KR0152287B1 - Refrigerant cycle optimum design control method of airconditioner - Google Patents

Abstract

According to the present invention, in designing a refrigerant cycle of an air conditioner, a predetermined input data is prepared for each component of a refrigerant cycle, the input data are calculated, the calculated results are compared, and the error is determined according to the comparison result. The design and the designed result can be grasped through the screen at a glance, so that it is easy to design the refrigerant cycle of the air conditioner and at the same time, it can be designed under the optimal conditions.

Description

Refrigerant cycle optimal design control method of air conditioner.

1 is a refrigerant cycle used in the present invention.

2 is a pressure-enthalpy diagram used in the present invention.

3 is a flowchart of a refrigerant cycle optimal design control method applied to the present invention.

4 is a refrigerant cycle design applied to the present invention.

5 is a pressure-enthalpy diagram applied to the present invention.

* Explanation of symbols for main parts of the drawings

1: compressor 2: condenser

3: dryer 4: capillary

5: evaporator 6: accumulator

The present invention relates to a control method of the optimum design control of the refrigeration cycle of the air conditioner, and in particular, in the air conditioner using the vapor compression refrigeration cycle, each component for the compressor, condenser, capillary, evaporator can be created and modified to be the optimum The present invention relates to a method for optimal design control of a refrigeration cycle of an air conditioner that enables easy design while grasping the results.

Currently used air conditioners for homes and businesses are steam compression refrigeration cycle, consisting of a compressor, an evaporator, a condenser, a capillary tube, a heat exchanger blower, and other accessories, but in recent years, the demand for energy-saving home appliances has increased. Therefore, the importance of developing high efficiency refrigeration system is greatly added.

Therefore, in order to improve the performance of the air conditioner, the high efficiency through the optimal design of the component parts constituting the system and the balance between the components by identifying the operating state and performance of the system according to each design factor and operating conditions of the system Optimal design technology of the whole system is required, which can be accessed relatively easily by mathematically accurately modeling the actual system and components, and through this, the unskilled person can change the design of the air conditioner using the computer. Performance can be predicted at design stage and development efficiency can be increased.

However, in order to optimize the design of the refrigeration system consisting of the steam compression refrigeration cycle, a computer is used. At this time, a large amount of input data must be created, and the calculation results are enormous. It also had a difficult point to use easily.

Therefore, an object of the present invention is to provide an air conditioner that makes it easier to design the optimum conditions of each component by modifying and supplementing the conditions of each component such as heat exchanger and compressor of the refrigeration cycle of the air conditioner. Another object of the present invention is to show the input data according to the design of the refrigeration system with the components of the system so that the input data can be grasped at a glance, and each component The results of the calculation are also presented in the form of pressure-enthalpy diagram cycle to show the key performance data and to provide a control method for the refrigeration cycle design of the air conditioner.

In order to realize the above object, input conditions of elements such as compressor, evaporator, condenser, capillary, blower and pipe of refrigeration system of air conditioner are set, and the calculated conditions are calculated to calculate the predetermined value. Comprising a pre-processing step to create and process the conditions of each element while comparing the judgment and the post-processing step to ensure that the processing results in the pre-processing step at a glance.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a refrigeration cycle used in the present invention,

2 is a pressure-enthalpy diagram used in the present invention, wherein the refrigerating system compresses a refrigerant having a low temperature and a low pressure to compress it into a state of high temperature and high pressure, and a high temperature and high pressure introduced from the compressor (1). A condenser (2) for dissipating heat to the refrigerant, a dryer (3) for drying the liquid contained in the liquid refrigerant at a relatively low high temperature and high pressure flowing out of the condenser (1), and the dryer (3). A capillary tube 4 for reducing the high temperature and high pressure refrigerant flowing therein into a low temperature and low pressure refrigerant, an evaporator 5 for receiving the low temperature low pressure refrigerant flowing out of the capillary tube 4 and absorbing the surrounding heat; It consists of an accumulator 6 which separates liquid from the refrigerant | coolant heat-exchanged with surroundings in (5), and sends it to the said compressor (1).

In the refrigerating cycle configured as described above, as shown in the enthalpy diagram of FIG. 2, when the compressor 1 receives power from the outside and discharges the low temperature low pressure refrigerant to the high temperature high pressure refrigerant c, the high temperature high pressure refrigerant Flows into the condenser 2 in the state of the refrigerant d, and after dissipating heat to the condenser 2, exits the refrigerant e to the outlet of the condenser 2, and passes through the dryer 3. (f) enters the capillary (4).

At this time, while the refrigerant passes through the capillary tube 4, the pressure and flow rate are adjusted to enter the evaporator 5 in the state of the refrigerant g, and the evaporator 5 absorbs heat from the surroundings, and then the refrigerant a The output of the refrigerant (a) is output in the state is made of a repetitive process flowing into the compressor (1) through the accumulator (6), the refrigerant (b).

As shown in FIG. 2, the refrigeration cycle is composed of a high pressure stage composed of a compressor condenser and a capillary tube, and a low pressure stage of an evaporator. The refrigeration system analysis model calculates a low pressure stage after completion of the calculation of the high pressure stage. The system calculates iteratively until equilibrium is achieved, enabling optimal design of cooling and heating operations. Therefore, the input data for using the analysis model of the refrigeration system is as follows. The degree of superheat at the inlet of the compressor (1). Flow coefficient of capillary tube 4 and number of capillary tube 4 (or supercooling / dryness of condenser outlet). Air temperature and relative humidity at the inlet of the evaporator (5) and condenser (2). Heat loss in piping and compressor (1). And the saturation temperature corresponding to the pressure of the refrigerant at the compressor inlet / outlet. FIG. 3 is a flowchart of a method for controlling a refrigerant cycle optimal design applied to the present invention, and an input data preparation step of preparing input data for a high pressure step mountain consisting of a compressor, a condenser, and a capillary tube on each component side of a refrigerant cycle (30) ), And the high pressure stage balance step 31 for performing the high pressure stage balance of the data, that is, the compressor, the condenser, the capillary tube, etc. created in the input data creation step 30, and the high pressure stage compressor in the high pressure stage balance step 31. Compressor calculation step 32 for calculating the power consumption and refrigerant flow rate corresponding to the condition (saturation temperature of the compressor inlet / outlet), and after calculating the supercooling degree of the condenser outlet, the refrigerant flow rate ( Given the superheat degree of the outlet calculated at the condenser, the flow coefficient of the capillary and the number) are calculated by the condenser, the capillary relation step 33, the compressor calculation step 32, and the A refrigerant flow rate comparing step 34 in which the refrigerant flow rate (or a given subcooling degree) calculated in the accumulator and capillary calculation step 33 is compared with the refrigerant flow rate calculated by the compressor (or the subcooling degree calculated at the outlet of the condenser); The refrigerant flow rate determination step 35 for determining whether the refrigerant flow rate calculated in the refrigerant flow rate comparing step 34 matches the given error range and the refrigerant flow rate calculated in the refrigerant flow rate determination step 35 do not coincide with the given error range. Otherwise, the pressure correction step 36 of the high pressure stage is repeated until the pressure range of the high pressure stage is corrected and the refrigerant flow rate calculated in the refrigerant flow determining stage 35 is equal to the given error range. And a low pressure stage equilibrium step 37 for determining whether the low pressure stage of the pipe is equilibrated, an evaporator superheat degree calculation step 38 for calculating the superheat degree of the evaporator inlet in the low pressure stage equilibrium step 37, and The evaporator superheat comparison step 39, which compares the error by comparing the superheat degree calculated in the evaporator superheat calculation step 38 and the given value, and the error calculated in the evaporator superheat comparison step 39, fall within the given error range. If it does not coincide, the evaporator inlet air temperature correction step 40 repeatedly calculates the air temperature at the evaporator inlet until it converges and the evaporator inlet air temperature correction step 40 is within a given error range. In case of coincidence, the temperature range of the evaporator inlet air temperature is determined (41) and the evaporator inlet air temperature is determined (41). If it does not match, the evaporator pressure correction step 42 to go back to the initial stage while repeating the correction of the pressure of the evaporator, and the evaporator inlet air temperature determination step ( 41, a result output step 43 for outputting a calculation result if the error range is matched. 4 is a refrigerant cycle showing the input to the optimum design control method applied to the present invention. 5 is a pressure-enthalpy diagram showing the output of the optimum design control method applied to the present invention.

Referring to the effect of the present invention as described above are as follows. First, a predetermined input data is prepared for the compressor 1, the condenser 2, and the capillary tube 4, which are high-pressure stages, which are the components of the refrigerant cycle, in a state in which the designer configures the refrigerant cycle to be designed. The input data is processed while inputting it to the computer to be designed, which is a preprocessing step. That is, the computer goes to the high pressure stage balance step 31, and the compressor calculation step (32) is performed so that the input data for the input refrigerant cycle is balanced. ), Calculate the power consumption and refrigerant flow rate corresponding to the saturation temperature of the inlet and outlet of the compressor (1), and then go to the condensation machine stage (33) and calculate the supercooling of the outlet of the condenser (2). Go to the capillary relation step 34, if the specifications of the capillary tube 4, given the refrigerant flow rate, that is, the superheat of the outlet of the condenser 2, the flow coefficient and number of the capillary tube 4 Will be calculated.

When the calculation is completed as described above, the computer goes to the refrigerant flow determination step 35 and compares the given refrigerant flow rate (or given subcooling degree) with the refrigerant flow rate calculated by the compressor (or the subcooling degree calculated by the condenser). It is determined whether it is within an error range.

If the refrigerant flow rate calculated in the refrigerant flow rate determination step 35 is in the given error range, the flow goes to the low pressure stage balancing step 37, which is an evaporator and a pipe, and the refrigerant flow rate calculated in the refrigerant flow rate determination step 35 is given the error range. If not, the computer will go to the condenser pressure correction step 36 to correct the pressure of the evaporator and eventually repeat the process while correcting the pressure in the high pressure stage until the corrected refrigerant flow is within the margin of error.

When the calculation of the high pressure stage is completed as described above and the balance of the high pressure stage is completed, the computer goes to the low pressure stage equilibrium step 37, and the superheat and air temperature of the evaporator and the pipe are calculated. 38), the superheat degree of the inlet side of the compressor (1) is calculated, and the calculated superheat degree goes to the evaporator superheat comparison step 39 to compare with the superheat degree of the given evaporator, and the result of the comparison If not within the range of a predetermined error, the computer corrects the air temperature at the inlet side of the evaporator 5 and repeatedly calculates the superheat until it is within a predetermined error range. When the range is reached, the computer goes to the evaporator inlet air temperature determination step 41 and compares the air temperature at the inlet of the evaporator 5 with the corrected air temperature. If it is determined that it is in the difference range and not within a predetermined error range, the computer goes to the pressure correction step 42 of the evaporator, corrects the pressure of the low pressure stage, and repeats the operation again from the beginning, and the evaporator inlet air temperature determination step At 41, if the air temperature at the inlet of the evaporator is within the predetermined error range, go to the result output step 43, and complete the result output to consume the refrigeration capacity and capacity coefficient, the compressor and the blower motor. Power, sensible heat ratio to total heat transfer rate, dry / wet bulb temperature of heat exchanger outlet air, pressure drop on air / refrigerant side, entropy efficiency and volumetric efficiency of compressor, heat exchanger effectiveness and UA value, capillary flow coefficient and number, cycle The data on the state of the refrigerant in the phase is printed out.

As shown in FIGS. 4 and 5, the refrigerant system processed in the pretreatment step shows the components of the refrigerant system and the pressure-enthalpy diagram on the screen as shown in FIGS. It also allows you to create and modify the data, and also displays important input values on the screen so that the overall input data can be easily identified.

When the calculation is completed, the refrigerating cycle is shown on the pressure-enthalpy diagram as shown in FIG. 5 so that the calculation result and the cycle operating state processed by the preprocessor can be identified at a glance. If you select the main part, you can see the thermodynamic properties (pressure, temperature, enthalpy, overheat, subcooling, dryness, etc.) of the refrigerant in that part, and the refrigeration capacity, performance factor, power consumption and air inlet / outlet temperature of the refrigeration system. The lights can also be displayed on the screen, allowing the optimal design of the refrigeration cycle.

As described above, the present invention enables the calculation, preparation, and modification of the thermodynamic properties of the refrigerant in each component of the refrigeration cycle of the air conditioner, the power consumption coefficient of the refrigeration system of the refrigeration system, the inlet and outlet temperature of the air, and the like. It will provide the advantage to design in the optimal condition.

Claims (2)

The input data creation step of preparing input data for the high pressure step mountain consisting of each component of the refrigerant cycle, that is, the compressor, the condenser, and the capillary tube, and the high pressure stage equilibrium such as the compressor, condenser, capillary tube, etc. High pressure stage equilibrium step to perform, the low pressure stage equilibrium step of performing the balance of the low pressure stage, the evaporator and the piping unit when the calculation of the high pressure stage is completed in the high pressure stage equilibrium step, and the result when the low pressure stage equilibrium stage is completed Cooling cycle control design method of the air conditioner consisting of a result output step of outputting. The method of claim 1, wherein the high pressure stage equilibrium step includes a compressor calculation step 32 for calculating the refrigerant flow rate in the high pressure stage compressor, a supercooling degree at the condenser outlet, and a condenser for calculating the refrigerant flow rate when the capillary specification is given; A refrigerant flow rate comparison step 34 for comparing the refrigerant flow rate calculated in the capillary relation calculation step 33, the compressor calculation step 32, the condenser and the capillary calculation step 33 with the refrigerant flow rate calculated by the compressor; The refrigerant flow rate determination step 35 and the refrigerant flow rate determination step 35 which determine whether the refrigerant flow rate calculated in the refrigerant flow rate comparison step 34 correspond to the given error range coincide with the given error range. Otherwise, the pressure correction step 36 of the high pressure stage corrects the pressure of the high pressure stage, and the low pressure stage balance step of performing the low pressure stage equilibrium of the evaporator and the pipe calculates the superheat degree of the evaporator inlet. If the error calculated in the evaporator superheat calculation step 38 comparing the error, the evaporator superheat comparison step 39, and the error calculated in the evaporator superheat comparison step 39 does not match the given error range, the air at the evaporator inlet When the evaporator inlet air temperature correction step 40 corrects the temperature and the superheat degree calculation error in the evaporator inlet air temperature correction step 40 coincides with a given error range, the air temperature at the inlet of the evaporator and the corrected air temperature are determined. The evaporator inlet air temperature determination step (41) to be compared and judged, and the evaporator pressure correction step (42) to correct the pressure of the evaporator if the error range does not match in the evaporator inlet air temperature determination step (41). Refrigerant cycle optimal design control method of an air conditioner.