DE3332020A1 - Process for the operation of an absorption heat pump in direct heating operation, and absorption heat pump - Google Patents

Abstract

The invention relates to absorption heat pumps which are alternatively also operated as boiler heating systems in order to obtain higher feed temperatures. The object of the invention is to increase the hitherto attainable feed temperatures, to develop an improved process for a heat pump working in direct heating operation, and to provide a corresponding system. According to the invention a process is described in which the vapour given off, directly and with little reduction in pressure, and the degassed solution, with a likewise small reduction in pressure, are passed into the absorber to give up heat.

Description

Title of the invention

Method for operating an absorption heat pump in direct heating mode and an absorption heat pump system

Field of application of the invention

The invention relates to alternatively as a heat pump or · absorption heat pumps operated as boiler heating for heating a heat transfer medium for heating systems and for? / poor water preparation and affects how it works in direct hot operation

Characteristics of the known technical solutions

Absorption heat pumps designed to meet peak demand or the heat demand at low outside temperatures without arranging an additional heating system in direct heating mode work are known. This is done in direct heating mode the supply of working medium to the absorber is interrupted and the solution heated in the expeller is directly transferred to the absorbent fed and cooled in this in heat exchange with the heat transfer medium of the heating system and then the Expeller supplied and reheated · Pur the mixed heat pump / heating operation continues a method is used according to which the absorber substance is at least two different, non-reactive with one another Contains working materials that have significantly different vapor pressures,

The well-known absorption heat pumps designed for alternative heat pump or direct heating operation are disadvantageous insofar as in particular from the point of view of the control of occurring pressures, the liquid transport and the size of the heat exchanger surfaces requires a considerable outlay in terms of equipment

To avoid the disadvantages mentioned, a method for operating an absorption heat pump has already been used as Boiler heating proposed in which the expelled working medium is passed into the evaporator, where it is liquefied and stored * The absorption heat pump works as a boiler heater by now essentially after increasing the heat supply to the expeller Vapor consisting of solvent is generated »which gives off heat to the heating network in the condenser partially condensed and fully condensed in the absorber · Requires use to achieve high flow temperatures of steam as the sole heat transfer medium, a very low concentration of solution in the expeller in order to to be able to achieve high condensation temperatures in the condenser and absorber, which in the end with very large expenditure on equipment is connected · A further suggestion is the protection claim directed a method, according to which the circuit after the separation of the working medium consists essentially of solvent existing liquid is supplied, whereby the solution concentration in the expeller is lowered and the The condensation temperature of the steam in the condenser and absorber is increased *

The required increase in the solution concentration also requires a high level of additional equipment and expense Tax and regulatory expenses

Object of the invention

The aim of the invention is to improve overall economy absorption heat pumps operated as boiler heating

Explain the essence of the invention

The invention is based on the object of known methods to operate absorption heat pumps as boiler heating and to develop a corresponding device to provide that while avoiding increased expenditure on equipment, substantially higher flow temperatures can be achieved and the primary energy consumption for Operation of the system can be reduced

According to the invention, the object is achieved in that the steam expelled in the expeller is fed directly to the absorber with a slight pressure reduction, which in the extreme case corresponds to the pressure loss in the connecting pipes between expeller and absorber, and the poor solution from the expeller to the Depending on the pressure and the concentration of the solution in the absorber, the absorption takes place at a temperature which is only slightly below that in the expeller. According to a further feature of the invention, the expelled vapor is passed over the condenser and partially condensed there. In this way, different heat emissions, e.g. for hot water preparation and for the heating system, are achieved.
In a further embodiment of the invention, the expelled working fluid vapor is separated from the circuit and stored before the direct heating operation starts.This means that a lower concentration solution is available so that higher steam temperatures can be reached and the flow temperature can be increased further Equipped with a bypass line between the expeller and the absorber or between the condenser and the absorber and another bypass line in the solution circuit.

The bypass lines are provided with throttling devices or dimensioned in cross-section so that the required pressure difference compared to the pressure in the expeller is achieved This makes it possible to set the temperature of the heat emission · The pressure reduction can also be over the already Expansion devices that are present in the system, but are adjustable, are effected according to the invention a solution pump is used, the output of which can be reduced in direct heating mode · This reduces the electrical energy consumption for operating the solution pump and the economy of the heat pump working in direct heating mode is further improved. The technical teaching according to the invention does not apply to the known teaching Solutions for the direct heating operation of absorption heat pumps ζω? Increase in the heat output a required effort considerable increase in the flow temperature possible · Advantageously, in the method according to the invention Both the steam and the solution are used as a heat carrier, increasing the efficiency of the heat pump in direct heating mode is decisively influenced · At the same time, there is an improvement in the utilization of the heat exchanger surfaces recorded so that more heat can be transferred »

Embodiment

The invention is illustrated in an exemplary embodiment with reference to the drawing, in which an absorption heat pump system is shown schematically is shown, explained in more detail

The driving part of the heat pump consists of the expeller 1 and the absorber 2, wherein an L _TION 7 and the solution pump 8 and a pipe 5 and the throttle device 4, the solution circulation is maintained "via a valve combination 3, the expeller 1 and the absorber 2 Additionally connected by a bypass line 6.

The connection from the expeller 1 via the condenser 9 and the evaporator 10 to the absorber 2 takes place via lines 11 · The evaporator 10 is preceded by a throttle device 12 · Via two further valve combinations 13; 14 and a bypass line 15, the loser 9 and the evaporator 10 are bridged in the working medium circuit *

In normal heat pump operation, the working medium expelled in vapor form in the expeller 1 is releasing heat passed through the condenser 9 and condensed, expanded in the throttle device 12, for example from 20 5 kp / cm and absorbing heat of vaporization from the Environment passed through the evaporator 10 and finally fed to the absorber 2, where the cold steam under further Heat dissipation is absorbed by the poor solution

The poor solution is extracted from the expeller 1 via the line and under pressure reduction in the throttle device 4 »

for example transported from 20 to 5 kp / cm into the absorber. The enriched solution arrives via line 7 and the solution pump 8 under pressure increase in the expeller 1, where it is degassed again

In direct heating mode, the expelled steam experiences only a slight change in pressure of around 10 % of the output

output value, for example the pressure is reduced by 2 kp / cm.The steam is fed directly to the absorber via a bypass line 15 with a corresponding cross-section, while the degassed solution reached the absorber 2 with an equally small pressure reduction in the bypass line 6
Due to the prevailing in this way in the absorber

Pressure and temperature conditions are accordingly high flow temperatures achieved (approx. 90 C). The required Change in pressure in the bypass lines 6; 15 can auoh, by additional Droesel devices 16; 17 reached will.

If only the evaporator 10 is in the working medium circuit via a further valve combination (not shown) bridged, a partial condensation takes place in the condenser 9 the expelled steam with little heat emission than in absorber 2, for example for hot water preparation

The operation of the heat pump as a boiler heating can eventually also be performed so that the expelled working agent vapor is passed into the condenser 9 ₉ the temperature changers 18 and the evaporator 10 and stored there, and the direct heating mode described above with an essentially solvent-existing steam or · Hot Solution takes place, whereby a further improvement of the temperature conditions is achieved

List of the reference numbers used

1 H Expeller 2 16.17 absorber 3.13, 1 Valve combination 4.12, Throttle device 5.7.1 Connecting line 6.15 Bypass line 8th Solution pump 9 Condenser 10 Evaporator 18th Temperature changer

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Claims (5)

Claim Procedure for operating an absorption heat pump in direct heating mode to achieve higher flow temperatures, characterized in that the working medium vapor expelled in the expeller immediately and below slight pressure reduction and the degassed solution with an equally slight pressure reduction to the absorber are supplied for heat dissipation through absorption 2. The method according to claim 1, characterized in that the expelled working fluid vapor in the condenser and / or is stored in the temperature changer and in the evaporator and as a vaporous heat transfer medium in the essential vapor richer in solvent is used Method according to claim 1 and 2, characterized in that the expelled steam to reach different high heat dissipation is conducted via the condenser and the absorber 4 · Absorption heat pump for carrying out the method according to claims 1 to 3 »consisting essentially of an expeller, a condenser, an evaporator and an absorber, expansion devices in the working and solvent circuit and a solution pump, characterized in that the liquefier (9) and the Evaporator (10) or only the evaporator are bridged by a bypass line (15) and another Bypass line (6) is arranged in the solvent return. 5. Absorption heat pump according to claim 4 _f, characterized in that the bypass lines (6; 15) are provided with a cross section corresponding to the required pressure change or with throttle devices (16; 17) 6 · Absorption heat pump according to claim 4 and 5 »thereby characterized in that the throttle devices (4; 12) present in the system are designed to be adjustable and the Bypass lines (6j15) in direct heating mode via these Chokes are performed 7 · absorption heat pump according to claim 4 »characterized in that that a solution pump is used, the output of which can be reduced in direct heating mode.