JP2839179B2 - Absorption chiller / heater and control method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption chiller / heater provided with a high-quality fuel system and a waste heat utilization system, and having a heat exchanger in which waste heat is supplied to the piping of the waste heat utilization system from outside. Alternatively, the present invention relates to an absorption refrigerator (hereinafter, referred to as an absorption chiller / heater including the absorption refrigerator) and a control method thereof.

[0002]

2. Description of the Related Art As an absorption chiller / heater or an absorption chiller provided with a high-quality fuel system and a waste heat utilization system, and provided with a heat exchanger in which waste heat is supplied from the outside to piping of the waste heat utilization system. For example, there is one disclosed in Japanese Patent Application No. 6-73428 filed earlier by the present applicant.

[0003]

Here, in an absorption chiller / heater, the solution pump may stop in response to various signals generated during operation (such as a detection signal of a chilled water temperature lower than a predetermined value). is there.

[0004] However, if a heat exchanger into which waste heat is supplied from the outside is interposed in the pipe of the waste heat utilization system, even if the solution pump is stopped, the waste heat from the outside through the heat exchanger. There are cases where it is thrown. In such a case, since the solution is not circulated, the solution inside the heat exchanger is concentrated and may be crystallized in the heat exchanger. When crystallization occurs, the system in which the heat exchanger is interposed becomes unusable. Therefore, it is desired to avoid the occurrence of crystallization, but no effective measures have been proposed in the prior art.

The present invention has been proposed in view of the above-mentioned problems of the prior art, and is an absorption chiller / heater provided with a high-quality fuel system and a waste heat utilization system. It is an object of the present invention to provide an absorption chiller / heater that can effectively prevent crystallization from occurring in a heat exchanger that is interposed and receives exhaust heat from the outside, and a control method thereof.

[0006]

SUMMARY OF THE INVENTION An absorption chiller / heater of the present invention includes a high-quality fuel system and a waste heat utilization system, and includes a heat exchanger in which waste heat is supplied from outside to piping of the waste heat utilization system. In the control method of the interposed absorption chiller / heater, a step of detecting that a solution pump operation stop signal has been generated, and a step of determining whether a predetermined time has elapsed since the solution pump operation was stopped,
After the lapse of the predetermined time, causing the fluid containing waste heat to flow through the heat exchanger.

Here, in the control method of the absorption chiller / heater of the present invention, the step of detecting the temperature of the fluid containing the exhaust heat and the flow of the fluid corresponding to the temperature are supplied to the heat exchanger side. Determining the bypass amount of the fluid as described above.

Further, the absorption chiller / heater of the present invention comprises a high-quality fuel system and a waste heat utilization system, and an absorption heat exchanger in which waste heat is supplied from outside to piping of the waste heat utilization system. In a chiller / heater, a branching means is interposed in a piping system for a fluid containing waste heat, and a solution pump operation stop detecting means for detecting that a solution pump operation stop signal is generated, and an operation of the solution pump A timer means for determining whether a predetermined time has elapsed from the stop, and an output signal from the solution pump operation stop detecting means and the timer means is transmitted so that a fluid containing waste heat bypasses the heat exchanger. And control means for outputting a control signal to the branch means.

Here, in the absorption chiller / heater of the present invention,
Temperature detecting means for detecting the temperature of the fluid containing waste heat and outputting the detection result to the control means, wherein the control means supplies the detected heat to the heat exchanger in response to the detected temperature of the fluid. Preferably, a control output is transmitted to the branching means so as to adjust the flow rate of the fluid.

In practicing the present invention, the solution pump operation stop signal includes a start / stop signal, a signal for detecting that the cold water temperature is lower than a predetermined temperature during cooling, and a signal for detecting that the hot water temperature is higher than the predetermined temperature during heating. There are signals to be detected.

Further, in the present invention, when a stop signal is generated due to an abnormal operation, the control means allows the fluid to bypass the heat exchanger and stops the operation of the absorption chiller / heater. preferable. Here, as a stop signal due to an operation abnormality, a regeneration system abnormality signal (regeneration pressure is higher than a reference value, exhaust gas temperature is higher than a reference value, regeneration temperature is higher than a reference value, regenerator liquid level is a reference level ), Combustion system abnormal signal (such as abnormal gas pressure), motor system abnormal signal (solution pump overcurrent, refrigerant blower overcurrent, burner blower overcurrent, etc.), equipment system abnormal signal (cold temperature) Water pump interlock is OFF, cooling water pump interlock is OFF, etc.).

Here, the term "fluid containing waste heat" is a term used to mean not only hot waste water but also exhaust gas, waste steam and the like.

In this specification, the term "absorption chiller / heater" is used to include an absorption refrigerator.

[0014]

According to the present invention having the above-described structure,
If the solution pump operation stop detecting means detects that the solution pump operation stop signal has been generated, the timer means determines whether or not a predetermined time has elapsed from the stop of the solution pump operation, and the predetermined time has elapsed. Then, a control signal is outputted from the control means to the branch means, so that the fluid containing waste heat bypasses the heat exchanger. If the fluid containing waste heat is bypassed, heat is not supplied to the heat exchanger from the outside, so even if the solution pump is stopped and the absorbing solution remains inside the heat exchanger, the residual Concentration or crystallization of the resulting solution is avoided.

In the present invention, the temperature of the fluid containing waste heat is detected by a temperature detecting means, and if the temperature is higher than a predetermined value, the fluid is supplied to the heat exchanger side, and the temperature is set to a predetermined value. If the fluid is lower than the value, the fluid is allowed to bypass the heat exchanger, so that the fluid having a low temperature is not supplied to the heat exchanger, and the fluid is circulated in the exhaust heat utilization system of the absorption chiller / heater. This prevents a situation in which heat is deprived when the absorbing solution passes through the heat exchanger. That is, efficient use of exhaust heat is guaranteed.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment of the present invention.
What is indicated by the reference numeral 20 (20A to 20K) is an absorption chiller / heater. The absorption chiller / heater 20 (20A to 20A)
K) will be described later.

In order to supply exhaust heat from the exhaust heat line 2 to the absorption chiller / heater 20 (20A to 20K), an exhaust heat input line L2 is provided, and the line L2 holds fluid. A heat exchanger 32 (32A to 32A) for supplying heat to the absorption solution flowing through the waste heat utilization system of the absorption chiller / heater.
K) is interposed.

In the embodiment shown in FIG. 1, a three-way valve V1 is provided at the junction of the exhaust heat line 2 and the exhaust heat input line L2 as a branching means so that the flow rate can be adjusted.
1 is transmitted with a valve opening control signal from the control means 50 via a signal transmission line SL1. And the control means 50
A stop signal of a solution pump (not shown in FIG. 1) in the absorption chiller / heater 20 (20A to 20K), an absorption chiller / heater operation switch OFF signal, an operation abnormality detection signal, and the like are sent to the sensor 52, respectively. Signal transmission line SL from 54, 56
2, SL3 and SL4.

In FIG. 1, reference numeral 21 denotes a high quality fuel system fuel line.

Next, the operation of the illustrated embodiment will be described with reference to FIGS.

The operation switch of the absorption chiller / heater 20 (20A to 20K) is turned on or the reset switch is turned on.
When N is reached (step S1 in FIG. 2), the operation of the absorption chiller / heater in FIG. 1 is started. The three-way valve V1 receives the hot waste water from the exhaust heat line L2 and absorbs the hot water from the hot / cold water heater 20 (20A-20A).
The opening is set so as to be supplied to the K) side (step S2).

When the absorption chiller / heater 20 (20A to 20K) is operated, whether any of the sensors 52, 54 and 56 has stopped the solution pump during the operation of the absorption chiller / heater 20 (20A to 20K) Is always determined (step S
3). If such a signal does not occur, the state of step S2 continues (step S3 is a NO loop).

On the other hand, if a solution pump stop signal is generated (YES in step S3), it is determined whether such a signal continues for a predetermined time or more (step S4). Here, the phrase “predetermined time” refers to the heat exchanger 32 (32A to 3A).
2K) means the time during which the solution remaining in the solution does not condense above a certain concentration, but such time and "constant concentration" vary depending on the installation conditions of the absorption chiller / heater, various specifications, etc. It is. That is, the “predetermined time” is a constant determined on a case-by-case basis.

If the solution pump stop signal is released before the elapse of a predetermined time, the heat exchanger 32 (32A to 32K)
The solution remaining in the inside does not condense, and the operation of the absorption chiller / heater continues as it is (NO in step S4). On the other hand, if the solution pump stop signal is not canceled even after the lapse of the predetermined time (step S4: YES loop), the solution remaining in the heat exchanger 32 (32A to 32K) may be condensed. Therefore, necessary measures are taken to interrupt the input of the exhaust heat. Specifically, the three-way valve V1 is switched to the bypass side (Step S5), and the fluid (for example, hot waste water) flowing in the exhaust heat line 2 is discharged to the heat exchanger 32.
(32A to 32K) is prevented.

Then, it is determined whether or not the operation of the solution pump has been resumed (step S6). If the solution pump stop signal remains generated (step S6 is NO), the hot water flowing through the exhaust heat line 2 is discharged. Is the heat exchanger 32 (32A-3)
2K) is not supplied (the state of step S5). On the other hand, when the solution pump stop signal disappears and the operation of the solution pump is restarted (step S6 returns to Y
ES), the three-way valve V1 is switched again to supply the hot waste water from the exhaust heat line L2 to the absorption chiller / heater 20 (20A to 20K) (step S2).

When the operation is stopped, the control as shown in FIG. 3 is performed in addition to the control routine during the normal operation shown in FIG. The operation switch of the absorption chiller / heater 20 (20A to 20K) is turned off by one of the sensors 52, 54, and 56.
When it is detected that the state has been entered (operation stop signal transmission) or that an abnormal situation has occurred during operation (operation abnormality signal transmission) (step S11 or S12 in FIG. 3),
The three-way valve V1 is switched to the bypass side (step S
13). Thereby, the fluid (for example, hot waste water) flowing in the exhaust heat line 2 is not supplied to the heat exchanger 32 (32A to 32K), and the problem of the condensation or crystallization of the solution inside the heat exchanger does not occur.

Thereafter, the chiller / heater 20 (20A to 20K)
Is performed (step S14), and the operation is stopped (step S15).

FIGS. 4 and 5 show a second embodiment of the present invention. 4, the exhaust heat line L2, heated effluent temperature T temperature detecting means (temperature sensor) _{60 H} to detect a is provided, and its output is input to the control unit 50 via a signal transmission line SL5. Other configurations are the same as those in FIG.

The operation of the second embodiment will be described with reference to FIG. 5. When the operation switch of the absorption chiller / heater 20 (20A to 20K) is turned on or the reset switch is turned on (step S1). Thereafter, the temperature drainage temperature _TH is detected by the temperature sensor 60 (step S22), and it is determined whether the temperature is higher or lower than a predetermined value (determined on a case-by-case basis by the specifications and installation conditions of the device) ( Step S23). The heated effluent temperature T _H is higher than the set value absorption chiller heater side to the available heat (corresponding to thermal effluents temperature T _H flow) is supplied (step S24), and than the set value If lower, the absorption chiller / heater is bypassed (step S25). The control routine of step S3 and subsequent steps is the same as that described with reference to FIG.

FIGS. 6-17 show the absorption chiller / heater (absorption refrigerator) 20, 20A-20K, respectively. The absorption refrigerator 20, 20A to 20K includes an evaporator 9, an absorber 1
0, a high-temperature regenerator 11, a low-temperature regenerator 12, a condenser 13, a high-temperature solution heat exchanger 14, a low-temperature solution heat exchanger 15, a refrigerant pump P9, a solution pump P10, and various lines connecting these members. The cooling water is supplied to a cooling load (not shown) through the cooling water line 6. And the absorber 10,
Cooling water line CL for supplying cooling water to condenser 13
And circulates cooling water cooled by a cooling tower (not shown). Reference numeral 21 denotes a fuel line for supplying high-quality fuel to the high-temperature regenerator 11 heating means using high-quality fuel.

Here, a pipe line L1 between the high-temperature solution heat exchanger 14 and the low-temperature solution heat exchanger 15 is connected to a dilute solution line (hereinafter, referred to as an absorbent) including the high-temperature solution heat exchanger and the low-temperature solution heat exchanger. , "Dilute solution line"). The dilute solution line L1 has heat source heat exchangers 32, 32A to 32K for exchanging heat between the warm drainage flowing through the branch line L2 and the absorbent dilute solution flowing through the dilute solution line.
Is interposed. In other words, the heat source heat exchanger 32
As a result, the amount of heat of the warm wastewater or steam at 40 ° C to 120 ° C is transferred to the absorbent dilute solution in the dilute solution line L1.

[0033]

According to the present invention described above, even if the solution pump is stopped and the absorbing solution remains inside the heat exchanger,
Since the remaining solution is prevented from condensing or crystallizing, various inconveniences associated with crystallization are completely prevented.

In the present invention, if the temperature of the fluid containing exhaust heat is detected by the temperature detecting means, efficient use of exhaust heat is guaranteed.

Further, it is possible to cope not only with the stop of the solution pump during the operation of the chiller / heater but also with the operation stoppage of the chiller / heater itself.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a view showing a control flowchart of the embodiment of FIG. 1;

FIG. 3 is a control flowchart of the embodiment of FIG. 1;
The figure which shows the control different from FIG.

FIG. 4 is a block diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram showing a control flowchart of the embodiment of FIG. 4;

FIG. 6 is a block diagram showing an absorption chiller / heater or an absorption refrigerator used in the present invention.

FIG. 7 is a block diagram showing an absorption chiller / heater or an absorption refrigerator different from that shown in FIG. 6;

FIG. 8 is a block diagram showing an absorption chiller / heater or an absorption refrigerator different from those shown in FIGS.

FIG. 9 is a block diagram of an absorption chiller / heater or absorption chiller different from that shown in FIGS. 6-8.

FIG. 10 is a block diagram of an absorption chiller / heater or absorption chiller different from that shown in FIGS. 6-9.

FIG. 11 is a block diagram of an absorption chiller / heater or absorption chiller different from that shown in FIGS. 6-10.

FIG. 12 is a block diagram of an absorption chiller / heater or absorption chiller different from that shown in FIGS. 6-11.

FIG. 13 is a block diagram of an absorption chiller / heater or absorption chiller different from that shown in FIGS. 6-12.

FIG. 14 is a block diagram of an absorption chiller / heater or absorption chiller different from that shown in FIGS. 6-13.

FIG. 15 is a block diagram of an absorption chiller / heater or absorption chiller different from that shown in FIGS. 6-14.

FIG. 16 is a block diagram of an absorption chiller / heater or absorption chiller different from that shown in FIGS. 6-15.

FIG. 17 is a block diagram of an absorption chiller / heater or an absorption refrigerator different from that shown in FIGS. 6-16.

[Explanation of symbols]

2 ・ ・ ・ Exhaust heat line 6 ・ ・ ・ Cold water line 9 ・ ・ ・ Evaporator 10 ・ ・ ・ Absorber 11 ・ ・ ・ High temperature regenerator 12 ・ ・ ・ Low temperature regenerator 13 ・ ・ ・ Condenser 14 ・ ・ ・ High temperature Solution heat exchanger 15 ・ ・ ・ Low temperature solution heat exchanger P9 ・ ・ ・ Coolant pump P10 ・ ・ ・ Solution pump L1, L1A, L1B, L1C, L1D, L1E, L1
F, L1G, L1J, L1K: diluted solution line L2: exhaust heat input line 20, 20A, 20B, 20C, 20D, 20E, 20
F, 20G, 20H, 20I, 20J, 20K: absorption chiller / heater or absorption refrigerator V1: three-way valve 60: temperature sensor CL: cooling water line 21: fuel line 32, 32A , 32B, 32C, 32D, 32E, 32
F, 32G, 32H, 32I, 32J, 32K ... heat source heat exchanger SL1 ... signal transmission line 50 ... control means 52, 54, 56 ... sensors SL2, SL3, SL4, SL5 ..Signal transmission lines

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F25B 15/00 306 F25B 15/00 303

Claims (4)

(57) [Claims] 1. A method for controlling an absorption chiller / heater comprising a high-quality fuel system and a waste heat utilization system, wherein a heat exchanger for introducing waste heat from the outside into piping of the waste heat utilization system is provided. A step of detecting that a pump stop signal has been generated, and a step of determining whether or not a predetermined time has elapsed since the stop of the operation of the solution pump, and removing the fluid containing waste heat after the lapse of the predetermined time. A step of bypassing the heat exchanger. Detecting a temperature of the fluid containing waste heat; and determining a bypass amount of the fluid such that a fluid having a flow rate corresponding to the temperature is supplied to the heat exchanger side.
The method for controlling an absorption chiller / heater according to claim 1, comprising: 3. An absorption chiller / heater provided with a high-quality fuel system and a waste heat utilization system, and provided with a heat exchanger in which waste heat is supplied from outside to piping of the waste heat utilization system, wherein the waste heat is contained. A branch means is interposed in the piping system of the fluid to be discharged, a solution pump operation stop detecting means for detecting that a solution pump operation stop signal has been generated, and whether a predetermined time has elapsed since the solution pump operation was stopped. A control signal to the branching means such that a fluid containing waste heat bypasses the heat exchanger when an output signal from the solution pump operation stop detection means and the timing means is transmitted. And a control means for outputting a signal. 4. A temperature detecting means for detecting a temperature of a fluid containing waste heat and outputting a detection result to the control means, wherein the control means responds to the detected temperature of the fluid by detecting the temperature of the fluid. 4. The absorption chiller / heater according to claim 3, wherein a control output is transmitted to said branch means so as to adjust a flow rate of said fluid supplied to the exchanger side.