FR2473158A2 - House heating system using heat pump - uses modified operating system, relating external temp. with water temp. at selected parts of circuit - Google Patents

Abstract

The heating system for a house, using a heat pump with an underground heat exchanger coil and solar heating, as in the main patent, is modified by maintaining a relationship between the external temperature, the temperature of the water passing through a control valve, and in the storage tank and that leaving the condenser. This relationship can be expressed by a simple formula. The continuous control system is replaced by a monitoring at selected intervals, of selected temperatures. The heat pump is operated only if the temperature in the lower reservoir vessel is at the control temperature or the temperature is too low at the start of heating up. Part of the automatic control is replaced by manual control.

Description

 The present addition to the patent filed on December 7, 1979, concerns the equipment control system (motorized valves and heat pump in particular), the use of the set temperatures in the servo-control of said equipment, and various improvements intended to facilitate the circulation of the equipment. coolant.

The object of regulation is twofold:
- allow, on the one hand, to provide heating in optimal comfort conditions, through the provision of external mechanical energy, but without any recourse to a thermal energy not free;
on the other hand, to reduce as much as possible the quantity of mechanical energy consumed, by obtaining the smallest possible difference between the outlet temperatures of the condenser and the evaporator, when the intervention of the pump heat is necessary.

 This dual purpose could lead to the setting up of a regulation resulting, by its initial cost, too heavy loads for the equipped facility. It is therefore necessary to specify the characteristics of the regulation compatible with each case studied.

 The present addition is written keeping the hypotheses formulated in the patent (climate, building, heating conditions, etc.).

This is only an example intended to facilitate the understanding of the system described, and the principles remain valid in all cases.

Two boards are attached
- The 1/2 board is the reproduction, identical, the single board of the brevet.Elle is essential to the reading of this addition, all notations of the patent have been preserved.

 - The 2/2 board is a partial production of the diagram (plate 1/2) lightened and modified to present the various variants described below. Only a few notations are added.

 Small tanks 90 and 97, often referred to as "equilibrium cylinders", are intended to facilitate flow variations and flow reversals resulting from the control action.

 - The pipes 98 and 99 replace the pipe 12, on either side of the bottle 97.The piping 89 replaces 74.The pipes 17 and 95, previously connected to the tank 11, result in a bottle 20, connected to the tank by a tube 201.

 The temperature td, necessary at the start of the heating installation, is a function of the outside temperature te, and can be considered, in practice, as a linear function of it.In the patent, the accepted relation is td = 32.3 - 0.65 te .Specific values can be useful.They will be called tdl td2 ... and will correspond to the values te2 .. of te.

 The motorized valve 53 of the sensor circuit obeys two different laws in summer and winter.The law, in summer (minimum temperature at the output of the sensors) will vary according to the climate and the installation.In winter, this law ( related notably to the detection of an increase of the water temperature in the sensors X will be a function of the technology of the comparison device and the inertia of the sensors.

 The valve 92 is slaved to the temperature of the water, coming from the sensors, which passes through it, with a set temperature t.sub.This temperature tc will obey td according to a linear function, and consequently to te always linearly. setpoint tr (tank 11 - socket 96) and tp (regulation at the start of condenser 72) will obey a linear function of te.If the regulation has a discontinuous effect, the values tel, te2 ... etc will correspond, for a given installation values tci, tri, tpi tc2, tr2, tp2 ... etc.

 Since such a servo-control is likely to lead to too frequent variations in speed, it may be useful to choose a periodic basis, and, for example, a daily basis which will define the setpoint values for the day. This base may be the daily minimum tm recorded at fixed time (4.5 or 6 hours depending on the statistics). In this case, the set values of tc, tr, tp (but not td) will be related to tm, instead of te, and according to a different law.

In the example of the patent, the laws could be, in case of continuous variations:
tc = tr = 28 - 0.5 te and tp = 32.5 - 0.625 te with minimum values of 280 for tc and tr, and 30 for tp, or:
tc = tr = 30 - 0.5 ts and tp = 32.5 -0.625 tm with the same minima.

If the variations are discontinuous, the values could be
tc tr tp
t> +4 28 28 30
+4> ti b 0 30 30 32.5
O> t. 32 32 35
The setpoint value of tc controls the position of the valve 92. The setpoint value of tp controls, according to a fork linked to the equipment used, located on and off the compressor, when the heat pump is authorized to operate, and only in this case.This permission is granted if tr is less than the setpoint value, if the regulating valve 18 td is at the end of stroke, mitigeage closed, which would mean that the regulation is no longer ensured, the temperature in the reservoir , being too weak.

The regulation will therefore work as follows:
- The setpoint values of tc tp and tr are set according to one of the stated rules (continuous or non-continuous variations, variable te or tn depending on the installation)
- The water from the sensors flows according to the position of the valve 92, related to the temperature of this water with respect to tc.

 - The heat pump is at a standstill if the temperature at 96 is higher than the set point of tr, and if the valve 18 is not at the end of the stroke (mitigating closed).

 - The heat pump can operate if the temperature at 96 is lower than the set point of tr, or if the valve 18 is at the end of stroke. It is then regulated at the set temperature tp.

In the case of an installation the importance or nature of which
No justification for such a regulation, the device will be simplified, either by passing to a discontinuous regulation, with reduction of the number of set points, or by passing to a manual regulation.

As an example of possible simplification:
- we will adopt a single set point for tc (280 in the example) with a manual change to full open on 94 when you are less than or equal to +40
- we will choose for tr two setpoints, 30 "normally and 320 when you are less than + 40, with manual passage
- the heat pump will be permanently set at 350.

 This will result in a loss of the heat pump's coefficient of performance, and the mechanical energy consumption will increase by 5 to 10%, which may be less than the realized damping economy.

 It is possible that the installation is regulated by means of a room thermostat acting on the valve? 8.It remains then possible to apply the simplified arrangements which precede, but also to preserve an automatic regulation by enslaving tc tp and tr at the values of td found on line 12 (after mitigating), and taking certain precautions (tp substantially greater than td, and, if the regulation is discontinuous tc and tr slightly higherYA td.

 A number of improvements to the diagram of the board 1/2 are further likely to facilitate the operation of the control system thus defined.

 It is possible to connect the pipes 17 and 95 to a bottle 20, connected elfe-m8me to the tank 'Il by a tube 201 of large diameter, according to drawing of the board 2 / 2.Similar, when the flow rates are equal in 17 and 95, the flow rate in 201 will be zero, and the sensors are powered exclusively by the return water from the heating, at minimum temperature, without any risk of mixing. If one of the pipes is to have a reduced flow, or no, the pipe 201 ensures the flow of the difference, in the desired direction, the relative pressure conditions being such that the water from 17 passes in priority in 95.

 It is also possible, and will often be desirable, to have at the intersection of lines 94 75 and 76 an equilibration bottle whose rssle will be effective when the valve 92 is open in the direction of 94. When the pump 73 rotates ( compressor running) the water will flow normally to the condenser.But upon the cessation of the pump 73 circulation in the condenser circuit is braked, if not interrupted, and a pure and simple tapping may cause the flow of the water to the reservoir, which is in relative depression. The bottle 90 overcomes this difficulty.

 Finally, it is possible to modify the diagram of the plate 1/2, according to the characteristics of the installation, and especially of the tank 11, in order to improve the stratification of the heat in it.This purpose will be achieved by connecting the pipe 73 no longer on the tank 11, hands on the start of the heating (previously 12, this notation being replaced in the 2/2 board by 98.97, and 99, the bottle 97 being inserted in the tank-98 circuit and 99-mitigeage.

The water coming from the heat pump (maximum temperature at this moment) then passes directly into the heating circuit, without its passage in the tank being likely to cause a diffusion in the water oins hot. The excess water, possibly as a result of the action of the mixer 18, then flow back to the tank. When the heat pump is turned off, on the contrary, the tank will supply, as required, the pipe 98.

 In the three devices described above, the circulation is carried out sometimes in one direction, sometimes in the other, inside the pipes 98 75 and 201.Il will be useful that the diameters of these pipes are widely dimensioned, so that the water velocities entering the reservoir are as low as possible. In addition, conventional systems designed to minimize the risks of mixing introduced and stagnant water should be used.

Claims (10)

RSWENDICATIONS  1. Device according to claims 1 and 8 of the patent, characterized by the definition of a simple mathematical relationship between the tem each external temperature te (variable selected) and / d> s tc setpoint temperatures (applicable to the temperature of the water passing through the valve 92), tr (applicable to the temperature of the tank 11) and tp (applicable to the regulation of the temperature of the water leaving the condenser), the setpoint temperatures tc, tr and tp being thus enslaved continuously, thanks to simple and known solutions, the temperature te.  2. Device according to claim 1 above, characterized in that the continuous servocontrol is replaced by a discontinuous control, a number of limit temperatures tel te2 etc ... determining the values assigned to the set temperatures, either , respectively, tct, trl, tpt tc2 tr2 tp2 etc ...  3. Device according to claims 1 and 2 above, characterized by replacing the variable te (external temperature of the instant), replaced, with appropriate modification of the mathematical relations, for one of the three setpoint temperatures. tc, tr, tp, for two of them, or for all three, by the probable minimum temperature of the day tm, admitted and arbitrarily measured by reference to the usual evolution of the temperatures in the studied climate.  4. Device according to one of the three claims 1,2 and 3 above, characterized in that the operation of the heat pump (always under the control of the tp command) is only possible if one both of the following conditions are met:  - temperature in the tank lower than the set temperature, or  - insufficient temperature at the start of the heating (can be signaled, for example, by limit switch on valve 18).  5. Device according to one of claims 2 and 3 above, characterized by the replacement of the automatic servocontrol (electronic, pneumatic or other) by manual interventions, the operator adjusting the three setpoint temperatures (or only one or two of them) according to a table of correspondences based on the instantaneous external temperature, or on the probable daily minimum (te or tone).  6. Device according to claims 1,3,6,7 and 8 of the patent, characterized by the application of the types of regulation described in the above reports to installations whose automatic adjustment does not depend on the outside temperature , but, for example, of a thermostat of room, the variable then being the instantaneous td heating temperature (rev.l and 2 above), or the maximum starting temperature of the day tdm (rev .3 above) or even td and tdm used jointly or not (see 5 above), instead of te or tm, the rules of servo or correspondence being adapted accordingly, depending on the technology of the regulation of the heating, and possibly reduced to a simple arithmetic difference between the variables and the enslaved temperatures.  7. Device according to claim 1 of the patent, characterized by the existence of an equilibrium bottle receiving the connections of the return of the heating and the flow to the sensors, bottle connected to the lower part of the tank by a largely sized piping , in which the direction and the importance of the circulation will depend mainly on the flow of the two preceding pipes.  8. Device according to claims t and 7 of the patent, characterized by the existence of a balance bottle on the return of the tank to the condenser, bottle to which will be connected the pipe coming from the three-way valve previously simply stitched on it return, bottle intended in particular to facilitate the flow of water from the three-way valve to the tank, when stopping the heat pump.  9. Device according to claim 1 of the patent, characterized by the connection of the flow of the heat pump (condenser) not on the tank, but directly on the start of the heating.  10. Device according to claim 9 above, characterized by the existence of an equilibrium bottle placed at the connection point of the condenser outlet on the heating outlet, bottle intended in particular to facilitate the possible reversal of the circulation of water between the reservoir and the connection point, possibly resulting from the regulation technology used.