CN201772571U - A multi-connected indoor unit air side bypass capacity control device - Google Patents

Abstract

The utility model relates to a capacity control device with an air side bypass for multi-line indoor unit. The capacity control device is characterized by the inclusion of a housing of an indoor unit, wherein an air inlet is formed at the end part on one side of the housing, a blower is arranged in the housing and corresponds to the air inlet, and an outlet of the blower and a ventilation opening of a wind shield are formed correspondingly; indoor return air is blown into a heat exchanger and a bypass air port respectively after being blown into the indoor unit through the ventilation opening; an electronic expansion valve is arranged on one side of the heat exchanger, and a water condensation plate is arranged at the bottom on the other side; an air side electric bypass air valve is arranged at the bypass air port; and an air supply outlet is also formed on the housing. The capacity control device has simple control performance, and the operation stability of the system is better. The utility model can be extensively applied to various multi-line systems in the heating ventilation and air conditioning field.

Description

A multi-connected indoor unit air side bypass capacity control device

technical field

The utility model relates to a control device in the field of heating, ventilating and air conditioning, in particular to a wind side bypass capacity control device of a multi-connected indoor unit.

Background technique

The multi-connected system adopts variable capacity adjustment to match the system load change, and gradually shows better performance in terms of system energy saving. The independent control and individual adjustment of each indoor unit improves indoor comfort. In recent years, it is causing more and more more and more attention.

In the VRF (VRF, Variable Refrigerant Flow, variable refrigerant flow) system, due to the actual operation of each indoor unit, the load rate changes differently, and the method of controlling the constant outlet superheat of the traditional unitary system cannot realize the cooling of each indoor unit. To distribute the cooling capacity among them, a new means of control and regulation must be added. There are many variable-capacity control methods commonly used in the existing indoor units, and the refrigerant side on-off control method and the superheat (cold) degree continuous adjustment method are mostly used. Under different control strategies, there are differences in the operating conditions of the system, which have different effects on indoor comfort and energy efficiency of the system. When the on-off control method of the expansion valve on the refrigerant side of the indoor unit is adopted, the control method is simple, but the indoor temperature fluctuates greatly, and the degree of comfort needs to be improved. In addition, the operating conditions of the outdoor unit are greatly affected by the on-off control of the indoor unit, and the system’s refrigeration cycle state may oscillate, reducing energy consumption performance; when the method of continuously adjusting the superheat (cold) degree on the refrigerant side is adopted, the system operation stability is relatively low. High, better energy efficiency. However, under partial load conditions under cooling conditions, the superheat of the compressor suction port may be high, which will affect the safety and energy efficiency of the system. The existing common solution is to add a liquid bypass auxiliary circuit to control the suction superheat of the compressor inlet, but the pipe network structure and control algorithm are relatively complicated.

Contents of the invention

In view of the above problems, the purpose of this utility model is to provide a multi-connected indoor unit air side bypass capacity control device with better operation stability, simple control and humidity control function.

In order to achieve the above purpose, the utility model adopts the following technical solutions: a multi-connected indoor unit air side bypass capacity control device, which is characterized in that it includes an indoor unit shell, and one end of the shell is provided with a The air inlet, inside the housing, is provided with a fan corresponding to the air inlet, and the outlet of the fan is arranged correspondingly to the vent of a windshield; the indoor return air is blown into the indoor unit through the vent After that, it is blown into a heat exchanger and a side vent respectively; an electronic expansion valve is set on one side of the heat exchanger, and a condensate pan is set on the bottom of the other side; a wind side electric side is set at the side vent. Ventilation valve; an air supply port is also arranged on the shell.

The fan is one of centrifugal, axial and cross-flow fans.

The continuous adjustment opening degree adopted by the electric bypass ventilation valve on the wind side is 0-100%.

The indoor unit is one of vertical, horizontal, column, wall-mounted and ceiling-mounted.

Because the utility model adopts the above technical scheme, it has the following advantages: 1. The utility model is equipped with a fan, a heat exchanger, a bypass vent, an electric bypass vent valve on the wind side and an electronic expansion valve in the indoor unit. The air volume is regulated independently by the user. Through the combined adjustment of the electric bypass ventilation valve on the air side of the indoor unit and the opening of the electronic expansion valve, the control of cooling capacity, outlet superheating degree, heating capacity, and outlet subcooling degree is realized. The control is simple and the system The running stability is better. 2. The utility model adopts the electronic expansion valve to control the flow rate of the refrigerant in the heat exchanger, and adopts the electric bypass ventilation valve on the wind side to control the air volume passing through the bypass vent, thereby changing the heat transfer coefficient of the wind side of the heat exchanger. , without affecting the indoor comfort, the stability of the system operation is improved, and the control is simple. 3. When the indoor unit of the utility model is in wet working condition, the air volume passing through the heat exchanger can be adjusted through the electric bypass ventilation valve on the wind side and the electronic expansion valve, which can change the ratio of sensible heat and latent heat absorbed by the heat exchanger. Therefore, the indoor Dehumidification control. The utility model can be widely used in various multi-connected systems in the field of HVAC.

Description of drawings

Fig. 1 is the overall structural representation of the utility model;

Fig. 2 is a schematic structural diagram of a horizontal indoor unit of the present invention;

Fig. 3 is a schematic structural diagram of a column-type indoor unit of the present invention;

Fig. 4 is a structural schematic diagram of the wall-mounted indoor unit of the present invention;

Fig. 5 is a structural schematic diagram of the ceiling-mounted indoor unit of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described in detail.

The utility model adopts the multi-connected indoor unit air side bypass capacity control principle: when the air volume passing through the heat exchanger in the indoor unit changes, the corresponding air side convective heat transfer coefficient and air side temperature distribution will change with the heat exchanger air volume. The result of the combined effect of the two can change the heat transfer capacity of the heat exchanger. The control method of the present invention contains two working conditions of refrigeration and heating, and its specific steps are as follows:

1) The indoor unit is provided with a fan, a heat exchanger, a side vent, an electric side vent valve on the wind side and an electronic expansion valve.

2) Under cooling conditions, the total air volume of the fan is independently controlled by the user through gear adjustment or frequency conversion, and the indoor unit is jointly adjusted by the electric bypass ventilation valve on the wind side and the opening of the electronic expansion valve to achieve the following cooling capacity and outlet Superheat control:

When the room load increases, the corresponding indoor temperature will rise. At this time, reduce the opening of the electric bypass ventilation valve on the wind side, so that the air volume passing through the bypass vent will decrease, and the corresponding air volume passing through the heat exchanger will increase. The convective heat transfer coefficient increases, and the cooling capacity increases; at the same time, the superheat degree of the heat exchanger outlet increases. At this time, the electronic expansion valve will also increase the opening degree, increase the refrigerant flow rate, and control the heat exchanger outlet superheat degree to be constant;

When the room load decreases, the corresponding indoor temperature will decrease. At this time, increase the opening of the electric bypass ventilation valve on the wind side, so that the air volume passing through the bypass vent will increase, and the corresponding air volume passing through the heat exchanger will decrease, and the air side will convect heat exchange. The coefficient becomes smaller, and the cooling capacity decreases; at the same time, the superheat degree of the heat exchanger outlet decreases. At this time, the electronic expansion valve will also reduce the opening degree, reduce the refrigerant flow rate, and control the superheat degree of the heat exchanger outlet to be constant.

3) Under heating conditions, the total air volume of the fan is independently controlled by the user through gear adjustment or frequency conversion, and the indoor unit can achieve the following heating capacity through the joint adjustment of the electric bypass ventilation valve on the wind side and the opening of the electronic expansion valve and outlet subcooling control:

When the room load increases, the corresponding indoor temperature will decrease. At this time, the opening of the electric bypass ventilation valve on the wind side will be reduced, so that the air volume passing through the bypass vent will decrease, and the corresponding air volume passing through the heat exchanger will increase. The thermal coefficient increases, and the heating capacity increases; at the same time, the subcooling degree of the heat exchanger outlet increases. At this time, the electronic expansion valve will also increase the opening degree, increase the refrigerant flow rate, and control the subcooling degree of the heat exchanger outlet to be constant;

When the room load decreases, the corresponding indoor temperature will rise. At this time, increase the opening of the electric bypass ventilation valve on the wind side, so that the air volume passing through the bypass vent will increase, and the corresponding air volume passing through the heat exchanger will decrease, and the wind side will convect heat exchange. The coefficient becomes smaller, and the heating capacity decreases; at the same time, the subcooling degree of the heat exchanger outlet decreases. At this time, the electronic expansion valve will also reduce the opening, reduce the refrigerant flow rate, and control the subcooling degree of the heat exchanger outlet to be constant.

As shown in FIG. 1 , the wind side bypass capacity control device of the multi-connected indoor unit of the present invention includes a casing 1 of the indoor unit, and an air inlet 2 is arranged at one end of the casing 1 . In the casing 1 , corresponding to the air inlet 2 , there is a fan 3 , and the outlet of the fan 3 is arranged correspondingly to the vent of a windshield 4 . Fan 3 blows the indoor return air into the indoor unit through a vent 5 on the windshield 4, and then divides into two paths and blows it into a heat exchanger 6 and a side vent 7 respectively. One side of the heat exchanger 6 is provided with an electronic expansion valve 8 for controlling the flow rate of the refrigerant in the heat exchanger 6, and a condensation pan 9 is provided at the bottom of the other side of the heat exchanger 6; The side electric bypass air valve 10 is used to control the air volume passing through the bypass air port 7 . After exchanging heat with the refrigerant in the heat exchanger 6, the indoor return air has a combined effect with the indoor return air flowing out through the bypass vent 7, and then is sent out by an air supply port 11 arranged on the shell 1.

In the above embodiments, the fan 3 can be a centrifugal fan, an axial fan or a cross-flow fan. The control method of the fan 3 can adopt multi-level adjustment or frequency conversion control.

In the above-mentioned embodiments, the opening degree of the electric bypass ventilation valve 10 on the wind side can be continuously adjusted from 0 to 100%.

To sum up, the multi-connected indoor unit air side bypass capacity control method and its device adopted in the utility model can reduce the complexity of the multi-connected system structure without affecting indoor comfort, and at the same time, the control is simple and reliable . In addition, when the indoor unit is operating in a wet condition, the electronic expansion valve 8 is used to adjust the air volume passing through the heat exchanger 6, which can change the ratio of sensible heat and latent heat absorbed by the heat exchanger 6 (humidity analysis coefficient), which can solve the existing problems. The problem that the online system cannot control humidity can realize indoor dehumidification control.

The above-mentioned embodiments are only used to illustrate the utility model, and the structure, size, setting position and shape of each component can be changed. For example, the indoor unit of the utility model can be vertical (as shown in Figure 1) , Horizontal type (as shown in Figure 2), column type (as shown in Figure 3), wall-mounted type (as shown in Figure 4) and ceiling type (as shown in Figure 5), etc., surface or concealed installation, etc. On the basis of the technical solution of the utility model, any improvement and equivalent transformation of individual components according to the principle of the utility model shall not be excluded from the protection scope of the utility model.

Claims (5)

1. multi-online indoor machine wind side bypass capacity control device, it is characterized in that: it comprises the shell of an indoor set, side end on the described shell is provided with an air inlet, in the described shell, the corresponding blower fan that is provided with described air inlet, the outlet of described blower fan is corresponding setting with the ventilating opening of a deep bead; Indoor return air is blown into respectively in a heat exchanger and one side ventilating opening after described ventilating opening is blown into described indoor set; One side of described heat exchanger is provided with an electric expansion valve, and the opposite side bottom is provided with one and coagulates water pond; Place, described bypass air port is provided with a wind side electric bypass air; Also be provided with an air outlet on the described shell.

2. a kind of multi-online indoor machine wind side bypass capacity control device as claimed in claim 1 is characterized in that: described blower fan adopts a kind of in centrifugal, axial-flow type and the cross flow blower.

3. a kind of multi-online indoor machine wind side bypass capacity control device as claimed in claim 1 or 2 is characterized in that: the continuous adjusting aperture that described wind side electric bypass air adopts is 0～100%.

4. a kind of multi-online indoor machine wind side bypass capacity control device as claimed in claim 1 or 2 is characterized in that: described indoor set adopts a kind of in vertical, horizontal, column, the wall-hanging and ceiling mounting type.

5. a kind of multi-online indoor machine wind side bypass capacity control device as claimed in claim 3 is characterized in that: described indoor set adopts a kind of in vertical, horizontal, column, the wall-hanging and ceiling mounting type.

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