Heat Metering Technical Regulations
JCJ 173-2009 Please refer to the new version of the "Heat Metering Technical Regulations" (2010 edition) available in bookstores
Article Description
Objective
1 General Provisions
2 Terminology
3 Basic Regulations
4.1 Measurement Methods
4.2 Regulation and Control
4. 4 Heat source and heat station heat metering
4.1 Measurement methods
4.2 Regulation and control
5 Building heat metering
5.1 Measurement methods
5.2 Regulation and control
6 Household heat metering
6.1 General provisions
6.2 Radiator heat distribution metering method
6.3 Household Heat Meter Method
7 Indoor Heating System
7.1 System Configuration
7.2 System Regulation
1 General Principles
1.0.1 The purpose of heat metering is to promote the reform of the urban heating system, to ensure the quality of heat supply, and reform of the charging system, and to realize the energy saving and reduction of consumption. Room temperature regulation and other energy-saving control technology is an important prerequisite for heat metering, but also reflects the heat metering energy-saving effect of the basic means. Article 38 of the Energy Conservation Law of the People's Republic of China stipulates that the State shall take measures to implement the system of heat metering and charging according to the amount of heat consumed in a step-by-step manner for buildings with centralized heat supply. New buildings or energy-saving renovation of existing buildings shall install heat metering devices, indoor temperature control devices and heating system control devices in accordance with the regulations. Therefore, this regulation to realize the household heat metering as a starting point, in the provisions of the heat metering method, measuring instruments and construction requirements, but also provides for the corresponding energy-saving control technology.
5 heat metering technical regulations
1.0.2 These regulations for new construction, renovation and expansion of civil buildings, as well as existing civil buildings are applicable to the transformation.
1.0.3 The regulations in the tightly focused on heat measurement and energy saving goals forward, leaving a large technical space and leeway, there is no mandatory heat measurement methods, methods and appliances, for the localities in accordance with their own specific circumstances of their own choice. In particular, a number of methods of sub-household heat metering have their own shortcomings, there is no perfect method, need to be analyzed on a case-by-case basis, choose the more applicable measurement methods.
2 terminology
2.0.4 heat metering devices, including heat meters for heat settlement, as well as for a number of different user heat apportionment methods used by the instrumentation.
2.0.5 heat measurement devices, including heat meters in line with the "heat meter" CJ 128 product standards, but also other users of their own management of the use of heat measurement instrumentation is not used for settlement.
2.0.6 sub-household heat metering from the point of view of measurement and settlement, divided into two methods, one is the use of building heat meters for building measurement and then apportioned according to the household; the other is the use of household heat meters according to the household measurement and direct settlement. Among them, there are several methods of apportionment by household. This terminology lists the current application of the four methods of apportionment, in no particular order, and their working principles are as follows:
Radiator heat distribution meter method is installed in each group of radiators on the radiator heat distribution meter (referred to as the heat distribution meter) for the user's heat apportionment method.
The flow-temperature method is a way of user heat apportionment through continuous measurement of the temperature difference between the inlet and outlet of the radiator or **** with a riser of a separate household independent system, combined with the measured flow proportionality relationship between each riser or separate household independent system and the heat population.
The on-off time area method is to control the electric on-off valve installed on the inlet branch pipe of the heating system of each household through the temperature control device, according to the on-off time of the valve and the floor area of each household for the user heat apportionment method.
The household heat meter method is through the household heat meter installed in each household for user heat apportionment, using the household meter as the basis for apportionment, the building or heat station needs to determine a heat settlement point, the total heat value apportioned by the household meter. This method is different from the practice of direct measurement and settlement by household heat meters. The use of direct settlement of household meters, the settlement point is determined in each household heating system, located in the building or heat station of the heat meter can not be used for settlement; if the public **** area has an independent heating system, should be considered by whom this part of the heat of the problem.
2.0.7 Room temperature control includes two regulation and control functions, one is the automatic room temperature control, and the other is the human initiative to regulate the said temperature.
3 Basic provisions
3.0.1 This article is mandatory. According to the "People's Republic of China *** and the State Energy Conservation Law," the provisions of the energy-saving renovation of new buildings and existing buildings should be installed in accordance with the provisions of the heat metering device. At present, many projects are only reserved for the installation of metering meters, do not really have the conditions of heat metering, so this article emphasizes the need to install heat metering instruments to promote the realization of heat metering.
3.0.2 This article is mandatory. Heat supply enterprises and end-user heat settlement, heat meters should be used as a basis for settlement. Used for the settlement of the heat meter should meet the relevant national product standards, and metrological verification certificate should be valid in the verification.
3.0.3 "People's Republic of China *** and the State Metrology Law" and other nine articles: the people's governments at or above the county level of the measurement of the administrative departments of the public measurement of standard instruments, departments and enterprises, institutions using the highest measurement of the standard instruments, as well as for trade settlements, safety and security, medical and health care, environmental monitoring included in the mandatory verification of the catalog of measuring instruments for the work of compulsory verification, the implementation of mandatory testing. Not in accordance with the provisions of the application for verification or unqualified verification, shall not be used. The implementation of mandatory verification of the work of measuring instruments catalog and management methods, developed by the State Council. Other measurement standards and work measuring instruments, the use of units should be regularly calibrated or sent to other measurement and calibration institutions, measurement of the people's government at or above the county level should be supervised and inspected by the administrative department.
Based on the "Measurement Law" provides that the heat meter should be used for the heat settlement point of the first inspection and periodic mandatory calibration, not set in the heat settlement point of the heat meter and heat sharing instruments such as radiator heat distribution meter should be in accordance with product standards, with a certificate of conformity and type inspection certificate.
3.0.4 Heat metering and energy-saving renovation work should be used technical and management tools, can not be bent on energy-saving heating, at the expense of indoor thermal comfort, and even cause the room temperature does not meet the standard. Of course, the indoor temperature is too high is unreasonable, in the transformation is not necessary to maintain the original high room temperature.
6 Heat metering technical regulations
3.0.5 Only in the hydronic balance conditions have the premise of climate compensation and indoor temperature control metering in order to play an energy-saving role in the heat source to truly reflect the energy-saving effect; these energy-saving technologies, hydronic balance technology is a prerequisite for the other technologies; at the same time, the indoor temperature control of the existing residential remodeling project is larger, the residents of the life of the disturbance At the same time, the indoor temperature control renovation of existing homes is a large amount of work, and the interference with residents' lives is relatively large, which should be carried out under the premise of energy saving of the external network of the heating system and energy saving of the building envelope insulation.
This article advocates heat metering in the retrofit project first, in order to quantitatively assess the effect of the retrofit, to avoid false propaganda and other behaviors, to encourage fairness in the energy-saving market, and to create good market conditions for energy services. At the same time, while focusing on heat measurement, should also pay attention to the heat source of water consumption, power consumption, sub-metering work.
3.0.6 heat meter selection, not in accordance with the diameter of the pipe directly selected, should be in accordance with the flow and should be selected drop. Theoretically, the design flow rate is the maximum flow rate, in the heating load did not reach the design value when the flow rate should not reach the design flow rate. Therefore, the heat measurement device in most of the working time in the lower than the design flow rate conditions, which according to the experience of this article suggests that according to 80% of the design flow rate selection of heat meters. At present, the heat meter selection, ignoring the flow range of the heat meter, design pressure, design temperature, etc. and the design of the working conditions, not according to the flow range of the instrument to select the heat meter, but according to the diameter of the pipe to select the heat meter, which leads to the heat meter work in the high error zone. Generally expressed heat meter flow characteristics of the indicators are mainly starting flow qVm (some information called minimum flow); minimum flow qVt, that is, the maximum error region to the minimum error region of the transition flow (some information called the demarcation flow); the maximum flow qVmax, rated flow or commonly used flow qVc. Selection of heat flow meter, should ensure that the flow rate is often working between qVt and qVn. Mechanical heat meter flow characteristics.
The flow sensor is installed in the return pipe, is conducive to reducing the ambient temperature of the meter, extend battery life and improve the meter working conditions. At one time there was a point of view that the heat meter installed in the water supply to prevent users from stealing water, in fact, only the water supply to install the meter can not measure the amount of stolen water, but also can not recover much of the loss of water theft, but also to make the heat meter's working environment has become poor.
The provisions of this article stipulate that the heat meter to store the local heating season heating days of the daily heat supply requirements, in order to the heating season operation and management level of assessment and retrospective. In the case of disputes between households and heating enterprises on the heating effect, through the heat meter can be traced and determined, this practice has been a successful case in Beijing; through the outdoor measured average daily temperature records and daily heat supply records of the control, you can assess the actual operation of the heating enterprise in accordance with the meteorological changes in accordance with the initiative to regulate the control of the provisions of this proposal heat meter with data transmission expansion function, but also for the purpose of monitoring, Management and read the meter convenient needs.
Often, in order to meet the requirements of the instrument measurement accuracy, the need to have a straight pipe section requirements. Some places to install the heat meter provides a straight section, but the reducer section is located between the straight section and the meter, this practice is wrong. At present, some heat meter installation does not require straight pipe section can also ensure the measurement accuracy, this way is also feasible, and for the heating system renovation project is very useful. In the instrument manufacturer did not specifically state the history of the case, the heat meter upstream side of the straight pipe section length should not be less than 5 times the diameter of the pipe, the downstream side of the straight pipe section length should not be less than 2 times the diameter of the pipe.
This situation occurred during the pilot test, due to the heat meter clock is not calibrated consistently, resulting in statistical data processing errors, affecting the work, so here to make a reminder.
3.0.7 Currently shoddy thermostatic control valves and balancing valves in the market occupies a high proportion of many manual valves posing as thermostatic control valves, many of the valves do not have pressure measuring holes and measuring instruments are also posing as balancing valves, these shoddy products can not be achieved not only to regulate the function of the control and wasted a large amount of energy, the provisions of this article proposed to require this to be strictly managed.
3.0.8 The current centralized heating water quality problems are more prominent, resulting in radiator corrosion and leakage and regulation of equipment blockage and other problems occur frequently, there is an urgent need to develop a reasonable and feasible standards and strict implementation of the national standard for water quality requirements of the system is being developed.
4 heat source and heat station heat metering
4.1 method of measurement
4.1.1 heat source, including cogeneration boiler room and centralized boiler room; heat station, including heat exchange stations and mixing stations. Measuring instruments at the heat source is divided into two categories, one for trade settlement meter, used for heat production and heat purchasers trade settlement of heat measurement, such as heat station to supply a public **** building and settle the heat bill according to the meter, this must be used for heat meter; the other type of enterprise management meter, used for the calculation of boiler combustion efficiency, statistical output of energy, combined with the measurement of buildings to calculate the loss of pipeline network, etc., where the measurement device is not used for heat Settlement, measurement accuracy can be relaxed, such as the use of orifice plate flowmeter or bend flowmeter to measure the flow rate, combined with temperature sensors to calculate the heat.
7 Heat Measurement Technical Regulations
4.1.2 This article suggests the installation of heat measurement devices in the primary pipe network on the return pipe, because of the high temperature difference between the water temperature, flow rate is small, small diameter, can save investment in metering equipment; taking into account the lower temperature of the return water, it is recommended that the heat measurement device is installed in the return pipe. If the measurement of settlement has specific requirements, should be selected in accordance with the need to measure the location.
4.1.3 In the heat source or heat station, it is more convenient to connect the power supply, it is recommended to use the utility power supply with power failure protection.
4.1.4 Itemized measurement of power consumption at the heat source helps to analyze the composition of energy consumption, find ways to save energy, select and take energy-saving measures.
4.2 Regulation and control
4.2.1 This article is mandatory, in order to effectively reduce the waste of energy. In the past, the boiler room operators with experience, "watching the sky burning fire", but the results are not very good. Pilot practice in recent years found that the waste of heating energy is not mainly wasted in the cold period, but in the beginning and end of the cold period, due to climate change does not regulate the amount of heat supply, resulting in a large amount of wasted energy. Heat supply automatic control device can automatically adjust the water supply temperature and flow rate according to the load changes, to achieve optimal operation and heat supply on demand.
Automatic heat supply control device should be set up at the heat source, which can predict the optimal working condition of the time period according to the current outdoor temperature and the operating parameters of the previous days through the identification of the thermal characteristics of the boiler system and the optimization program of the working condition, so as to realize the operation guidance and regulation of the user side of the system.
Climate compensator is a kind of automatic control device for heat supply, which is relatively simple and economical, and is mainly used in heat stations. It can automatically adjust the heating output according to the outdoor climate change, so as to realize on-demand heating, a large amount of energy saving. Climate compensator can also be set according to the need for time control mode, such as for office buildings, can be set for different time periods of different room temperature requirements, set the normal heating in the office hours, set the duty heating in the off-duty time. Combined with the climate compensator system regulation practice is more and more flexible, the object of monitoring in addition to the user side of the water supply temperature, but also can contain the return water temperature and the indoor temperature on behalf of the room, the object of control can be the heat source side of the motorized control valves, but also can be the frequency converter of the water pump.
4.2.3 The requirement of the water pump frequency control is to emphasize the importance of volume regulation, the previous heating system has been used for many years in the way of quality regulation, this regulation can not be very good to save the pump electrical energy, therefore, the volume of regulation is becoming increasingly important. At the same time, with the application of indoor flow control means such as radiator thermostatic control valves, pump frequency conversion speed control has become an indispensable control means. Water pump frequency conversion speed control is an important part of the system dynamic control, but also an important means of water pump power saving.
Pump frequency control technology has been popularized very quickly, but the pump frequency control technology does not solve the problem of irrational pump design and selection of pump design and selection can not be ignored because of the frequency control.
The pump frequency control technology has been popularized very quickly, but the pump frequency control technology does not solve the problem of unreasonable pump design selection, the pump design selection can not be ignored because of the frequency control and speed control.
The performance curve of the pump using a steep decline in favor of speed control and energy saving.
At present, the frequency conversion speed control mode mainly has the following three:
1 control of the heat station import and export pressure difference is constant: the way simple and easy to implement, but the flow rate adjustment is relatively small, limited energy-saving potential.
2 control network most unfavorable loop differential pressure constant: the way flow regulation is relatively large, energy-saving effect is obvious; but the need for each heat inlet are set up pressure sensors, at any time to detect, compare, control, investment is relatively high.
3 control return water temperature; this way slower response, longer lag, energy saving effect is relatively poor.
4.2.4 The purpose of this provision is to separate the residential and public buildings and other different heat law of the building in the pipe network system to achieve independent time-division regulation and control to save energy. For the system pipe network can be separated from the system, can be separated at the source of the pipe network regulation and control, for can not be separated from the pipe network system, can be in the heat user heat inlet through the regulator valve to regulate separately.
4.2.5 In the past, due to the artificial guarding requirements of the heat station and the increase in investment costs to limit the miniaturization of the heat station, now with the increase in the degree of automation, the heat station has been able to achieve unmanned, and at the same time, the popularity of assembled heat station also makes the investment in a small station and the occupation of a substantial reduction, began to have the basis for the promotion of the popularity of the station. With the continuous improvement of building energy-saving design indicators, especially after the implementation of three-step energy saving in residential buildings, small stations and graded pumps will become an important development direction.