CN116399047A

CN116399047A - Water chilling unit control method and device, readable storage medium and water chilling unit

Info

Publication number: CN116399047A
Application number: CN202310446724.8A
Authority: CN
Inventors: 易勇; 杨圣; 楼钱杰
Original assignee: Zhejiang Dunan Electro Mechanical Technology Co Ltd
Current assignee: Zhejiang Dunan Electro Mechanical Technology Co Ltd
Priority date: 2020-03-24
Filing date: 2020-03-24
Publication date: 2023-07-07
Also published as: CN113446763A

Abstract

The application relates to a water chiller control method and device, a readable storage medium and a water chiller. Wherein, the cooling water set includes two at least compressors that the parallel arrangement, the method includes: acquiring working condition information of the current operation of the water chilling unit, wherein the working condition information comprises the outlet water temperature To of the evaporator and the current load value Qv of the operation of the water chilling unit; defining the number of compressors which are not operated in the water chilling unit as N, determining the difference value between a full load value Q of the water chilling unit and the current load value Qv under the condition that the outlet water temperature To of the evaporator is smaller than the difference between the target outlet water temperature T2 and the tolerance delta T, and judging whether the difference value is continuously larger than the load value (N+1) xq of the N+1 compressors after waiting time T3; if so, the shutdown of the compressor with the longest operation time in the current operation is controlled, and the number of the compressors which are not operated is n=n+1. Through the application, the problem of low energy efficiency of the cold water unit in the related technology is solved, and the energy efficiency of the cold water unit is improved.

Description

Water chilling unit control method and device, readable storage medium and water chilling unit

The application is aimed at the application number: 202010212198.5 (the name of the invention is water chilling unit, control method of the water chilling unit and computer readable storage medium, the filing date is 24 days of 2020).

Technical Field

The present disclosure relates to the field of air conditioning technologies, and in particular, to a method and an apparatus for controlling a water chiller, a readable storage medium, and a water chiller.

Background

With the development of refrigeration technology, the requirements of people on the water chilling unit are gradually changed from pursuing full-load value energy efficiency to pursuing comprehensive partial-load value energy efficiency. In a conventional chiller vapor compression refrigeration cycle system, for a chiller with more than one compressor, it is common that one compressor corresponds to one refrigeration system, and each refrigeration system is independent of the other refrigeration system. Because the operation of the compressors is generally higher as the compressor approaches to the full-load working condition, under the condition of larger load shedding amplitude of the unit, the refrigeration system corresponding to the closed compressor is also correspondingly closed while one or more compressors are closed, and the other compressors and the refrigeration system are kept to be operated at high efficiency under the working condition of approaching to the full load.

Therefore, based on the control method of the water chilling unit in the traditional technology, the energy efficiency balance of each compressor and the refrigerating system of the water chilling unit is difficult to achieve, so that the overall energy efficiency of the water chilling unit is low.

Disclosure of Invention

The embodiment of the application provides a water chiller control method, a device, a readable storage medium and a water chiller, which are used for at least solving the problem of low overall energy efficiency of the water chiller in the related technology.

In a first aspect, an embodiment of the present application provides a control method of a water chiller, where the water chiller includes at least two compressors arranged in parallel, and the method includes:

acquiring working condition information of the current operation of the water chilling unit, wherein the working condition information comprises the outlet water temperature To of the evaporator and the current load value Qv of the operation of the water chilling unit;

defining the number of compressors which are not operated in the water chilling unit as N, determining the difference value between a full load value Q of the water chilling unit and the current load value Qv under the condition that the outlet water temperature To of the evaporator is smaller than the difference between the target outlet water temperature T2 and the tolerance delta T, and judging whether the difference value is continuously larger than the load value (N+1) xq of the N+1 compressors after waiting time T3;

if so, the shutdown of the compressor with the longest operation time in the current operation is controlled, and the number of the compressors which are not operated is n=n+1.

In one embodiment, the at least two compressors are respectively provided with a first regulating valve, and before determining the difference value between the full load value Q and the current load value Qv of the water chiller, the control method further includes:

judging whether the outlet water temperature To of the evaporator is greater than or equal To the suspension temperature T4 of the unit;

If not, controlling all the compressors to stop, closing the first regulating valves corresponding to the compressors, and setting the water chilling unit to be in a pause state.

In one embodiment, after controlling the shutdown of the compressor currently operating for the longest operating time, the control method further includes:

the method comprises the steps of controlling a first regulating valve corresponding to a stopped compressor with the longest running time to be closed, and judging whether a non-closed compressor exists or not;

if not, setting the water chilling unit to be in a pause state.

In one embodiment, after setting the water chiller to a suspended state, the control method further includes:

judging whether the outlet water temperature To of the evaporator is higher than the restarting temperature T1 of the compressor;

and if the evaporator water outlet temperature To is higher than the compressor restarting temperature T1, controlling the compressor To start.

In one embodiment, controlling the compressor start comprises:

and controlling the compressors to be started simultaneously, starting the first regulating valves corresponding to the compressors after the starting time of the compressors reaches t1, and setting the water chiller to be in a normal running state.

In one embodiment, controlling the compressor start comprises:

Controlling the compressors to start one by one, comparing the running time of the compressors, controlling the compressor with the shortest running time in the non-running compressors to start, and starting the first regulating valve corresponding to the compressor after the starting time of the compressor reaches t 1;

when the starting time of the compressor reaches T2, judging whether the difference value between the outlet water temperature To of the evaporator and the target outlet water temperature T2 is smaller than T3;

if not, and the cold water unit has the compressor which is not started currently, the compressor with the shortest running time in the compressor which is not started currently is controlled to be started.

In one embodiment, the water chiller further includes an economizer, the at least two compressors are connected with the economizer, a second regulating valve is further disposed on a pipeline connected with the evaporator, the working condition information further includes a liquid level height value H of the economizer, and the method further includes:

judging whether the liquid level height value H is lower than a lowest liquid level height value H1, if yes, adjusting the opening of the second regulating valve to increase the liquid level height value H, and if not, judging whether the liquid level height value H is higher than a highest liquid level height value Hh;

and if the liquid level height value H is higher than the highest liquid level height value Hh, adjusting the opening of the second regulating valve to reduce the liquid level height value H, and closing all the first regulating valves.

In a second aspect, an embodiment of the present application provides a control device for a water chiller, where the water chiller includes at least two compressors arranged in parallel, and the device includes:

the information acquisition module is used for acquiring working condition information of the current operation of the water chilling unit, wherein the working condition information comprises the outlet water temperature To of the evaporator and the current load value Qv of the operation of the water chilling unit;

the judging module is used for defining the number of the compressors which are not operated in the water chilling unit as N, determining the difference value between the full load value Q of the water chilling unit and the current load value Qv under the condition that the outlet water temperature To of the evaporator is smaller than the difference between the target outlet water temperature T2 and the tolerance delta T, and judging whether the difference value is continuously larger than the load value Q of the n+1 compressors after the waiting time T3;

and the control module is used for controlling the shutdown of the compressor with the longest operation time in the current operation if the difference value is continuously larger than the load value (N+1) x q of the N+1 compressors, and the number of the compressors which are not operated is N=N+1.

In a third aspect, an embodiment of the present application provides a readable storage medium having stored thereon a computer program, which when executed by a processor, implements the steps of the chiller control method of any one of the first aspects above.

In a fourth aspect, the embodiment of the application provides a water chiller, the water chiller includes two at least compressors, an economizer, an evaporator and a condenser that are parallelly connected, wherein, the air supply ports of two at least compressors are respectively connected with the air outlet of the economizer, the liquid outlet of the condenser is connected with the inlet of the economizer, the inlet of the evaporator is connected with the liquid outlet of the economizer, the air supply ports of two at least compressors are respectively and correspondingly provided with a first regulating valve on the pipeline connected with the air outlet of the economizer, the liquid outlet of the condenser is provided with a first throttling device on the pipeline connected with the inlet of the economizer, and the inlet of the evaporator is provided with a second throttling device on the pipeline connected with the liquid outlet of the economizer, and the water chiller is used for realizing the steps of the water chiller control method according to any one of claims 1 to 8.

In one embodiment, the outlet of the first throttling device is also connected with the inlet of the evaporator, a third regulating valve is arranged on a pipeline for connecting the outlet of the first throttling device with the inlet of the evaporator, and the third regulating valve is arranged in parallel with the economizer;

And a second regulating valve is further arranged on a pipeline connected with the inlet of the evaporator and the liquid outlet of the economizer.

Compared with the prior art, the control method and device of the water chilling unit, the readable storage medium and the water chilling unit provided by the embodiment of the application are capable of controlling the compressor with the longest running time to be off-load if the N+1 compressors can still meet the refrigeration requirement after off-load under the condition that the unit is required to be off-load. And because the compressors are connected in parallel and share the same refrigerating system, the reduction of load of one or a plurality of compressors does not lead to the reduction of energy efficiency caused by the stop of part of refrigerating systems. On the premise of not influencing the integral refrigeration requirement of the water chilling unit, the water chilling unit control method provided by the embodiment of the application can dynamically adjust the operation and load-shedding compressors according to the operation time of the compressors, so that the energy efficiency balance control of the water chilling unit is realized, and the overall energy efficiency of the water chilling unit is improved, and meanwhile, the service lives of the compressors and the water chilling unit are prolonged.

The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below to provide a more thorough understanding of the other features, objects, and advantages of the application.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:

FIG. 1 is a schematic structural view of a water chiller according to an embodiment of the present application;

FIG. 2 is a flow chart of a water chiller control method according to an embodiment of the present application;

FIG. 3 is a flow chart of a chiller start-up control according to an embodiment of the present application;

FIG. 4 is a control flow diagram of a compressor unit simultaneous start of a chiller according to an embodiment of the present application;

FIG. 5 is a control flow diagram of a gradual start-up of a compressor unit of a chiller according to an embodiment of the present application;

FIG. 6 is a control flow diagram of the make-up pressure according to an embodiment of the present application;

FIG. 7 is a control flow diagram of an economizer level in accordance with an embodiment of the present application;

fig. 8 is a control flow diagram for load shedding of a chiller according to an embodiment of the present application.

Description of the drawings:

01. an evaporator; 02. a compressor unit; 03. a condenser; 04. a first throttle device; 05. an economizer; 06. a second throttle device; 07. a first regulating valve; 08. the compressor air supplementing pressure detection device; 09. a second regulating valve; 10. a third regulating valve; 011. an evaporator inlet; 012. an evaporator air outlet; 013. an evaporation pressure detection device; 014. an evaporator outlet water temperature detection device; 015. an evaporator water inlet temperature detection device; 021. a compressor inlet; 022. a compressor discharge port; 023. a compressor air supply port; 031. a condenser air inlet; 032. a condenser liquid outlet; 033. condensing pressure detection means; 041. a first throttle inlet; 042. a first restriction outlet; 051. an economizer inlet; 052. an economizer outlet; 053. an economizer outlet; 054. an economizer level monitoring device; 061. a second throttling device inlet; 062. a second restriction outlet; 100. a water chiller; 0102. a compressor suction pipe group; 0203. a compressor discharge stack; 0304. a condenser outlet pipe; 0401. an economizer bypass line; 0405. a first liquid supply pipe; 0502. a compressor air supplementing pipe group; 0506. an economizer outlet pipe; 0601. and a second liquid supply pipe.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described and illustrated below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden on the person of ordinary skill in the art based on the embodiments provided herein, are intended to be within the scope of the present application.

It is apparent that the drawings in the following description are only some examples or embodiments of the present application, and it is possible for those of ordinary skill in the art to apply the present application to other similar situations according to these drawings without inventive effort. Moreover, it should be appreciated that while such a development effort might be complex and lengthy, it would nevertheless be a routine undertaking of design, fabrication, or manufacture for those of ordinary skill having the benefit of this disclosure, and thus should not be construed as having the benefit of this disclosure.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is to be expressly and implicitly understood by those of ordinary skill in the art that the embodiments described herein can be combined with other embodiments without conflict.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs, including by one of ordinary skill in the art. Reference to "a," "an," "the," and similar terms herein do not denote a limitation of quantity, but rather denote the singular or plural. The terms "comprising," "including," and any variations thereof, as used herein, are intended to cover a non-exclusive inclusion; for example, a process, method, system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to only those steps or elements but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. The terms "connected," "coupled," and the like in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality" as used herein refers to two or more. "and/or" describes an association relationship of an association object, meaning that there may be three relationships, e.g., "a and/or B" may mean: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship. The terms "first," "second," "third," and the like, as used herein, are merely distinguishing between similar objects and not representing a particular ordering of objects.

The water chiller, the control method of the water chiller and the computer readable storage medium related to the application can be applied to the technical field of household air conditioners and also can be applied to the field of industrial refrigeration.

The embodiment provides a water chiller, which adopts a refrigeration cycle in the form of a two-stage throttling and economizer. Fig. 1 is a schematic structural diagram of a water chiller according to an embodiment of the present application, as shown in fig. 1, the water chiller 100 includes: an evaporator 01, a compressor block 02, a condenser 03, a first throttle device 04, an economizer 05 and a second throttle device 06.

The evaporator 01 comprises an inlet 011 and an air outlet 012, the compressor unit 02 comprises a plurality of compressors arranged in parallel, each compressor comprises an inlet 021, an air outlet 022 and an air supplementing port 023, the condenser 03 comprises an air inlet 031 and a liquid outlet 032, and the economizer 05 comprises an inlet 051, an air outlet 052 and a liquid outlet 053.

The gas outlet 012 of the evaporator 01 is communicated with the inlets 021 of a plurality of compressors in parallel, the gas outlet 022 of the compressors is communicated with the gas inlet 031 of the condenser 03 in parallel, the gas supplementing ports 023 of the compressors are communicated with the gas outlet 052 of the economizer 05 in parallel, the liquid outlet 032 of the condenser 03 is communicated with the inlet 051 of the economizer 05, the liquid outlet 053 of the economizer 05 is communicated with the inlet 011 of the evaporator 01, the first throttling device 04 is arranged on a pipeline between the liquid outlet 032 of the condenser 03 and the inlet 051 of the economizer 05, and the second throttling device 06 is arranged on a pipeline between the liquid outlet 053 of the economizer 05 and the inlet 011 of the evaporator 01.

The water chiller 100 of the present embodiment further includes: a plurality of first regulating valves 07 and a controller. Wherein, a plurality of first regulating valves 07 are arranged on the parallel branch of the air supplementing ports 023 of a plurality of compressors and the air outlet 052 of the economizer 05 in a one-to-one correspondence manner; and the controller is used for controlling the opening degrees of the plurality of first regulating valves 07 according to the operation condition information of the water chilling unit 100.

The evaporator 01 may be a falling film evaporator, a flooded evaporator or a dry evaporator, and the evaporator 01 is used to provide heat for the low-temperature low-pressure refrigerant liquid to generate low-temperature low-pressure refrigerant gas.

The compressor unit 02 has at least two compressors, and the compressor unit 02 may be a centrifugal compressor or a screw compressor, and the compressor unit 02 is configured to compress a low-temperature low-pressure refrigerant gas to generate a high-temperature high-pressure refrigerant gas.

The condenser 03 is used to condense the high-temperature and high-pressure refrigerant gas from the compressor unit 02 into a refrigerant liquid.

The first throttle device 04 and the second throttle device 06 may be electronic expansion valves, throttle plates, throttle valves or thermal expansion valves, respectively. The first throttling device 04 and the second throttling device 06 are used for reducing the pressure of the refrigerant liquid to generate a refrigerant gas-liquid mixture.

A condenser liquid outlet pipe 0304 and a first liquid supply pipe 0405 are arranged between a liquid outlet 032 of the condenser 03 and an inlet 051 of the economizer 05, an inlet 041 of the first throttling device 04 is communicated with the condenser liquid outlet 032 through the condenser liquid outlet pipe 0304, and an outlet 042 of the first throttling device 04 is communicated with the inlet 051 of the economizer 05 through the first liquid supply pipe 0405. The refrigerant liquid from the condenser 03 enters the first throttling device 04 through the condenser liquid outlet pipe 0304, is throttled and depressurized, becomes a refrigerant gas-liquid mixture, and enters the economizer 05 through the first liquid supply pipe 0405.

The economizer 05 can adopt a vertical economizer or a horizontal economizer, the economizer 05 is used for carrying out gas-liquid separation on the refrigerant gas-liquid mixture, the separated gas is discharged from the gas outlet 052, and the liquid is discharged from the liquid outlet 053.

An economizer liquid outlet pipe 0506 and a second liquid supply pipe 0601 are arranged between the liquid outlet port 053 of the economizer 05 and the evaporator 01, an inlet 061 of the second throttling device 06 is communicated with the liquid outlet port 053 of the economizer 05 through the economizer liquid outlet pipe 0506, and an outlet 062 of the second throttling device 06 is communicated with an inlet 011 of the evaporator 01 through the second liquid supply pipe 0601. The refrigerant liquid separated from the economizer 05 enters the second throttling device 06 through the economizer outlet pipe 0506, is throttled and depressurized, and enters the evaporator 01 through the second liquid supply pipe 0601.

A compressor air-supplementing pipe set 0502 (that is, a parallel branch of air-supplementing ports 023 of the plurality of compressors and air-supplementing ports 052 of the economizer 05) is arranged between the compressor set 02 and the economizer 05, wherein the number of the air-supplementing pipes is identical to that of the compressors in the compressor set 02, and each air-supplementing pipe is used for communicating the air-supplementing port 052 of the economizer 05 with the air-supplementing ports 023 of each compressor in the compressor set 02. The refrigerant gas separated in the economizer 05 is introduced into each compressor of the compressor unit 02 through the gas supply pipe in the gas supply pipe unit 0502. The first regulating valve 07 is arranged on each air supplementing pipe of the compressor air supplementing pipe set 0502 and is used for regulating the pressure of each compressor of the compressor set 02.

In some of these embodiments, the chiller 100 further includes: a second regulating valve 09, the second regulating valve 09 being arranged on the line between the outlet of the first restriction 04 and the inlet of the evaporator 01. The controller is further configured to control the opening of the second regulating valve 09 according to the operation condition information of the water chiller 100.

Since the inlet 051 and the outlet 053 of the economizer and the second throttling device 06 are sequentially connected in series on the pipeline between the outlet of the first throttling device 04 and the inlet of the evaporator 01, the second regulating valve 09 can be arranged on the second liquid supply pipe 0601, the economizer liquid outlet pipe 0506 or the first liquid supply pipe 0405 for regulating the liquid level height value in the economizer 05.

During operation of the chiller 100, the pressure of the compressor unit 02 and the level of the economizer 05 may fluctuate as the operating conditions of the unit change, particularly during loading and unloading of the unit. In order to improve the refrigerating capacity and energy efficiency of the water chiller 100 under the full working condition, in this embodiment, a second adjusting valve 09, a first adjusting valve 07 and a controller are provided, where the controller can obtain a detection signal of the water chiller 100, and the detection signal indicates the operation working condition information of the water chiller. The controller obtains the operation condition information of the water chiller 100 according to the detection signal, and sends out control signals to the second regulating valve 09 and/or the first regulating valves 07 so as to regulate the opening degree of the second regulating valve 09 and/or the first regulating valves 07. Through the control to the aperture of first governing valve 07, can make the air compensating pressure value of compressor be in the presupposed pressure range all the time, promote the pneumatic efficiency of compressor, and then promoted refrigerating output and the energy efficiency of unit under full operating mode. Under full working conditions, through the control of the opening degree of the second regulating valve 09, or through the control of the opening degree of the first regulating valve 07 and the second regulating valve 09, the liquid level height value of the economizer is controlled, so that the risk of air supplementing and liquid carrying caused by overhigh liquid level height value of the economizer is avoided, the air leakage of the second throttling device caused by overlow liquid level height value of the economizer is also avoided, and the reliability and the energy efficiency of the unit are improved.

In some of these embodiments, chiller 100 also includes a compressor suction line set 0102 and a compressor discharge line set 0203. Wherein each suction pipe in the compressor suction pipe group 0102 communicates with the air outlet 012 of the evaporator 01 and the inlet 021 of the compressor, and each discharge pipe in the compressor discharge pipe group 0203 communicates with the air outlet 022 of each compressor and the air inlet 031 of the condenser 03. The low-temperature low-pressure refrigerant liquid absorbs heat in the evaporator 01 to evaporate into a low-temperature low-pressure refrigerant gas, and is sucked into the compressor stack 02 through the respective suction pipes of the compressor suction pipe group 0102. After entering the compressor group 02, the refrigerant gas is compressed into a high-temperature high-pressure refrigerant gas, and then enters the condenser 03 through each exhaust pipe of the compressor exhaust pipe group 0203, and is condensed into a refrigerant liquid in the condenser 03.

The number of intake pipes included in compressor intake pipe group 0102 and the number of exhaust pipes included in compressor exhaust pipe group 0203 are equal to the number of compressors. All the air suction pipes of the compressor are arranged in parallel, the air suction pipe group 0102 of the compressor is communicated with the air outlet 012 of the evaporator 01, and the communication mode can be that a plurality of air outlets are arranged on the evaporator 01 and are respectively communicated with each air suction pipe, or one air outlet is led out and is divided into a plurality of air suction pipes. All the compressor exhaust pipes are also arranged in parallel, and the compressor exhaust pipe group 0203 is communicated with the air inlet 031 of the condenser 03, wherein the communication mode can be that a plurality of air inlets are arranged in the condenser 03 and are respectively communicated with each exhaust pipe, or a plurality of exhaust pipes are gathered together and then communicated with the air inlet 031.

In the embodiment, the refrigerating capacity and the energy efficiency of the water chilling unit can be improved in the form of a double-stage throttling economizer. The unit is designed to be in a form that a plurality of compressors share the heat exchanger and the economizer, so that the heat exchanger and the economizer can be effectively utilized in the running state that the compressors are stopped, and the cold quantity and the energy efficiency of the unit under partial load values are improved.

In some of these embodiments, the outlet 042 of the first throttle device 04 is also in communication with the inlet 011 of the evaporator 01, and the chiller 100 further includes a third regulator valve 10, the third regulator valve 10 being disposed in the line between the first throttle device 04 and the inlet 011 of the evaporator 01.

In this embodiment, the outlet of the first throttling device 04 and the evaporator inlet 011 can be directly communicated, and a third regulating valve 10 is disposed on a pipeline between the first throttling device 04 and the evaporator inlet 011, during the operation of the chiller 100, the controller can selectively close all the second regulating valves 09 and the first regulating valves 07 according to the operation condition of the chiller 100, so as to shield the economizer 05, and realize the normal operation of the chiller 100 through the third regulating valve 10.

In some of these embodiments, an economizer bypass line 0401 is provided between the first throttle device 04 and the inlet 011 of the evaporator 01, the economizer bypass line 0401 being provided in parallel with the outlet 053 of the economizer 05, the economizer bypass line 0401 being provided with a third regulating valve 10.

In this embodiment, the economizer bypass line 0401 is parallel to the economizer outlet pipe 0506, the third regulating valve 10 is disposed on the economizer bypass line 0401, and during the operation of the chiller 100, the controller can selectively close all the second regulating valves 09 and the first regulating valves 07 according to the operation condition of the chiller 100, so as to shield the economizer 05, and realize the normal operation of the chiller 100 through the third regulating valve 10.

In some embodiments, the chiller 100 further includes an operating condition information detection device electrically coupled to the controller. The operation condition information detection device is used for collecting detection signals used for representing operation condition information of the water chilling unit 100 in the operation process, and sending the collected detection signals to the controller, and the controller is used for processing the detection signals to control the operation of the water chilling unit 100.

In some embodiments, the operating condition information detection means comprises at least one of: the compressor make-up pressure detection device 08, the evaporation pressure detection device 013, the evaporator outlet water temperature detection device 014, the evaporator inlet water temperature detection device 015, the condensation pressure detection device 033 and the economizer liquid level monitoring device 054.

In this embodiment, the compressor air make-up pressure detecting device 08 is mounted on the compressor air make-up tube set 0502 and is close to the air make-up port 023 of the compressor for collecting the air make-up pressure Pb. The evaporation pressure detection device 013, the evaporator outlet water temperature detection device 014 and the evaporator inlet water temperature detection device 015 are installed on the evaporator 01 and are respectively used for collecting an evaporation pressure value Pc, an evaporator outlet water temperature value To and an evaporator inlet water temperature value Ti. The condensation pressure detecting device 033 is mounted on the condenser 03 and is used for collecting the condensation pressure value Pe. An economizer level monitoring device 054 is mounted on the economizer 05 for acquiring an economizer level height value H.

In some of these embodiments, the compressor string 02 is configured to provide an operating parameter for each compressor and to control the operation of each compressor in response to a signal from the controller to each compressor. The second regulator valve 09 and the first regulator valve 07 are provided so as to be able to control the opening degree of the regulator valve in response to a signal from the controller. The controller is configured to collect detection signals of the detection devices, and send control signals to the compressors and the regulating valves in response to the collected detection signals or the calculated parameters to control the operation of the compressors and the opening degree of the regulating valves.

The embodiment also provides a control method of the water chilling unit, which is applied to the water chilling unit in the embodiment. Fig. 2 is a flowchart of a control method of a water chiller according to an embodiment of the present application, as shown in fig. 2, the flowchart includes the following steps:

step S201, a controller acquires operation condition information of a water chilling unit;

in step S202, the controller controls the opening degrees of the plurality of first regulating valves according to the operating condition information.

Through the steps, the controller controls the opening degrees of the first regulating valves according to the operation condition information of the water chilling unit, so that the control of the air supplementing pressure value of the air supplementing port of the compressor is realized, the pneumatic efficiency of the compressor is improved, and the refrigerating capacity and the energy efficiency of the water chilling unit under all conditions can be improved.

In some of these embodiments, the operating condition information of the chiller includes a load value of the chiller, a start-stop status of the compressor, an intermediate pressure value of the compressor, a liquid level height value of the economizer, and the like. The operation condition information can be acquired by the operation condition information detection device, and can also be calculated according to the data acquired by the operation condition information detection device. For example, an evaporation pressure value of the evaporator may be collected, a condensation pressure value of the condenser may be collected, and an intermediate pressure value of the compressor may be calculated from the collected evaporation pressure value and condensation pressure value. For example, the outlet water temperature value of the evaporator may be collected, the inlet water temperature value of the evaporator may be collected, and the load value of the chiller may be calculated according to the collected outlet water temperature value and inlet water temperature value. For example, the air supply pressure value of the air supply port of the compressor may be obtained by the air supply pressure detection device of the compressor. For example, the level value of the economizer may be monitored by an economizer level value detection device.

In the present embodiment, the controller is configured to be capable of acquiring detection signals provided by the compressor barometric pressure detection device 08, the evaporation pressure detection device 013, the evaporator outlet water temperature detection device 014, the evaporator inlet water temperature detection device 015, the condensation pressure detection device 033 and the economizer liquid level monitoring device 054, and calculating an intermediate pressure value Pm of the compressor according to the acquired evaporation pressure value Pc and condensation pressure value Pe; and calculating according To the acquired water inlet and outlet temperature values Ti and To of the evaporator To obtain the current load value Qv of the water chilling unit. The controller may be further configured to send control signals to each of the compressors and the regulating valves to control the operation of the compressors and the opening degree of the regulating valves in response to the collected detection signals or the calculated parameters.

In some of these embodiments, the water chiller further comprises: and the second regulating valve is arranged on a pipeline between the outlet of the first throttling device and the inlet of the evaporator. The control method of the water chilling unit further comprises the following steps: after the controller obtains the operation condition information of the water chiller, the controller controls the opening of the second regulating valve according to the operation condition information in step S201.

In some embodiments, the control method of the water chiller further includes: after the controller obtains the operation condition information of the water chiller, the controller controls the water chiller to reduce load according to the operation condition information in step S201.

The control method of the water chilling unit under different operation condition information will be described below.

1. Power-on starting of water chilling unit

In some embodiments, when the water chiller is powered on, the controller may control the opening degrees of the plurality of first adjusting valves according to the operating condition information in the following manner: the method comprises the steps of controlling a plurality of first regulating valves to be closed, and detecting the start-stop states of a plurality of compressors in a water chilling unit; and when the operation state of the second compressor is changed into the stop state, the first regulating valve on the parallel branch where the air supplementing port of the second compressor is controlled to be closed.

Fig. 3 is a flowchart of a water chiller start-up control according to an embodiment of the present application, as shown in fig. 3, the flowchart includes the following steps:

step S301, a unit is in a stop state;

step S302, powering up a unit;

step S303, the controller detects whether the first regulating valve is closed, and if it is detected that the first regulating valve is not closed, step S304 is executed, and if it is detected that the first regulating valve is closed, step S305 is executed;

Step S304, closing a first regulating valve;

step S305, the controller receives a startup signal;

step S306, the unit is in a pause state;

step S307, the controller determines whether the evaporator outlet water temperature To is higher than the compressor restart temperature T1, and executes step S308 if it is determined that the evaporator outlet water temperature To is higher than the compressor restart temperature T1, and returns To step S306 if it is determined that the evaporator outlet water temperature To is not higher than the compressor restart temperature T1;

in step S308, the controller controls the start-up and loading of the compressor package 02.

Through the steps, after the unit is electrified, the controller detects the state of the first regulating valve and keeps the state of the first regulating valve closed; when the start button is pressed on the compressor unit or the outlet water temperature value To of the evaporator is higher than the restarting temperature T1 of the compressor, the controller controls the compressor unit To start and load. The controller controls the start of the compressor group 02, and may start all compressors simultaneously or start compressors one by one.

Fig. 4 is a control flow chart of the compressor unit simultaneous start of the water chiller according to an embodiment of the present application, as shown in fig. 4, the flow includes the following steps:

step S309, all compressors are started and loaded simultaneously;

Step S310, the starting time of the compressor reaches t1;

step S311, opening the first regulating valve S311;

step S312, the unit operates normally.

Through the steps, the controller controls all compressors of the compressor unit 02 to be started simultaneously, and after the starting time of the compressors reaches t1, all first regulating valves are started.

Fig. 5 is a control flow chart of gradual start of a water chiller according to an embodiment of the present application, as shown in fig. 5, the flow includes the following steps:

step S310, the starting time of the compressor reaches t1;

step S312, the unit normally operates;

step S313, starting and loading the compressor with the shortest running time in the non-running compressor;

step S314, opening the corresponding first regulating valve;

step S315, the starting time of the compressor reaches t2;

step S316, the controller judges whether the difference between the evaporator outlet water temperature value To and the target outlet water temperature value T2 is smaller than T3, executes step S312 if it is judged that the difference between the evaporator outlet water temperature value To and the target outlet water temperature value T2 is smaller than T3, and returns To step S317 if it is judged that the difference between the evaporator outlet water temperature value To and the target outlet water temperature value T2 is not smaller than T3;

in step S317, the controller determines whether or not there is an un-started compressor, and if it is determined that there is an un-started compressor, it executes step S313, and if it is determined that there is no un-started compressor, it executes step S312.

Through the steps, when the compressors are started one by one, the operation time of all the compressors is compared, the compressor with the shortest operation time is started first, and the corresponding first regulating valve is started after the start time of the compressor reaches t 1. After the starting time of the compressor reaches T2, if the difference between the outlet water temperature value To of the evaporator and the target outlet water temperature value T2 is smaller than T3, the compressor is continuously loaded, and the unit normally operates. If the difference between the outlet water temperature value T of the evaporator and the target outlet water temperature value T2 is larger than T3, starting the compressor with the shortest running time in all the non-running compressors, and repeating the operation after the starting of the first compressor until the unit normally runs.

2. Compressor air supplementing pressure control in running process of water chilling unit

In some embodiments, during the running process of the water chiller, the controller may control the opening degrees of the plurality of first adjusting valves according to the running condition information in the following manner: detecting a pressure value of a gas supplementing port of a third compressor in the plurality of compressors under the condition that the third compressor is in an operating state; controlling a first regulating valve on a parallel branch where the air supplementing port of the third compressor is positioned to increase the opening degree under the condition that the air supplementing pressure value of the air supplementing port of the third compressor is smaller than a first preset pressure value; controlling a first regulating valve on a parallel branch where the air supplementing port of the third compressor is positioned to reduce the opening degree under the condition that the air supplementing pressure value of the air supplementing port of the third compressor is larger than a second preset pressure value; the first preset pressure value is smaller than the intermediate pressure value of the third compressor, and the second preset pressure value is larger than the intermediate pressure value of the third compressor. The boost pressure value of each compressor in the compressor train is controlled in the manner described above.

Fig. 6 is a control flow chart of the compressor air make-up pressure according to an embodiment of the present application, as shown in fig. 6, the flow including the steps of:

step S312, the unit normally operates;

step S318, the controller determines whether the air supply pressure Pb is smaller than the difference between the intermediate pressure Pm and the tolerance Δp, and if it is determined that the air supply pressure Pb is smaller than the difference between the intermediate pressure Pm and the tolerance Δp, step S319 is executed, and if it is determined that the air supply pressure Pb is not smaller than the difference between the intermediate pressure Pm and the tolerance Δp, step S320 is executed;

step S319, the opening of the corresponding first regulating valve is increased;

step S320, the controller determines whether the air-supplementing pressure Pb is greater than the sum of the intermediate pressure Pm and the tolerance Δp, and if it is determined that the air-supplementing pressure Pb is greater than the sum of the intermediate pressure Pm and the tolerance Δp, step S321 is executed, and if it is determined that the air-supplementing pressure Pb is not greater than the sum of the intermediate pressure Pm and the tolerance Δp, the step S318 is returned to;

in step S321, the opening of the corresponding first regulating valve is reduced.

Through the above steps, during the running process of the water chiller, if the compressor air supplementing pressure detecting device 08 detects that the air supplementing pressure value Pb is smaller than the difference between the intermediate pressure value Pm and the tolerance Δp, the controller controls the first regulating valve 07 of the corresponding compressor to increase the opening; if the compressor barometric pressure detection means 08 detects that the barometric pressure value Pb is greater than the sum of Pm and Δp, the controller controls the first regulator valve 07 of the corresponding compressor to decrease the opening. The value of the tolerance Δp described above may be set as desired, and its function is to avoid frequent actuation of the first regulator valve 07. The intermediate pressure value may be calculated by acquiring the evaporation pressure value of the evaporator, acquiring the condensation pressure value of the condenser, and calculating the intermediate pressure value of the compressor according to the acquired evaporation pressure value and condensation pressure value.

In the running process of the water chilling unit, the first regulating valve of the compressor is controlled, so that the air supplementing pressure value of the compressor is always about the middle pressure value of the compressor, the pneumatic efficiency of the compressor is improved, and the refrigerating capacity and the energy efficiency of the unit under all working conditions are improved.

3. Control of liquid level of economizer in running process of water chilling unit

In some embodiments, the controller controls the opening of the second regulating valve according to the operating condition information, including: detecting the liquid level height value of the economizer under the condition that the water chilling unit is in an operating state; controlling the opening degree of the second regulating valve to increase the liquid level height value of the economizer under the condition that the liquid level height value of the economizer is smaller than the first height value; and controlling the opening degree of the second regulating valve to reduce the liquid level height value of the economizer under the condition that the liquid level height value of the economizer is larger than the second height value. The controller controls the opening degree of the plurality of first regulating valves according to the operation condition information further comprises: and controlling the first regulating valves to be closed when the liquid level height value of the economizer is larger than the second height value.

In the running process of the water chilling unit, the liquid level height value in the economizer 05 can fluctuate along with different running states, and particularly in the loading and unloading processes of the unit, the fluctuation of the liquid level height value of the economizer is large. FIG. 7 is a control flow diagram of the level of the economizer according to an embodiment of the present application, as shown in FIG. 7, including the steps of:

Step S312, the unit normally operates;

step S322, the controller judges whether the liquid level height value H in the economizer is lower than the lowest liquid level height value Hl, and if the liquid level height value H in the economizer is judged to be lower than the lowest liquid level height value Hl, step S323 is executed, and if the liquid level height value H in the economizer is judged to be lower than the lowest liquid level height value Hl; in the case that the liquid level height value H in the economizer is not lower than the minimum liquid level height value Hl, step S324 is performed;

step S323, adjusting the opening of the second regulating valve;

step S324, the controller determines whether the liquid level H in the economizer is higher than the highest liquid level Hh, executes step S325 if it is determined that the liquid level H in the economizer is higher than the highest liquid level Hh, and returns to step S322 if it is determined that the liquid level H in the economizer is not higher than the highest liquid level Hh;

and step S325, adjusting the opening degree of the second regulating valve and closing all the first regulating valves.

Through the above steps, when the economizer liquid level monitoring device 054 detects that the liquid level height value H in the economizer 05 is lower than the lowest liquid level height value Hl, the controller controls the second regulating valve 09 to adjust the opening degree, so that the economizer liquid level height value rises; when the economizer liquid level monitoring device 054 detects that the liquid level height value H in the economizer 05 is higher than the highest liquid level height value Hh, the controller controls the first regulating valves 07 of all the compressors to be closed, and controls the second regulating valve 09 to adjust the opening degree, so that the economizer liquid level height value is reduced.

According to the embodiment, the liquid level height value of the economizer is controlled under the full working condition, so that the risk of air supplementing and liquid carrying caused by overhigh liquid level height value of the economizer is avoided, the air leakage of the secondary throttling device caused by overlow liquid level height value of the economizer is avoided, and the reliability of the unit and the energy efficiency of the unit are improved.

4. Load shedding control in running process of water chilling unit

In some embodiments, during the load shedding process of the water chiller, the full load value of the water chiller is taken as a reference, and each time the full load value of one compressor is controlled to be shedding by the water chiller, the fourth compressor in the water chiller is controlled to be switched from the running state to the stop state, and the first regulating valve on the parallel branch where the air supply port of the fourth compressor is located is controlled to be closed.

During the running process of the water chilling unit, the load shedding of the unit can be controlled according To the current load Qv and the water outlet temperature To. Fig. 8 is a control flow chart of load shedding of a water chiller according to an embodiment of the present application, as shown in fig. 8, the flow includes the following steps:

step S304, all the first regulating valves are closed;

step S326, the unit is normally operated, and the number of the unoperated compressors is N;

Step S327, the controller determines whether the outlet water temperature To is less than the difference between the target outlet water temperature T2 and the tolerance Δt, and if it is determined that the outlet water temperature To is less than the difference between the target outlet water temperature T2 and the tolerance Δt, step S328 is executed, and if it is determined that the outlet water temperature To is not less than the difference between the target outlet water temperature T2 and the tolerance Δt, step S327 is returned To;

step S328, all compressors are unloaded;

step S329, the controller determines whether the evaporator outlet water temperature To is greater than or equal To the suspension temperature T4 of the unit, performs step S330 if it is determined that the evaporator outlet water temperature To is greater than or equal To the suspension temperature T4 of the unit, and performs step S338 if it is determined that the evaporator outlet water temperature To is not greater than or equal To the suspension temperature T4 of the unit;

step S330, the controller judges whether the difference between the unit full load Q and the current load Qv is larger than the load Q of the single compressor, if it is judged that the difference between the unit full load Q and the current load Qv is larger than the load Q of the single compressor, the central step S331 returns to step S327 if it is judged that the difference between the unit full load Q and the current load Qv is not larger than the load Q of the single compressor

Step S331, waiting time t3;

Step S332, stopping the compressor with longest operation time in the non-operated compressor;

step S333, the controller determines whether the corresponding first regulating valve is closed, and if it is determined that the corresponding first regulating valve is closed, step S334 is executed, and if it is determined that the corresponding first regulating valve is not closed, step S335 is executed;

step S334, the number of non-operated compressors n=n+1;

step S335, closing the corresponding first regulating valve;

step S336, the controller determines whether there is an un-closed compressor, and if it is determined that there is an un-closed compressor, the controller proceeds to step S337, and if it is determined that there is no un-closed compressor, the controller returns to step S339;

step S337, loading all the non-closed compressors, and returning to step S327;

step S338, all compressors are closed;

step S339, the unit enters a pause state.

Through the steps, when the water outlet temperature To is smaller than the difference between the target water outlet temperature T2 and the tolerance delta T, the unit starts To be unloaded. When the difference value between the full load Q of the unit and the current load Qv is larger than the load Q of a single compressor and the duration time is larger than t3, the controller compares the running time of all the compressors, so that the compressor with the longest running time stops running first, and the first regulating valve on the corresponding air supplementing pipeline of the compressor is closed; after that, when the difference value between the full load Q of the unit and the current load Qv of the unit is larger than the loads 2*q of the two compressors and the duration time is larger than t3, the controller compares the running time of all the compressors which are not stopped, stops the operation of the compressor with the longest running time in all the compressors which are not stopped, and closes the first regulating valve on the corresponding air supplementing pipeline of the compressor; according to the rule, the compressors and the corresponding first regulating valves thereof are closed one by one according to the load shedding condition of the unit until all the compressors and the first regulating valves are closed, and the unit enters a pause state; if the outlet water temperature To of the evaporator is reduced To the suspension temperature T4 of the unit in the process of closing the compressors one by one, the remaining compressors still running are all closed, the corresponding first regulating valves are all closed, and the unit enters a suspension state.

During the running process of the water chilling unit, the load shedding of the unit can be controlled only according To the outlet water temperature To, and only two steps S230 in the steps are changed into: the controller determines whether the outlet water temperature To is less than the compressor shutdown water temperature, either single or multiple. For example, when the outlet water temperature To is less than the difference between the target outlet water temperature T2 and the tolerance Δt, the unit starts To be unloaded. When the water outlet temperature To is smaller than the stop water temperature of a single compressor and the duration is longer than t3, the controller compares the running time of all the compressors, so that the compressor with the longest running time stops running first, and the first regulating valve on the corresponding air supplementing pipeline of the compressor is closed; after that, when the water outlet temperature To is smaller than the water outlet temperature of the two compressors and the duration time is longer than t3, the controller compares the running time of all the compressors which are not stopped, so that the compressor with the longest running time in all the compressors which are not stopped stops running, and the first regulating valve on the corresponding air supplementing pipeline of the compressor is closed; according to the rule, the compressors and the corresponding first regulating valves thereof are closed one by one according to the load shedding condition of the unit until all the compressors and the first regulating valves are closed, and the unit enters a pause state; if the outlet water temperature To of the evaporator is reduced To the suspension temperature T4 of the unit in the process of closing the compressors one by one, the remaining compressors still running are all closed, the corresponding first regulating valves are all closed, and the unit enters a suspension state.

In the unit load shedding process, one or more compressors are selected to be closed according to the load shedding amplitude, so that the compressors always keep high-efficiency operation, and the unit performance is improved.

5. Control of water chilling unit shielding economizer

In some of these embodiments, the economizer 05 is provided with an economizer bypass line 0401 in parallel, and the economizer bypass line 0401 is provided with a third regulator valve 10. In the running process of the unit, the controller can control all the first regulating valves 07 and the second regulating valves 09 to be closed according to the running condition of the water chilling unit, shield the economizer and realize the normal running of the unit through the third regulating valve 10.

In summary, according to the control method for the water chilling unit and the water chilling unit, the economizer, the evaporator and the condenser are shared by the compressors, so that the economizer, the evaporator and the condenser can be effectively utilized in the running process of the unit. And controlling the air supplementing pressure value of the compressor and the liquid level height value of the economizer according to the running condition of the water chilling unit, so that the refrigerating capacity and the energy efficiency of the unit are improved under the full running condition.

In addition, in combination with the control method of the water chiller in the above embodiment, the embodiment of the application may be implemented by providing a computer readable storage medium. The computer readable storage medium has stored thereon computer program instructions; the computer program instructions, when executed by the processor, implement the control method of any one of the water chiller in the above embodiments.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples merely represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the invention. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application is to be determined by the claims appended hereto.

Claims

1. The utility model provides a cooling water set control method which is characterized in that the cooling water set includes at least two compressors that connect in parallel, the method includes:

2. The control method of a water chiller according to claim 1 wherein the at least two compressors are respectively provided with a first regulating valve, and the control method further comprises, before determining the difference between the full load value Q of the water chiller and the current load value Qv:

3. The chiller control method of claim 2, wherein after controlling a shutdown of a compressor currently operating for a longest period of time, the control method further comprises:

if not, setting the water chilling unit to be in a pause state.

4. The water chiller control method of claim 3, wherein after setting the water chiller to a suspended state, the control method further comprises:

5. The chiller control method of claim 4, wherein controlling the compressor start comprises:

6. The chiller control method of claim 4, wherein controlling the compressor start comprises:

controlling the compressors to start one by one, comparing the running time of the compressors, controlling the compressor with the shortest running time in the non-running compressors to start, and starting the first regulating valve corresponding to the compressor after the starting time of the compressor reaches t1;

7. The chiller control method of claim 2, wherein the chiller further comprises an economizer, the at least two compressors are connected to the economizer, a second regulating valve is further disposed on a pipeline connecting the economizer to the evaporator, the operating condition information further comprises a liquid level H of the economizer, and the method further comprises:

8. The method for controlling a water chiller according to claim 2 wherein the operating condition information further comprises a boost pressure value Pb and an intermediate pressure value Pm of the compressor, and further comprising, after the acquiring the operating condition information of the current operation of the water chiller:

judging whether the air supplementing pressure value Pb is smaller than the difference between the intermediate pressure value Pm and the tolerance delta P, if so, controlling the opening degree of a first regulating valve of the corresponding compressor to be increased, and if not, judging whether the air supplementing pressure value Pb is larger than the sum of the intermediate pressure value Pm and the tolerance delta P;

And if the pressure supplementing value Pb is larger than the sum of the intermediate pressure value Pm and the tolerance delta P, controlling the opening degree of the first regulating valve of the corresponding compressor to be reduced.

9. A chiller control apparatus, wherein the chiller includes at least two compressors arranged in parallel, the apparatus comprising:

10. A computer-readable storage medium, on which a computer program is stored, characterized in that the program, when executed by a processor, implements the water chiller control method as claimed in any one of claims 1 to 8.

11. The utility model provides a cooling water set, its characterized in that, cooling water set includes two at least compressors, the economic ware, the evaporimeter, the condenser of parallelly connected setting, wherein, the air supply mouth of two at least compressors respectively with the gas outlet of economic ware is connected, the liquid outlet of condenser with the inlet connection of economic ware, the import of evaporimeter with the liquid outlet connection of economic ware, correspond respectively on the pipeline that the air supply mouth of two at least compressors and the gas outlet of economic ware are connected and be provided with first governing valve, be provided with first throttling arrangement on the pipeline that the liquid outlet of condenser and the import of economic ware are connected, be provided with second throttling arrangement on the pipeline that the import of evaporimeter and the liquid outlet of economic ware are connected, cooling water set is used for realizing the step of cooling water set control method of any one of claims 1 to 8.

12. The chiller according to claim 11 wherein the outlet of the first throttling device is also connected to the inlet of the evaporator, a third regulating valve is provided on a line connecting the outlet of the first throttling device to the inlet of the evaporator, the third regulating valve being provided in parallel with the economizer;