,
Heating or cooling the liquid supply pipe through which refrigerant is sent from the outdoor unit to the indoor unit, and estimating the cooling capacity from the following formula based on the data of changes in power consumption, condensation pressure and evaporation pressure of the compressor accordingly Like
From the enthalpy difference Δh _(i) excluding the enthalpy difference for the heating amount or the cooling amount after heating or cooling the liquid feeding pipe from the enthalpy difference in the evaporator , the multiplication factor α _(i) is expressed as Δh _(i) = is defined as _{α (i) · Δh (0} ),
The method for measuring the cooling capacity of an air conditioning system using a packaged air conditioner is characterized in that the cooling capacity Q ₍₀₎ is estimated by the following equation.
Cooling capacity Q ₍₀₎ = Qin _(i) / {1- [alpha] _(i). (W _(i) / W ₍₀₎ ). ([Eta] _(i) / [eta] ₍₀₎ ). ([Delta] hc ₍₀₎ / Δhc _(i) )}
Qin _(i) is the amount of heat added to the liquid delivery pipe,
(W _(i) / W ₍₀₎ ) is the rate of change in power consumption when the amount of heat Qin _(i) is added to the liquid delivery pipe ,
(Η _(i) / η ₍₀₎ ) is the rate of change in the efficiency of the compressor when the heat quantity Qin _(i) is added to the liquid feed pipe ,
(Δhc ₍₀₎ / Δhc _(i) ) is a ratio of the compressor theoretical enthalpy difference when the heat quantity Qin _(i) is added to the liquid feeding pipe . Cooling capacity of an air-conditioning system using a packaged air conditioner in which an outdoor unit equipped with a capacity-controlled compressor and an outdoor heat exchanger and an indoor unit equipped with an indoor heat exchanger are connected by refrigerant piping. A method of measuring,
Heating or cooling a liquid supply pipe through which refrigerant is sent from the outdoor unit to the indoor unit, and estimating the cooling capacity based on data of changes in power consumption, condensing pressure, and evaporation pressure of the compressor according to the heating pipe .
In obtaining the change data, the heating amount after heating or cooling the liquid feeding tube or the enthalpy difference for the cooling amount is used, and at least after the liquid feeding tube is heated or cooled from the enthalpy difference in the evaporator. From the enthalpy difference excluding the enthalpy difference for the heating amount or cooling amount, the multiplication factor α _(i) is defined and its function form is determined ,
3. The package type according to claim 2, further comprising: a process for executing the next operation in the order of one of the procedure 1 </ b> A and the procedure 1 </ b> B → the remaining one of the procedure 1 </ b> A and the procedure 1 </ b> B → the procedure 3 → the procedure 4. A method for measuring the cooling capacity of an air conditioning system using an air conditioner.
Procedure 1A: Enthalpy difference Δh _(i) obtained by subtracting the enthalpy difference for the heating amount or the cooling amount after heating or cooling the liquid feeding pipe from the enthalpy difference in the evaporator, using the multiplication factor α _(i) It is defined as
Δh _(i) = α _(i) · Δh ₍₀₎
Δh ₍₀₎ is the enthalpy difference procedure 1B in the evaporator of the indoor unit in normal operation: From the general characteristics of the refrigeration cycle, the multiplication factor α _(i) is the change rate PH ₍₀₎ of the pressure of the high-pressure gas. / PH _(i) and the index β are defined as follows:
α _(i) = (PH ₍₀₎ / PH _(i) ) ^β
Where PH is the condensation pressure.
Step 3: Cooling capacity Q ₍₀₎ , power W _(0), and compressor efficiency η ₍₀₎ representing the operating state of the air conditioning system when the amount of cooling heat is not added to the liquid feeding pipe using the formula of step 1A And compressor theory enthalpy difference Δhc ₍₀₎ ,
Cooling capacity Q _(i) , power W _(i) , compressor efficiency η _(i) and compressor theory representing the operating state of the air conditioning system when heating amount or cooling amount Qin _(i) is added to the liquid feed pipe Enthalpy difference Δhc _(i) ,
And the following formula is obtained under the condition of Q ₍₀₎ = Q _(i) .
Q ₍₀₎ = Qin _(i) / {1- [alpha] _(i). (W _(i) / W ₍₀₎ ). ([Eta] _(i) / [eta] ₍₀₎ ). ([Delta] hc ₍₀₎ / [Delta] hc _{( i)} )}
Procedure 4: The following formula is obtained from the formula of Procedure 1B and a · (PH / PL) ^b which is a general function form of the compressor efficiency η _(i) .
Q ₍₀₎ = Qin _(i) / {1- (PH ₍₀₎ / PH _(i) ). ^Beta. (W _(i) / W ₍₀₎ ). (Χ _(i) / χ ₍₀₎ ) ^b (Δhc ₍₀₎ / Δhc _(i) )}
Where a and b are specific coefficients determined by the compressor, PH is a condensation pressure, PL is an evaporation pressure, and χ is a compression ratio (PH / PL). The power consumption of the compressor, the condensing pressure, measured with a power meter provided on the power line that supplies power to the compressor, a pressure gauge provided on the refrigerant discharge pipe of the compressor, and a pressure gauge provided on the refrigerant suction pipe of the compressor, Using each value of evaporation pressure,
The method for measuring the cooling capacity of an air conditioning system using a package type air conditioner according to claim 2 , wherein at least a heating amount or cooling amount Qin _(i) for the liquid feed pipe is determined. Using a package-type air conditioner that connects an outdoor unit equipped with a capacity-controlled compressor and an outdoor heat exchanger and an indoor unit equipped with an indoor heat exchanger with a refrigerant pipe, the outdoor unit is converted into an indoor unit. An air conditioning system using a packaged air conditioner that heats or cools a liquid supply pipe to which a refrigerant is sent and estimates cooling capacity based on data of changes in power consumption, condensation pressure, and evaporation pressure of the compressor accordingly. A measuring device for carrying out the cooling capacity measuring method,
A tube that can be attached to the pipe wall of the liquid feeding pipe, and is sheathed with a heat insulating material for applying cold or warm heat to the liquid feeding pipe;
A heat source device separate from the tube;
The heat source device includes a thermostatic bath filled with a liquid, a pump that supplies the liquid from the thermostatic bath to the tube, and a heat exchanger that heats or cools the liquid in the thermostatic bath. A cooling capacity measuring device.

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