阅读说明：本技术 一种低环温制冷用风冷冷水机组及控制方法 (Air-cooled water chilling unit for low-ring-temperature refrigeration and control method ) 是由 谷涛 李伟 鲁智高 于 2021-03-04 设计创作，主要内容包括：一种低环温制冷用风冷冷水机组及控制方法,包括通过管道依次连接的压缩机、风冷换热装置、膨胀阀、水侧换热器、压缩机形成的闭合回路机构,所述风冷换热装置包括第一换热器、以及与第一换热器并联的一个或多个并联换热器,所述并联换热器入口处设有第一电磁阀,出口处连接有第二电磁阀,所述第二电磁阀出口与水侧换热器的入口连接。本发明避免了并联换热器停止运行后制冷剂留存在其中,不能充分利用,从而保证了制冷剂全部参与运行,保证了制冷效果。(An air-cooled water chilling unit for low-ring-temperature refrigeration and a control method thereof comprise a closed loop mechanism formed by a compressor, an air-cooled heat exchange device, an expansion valve, a water-side heat exchanger and the compressor which are sequentially connected through pipelines, wherein the air-cooled heat exchange device comprises a first heat exchanger and one or more parallel heat exchangers connected with the first heat exchanger in parallel, a first electromagnetic valve is arranged at an inlet of each parallel heat exchanger, a second electromagnetic valve is connected at an outlet of each parallel heat exchanger, and an outlet of each second electromagnetic valve is connected with an inlet of the water-side heat exchanger. The invention avoids the refrigerant remaining in the parallel heat exchanger after stopping running and being incapable of being fully utilized, thereby ensuring the refrigerant to completely participate in running and ensuring the refrigeration effect.)

1. The utility model provides a low ring temperature is air-cooled cooling water set for refrigeration, includes the closed loop mechanism that compressor, air-cooled heat transfer device, expansion valve, water side heat exchanger, the compressor that connects gradually through the pipeline formed, its characterized in that: the air-cooled heat exchange device comprises a first heat exchanger and one or more parallel heat exchangers connected with the first heat exchanger in parallel, a first electromagnetic valve is arranged at an inlet of each parallel heat exchanger, a second electromagnetic valve is connected at an outlet of each parallel heat exchanger, and an outlet of each second electromagnetic valve is connected with an inlet of the water-side heat exchanger.

2. The air-cooled chiller unit for low loop temperature refrigeration as claimed in claim 1, wherein: and a gas-liquid separator is arranged between the outlet of the water side heat exchanger and the inlet of the compressor.

3. The air-cooled chiller unit for low loop temperature refrigeration as claimed in claim 1, wherein: the outlet of the parallel heat exchanger is also connected with a one-way valve, the inlet of the one-way valve is connected with the outlet of the parallel heat exchanger, the outlet of the one-way valve is connected with the inlet of the expansion valve, and the first electromagnetic valve, the parallel heat exchanger and the one-way valve are connected in series and then are connected with the first heat exchanger in parallel.

4. The air-cooled chiller unit for low loop temperature refrigeration as claimed in claim 1, wherein: the air-cooled heat exchange device also comprises a fan arranged at the first heat exchanger and the parallel heat exchanger.

5. The air-cooled chiller unit for low loop temperature refrigeration as claimed in claim 1, wherein: and a pressure sensor is arranged at an outlet of the first heat exchanger and is electrically connected with the unit controller.

6. A control method of an air-cooled chiller for low loop temperature refrigeration using the unit of any one of claims 1 to 5, comprising:

step 1: when the condensation pressure value detected by a pressure sensor at the outlet of the first heat exchanger is smaller than a preset value, closing the first electromagnetic valve and opening the second electromagnetic valve;

step 2: and after the continuous operation is carried out for the preset time, closing the second electromagnetic valve.

7. The control method of the air-cooled chiller for low-loop temperature refrigeration as set forth in claim 6, wherein: the step 2 is followed by:

controlling the running number of the parallel heat exchangers: when the number of the parallel heat exchangers is multiple, the number of the parallel heat exchangers in operation is controlled according to the condensation pressure value detected by the pressure sensor at the outlet of the first heat exchanger, when the condensation pressure value is increased, the number of the parallel heat exchangers in operation is increased, and when the condensation pressure value is reduced, the number of the parallel heat exchangers in operation is reduced.

Technical Field

The invention relates to the field of refrigeration systems, in particular to an air-cooled water chilling unit for low-loop-temperature refrigeration and a control method.

Background

The general refrigeration operation environment temperature range of the air conditioner is above 15 ℃, however, in some technological special application occasions, the air conditioning unit needs to perform refrigeration operation at the environment temperature of less than 15 ℃, and the unit needs to perform refrigeration operation all the year round. At the lower environmental temperature, the condensing pressure in the condenser is too low, the pressure before the expansion valve is too low, the pressure difference before and after the expansion valve is too small, the capacity of the expansion valve is reduced, the liquid supply capacity is insufficient, the evaporator lacks liquid, and the refrigerating capacity of the system is greatly reduced, so that the refrigerating system is in failure. At present, when an air-cooled water chilling unit for low-ring-temperature refrigeration operates at low ambient temperature, a double-speed or multi-gear speed-regulation condensing fan is generally adopted, when the ambient temperature is lower, the air speed is reduced, the heat exchange quantity of an air-cooled heat exchanger is reduced, the condensing pressure is increased to be higher than a certain pressure to ensure the operation of a system, but the rotating speed of a motor cannot be too low, the speed is limited to a certain degree, and therefore the phenomenon of lower condensing pressure can still be generated, and the unreliable operation of the system is caused.

Disclosure of Invention

The invention provides an air-cooled water chilling unit for low-ring-temperature refrigeration and a control method thereof, aiming at the problems that when the existing air-cooled water chilling unit for low-ring-temperature refrigeration runs at a lower environment temperature, the condensing pressure is lower, and the high-low pressure difference of a compressor is too small.

The technical scheme of the invention is as follows:

the utility model provides a low ring temperature is air-cooled cooling water set for refrigeration, includes the closed loop mechanism that compressor, air-cooled heat transfer device, expansion valve, water side heat exchanger, the compressor that connects gradually through the pipeline formed, air-cooled heat transfer device includes first heat exchanger and one or more parallelly connected heat exchanger parallelly connected with first heat exchanger, parallelly connected heat exchanger entrance is equipped with first solenoid valve, and the exit is connected with the second solenoid valve, the second solenoid valve export is connected with the entry linkage of water side heat exchanger.

And a gas-liquid separator is arranged between the outlet of the water side heat exchanger and the inlet of the compressor.

The outlet of the parallel heat exchanger is also connected with a one-way valve, the inlet of the one-way valve is connected with the outlet of the parallel heat exchanger, the outlet of the one-way valve is connected with the inlet of the expansion valve, and the first electromagnetic valve, the parallel heat exchanger and the one-way valve are connected in series and then are connected with the first heat exchanger in parallel.

The air-cooled heat exchange device also comprises a fan arranged at the first heat exchanger and the parallel heat exchanger.

And a pressure sensor is arranged at an outlet of the first heat exchanger and is electrically connected with the unit controller.

A control method of an air-cooled water chilling unit for low-loop-temperature refrigeration comprises the following steps:

step 1: when the condensation pressure value detected by a pressure sensor at the outlet of the first heat exchanger is smaller than a preset value, closing the first electromagnetic valve and opening the second electromagnetic valve;

step 2: and after the continuous operation is carried out for the preset time, closing the second electromagnetic valve.

The step 2 is followed by: controlling the running number of the parallel heat exchangers: when the number of the parallel heat exchangers is multiple, the number of the parallel heat exchangers in operation is controlled according to the condensation pressure value detected by the pressure sensor at the outlet of the first heat exchanger, when the condensation pressure value is increased, the number of the parallel heat exchangers in operation is increased, and when the condensation pressure value is reduced, the number of the parallel heat exchangers in operation is reduced.

Compared with the prior art, the air-cooled water chilling unit for low-ring-temperature refrigeration and the control method thereof work in parallel through the plurality of heat exchangers, when the ambient temperature is lower, the condensation pressure is still lower after measures of reducing the rotating speed of a fan of the air-cooled heat exchange device and slowing down the heat emission speed, and when the condensation pressure value is lower than a preset value, the number of the heat exchangers in operation is reduced and the heat exchange area of the heat exchangers is reduced by closing the first electromagnetic valve at the inlet of the parallel radiator, so that the condensation pressure is improved, and a refrigeration system can normally operate; the second step is through opening the second solenoid valve, the intercommunication of parallel heat exchanger export and water side heat exchanger entry after the shut down has been realized, the parallel heat exchanger of shut down this moment, water side heat exchanger is linked together with the compressor pipeline, the refrigerant in the heat exchanger of shut down is sucked to the water side heat exchanger through the compression suction effect of compressor, make the refrigerant of reserving in the parallel heat exchanger of shut down can enter into refrigerant circulation system again and move, refrigerant is reserved wherein after having avoided parallel heat exchanger shut down, can not make full use of, thereby guaranteed that the refrigerant is all participated in the operation, guaranteed the refrigeration effect.

Drawings

FIG. 1 is a schematic view of the operating condition of the parallel heat exchanger of the present invention.

Fig. 2 is a schematic view of the parallel heat exchanger of the present invention in a shutdown state.

Wherein, 1 is a compressor; 2, an air cooling heat exchange device; 3 is a first heat exchanger; 4 is a parallel heat exchanger; 5 is an expansion valve; 6 is a water side heat exchanger; 7 is a gas-liquid separator; 8 is a first solenoid valve; 9 is a one-way valve; 10 is a second solenoid valve; 11 is a fan; 12 is the water inlet of the water side heat exchanger; and 13 is a water outlet of the water side heat exchanger.

Detailed Description

The present invention is not limited by the following examples, and specific embodiments may be determined according to the technical solutions and practical situations of the present invention.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Therefore, the following detailed description of the embodiments of the present invention, provided in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention, on the basis of which all other embodiments, obtained by a person of ordinary skill in the art without inventive faculty, fall within the scope of the invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

As shown in fig. 1-2, the invention provides an air-cooled water chiller for low-loop temperature refrigeration, which comprises a compressor 1, an air-cooled heat exchanger 2, an expansion valve 5 and a water-side heat exchanger 6 which are sequentially connected through pipelines, wherein an outlet of the compressor 1 is connected with an inlet of the air-cooled heat exchanger 2, an outlet of the air-cooled heat exchanger 2 is connected with an inlet of the expansion valve 5, an outlet of the expansion valve 5 is connected with an inlet of the water-side heat exchanger 6, an outlet of the water-side heat exchanger 6 is connected with an inlet of the compressor 1, the air-cooled heat exchanger 2, the expansion valve 5, the water-side heat exchanger 6 and the compressor 1 form a closed loop refrigeration device, the air-cooled heat exchanger 2 comprises a first heat exchanger 3 and a parallel heat exchanger 4 which is connected with the first heat exchanger in parallel, one or more parallel heat exchangers 4 can be arranged and are all connected with the first heat, the inlet of the first electromagnetic valve 8 is connected with the outlet of the compressor 1, and the outlet of the first electromagnetic valve 8 is connected with the inlet of the parallel heat exchanger 4. When the first electromagnetic valve 8 is opened, the refrigerant can flow into the parallel heat exchange unit 4 from the first electromagnetic valve 8, and when the first electromagnetic valve 8 is closed, the refrigerant cannot flow into the parallel heat exchange unit 4. The outlet of the parallel heat exchanger 4 is connected with a one-way valve 9, the inlet of the one-way valve 9 is connected with the outlet of the parallel heat exchanger 4, the outlet of the one-way valve 9 is connected with the expansion valve 5, and the one-way valve 9 enables the refrigerant to flow from the inlet to the outlet of the one-way valve 9 only and not to flow reversely. The outlet of the parallel heat exchanger 4 is also connected with a second electromagnetic valve 10, and the outlet of the second electromagnetic valve 10 is connected with the inlet of the water-side heat exchanger 6. When the second electromagnetic valve 10 is opened, a communicated pipeline passage is formed among the parallel heat exchanger 4, the water side heat exchanger 6 and the compressor 1, the refrigerant in the parallel heat exchanger 4 is sucked into the water side heat exchanger 6 through the compression and suction effects of the compressor, and thus the refrigerant remained in the parallel heat exchanger 4 can reenter the circulation operation of the refrigerant. The first electromagnetic valve 8, the parallel heat exchanger 4 and the check valve 9 form a group of series passages, the formed series passages are connected with the first heat exchanger 3 in parallel, a plurality of groups of series passages similar to the series passages formed by the first electromagnetic valve 8, the parallel heat exchanger 4 and the check valve 9 can be arranged, and the plurality of series passages are connected with the first heat exchanger 3 in parallel. These connections are all connected by piping. The water side heat exchanger 6 is provided with a water side heat exchanger water inlet 12 and a water side heat exchanger water outlet 13, heat exchange is carried out between the refrigerant and circulating water of the water side heat exchanger in the water side heat exchanger 6 to obtain cold circulating water, and the cold circulating water is continuously conveyed to a position needing refrigeration through a pipeline.

Further, the air-cooled heat exchange device 2 further comprises a fan 11 located at the first radiator 3 and the parallel heat exchanger 4, and the fan 11 is used for accelerating air convection and improving the heat dissipation speed of the first heat exchanger 3 and the parallel heat exchanger 4.

Further, a pressure sensor is arranged at the outlet of the first heat exchanger 3 and used for measuring condensation pressure, and the pressure sensor is electrically connected with a controller of the air cooling water chilling unit.

Further, a gas-liquid separator 7 is arranged between the outlet of the water-side heat exchanger 6 and the inlet of the compressor 1, the inlet of the gas-liquid separator 7 is connected with the outlet of the water-side heat exchanger 6 through a pipeline, and the outlet of the gas-liquid separator 7 is connected with the inlet of the compressor 1 through a pipeline. The gas-liquid separator 7 recovers and stores the liquid lubricating oil, the refrigerant, the moisture and the like from the water side heat exchanger 6, thereby avoiding the liquid impact caused by the entering of the liquid lubricating oil, the refrigerant, the moisture and the like into the compressor 1.

When the condensing pressure value detected by a pressure sensor at the outlet of a first heat exchanger 3 is higher than a preset value, a second electromagnetic valve 10 is in a closed state, a first electromagnetic valve 8 is in an open state, and the first heat exchanger 3 and a parallel heat exchanger 4 run normally when the air-cooled water chiller works normally. At this time, the refrigerant comes out of the compressor 1 and enters the first heat exchanger 3 and the parallel heat exchanger 4 at the same time, then comes out of the first heat exchanger 3 and the parallel heat exchanger 4 respectively and enters the water side heat exchanger 6 through the expansion valve 5, and comes out of the water side heat exchanger 6 and returns to the compressor 1 again through the gas-liquid separator 7 to form a closed loop, as shown in fig. 1.

When the condensation pressure value detected by the pressure sensor at the outlet of the first heat exchanger 3 is less than the preset value:

step 1: closing the first electromagnetic valve 8, opening the second electromagnetic valve 10, stopping the refrigerant from entering the parallel heat exchanger 4, stopping the operation of the parallel heat exchanger 4, as shown in fig. 2, at this time, the refrigerant only enters the first heat exchanger 3 after coming out from the compressor 1, enters the expansion valve 5 after coming out from the first heat exchanger 3, enters the water side heat exchanger 6 after being subjected to pressure regulation and throttling by the expansion valve 5, and returns to the compressor 1 again through the gas-liquid separator 7 after heat transfer, so as to form a closed loop. After the second electromagnetic valve 10 is opened, the parallel heat exchanger 4, the water side heat exchanger 6 and the compressor 1 which are stopped to operate are communicated through a pipeline, and the refrigerant, the hydraulic lubricating oil and the like which are retained in the parallel heat exchanger 4 which is stopped to operate are sucked into the water side heat exchanger 6 through the continuous compression and suction action of the compressor 1, and continuously participate in the circulation operation of the refrigerant.

Step 2: after the operation for a preset time, the second solenoid valve 10 is closed. Through the suction effect of the compressor 1, all the refrigerant remained in the parallel heat exchanger 4 is sucked into the water side heat exchanger 6, so that the refrigerant remained in the parallel heat exchanger 4 can continuously enter the refrigeration cycle process, the problem that the refrigerant is continuously reduced due to the stop work of the parallel heat exchanger 4, the refrigeration effect is influenced is avoided, and the refrigerant can completely participate in the operation is ensured.

Further, step 2 may be followed by a step of controlling the number of parallel heat exchangers 4 in operation, wherein the number of parallel heat exchangers 4 in operation is controlled according to the magnitude of the condensation pressure value detected by the pressure sensor at the outlet of the first heat exchanger 3. When the detected condensation pressure value is reduced, the running number of the parallel heat exchangers 4 is reduced, the heat exchange area is reduced, and the condensation pressure is further improved; when the detected condensation pressure value is increased, the running number of the parallel heat exchangers 4 is increased, and the heat exchange area is increased.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

The technical features of the embodiments described above can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, however, as long as there is no contradiction between the combinations of the technical features, the combinations of the technical features should be considered as being within the scope described in the present specification, and when the combinations of the technical features are contradictory or cannot be realized, the combinations of the technical features should be considered as not being present, and the combinations of the technical features are not within the scope of the claims. Also, it will be apparent to those skilled in the art that various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the spirit of the principles of the invention.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various changes and modifications can be made without departing from the overall concept of the present invention, and these should also be considered as the protection scope of the present invention.