JP3444360B2 - Constant temperature and constant room equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant-temperature and constant-humidity apparatus that generates constant-temperature and constant-humidity air with high precision and distributes the constant-temperature and constant-humidity air through a duct. [Prior Art] FIGS. 4 and 5 are a block diagram and a psychrometric chart for explaining a relative humidity estimating method, for example, of a conventional air conditioner humidity control device disclosed in Japanese Patent Publication No. Hei 4-46772. In FIG. 4, reference numeral 1 denotes an air conditioner, 2 denotes a room in which the air conditioner 1 is installed, 3 denotes an evaporator provided in the room 2,
For example, a compressor for compressing the refrigerant from the evaporator 3 and a compressor 5
A condenser for condensing the high-temperature and high-pressure refrigerant from the condenser; 6 an expansion means for expanding the refrigerant from the condenser 5 into a low-temperature and low-pressure refrigerant to supply the refrigerant to the evaporator 3; , A temperature sensor 8 for detecting the temperature in the chamber 2, a reference numeral 9 including a microcomputer 9a to which the outputs of the temperature sensors 7 and 8 are added and having a relative humidity calculation function, and controlling a refrigeration cycle. The arithmetic and control unit, 10 is a blower fan of the evaporator 3, 11 is a blower fan of the condenser 5, and N is a blower intensity of the blower fan 10. Next, the operation will be described. In FIG. 4, the compressor 4, the condenser 5, the expansion means 6
And the evaporator 3 constitute a refrigeration cycle. The operation of the refrigeration cycle will be described with reference to FIG. Assuming that the room temperature is ta and the room air is enthalpy ia, first, a relative humidity curve 通 る passing through a point (d) where a line (c) of the temperature ta intersects with an isoenthalpy line (b) from the point of the enthalpy ia. The relative humidity is determined. Then, the relationship between the room temperature and the relative humidity using the respective enthalpy lines as parameters is input to the microcomputer 9a, and the relative humidity ψ is calculated from the obtained enthalpy ia of the room air and the room temperature ta. As described above, the indoor relative humidity ψ is determined based on the two temperature sensors 7 and 8 that detect the evaporator temperature and the indoor temperature, and the detection values of these two temperature sensors 7 and 8 and the blowing intensity N. The estimated value of the relative humidity in the room can be obtained by using the relatively simple microcomputer 9a that performs the arithmetic processing as described above, whereby the expensive humidity sensor conventionally used becomes unnecessary, and the control system can be implemented. It can be constructed at low cost. [Problem to be Solved by the Invention] Since the conventional humidity controller of the air conditioner is configured as described above, the temperature and humidity (enthalpy) of the outlet air of the evaporator 3 can be easily estimated. When a heater is provided on the downstream side of the blower of the evaporator 3, the heater has a control system different from that of the evaporator. There was a problem that an estimation algorithm had to be provided. The present invention has been made in order to solve the above-described problems. In one refrigeration cycle, heating, cooling, dehumidification, and the like can be freely performed, and the temperature and humidity of the temperature- and humidity-controlled air can be controlled. All estimations can be performed using data from a single refrigeration cycle, which simplifies the estimation algorithm, and provides a wide-range, highly responsive temperature and humidity control system capable of controlling temperature and humidity. The purpose is to obtain. [Means for Solving the Problems] The constant temperature and humidity apparatus according to the present invention includes two indoor heat exchangers arranged in a duct so as to be in series with the flow of wind, and a high pressure liquid from the aggregator. A high-low pressure heat exchange accumulator that exchanges heat between the refrigerant and the low-pressure wet refrigerant from the evaporator and has an outlet connected to the suction port of the compressor, a high-pressure gas pipe, a high-pressure liquid pipe, a high-pressure subcool pipe, and a low-pressure wet pipe. , An outdoor heat exchanger, and a high-pressure gas pipe and a low-pressure wet pipe connected to each end of the two indoor heat exchangers and one end of the outdoor heat exchanger via a solenoid valve, respectively, so that flow paths can be selected. And one end of an electronic expansion valve is connected to the other end of each indoor and outdoor heat exchanger, and the other end of the electronic expansion valve can select a high-pressure liquid pipe and a high-pressure subcool pipe via an electromagnetic valve. Connect to the two rooms based on the temperature and humidity set by the user. Determine the operation mode of the internal heat exchanger, evaporator capacity corresponding to the amount of dehumidification,
Calculation means for estimating the condenser capacity corresponding to the heating amount, the target evaporator pipe surface temperature to be targeted, the low pressure / high pressure of the refrigeration cycle corresponding to the condenser pipe surface temperature, the low pressure is based on the humidity target value, and the high pressure is based on the temperature. Control means for separately controlling the high pressure and the low pressure from the target value is provided. [Operation] In the constant temperature and humidity apparatus according to the present invention, since the refrigerant flowing through each pipe is fixed regardless of the operation mode, one end of only the outdoor or indoor heat exchanger is connected to the high-pressure gas pipe when performing the heating operation. And the other end is opened to a high-pressure liquid pipe. The electronic expansion valve at that time is fully open. When performing the cooling operation, open one end of the outdoor or indoor heat exchanger only to the low-pressure wet pipe, open the other end to the high-pressure subcool pipe, and use an electronic expansion valve to set the heat exchanger outlet to an appropriate level. The opening degree is controlled so as to be a refrigerant. In this way, the two indoor heat exchangers are separately operated for heating in accordance with the target temperature and humidity,
By switching between cooling operation and stop, air heating,
Cooling and dehumidification can be performed. In such a device, the amount of dehumidification in the evaporator and the amount of heating in the aggregator are calculated and estimated from the temperature and humidity target values set by the user and the refrigerant characteristic values of the refrigeration cycle, and the high and low pressures of the refrigeration cycle are calculated. By controlling freely, temperature and humidity can be controlled with high accuracy in one refrigeration cycle. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 4 is a compressor, 12 is an outdoor heat exchanger, 13
Are the indoor heat exchangers No. 1 and 14, the indoor heat exchangers No. 2 and 15 are the ducts in which the indoor heat exchangers 13 and 14 are arranged in series, and 16 is the downstream side of the indoor heat exchanger No. 2. Humidifier, 17 is a blower fan for duct 15, 18 is an outdoor fan for outdoor heat exchanger 12, 19 is a high-pressure subcool pipe, 20 is a high-pressure liquid pipe, 21 is a low-pressure wet pipe, 22 is a high-pressure gas pipe, 23 is a high and low pressure heat exchange accumulator, 24 is one end of each heat exchanger 13, 14, 12, 25 is the other end, 26 is an electronic expansion valve connected to the other end 25 of each heat exchanger, 27 is each heat exchange A solenoid valve connected between the flow path between the vessel end 24 and the high-pressure gas pipe 22;
Is a solenoid valve connected between the flow path between the heat exchanger one end 24 and the low-pressure wet pipe 21; 29 is a flow path between the electronic expansion valve 26 and the high-pressure liquid pipe 20 connected to the other end 25 of the heat exchanger. An electromagnetic valve 30 interposed therebetween is an electromagnetic valve interposed between the flow paths of the electronic expansion valve 26 and the high-pressure subcool pipe 19. As described above, each of the indoor heat exchangers 13 and 14 and the four pipes 19 to 2
2, the outdoor heat exchanger 12 and four pipes 19-22
Has exactly the same configuration. 31 and 32 are temperature sensors attached to the discharge and suction ports of the compressor 4, respectively, and 33 and 34 are indoor heat exchangers No. 1 (13).
Temperature sensors provided at one end 24 and the other end 25 of the indoor heat exchanger 35, 36 are temperature sensors provided at one end 24 and the other end 25 of the indoor heat exchanger No. 2 (14), and 37 and 38 are indoor heat exchangers. Saturation temperature detection temperature sensors provided at 13, 14; 39, 40 are inlets of duct 15, temperature sensors provided at outlets; 41, 42 are inlets of duct 15,
This is a temperature sensor provided at the outlet. Reference numeral 43 denotes a setting unit for the user to set the temperature / humidity target values, and reference numeral 44 denotes a control unit for controlling the low pressure and the high pressure of the refrigeration cycle, and the temperature / humidity target values and the temperature sensors 31, 32 to 40,
It includes a microcomputer 44a as a calculating means for estimating and calculating the amount of dehumidification of the evaporator and the amount of heating of the condenser from the refrigerant characteristic values based on the outputs of the humidity sensors 41 and 42. Next, the operation will be described. The method of estimating the air temperature and humidity on the load side and determining the low pressure and high pressure of the refrigeration cycle will be described using mathematical expressions. Indoor heat exchanger No.1 (13) is an evaporator, indoor heat exchanger No.2
Considering the case where (14) operates as a condenser, indoor heat exchanger No. 1 (13) is dehumidifier and indoor heat exchanger No. 2 (1
4) is acting as a heater. At this time,
Assuming that the enthalpy on the refrigerant side of the indoor heat exchanger No. 1 (13) is hei, heo and the flow rate of the refrigerant flowing through the indoor heat exchanger No. 1 (13) is Ge, the cooling capacity Qe is Qe = Ge ( heo-hei) ... (1) Also, assuming that the air-side inlet and outlet enthalpies of the indoor heat exchanger No. 1 (13) are ha ₁ and ha ₂ and the air volume in the duct is Ga, the cooling capacity Qe is Qe = Ga (ha ₁ ha ₂₎ (2) also to be expressed, Messrs. (1), it is obtained outlet air enthalpy ha ₂ (2) from the indoor heat exchanger No.1 (13). Also, the heat transfer area of the indoor heat exchanger No. 1 (13) is A ₁ , the heat transfer rate between the refrigerant and air is K ₁ , and the refrigerant side and air side inlets of the indoor heat exchanger No. 1 (13) · the logarithmic mean temperature difference calculated from the outlet temperature When Delta] t _1, the cooling capacity Qe because the _{Qe = a 1 K 1 Δt 1} ...... (3), the outlet air of the indoor heat exchanger No.1 (13) Temperature ta
You can ask for ₂ . The same applies to the indoor heat exchanger No. 2 (14), and the refrigerant side inlet / outlet enthalpy hci / hco, the air side inlet / outlet enthalpy are ha ₂ and ha ₃ , and the indoor heat exchanger No. 2 (14) is used. The refrigerant flow rate is Gc, and the heat transfer area of indoor heat exchanger No.2 (14) is
A ₂ , K ₂ is the heat transfer rate between the refrigerant and air, Δt ₂ is the logarithmic average temperature difference obtained from the inlet and outlet temperatures of the refrigerant and air, and Qc is the heating capacity of the indoor heat exchanger No. 2 (14). Then, duct 15
Since the air volume of the inner is a Ga Qc = Gc (hci-ha 2) ...... (4) Qc = Ga (ha 3 -ha 2) ...... (5) Qc = A 2 K 2 Δ 2 ...... (6) The following three equations hold, and from these, the indoor heat exchanger No. 2 (14)
The air-side outlet enthalpy ha ₃ and the air-side outlet temperature ta ₃ are obtained. Then, the indoor heat exchanger from the psychrometric chart No.2 (14) relative humidity [psi ₃ at the outlet can also be determined. The above is described based on the Mollier diagram showing the behavior on the refrigerant side in FIG. 2 and the psychrometric diagram showing the behavior on the air side in FIG. First, in FIG. 3, the temperature, enthalpy, relative humidity, and absolute humidity of the air at the inlet α of the indoor heat exchanger No. 1 (13) are represented by t _α , h _α , ψ _α , x _α , respectively. This cooled by the indoor heat exchanger No.1 pipe surface temperature is t _f (13) ·
By being dehumidified, it follows the trajectory and becomes β. Assuming that the temperature, enthalpy, relative humidity, and absolute humidity of the air of _β are t _β , h _β , ψ _β , and x _β , respectively, t _f <t _β <
a t _α, h β in _{<h α, 100 ≧ ψ β} > ψ β, consisting of _x β ≦ x α relationship. Next, since it is heated by the indoor heat exchanger No. 2 (14), it follows the trajectory and enters the state of γ. Temperature of gamma, enthalpy, relative humidity, absolute humidity _{t γ, h γ, ψ γ} , a _{x γ, t γ> t β} , the _{h γ> h β, ψ γ} <ψ β, x γ = x β In a relationship. Looking at the behavior of the refrigerant at this time in a Mollier diagram shown in FIG. 2, the high-temperature and high-pressure refrigerant (a) that has exited the compressor 4 is:
After being cooled (heating the surrounding air) by the indoor heat exchanger No. 2 (14) functioning as a condenser (b) and further cooled by the high / low pressure heat exchange accumulator 23 (c), the electronic expansion valve 26
(D), heated (cooling and dehumidifying the surrounding air) in the indoor heat exchanger No. 1 (13) working as an evaporator (e), and after liquid separation in the high / low pressure heat exchange accumulator 23, It is slightly heated (f) and sucked into the compressor 4 again. With the above operation, the humidity and temperature of the air are adjusted.If the temperature of each part of the refrigeration cycle is monitored, the temperature and humidity in the duct 15 are brought closer to the temperature and humidity set by the setting unit 43. Is the pressure (low pressure) of the refrigerant flowing through the evaporator
And what value the pressure (high pressure) of the refrigerant flowing through the condenser should be set in each of the expressions (1) to (6) given above.
It can be more easily analogized. That is, since the set temperature and humidity are nothing but t _γ and ψ _γ , x
_γ and h _γ are immediately known. Here beta is on .alpha.f, and so must be _{x β} = x γ in beta, the state amount in the beta is obtained as the intersection. Therefore, by monitoring the temperature and humidity t _α and ψ _α of the inlet state α, it is possible to calculate the required dehumidification amount, the change amount on the air side enthalpy, etc., and determine the target high pressure and low pressure. become. By adjusting the frequency of the compressor 4, the operation mode of the outdoor heat exchanger 12, the rotation speed of the outdoor fan 18, and the like by the control unit 44, the high pressure and the low pressure can be made closer to the target high pressure and the target low pressure, respectively. Further, the humidifier 16 can appropriately perform humidification. In the above embodiment, four solenoid valves 27 to 30 are used for each of the heat exchangers 13, 14, and 12, but a three-way switching valve or a four-way valve may be used. [Effects of the Invention] As described above, according to the present invention, a compressor, a high / low pressure heat exchange accumulator, a high pressure gas pipe, a high pressure liquid pipe, a high pressure subcool pipe, and a low pressure wet pipe are arranged, The same flow path can be selected for the heat exchanger regardless of whether it is indoor or outdoor, and a high-pressure gas pipe and a low-pressure wet pipe can be selected at one end of each heat exchanger.
Two indoor heat exchangers are connected in series to the flow of wind in one duct using a refrigeration cycle that can select a high-pressure liquid pipe and a high-pressure subcool pipe via the electronic expansion valve at the other end. The operation mode of each heat exchanger, the amount of dehumidification in the evaporator and the amount of heating in the condenser, and the refrigeration cycle based on it should be set based on the set temperature / humidity and the temperature of each part of the refrigeration cycle. Since the refrigeration cycle is controlled by estimating the high and low pressures, both high and low pressures can be controlled freely in one refrigeration cycle, which enables temperature and humidity control to be performed in a wide range with high accuracy. In addition, there is an effect that an inexpensive and highly responsive device can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a constant temperature and humidity apparatus according to an embodiment of the present invention, FIG. 2 is a characteristic diagram of a refrigerant on a Mollier diagram, FIG.
Fig. 4 is an air line diagram showing changes in the state of air when the two heat exchangers in the duct are evaporators and condensers from the upstream side, respectively. Fig. 4 is the humidity control of a conventional air conditioner. FIG. 5 is a block diagram showing the apparatus, and FIG. 5 is a characteristic diagram showing a relative humidity estimation method in a conventional air conditioner. 4 is a compressor, 12 is an outdoor heat exchanger, 13 and 14 are indoor heat exchangers, 15 is a duct, 19 is a high-pressure subcooled pipe, 20 is a high-pressure liquid pipe, 21 is a low-pressure wet pipe, 22 is a high-pressure gas pipe, 23 Are high and low pressure heat exchange accumulators, 24 and 25 are one end and the other end of each heat exchanger, 26 is an electronic expansion valve, 27 to 30 are solenoid valves, 31 to 40 are temperature sensors, 41 and 42 are humidity sensors, 44 Is a control unit, and 44a is a microcomputer. In the drawings, the same reference numerals indicate the same or corresponding parts.

   ────────────────────────────────────────────────── ─── Continuation of front page       (56) References JP-A-2-52964 (JP, A)                 JP-A-2-68467 (JP, A)                 JP-A-62-14273 (JP, A)                 JP-A-58-184476 (JP, A)                 JP-A-61-289246 (JP, A)                 Showa 55-67954 (JP, U)                 Tokiko Hei 1-46772 (JP, B2)

Claims (1)

(57) [Claims 1] An indoor heat exchanger, an outdoor heat exchanger, a compressor, and a condenser arranged in series in a ventilation duct with respect to the flow of wind. The heat exchange between the high-pressure liquid refrigerant and the low-pressure wet refrigerant from the evaporator is performed, and one end is connected to each of the high-low pressure heat exchange accumulator whose outlet is connected to the suction port of the compressor, and the high-low pressure heat exchange accumulator. A high-pressure subcooled pipe, a high-pressure liquid pipe, a low-pressure wet pipe, a high-pressure gas pipe having one end connected to the discharge side of the compressor, and one end of each of the two indoor heat exchangers and the outdoor heat exchanger connected to the low-pressure pipe. An electromagnetic valve for selectively connecting to a wet pipe or a high-pressure gas pipe; an electronic expansion valve having one end connected to each of the other ends of the two indoor heat exchangers and the outdoor heat exchanger; Connect the other end of the valve to the high pressure subcool Or a solenoid valve selectively connected to a high-pressure liquid pipe, the two indoor heat exchangers, the temperature sensors provided at the one end and the other end thereof, and the inlet side and the outlet side of the air duct, respectively, Humidity sensors provided on the inlet side and the outlet side of the air duct, a setting unit for setting a temperature target value and a humidity target value, and the detected values of the temperature sensors and the humidity sensors and predetermined refrigerant characteristics of the refrigeration cycle. A calculating means for estimating a high pressure and a low pressure of the refrigerant of the refrigeration cycle based on the low pressure and the high pressure estimated by the calculating means, the low pressure is based on the humidity target value, and the high pressure is a low pressure based on the temperature target value. A constant-temperature and constant-humidity device comprising: a control unit that separately controls a refrigerant and a high-pressure refrigerant.