JP2704550B2 - Automatic number control of hot water boilers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an automatic unit control method for controlling the number of hot water boilers to be operated optimally in accordance with a load value in a hot water boiler multi-can installation system. It is about.

[Conventional technology]

In recent years, with the increase in the health industry, facilities having a plurality of bathtubs and heated pools have been increasing. These facilities require heat sources for hot water supply to showers, washbasins, etc. and for heating indoors, in addition to bathtubs and heated water pools. When the temperature is raised, the heat source hot water is supplied to a separately provided heat exchanger.

As a heat source device for supplying the heat source hot water, a vacuum heater or a non-pressure canister heater capable of performing operation management without any qualification even with a large capacity is widely used. FIG. 7 shows a system diagram of a conventional embodiment, in which (1 ') is a vacuum heater, (5') is a heat exchanger,
(6 ') shows a circulation pump.

[Problems to be solved by the invention]

When the above system is used, there are the following problems. The circulation path of the heat source hot water has an independent configuration for each facility, and lacks heat isolation between the paths. That is, when designing the heat output, the peak value is calculated for each path and the total heat capacity of the heat source equipment is set. However, the peak of each path is unlikely to overlap, and the actual peak value is the calculated total heat capacity. Significantly lower than this, resulting in more inefficient operating conditions.

In addition, equipment costs are high because two heat exchangers, one for the heat source equipment and one for the load, are required for each system path. In addition, the vacuum heater and non-pressure boiler heater have an upper limit on the temperature of hot water supplied by the heat source. There is also a problem that only heat source hot water up to about 80 to 85 ° C. can be supplied.

[Means for solving the problem]

As means for solving the above problems, Japanese Patent Laid-Open No.
A control device for installing a multi-can of a hot water boiler as disclosed in -189247 has been invented and has obtained excellent effects in terms of high efficiency operation and stable supply of heat. This is a further improvement of the installation system.Specifically, in a hot water supply system in which a plurality of hot water boilers and loads are connected by a hot water supply path and a return path, the hot water temperature in a return side collecting part is detected, and this detection is performed. It is characterized by including an operation of detecting the circulating amount of hot water according to a temperature difference between the temperature and a preset temperature, and controlling the number of operating hot water boilers according to the detected value.

[Action]

According to the present invention, the number of operating hot water boilers installed in a plurality of units is controlled in accordance with the hot water temperature of the return collecting section or the circulation amount of the heat source hot water, so that the load state can be accurately grasped and the load state can be grasped. Therefore, an appropriate operating state of the boiler can always be obtained.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

In the figure, (1) is a plurality of hot water boilers installed in parallel, and these hot water boilers and loads (2) of hot water supply equipment, heating equipment, hot water pools, bathtubs, etc. are connected to a hot water supply system (3) and return. They are connected by the system (4). (5) is a heat exchanger,
(6) shows a circulation pump, (7) shows a temperature sensor, (8) shows a flow rate sensor, and (9) shows an automatic number controller.

The heat source hot water heated to a predetermined temperature by the hot water boiler (1) is circulated through a hot water supply system (3), a heat exchanger (5), and a return system (4) by the operation of a circulation pump (6). The system circulates through the system, and heat is exchanged by a heat exchanger (5) provided separately for the load (2), and heat is supplied to each load. In the present invention, a detector is provided to accurately grasp the state of the load, and the number of operating boilers is controlled so that a predetermined amount of heat can be supplied most efficiently according to the detected state of the load.

In the embodiment shown in FIG. 1, as compared to the temperature t ₀ which is provided on the return side collecting portion temperature sensor (7) detecting the water temperature t ₂ of this part, which had been previously set as the detected temperature Automatic load controller (9) that grasps the load status and responds to the temperature difference between the two.
Controls the number of operating hot water boilers (1). For example, water temperature t ₂ is decreased when increasing load is, the temperature difference increases, thereby increasing the supply total heat by increasing the operating number of hot water boilers (see Figure 2). By detecting the water temperature t ₂ of the return-side collecting portion, it is possible to perform good response volume control for variations in load.

When controlling the number of hot water boilers, the starting and stopping priorities are set in advance, and the hot water boilers are started and stopped according to the priorities. In addition, in order to average the operation rates of the respective hot water boilers, priority rotation is appropriately performed, and when an abnormal boiler occurs, the boiler having the next priority immediately operates and backs up. As the combustion control method of the hot water boiler, besides the ON-OFF control type, a three-position control type or a proportional control type can also be used. Also to control.

In addition, as a mounting position of the temperature sensor (7), a plurality of heat exchangers (5) are provided in parallel between the upper header and the lower header (not shown), and the temperature of the hot water on the return side is provided to the lower header. A temperature sensor for measurement may be attached. Then, it is possible to make the hot water temperature uniform and detect an accurate value.

In the embodiment shown in FIG. 3, the circulation amount Q of the heat source hot water is also detected by the flow rate sensor (8), and the number of hot water boilers (1) installed is controlled in accordance with the detected value. I have. When the circulation amount of the heat source hot water is varied according to the load state, for example, the operation of the heat source hot water circulation pump (6) is controlled by detecting the temperature of the load side circulating water by the temperature sensor (10). When the load decreases and the circulation amount of the heat source hot water decreases, this is detected by the flow rate sensor and the number of operating hot water boilers (1) is reduced. When the load increases, the circulation amount of the heat source hot water increases, so the number of operating hot water boilers is increased (see FIG. 4).

In order to detect the circulation amount of the heat source hot water, it may be directly detected using the flow rate sensor as described above, but in addition, a method of measuring the circulation flow velocity in the system, the pressure of the hot water supply side collecting part and There is a method of measuring the pressure difference from the pressure of the return-side collecting part.

When the circulation amount of the heat source hot water changes, if the circulation amount falls below a predetermined level, the temperature of the hot water in each of the hot water boilers rises, and a safety switch is activated to unnecessarily interlock the stop of the boiler. Therefore, it is necessary to secure the minimum circulation volume. As a method therefor, a method of adjusting the opening degree of the motor-operated valve (12) inserted into the tap hole of each hot water boiler based on the value of the circulation amount detected by the flow rate sensor (8) (see FIG. 5) The hot water supply line (3) and the return line (4) are connected by a bypass line (13), and the operation of a bypass pump (14) inserted in the bypass line is controlled.
There is a method of controlling based on the value of the circulation amount detected by the flow rate sensor (8) (FIG. 6). (11) indicates a controller.

As a hot water boiler used in the multi-can installation system according to the present invention, a once-through type is suitable. That is, since the once-through type hot water boiler can connect a plurality of boilers on the primary side, the plurality of boilers have a backup function for each other, and the heat exchanger only needs to be on the load side, so that equipment cost can be reduced. In addition, since the boiler primary can water can be used under pressure, high-temperature hot water (100 ° C. or higher) can be easily taken out.

〔The invention's effect〕

Since the present invention has the above-described configuration, each hot water boiler can be operated with high efficiency to increase the efficiency of the entire system, reduce running costs such as fuel costs, and reduce the load condition. It is possible to supply a predetermined amount of heat stably by accurately grasping. In addition, the stable supply of hot water with a constant temperature range to the load facilitates the design of the load-side heat exchanger, and detects the hot water temperature at the return-side gathering section and compares it with the set value to operate the boiler. By controlling the number of units or detecting the circulation amount of the heat source hot water and controlling the number of operating boilers according to the value, the responsiveness to load fluctuations and the accuracy of the response are further improved.

[Brief description of the drawings]

1 is a system diagram showing one embodiment of the present invention, FIG. 2 is a graph showing an example of control in the embodiment of FIG. 1, FIG. 3 is a system diagram showing another embodiment of the present invention, FIG. FIG. 4 is a graph showing an example of control in the embodiment of FIG. 3, and FIG.
FIG. 6 is a system diagram showing still another embodiment of the present invention, and FIG. 7 is a system diagram showing a conventional embodiment. (1) hot water boiler, (2) load (3) hot water supply line, (4) return line (5) heat exchanger, (6) circulating pump (7) …… Temperature sensor (8)… Flow sensor (9) …… Automatic unit controller

Claims (2)

(57) [Claims] 1. A plurality of hot water boilers (1) and a load (2)
The hot water system coupled the door in hot water pathways (3) and a return pathway (4), detects the hot water temperature t ₂ in the return-side collecting portion, the temperature t ₀ set in advance and the detected temperature depending on the temperature difference (t ₀ -t _2), automatic number control method for the hot water boiler, characterized by operating as controlling the operation number of the hot water boiler for each predetermined temperature range. 2. A plurality of hot water boilers (1) and a load (2).
In the hot water supply system connecting the hot water supply system (3) and the return system (4), the operation of varying the circulation amount of the hot water according to the value of the load and the circulation amount Q of the hot water are detected. Controlling the number of operating hot water boilers in accordance with the value.