CH637475A5 - Tariff meter for heat consumers - Google Patents

Description

The invention has for its object to provide a counter for heat consumers of the type mentioned in the preamble of claim 1 15 such that it provides a measured value as a tariff counter that loads heat at a low temperature difference between the flow and return comparatively higher than heat at high temperature difference.

20 This object is achieved by the features specified in the characterizing part of claim 1.

In addition, the invention relates to a device defined in the characterizing part of claim 4.

An exemplary embodiment of the invention 25 is explained in more detail below with reference to the drawing. Show it :

Fig. 1 is a block diagram of a tariff counter and

Fig. 2 is a diagram.

In FIG. 1, 1 means a flow temperature sensor which detects the flow temperature Tv of a heat carrier flowing in a flow line to a heat consumer and in a return line to a heat source and outputs a corresponding measured value to a differential element 2. Furthermore, a constant value transmitter 3 outputs a selectable constant value 35, which corresponds to a virtual return temperature Trv, to the differential element 2. If necessary, a return temperature sensor 4 can also be arranged, which detects the return temperature Tr and acts on the differential element 2 via a function generator 5 with the function f (Tr). The differential element 2 forms a measured value, which is related to the flow temperature 40 Tv and the temperature difference

AT = Tv - ^ - f (Tr)

corresponds. This measured value therefore contains a constant component Trv that is independent of the flow temperature Tv and the return temperature Tr.

A flow meter 6, which in the example shown is a volume flow meter, supplies a measured value corresponding to the volume flow V. This measured value, and thus the measured value for the temperature difference AT, are supplied as arithmetic variables to a computing element 7, which calculates the time integral of the product of the arithmetic variables according to the relationship

Q.

t t

= k J V IT dt - k / V - Trv - f (Tr) J

dt or according to another relationship common to heat meters.

In the latter formula, Qv means the one determined by the tariff meter, i.e. the calculated thermal energy, k the heat coefficient of the heat transfer medium and t the time.

The following applies to the actual thermal energy Qf

Q, = k

/ '

V (T

-Tr>

German

For a time interval in which the integrands can be seen as constant, the ratio e between the calculated thermal energy Qv and the related thermal energy Qb

- T

65

e =

rv

- f

<V

- T

3rd

637 475

In the following, with the aid of FIG. 2, two examples clearly show which tariff structure results from the tariff counter described. The solid curve in FIG. 2 represents the course of the ratio e as a function of the return temperature Tr for the case where Tv = 100 ° C, Trv = 40 ° C and f (Tr) = 0, i.e. that the measured value of the temperature difference AT is formed exclusively from the flow temperature Tv and the virtual return temperature Trv and thus the return temperature sensor 4 and the function generator 5 need not be present. It can be seen that at Tr 40 ° C the energy actually consumed, at Tr <40 ° C only part of the energy consumed and at Tr> 40 ° C more than the energy consumed. At high return temperature Tr the curve rises steeply, i.e. there is even a multiple of the energy consumed, which causes the consumer to ensure that the return temperature Tr is as low as possible.

The return temperature sensor Tr and the function generator 5 are required if the tariffing is to be carried out according to less strict standards, as is shown by the dashed curve in FIG. 2. This dashed curve results in 5 if Tv = 100 ° C, Trv = 20 ° C and f (Tr) = ViTr. By choosing f (Tr) accordingly, other curves can be achieved.

In an arrangement of several tariff meters, it is sufficient to provide a single flow temperature sensor 1 and a single io constant value transmitter 3, which are common to all tariff meters. If f (Tr) = 0, i.e. the return temperature sensor 4 and the function generator 5 are omitted, a single differential element 2 common to all tariff counters is also sufficient. It is also possible to provide a single computing element 7 which, in a kind of multiplex circuit, cyclically measures the measured value of the temperature difference AT with the measured values of the various flow meters 6 multiplied and forms the time integral of the product.

G

1 sheet of drawings

Claims (5)

637 475 PATENT CLAIMS 1.Tariff meter for heat consumers who extract heat energy from a heat carrier flowing in a supply line to the heat consumer and in a return line to the heat source, with a flow meter, a flow temperature sensor and a computing element, which are a measured value of the flow and a measured value of a temperature difference related to the flow temperature is supplied and which is designed to form the time integral of the product of these computing variables, characterized in that the measured value of the temperature difference (AT) contains a constant component (Trv) which is independent of the supply temperature (Tv) and the return temperature (Tr). 2. Tariff meter according to claim 1, characterized in that the measured value of the temperature difference (AT) is formed exclusively from the flow temperature (Tv) and a virtual return temperature (T ^. 3. Tariff meter according to claim 1 or 2, characterized in that the flow temperature sensor (1) and a constant value transmitter (3), which outputs a constant value corresponding to a virtual return temperature (Trv), to a differential element (2) and this to the computing element ( 7) are connected. 4. Device with several tariff meters according to claim 3 for heat consumption measurements, characterized in that a single flow temperature sensor (1) and a single constant value transmitter (3) are common to all tariff meters. 5. Device according to claim 4, characterized in that a single differential element (2) is common to all tariff counters. Heat quantity meters are known to be used to measure the heat energy which heat consumers draw from a heat carrier flowing in a supply line to the heat consumer and in a return line to the heat source. These essentially consist of a flow meter, a flow temperature sensor, a return temperature sensor and a computing element, which forms the time integral of the product from the flow and the temperature difference between the flow and return. The suppliers of thermal energy are interested in the fact that the temperature difference between the flow and return is as large as possible, because this results in an optimal utilization of the capacity of the heat pipe network and a maximum efficiency of the heating plant. Consumers are therefore prompted by tariff policy measures to operate the heat consumers with a high temperature difference. Heat meters usually have a flow meter in addition to a heat meter. One could therefore calculate the average temperature difference between supply and return from the measured value of the thermal energy obtained in a calculation period and the measured value of the flow rate and take this into account when offsetting the consumed thermal energy in the sense that consumers who heat their consumers with a low temperature difference between prior - Operate and return, have to pay a comparatively higher energy price than consumers who contribute to a good utilization of the system due to a high temperature difference.