JPS59119151A - Method of detecting output from refrigerator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting the output value of a refrigerator used in an air conditioner or the like.

Generally, in air conditioners, etc., when cooling, the output value of the refrigerator is detected and the operation status of the refrigerator is controlled according to the air conditioning status. The temperature difference between the inlet temperature and the outlet temperature of the cold water is determined, the flow rate of the cold water is determined, and the product of the flow rate and the temperature difference is calculated, thereby detecting the output value of the refrigerator.

However, such a method requires an expensive flow meter, resulting in an increase in the cost of the device.

In addition, in the case of a turbo chiller, find the vane opening,
This is used to approximately detect the output value of the refrigerator, but on the Mollier diagram showing the relationship between the enthalpy and pressure of the refrigerant, the temperature of the cooling water for the condenser or the temperature of the cooling water by the refrigerator If the temperature of the chilled water changes, the load condition of the compressor in the refrigerator will change, so the relationship between the vane opening and the output value of the refrigerator will not be equal, resulting in the disadvantage that the output value cannot be detected accurately. It is occurring.

The present invention has been made in view of the drawbacks of the conventional refrigerant, and the first purpose is to obtain the value of the difference between the evaporation pressure and the condensation pressure of refrigerant in a refrigerator, and to calculate the value of this difference. A method for detecting a refrigerator output is provided, in which a correction value is calculated accordingly, and a value indicating the vane opening of the refrigerator is multiplied by the correction value to detect an output value of the refrigerator.

The second purpose is to find the difference between the temperature of the condenser cooling water in the refrigerator and the temperature of the cold water cooled by the refrigerator, and then find a correction value according to this difference. The present invention provides a method for detecting the output of a refrigerator, which detects the output value of the refrigerator by multiplying a value indicating the opening degree of the vane of the refrigerator by a correction value.

Furthermore, the third purpose is to determine the difference between the wet bulb temperature of the outside air and the temperature of the cold water cooled by the refrigerator, and then determine a correction value according to this difference to determine the opening of the refrigerator vane. The present invention provides a method for detecting the output of a refrigerator, which detects the output value of the refrigerator by multiplying a value indicating the temperature by a correction value.

Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

Figure 1 is an instrumentation diagram when a refrigerator is applied to an air conditioner. The cold water returned from the air conditioning load AL such as a fan coil unit is passed through the header HDl to the evaporator EV of the refrigerator.
AI passes through EVA2 and is cooled, and pump PP
The compressor is compressed by compressors CPI, CP2, and condensers CDS1, C, and is supplied to the air conditioning load AL via header HD2.
DS 2, expansion valve EVI, EV2 and evaporator EVA
The kelp is composed of EVA 2.

The gaseous refrigerant that has become high temperature and high pressure by Retsusa CPI and CP2 is transferred to condensers CDS 1 and CDS 2.
It is cooled by the cooling water from cooling towers CTI and CT2, and becomes a low-temperature, high-pressure liquid.
, low temperature, low pressure gaseous source through EV2, evaporator E
After the cold water is cooled in the VAI and EVA2, it becomes a high temperature, low pressure gas and is returned to the compressors CPI and CP2.

Also, a temperature sensor T1 for measuring the temperature of cold water cooled by the refrigerator, a temperature sensor T2 and a humidity sensor H1 for determining the wet bulb temperature of outside air, and a condenser CDS 1.
．． Temperature sensor T3 for measuring the temperature of cooling water for CDS 2. T4, a pressure sensor Pi for measuring the evaporation pressure of the refrigerant, P2, a pressure sensor P3 for measuring the condensation pressure of the refrigerant. P4 is provided, and these outputs are given to the controller CNT, and the compressor CP
I, CP2's 7th opening! The signals are also given to the controller CNT, and based on these, the controller CNT detects the output value of the refrigerator, and according to the air conditioning status signal given from others,
Compressor CPI, CP2 and pump PPI, PP
It is designed to control the operating conditions of No. 2.

However, the vane opening degree signal is similarly used in the first to third inventions, but in the first invention, only the output of the pressure sensor Ps-P4 is used, and in the second invention, the output of the temperature sensor T1. T3. In the third invention, only the output of temperature sensor 'f1. Only the outputs of T2 and humidity sensor H1 are used.

FIG. 2 is a functional block diagram of a detection circuit corresponding to the first invention, which subtracts the evaporation pressure signal PE from the pressure sensor P1 or P2 and the condensation pressure signal pc from the pressure sensor P3 or P4. After calculating the difference between the two, the correction value generator CNG generates a correction value signal, and the vane opening signal OD from the compressor CP1 or CF2 is multiplied by the correction value signal. The output value signal DO is obtained by multiplying the output value signal DO by the device MUL.

As shown in FIG. 3, the correction value generator CNG calculates the difference lP between the evaporation pressure signal PE and the condensation pressure signal PC.
After determining the correction value signal α corresponding to the E-Pc1O value, a memory or the like may be used to store this in a table form, and the correction value signal α may be read out by specifying an address based on the difference value.

In this case, the evaporation pressure signal PE is the compressor CP.
The condensing pressure signal Pc corresponds to the input amount of compressors I and CP2, and the condensing pressure signal Pc corresponds to the output amount of compressors CPI and CP2. , compressor CP1. It has a correlation with the output value of CP2, and if the curve shown in Fig. 3 is experimentally determined and the correction value signal α is determined, then by multiplying this by the vane opening signal OD, the accurate value can be determined. An output value signal DO can be determined.

In addition, the configuration of FIG. 2 is similar to that of the controller CNT in FIG.
In reality, it is preferable to realize the functions shown in Fig. 2 using a microprocessor, memory, input/output circuit, etc. Fig. 4 corresponds to the second invention. This is a block diagram similar to that of FIG. 2, except that the subtractor SU provides the cooling water temperature signal Tw from the temperature sensor T3 or T4 and the cooling water temperature signal Tc from the temperature sensor T1. Although it is similar to the figure, in this case the correction value generator CNG generates the correction value signal α according to the value of the difference between the coolant temperature signal TW and the chilled water temperature signal Tc.

In addition, in FIG. 4, the chilled water temperature signal Tc corresponds to the evaporation pressure signal PK in FIG. 2, and the cooling water temperature signal TW corresponds to the condensing pressure signal Pc in FIG. 2. Similar results are obtained.

FIG. 5 is a block diagram similar to FIG. 2 corresponding to the third invention), the outside air temperature signal To from the temperature sensor T2,
The outside air humidity signal HO from the humidity sensor H1 is input to the computing unit OP.
It is the same as in Fig. 4, except that the wet bulb temperature of the outside air is determined based on both signals, and a signal indicating this is sent to the subtractor SUB. .

In this case, since the wet bulb temperature of the outside air indicates the cooling capacity of the cooling towers CTI and CT2 in FIG. 1, the output of the computing unit OP corresponds to the cooling water temperature signal TW in FIG. A similar result is obtained.

Therefore, the output value of the refrigerator can be accurately detected only by using relatively inexpensive pressure sensors, temperature sensors, humidity sensors, etc., without using an expensive flow meter.

However, in the first invention, the condenser CD5s.

The input side pressure and output side pressure of CDS 2 are equal to
And the input side pressure and output side pressure of evaporators EVAI and EVA2
j pressure is equal to tI, so the pressure sensors PI and P2 are connected to the evaporator EVA1. Provided on the input side of EvA2, or pressure + 7 P 3 , P 4 Total condenser CDS 1
, may be provided on the output side of the CDS 2, and in the third invention, the wet bulb temperature of the outside air may be directly measured by the wet bulb temperature sensor without using the temperature sensor T2, the humidity sensor H1, and the arithmetic unit OP. Various modifications are possible.

As is clear from the above explanation, according to the present invention, since the refrigerator output value can be accurately detected using an inexpensive sensor, the equipment cost can be reduced, and the refrigerator output value can be detected in various applications. Significant effects can be obtained when used for detection.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Figure 1 is an instrumentation diagram, Figure 2 is a functional block diagram of a detection circuit corresponding to the first invention, Figure 3 is a diagram showing a correction value signal, and Figure 4 is a diagram showing a correction value signal. The figure is a block diagram similar to FIG. 2 corresponding to the second invention, and FIG. 5 is a block diagram similar to FIG. 2 corresponding to the third invention. CPI, CP2* * m-II: +7 Gretusa, C
D5I, CD52 ... condenser, EVAI, E
VA2 Fist...Evaporator, CTI, Cr2/Intimidation...Cooling tower, T1~T4e*++/Temperature sensor, Hl
・Fist: Humidity sensor, P1 to P4: Pressure sensor, oD@Φ: Vane opening signal, PE: Evaporation pressure signal, Pc: Condensation pressure signal, Tw... Cooling water temperature signal, TC...Cold water temperature signal, To...
Outside temperature signal, Ho...Outside humidity signal, SUB...
...Subtractor, during cNG...Correction value generator, MUL...
...N power multiplier, OP... Arithmetic unit. Patent applicant: Yamatake Honeywell Co., Ltd. Agent: Masaki Yamakawa (Iυ) (1 person) Figure 1, Figure 2. Figure 3 BeυO Figure 5

Claims (3)

[Claims] (1) After determining the value of the difference between the evaporation pressure and condensation pressure of the refrigerant in the refrigerator, a correction value is determined according to the value of the difference, and the correction value is applied to the value indicating the vane opening of the refrigerator. A method for detecting the output of a refrigerator, characterized in that the output value of the refrigerator is detected by multiplying the output value of the refrigerator. (2) After determining the value of the difference between the temperature of the cooling water for the condenser in the refrigerator and the temperature of the cold water cooled by the refrigerator, a correction value is determined according to the value of the difference, and A method for detecting a refrigerator output, characterized in that an output value of the refrigerator is detected by multiplying a value indicating a vane opening degree by the correction value. (3) After determining the value of the difference between the wet bulb temperature of the outside air and the temperature of the cold water cooled by the refrigerator, a correction value is determined according to the value of the difference, and a value indicating the vane opening degree of the refrigerator. A method for detecting a refrigerator output, characterized in that the output value of the refrigerator is detected by multiplying the correction value by the correction value.