A heat exchange unit operation control method

Abstract

The present invention provides a heat exchanger operation control method, which includes the following steps: obtaining the supply and return water temperatures of the secondary side of the heat exchanger and the return water temperature of each building or unit; using the data obtained in the above steps to calculate the thermal imbalance of each building or unit, and determine the minimum thermal imbalance value; judging whether to adjust the set frequency of the circulation pump according to the relationship between the minimum thermal imbalance value and the set threshold; the heat exchanger operates in accordance with the outdoor average temperature and the average supply and return water temperature comparison table or characteristic curve of the second network. The system includes a PLC controller, a heat exchanger, an electric regulating valve, a frequency converter, a circulation pump and a building or unit. This system uses the above operation control method, which can achieve the purpose of saving the power consumption of the circulation pump to the greatest extent without changing the heating effect and the heat consumption of the heat exchanger, thereby helping to reduce the heating operation cost.

Description

Technical Field

[0001] The invention relates to the technical field of energy-saving of heat exchange stations, and in particular to an operation control method of a heat exchange unit. Background Art

[0002] In the heating system, due to hydraulic imbalance, there is a common thermal imbalance phenomenon of uneven hot and cold. In order to improve the heating effect and overcome the thermal imbalance phenomenon, the domestic current often adopts the "large flow, small temperature difference" operation mode. Sometimes the operating flow of the second network far exceeds the need to overcome the thermal imbalance, resulting in a waste of power consumption of the circulation pump. Summary of the invention

[0003] The purpose of the present invention is to provide a method for controlling the operation of a heat exchanger unit. By utilizing the system and the heating operation control method of the system, it is possible to achieve the purpose of saving the power consumption of the circulation pump to the greatest extent without changing the heating effect and the heat consumption of the heat exchanger unit, thereby helping to reduce the heating operation cost.

[0004] The technical solution adopted by the present invention to solve the technical problem is: the present invention provides a heat exchange unit operation control method, comprising the following steps:

[0005] S1. Obtain the supply and return water temperatures of the secondary side of the heat exchanger unit and the return water temperature of each building or unit;

[0006] S2, using the supply and return water temperatures of the secondary side of the heat exchanger unit and the return water temperature data of each building or unit obtained in the above steps, calculate the thermal imbalance of each building or unit, and determine the minimum thermal imbalance value;

[0007] S3, determining whether to adjust the set frequency of the circulation pump according to the relationship between the minimum thermal imbalance value and the set threshold value;

[0008] S4. The heat exchanger unit operates according to the comparison table or characteristic curve of the outdoor average temperature and the average temperature of the secondary network supply and return water.

[0009] Preferably, the calculation formula for the thermal imbalance is: , where: x n is the thermal imbalance of the nth building or unit, t g is the water supply temperature of the second network of the heat exchanger unit, t h is the return water temperature of the second network of the heat exchanger unit, t n is the return water temperature of the nth building or the nth unit.

[0010] Furthermore, whether the circulating pump setting frequency is adjusted is based on the following steps:

[0011] (1) If the minimum thermal imbalance value x zdIf it is greater than the upper limit of the set threshold, it is determined whether the set frequency of the circulation pump is greater than the minimum operating frequency;

[0012] If yes, reduce the circulating pump setting frequency;

[0013] If not, keep the circulating pump set frequency unchanged;

[0014] (2) If the minimum thermal imbalance value x zd If it is within the set upper and lower threshold limits, the set frequency of the circulation pump remains unchanged;

[0015] (3) If the minimum thermal imbalance value x zd If it is less than the lower limit of the set threshold, it is judged whether the set frequency of the circulation pump is less than the rated frequency;

[0016] If yes, then increase the set frequency of the circulation pump;

[0017] If not, keep the circulating pump set frequency unchanged.

[0018] The present invention also provides a heat exchange unit operation control system, including a PLC controller, a heat exchange unit, an electric regulating valve, a frequency converter, a circulation pump and a building or unit, wherein the electric regulating valve is used to adjust the water supply on the primary side of the heat exchange unit; the secondary side of the heat exchange unit is connected to the building or unit through a second network water supply pipe and a second network return pipe, the circulation pump is connected in series to the second network return pipe, and the PLC controller realizes the operating frequency regulation of the circulation pump through the frequency converter. The operation control system also includes an outdoor temperature sensor, a first temperature transmitter, a second temperature transmitter and a third temperature transmitter. The outdoor temperature sensor is used to transmit outdoor temperature data to the PLC controller, and the PLC controller is provided with an outdoor average temperature The calculation module is used to calculate the average temperature value of the outdoor temperature within a period of time; the first temperature transmitter is used to transmit the water supply temperature of the second network to the PLC controller, the second temperature transmitter is used to transmit the return water temperature of the second network to the PLC controller, and the third temperature transmitter is used to transmit the return water temperature of each building or unit to the PLC controller; a thermal imbalance calculation and determination module is provided in the PLC controller, and the thermal imbalance calculation and determination module is used to calculate the thermal imbalance of each building or unit according to the supply and return water temperatures on the secondary side of the heat exchanger unit and the return water temperature data of each building or unit, and determine the minimum thermal imbalance value.

[0019] Preferably, in the PLC controller, a thermal imbalance calculation and determination module is provided, which is provided according to the formula The thermal imbalance calculation module performs the calculation, where: x n is the thermal imbalance of the nth building or unit, t gis the water supply temperature of the second network of the heat exchanger unit, t h is the return water temperature of the second network of the heat exchanger unit, t n is the return water temperature of the nth building or the nth unit.

[0020] Preferably, a comparison table or characteristic curve of the outdoor average temperature and the average temperature of the water supply and return water of the second network is stored in the PLC controller.

[0021] The beneficial effects of the present invention are as follows: the operation control method provided by the present invention can adjust the working frequency of the circulation pump according to the comparison relationship between the minimum thermal imbalance value and the set upper and lower threshold values, so that the circulation pump is in the best operating state to overcome the thermal imbalance, thereby avoiding the operation flow of the second network exceeding the need to overcome the thermal imbalance, causing the waste of power consumption of the circulation pump, and then helping to reduce the heating operation cost; while adjusting the operating frequency of the circulation pump, the system can adjust the heating heat of the first network according to the weather conditions, so that the heating heat is adjusted according to the weather changes, thereby avoiding the occurrence of heat supply exceeding the heat demand, achieving heat saving, and then also achieving heating energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the overall operation flow of the heat exchange unit operation control method;

[0024] Figure 2 It is a schematic diagram of the operation flow of a specific embodiment of the set frequency adjustment operation of the circulation pump in the heat exchange unit operation control method;

[0025] Figure 3 A schematic diagram of the composition framework of a heating system provided by the present invention;

[0026] In the figure: 1 PLC controller, 2 heat exchange unit, 3 circulation pump, 4 frequency converter, 5 outdoor temperature sensor, 6 building or unit, 101 first network water supply pipe, 102 first network return pipe, 103 second network water supply pipe, 104 second network return pipe, 105 building or unit water supply pipe, 106 building or unit return pipe, 201 first temperature transmitter, 202 second temperature transmitter, 203 third temperature transmitter, 301 electric regulating valve. DETAILED DESCRIPTION

[0027] The following will be combined with specific embodiments and attached Figure 1-3 , the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the preferred embodiments of the present invention, rather than all the embodiments. Those skilled in the art can make similar modifications without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0028] The present invention provides a heat exchange unit operation control method, which is characterized by comprising the following steps:

[0029] S1. Obtain the supply and return water temperatures of the secondary side of the heat exchanger unit and the return water temperature of each building or unit;

[0030] S2, using the supply and return water temperatures of the secondary side of the heat exchanger unit and the return water temperature data of each building or unit obtained in the above steps, calculate the thermal imbalance of each building or unit, and determine the minimum thermal imbalance value;

[0031] S3, determining whether to adjust the set frequency of the circulation pump according to the relationship between the minimum thermal imbalance value and the set threshold value;

[0032] S4. The heat exchanger unit operates according to the comparison table or characteristic curve of the outdoor average temperature and the average temperature of the secondary network supply and return water (in this step, the average temperature of the secondary network supply and return water refers to the average value of the secondary network supply water temperature and the secondary network return water temperature).

[0033] In the above step S1, the supply and return water temperatures on the secondary side of the heat exchanger unit 2 and the return water temperature of each building or unit can be monitored by the temperature transmitter and transmitted to the relevant heating operation controller.

[0034] In the above step S2, the calculation formula of the thermal imbalance is: , where: x n is the thermal imbalance of the nth building or unit, t g is the water supply temperature of the second network of the heat exchanger unit, t h is the return water temperature of the second network of the heat exchanger unit, t n is the return water temperature of the nth building or the nth unit. n After that, by comparing each x n After that, the minimum thermal imbalance value x is output zd .

[0035] In step S3, according to the minimum thermal imbalance value x zd The relationship between the minimum thermal imbalance value x and the set threshold value determines whether to adjust the set frequency of the circulation pump. The specific implementation method is as follows: (1) If the minimum thermal imbalance value x zdIf it is greater than the upper limit of the set threshold, it is determined whether the set frequency of the circulation pump is greater than the minimum operating frequency;

[0036] If yes, reduce the circulating pump setting frequency;

[0037] If not, keep the circulating pump set frequency unchanged;

[0038] (2) If the minimum thermal imbalance value x zd If it is within the set upper and lower threshold limits, the set frequency of the circulation pump remains unchanged;

[0039] (3) If the minimum thermal imbalance value x zd If it is less than the lower limit of the set threshold, it is judged whether the set frequency of the circulation pump is less than the rated frequency;

[0040] If yes, then increase the set frequency of the circulation pump;

[0041] If not, keep the circulating pump set frequency unchanged;

[0042] At the above minimum thermal imbalance value x zd In the comparison process with the upper and lower thresholds, the upper threshold can be set to 0.99 and the lower threshold can be set to 0.95.

[0043] The present invention also provides a heat exchanger unit operation system that can perform the above-mentioned operation control method. Specifically, the operation control system includes: a PLC controller 1, a heat exchanger unit 2, an electric regulating valve 301, a frequency converter 4, a circulating pump 3 and a building or unit 6. The electric regulating valve 301 is used to adjust the water supply on the primary side of the heat exchanger unit 2. The specific implementation method of the electric regulating valve 301 and the primary side of the heat exchanger unit 2 is as follows: a network water supply pipe 101 and a network return pipe 102 are arranged on the primary side of the heat exchanger unit 2, and the electric regulating valve 301 is arranged on the network water supply pipe 101, and the valve opening of the electric regulating valve 301 is changed by the PLC controller 1, thereby realizing the adjustment of the water supply on the primary side of the heat exchanger unit 2. The secondary side of the heat exchanger unit 2 is connected with the building or unit through the second network water supply pipe and the second network return pipe. The specific implementation method of the heat exchanger unit 2 and the building or unit 6 is as follows: the second network water supply pipe 103 and the second network return pipe 104 are correspondingly connected with the secondary side of the heat exchanger unit 2, the water supply pipe 105 of each building or unit 6 is connected with the second network water supply pipe 103 in parallel, and the return pipe 106 of each building or unit is connected with the second network return pipe 104 in parallel. The circulation pump 3 is connected in series to the second network return pipe 104, and the PLC controller 1 realizes the working frequency regulation of the circulation pump 3 through the frequency converter 4; the operation system of the heat exchange unit also includes an outdoor temperature sensor 5, a first temperature transmitter 201, a second temperature transmitter 202 and a third temperature transmitter 203. Specifically, the outdoor temperature sensor 5 is arranged at a monitoring point set by the outdoor environment, the first temperature transmitter 201 is arranged on the second network water supply pipe 103, the second temperature transmitter 202 is arranged on the second network return pipe 104, and the third temperature transmitter is arranged on the return pipe 106 of each building or unit; the outdoor temperature sensor 5 is used to transmit outdoor temperature data to the PLC controller 1, and the PLC controller 1 is provided with an outdoor average temperature calculation module, and the outdoor average temperature calculation module is used to calculate Calculate the average temperature value of the outdoor area within a period of time; the first temperature transmitter 201 is used to transmit the water supply temperature of the second network to the PLC controller 1, the second temperature transmitter 202 is used to transmit the return water temperature of the second network to the PLC controller 1, and the third temperature transmitter 203 is used to transmit the return water temperature of each building or unit 6 to the PLC controller 1; a thermal imbalance calculation and determination module is provided in the PLC controller 1, and the thermal imbalance calculation and determination module is used to calculate the thermal imbalance of each building or unit based on the supply and return water temperatures on the secondary side of the heat exchanger unit and the return water temperature of each building or unit, and determine the minimum thermal imbalance value. Specifically, in the thermal imbalance calculation and determination module provided in the PLC controller, a The thermal imbalance calculation module is based on the formula, where: x n is the thermal imbalance of the nth building or unit, tg is the water supply temperature of the second network of the heat exchanger unit, t h is the return water temperature of the second network of the heat exchanger unit, t n It is the return water temperature of the nth building or the nth unit; further, for the convenience of the PLC controller 1, the water supply of the first network can be adjusted according to the relationship between the average outdoor temperature and the average supply and return water temperature of the second network. Here, a comparison table or characteristic curve of the average outdoor temperature and the average supply and return water temperature of the second network is stored in the PLC controller.

[0044] A specific embodiment of the above operation control method using the heat exchange unit is:

[0045] In the first step, the staff starts the operation module of the above operation control method set in the PLC controller 1 according to the needs;

[0046] In the second step, PLC controller 1 uses the formula Calculate the thermal imbalance corresponding to each building or unit, where: x n is the thermal imbalance degree of the nth building or the nth unit, tg is the water supply temperature of the second network of the heat exchanger unit, which is monitored by the first temperature transmitter 201, th is the return water temperature of the second network of the heat exchanger unit, which is monitored by the second temperature transmitter 202, and tn is the return water temperature of the nth building or unit, which is monitored by the third temperature transmitter 203 corresponding to the nth building or unit;

[0047] After the PLC controller 1 calculates the thermal imbalance of each building or unit, it compares the thermal imbalances and then determines the minimum thermal imbalance x. zd， , then, according to the minimum thermal imbalance value x zd The relationship between the set threshold and the frequency of the circulating pump is used to determine whether to adjust the set frequency of the circulating pump. The specific implementation method is as follows:

[0048] (1) If the minimum thermal imbalance value x zd If it is greater than the upper limit of the set threshold, it is determined whether the set frequency of the circulation pump is greater than the minimum operating frequency;

[0049] If yes, reduce the circulating pump setting frequency;

[0050] If not, keep the circulating pump set frequency unchanged;

[0051] (2) If the minimum thermal imbalance value x zd If it is within the set upper and lower threshold limits, the set frequency of the circulation pump remains unchanged;

[0052] (3) If the minimum thermal imbalance value x zd If it is less than the lower limit of the set threshold, it is judged whether the set frequency of the circulation pump is less than the rated frequency;

[0053] If yes, then increase the set frequency of the circulation pump;

[0054] If not, keep the circulating pump set frequency unchanged;

[0055] At the above minimum thermal imbalance value x zd In the comparison process with the upper and lower thresholds, the upper threshold can be set to 0.99 and the lower threshold can be set to 0.95.

[0056] Step 3: After the frequency setting of the circulation pump 3 is completed, the PLC controller 1 adjusts the water supply on the primary side of the heat exchanger unit 1. Specifically, the PLC controller 1 calculates the average outdoor temperature in the local heating area in the recent time period based on the data transmitted by the outdoor temperature sensor, and then compares the average outdoor temperature in the recent time period with the outdoor average temperature and the secondary network supply and return water average temperature comparison table or characteristic curve stored in the PLC controller to obtain the secondary network supply and return water average temperature control corresponding value corresponding to the outdoor temperature average in the recent time period. After the secondary network supply and return water average temperature control corresponding value is obtained, the PLC controller 1 controls the electric regulating valve 301 according to the set control program based on the secondary network supply and return water average temperature control corresponding value, so that the secondary network supply and return water average temperature value in actual operation is close to the obtained secondary network supply and return water average temperature control corresponding value.

[0057] The control process of the PLC controller 1 using the outdoor average temperature of the recent time period to control the average temperature of the supply and return water of the second network is illustrated as follows: the recent time period is set to yesterday's 24 hours, and the PLC controller 1 calculates the average temperature range within yesterday's 24 hours as -2°C. By comparing the average temperature comparison table or characteristic curve of the supply and return water of the second network, it can be seen that the average temperature of the supply and return water of the second network corresponding to -2°C is 75°C. Then, the PLC controller 1 adjusts the opening degree of the electric regulating valve 301 to increase or decrease the heating amount of the first network, so that the average temperature of the supply and return water of the second network approaches 75°C, thereby realizing the control process of adjusting the heating according to weather changes.

[0058] Except for the technical features described in the specification, all other technical features are known technologies to those skilled in the art.

[0059] The above description in combination with the accompanying drawings has detailed the preferred implementation modes and embodiments of the present invention, but the present invention is not limited to the above implementation modes and embodiments. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the concept of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A heat exchange unit operation control method, Its characteristics are: The invention comprises a heat exchange unit operation control system, which comprises a PLC controller, a heat exchange unit, an electric regulating valve, a frequency converter, a circulation pump and a building or a unit. The electric regulating valve is used to adjust the water supply on the primary side of the heat exchange unit. The secondary side of the heat exchange unit is connected with the building or the unit through a second network water supply pipe and a second network return pipe. The circulation pump is connected in series to the second network return pipe. The PLC controller realizes the operating frequency regulation of the circulation pump through the frequency converter. The operation control system further comprises an outdoor temperature sensor, a first temperature transmitter, a second temperature transmitter and a third temperature transmitter. The outdoor temperature sensor is used to transmit outdoor temperature data to the PLC controller. The PLC controller is provided with an outdoor average temperature calculation module. The temperature calculation module is used to calculate the average temperature value of the outdoor area within a period of time; the first temperature transmitter is used to transmit the water supply temperature of the second network to the PLC controller, the second temperature transmitter is used to transmit the return water temperature of the second network to the PLC controller, and the third temperature transmitter is used to transmit the return water temperature of each building or unit to the PLC controller; a thermal imbalance calculation and determination module is provided in the PLC controller, and the thermal imbalance calculation and determination module is used to calculate the thermal imbalance of each building or unit based on the supply and return water temperatures on the secondary side of the heat exchanger unit and the return water temperature of each building or unit, and determine the minimum thermal imbalance value; a thermal imbalance calculation and determination module is provided in the PLC controller, and a The thermal imbalance calculation module is based on the formula, where: x n is the thermal imbalance of the nth building or unit, t g is the water supply temperature of the second network of the heat exchanger unit, t h is the return water temperature of the second network of the heat exchanger unit, t n is the return water temperature of the nth building or the nth unit; a comparison table or characteristic curve of the outdoor average temperature and the average temperature of the second network supply and return water is stored in the PLC controller; The heat exchange unit operation control method also includes the following steps: S1. Obtain the supply and return water temperatures of the secondary side of the heat exchanger unit and the return water temperature of each building or unit; S2. Using the supply and return water temperatures of the secondary side of the heat exchanger unit and the return water temperature data of each building or unit obtained in the above steps, calculate the thermal imbalance of each building or unit, and determine the minimum thermal imbalance value; the calculation formula of the thermal imbalance is: , where: x n is the thermal imbalance of the nth building or unit, t g is the water supply temperature of the second network of the heat exchanger unit, t h is the return water temperature of the second network of the heat exchanger unit, t n is the return water temperature of the nth building or the nth unit; S3. Determine whether to adjust the set frequency of the circulation pump according to the relationship between the minimum thermal imbalance value and the set threshold value; whether the set frequency of the circulation pump is adjusted is based on the following steps: 3.

1. If the minimum thermal imbalance value x zd If it is greater than the upper limit of the set threshold, it is determined whether the set frequency of the circulation pump is greater than the minimum operating frequency; If yes, reduce the circulating pump setting frequency; If not, keep the circulating pump set frequency unchanged; 3.

2. If the minimum thermal imbalance value x zd If it is within the set upper and lower threshold limits, the set frequency of the circulation pump remains unchanged; 3.

3. If the minimum thermal imbalance value x zd If it is less than the lower limit of the set threshold, it is judged whether the set frequency of the circulation pump is less than the rated frequency; If yes, then increase the set frequency of the circulation pump; If not, keep the circulating pump set frequency unchanged; S4. The heat exchanger unit operates according to the comparison table or characteristic curve of the outdoor average temperature and the average temperature of the secondary network supply and return water.

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