FR2479463A1 - Charge allocation appts. for communal electric heating system - uses counter accumulating weighted sum of individual radiator outputs and links sensors to meter via telephone cable - Google Patents

Abstract

Each apartment served by the system is provided with coulomb counter (1) utilising e.g. electrolysis with soluble electrodes. Each radiator within the apartment is fitted with a semiconductor sensor (7) supplying a temp.-dependent voltage to a processing circuit (5). This delivers a voltage proportional to the excess temp. above a predetermined base value, giving a good representation of the energy emitted by the radiator within its practical temp. range. In the summing circuit (3) the signals from all radiators are multiplied each by a factor proportional to the radiating surface before being added for the instantaneous value of thermal radiation into the entire apartment. The weighted sum is applied via a scaling resistor (2) to the coulomb counter (1) which indicates the total energy consumed since it was last zeroed. A level detector (4) with diodes (8) ensures an excess reading in the event of any attempt fraudulently to isolate or short-circuit a temp. sensor (7).

Description

 In buildings whose heating is provided by radiators, distributors are used to determine the charges incumbent on the various stakeholders.

 The apparatuses of many the most used until now are placed on all the radiators and constituted essentially by a vertical glass tube, closed at its lower end, open at its upper end and qpntenant a liquid whose height is evaporated, this evaporation corresponding approximately to the integration over time of the temperature of the radiator at each instant., a multiplying factor or an appropriate scale obviously taking account of the surface of the radiator concerned.

 These devices have the advantage of very few knives, but they do have various drawbacks, the most important of which are as follows - the liquid evaporates at room temperature.

This phenomenon is particularly regrettable in the current period of energy savings due to the shutdown of heating at night or in mild weather, and also, due to the lowering of temperatures practiced. In addition, it varies depending on whether the evaporators are more or less exposed to the sun.

- non-linear scales, tightened downwards, complicating the readings in the useful part, evaporation slowing down with the drop in the liquid.

- possibility of fraud by the introduction of foreign bodies, gas in particular, considerably slowing evaporation.

 All these drawbacks giving rise to regrettable disputes with users and increasing the difficulties of allocations.

 The distributor object of the present invention, of the same price range as the previous ones, overcomes these drawbacks.

 It comprises: a coulomb counter, a thermistor and a thermomechanical device which ensures its operation only beyond a predetermined temperature, that, for example, of the minimum operating temperature of the radiators.

 Figure 1 below shows how it works.

 The coulomb counter 1, based on Faraday's laws can be, for example, constituted by an apparatus according to the principle of electrolysis with soluble electrodes. In this device a column of mercury lengthens proportionally and linearly with the product of the current which crosses it by the time during which this current circulates.

 The current is supplied by a battery 2 capable of operating at the temperatures of the radiators, which battery flows in a circuit comprising: the above counter, a thermistor 3 which takes coupled or not coupled with a resistor 4, the temperature of the radiator and the thermomechanical switch 5 previously discussed.

 The latter can consist of a bimetallic strip, a dilation system ......, but it can, as a variant, be replaced by a fully electric device corresponding to a Wheatstone bridge (figure 2) powered by a battery, as in the previous case, and whose 4 arms consist of fixed resistors and one or more thermistors.

 The measurement diagonal comprises the coulomb counter, an adjustment resistor 6 and a diode 7 opposing the countdown of the counter when the temperature falls below the predetermined value. The values of the thermistors and of the different resistances are calculated, on the one hand to cancel the measurement current for this predetermined value, and on the other hand so that this current is proportional to the temperature of the radiator considered.

In practice, these various elements are arranged in the following manner which varies with the type of radiator. For Ideal column appliances
Standard, for example, (Figure 3) a good heat conducting block is applied to two consecutive columns. n has two orifices 1. through which pass screws which tighten it strongly on a counter plate (not shown in the figure) placed between the interior columns of the radiator ensuring the fixing of the assembly.

 The cavity 3 is intended to receive the or lesthermistallecs and possibly the thermomechanical device. The lateral grooves 4 allow the fitting of the cover, the lug 5 allows the fitting of the latter and the orifice 6 a sealing.

 The cover, preferably plastic (Figure 4), (seen dc inside) corresponds to this block by its edges 4, its enlboitelnent 5 and the orifice 6 for sealing.

 Y Y are fixed: the coulomb counter 7, the battery 8, a resistor or the printed circuit 9, as the case may be, and a plate 10 indicating on the surface of a radiator, for example 3.5 square meters in the case of the figure.

 All the distributors which differ from each other only by their fixing method have, in fact, identical characteristics. The elongation of the mercury column has been calculated to be as large as possible. It responds, with a small safety margin, to the harshest winters.

 The heat emitted during a heating season responds to this elongation and is related to an area of 1 square meter of radiator. The heat emitted by any radiator therefore corresponds to the product of this elongation x divisions by the surface indicated on the plate 10.

Claims (1)

 - CLAIMS  Device used to determine the heating loads incumbent on each user of a collective boiler room.  Placed on all radiators, this device is characterized by the simultaneous use of a coulomb counter, one or more thermistors and a thermomechanical or thermoelectric device stopping the counting for a determined temperature.