JPH07225054A - Number control method of hot water suppliers or cold water suppliers - Google Patents

Abstract

PURPOSE:To ensure long life of instruments and improve efficiency by increasing the extent of the amount of required heat corresponding to one hot water supplier or one cold water supplier, and reducing the number of times of starting and interruption of the instruments by calculating (n) hot water suppliers or cold water suppliers driver based on a specific equation after evaluation of the amount of the required heat. CONSTITUTION:A hot water or cold water system is constructed such that N (>=2) hot water suppliers or cold water suppliers B1 to BN each with an output of a stepwise control type and a load Y are connected with each other by a hot water or cold water supply passage K1 having a circulation pump P and a return passage K2. In a first step the amount of required heat Q is estimated. In a second step (n) hot water suppliers or cold water suppliers B1 to BN (herein, boilers are started in the order of small n, and n is an integer satisfying N>=n>=1) driven by the following equation are estimated with a number controller C. Namely, there is used an inequality: m1 q1+...mn-1qn-1<Q<=m1q1+...-mnqn. Herein, qn is a heat output from hot water supplier or cold water supplier B1 to BN, and mn is a factor which satisfies 1<=mn and m1 q1+...mn-1qN-1<q1+...qN.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water or cold water system in which multiple cans of a hot water machine or a cold water machine are installed, so as to optimally control the number of operating hot water machines or cold water machines in accordance with a load, that is, a required heat quantity. The present invention relates to the automatic number control method.

[0002]

2. Description of the Related Art Conventionally, for example, in a hot water supply system (hot water system) in which a plurality of hot water boilers (hot water generators) and loads are connected by a hot water supply path and a return path, a required heat quantity (insufficient heat quantity) and a heat output per machine. A technique for obtaining the shortage number from the above and increasing or decreasing the number of operating units is known from Japanese Patent Laid-Open No. 2-219946 and Japanese Utility Model Laid-Open No. 1-134839.

[0003]

In the conventional system as described above, when the heat output per hot water boiler is q and the required heat quantity is Q, (n-1) * q <Q
The number of operating units, that is, the number n of combustion-permitted (instructed) units is calculated by the formula ≦ n × q. However, with this calculation method, the heat output becomes 0 to q minutes larger than the required heat amount of the entire system.
For example, even if the required amount of heat is 1.1q, the heat output is 2q for two hot water boilers, so the hot water boiler is turned ON-
There is a problem in that the power is frequently turned off and the operating efficiency is reduced.

[0004]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems, and the invention of claim 1 is such that N (≧ 2) units of hot water whose output is stepwise controlled. In a hot water or cold water system in which a hot water or cold water supply system path and a return path are connected between a hot water or cold water machine B ₁ ... B _N and a load, a step of calculating a necessary heat quantity Q and n units driven by Hot or cold water machine B ₁ ... B _n (however,
The hot water machine or the cold water machine shall be started in ascending order of n,
N ≧ n ≧ 1), and a formula: m ₁ q ₁ + ... + m _n-1 q _n-1 <Q ≦ m ₁ q ₁
+ ... + m _n q _n However, q _n is the heat output of the hot water machine or the cold water machine B _n . m _n is 1 ≦ m _n , and m ₁ q ₁ + ... + m _N-1 q _N-1 <
A coefficient that satisfies q ₁ + ... + q _N. The invention of claim 2 is
In claim 1, all m _n are equal, the invention of claim 3 is characterized in that all q _n are equal in claim 1 or 2, and the invention of claim 4 is In 1, 2 or 3, the method includes a step of obtaining the required heat quantity Q by the following equation. Q = (T0-tm) × W where T0 is the target temperature, tm is the return water temperature, and W is the flow rate.

[0005]

According to the means described in claims 1 and 2 above,
Since the required heat quantity range for each hot water boiler is multiplied by m _{n as} compared with the conventional one, the number of times of starting and stopping the hot water boiler is reduced. Further, according to the means described in claim 3, since the return water temperature is detected, the number of hot water machines or cold water machines can be controlled with good responsiveness to the increase and decrease of the load.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, B ₁ ... B _N are N (≧ 2) non-hot water type hot water generators (hot water boilers) whose outputs are ON-OFF type, which are installed in parallel with each other and are connected to the hot water supply side of each water heater and return. The hot water (water) side is connected to a hot water supply side collecting portion (header) and a return hot water side collecting portion (header) which are not shown. These water heaters are connected to a hot water supply facility, a heating facility, a hot water pool, a load Y such as a bathtub (heat exchanger in this embodiment) through a hot water supply route (supply route) K1 and a return route K2. P is a circulation pump, TC is a temperature sensor provided in a portion of the return route K2 near the water heater so as to detect the temperature tm of the return hot water, and F is provided at an appropriate position of the hot water supply route K1 (or the return route K2). It is a flow rate sensor that detects W. still,
In the present embodiment, a multi-tube once-through boiler having a large number of substantially vertical water pipes is used as the hot water boiler, and the hot water produced by the water pipe is directly supplied to the load side, but the type of boiler is not limited to this. Further, the hot water may be directly supplied to the load side via an indirect heat exchanger (not shown) instead of directly supplying the hot water to the load side.

C is a control target temperature T0 related to the return hot water temperature.
The return water temperature tm, the method of the present invention from the flow W automatic number controller for controlling the ON-OFF number of water heater B ₁ ··· B _N, for n number instructing combustion by the following equation (ON) The water heaters B ₁ ... B _n (provided that the boilers are started in ascending order of n, and N is an integer of n ≧ 1) are calculated.

Formula 1: m ₁ q ₁ + ... + m _n-1 q _n-1 <
Q ≦ m ₁ q ₁ + ... + m _n q _n

Equation 2: Q = (T0-tm) × W

However, q _n is the heat output of the water heater B _n , m _n is 1 ≦ m _n , and the equation 3: m ₁ q ₁ + ... + m _N-1 q _N-1 <
A coefficient that satisfies q ₁ + ... + q _N. The expression 3 means that m ₁ q ₁ + ... + m _N-1 q _N-1 is equal to or less than the total heat output q ₁ + ... + q _N corresponding to the maximum required heat quantity. .

Now, _assuming that m _n are all equal and m _n = m ₀ , the formula 1 and the formula for the coefficient m _n are as follows.

Equation 11: m × (q ₁ + ... + q _n-1 ) <
Q ≦ m × (q ₁ + ... + q _n )

Formula 31: 1 <m <(q ₁ + ... + q _N )
/ (Q ₁ + ... + q _N-1 )

Further, q _n are all made equal, and q _n = q ₀
Then, the equations 11 and 31 are as follows.

Equation 12: m × (n−1) × q ₀ <Q ≦ m ×
n × q ₀

Expression 32: 1 <m <N / (N-1)

More specifically, for example, n = 5, all q _n are equal, the heat output of the water heater q ₀ = 1400 kcal / min, the control target temperature T0 = 85 ° C., and the flow rate W = 350 l / min. In this case, the combustion instruction number is determined in relation to the number change reference heat quantity (reference required heat quantity for changing the combustion instruction number) or the corresponding number change reference temperature (reference temperature for changing the combustion instruction number). The required heat quantity may be restated as the required heat quantity.

The reference heat quantity for changing the number of vehicles is determined by the above equation 12. That is, from 1 <m ₀ <5/4, for example, m ₀ = 1.2
Then, the required heat quantity for one water heater is 0 <Q ≦ 1400
× 1.2, the required heat for two water heaters is 1400 × 1.2 <Q
≦ 2800 × 1.2, the required amount of heat for 3 water heaters is 2800 × 1.2
<Q ≦ 4200 × 1.2, the required heat for 4 water heaters is 4200 ×
1.2 <Q ≤ 5600 x 1.2, the required heat quantity for 5 water heaters is 56
It is required to be 00 × 1.2 <Q ≦ 7000 × 1.2. Therefore, from these relationships, the number-of-units change reference calorie Q4 for changing the number of combustion from 5 to 4 units is 6720 kcal / min, and the number-of-units change reference heat amount Q3 for changing from 4 units to 3 units is 5040 kcal / min, 3 to 2 units Number of units change standard heat quantity Q2 to change to 3360 kcal / min, number of units change standard heat quantity Q1 to change from 2 to 1 unit is 1680 kcal / m
in, change the number of units to change from 1 to 0 units Reference heat quantity Q0 is 0k
cal / min. Then, ΔQ is set as the number of units increasing / decreasing differential heat quantity.

The unit change reference temperature is obtained from the unit change reference heat quantity. That is, the reference temperature T4 is obtained from Q4 and Equation 2. Reference temperature T to change the number of units from 5 to 4
4 becomes 6720 = (85-T4) × 350 and T4 = 65.8, and similarly T3 = 70.6, T2 = 75.4, T1 = 80.2. The control target temperature (upper limit reference temperature) and each reference temperature T1, T
The differential ΔT corresponding to the differential calorific value ΔQ is set for 2, T3 and T4.

The result thus obtained is illustrated in FIG. 2, and conceptually, the combustion instruction number is obtained according to FIG. Actually, the number controller C calculates the unit change reference heat amounts Q1, Q2, Q3, Q4 based on the signals of the heat output q _n of the water heater and the number N, the control target temperature T0, and the flow rate W which are input in advance, Based on these reference heat values and ΔQ, the combustion instruction number n
Is performed to control the number of units. The reference temperatures T1, T2, T
When the combustion instruction number n is determined by comparing T3, T4 and ΔT with the return hot water temperature tm, the reference heat quantity and Δ
This is equivalent to the case where the combustion instruction number n is obtained from Q.

The operation of the embodiment configured as described above will be described. Now, it is assumed that the maximum required heat quantity QM of the load F is equal to the total heat output 5q ₀ of the total water heater. First, the controller C obtains the required heat quantity Q from the equation 2 based on the flow rate W and the return hot water temperature tm, and also obtains the number-of-units change reference heat quantity Q1, Q2, Q3, Q4 from the detected circulation flow rate W as described above. Take control. Specifically, in FIG. 2, when the return hot water temperature tm is T4 or lower, that is, when the required heat quantity Q is Q4 or higher, a start instruction is given to all five water heaters. The activation is performed in order according to a predetermined priority and with a predetermined delay time so that they are not simultaneously activated. When the required heat amount Q becomes smaller than Q4, the combustion of the _fifth hot water generator B ₅ is stopped and the number of combustion instructions is set to 4. When the required heat quantity Q exceeds Q3 and decreases, the combustion of the _fourth hot water generator B ₄ is stopped and the number of combustion instructions is set to 3. In this way, the return hot water temperature tm rises,
That is, as the required heat quantity Q decreases, the burning boilers are sequentially stopped in accordance with a predetermined stop priority order. Then, when the required heat quantity Q exceeds Q0 and decreases, all the water heaters are stopped. On the contrary, when the return hot water temperature tm decreases, the required heat amount Q increases, and the required heat amount Q exceeds Q0 + ΔQ and decreases, the boiler B ₁ is activated and sequentially Q1 + ΔQ, Q2 + ΔQ, Q3.
The number of instructed combustions of the water heater is increased each time the number exceeds + ΔQ, Q4 + ΔQ and decreases.

According to this embodiment, the required amount of heat corresponding to one hot water machine is widened (handled), and the number of times the hot water machine is turned on and off can be reduced. As a result, the service life of the water heater can be extended and thermal loss due to pre-purge, post-purge and the like due to ON-OFF can be reduced, and the operation efficiency of the system can be improved.

The present invention is not limited to the above embodiments, and the following modified embodiments are also included in the embodiments of the present invention.

An automatic number control method for a cold water system using a cold water machine such as a chiller in place of the hot water machine of the above embodiment (referred to as the first embodiment) shown in FIGS. 1 and 2. in this case,
Only when the heat quantity heat output such as the necessary heat quantity becomes negative (negative), the number of units is controlled by the same formula as the system using the water heater, and the number of times of starting and stopping the water cooler is reduced as in the above embodiment. .

A method of controlling the number of units in a system in which some or all of the coefficients m _n are different from each other in the first embodiment or the embodiment. The effect of this embodiment is similar to that of the first embodiment.

The heat output q of some or all of the hot or cold water heaters B _n in the first embodiment or the embodiment or embodiments.
_A method for controlling the number of units in a system in which _n is different from each other.
The effects of this embodiment are similar to those of the first embodiment.

In any one of the above-mentioned embodiments, the number of units control method of the system in which the output of the water heater is not controlled by two-step control of ON-OFF but is controlled by three-step control of high-fuel / low-fuel-OFF. If in this case, to control, for example, the following n + 1 single second of warm water machine After the n stand eyes of the hot water machine and Tei燃→ high fire as Tei燃→ high fire ···, q _n is the high-fire time Heat output.

In any of the above embodiments, a means for measuring the circulating flow velocity in the passage as a means for detecting the circulating amount of hot water or cold water, or a differential pressure between the pressure at the hot water supply side collecting portion and the pressure at the return side collecting portion. Example using a means for measuring.

[0029]

As described above, according to the present invention, the range of required heat quantity corresponding to one hot water machine or cold water machine is widened, and the number of times of starting and stopping the hot water machine or cold water machine can be reduced, and the length of the equipment can be reduced. It has great effects such as life extension and system efficiency improvement.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a hot water system for realizing a number control method according to an embodiment of the present invention.

FIG. 2 is a diagram showing the concept of determining the number of units in the number control method according to the present invention.

[Explanation of symbols]

B _n Water heater K1 Hot water supply path (supply path) K2 Return path C Number controller P Circulation pump TC Temperature sensor F Flow rate sensor

Claims (4)

[Claims] 1. A output stages controlled N (≧ 2) stage of the water heater or water coolers B ₁ · · · B _N and hot or cold water system coupled to a load in hot or cold water supply line and the return path In the step of calculating the required heat quantity Q, the n hot-water or cold-water generators B ₁ ... B _n driven by the following equation (provided that the boilers are started in ascending order of n, and N ≧ n
And an integer of ≧ 1) are included. Formula: m ₁ q ₁ + ... + m _n-1 q _n-1 <Q ≦ m ₁ q ₁
+ ... + m _n q _n where q _n is the heat output of the hot or cold water generator B _{n mn} is 1 ≦ m _n , m ₁ q ₁ + ... + m _N-1 q _N-1 <
A coefficient that satisfies q ₁ + ... + q _N. 2. The method for controlling the number of hot water machines or cold water machines according to claim 1, wherein all m _n are equal. 3. The method for controlling the number of hot water machines or cold water machines according to claim 1 or 2, wherein all q _n are substantially equal. 4. The method of controlling the number of hot water machines or cold water machines according to claim 1, 2 or 3, including the step of obtaining the required heat quantity Q by the following equation. Q = (T0-tm) × W where T0 is the target temperature, tm is the return water temperature, and W is the flow rate.