CN105444380A - Cold water system - Google Patents

Abstract

The invention relates to the technical field of energy saving and emission reduction, in particular to a cold water system. It is used to solve the problem that the air conditioning system consumes a large amount of energy in the process of using the chiller to produce chilled water in the prior art. A cold water system provided by an embodiment of the present invention includes: a heat exchanger, an input end of the heat exchanger is connected to a cold recovery device, and an output end of the heat exchanger is connected to a chiller. Among them, the cooling recovery device is provided with a coil pipe and a fan unit for supplying air to the coil pipe, and a three-way valve is provided between the water outlet pipe of the chiller and the water outlet pipe at the output end of the heat exchanger; the first valve of the three-way valve It is selectively communicated with the outlet pipe of the chiller, the second valve of the three-way valve is selectively communicated with the water inlet pipe of the chiller, and the third valve of the three-way valve is communicated with the outlet pipe of the heat exchanger. The cold water system provided by the embodiments of the present invention can utilize natural air cooling capacity at a lower cost, thereby greatly reducing energy consumption.

Description

a cold water system

technical field

The invention relates to the technical field of energy saving and emission reduction, in particular to a cold water system.

Background technique

With the development of the times, semiconductor factories, electronic product manufacturing and other industries and regions have higher and higher requirements on the environment, and a working environment with constant temperature and humidity is required throughout the year. In order to maintain a constant temperature and humidity working environment, it is necessary to use an air-conditioning system to adjust the working environment. The air-conditioning system usually uses chilled water for temperature adjustment. At the same time, some production equipment in industrial manufacturing also needs to use cooling water to cool down during operation. The cooling water is obtained through heat exchange with chilled water. The cold water system referred to in this patent covers the water system that needs to be cooled, including It is not limited to chilled water, cooling water, and the like.

As shown in FIG. 1 , in the prior art, a schematic diagram of the composition and structure of chillers commonly used in air-conditioning systems to produce chilled water. Including: compressor, the compressor compresses the refrigerant into high-temperature and high-pressure gas and sends it to the condenser for heat exchange with cooling water. High, high-temperature cooling water is driven by the cooling water pump to the cooling tower for heat exchange with the atmosphere. After the temperature is lowered, it returns to the condenser of the chiller. Wherein, the cooling water pump is also used to circulate the cooling water in the cooling tower and the condenser. After the refrigerant and cooling water are converted into a liquid state after heat exchange in the condenser, the liquid refrigerant is sent to the evaporator, and the liquid refrigerant is converted into a gas state through a throttle valve or an expansion valve in the evaporator, and the liquid refrigerant Refrigerant will release cold energy when it is converted into gaseous state through throttling valve or expansion valve in the evaporator, and liquid refrigerant will return from the air conditioning system when it is converted into gaseous state through throttling valve or expansion valve in the evaporator. The high-temperature chilled water coming out of the water pipe undergoes heat exchange to cool the chilled water, and the chilled water after heat exchange is transported to the water inlet pipe of the air conditioning system by the chilled water pump, so as to achieve the purpose of cooling and dehumidification. However, air conditioning systems consume a lot of energy in the process of using chillers to produce chilled water.

In winter, the outdoor temperature in most areas is much lower than the chilled water temperature (6-12°C) produced by the chiller. If the natural air cooling capacity can be utilized at a lower cost, energy consumption will be greatly reduced, but there is currently no There are systems that use natural air cooling to create chilled water.

Contents of the invention

The invention provides a cold water system, which is used for reducing the energy consumption of an air conditioning system in the process of using a water chiller to produce chilled water.

An embodiment of the present invention provides a cold water system, including: a heat exchanger, the input end of the heat exchanger is connected to a cold recovery device, and the output end of the heat exchanger is connected to a chiller;

A coil pipe and a fan unit for supplying air to the coil pipe are arranged in the cold recovery device, and the inlet and outlet of the coil pipe are communicated with the outlet pipe and the inlet pipe of the input end of the heat exchanger respectively. The inlet pipe of the coil is provided with a first circulation pump, and the first circulation pump is used to circulate the refrigerant in the coil;

A three-way valve is arranged between the water outlet pipe of the chiller and the water outlet pipe at the output end of the heat exchanger;

The first valve of the three-way valve is selectively communicated with the water outlet pipe of the chiller, the second valve of the three-way valve is selectively communicated with the water inlet pipe of the chiller, and the third valve of the three-way valve is The valve communicates with the water outlet pipe of the heat exchanger.

Preferably, the cold water system further includes: a first temperature sensor and a controller;

The first temperature sensor is arranged on the outlet pipe of the output end of the heat exchanger, and the first temperature sensor is used to monitor the temperature of the chilled water in the outlet pipe of the output end of the heat exchanger;

The controller is electrically connected to the first temperature sensor and the three-way valve, and is used to control the second valve of the three-way valve when the temperature detected by the first temperature sensor is higher than a set value Opening: when the temperature detected by the first temperature sensor is equal to or lower than the set value, the first valve controlling the three-way valve is opened.

Preferably, the cold water system further includes: a second temperature sensor;

The second temperature sensor is arranged on the inlet pipe of the output end of the heat exchanger, and the second temperature sensor is used to monitor the temperature of the chilled water in the inlet pipe of the output end of the heat exchanger;

The controller is also electrically connected to the second temperature sensor, and is used to control the second valve of the three-way valve to open when the temperature monitored by the second temperature sensor is higher than the outdoor temperature.

Preferably, the number of the fan units is one group;

The controller is also electrically connected to the fan unit, and is used to lower the frequency of the fan unit when the temperature detected by the first temperature sensor is equal to or lower than the set value; When the temperature detected by the temperature sensor is higher than the set value, the frequency of the fan unit is increased.

Preferably, the number of the fan groups is multiple groups;

The controller is also electrically connected to the fan unit, and is used to shut down part of the fan unit when the temperature monitored by the first temperature sensor is equal to or lower than the set value; when the first temperature sensor monitors When the temperature reached is higher than the set value, increase the frequency of the currently turned on fan unit and/or turn on the currently turned off fan unit.

Preferably, the cold water system further includes: a damper and a damper actuator, the damper is arranged inside the fan unit, and the damper actuator is used to control the opening of the damper;

The controller is also electrically connected to the air valve actuator, and is used for when the temperature monitored by the first temperature sensor is equal to or lower than the set value, and only one group of fans is running and its frequency reaches the minimum allowable When the frequency is running, the opening of the air valve is adjusted by the air valve actuator.

Preferably, the cold water system further includes: a refrigerant expansion tank, and the refrigerant expansion tank communicates with the outlet pipe at the input end of the heat exchanger.

According to a cold water system provided by an embodiment of the present invention, the cold water system includes: a heat exchanger, the input end of the heat exchanger is connected to a cold recovery unit, and the output end of the heat exchanger is connected to a chiller; the cold recovery unit A coil and a fan unit for supplying air to the coil are installed in the center. The inlet and outlet of the coil are respectively connected with the outlet pipe and the inlet pipe of the input end of the heat exchanger. The coil is provided with a first circulation pump, and the first circulation The pump is used to circulate the refrigerant in the coil; the water inlet pipe of the chiller is connected with the inlet pipe of the output end of the heat exchanger, and a three-way valve is set between the water outlet pipe of the chiller and the outlet pipe of the output end of the heat exchanger; the three-way valve The first valve is selectively communicated with the water outlet pipe of the chiller, the second valve of the three-way valve is selectively communicated with the water inlet pipe of the chiller, and the third valve of the three-way valve is communicated with the outlet pipe of the output end of the heat exchanger. Using the cold water system provided by the present invention, according to the outdoor temperature and the temperature of the chilled water entering the air-conditioning system, chilled water can be produced in combination with a chiller recovery device; chilled water can also be produced only in the cooling capacity recovery mode Also can only use chiller to make chilled water; It can be seen that using the chilled water system provided by the present invention to make chilled water no longer only utilizes chiller to make chilled water, and even all need not use chiller to make chilled water under certain specific circumstances. Therefore, adopting the cold water system provided by the present invention can reduce the energy consumption of the air conditioning system in the process of using the chiller to produce chilled water.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Description of drawings

The accompanying drawings described herein are included to provide a further understanding of the invention and constitute a part of this application. In the attached picture:

Fig. 1 is a structural schematic diagram of a chiller in the prior art;

Fig. 2 is a schematic structural diagram of a cold water system provided by Embodiment 1 of the present invention;

Fig. 3 is a schematic structural diagram of a cold water system provided by Embodiment 2 of the present invention;

Fig. 4 is a schematic structural diagram of a cold water system provided by Embodiment 3 of the present invention;

Fig. 5 is a schematic structural diagram of a cold water system provided by Embodiment 4 of the present invention.

detailed description

An embodiment of the present invention provides a cold water system, which is used to reduce energy consumption in producing cold water when the outside temperature is equal to or lower than the cold water temperature.

The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are illustrated. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention.

The following description of at least one exemplary embodiment is merely illustrative in nature and in no way taken as limiting the invention, its application or uses.

As shown in Figure 2, the cold water system provided by Embodiment 1 of the present invention includes: a heat exchanger, the input end of the heat exchanger is connected to a cold recovery device, and the output end of the heat exchanger is connected to a chiller; A coil and a fan unit for supplying air to the coil are arranged in the volume recoverer, the inlet of the coil is connected with the outlet pipe at the input end of the heat exchanger, and the outlet of the coil is connected with the inlet pipe at the input end of the heat exchanger, the said The inlet pipe on the coil is provided with a first circulation pump, and the first circulation pump is used to circulate the refrigerant in the coil; the outlet pipe of the chiller and the outlet pipe at the output end of the heat exchanger are provided There is a three-way valve; the first valve of the three-way valve is selectively connected with the water outlet pipe of the chiller, the second valve of the three-way valve is selectively connected with the water inlet pipe of the chiller, and the third valve of the three-way valve is connected with the output pipe of the heat exchanger The outlet pipe at the end is connected.

Further, the first circulation pump can also be on the outlet pipe of the coil. The first circulation pump can be operated by frequency conversion. In addition, the power, flow rate, and head of the first circulation pump can be set according to the user's demand for chilled water.

Further, the cold water system provided in Embodiment 1 may further include a refrigerant expansion tank (not shown in FIG. 2 ). The refrigerant expansion tank communicates with the outlet pipe at the input end of the heat exchanger. The refrigerant expansion tank is equipped with refrigerant used by the coil in the refrigerant recovery device, and the refrigerant can be ethylene glycol or other substances with a lower freezing point. After the refrigerant and cold water exchange heat in the heat exchange, the temperature of the refrigerant will rise, and as the temperature of the refrigerant rises, the volume will expand, and the pressure of the outlet pipe at the input end of the heat exchanger will increase. By setting the refrigerant expansion tank on the outlet pipe at the input end of the heat exchanger, the expansion and contraction of the refrigerant can be absorbed or compensated, thereby reducing the pressure of the outlet pipe at the input end of the plate heat exchanger.

Further, a thermometer T1 (not shown in FIG. 2 ) may also be provided on the outlet pipe of the coil in the cold recovery device. Thermometer T1 is used for on-site inspection personnel to grasp the temperature of the refrigerant coming out of the coil outlet.

Further, a chilled water pump (not shown in FIG. 2 ) may also be provided on the water inlet pipe of the chiller. The chilled water pump is used to circulate chilled water between the air-conditioning system and the chiller; the power, flow, and head of the chilled water pump can be set by the staff according to the chilled water demand of the air-conditioning system.

Further, a chilled water pump (not shown in FIG. 2 ) may also be provided on the inlet pipe at the output end of the heat exchanger. The chilled water pump is used to drive the high-temperature chilled water from the outlet pipe of the air conditioning system, that is, the return pipe, into the heat exchanger. The power, flow, and head of the chilled water pump will be set by the staff according to the demand for chilled water in the air conditioning system.

In the above cold water system, the heat exchangers may be plate heat exchangers, floating head heat exchangers, shell and tube heat exchangers and other types of heat exchangers. The heat exchanger is used to exchange heat between the refrigerant coming out of the outlet pipe of the coil in the cold recovery device and the chilled water entering from the inlet pipe at the output end of the heat exchanger.

In the above cold water system, the first valve of the three-way valve is one of the two outlets of the three-way valve, the second valve of the three-way valve is the other one of the two outlets of the three-way valve, and the The third valve is the inlet of the three-way valve. In this embodiment, the third valve of the three-way valve, that is, the inlet of the three-way valve, is connected to the water outlet at the output end of the heat exchanger.

The water chiller in the above water chilling system may be the water chiller shown in Fig. 1 or other types of water chiller, and there may be one chiller or multiple chillers.

The specific working process of the above-mentioned cold water system is: when the outdoor temperature is equal to or lower than the chilled water temperature (6-12°C), for example, in winter, when the outdoor temperature is 0°C. The fan unit sends the outdoor cold air to the coil in the cooling recovery device, and the coil is filled with refrigerant, so that the outdoor cold air delivered by the fan unit can cool down the refrigerant in the coil, and cool down the outdoor cold air. The final refrigerant is transported to the heat exchanger; the refrigerant exchanges heat with the high-temperature chilled water output from the outlet pipe of the air conditioning system in the heat exchanger, and then the chilled water after heat exchange with the refrigerant in the heat exchanger is transported to The three-way valve selectively communicates with the first outlet or the second outlet according to the temperature of the chilled water after heat exchange.

Using the above-mentioned cold water system, when the three-way valve opens the first valve, the chilled water output from the outlet pipe at the output end of the heat exchanger is directly sent to the air conditioning system, without going through the chiller to cool the chilled water, thereby avoiding energy consumption by the chiller consumption; when the three-way valve opens the second valve, the chilled water output from the outlet pipe at the output end of the heat exchanger will be delivered to the chiller, which will be further refrigerated by the chiller before being delivered to the air conditioning system; The chilled water has been preliminarily cooled by the refrigerant in the heat exchanger. At this time, if multiple chillers are running in parallel, it will be decided whether to shut down one or more chillers according to the load of the chillers. Therefore, In this case, using the chiller to produce chilled water will reduce the energy consumption of the chiller.

As shown in Figure 3, it is a cold water system provided by Embodiment 2 of the present invention,

The cold water system provided by Embodiment 2 of the present invention is based on the cold water system provided by Embodiment 1, and further includes: a first temperature sensor and a controller, wherein the first temperature sensor is arranged on the outlet pipe at the output end of the heat exchanger, and the second A temperature sensor is used to monitor the temperature of the chilled water in the outlet pipe at the output end of the heat exchanger; the controller is electrically connected to the first temperature sensor and the three-way valve, and the controller can collect the temperature monitored by the first temperature sensor from the heat exchanger to the refrigerant. The temperature of chilled water after heat exchange.

The above-mentioned controller may be a programmable logic controller (Programmable Logic Controller, PLC for short), may also be a single-chip microcomputer constituted by other electrical components, and may also be other electronic devices with this control function. The controller can calculate the unit cost of producing chilled water using the chiller shown in Figure 1 according to the input configuration parameters and actual operating parameters of the chiller. In addition, according to the input power of the fan in the cooling water system in the first embodiment and the power of the first circulating pump, the controller can calculate that when the outdoor temperature is lower than a certain temperature value, the temperature of the cooling water system in the first embodiment is used. cost. In addition, the controller can also be electrically connected to the first circulation pump, which can be a frequency conversion control water pump, and the controller can set the operating frequency of the first circulation pump according to the demand of the air conditioning system for chilled water.

Further, a chilled water pump (not shown in Fig. 3 ) may also be provided on the water inlet pipe of the chiller, and the chilled water pump is used to circulate chilled water between the air conditioning system and the chiller; the chilled water pump can be operated by frequency conversion , the controller can be electrically connected with the chilled water pump, and the controller can automatically set the operating frequency of the chilled water pump.

Further, a chilled water pump (not shown in FIG. 3 ) may also be provided on the inlet pipe at the output end of the heat exchanger, and the chilled water pump is used to drive and input the high-temperature chilled water from the outlet pipe of the air conditioning system, that is, the return pipe. in the heat exchanger. The chilled water pump can operate with variable frequency, the controller can be electrically connected with the chilled water pump, and the controller can also automatically set the operating frequency of the chilled water pump.

Further, the number of fan units in the cold water system may be one or more groups, and the fan units may be electrically connected to the controller.

When the number of fan units in the cold water system is one group, if the temperature detected by the first temperature sensor is equal to or lower than the set value of the air conditioning system, the set value of the air conditioning system can also be a range, for example, the first The temperature monitored by the temperature sensor is 4°C, and the set value of the air conditioning system is 6°C or 6-12°C, the controller can adjust the temperature monitored by the first temperature sensor by lowering the frequency of the current fan unit; if the first The temperature detected by the temperature sensor is higher than the set value of the air-conditioning system. For example, the temperature monitored by the first temperature sensor is 13°C, and the set value of the air-conditioning system is 6°C or 6-12°C. The frequency of the fan unit is adjusted based on the temperature monitored by the first temperature sensor.

When the number of fan groups in the cold water system is multiple groups, for example, the number of fan groups is 5 groups and 3 groups are currently turned on, if the temperature detected by the first temperature sensor is equal to or lower than the set value of the air conditioning system, The set value of the air-conditioning system can also be a range, for example, the temperature monitored by the first temperature sensor is 4°C, and when the set value of the air-conditioning system is 6°C or 6-12°C, the controller can turn it on by turning it off. Part of the fan units can adjust the temperature detected by the first temperature sensor. For example, the controller can turn off 1 or 2 groups of the 3 groups of fans currently turned on; when the temperature detected by the first temperature sensor is higher than the setting of the air conditioning system When setting the value, for example, the temperature monitored by the first temperature sensor is 13°C, and the set value of the air-conditioning system is 6°C or 6-12°C, the controller can increase the frequency of the currently turned on fan unit and/or set the Turn on the currently closed fan unit to adjust the temperature monitored by the first temperature sensor. For example, the controller can increase the frequency of the 3 groups of fans that are currently turned on or turn on the other 2 groups of fan units that are currently closed or the controller Increase the frequency of the 3 sets of fans that are currently turned on and turn on the other 2 sets of fans that are currently turned off.

Further, the cold water system may also include: a damper and a damper actuator (not shown in FIG. 3 ), the damper is arranged inside the fan unit, and the damper actuator is used to control the opening of the damper; The controller is electrically connected, if the temperature detected by the first temperature sensor is equal to or lower than the set value of the air conditioning system and only one group of fans is running and its frequency reaches the minimum allowable operating frequency, the opening of the air valve is lowered through the air valve actuator . For example, the temperature monitored by the first temperature sensor is 4°C, and the set value of the air conditioning system is 6°C or 6-12°C. If the temperature detected by the first temperature sensor is higher than the set value of the air conditioning system and only one group of fans is running and its frequency reaches the minimum allowable operating frequency, for example, the temperature monitored by the first temperature sensor is 13°C, and the setting The fixed value is 6°C or 6-12°C, and the opening of the damper is adjusted up through the damper actuator.

In the specific implementation, the specific control process of the fan unit, the frequency of the fan unit, the frequency of the first circulation pump, the frequency of the chilled water pump and the damper actuator by the controller is as follows:

In the initial operating state of the cold water system: start the chilled water pump on the inlet pipe at the output end of the heat exchanger, and run at power frequency; start the first circulation pump, and run at power frequency; start the fan unit, and run at power frequency. The controller can automatically adjust the opening or closing of the fan unit, and the controller can also adjust the operating frequency of the first circulating pump and the chilled water pump. For example, when the temperature of the chilled water set by the air conditioning system is 6°C, and the temperature of the chilled water coming out of the heat exchanger monitored by the first temperature sensor collected by the controller is 0°C, the controller automatically controls the shutdown of some fan units; when When there is only the last group of fan units left, the temperature of the chilled water coming out of the heat exchanger monitored by the first temperature sensor collected by the controller becomes 2°C, which is still 6°C lower than the temperature of the chilled water set by the user. At this time, the controller The controller automatically lowers the frequency of the last group of fans; if the controller has lowered the frequency of the last group of fans to the lowest allowable operating frequency, the temperature of the chilled water coming out of the heat exchanger monitored by the first temperature sensor collected by the controller changes. 3°C, which is still 6°C lower than the chilled water temperature set by the user. At this time, the controller automatically lowers the frequency of the first circulation pump and/or lowers the frequency of the chilled water pump on the inlet pipe at the output end of the heat exchanger. If the controller automatically lowers the frequency of the chilled water pump on the inlet pipe at the output end of the heat exchanger to the minimum operating frequency of the chilled water pump, the temperature of the chilled water coming out of the heat exchanger monitored by the first temperature sensor collected by the controller The temperature becomes 4°C, which is still 6°C lower than the temperature of chilled water set by the user. Meet the user's requirements for chilled water temperature. The time required for the above adjustment process can be preset by the controller, for example, within 1 minute or 30 seconds after the cold water system starts to run, the above adjustment process will be automatically completed by the controller.

The working process of the cold water system in this embodiment is: if the temperature of the chilled water that comes out of the heat exchanger and exchanges heat with the refrigerant as monitored by the first temperature sensor collected by the controller is higher than the set value of the air conditioning system, the air conditioning system The set value can also be a range. For example, when the temperature monitored by the first temperature sensor collected by the controller is 13°C, and the set value of the air conditioning system is 6°C or 6-12°C, the controller controls the three-way valve The second valve is connected, and the chilled water output from the outlet pipe at the output end of the heat exchanger is sent to the chiller, which is further cooled by the chiller and then sent to the air conditioning system, so as to meet the demand of the air conditioning system for chilled water. At this time, if multiple chillers are running in parallel, it will be decided whether to shut down one or more chillers according to the load of the chillers. If the first temperature sensor collected by the controller monitors the temperature of the chilled water coming out of the heat exchanger after heat exchange with the refrigerant is equal to or lower than the set value of the air conditioning system, the set value of the air conditioning system can also be within a range For example, when the temperature collected by the controller and monitored by the first temperature sensor is 4°C, and the set value of the air conditioning system is 6°C or 6-12°C, the controller controls the first valve of the three-way valve to communicate.

Using the above-mentioned cold water system, when the temperature monitored by the first temperature sensor collected by the controller is higher than the set value of the air conditioning system, the controller controls the second valve of the three-way valve to open. At this time, the output of the outlet pipe at the output end of the heat exchanger The chilled water is sent to the chiller from the second valve of the three-way valve, and then sent to the air conditioning system after being further cooled by the chiller; since the chilled water sent to the chiller has been initially cooled by the refrigerant in the heat exchanger , Therefore, in this case, using the chiller to produce chilled water will reduce the energy consumption of the chiller. When the temperature monitored by the first temperature sensor collected by the controller is equal to or lower than the set value of the air conditioning system, the controller controls the first valve of the three-way valve to open. At this time, the chilled water output from the outlet pipe at the output end of the heat exchanger directly It is sent to the air conditioning system without going through the chiller to cool the chilled water, thus avoiding the energy consumption of the chiller.

As shown in Fig. 4, it is a cold water system provided by Embodiment 3 of the present invention.

The cold water system provided by the third embodiment of the present invention is based on the cold water system provided by the second embodiment, and further includes: a one-way valve, and the one-way valve is arranged on the inlet pipe of the chiller.

The purpose of setting the one-way valve is to prevent the output from the heat exchange output port from being mixed with the refrigerant when the temperature detected by the first temperature sensor is higher than the set value of the air conditioning system and the controller controls the second valve of the three-way valve to open. After heat exchange, the chilled water flows back into the heat exchanger.

In addition, in the embodiment of the present invention, the one-way valve is always kept closed.

As shown in FIG. 5 , it is a cold water system provided by Embodiment 4 of the present invention.

The cold water system provided by Embodiment 4 of the present invention is based on the cold water system provided by Embodiment 2, and further includes: a second temperature sensor, the second temperature sensor is arranged on the inlet pipe at the output end of the heat exchanger, and the second temperature sensor Used to monitor the temperature of chilled water in the inlet pipe at the output end of the heat exchanger;

The second temperature sensor is electrically connected to the controller, and is used for controlling the closing of the three-way valve and opening of the second valve, and closing the first valve of the three-way valve when the temperature monitored by the second temperature sensor is lower than the outdoor temperature.

The working process of the cold water system in this embodiment is as follows: if the temperature of the used high-temperature chilled water that comes out of the return pipe of the air conditioning system, that is, the outlet pipe that is monitored by the second temperature sensor collected by the controller, is lower than the outdoor temperature, Then the controller opens the second valve of the three-way valve and closes the first valve of the three-way valve. At this time, only the chiller is used for refrigeration.

Using the above-mentioned cold water system, the temperature of the used high-temperature chilled water that comes out of the return water pipe of the air-conditioning system, that is, the outlet pipe detected by the second temperature sensor collected by the controller, is lower than the outdoor temperature, and the controller opens the three-way valve The second valve of the three-way valve is closed, and the first outlet of the first valve of the three-way valve is closed. At this time, only the chiller is used for refrigeration.

In summary, using the cold water system provided by the present invention, according to the outdoor temperature and the temperature of the chilled water entering the air-conditioning system, chilled water can be produced by using a chiller combined with a cold recovery device; or only a cold recovery device can be used It is also possible to use chillers to produce chilled water; it can be seen that using the chilled water system provided by the present invention to produce chilled water no longer only utilizes chillers to produce chilled water, and even does not need to use chilled water in certain specific cases The unit produces chilled water. Therefore, adopting the cold water system provided by the present invention can reduce the energy consumption of the air conditioning system in the process of using the chiller to produce chilled water.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (7)

1. A cold water system, characterized in that, comprising: a heat exchanger, the input end of the heat exchanger is connected with a cold recovery device, and the output end of the heat exchanger is connected with a water chiller; A coil pipe and a fan unit for supplying air to the coil pipe are arranged in the cold recovery device, and the inlet and outlet of the coil pipe are communicated with the outlet pipe and the inlet pipe of the input end of the heat exchanger respectively. The inlet pipe of the coil is provided with a first circulation pump, and the first circulation pump is used to circulate the refrigerant in the coil; A three-way valve is arranged between the water outlet pipe of the chiller and the water outlet pipe at the output end of the heat exchanger; The first valve of the three-way valve is selectively communicated with the water outlet pipe of the chiller, the second valve of the three-way valve is selectively communicated with the water inlet pipe of the chiller, and the third valve of the three-way valve is The valve communicates with the water outlet pipe of the heat exchanger. 2. The system of claim 1, further comprising: a first temperature sensor and a controller; The first temperature sensor is arranged on the outlet pipe of the output end of the heat exchanger, and the first temperature sensor is used to monitor the temperature of the chilled water in the outlet pipe of the output end of the heat exchanger; The controller is electrically connected to the first temperature sensor and the three-way valve, and is used to control the second valve of the three-way valve when the temperature detected by the first temperature sensor is higher than a set value Opening: when the temperature detected by the first temperature sensor is equal to or lower than the set value, the first valve controlling the three-way valve is opened. 3. The system of claim 2, further comprising: a second temperature sensor; The second temperature sensor is arranged on the inlet pipe of the output end of the heat exchanger, and the second temperature sensor is used to monitor the temperature of the chilled water in the inlet pipe of the output end of the heat exchanger; The controller is also electrically connected to the second temperature sensor, and is used to control the second valve of the three-way valve to open when the temperature monitored by the second temperature sensor is higher than the outdoor temperature. 4. The system according to claim 2, characterized in that, the number of the fan units is one group; The controller is also electrically connected to the fan unit, and is used to lower the frequency of the fan unit when the temperature detected by the first temperature sensor is equal to or lower than the set value; When the temperature detected by the temperature sensor is higher than the set value, the frequency of the fan unit is increased. 5. The system according to claim 2, characterized in that, the number of the fan units is multiple groups; The controller is also electrically connected to the fan unit, and is used to shut down part of the fan unit when the temperature monitored by the first temperature sensor is equal to or lower than the set value; when the first temperature sensor monitors When the temperature reached is higher than the set value, increase the frequency of the currently turned on fan unit and/or turn on the currently turned off fan unit. 6. The system according to claim 2, further comprising: a damper and a damper actuator, the damper is arranged inside the fan unit, and the damper actuator is used to control the damper of the damper opening; The controller is also electrically connected to the air valve actuator, and is used for when the temperature monitored by the first temperature sensor is equal to or lower than the set value, and only one group of fans is running and its frequency reaches the minimum allowable When the frequency is running, the opening of the air valve is adjusted by the air valve actuator. 7. The system according to any one of claims 1-6, further comprising: a refrigerant expansion tank, the refrigerant expansion tank being in communication with the outlet pipe at the input end of the heat exchanger.