Method and device for control of water flow temperature

FIELD: heating systems.

SUBSTANCE: method comprises control of temperature of at least one of secondary flows of fluid in the secondary circuit which outflows from heat exchanger (1) by means of the primary flow in the primary circuit with the use of control members (5) and (11) that control the primary flow under the action of control unit (7), determining the difference of enthalpies of the primary flow that enters heat exchanger (1) and primary flow that leaves heat exchanger (1), measuring the secondary flow, measuring the flow in the primary circuit, and sending the parameters determined to control unit (7) for control of control members (5) and (11). As a result, the primary flow is controlled by the secondary flow so that the power supplied to the heat exchanger with the primary flow is, in fact, equal to the sum of the power required for the heating of the secondary fluid from the initial current temperature up to the specified outlet temperature, power required for the compensation of energy stored in heat exchanger (1), and power losses from heat exchanger (1). The description of the device for control of water temperature is also presented.

EFFECT: enhanced reliability.

13 cl, 9 dwg

 

The present invention relates to a method and apparatus for temperature control of at least one secondary flow in the secondary circuit, leaving the heat exchanger with the primary flow in the primary circuit through the control element, which may be exposed to from the control unit, this item adjusts the primary flow. The invention also relates to a method for measuring the delivered power and the amount of heat.

During the flow of hot water from district heating installation primary flow centrally heated water down in the heat exchanger, while the secondary flow of hot water heated in the heat exchanger until the temperature constant consumption. In the district installation of heating, the temperature is constant consumption is provided by an automatic mechanical or electronic control devices that regulate the temperature by correcting the difference between the desired and actual output temperature on the secondary side using feedback from temperature measurements on the secondary side. When using electronic control device, typically used proportional-integral or proportional-integral differential is egulatory, which, depending on the current output of the temperature on the secondary side to regulate the flow on the primary side by closing or opening the valve on the primary side. Therefore, in order to obtain a given output temperature of the hot water, thermal effect control on the primary side.

Both mechanical and electronic devices have disadvantages, because the regulation is not as fast as we would like, resulting in a delay may occur before the secondary side will be achieved adjusted temperature. This entails delay reaching the proper temperature at the location of the taps of the secondary side and in the worst case risk of scalding.

Another disadvantage is that when regulating easily vibrations may occur, since in practice it is impossible to optimize regulating equipment for all available operating modes. The temperature of the piping and the pressure in the district heating system, i.e. on the primary side, varies during the year and in the path of the pipeline of the district heating system.

Fluctuations of pressure in the district heating system depends partly on the available distance from the source of heat, partly from the relative location is ogene point of the centralized heat supply system. Statically programmable features regulators cannot be optimized for all common business scenarios, which entails, among other things, fluctuations in the output temperature under certain operating conditions. For example, the following potential disadvantages caused by temperature changes.

Low comfort in the locations of the taps with a small smoothing effect of the pipeline system, especially in private residential households.

Increased calcification of the heat exchangers at a temperature of above 60°C. Increased amortization of regulatory elements.

Harmful cooling of the district heating system, which may entail high operating costs.

From U.S. patent No. 5363905 already known a system in which feedback on the temperature on the secondary side can be used to influence the control valve on the primary side. This solution is adjusted pressure drop on the primary side, but does not maintain the desired rapid correction of temperature fluctuations in the stream of hot tap water on the secondary side. In this case, use the measurement as the pressure drop at the throttle in the primary circuit, and measuring the pressure on the primary side, and the temperature measurement before and after those is labmedica on the primary side. Such a system is relatively expensive, because on the primary side, you need two pressure gauge, and this is not easy to provide a quick adjustment of the temperature on the secondary side for unexpected changes taken on the secondary side of the stream. Adjusting events are not carried out before the actual fall of the temperature on the secondary side, and there are typical fluctuations in the temperature of hot tap water.

In the patent EP 0526884 disclosed method of control for thermal printers, in which the write head is maintained at a constant temperature, first, by regulating the electric power supplied to the printer head, and secondly, by adjustable compensating flow cooler. The temperature of thermal head is measured by the first temperature sensor and the exhaust temperature of the coolant measured by the second temperature sensor. When measuring and regulating the flow of coolant in the device is calculated thermal power, exhaust flow cooler, and measured the temperature of the incoming and outgoing (hot) flow cooler.

From another document WO 96/17210 already known a control device for district heating installation in which one measures temperature and from which irenie flow on the primary side to provide the desired regulation and to calculate the energy consumed with the purpose of billing the consumer. In this case also does not measure the flow rate on the secondary side, which means that the system is likely to experience fluctuations in temperature leaving water on the secondary side.

In the patent DE U 129617756 system disclosed in which shunt regulation is performed on the primary side with feedback on the primary side of the stream exiting the heat exchanger, back to the incoming flow heat exchanger. In this case, it is assumed that, if the temperature of the flow on the primary side of the heat exchanger to maintain a constant, will be achieved at a constant temperature of hot tap water on the secondary side. This assumption is of course entails the existence of temperature fluctuations on the secondary side, since the surface of the heat exchanger must first cool down hot tap water. In addition, the system does not respond quickly to sudden changes in consumption hot tap water, because the adjustment is not carried out until, until you drop the temperature on the primary side.

In the prior art was not considered the need for quick action, when the consumption of heat on the secondary side is abruptly changed, i.e. when the flow rate is changed incrementally. This means that when the oscillations of the system of regulation often stop working, because whereas the temperature on the secondary side. Despite the large number of individual decisions relating to individual problems, there is no system characteristics, providing stable operation regardless of its location in the district heating system. In most systems where it is necessary to precisely adjust the temperature on the secondary side, there are regulatory circuits with feedback information relating to the current value of the temperature, by which is counter to the deviation of the measured value of the output temperature from its set value. Therefore, the effect of such a system depends on the variance of the resulting output temperature. Before can be taken countermeasures, such a system must be in the idle state as long as the deviation cannot be detected, which entails a time delay when the actual specified heat consumption changes.

The task of the invention is to provide equipment for rapid and sustainable management in heat exchange systems in which on the primary side, there may be significant variations in the inlet temperature and differential pressure, in which the best constant temperature at the hot water tap on the side need to change is the customer, in fact, maintaining the temperature constant, is achieved without the need feedback on the value of the actual temperature on the secondary side.

This problem is solved by the characteristics specified in the enclosed claims.

With this invention eliminates the risk of temperature fluctuations on the secondary side, which is in the district heating installation conforms to the contour of hot tap water. Often a district heating installation also has heat exchange circuits for heating and ventilation, are well-suited for this invention. In such systems, the dynamics of load changes is often slower.

Regardless of the amount of consumption of the invention provides improved adaptability to the load. In addition, significantly reduced the risk of calcification in heat exchangers because of faster regulatory systems with higher accuracy can resist temperature peaks above 60°C.

The constancy of the temperature of the hot water tap on the side of the consumer is based on finding the heat output required to improve (alternatively, when cooled to lower temperature of the secondary stream to the specified value. The invention is based is on a dynamic correction of discrepancies between the desired and actual temperatures exceeding secondary environment, which leads to the possibility of the implementation of the regulation without feedback on the actual temperature value on the secondary side.

In most parts of the district heating systems use the invention also entails the ability to install the system without control settings of the adjustment parameters, which significantly reduces the time required for installation and maintenance/tweaking.

In another embodiment, the invention method and apparatus can be applied in case of changes on the secondary side relating to fluctuations in the temperature of the incoming water to be heated in the heat exchanger. This implementation is applicable in the case when the temperature of incoming cold water fluctuates. (In a normal situation it is assumed that the water for the most part has a constant temperature.) With this option, implement the same system can be applied in a larger number of geographic areas, and in the case of another area correction, mainly the possible fluctuations of the temperature of the incoming fresh water, can be done through simple modifications.

In addition, the invention can be used to measure the transmitted power and the amount of heat, such as billing or control energy consumption, and it is also applicable when the hladini, why only change the direction of heat transfer.

Below the invention will be described in the form of a number of embodiments with reference to the accompanying drawings, in which:

figa circuit diagram of the system according to the invention;

fig.1b-d - examples of embodiments of the system of figure 1;

figure 2 - example of a variant of the system with hot tap water and circulation hot water;

figure 3 - example of connection circuit of district heating installation, including regulatory functions of hot tap water and regulation of water for heating, measuring the amount of heat detection differences, warnings, and with means of communication with the control system;

4 is a schematic view of an integrated hydraulic unit for the regulation and measurement of the primary beam according to the invention, includes a valve element, differential pressure gauge, temperature sensor and control element acting on the valve element, which can be integrated in the hydraulic unit or alternatively placed in it;

5 is a cut integral hydraulic unit that performs multiple functions according to the invention, intended for heat exchange circuit; and

6 is a view of the three heat exchangers, each connected to the multi is determined as being the hydraulic unit, interconnected for mutual connection of the primary stream, and with three separate connections for secondary threads, and with a common control unit.

On figa shows an implementation of the invention in the district installation for heating of the consumer. The apparatus comprises a heat exchanger 1 having a primary circuit 3 and the secondary circuit 2. The primary flow 3i, incoming in the primary circuit 3, is formed by the hot water from district heating systems, while leaving the primary flow 3u formed by circulating water. The secondary thread 2i of the secondary circuit 2 is formed of incoming fresh water, heated in the heat exchanger 1, while the secondary exhaust flow 2u is formed is heated, hot tap water supplied to the taps of the ultimate consumer or user. When the temperature of the incoming secondary flow 2i cannot make known in any way (for example, due to the fact that it is constant and known in advance), in the incoming stream 2i enter the temperature sensor (on the figures shown in dashed lines).

In the secondary circuit 2i-2u installed a flow meter 4, it is preferable that he was on the input side, and the flow meter signals are sent to the control block 7. On the primary side in the incoming stream 3i posted by the first temperature sensor 8, and in the reverse flow 3u is aslesen the second temperature sensor 9. Output signals from these sensors are transmitted to the control block 7.

For flow control 3 on the primary side in the primary circuit installed control valve 5, it is preferable that he was in the reverse flow 3u, where lower temperatures and less cavitation load on the valve. The pistons and the valve opening is regulated by a control element 25, which, in turn, receives control signals from the control block 7.

In the shown embodiment, the differential pressure gauge 6 is used to determine flow in the primary circuit 3i-3u, and this manometer is connected between the inlet and outlet holes of the regulating valve 5.

On fig.1b shows an implementation option, similar to that shown figa, but here the control element acting on the primary circuit, formed by the pump 11 with a predetermined dependence of flow 3 in him from the rotation frequency and differential pressure on the pump. The difference ΔP pressure of the pump is measured by the differential pressure gauge 6. Unit 7 controls the pump speed in order to obtain the specified primary flow 3.

Another possible implementation is shown in figs, where regulation of a given flow is performed by measuring the primary flow 3 flow meter 12 and by regulating the degree and opening the valve with the goals of the firm receiving specified primary flow (pay special attention to the local control loop with feedback on the actual flow value).

Variant implementation of fig.1d is a fourth option, in which the flow measurement is carried out through a fixed throttling element 13 and the pressure gauge 6 at the ends, designed for measuring the differential pressure in throttling element.

Figure 2 shows an implementation option, where the primary side of the fresh water input 2i consists of a mixture of cold water and recycled water, the so-called circulating stream of hot water. In this case, is achieved by changing the temperature of the incoming secondary thread 2, for measuring this temperature Tvtorojshould be entered for the temperature sensor 10.

Figure 3 shows a variant embodiment of the invention in the district heating installation, which is responsible for performing certain functions. Examples of these functions include regulation of hot tap water and regulation of water for heating, the measurement of the total amount of heat transferred in a corresponding contour, and also view this information on-line connection to the external control system. It is assumed that the functions of fault detection in heat exchangers and other plant components that are implemented using measured at a set value, and communicate with the dispatching center line are cha is thew functions, carried out by the control block 7. There are sensors for measuring the resulting temperature-facing secondary flows for the purpose of exercising any control and/or alarm when a violation of the functions of the control and/or measuring the amount of heat (in this case, these sensors are not used for dynamic stability temperature).

Basic theory of regulation

The invention is based on the fact that the delivered/absorbed power in the primary circuit must be adjusted relative to the current preset, input/select to/from the secondary environment with the aim of changing the temperature from the current temperature of the incoming secondary stream to a predetermined temperature exceeding the secondary flow. This is carried out by controlling the flow in the primary circuit, depending on the difference between the temperature of the incoming and outgoing primary threads.

In the General case for the primary and secondary circuits of heat exchangers:

where Q' corresponds to the power transmitted by the circuit to the heat exchanger, m corresponds to the mass flow in the circuit, h(T) corresponds to the enthalpy of the environment (energy per unit mass) at a temperature T, Tocorresponds to the temperature of the exit stream and TIcorresponds to the temperature of the incoming stream./p>

Alternatively, equation (A) can be written in the form:

where cp- heat environment, and ΔT=To-TI.

Given the power-Qvtorzheniesupplied to the secondary environment to achieve the desired temperature coming out of the secondary flow, is determined by the equation:

where mDeutcorresponds to the mass flow in the secondary circuit, hDeut(T) corresponds to the enthalpy of the secondary environment at temperature T, TVitaracorresponds to the set temperature of the released secondary flow and Tvtorojcorresponds to the current temperature of the incoming secondary stream.

For heat there is energy balance, in which the amount of capacity supplied to the heat exchanger through the primary side of the Q'firstthrough the secondary side of the Q'Deutand due to any leakage Q'leakagethe heat exchanger is equal to the increase in energy stored in the heat exchanger per unit time, Qvx, that is:

The invention provides control of the power delivered from the primary side, Q'firstso

If the action leakage is negligible, Q'leakagealso on Agout equal to zero, which gives:

During load changes may be appropriate to consider Q'vxthat is determined by the dynamic effect of change of energy stored in the heat exchanger. For example, the system may be controlled by a regulating valve with a relatively low speed adjustment. This will, for example, in the case of rapid load reduction, which means higher power supply primary circuit is compared with the required up until the control will not come to the desired position. Input "excess energy" is partially stored in the heat exchanger and will cause a temporary increase in the temperature coming out of the secondary flow. This temperature rise can be minimized by regulation, which compensates for the excess energy in the heat exchanger by temporary reduction of primary input power up until the excess energy will not be selected secondary stream.

In the steady state, the energy stored in the heat exchanger does not change, then there is Q'vx=0, and introducing this value into equation (B3) gives:

The introduction of equation (A) for the primary side and (A3) into equation (B4) gives:

Removing the mPervyyfrom the level of the ia (S) will provide the basic control principle according to the invention in the form:

This basic principle of management can be assessed in different ways and with varying degrees of approximate simplifications, some of which are shown below. Often the cost is determined in the form of bulk costs, and it is therefore necessary to recalculate the equation (D) for large expenses. For mass flow, m:

where: q is the volume flow and ρ is the density.

Because ρ depends on temperature, it is often necessary to consider the temperature at which the determined volume flow. Suppose that the volume of qDeuton the secondary side is determined on the entrance and given that qPervyyon the primary side is set at the output. After the introduction of equation (E) in equation (D) the resulting equation can be solved relatively qPervyy:

When setting the volumetric flow somewhere else equation (E) shall be applied when the ambient temperature at the place of measurement of the volume flow. For the enthalpy h(T):

where: Cp- the heat (the energy per unit mass by one degree).

The introduction of equation (G) in equation (F) gives:

where: ΔTvtorzhenie=TVitara-Tvtorojand

ΔTfirst=the peruvi-Tpervyh.

When using the same environment in the primary and secondary circuits and neglecting the temperature dependence ρ and (CpDeutfirst;p(dt)=Cp(first)) equation (F2) can be converted to:

Therefore, the invention can be assessed in several more or less approximate methods (e.g., through regulation according to the equation D, F, F2 or F3). Common to them is that they are based on the array of parameters, characteristics of the difference (Δ (h) the enthalpies of the primary beam (3i), which is included in the heat exchanger (1), and the secondary flow (3u)emerging from the heat exchanger (1), for example, on the number of points of the function h(T) for the primary environment in the temperature range typical applications, and TpervyhTperuvi. An example of an alternative characteristic parameters array instead of the specified difference of enthalpies is formed by heat withpthe primary environment in a temperature range that is relevant to the application area, and the difference ΔTfirsttemperature.

According to the invention similarly you can use other characteristic parameter arrays instead of the mass flow (mDeut) in the secondary circuit (2) and massive spending is a (m first) in the primary circuit.

The design of the control valve

The valve 5 may be different for specific design must be known characteristics of the flow. Examples of valves include truck, spool, ball and Poppet valves. When using the spool valve, which opening/closing is actuated by the adjusting screw, the biggest opening of the valve is essentially proportional to the move.

Depending on the current drop ΔPvalvepressure, flow, qvalvethrough the valve and the degree and opening the valve to the valve of each type you can determine the characteristic of kv(a). Therefore, the flow through the valve is determined by the ratio:

of which may be found:

and

where: fcv(x) is the inverse function of kv(x).

Function control valve with measuring differential pressure

During use of the valve the valve position control in order to achieve the adjusted flow rate. Each valve type can be determined empirically achievable flow rate on the basis of the current valve position and pressure drop across the valve.

The position of the valve, and needed the second to regulate, can be expressed in dependence on the measured flow rate in the secondary circuit, the measured temperature difference on the primary side, the measured differential pressure regulating valve and a given temperature difference in the secondary circuit.

For each of the specified flow in the primary circuit adjusts the valve position can be carried out according to the equation:

on the basis of which after the introduction of equation (F) in equation (J2) gives the expression for the control principle according to the invention:

or after injection (F3) in (J2):

since the same fluid is used in the primary and secondary sides, and since the temperature dependence ρ and (Cpis negligibly small. For each valve can be determined empirically reverse current characteristics of the flow fcv(x) (and/or characteristics of the consumption of kv(x)).

It is assumed that the determination of the pressure drop ΔPvalvecan be performed by an arbitrary method, for example, by a differential pressure gauge connected upstream and downstream from the valve, or by the first absolute pressure gauge for measuring the pressure P1 upstream from the valve and another AB is autogo manometer for measuring the pressure P2 downstream from the valve.

Measurement of power and a quantity of heat

Based on equation (A), the measurement of input power and a quantity of heat can be done on the primary side and/or on the secondary side of the heat exchanger. After inserting into equation (A) equations (H) and (E), applied to the medium in the valve, we obtain:

where: Tpervan- the temperature of the primary environment in the valve.

If the valve is placed in the primary flow (3u)emerging from the heat exchanger, Tpervan≅Tpervyhand accordingly, if it is placed in the primary flow (3i), a part of the heat exchanger, Tpervan≅Tperuvi.

After inserting equation (G) in equation (L) is an alternative equation:

In accordance with the preferred embodiment, the electric power applied to the primary side, is partly by determining the temperature TperuviTpervyhand pressure drop ΔPvalveon the regulating valve placed downstream from the outlet of the primary side; and in part using information about the characteristics of kv(a) and the extent and the valve opening, and the density and the enthalpy of the initial environment, whose values are used to calculate Q'firstin accordance with sravnenie (L), alternatively, in accordance with (L2).

By integrating the power delivered during the time interval t1-t2, we obtain the amount of heat supplied to the primary circuit during this interval:

Equation (L), inserted in equation (M), gives:

The integration can be performed, for example, by determining and summing up one after another of the partial energies, this energy set as works periodic average powerand the corresponding time intervals for the formation of the average value of Δti:

In accordance with a preferred embodiment of the invention the output power and the amount of heat can be determined also on the secondary side. In this case, the definition is based on the temperature Tvtorojand Tvtoroy(measured by the fourth temperature sensor and the flow rate value qDeut(measured by the flow sensor or determined by other means, for example, by the known characteristics of the pump with variable speed) and equation (A).

Assuming steady state and negligible leakage of heat from the heat exchanger is given power and quantity is of warmth on the primary side form a first indicator, and the value of the given power and the amount of heat on the secondary side form a second power index Q' and the number Q heat transferred in the heat exchanger. You can use one or the other of these two independently defined metrics given power and a quantity of heat, for example, for billing or control energy consumption.

By comparing these two independent metrics to system reliability can be enhanced. For example, a high value of Q' can be used to get a warning signal that the indicators are not reliable, if these figures differ from one another by more than the allowable value, such as ±10% or preferably on ±2% higher values.

The second application may be switching any way system in a redundancy mode based on the definition of Q', provided that the error of the measuring signal, which is included in the definition of Q' in accordance with another method, is another independent way. Example: if defined, for example, by checking for consistency, that the temperature sensor on the primary side is corrupted, it is possible to determine a substitute value for a bad sensor by using the values of Q'defined naverezhnoi side. Similarly can be computed backup value for any sensor error which is detected by an independent method.

A third application may be self-calibration of the sensor or, for example, using the same manner of the characteristics of the valve for the calculation of reserve values in case of sensor failure.

Integral valve nodes

To simplify manufacturing and Assembly systems according to the invention, in a preferred embodiment, several functions can be jointly implemented in the integral valve site, which can be manufactured as semi-finished product for further integration with the formation of the completed system. Figure 4 schematically illustrates the integrated hydraulic unit designed to control and measure the primary beam according to the invention, includes a valve element, differential pressure gauge and temperature sensor, and a control element acting on the valve element, which can be integrated in the hydraulic unit or alternatively installed in it. This hydraulic unit can advantageously be used to control the primary flow and the measurement of the differential pressure on the valve element and the temperature of the primary flow at the valve.

Several functions/components can be attached to the hydraulic block 40, shown in figure 5, containing the first channel 56 between the sleeves 41 and 42 for pipes intended for connection respectively to the district heating system and to the heat exchanger and discharge pipes 43 and 44 to any neighbouring additional hydraulic units; see Fig.6.

In the channel 56 posted by valve element 53, which is controlled by a control element 54. The gauges 61 and 62 are installed on both sides of the valve element 53 to measure the differential pressure upstream and downstream from the valve element. In the channel 56 also has a sensor 8 for measuring the temperature of the medium in the channel 56. In the hydraulic block 40 is made of the second channel 57, and the channel through the clutches 45 and 46 for pipes can be connected respectively with the input environment of the district heating system and heat exchanger. Discharge pipes 47, 48 from the second channel 57 may be used to join adjacent additional hydraulic units. In another channel 57 is also posted by the sensor 9 for measuring the temperature of the environment in this channel. Part of the hydraulic unit 40 are also third and fourth channels 58 and 59 with the sleeves 49 and 51 for pipes intended for connection to a consumer, heat/cold, and couplings 50 and 52 for pipes to the heat exchanger. For measuring the temperature of the medium in the channels 58 and 59 in the respective channels placed sensors 55 and 10. To determine the flow rate in the channel 59, a pressure gauge 70. Provided contact elements (not shown) for connecting communication lines to and from the hydraulic unit 40, which is transmitted measurement data and/or control signals.

Integral hydraulic unit of figure 4 can be achieve the benefits made in the form of semi-finished product for further integration with the formation of a complete system, for example, shown in Fig.6. The use of hydraulic units provide potential advantages in addition to those already mentioned due to a significant simplification hosting and joining the primary and secondary circuits.

In most typical embodiments, the temperature of the secondary thread 2 exiting the heat exchanger 1, is constant, for example, 55°C. of Course, you can manually or automatically set to the specified value. For example, the preset value can be set using the potentiometer in the control block 7. Some manual adjustment can be made depending on the wishes of consumers of hot water or to make it depending on the current season of the year. For example, during the winter may require more heated hot tap water to compensate for loss of heat between the heat exchanger and the pain is it part of the remote users. Correction depending on the season the temperature of the exit stream on the secondary side can also be done automatically by the control unit in accordance with a predetermined curve compensation and/or signals from external temperature sensor.

In one application of the invention in a system in which the heat exchanger heats the heating circuit, the corresponding correction in most cases necessary, depending on the outside temperature, and the correction of the temperature of the incoming secondary flow. In this embodiment, there is no need for immediate feedback on the temperature of the exit stream on the primary side.

Control elements for regulating the valve can be of several different types, and each receives a control signal that is appropriate for the control element. For example, can be used for valves with servo motor controlled by pulse-width modulation (PWM), or by regulation of the flow rate is proportional to the managing current and voltage.

The method in accordance with the invention can advantageously be combined with the detection of malfunctions in the heat exchanger. In those variants of implementation, which measures the differential pressure across the valve, the initial contamination on the primary side is e (caused by deposits of calcium, dirt, etc. can be detected by analysis of the pressure drop with time for a given amount of valve opening. During the initial contamination of the pressure regulating valve is decreased when the flow rate remains constant, because the increasing pressure drop will campfireusa heat exchanger. Fault detection can also be done on the evaluation of the heat exchanger. For example, you can use the following method: all the measured signals (at least the temperature difference in the primary circuit, the primary flow secondary flow and the desired temperature difference on the secondary side) retain for a number of different load modes (transmit power) and regimes (temperature and pressure of the incoming primary flow). When the clogging of the heat exchanger heat transfer characteristics deteriorate, which entails the need to increase primary threads.

The required difference ΔTfirsttemperatures can be calculated on the basis of Tperuviand Tpervyhor by directly measuring the temperature difference, for example, a thermocouple.

Because the system is measured as flow rate and temperature difference, it is possible to easily calculate the consumed amount of heat for billing destination is POTREBITEL.

In addition, the system is well adapted for readings (calculate the heat transfer), fault detection (contamination), climate regulation (with a centralized installation of specified values) and possible termination of operation. For lines of communication need only one interface, and this interface is connected to the control unit or regulation.

The invention is not limited to use in district heating installations; it can be used in all areas where the heat exchangers are part of, for example, in the petrochemical industry or in systems heat control other species.

1. Method for controlling temperature of the at least one opening of the secondary flow (2u) in a secondary circuit of the heat exchanger (1), by the primary flow (3) in the primary circuit, and the unit (7) controls regulating element (5, 11), which regulates the primary flow, and the temperature TDeut. Ifacing the secondary flow is known or should be measured, characterized in that

a) define an array of parameters, the characteristic difference (Δ (h) the enthalpies of the incoming primary flow (3i) in the heat exchanger (1) and facing the primary beam (3u) of the heat exchanger (1),

b) define an array of parameters characteristic of the mA is spot flow (m Deut) in the secondary circuit (2),

c) define an array of parameters characteristic of the mass flow (mfirst) in the primary circuit (3),

d) and the fact that the parameters defined in paragraphs (a) through (C), passed in unit (7) for the control of the regulatory element (5, 11), resulting in the primary flow (3) is adjustable depending on a secondary thread (2) so that the power transferred to the heat exchanger of the primary flow (3)essentially corresponds to the sum of:

1) the power required to raise the temperature of the secondary environment from the current input temperature TDeut. Ito the desired output Temperature TDeut. o. setand

2) the estimated power required to compensate for the accumulated energy in the heat exchanger (1), and

3) assumed power leakage from the heat exchanger.

2. The method according to claim 1, wherein the regulatory element is produced through the coordination costs of the primary flow (3) against the secondary flow (2) in a way that preserved the balance of energy between the primary flow (3) and a secondary stream, with input and power consumption in the corresponding circuit flow is:

Q=ρ·Cp·q·ΔT, which gives the energy balance, and this flow qfirston the first the primary side reach through control so to:

ρsecond/first- pre-defined density of the medium, respectively, in the secondary and in the primary circuit,

withp(second/first)- pre-defined specific heat of the medium, respectively, in the secondary and in the primary circuit,

Qfirstthe flow in the primary circuit, the resulting action control,

qDeutactual measured flow rate in the secondary circuit,

ΔTfirst- the actual measured temperature difference between the incoming and outgoing media on the primary side, and

ΔTDeutis the desired temperature difference between the incoming and outgoing media secondary side, while the temperature on the outlet side of the secondary circuit is the specified value, resulting in the control of the regulatory element is carried out without direct temperature feedback on the output side of the secondary circuit.

3. The method according to claim 1 or 2, characterized in that the braking element (5) is represented by the regulating valve with the known characteristics of the flow and the pressure difference (pressure drop) on the regulating valve, the measured differential pressure gauge (6).

4. The method according to claim 3, characterized in that the degree (a) opening the valve which is a function of preferably empirically certain reverse the flow characteristic of the valve f cv(x)in accordance with the following:

where ΔPvalve- the measured differential pressure regulating valve, qpri. specifiedthe flow through the valve and the degree of valve opening.

5. The method according to claim 1 or 2, characterized in that the braking element is represented by a pump (11) with a predetermined relationship between the flow through it as a function of speed and pressure drop across the pump, resulting in unit (7) control adjusts the pump speed.

6. The method according to claim 1, characterized in that the measured temperature (TDeut. Ithe incoming secondary flow (2i) in the heat exchanger (1), and this measured value is used to calculate the qpri. specified.

7. A device for controlling temperature of the at least one opening of the secondary flow (2) from heat exchanger (1) in the secondary circuit through the primary flow (3) in the primary circuit, passing through the heat exchanger in this unit (7) controls regulating element (5, 11)established for the control of the primary flow, characterized in that the sensors (8, 9) temperature to measure the temperature of the primary threads in (3i) and out (3u) heat exchanger (1), to determine the difference of the enthalpies of these flows, establish the flow meter (4) in order to measure the flow rate (q Deutsecondary environment (2)install differential pressure gauges (6) for measuring the difference (ΔP) pressure in the primary environment (3i) on the regulating element (5), and/or the fact that installing the flow meter (12) for measuring the flow rate (qfirst) primary environment (3), and those that organize the transfer of the output signals from these sensors (4, 8, 9, 12) to the block (7) to control the regulating element (5, 11), resulting in the possibility of control of the primary flow (3) depending on the secondary stream (2), so that the power transferred between the heat exchanger and the primary flow (3)essentially corresponds to the sum of:

1) the power required to raise the temperature of the secondary environment from the current input temperature TDeut. Ito the desired output temperature TDeut. o. setand

2) the estimated power required to compensate for the accumulated energy in the heat exchanger (1), and

3) assumed power leakage from the heat exchanger.

8. The device according to claim 7, characterized in that the braking element (5) is represented by the regulating valve with known characteristics of flow, differential pressure gauge (6)is installed to measure the pressure difference across the valve, and known characteristics of the flow valve (5), memorized remember in the third unit block (7) of the control.

9. The device according to claim 7, characterized in that the braking element is represented by a pump (11) with a predetermined relationship between the flow through it as a function of speed and pressure drop across the pump, resulting in unit (7) control provides adjustment of frequency of rotation of the pump.

10. The device according to claim 7, characterized in that the valve (5) is integrated in the hydraulic unit (20)containing a valve element (24) with a control element (25)acting on it, clutch (22, 23) for pipes connected to the valve (5), the device (6) for determining the differential pressure on the valve element, which is connected upstream and downstream from the valve element (24), sensor (8) temperature, which determines the temperature of flow through the valve.

11. Device according to any one of claims 7 to 10, characterized in that the block (7) control contains at least one mass storage device (30) for storing the degree (a) opening the valve (5) as a function of flow qDeutthe secondary circuit (2), difference ΔTDeuttemperature in the secondary circuit (2), difference ΔTfirsttemperatures in the primary circuit (3) and drop ΔPvalvepressure valve (5).

12. The device according to claim 7, characterized in that the hydraulic unit is made channels (56-59) for a conducting medium (3i 3u, 2i, 2u) in and out of the heat exchanger (1), the fact that ethically at the ends provided with a clutch (41, 42, 45, 46, 49, 50, 51, 52) for pipes for connecting the primary and secondary streams (3, 2), the fact that the transverse channels (43, 44, 47, 48) allocated from at least some of these channels, while the transverse channels at the ends of similarly equipped with couplings for pipes to attach the connecting pipe between several connected hydraulic blocks, and the fact that the hydraulic unit are lots of channels for sensors(8, 9, 10, 55, 61, 62) flow rate, differential pressure and temperature, are in communication with channels and at least one control valve.

13. The way to increase the reliability of the system heat exchanger (1)containing at least one secondary thread (2) in the secondary circuit and the primary flow (3), unit (7) controls regulating element (5, 11), which regulates the primary flow (3), which determines the difference (Δ (h) the enthalpies of the primary flow, which is included in (3i) and out (3u) heat exchanger (1), determine the pressure difference (ΔPregulatory element) and temperature (TenvironmentIn regulating element (5, 11) with known characteristics of consumption stored in the storage unit (7) control, maintain the density of the primary environment in the storage unit (7) control register the difference (Δ (h) enthalpies, the pressure difference is s (Δ Pregulatory element), temperature (Tenvironment) and the degree (a) opening of the regulating element, and these values together with the characteristics of the flow and density remain in a storage device of the control unit, ensure the power measurement and the quantity of heat given to the primary circuit, characterized in that simultaneously compare the received power measurement and the quantity of heat given to the primary circuit, with the true power values and the amount of heat absorbed by the secondary circuit, which is calculated on the basis of indicators of a difference (ΔhDeut) enthalpies of input and output of the secondary flow and the secondary flow mDeutstored or determined in the control unit, resulting in the environment through means of communication is issued alarm if the power value and the amount of heat delivered and absorbed, respectively, the primary and secondary circuit, deviate from one another by more than a predetermined allowable value.



 

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