CN101334191A - Distributed intermittent heating control system - Google Patents

Abstract

The distributed intermittent heating control system belongs to the technical field of building heating system control. It is aimed at the ubiquitous energy waste problems such as "excessive capital and utilization pressure head, small temperature difference and large flow" in the heating operation of northern cities, and the current situation of lack of implementation behavior and energy-saving force points for mixed networks with different heat demands. Through the distributed transmission and distribution control design, the combination of intermittent heat collection from heat sources and on-demand continuous cycle heat supply to heat users is realized, thereby increasing the temperature difference between supply and return water, reducing the flow of system pipe networks, and reducing or eliminating the pressure of excess capital. Head, to meet the different thermal needs of different time periods of thermal user groups, and provide a foundation for household metering. By providing specific application points, the huge energy-saving space under the current operating conditions is transformed into a significant energy-saving reality. It has obvious energy-saving effect, good heating safety, and strong adaptability, and is suitable for new systems and old system renovations.

Description

Distributed intermittent heating control system

technical field

The invention belongs to the technical field of building heating system control. It is aimed at the ubiquitous energy waste problems such as "excessive capital and utilization pressure head, small temperature difference and large flow" in the heating operation of northern cities, and the current situation of lack of implementation behavior and energy-saving force points for mixed networks with different heat demands. Through the distributed transmission and distribution control design, the combination of intermittent heat collection from heat sources and on-demand continuous cycle heat supply to heat users is realized, thereby increasing the temperature difference between supply and return water, reducing the flow of system pipe networks, and reducing or eliminating the pressure of excess capital. Head, to meet the different thermal needs of different time periods of thermal user groups, and provide a foundation for household metering. By providing specific application points, the huge energy-saving space under the current operating conditions is transformed into a significant energy-saving reality.

Background technique

The existing heat supply technology is based on the centralized circulation pump of the heat exchange station, which acts as the heat source pump, heat network pump and heat user pump to complete the entire transmission and distribution process of the heat medium. It is bound to be difficult to take into account and satisfy the entire Different heat demands of many heat users in different time and space in the heat network. Large flow and small temperature difference (about 10 degrees) are formed, and the return water temperature is high; relying on the high lift provided by the circulating pump at the outlet of the heat source to meet the resource pressure head at the most unfavorable heat user, often resulting in hydraulic and thermal imbalance , forming near heat and far cold; the system provides full-time heating, which causes huge waste because it cannot be adjusted according to needs in time-sharing and partitions.

Contents of the invention

The purpose of the present invention is to provide a distributed intermittent heating control system that solves the problem of "surplus pressure head, small temperature difference and large flow", so as to achieve the purpose of eliminating and improving a series of related problems.

The technical solution of the present invention is that the transformation of the controlled system is reflected in the hardware, including the installation of electric switching valves, the addition of bypass pipelines, and the configuration of variable frequency pumps; the software and methods are built into the intelligent controller of the measurement and control system. The distributed frequency conversion heat user pumps are used to undertake the tasks of heat collection and internal circulation from the main pipe, adapt to high-lift heat production and low-lift internal circulation with frequency conversion, and respond to changes in the heat load of heat users in the subsystem; realize the elimination or reduction of the pipe network Excess capital uses the pressure head, and can reduce the amount of hot water transmission and distribution as the load decreases, thereby reducing power and heat consumption. The water mixing ratio during heating is realized through the initial adjustment of the electric on-off valve of the subsystem and the manual valve of the bypass pipe, so as to adapt to the heating requirements of different heat users (radiators, geothermal, etc.). The electric switching valve of the subsystem is used to adjust and increase the temperature difference between the supply and return water, thereby reducing the amount of hot water transmission and distribution of the main pipe, realizing power saving or increasing the heat transfer capacity of the main pipe. The internal circulation of the heat user pump can improve the terminal heating effect and easily adapt to the needs of household metering. This scheme can realize "when to use, when to use, and how much to use", which has obvious energy-saving effect, good heating safety, strong adaptability, and can be applied to new systems and old system renovations.

The hardware configuration of this scheme mainly includes installing an electric on-off valve on the branch line of the water supply pipe, adding a bypass pipe with the same diameter as the branch line and equipped with a manual regulating valve between the water supply and return lines of the branch line, and installing a manual regulating valve on the return line of the branch line. A variable frequency pump is installed on the water pipeline, as well as an intelligent controller connected with relevant temperature and pressure sensors. See attached drawing 1.

As shown in Figure 1, its composition includes: a heat source circulation pump 1, a main network water supply pipe 2 and a return water pipe 3 connected to the heat source, a bypass pipe 4 connecting the branch water supply and return pipes of the building, and a water supply pipe on the branch water supply pipe. Electric switch valve 5, manual valve on bypass pipe 6, heat user building 7, frequency conversion heat user pump 8, water supply temperature and pressure sensors 9, 10, return water temperature and pressure sensors 11, 12, temperature after mixing water, Pressure sensors 13, 14, ambient temperature sensor 15 and intelligent controller 16.

The main external performance of the present invention is:

(1) The intelligent intermittent technology includes not only the intelligent interval after distinguishing between the "heating period" and the "antifreeze period", but also the intelligent interval in the "heating period" and "antifreeze period". The traditional heating system operates in the state of "small temperature difference, large flow", and there is a lot of waste of electric energy; the purpose of intermittent heating is to increase the temperature difference between supply and return water through the internal circulation of heat users and frequency conversion water mixing technology, so that the system can operate In the energy-saving state of "large temperature difference, small flow".

(2) Distributed heating adjustment, real-time changes in heat load will inevitably break the original constant flow transmission and distribution hydraulic balance. Transform the original stable heat supply mode into a dynamic intermittent heating mode from the pipe network using frequency conversion technology according to heat demand. Eliminate or reduce the pressure head of excess resources, reduce the energy consumption of transmission and distribution; and provide power for the internal circulation of the subsystem in real time, and provide convenience for household adjustment behavior and energy saving.

The system works as follows:

During the rough debugging of the system, according to the actual situation of the heat users (ground heat, heat sink, etc.), the water mixing ratio required is adjusted and the manual valve 6 does not need to be changed. During the normal heating period, the intelligent controller 16 compares the return water temperature Th provided by the return water temperature collector 11 with the preset value in real time. When Th is higher than the set value, it means that the heat medium in the branch is still If it can continue to provide heat for the heat user, it remains closed, and the frequency conversion pump 7 maintains a constant pressure of self-circulation in the building, so that the heat user building 7 operates in the state of internal circulation and heat dissipation. When Th is lower than the set value, the electric valve 5 is opened, and the frequency conversion pump 8 needs to overcome the pressure drop from the heat source to the heat user main pipe and the pressure required by the building 7 to operate. The subsystem participates in the entire pipeline network cycle to complete heat extraction from the heat source. The intelligent controller 16 calculates the temperature difference ΔT of the supply and return water according to the temperature Tg and Th of the supply and return water. If ΔT>the preset value, it means that the heat medium in the building 7 has not been replaced. Valve 5, the system switches to the internal circulation cooling operation state. Cycle through.

The beneficial effects and benefits achieved by the present invention are that, with the popularization and implementation of household metering, the system changes from the original starting from the supply side and the passive acceptance of the demand side to starting from the demand side and responding in real time from the supply side. This brings about major changes in the entire heating control management. The operation of the system can save about 20-40% of heat and 50-70% of electricity through behavioral energy-saving, and correspondingly have significant environmental benefits.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a configuration diagram of the distributed intermittent heating control system of the present invention.

Fig. 2 is a logic diagram of the intelligent controller software of the present invention.

Detailed ways

This system includes: the main network water supply pipe 2 and the return water pipe 3 connected to the heat source, the bypass pipe 4 connected to the branch water supply and return pipes of the building, and the electric switch valve 5 on the branch water supply pipe, that is, the main pipeline of the building. Manual valve on the bypass pipe 6, heat user building 7, variable frequency heat user pump 8, supply water temperature and pressure sensors 9, 10, return water temperature and pressure sensors 11, 12, mixed water temperature and pressure sensors 13, 14 , ambient temperature sensor 15 and intelligent controller 16.

The system works as follows:

During the rough debugging of the system, according to the actual situation of the heat users (ground heat, heat sink, etc.), the water mixing ratio required is adjusted and the manual valve 6 does not need to be changed. During normal heat supply, the intelligent controller 16 compares the return water temperature Th provided by the return water temperature collector 11 with the preset value in real time. When Th is higher than the set value, it means that the heat medium in the branch can still Continue to provide heat for the heat user, then keep off, the variable frequency pump 8 maintains the constant pressure of the self-circulation in the building, so that the heat user building 7 operates in the internal circulation heat dissipation state. When Th is lower than the set value, the electric valve 5 is opened, and the frequency conversion pump 8 needs to overcome the pressure drop from the heat source to the heat user main pipe and the pressure required by the building 7 to operate. The subsystem participates in the entire pipeline network cycle to complete heat extraction from the heat source. The intelligent controller 16 calculates the temperature difference ΔT of the supply and return water according to the temperature Tg and Th of the supply and return water. If ΔT>the preset value, it means that the heat medium in the building 7 has not been replaced. Valve 5, the system switches to the internal circulation cooling operation state. Cycle through.

Claims (1)

1. The distributed intermittent heating control system is characterized in that it consists of hardware and software. a. The hardware part includes: the main network water supply pipe (2) and the return water pipe (3) connected to the heat source, the bypass pipe (4) connecting the branch water supply and return pipes of the building, on the branch water supply pipe, that is, the building The electric switch valve (5) of the main pipeline, the manual valve (6) on the bypass pipe, the heat user building (7), the frequency conversion heat user pump (8), the water supply temperature and pressure sensors (9), (10), the return Water temperature and pressure sensors (11), (12), temperature after mixing water, pressure sensors (13), (14), ambient temperature sensor (15) and intelligent controller (16); b. The system operates as follows: When the system is roughly debugged, the manual valve (6) does not need to be modified after the manual valve (6) is adjusted according to the water mixing ratio required by the actual situation of the heat user; The return water temperature Th provided in real time is compared with the preset value. When Th is higher than the set value, it means that the heat medium in the branch can continue to provide heat for the heat user, and then it is kept closed, and the variable frequency pump (8) maintains The self-circulation constant pressure in the building makes the heat user building (7) run in the internal circulation heat dissipation state; when Th is lower than the set value, the electric valve (5) is opened, and the frequency conversion pump (8) needs to overcome the heat source to dry the heat user The pressure drop of the pipe and the pressure required by the building (7), the subsystem participates in the entire pipe network cycle, and completes the heat collection from the heat source; the intelligent controller (16) calculates the temperature difference ΔT of the supply and return water according to the supply and return water temperature Tg, Th, if ΔT>preset value, indicating that the replacement of the heat medium in the building (7) has not been completed, continue to maintain the heating state until ΔT<preset value, close the electric valve (5), and the system switches to the internal circulation heat dissipation operation state; the cycle continues.

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