JPH0745989B2 - Absorption heat pump capacity controller - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention provides a regenerator with a heat source fluid at a high temperature level [eg 100
Capacity control of the absorption heat pump that pumps up the heat of the heat source fluid at a low temperature level (for example, heat source water of 100 ° C. or less) while supplying the heating steam) and takes out the heat released by the absorber and the condenser. Regarding the device.

(B) Conventional technology As a conventional technology of the capacity control device for the absorption heat pump described above, one which adjusts the heating amount of the regenerator of the absorption heat pump by the temperature of the fluid to be heated at the outlet side of the condenser (for example, actual development Sho 61-3371). (See Japanese Patent Laid-Open No. 58-551551), as well as the one provided with means for correcting the adjustment amount based on the state quantity inside the heat pump.

(C) Problems to be Solved by the Invention In the above-mentioned conventional device, the former has an advantage that the heated fluid taken out from the absorption heat pump can be maintained at a substantially desired temperature, but when the flow rate of the heated fluid is reduced. , The heating amount of the regenerator is controlled so as to prevent the temperature at which it is taken out, so that the concentration of the solution concentrated in the regenerator, in other words, the solution sent to the absorber, drops, and the refrigerant absorption capacity of the absorber. As a result, the refrigerant vaporization ability of the evaporator is reduced, that is, the heat pumping ability of the evaporator is reduced.

In addition, the latter device has the advantage of correcting the excess or deficiency of the heating amount controller of the regenerator based on the state amount inside the absorption heat pump, but the point that the heating amount controller is used to keep the fluid to be heated at the desired temperature. Since it is the same as the former device, it has a drawback that when the flow rate of the fluid to be heated is reduced, the heat pumping ability of the evaporator is lowered as in the former device.

In view of the above problems, the present invention provides an apparatus capable of reducing the deterioration of the heat pumping capacity of an evaporator, maintaining a high operating efficiency of an absorption heat pump, and preventing overheating of a fluid to be heated. It is intended for.

(D) Means for Solving the Problems The present invention provides a capacity control device for an absorption heat pump for solving the above problems, in which a heating amount of a regenerator is a sensor of a refrigerant liquid amount in an evaporator or a condenser. The temperature of the fluid to be heated on the outlet side is adjusted by one of the signals of the temperature sensor, and when the temperature sensed by the temperature sensor is higher than the set temperature, it is adjusted by the signal of the temperature sensor. The configuration is adjusted by a signal.

(E) Action According to the control device of the present invention, when the fluid to be heated reaches a temperature [set temperature] close to the overheat region, the heating of the regenerator is limited by the signal of the temperature sensor to input heat to the absorption heat pump. It is possible to exert the effect of reducing. For this reason,
Overheating of the fluid to be heated can be prevented.

And also, when the superheated fluid is in a temperature region far from the superheat region, the function of adjusting the refrigerant liquid storage amount in the evaporator while adjusting the heating amount of the regenerator by the signal of the refrigerant liquid amount sensor,
In other words, the effect of adjusting the concentration of the solution circulating in the absorption heat pump to a desired value can be exhibited.
Therefore, even when the flow rate of the fluid to be heated to the absorption heat pump is reduced, the decrease in the refrigerant absorption capacity of the absorber is mitigated to reduce the decrease in the refrigerant vaporization capacity of the evaporator, that is, the heat pumping capacity of the evaporator. Therefore, it is possible to maintain high operation efficiency of the heat pump.

(F) Embodiments The drawings are schematic configuration diagrams showing an embodiment of the capacity control device for an absorption heat pump according to the present invention.

In the figure, (1) is a regenerator, (2) is a condenser, and (3)
Is an evaporative absorber forming an evaporator (4) and an absorber (5). Then, these devices are connected by a solution flow path and a refrigerant flow path (not shown) to form a refrigerant and solution circulation path similar to the conventional absorption heat pump.

(6) is a heater of the regenerator (1), (7) is an evaporator (4)
And (8) and (9) are the coolers of the absorber (5) and the condenser (2), respectively. Further, (10) is a refrigerant liquid reservoir of the evaporator (4).

Reference numeral (11) is a pipe connected to the heater (6), and superheated steam flows through this pipe. (12) is a water source and cooler (8) not shown
A water pipe connected to the inlet side, (13) a water pipe connected to the cooler (8) outlet side and the cooler (9) inlet side, and (14) a cooler (9) outlet side and a load side not shown, for example, a hot water tank It is a water pipe connected to a boiler or the like. Further, (15) and (16) are pipes connected to the heat supply device (7), through which heat source water such as hot waste water flows. In addition, (17) is a turbine for generator,
The branch pipe (18) of the pipe (11) is connected to this.

Further, (S _L ) is a liquid level sensor provided in the refrigerant liquid reservoir (10) of the evaporator (4), (V) is a flow control valve provided in the pipe (11), and (C _L ) is a liquid level. It is a controller that inputs the signal of the sensor (S _L ) and outputs the control signal to the flow control valve (V). Further, (C _T ) receives a signal from a temperature sensor (S _T ) provided in the water pipe (14) to input the flow control valve (V).
Is a temperature controller that outputs a control signal to the temperature controller (C _SET ) and a temperature comparator (C C) that determines whether the set temperature and the temperature sensed by the temperature sensor ( _ST ) are high or low. _J ) is provided. Also, (R _C ) is a relay type changeover switch, and the relay contact piece of this switch has a temperature comparison unit (C _J ) when the sensed temperature of the temperature sensor (S _T ) is higher than the set temperature. While being connected to the H side by the discrimination signal, it is connected to the C side by the discrimination signal when the sensed temperature is equal to or lower than the set temperature. That is, the flow control valve (V) is controlled by either the controller ( _CL ) or the temperature controller ( _CT ) control signal based on the upper limit temperature of the water in the pipe (14), in other words, the liquid level. It is controlled by the signal of either the sensor (S _L ) or the temperature sensor (S _T ).

The liquid level detecting means is not limited to the liquid level sensor and may be, for example, a float switch, and the temperature detecting means is not limited to the temperature sensor and may be, for example, a thermoswitch.

Next, an operation example of the absorption heat pump capacity control device (hereinafter referred to as the present device) configured as described above will be described together with the operation of the heat pump.

During operation of the absorption heat pump, when the water in the water pipe (14) is at or below the upper limit temperature (for example, 100 ° _C. ), the contact piece of the changeover switch (R _C ) is connected to the C side. Then, the flow control valve (V) is controlled by the signal of the liquid level sensor (S _L ) via the controller (C _L ).

In the above case, when the fluid to be superheated flows through the absorption heat pump under rated conditions, by the way, the flow rate of water as the fluid to be heated to the absorption heat pump is 100 m ³ / h, the water temperature on the inlet side of the absorption heat pump is 30 ° C., When the heat pump is operated under the condition that the water temperature at the outlet side is 70 ° C [warm water output 4000Mcal / h], the liquid level of the refrigerant sump (10) of the evaporator (4) is at a rated level [eg, sump (10 ) Near the upper limit level)
The flow rate control valve (V) is maintained at the rated opening. Now, for example, when the flow rate of water is reduced to 50 m ³ / h, the refrigerant absorption capacity of the absorber (5) decreases, and with this, the refrigerant vaporization capacity of the evaporator (4) In other words, the evaporator (4) As a result, the ability to pump heat from the heat source water decreases, and the operating efficiency of the absorption heat pump deteriorates. At this time, since the liquid level of the refrigerant liquid reservoir (10) of the evaporator (4) also rises, if this is left as it is, the refrigerant liquid overflows from the refrigerant liquid reservoir (10) and the inside of the absorber (5) It will be mixed in the solution, and the operation efficiency of the absorption heat pump will be further deteriorated.

In such a case, in this device, the liquid level sensor (S _L ) detects the rise of the liquid level and sends it to the controller (C _L ) as a signal, and the controller (C _L ) receiving this signal The opening amount of the flow control valve (V) is controlled to be decreased so that the position of the regenerator (1) is returned to the rated level. As a result, the amount of the refrigerant separated from the solution in the regenerator (1) decreases, and the amount of the refrigerant liquid flowing into the evaporator (4) via the condenser (2) decreases, and the refrigerant sump (10)
The overflow of the refrigerant liquid from the inside is prevented. That is, it is possible to prevent the operation efficiency of the absorption heat pump from being lowered due to the overflow. The reduced amount of the heat source steam supplied to the regenerator (1) will be supplied to the generator turbine (17). By the way, the flow rate of water as the fluid to be heated is 50
reduced to m ³ / h, and when the water temperature on the inlet side of the absorption heat pump is changed to 10 ° C., the liquid level of the reservoir the refrigerant fluid (10) by the capacity control of the apparatus is maintained at the rated level, the absorption heat pump outlet The water temperature on the side is 90 ° C, and a hot water output of 4000Mcal / h can be obtained.

On the other hand, when the flow rate of water as the fluid to be heated is increased to 200 m ³ / h, the liquid level in the refrigerant sump (10) drops, contrary to the decrease in the flow rate of water. signal by the controller (C _L) of (S _L) increases controlling the opening of the flow control valve (V). As a result, the concentration of the solution in the regenerator (1) is increased, in other words, the amount of refrigerant separated from the solution is increased, and the amount of refrigerant liquid flowing into the evaporator (4) via the condenser (2) is increased. It increases and the liquid level in the refrigerant liquid reservoir (10) begins to rise again. Then, the concentration of the solution circulating through the heat pump is returned to the same as before the flow rate of the heated fluid [water] was increased,
Moreover, since the water flow rate in the cooler (8) of the absorber (5) increases and the refrigerant absorbing power of the solution is strengthened, the refrigerant vaporizing capacity of the evaporator (4) improves more than before the increase of the water flow rate. Therefore, the heat pumping capacity of the evaporator of the heat pump is improved, the operating efficiency of the heat pump is increased, and the hot water output is also increased.

In this way, this device maintains the refrigerant liquid storage amount in the evaporator (4) at the rated value [almost the entire capacity of the refrigerant liquid reservoir (10)] while adjusting the heating amount of the regenerator (1). For example, it exerts the function of keeping the concentration of the solution at the highest concentration possible in the absorption heat pump. Then, according to this device, when the flow rate of water (fluid to be heated) to the heat pump is reduced or when the inflow temperature of water to the heat pump is increased, the solution is maintained at the same concentration as before the change. It is possible to prevent the overflow of the refrigerant liquid to the refrigerant and prevent the generation of a large heat loss, but when the flow rate of the water is increased or the inflow temperature is lowered, it is possible to exert a larger refrigerant absorption force than before the change. You can Therefore, the heat pumping ability of the evaporator (4) of the heat pump, that is, the operation efficiency of the heat pump can be maintained at a high level.

It is needless to say that the above-mentioned rated level can be set to any level other than the upper limit level of the refrigerant liquid reservoir (10).
This setting is made by arbitrarily setting the volume (resistance value) of the level setter (not shown) of the controller ( _CL ).

Also, in this device, when the temperature of the water (fluid to be heated) flowing out from the heat pump exceeds 100 ° C, the changeover switch (R) is turned on by the discrimination signal of the temperature comparison unit (C _J ) of the temperature controller (C _T ). relay contact piece of _C) is switched to the H side, the flow control valve (V) is throttled by a signal of the temperature sensor (S _T). As a result, the heat input of the absorption heat pump is reduced, and the amount of heat released from the condenser (2) is also reduced, so that the water (fluid to be heated) heated by this condenser is cooled to below 100 ° C, and its overheating is prevented. To be done. As described above, according to the present device, the water in the cooler (9) of the condenser (2) is suppressed to 100 ° C. or lower, and the saturated vapor pressure thereof is maintained at the atmospheric pressure or lower. Therefore, the cooler (9) Since it does not have to be a pressure resistant structure, cost reduction and weight reduction can be achieved.

(G) Effects of the Invention As described above, the present invention provides the absorption heat pump with the effect of reducing heat loss that accompanies changes in the conditions such as the temperature and flow rate of the heated fluid of the heat pump, and improves the heat pumping ability. It has a high practical value as an effect of reducing the decrease or an effect of improving the heat pumping ability, maintaining the operation efficiency of the heat pump at a high level, and preventing overheating of the fluid to be heated.

[Brief description of drawings]

The drawings are schematic structural explanatory views showing an embodiment of a capacity control device for an absorption heat pump according to the present invention. (1) …… Regenerator, (2) …… Condenser, (4) …… Evaporator, (5) …… Absorber, (9) …… Cooler, (10) ……
Refrigerant sump, (C _L ) …… Controller, (C _T ) …… Temperature controller, (C _SET ) …… Temperature setting section, (C _J ) …… Temperature comparison section, (S _T ) …… Temperature sensor , (S _L ) ... Liquid level sensor, (R _C ) ... Changeover switch, (V) ... Flow control valve.

Claims (1)

[Claims] 1. A control valve for adjusting a heating amount of a regenerator, a controller for outputting a control signal to the control valve according to an input signal from a liquid amount detecting means such as a refrigerant liquid amount sensor of an evaporator, and a condenser outlet side. A temperature controller for outputting a control signal to the control valve in response to a signal from a temperature detecting means such as a temperature sensor for the fluid to be heated, and a temperature setting unit and a temperature set by the temperature controller. A capacity control device for an absorption heat pump, comprising a temperature comparison unit for determining whether the temperature is higher or lower than the temperature sensed by the temperature sensor, and a switch for switching a control signal to the control valve according to a determination signal of the temperature comparison unit.