CN114198929B - Strong cold room refrigerating unit and control method thereof - Google Patents

Abstract

The invention discloses a strong cooling room refrigerating unit and a control method thereof. The refrigerating unit comprises a compressor refrigerating device, a natural cooling device and a water path pipeline, wherein the water path pipeline penetrates through the evaporator and carries out heat exchange treatment on chilled water and a refrigerant in the evaporator; natural cooling pipe installs on the water route pipeline, and the water tower top is equipped with the ascending cooling chamber of opening and heat dissipation chamber, cooling chamber bottom section and heat dissipation chamber bottom section intercommunication, and natural cooling pipe is located the cooling intracavity, and spray set takes out the cooling water to cooling chamber top after, sprays the cooling water on natural cooling pipe, and the fan is all installed at heat dissipation chamber opening part. Through the cyclic utilization of the water tower to the chilled water, the consumption of the unit to water resources can be reduced, and the water utilization rate is improved. Through fan and spray set, with two kinds of cooling methods of forced air cooling and water-cooling combination, improve refrigeration efficiency, reduce energy consumption, reduce the fault rate of compressor.

Description

A forced cooling room refrigeration unit and its control method

technical field

The invention relates to the field of refrigeration equipment, in particular to a forced cooling room refrigeration unit and a control method thereof.

Background technique

At present, water-cooled screw chillers are generally used in the industry to provide cold water combined with indoor air supply equipment to cool down the forced cooling room. This kind of refrigeration unit consumes a lot of energy; and the evaporation temperature of the unit will be too high, exceeding the limit of the compressor, resulting in a high failure rate of the compressor. , poor unit stability.

Contents of the invention

In order to solve the above problems, the purpose of the present invention is to provide a forced cooling room refrigeration unit and its control method that can reduce energy consumption and reduce the failure rate of the compressor.

In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions: a forced cooling evaporative cooling unit, including a compressor refrigeration device, the compressor refrigeration device includes a compressor, a refrigerant pipeline, an expansion valve and an evaporator, and the compression The machine, expansion valve and evaporator are all installed on the refrigerant pipeline, and the refrigerant circulates in the refrigerant pipeline. After the refrigerant passes through the compressor and the expansion valve, it is liquid at low temperature and low pressure in the evaporator, including the water pipeline. A chilled water pump is installed on the water pipeline, and the chilled water pump drives the chilled water to flow in the water pipeline. The water pipeline passes through the evaporator, and the chilled water and refrigerant are heat exchanged in the evaporator, including a natural cooling device And multiple sensors for detecting temperature, the natural cooling device includes a water tower, a natural cooling pipe, a spray device and multiple sets of fans; the natural cooling pipe is installed on the water pipeline, and the top of the water tower is provided with a cooling cavity and a cooling cavity with an upward opening. The bottom section of the cooling chamber is connected to the bottom section of the cooling chamber. The natural cooling pipe is located in the cooling chamber. The chilled water first flows through the natural cooling pipe and then flows through the evaporator. There is cooling water in the cooling chamber, and the spray device pumps the cooling water into the cooling chamber. After the top, the cooling water is sprayed on the natural cooling pipe, and multiple sets of fans are installed at the opening of the cooling chamber. Such setting, through the recycling of chilled water by the water tower, can reduce the consumption of water resources of the unit and improve its water utilization rate. Through the setting of the cooling cavity and the heat dissipation cavity on the water tower, the cooling water falls naturally from a high place, and the water flowing through the water pipeline is water-cooled. Under the same temperature environment, the consumption of the compressor can be reduced; at the same time, another system is provided for the unit. A cooling method; the fan pumps the heat in the cooling chamber into the heat dissipation chamber and discharges it upwards. On the one hand, the cooling water can be cooled; on the other hand, the air in the cooling chamber can flow through the fan, and the water pipeline The chilled water inside is air-cooled to further improve the cooling effect, reduce energy consumption, reduce the compressor load, and reduce the failure rate of the compressor.

As preferably, the natural cooling pipe is located on the upper side of the communication section between the cooling chamber and the heat dissipation chamber, and the natural cooling pipe is a coil; the spraying device includes a spraying pipeline, a cooling water pump and a sprayer for spraying water, and the spraying pipe One end of the road communicates with the bottom of the cooling chamber, the cooling water pump is installed on the spray pipeline, the sprinkler is installed on the other end of the spray pipeline, and the sprayer is installed on the top of the cooling chamber. With such setting, the coil can increase the heat exchange area of the waterway and further improve the heat exchange efficiency.

Preferably, the refrigerant pipeline passes through the cooling cavity, and the refrigerant flows through the cooling cavity first, and then enters the evaporator through the expansion valve. With such an arrangement, the temperature of the refrigerant flowing in the refrigerant pipeline can be lowered by means of water cooling, and the load of the compressor can be reduced.

Preferably, a cooling coil is installed on the refrigerant pipeline, the cooling coil is located in the cooling cavity, and the spraying device sprays cooling water to the cooling coil to realize pre-cooling.

In this embodiment, the spraying device includes a cooling water pump, a spraying pipeline and

As a preference, a switching pipeline is provided on the water pipeline, and the chilled water directly passes through the evaporator through the switching pipeline. The switching pipeline is equipped with a mechanical refrigeration valve, and a natural cooling valve is installed on the water pipeline. The natural cooling valve is located between the switching pipeline and the natural between cooling tubes. With such arrangement, it is convenient to control the flow path and stability of the chilled water.

A control method of an evaporative cooling unit in a forced cooling room, based on the above-mentioned evaporative cooling unit in a forced cooling room, the control method of the refrigerating unit in a natural cooling state, the steps are as follows:

Step 1): The unit opens the natural cooling valve and closes the mechanical refrigeration valve;

Step 2): Start the chilled water pump, and make the chilled water flow through the natural cooling pipe through the set pump cycle time;

Step 3): Determine whether to turn on the cooling water pump according to the return temperature of the chilled water;

Step 4): According to the set temperature range of the return water temperature and the time during which the return water temperature is within the set range, the number of fans to be turned on is controlled. With such a setting, cooling is carried out through the combination of air cooling and water cooling, and the judgment and control of the recovery temperature of chilled water, the number of fans to be turned on, and the switching of cooling water pumps can reduce the energy consumption of the unit and ensure the stable operation of the unit.

As preferably, in the step, when the return water temperature of the chilled water is greater than the return water temperature range used for setting, the unit increases the number of fan openings with a cycle of 20 seconds; when the return water temperature of the chilled water is within the set return water temperature range In the return water temperature range, the number of fans to be turned on remains unchanged; when the return water temperature of the chilled water is lower than the set return water temperature range, the unit will reduce the number of fans to be turned on in a period of 15 seconds.

As a preference, the control method of the unit under the state of mechanical refrigeration, the steps are as follows:

Step 1): The unit opens the mechanical refrigeration valve and closes the natural cooling valve

Step 2): Turn on the chilled water pump, and make the chilled water pass through the evaporator through the set pump cycle time;

Step 3): According to the return water temperature of the chilled water, judge whether to turn on the cooling water pump;

Step 4): According to the temperature of the cooling water in the water tower, determine the number of fans to be turned on;

Step 5): Start the compressor to drive the refrigerant to circulate in the refrigerant pipeline. With such settings, the number of fans to be turned on and the water pumps to be turned on or off are controlled by conditions such as chilled water temperature and cooling water temperature, so as to optimize mechanical refrigeration, reduce energy consumption and compressor load while ensuring cooling effect.

Preferably, in the step, the compressor is started at the lowest output power when it is first turned on, and the user needs to adjust the output power of the compressor after the operation is stable. With such setting, through the adjustable output power of the compressor, while ensuring the refrigeration effect, the energy consumption of the compressor is reduced, and the load of the compressor is reduced.

Preferably, in the step, the power of the cooling water pump is adjusted according to the temperature of the cooling water in the cooling tower. Such setting can reduce the energy consumption of the unit and ensure the cooling effect.

The technical scheme of the present invention combines the two refrigeration modes of compressor refrigeration and natural cooling to reduce the overall energy consumption of the unit, reduce the load of the compressor, and reduce the failure rate of the compressor. By recycling the chilled water through the water tower, the water consumption of the unit can be reduced and the water utilization rate can be improved. Through the setting of the cooling cavity and the heat dissipation cavity on the water tower, the cooling water falls naturally from a high place, and the water flowing through the water pipeline is water-cooled. Under the same temperature environment, the consumption of the compressor can be reduced. The fan pumps the heat in the cooling chamber into the heat dissipation chamber and discharges it upwards. On the one hand, it can cool down the cooling water. Air-cooling treatment is carried out to further improve the cooling effect, reduce energy consumption, reduce the compressor load, and reduce the failure rate of the compressor. Part of the refrigerant pipeline is set in the cooling chamber, and the natural cooling device performs air-cooling and water-cooling on the refrigerant flowing in the refrigerant pipeline to realize pre-cooling of the refrigerant, thus further reducing the load of the compressor and ensuring the operation of the unit Stable and reduce energy consumption. In the control method, the chilled water return temperature and the cooling water temperature are controlled to control the power of the compressor, the power of the water pump and the number of fans turned on to further reduce the energy consumption of the unit.

Description of drawings

Fig. 1 is a structural schematic diagram of a forced cooling room refrigeration unit in an embodiment of the present invention.

In the drawings, arrows indicate the flow of refrigerant or chilled water. Dotted lines indicate refrigerant pipelines, and dotted lines indicate water pipelines. Reference signs: 1. Water pipeline; 11. Chilled water pump; 12. Natural cooling valve; 13. Mechanical refrigeration valve; 14. Switching pipeline; 15. Natural cooling pipe; 2. Refrigerant pipeline; 21. Compressor ; 22, evaporator; 3, water tower; 31, cooling cavity; 32, cooling cavity; 33, spray device; 331, cooling water pump; 332, spray pipeline; 34, fan;

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " The orientations or positional relationships indicated by "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise" are based on the attached The orientation or positional relationship shown in the figure is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a reference to this invention. Invention Limitations.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise clearly defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, a first feature being "on" or "under" a second feature may include direct contact between the first and second features, and may also include the first and second features Not in direct contact but through another characteristic contact between them. Moreover, "above", "above" and "above" the first feature on the second feature include that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. "Below", "beneath" and "under" the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

Example 1

A kind of forced cooling room evaporative refrigeration unit as shown in Figure 1, comprises compressor refrigerating device and natural cooling device, and compressor refrigerating device comprises compressor 21, evaporator 22, refrigerant pipeline 2 and water pipeline 1, so The compressor 21 and the evaporator 22 are arranged on the refrigerant pipeline 2, and the refrigerant pipeline 2 is also equipped with an expansion valve, a liquid storage tank, an oil separator, etc.; the water pipeline 1 includes a first water outlet and The first water inlet and the first water outlet are connected to the user end that needs to be cooled, and the water pipeline 1 passes through the evaporator 22, and the water pipeline 1 is provided with a chilled water pump 11; what flows in the water pipeline 1 is Chilled water, refrigerant flowing in the refrigerant pipeline 2. The process of evaporative cooling and cooling is as follows: the refrigerant is compressed by the compressor 21, from low-temperature and low-pressure gas to high-temperature and high-pressure gas, the high-temperature and high-pressure gas enters the oil separator for oil-liquid separation, and the high-temperature and high-pressure gas is cooled by heat exchange in the evaporative cooling device. After being filtered and dried by the liquid storage tank and filter, this part of the normal temperature and high pressure liquid enters the expansion valve for gas expansion, so that the normal temperature and high pressure gas and liquid mixture becomes a low temperature and low pressure refrigerant saturated liquid, and the low temperature and low pressure The refrigerant saturated liquid enters the evaporator 22 . Finally, the low-temperature and low-pressure refrigerant-saturated liquid exchanges heat with the chilled water passing through the evaporator 22; then the refrigerant evaporates and absorbs heat and evaporates again; the chilled water after heat exchange enters the user end from the water outlet.

In this embodiment, the natural cooling device includes a water tower 3, a natural cooling pipe 15, and a spray device 33. The top of the water tower 3 is provided with a cooling chamber 31 with an upward opening, and the natural cooling pipe 15 is installed on the water pipeline 1. The natural cooling pipe 15 is located in the upper section of the cooling cavity 31, and the spray device 33 includes a spray pipeline 332, and the spray pipeline 332 includes a second water inlet and a second water outlet, and the second water inlet and the cooling cavity 31 The bottom section of the second water outlet communicates with the top section of the cooling cavity 31 , a shower for spraying water is installed at the second water outlet, and a cooling water pump 331 is installed on the spray pipeline 332 . The process of natural cooling and cooling is as follows: the cooling water pump 331 pumps the cooling water at the bottom of the cooling chamber 31 to the top of the cooling chamber 31 and then sprays it on the top of the cooling chamber 31 by the sprayer. The sprayed cooling water is the frozen water flowing through the natural cooling pipe 15. The water cools down.

Further, the water tower 3 is also provided with a heat dissipation chamber 32 with an upward opening, the heat dissipation chamber 32 communicates with the cooling chamber 31, and a plurality of groups of fans 34 are installed on the top of the heat dissipation chamber 32, and the fans 34 pump the air in the heat dissipation chamber 32 to the outside; The natural cooling pipe 15 is located at the upper section of the cooling cavity 31, the cooling water sprayed by the spray device 33 falls on the natural cooling pipe 15, and exchanges heat with the frozen water flowing through the natural cooling pipe 15, and the cooling water after the heat exchange naturally Falling, the cooling water falls through the connecting section between the heat dissipation chamber 32 and the cooling chamber 31, and the fan 34 pumps the heat in the cooling water from the cooling chamber 31 to the heat dissipation chamber 32 and then discharges; thereby realizing the air cooling of the cooling water; at this time, the fan The air is driven to enter from the top of the cooling chamber and discharged from the top of the cooling chamber, so that the natural cooling pipe 15 is cooled by combining air cooling and water cooling. Further, the blower fan 34 discharges air upwards.

Further, the natural cooling pipe 15 is located above the communicating section between the radiator and the cooling cavity 31, and the communicating section between the cooling cavity 32 and the cooling cavity 31 is equipped with a ventilating grid to prevent the transition of water vapor from overflowing, while using a metal grid The heat exchange efficiency can be further improved.

In this embodiment, the chilled water in the water pipeline 1 passes through the natural cooling pipe 15 first, and then passes through the evaporator 22 . The natural cooling pipe 15 is a coiled pipe.

In this embodiment, the forced cooling evaporative cooling unit also includes an outdoor wet bulb for detecting the outdoor temperature, a plurality of sensors for detecting and merging the temperature, a control system for controlling the operation of the unit, and a control system for displaying the operation of the unit and operating the unit. HMI man-machine interface.

Further, the pipeline of the refrigerator passes through the cooling cavity 31 , and the cooling water sprayed by the spraying device 33 initially cools the refrigerant in the refrigerant pipeline 2 . In this embodiment, the section of the refrigerant pipeline 2 passing through the cooling cavity 31 is located between the oil separator and the liquid storage tank. Further, a cooling coil 35 is installed on the refrigerant pipeline 2, and the cooling coil 35 is located in the cooling chamber 31 of the water tower 3, and the spray device 33 sprays cooling water to the cooling coil 35, so that the refrigerator is initially cooled; With such arrangement, the cooling efficiency is further improved.

Further, the switching pipeline 14 is connected to the water pipeline 1, the chilled water can pass through the evaporator 22 directly through the switching pipeline 14, the mechanical refrigeration valve 13 is installed on the switching pipeline 14, and the natural cooling valve 13 is installed on the water pipeline 1 The cooling valve 12 and the natural cooling valve 12 are located between the switching pipeline 14 and the natural cooling pipe 15; such setting facilitates the control of the flow route and temperature of the chilled water. In this embodiment, the natural cooling pipe 15 is located at the lower side of the cooling coil 35 .

In this embodiment, the compressor 21 is a screw compressor.

Example 2

An operation mode of a forced cooling evaporative cooling unit: including a manual mode and an automatic mode.

In this embodiment, the manual mode refers to manually selecting the refrigeration mode of the unit according to the needs of the user. In the shutdown state, the user can select compressor cooling or natural cooling cooling through the HMI human-machine interface. Compressor refrigeration then opens mechanical refrigeration valve 13, closes natural cooling valve 12, adopts natural cooling then opens natural cooling valve 12, closes mechanical refrigeration valve 13. Detect the position of the valve after waiting for 60 seconds for the valve to switch, and if it is abnormal, it will stop and send an alarm. With this manual switching function, customers can switch according to their needs. For example, the low temperature in winter is set to natural cooling mode, and the high temperature in summer is set to compressor cooling.

In this embodiment, the automatic mode includes two modes of time-segment control and temperature control + limit time control.

Further, time period control, due to different time period temperatures, different cooling methods can be used to reduce energy consumption on the premise of meeting the cooling needs of users; for example, set a Beijing time period of 12:00-20:00, because The temperature is relatively high, it adopts natural cooling operation during this time period, and uses compressor refrigeration outside this time period.

Further, temperature control + limit time switching mode: according to the difference between indoor and outdoor temperature, different cooling methods are adopted; the control system automatically detects the outdoor wet bulb temperature, and switches to natural when the return temperature of chilled water is greater than or equal to the preset temperature Cooling mode; when the return water temperature is lower than the preset temperature and lasts for a period of time, and the return water temperature does not rise, it will automatically switch to compression refrigeration, or the accumulated natural cooling time exceeds the preset time and the compressor refrigeration will be forced to switch.

In this embodiment, in the automatic mode, the unit can complete the mode conversion by itself during the start-up process, without manual operation and supervision. For example, in the process of natural cooling operation, the natural cooling valve 12 is opened and the mechanical refrigeration valve 13 is closed. At this time, the system judges that the compressor needs to be turned on for cooling by detecting the wet bulb temperature. First, the fan 34 is turned off, and then the cooling water pump 331 is turned off. , while the chilled water pump 11 needs to continuously deliver water to the end and cannot be turned off. In order to ensure the smooth switching of the valve, the system reduces the power of the chilled water pump 11 to 10%, opens the mechanical refrigeration valve 13 in advance, and after the valve is opened for a waiting time of 2 seconds, then closes the natural cooling valve 12, and after the stabilization time of 1 second, the freezing The power of the water pump 11 is increased to the initial power operation of the compressor refrigeration mode, and then the cooling water pump 331 and the compressor 21 are continued to be turned on. Automatic switching and quick start-up can ensure that the user-side water flow and cooling capacity will not be affected. Such setting can ensure the stable operation of the unit and reduce the power of unit failure.

Example 3

In the method for controlling the unit in the forced cooling room, the unit also includes a control system for controlling the operation of the unit, and the steps are as follows:

In compressor refrigeration mode; the control method of the unit, the steps are as follows:

Step 1: The unit opens the mechanical refrigeration valve 13 and closes the natural cooling valve 12, so that the chilled water flows through the natural cooling pipe 15 first and then through the evaporator 22.

Step 2: Turn on the chilled water pump 11 to circulate the chilled water in the water pipeline 1 through the set pump cycle time, and the water flow switch on the chilled side detects the water flow signal and feeds it back to the control system.

Step 3: Determine whether to turn on the cooling water pump 331 according to the return temperature of the chilled water.

Step 4: According to the temperature of the cooling water in the water tower 3, determine the number of fans 34 to be turned on.

Step 5: At this time, the start-up conditions are met, and the compressor 21 is started to drive the refrigerant to circulate in the refrigerant pipeline 2 .

Furthermore, in step 2, in order to ensure the safe start-up of the unit, the chilled water pump 11 operates at the preset initial operating power at the beginning of the start-up, so that the water flow can fully circulate. The power of the chilled water pump 11 is adjusted based on the calculated temperature difference between "inlet water temperature and outlet water temperature". When the user's cooling capacity demand decreases, the power of the chilled water pump 11 is reduced when the temperature difference between the inlet and outlet water becomes smaller, and when the user's cooling capacity demand increases, the power of the chilled water pump 11 is increased when the temperature difference between the inlet and outlet water becomes larger. At the same time, there is a minimum lower limit power to ensure normal water flow. The power of the chilled water pump 11 is adjusted so that the chilled water pump 11 can achieve the best energy saving.

In step 3, in order to ensure safe start-up of the unit, the power of the cooling water pump 331 is adjusted according to the temperature of the cooling water in the cooling tower. The cooling water pump 331 operates at a preset initial operating power. When the cooling water temperature in the water tower 3 is less than 15 degrees, the initial operating power of the cooling water pump 331 operates at 50% of the total power; when the cooling water temperature in the water tower 3 is greater than or equal to When the temperature is between 15 degrees and less than 20 degrees, the initial operating power of the cooling water pump 331 runs at 70% of the total power; The temperature of the internal cooling water is too low, and the unit starts up normally when the temperature of the cooling water in the water tower 3 is too high in summer. After the compressor 21 runs stably, the system performs PID adjustment of the power of the cooling water pump 331 according to the condensation temperature of the cooling water in the water tower 3. When the condensation temperature of the cooling water in the water tower 3 is greater than the set temperature, the power of the cooling water pump 331 is increased; When the condensing temperature of the cooling water in the water tower 3 is lower than the set temperature, reduce the power of the cooling water pump 331, and set the lowest lower limit power simultaneously to ensure normal water flow. This power condition enables the cooling water pump 331 to achieve the best energy saving, and makes the unit run in a stable state, which is automatically adjusted according to the change of working conditions.

In step 4, when the cooling water temperature is greater than or equal to 32 degrees, the first fan 34 is turned on, the second fan 34 is turned on when the cooling water temperature is greater than or equal to 34 degrees, and the third fan 34 is turned on when the cooling water temperature is greater than or equal to 36 degrees A blower fan 34 opens the fourth blower fan 34 when the cooling water temperature is greater than or equal to 38 degrees. Turn off the fourth fan 34 when the cooling water temperature is less than 37 degrees, turn off the third fan 34 when the cooling water temperature is less than 35 degrees, turn off the second fan 34 when the cooling water temperature is less than 33 degrees, and turn off the second fan 34 when the cooling water temperature is less than 31 degrees The first blower 34 is turned off. Through the coordination of multiple fans 34, the unit runs stably, and is automatically adjusted according to changes in working conditions, further reducing energy consumption.

In step 5, the compressor 21 is started at the lowest load when it is first started, and after the operation is stable, the operating capacity is adjusted according to the return water temperature. When the return water temperature is greater than or equal to the set range, the system calculates that the compressor 21 is optimal Operating capacity, by adjusting the loading valve of the compressor 21, the compressor 21 is loaded to the required capacity to run. When the return water temperature is higher than the set value and lower than the user’s set range, the compressor 21 is not loaded or unloaded at this time, so that the unit The outlet water temperature remains stable. When the return water temperature is less than or equal to the temperature set by the user, the system calculates the optimal operating capacity of the compressor 21, and adjusts the unloading valve of the compressor 21 to unload the compressor 21 to the required capacity. Automatically adjust the operating capacity of the compressor 21 according to the cooling capacity demand of the user to ensure the stable operation of the unit

In the natural cooling mode, the control method of the unit is as follows:

Step 1: When the "start" button is pressed, the unit opens the natural cooling valve 12, closes the mechanical refrigeration valve 13, and makes the chilled water flow through the natural cooling coil for heat exchange.

Step 2: Turn on the chilled water pump 11 .

Step 3: Determine whether to start the cooling water pump (331) according to the return temperature of the chilled water.

Step: 4: According to the set temperature range where the return water temperature is and the time when the return water temperature is within the set range, control the number of fans (34) to be turned on.

Further, in step 2, when the chilled water pump 11 is just turned on, it operates at the preset initial operating power to make the water flow fully circulate. Based on the calculated temperature difference, the PID adjusts the power of the chilled water pump 11 . When the user's cooling capacity demand decreases, the power of the chilled water pump 11 decreases when the temperature difference between the inlet and outlet water becomes smaller; when the user's cooling capacity demand increases, the power of the chilled water pump 11 increases when the user's cooling capacity demand increases and the temperature difference between the inlet and outlet water becomes larger. At the same time, there is a minimum lower limit power to ensure normal water flow. This power adjustment enables the chilled water pump 11 to achieve optimal energy saving. In order to ensure the safe start-up of the unit.

Further, in step 3, the cooling water pump 331 runs at full power.

Further, in step 4, after the cooling water pump 331 is started, it is detected that in the water pipeline 1, when the return water temperature is greater than or equal to the return water temperature range set by the user, the system increases the number of fans 34 at intervals of 29; When the return water temperature is within the return water temperature range set by the user, the number of fans 34 does not increase or decrease at this time, so that the unit outlet water temperature remains stable; when the return water temperature is less than or equal to the return water temperature set by the user, the system starts with 15 seconds is an interval to reduce the number of fans 34 until all of them are turned off. Automatically increase or decrease the number of fans 34 turned on according to the user's cooling capacity demand to ensure stable operation of the unit.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations to the present invention. Variations, modifications, substitutions, and modifications to the above-described embodiments are possible within the scope of the present invention.

Claims (4)

1. The utility model provides a control method of strong cold room evaporation cooling unit, be used for controlling strong cold room evaporation cooling unit, including compressor refrigerating plant, compressor refrigerating plant includes compressor (21), refrigerant pipeline (2), expansion valve and evaporimeter (22), compressor (21), expansion valve and evaporimeter (22) are all installed on refrigerant pipeline (2), refrigerant pipeline (2) inner loop flows there is the refrigerant, the refrigerant is through low temperature low pressure liquid form in evaporimeter (22) behind compressor (21) and the expansion valve, still include water route pipeline (1), install frozen water pump (11) on water route pipeline (1), will drive refrigerated water through frozen water pump (11) and flow in water route pipeline (1), water route pipeline (1) passes evaporimeter (22), carry out heat exchange treatment to frozen water and refrigerant in evaporimeter (22), its characterized in that: the system also comprises a natural cooling device and a plurality of sensors for detecting temperature, wherein the natural cooling device comprises a water tower (3), a natural cooling pipe (15), a spraying device (33) and a plurality of groups of fans (34); the natural cooling pipe (15) is installed on the water channel pipeline (1), a cooling cavity (31) with an upward opening and a heat dissipation cavity (32) are arranged at the top of the water tower (3), the bottom section of the cooling cavity (31) is communicated with the bottom section of the heat dissipation cavity (32), the natural cooling pipe (15) is located in the cooling cavity (31), chilled water firstly flows through the natural cooling pipe (15) and then flows through the evaporator (22), cooling water is arranged in the cooling cavity (31), a spraying device (33) pumps the cooling water to the top of the cooling cavity (31) and then sprays the cooling water onto the natural cooling pipe (15), a plurality of groups of fans (34) are all installed at the opening of the heat dissipation cavity (32), and the fans (34) exhaust air upwards;

the natural cooling pipe (15) is positioned on the upper side of the communicating section of the cooling cavity (31) and the heat dissipation cavity (32), and the natural cooling pipe (15) is a coil pipe; the spraying device (33) comprises a spraying pipeline (332), a cooling water pump (331) and a sprayer for spraying water, one end of the spraying pipeline (332) is communicated with the bottom of the cooling cavity (31), the cooling water pump (331) is installed on the spraying pipeline (332), the sprayer is installed at the other end of the spraying pipeline (332), and the sprayer is installed at the top of the cooling cavity (31);

a refrigerant pipeline (2) penetrates through the cooling cavity (31), and refrigerant firstly flows through the cooling cavity (31) and then enters the evaporator (22) through an expansion valve;

a cooling coil (35) is arranged on the refrigerant pipeline (2), the cooling coil (35) is positioned in the cooling cavity (31), and the spraying device (33) sprays cooling water to the cooling coil (35) to realize pre-cooling;

a switching pipeline (14) is arranged on the water channel pipeline (1), the chilled water directly passes through the evaporator (22) through the switching pipeline (14), a mechanical refrigeration valve (13) is installed on the switching pipeline (14), a natural cooling valve (12) is installed on the water channel pipeline (1), and the natural cooling valve (12) is located between the switching pipeline (14) and the natural cooling pipe (15);

the unit comprises a natural cooling state and a mechanical refrigeration state, and the unit can judge that the compressor needs to be started for refrigeration according to the wet bulb temperature in the natural cooling state; the running state of the unit can be adjusted manually or within a preset time period;

the control method of the refrigerating unit in the natural cooling state comprises the following steps:

step 1): the unit opens a natural cooling valve (12) and closes a mechanical refrigeration valve (13);

step 2): starting a freezing water pump (11); specifically, when the frozen water pump (11) is started, the frozen water pump (11) operates according to preset initial operation power to enable water flow to be fully circulated, and after stabilization time, the control system adjusts the power of the frozen water pump (11) by PID according to the calculated temperature difference of 'inlet water temperature and outlet water temperature' of a user use side;

step 3): judging whether to start a cooling water pump (331) according to the return water temperature of the chilled water; the cooling water pump (331) runs at full power after being started;

step 4): controlling the opening number of the fans (34) according to the set temperature range of the return water temperature and the time of the return water temperature in the set range;

the control method of the unit under the mechanical refrigeration state comprises the following steps:

step 1): the unit opens the mechanical refrigeration valve (13) and closes the natural cooling valve (12);

step 2): starting a freezing water pump (11), and enabling the freezing water to pass through an evaporator (22) according to the set water pump circulation time; specifically, the freezing water pump (11) operates according to the preset initial operation power to ensure that the water flow is fully circulated;

step 3): judging whether to start a cooling water pump (331) according to the return water temperature of the chilled water; after the cooling water pump (331) is started, the cooling water pump (331) operates according to a preset initial operating power, and when the temperature of cooling water in the water tower (3) is less than 15 ℃, the initial operating power of the cooling water pump (331) operates according to 50% of the total power; when the temperature of the cooling water in the water tower (3) is greater than or equal to 15 ℃ and less than 20 ℃, the initial operation power of the cooling water pump (331) is operated according to 70 percent of the total power; otherwise, the cooling water pump (331) runs at full load;

step 4): judging the number of the fans (34) which are started according to the temperature of cooling water in the water tower (3);

step 5): starting the compressor (21) to drive the refrigerant to circulate in the refrigerant line (2); the compressor (21) is started according to the lowest load, after the compressor (21) operates stably, the compressor (21) dynamically adjusts the operation capacity of the compressor (21) according to the return water temperature, and the unit operation stability is guaranteed; after the compressor (21) operates stably, the system adjusts the power of the refrigerating water pump (11) according to the calculated temperature difference between the water inlet temperature and the water outlet temperature of the user use side.

2. The control method of the forced cooling compartment evaporative cooling unit as claimed in claim 1, wherein: in the step 4) of the control method of the refrigerating unit under the natural cooling state, when the return water temperature of the chilled water is greater than the set return water temperature range, the unit increases the number of the fans (34) which are opened in a period of 20 seconds; when the return water temperature of the chilled water is in the return water temperature range for setting, the opening number of the fans (34) is unchanged; when the return water temperature of the chilled water is smaller than the set return water temperature range, the number of the fans (34) opened is reduced by taking 15 seconds as a period.

3. The control method of the forced cooling compartment evaporative cooling unit as claimed in claim 1, wherein: in step 3) of the control method of the refrigerating unit under the mechanical refrigeration state, the power of the cooling water pump (331) is adjusted according to the temperature of cooling water in the cooling tower.

4. The control method of the forced cooling compartment evaporation cooling unit as claimed in claim 1, wherein: in the step 5) of the control method of the refrigerating unit under the mechanical refrigeration state, after the compressor (21) operates stably, when the return water temperature is greater than or equal to a set range, the compressor (21) is loaded to the required capacity to operate by adjusting a loading valve of the compressor (21); when the return water temperature is greater than the set value and less than the set range of a user, the compressor (21) is not loaded or unloaded; the temperature of the water outlet of the unit is kept stable; when the temperature of the return water is less than or equal to the set temperature of a user, the compressor (21) is unloaded to the required capacity for operation by adjusting an unloading valve of the compressor (21).

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