Control valve repair, heating system, the application is very broad usage, therefore, do a good job regulating valve for heating system repairs and heating system control valve maintenance, has far-reaching significance; the Jiangyin City Oulei Si valve repair factory, or more important to focus on regulating valve maintenance.
Let's come to know what control valves in the heating system: an effective energy-saving heating systems are equipped with a corresponding adjustment control equipment, such as self-flow, pressure control valve. With the reform of the system of heat metering charges, indoor heating system assembly thermostatic valve after proper heating network with control equipment is very important. This paper discusses the changes in the characteristics of the assembly the thermostatic valve before and after system, pointed out that a properly equipped with thermostatic valve control equipment, guidance on the design and renovation.
With the reform of the heating heat metering and charging system, must be installed on the radiator thermostatic valve. As the user adjustment of thermostatic valve in the heating operation, the district heating network traffic is changing. Become our heating network variable flow operation, flow regulation initiative lies in the hands of users, and the temperature will not be able to predict and control the flow changes. In the case of the variable flow operation of this thermostatic valve, regulation and control devices must be properly installed to play a role. Otherwise, cause the system to not only reach the conditioning requirements, and sometimes counterproductive.
What is a control and regulating device: control what valve regulating device?
Self-pressure control valve
Similar to the characteristics of self-operated pressure control valve operated flow control valve, and it does not need an external power, rely solely on the characteristics of fluid flow on and / or downstream of the resistance to change within a certain range, it can through the pipeline The changes in the pressure within the self-adjusting the degree of opening, so that the pressure drop changes in the fluid through the valve when the heart to compensate for changes in the pipeline resistance, so that a user's inlet pressure remains substantially unchanged.
Balancing valve
Adjust the basic principles of perspective, balance valve is actually a manual control valve opening direction. Upstream of the balancing valve, the downstream end of the tube a pressure taps, used for measuring the fluid pressure drop through the valve. When used, the measured degree of opening of the valve pressure drop and read out, can be regarded as the flow through the valve. The acts regulating valve and the combination of the equivalent orifice flow meter, flow distribution of the various branches meet the requirements. When the the total circulation pump variable speed operation, the proportion of each branch flow distribution remain
unchanged.
Operated flow control valve
The characteristics of the valve without external power, relying on the flow characteristics of the fluid in the upper and / or downstream of the resistance is changed within a certain range, it can adjust the degree of opening by the pressure changes within the pipe itself, so that the flow rate remains substantially unchanged.
The only discussion of the three conditioning equipment, and conditioning is not installed in the heating risers, but mounted on the heat at the entrance of the floor.
Not equipped with thermostatic valve flow run system of regulating control
The constant flow run talking about here is the entire heating season heat network traffic remain unchanged.
Directly connected network
In general, the directly connected network as the boundary of the thermal station the main part of the network and branch network, mainly from the heat source to the thermal station network, user support network to the heat from the thermal station.
Main network adjustment
The main network control strategy to regulate the water supply valve opening degree of the thermal station, all thermal stations return water temperature consistent. The main network should be equipped with computer control, so you can ensure the quality of the heating, while reducing operating costs. But when the investment is limited or heating network is small, the size of the heating network is relatively stable, but also without microcomputer control, while the use of relatively simple adjustment method, described in the following sub-networks.
Branch network regulation
Heating network computer control high investment, it is generally only control the main network. Can have a variety of adjustment method for the branched network.
Manual adjustment
Manually adjust each branch valve, so that each user's basic flow of the design flow. But the branch road is generally no flow measurement devices, and therefore can not directly observe the flow rate to determine whether the adjustment to meet the requirements. There are two ways: by observing the return water temperature of each branch, and constantly adjust the valve of the branch, so that each branch of the return water temperature close to the same; or portable ultrasonic flowmeter observations for each branch of the flow to adjust, the actual flow of each branch can be transferred to the value of the design requirements. Return water temperature to adjust to need a longer adjustment period, because of the thermal inertia of the building; portable ultrasonic flowmeter adjustment is simple, but the need to purchase the appropriate equipment.
Operated flow control valve
Operated flow control valve is installed in each branch circuit or thermal entrance, set the knob to adjust the control valve to traffic instructions to achieve the requirements of the design flow. In this way, in the run-time flow of each branch can basically meet the design requirements.
Balancing valve
Support on the road or thermal entrance installed balancing valve, according to the balance valve adjustment method, according to the branch of the design flow, adjusting the opening balance valve so that it flows to meet the design
requirements. Thus, in the run-time of each branch flow can meet the design requirements. Self-pressure control valve
Self-operated differential pressure control valve installed in various branches on the road or thermal entrance, set the knob to adjust the pressure control valve, so that the differential pressure indicated value of design owned indenter. Generally, the the designer given design flow rate and the actual desired flow rate should be relatively close, so two adjustment method is more accurate; owned indenter is not only related to the design flow rate, and pipeline resistance coefficient, but actual slip resistance coefficient may be related to the design value difference between the larger, so that even if the actual pressure is adjusted to design owned indenter may cause the actual flow rate less than the design flow due to the difference of the drag coefficient, resulting in hot and cold uneven .
Adjustment method comparison
For the full heating season using a fixed flow rate of the heating network, on several regulation can be used. Manual adjustment and adjustment of the throttle adjustment method belonging to the same type, are actually beginning to adjust to meet the requirements to maintain the allocation ratio of each branch flow, i.e. after the adjustment is completed, but when the heating network to add a new user or existing user's workstation conditions change, the flow distribution ratio, and therefore they need to be re-adjusted. Meanwhile, in the adjustment process, due to the coupling relationship between the respective users, such as user traffic A adjusted to a value of the design requirements, but when the regulation of the B-subscriber, due to the coupling effect, the flow of the user's A occurred changes, such as the coupling is severe, A Users also need to re-adjust. Therefore, using the method of this adjustment, serious coupled to each user must be well decoupled processing.
Operated flow control valve and self-operated pressure control valve with the two regulators, and its role is not to ensure that the proportion of flow distribution, but rather to ensure that the valves are responsible for the support on the road traffic (pressure) remains unchanged. Heating networks add new users, the original branch flow affected it can automatically adjust to adapt to these changes, so as to maintain the slip flow constant the original branch operated flow (differential pressure ) control valve does not need to be re-adjusted.
Of course, all adjustments to the system to add some resistance, but also requires that the system have enough adjustment margin.
Between networked mixed networking
From a control point of view, the difference is that the mix of networking and inter-networking thermal station the water temperature of the secondary network control method. The thermal station network for inter-networking, regulating valve to control the temperature of the secondary network backwater, regulating the flow of the secondary circulation pumps to control the temperature of the water supply of the secondary network; For mixed networking also adjust the heat station once a network of valves to control the secondary net return water temperature, secondary network of water supply temperature by adjusting the mixing pump flow control.
Inter-networking or mixed network a network, each of the thermal station is equivalent to a heat user, the primary network is equivalent to a directly connected network, and the said straight networked adjusting method is also applicable; for the secondary network, thermodynamic The station is equivalent to the heat source, the secondary network is equivalent to a directly connected network, the directly connected network adjustment method fully applicable. Therefore, direct network adjustment method can be extended to inter-networking and mixed networking.
Not installed the operating system adjust the thermostatic valve phased variable flow control
Phased variable flow is divided into several stages throughout the heating season, the flow remains constant within each stage, from a stage of transition to another phase, the flow change. For example, the entire heating season is divided into the heating early - cold - heating the final three stages, the heating network traffic flow - flow - small flow of three flow value. From throughout the heating season, the flow is no longer completely fixed. Therefore, this mode of operation, the adjusting method described in the previous section are not necessarily all appropriate.
Article explains:
Paper series site or of self-publish, the site post aims to deliver more information to the visitor.
2, involving work content, copyright and other issues, please contact site within 30 days, we will be the first time to make appropriate treatment! About copyright issues, please contact: 13515194999
3, Zhuanzhai this article please indicate from: Jiangyin City Oulei Si valve valve repair factory www.olschina.com
4 other links: valve repair, valve repair, valve repair equipment, valve grinding machine, the inlet valve repair, power station valve repair, regulating valve repair |
